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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to U.S. patent applications "Magnetic Resonance Guided Focussed Ultrasound Surgery" by Harvey Cline et al. Ser. No. 07/854,040 filed Mar. 19, 1992 now U.S. Pat. No. 5,427,935, "Magnetic Resonance Surgery Using Heat Waves Produced with Focussed Ultrasound" by Harvey Cline et al. Ser. No. 07/751,259 filed Aug. 29, 1991 now U.S. Pat. No. 5,291,890; "Magnetic Resonance Surgery Using Heat Waves Produced with a Laser Fiber" by Harvey E. Cline et al. Ser. No. 125,520 field Sep. 24, 1991; U.S. Pat. No. 5,153,546 open MRI. Magnets by Evangelos T. Laskaris issued Jun. 8, 1990; and "Open Gradient Coils for Magnetic Resonance Imaging" by William Barber et al. Ser. No. 08/146,346 fiel Nov. 2, 1993; all assigned to the present assignee and hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present application relates to magnetic resonance (MR) imaging system, and more specifically to MR Imaging system which allows access to the patient during imaging.
2. Description of Related Art
In Magnetic Resonance (MR) Imaging magnetic field gradients are produced over a patient desired to be imaged by energizing gradient coils which produce magnetic fields which interact with a static magnetic field produced by a main magnet. Radiofrequency (RF) excitation pulses produce RF energy which is radiated through the patient, nutating resonating nuclei "nuclear spins". These nutated nuclear spins produce a spatially dependent MR response signal when proper readout magnetic field gradients are applied to them. In order to produce accurate images, the main magnetic field must be spatially homogeneous over the imaging region. Also, the magnetic field gradients must also be spatially homogeneous.
Typically, to produce a homogeneous magnetic field over the patient, the main magnet has a cylindrical shape which surrounds the patient. The gradient coils are also cylindrically shaped and fit inside the main magnetic and also surround the patient. Access to the patient is, therefore, severely limited due to the geometry of the magnet and gradient coils. In addition to limited access, patients typically develop a claustrophobic reaction during imaging.
In order to provide MR images of a patient in conventional systems, the three dimensional position and orientation of a desired region of the patient to be imaged must be provided to the MR imaging system. The three dimensional orientation must also be provided, in addition to the location. These orientations must be calculated manually. Even though the computations may not be difficult, it makes it cumbersome to produce several images at different orientations.
Currently there is a need for an MR imaging system which provides MR images of selected internal structures of a patient undergoing a medical procedure in which a physician may easily indicate a desired region and a desired viewing angle.
SUMMARY OF THE INVENTION
An open magnetic resonance (MR) imaging system provides images of a patient undergoing a medical procedure. The MR imaging system having an open main magnet having a pair of tings with an imaging volume accessible by a physician positioned outside of the main magnet. A patient is positioned such that a region of the patient desired to be imaged is located within the imaging volume. The open main magnet produces a static magnetic field that is homogeneous over the imaging volume.
A gradient amplifier energizes the gradient coils, positioned within the open magnet rings, and produces a magnetic field gradient over the desired region of the patient in the imaging volume while providing access to the patient.
Open radiofrequency (RF) coils driven by an RF transmitter, transmit RF radiation into the patient causing nutation of nuclear spins within the desired region of the patient and do not restrict access to the patient.
A physician employs a pointing device to define a three-dimensional position and orientation of a plane desired to be imaged within the imaging volume. This information is provided in proper form to a general purpose computer which provides parameters to a pulse sequencer allowing an image defined by the pointing device to be created. The pulse sequencer controls a gradient amplifier and RF transmitter according to a prescribed pulse sequence. An MR response signal is generated by nuclear spins in the imaging plane of the patient.
A receiver receives the MR response signals and passes this signal to a reconstruction unit which computes an image signal from the MR response signal which is displayed on a display means to the physician performing the medical procedure, thereby aiding the physician.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a magnetic resonance (MR) imaging system which allows a physician to perform medical procedures on a patient, while the patient is being imaged.
Another object of the present invention is to provide MR images to a physician to aid the physician in performing medical procedures.
Another object of the present invention is to allow a physician to interactively select a position and orientation of imaging planes for MR images.
Another object of the present invention is to provide a MR imaging system which provides MR images of a patient while minimizing the claustrophobic reactions of the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to organization and method of operation together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawing in which:
FIG. 1 is a partial diagram of a prior art whole-body gradient coils, and conventional main magnet for a magnetic resonance (MR) imaging system.
FIG. 2a is a block diagram of a first embodiment of a magnetic resonance (MR) imaging system according to the present invention.
FIG. 2b is a block diagram of a second embodiment of a magnetic resonance (MR) imaging system according to the present invention.
FIG. 3 is a perspective, partial schematic view of an open MR imaging magnet, gradient coils and radiofrequency (RF) coils, of the MR imaging system of FIG. 2.
FIG. 4 is a perspective view of current paths disposed on gradient coil carriers to produce a gradient perpendicular to the "Z" axis according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic diagram of a portion of the apparatus used in conventional MR imaging. A magnet 15, usually a super-conducting magnet, surrounds the entire apparatus. A body gradient coil assembly 20 is shown as it would be implemented inside the magnet 15. The body gradient coil assembly 20 is comprised of four gradient coils each for the "X" and "Y" axes, which resemble a fingerprint, called fingerprint coils 22, 24, 26 and 28. Current is passed through the fingerprint coils by a power supply 21. Power supply 21 provides a current which passes through fingerprint coil 22 in a direction marked by arrow 21a. Similarly, power supply 21 supplies current which passes through fingerprint coils 24, 26 and 28 in the direction marked by arrows 23a, 25a and 27a , respectively.
Due to its geometry, access to the patient is limited only to openings at either end of the whole body gradient coil set.
A block diagram of the magnetic resonance (MR) imaging system of the present invention is shown in FIG. 2a. A patient 10 is positioned within an open main magnet, having two superconducting tings 2, 4, is arranged as a modified "Helmholtz pair" which provides a static, spatially homogeneous magnetic field over an imaging volume between the tings. The spacing between the tings is slightly different from that of a "Helmholtz pair" in order to elongate the imaging volume, and is therefore termed a "modified Helmholtz pair". A gradient amplifier 50 provides power to a plurality of gradient coil sets located within tings 2, 4, each producing a magnetic field gradient in a specified direction. An RF transmitter 60, supplies the necessary power to RF coils to nutate nuclear spins within a patient in the imaging volume. The gradient coil sets within rings 2, 4 produce magnetic field gradients over the imaging volume without restricting access to the imaging volume, or the patient within the imaging volume.
A physician may use a pointing device to indicate a region of patient 10 to be imaged. Not only can the pointing device indicate where the image is to be acquired, but can indicate the orientation in which it is to be viewed. The plane of the patient in which the image is acquired is known as the "imaging plane". Many different devices can be used to identify the imaging plane.
In FIG. 2a, a set of infrared cameras act as tracking unit 71 (in the preferred embodiment were manufactured by the PIXSYS corporation) track the positions of two light emitting diodes (LEDs) on a hand-held pointer 73. A physician points pointer 73 at a region of patient 10 desired to be imaged. Since tracker 71 knows the position of the LEDs of pointer 73, it may easily calculate a direction in which pointer 73 is pointing and its location. The physician then indicates a distance along this direction to uniquely define an imaging plane perpendicular to this direction. The distance along the direction of pointer 73 may be provided to general purpose computer by a footswitch 79 via controller 75. The distance may be a preset distance, or be manually provided to an operator's console 101 of general purpose computer 100.
In the embodiment of FIG. 2b, a mechanical arm 76 (in the preferred embodiment manufactured by the FARO corporation) is attached to the inner face of the magnet tings 2, 4 which provide a position reference. Sensors on joints 78 of mechanical arm 76 indicate the position and orientation of pointer 73.
Other embodiments of the pointing device may employ a second RF transmitter having several transmitter coils attached to pointer 73. The second RF transmitter may be self-contained within pointer 73 or be connected to the transmitter coils on pointer 73. Tracking unit 71 has several receive coils which receive the signal transmitted by the transmitter coils on pointer 73 and determines the location of the transmitter coils. Since their relative position on pointer 73 is fixed, the direction in which the pointer is pointing, and the location of pointer 73 may be determined. Since reciprocity exists between transmitter and receiver coils, the transmitter coils may be positioned external to the pointer with receiver coils attached to pointer 73. The signals received by pointer 73 are then passed to tracking unit This type of tracking device was disclosed in U.S. Pat. No. 5,211,165 "Tracking System to Follow the Position and Orientation of a Device with Radiofrequency Field Gradients" by Dumoulin, Darrow, Schenck, Souza issued May 18, 1993.
Controller 75 receives the image plane information and provides this information to general purpose computer 100 which activates a pulse sequencer 105. Pulse sequencer 105 controls the timing and activation of gradient amplifier 50 and RF transmitter 60 to produce magnetic field gradients and RF radiation which cause an MR response signal to be emitted by tissue of patient 10 in the imaging plane.
MR tracking devices such as those disclosed in U.S. patent application "Tracking System to Monitor the Position and Orientation of a Device Using Magnetic Resonance Detection of a Sample contained Within the Device" by Charles L. Dumoulin, Steven P. Souza, Robert D. Darrow Ser. No. 07/861,662 filed Apr. 1, 1992 may also be employed to track the position and orientation of pointer 73 to determine the imaging plane, however, they do not require tracking unit 71. Pointer 73 has a receiver attached to it which detects magnetic reference signals responsive to a tracking pulse sequence.
A receiver 90 receives the emitted MR response signal from the imaging plane of patient 10, and provides this signal to a reconstruction unit 95. Reconstruction unit 95 produces data for an MR image of patient 10 at the imaging plane. The image data is provided to general purpose computer 100 which displays an MR image on operator's console 101. An output of the operator's console 101 provides the data to a scan converter 103 which changes the format of the signal and provides it to a display 110. The image of the imaging plane is displayed to the physician on display 110 to aid the physician during medical procedures such as surgery.
Display device 110 may be located near the physician. Due to the large magnetic fields the display device would be have to be a liquid crystal display. Also since there is substantial RF radiation, it should be enclosed in a suitable RF shielding to minimize RF interference.
Another method of displaying images to the physician is by employing a projection television located outside the magnet room with images projected onto a screen located within the viewing area of the physician.
Footswitch 79 or other input device such as a foot pedal near the magnet controls may also be used to control the scanner timing and provide rudimentary controls such as changing scan modes or scan type. This may be used to toggle between spin echo imaging, gradient echo imaging or any other menu of preset parameters.
The present invention may be implemented to obtain an image of the tissue at some depth below the surface to locate a tumor, a blood vessel or nerve. It may be employed in guiding placement of a biopsy needle or a laser fiber. Images could be also be acquired parallel to the direction of pointing device 73 with another input specifying the last degree of freedom Images taken parallel to the vector might be particularly useful in showing the trajectory of biopsy needle, laser fiber or other surgical device.
The present invention may execute many types of pulse sequences including real-time temperature-sensitive MR pulse sequences as described in U.S. patent application "Heat Surgery System Monitored by Real-Time Magnetic Resonance Profiling" by Christopher J. Hardy and Harvey E. Cline Ser. No. 08/038,204, filed Mar. 26, 1993. This will allow the physician to image heated regions in addition to interval structures to selectively heat desired tissues.
Open magnets have been recently introduced as described in the aforementioned U.S. patent application by Laskaris. These are acceptable for use with the present invention.
Since most gradient conventional gradient coil designs require a major portion of their current carrying conductors to be near the central region, the use of conventional gradient coils would obstruct the open area provided by the open magnet, thereby defeat the purpose of the open magnet.
In order to provide maximum access to the patient, carriers on which the gradient coils would be disposed, were restricted to fit within regions within the bores of the tings of the open magnet. Classical potential theory requires the current surface be as close to the desired useful volume as possible and subtend as large a solid angle as possible for greatest efficiency.
In order to actively cancel eddy currents in a most efficient way, the shield coils must be positioned as near as possible to the surface where cancellation is desired. The shield coil should also have a current density distribution as similar to that induced on a nearby conductor to provide eddy current cancellation.
In FIG. 3, the open main magnet of FIG. 2 is shown in enlarged view having two tings 2, 4, each containing one or more circular superconducting coils. Access to the patient is allowed between the tings in an open region 9 where a substantially uniform magnetic field is produced midway between the tings. The magnetic field gradient, in the X or Y directions, or for that matter, any direction perpendicular to the axis of the tings (the Z direction), is produced by two coils on one gradient coil carrier 30 and two coils on a second gradient coil carrier 40. Gradient coil carders 30, 40 each are comprised of a cylinder 33, 43 connected to a flange 35, 45 with two coils, each partially disposed on the cylinder and the flange. An opening 6, 8 in the center of each carder 30, 40 may receive the patient being imaged, or the patient may be positioned such the the region being imaged is placed within imaging volume 9.
In order to produce the required gradients over imaging volume 9 for MR imaging, several sets of gradient coils must be constructed. At least one set produces a magnetic field gradient in a "Z" direction along the length of the carrier cylinder. At least one other gradient coil set produces gradients in directions perpendicular to the carrier cylinder axis. These may be in the "X" and "Y" directions. Current is driven through the "X", "Y", and "Z" gradient coil sets by gradient coil amplifiers 3, 5, and 7, which together are represented as gradient amplifier 50 of FIG. 2.
In order to minimize the eddy currents produced in nearby conductors, an active shield coil is serially connected to each gradient coil set distributed onto the surface of a shield coil carder which lines the bore of the main magnet structure.
FIG. 4 is a perspective view of current paths to produce a gradient perpendicular to the "Z" axis disposed on gradient coil carders 30, 40. A coil 37 is disposed on one side of carrier 30 with a second coil 39 disposed on the other side such that a line passing through the center of the coils would pass through opening 6. Coils 37, 39 are comprised of a plurality of turns, each turn partially disposed on the cylinder, denoted by 37a, 39a, and partially disposed on the flange, 37b, 39b. Similarly, two coils 47, 49 are disposed opposite each other on carder 40. Each coil having a portion 47a, 49a disposed on the flange and a portion 47b, 49b disposed on the cylinder. The current flow to produce a magnetic field gradient in a direction perpendicular to the "Z" direction is shown by arrows 37c, 39c, 47c, 49c, for coils 37, 39, 47, 49, respectively.
If coils 37, 39, 47, 49 are positioned such that the "X" axis passes through their centers, they will produce a magnetic field gradient in the "X" direction. In order to produce a gradient in the "I" direction, another set of coils, the same as the first set, should be disposed on the gradient coil carriers rotated at a 90 degree angle relative to the first set of gradient coils.
While several presently preferred embodiments of the novel open imaging system have been described in detail herein, many modifications and variations will now become apparent to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and variations as fall within the true spirit of the invention. | A magnetic resonance (MR) imaging system for use in a medical procedure employs an open main magnet allowing access to a portion of a patient within an imaging volume, for producing a main magnetic field over the imaging volume; a set of open gradient coils which provide magnetic fields gradients over the imaging volume without restricting access to the imaging volume; a radiofrequency coil set for transmitting RF energy into the imaging volume to nutate nuclear spins within the imaging volume and receive an MR response signal from the nuclear spins; and a pointing device for indicating the position and orientation of a plane in which an image is to be acquired; an image control means for operating power supplies for the gradient coils and the RF coils to acquire an MR signal from the desired imaging plane; and a computation unit for constructing an image of the desired imaging plane. The MR imaging system is intended to operate to provide images to a physician during medical procedures to guide the physician in his procedures. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vacuum envelope that houses electron sources and electrodes each for gathering electrons emitted from an electron source. Particularly, the present invention relates to a flat vacuum envelope that houses field emission elements (field emission cathodes) each acting as an electron source and to a method for evacuating the same.
2. Description of the Related Art
Recently, the field emission electronic equipment, which includes a large number of micro field emission elements contained in a glass vacuum envelope and integrated in a vacuum micro-structure, is proceeding toward practical use as a vacuum microelectronic element.
As applications of the vacuum microelectronics technology, field emission devices including flat field emission display panels, pick-up tubes, electron beam lithography apparatuses, and the equivalents have been studied.
In a flat display panel embodying field emission elements, one pixel corresponds to a specific number of micro-cold cathodes (emitters).
Various types of cathodes including field emission elements, MIN-type electron emission elements, surface conduction-type emission elements, PN-junction-type electron emission elements, and others, each having a pointed end, have been proposed as the micro cold cathode.
As one most typical example, a field emission device (FED) is disclosed in “NIKKEI ELECTRONICS”, No. 654, Jan. 29, 1996, pp. 89-98. In the FED device, the so-called Spindt type field emission element (FED) is well known.
In the Spindt field emission element, a large number of emitter electrodes E are formed on the cathode substrate K, as shown in FIG. 6 . An insulating layer SiO 2 is laid over the cathode substrate K. A gate electrode GT is vapor-deposited over the insulating layer. Holes are formed in the gate electrode so as to expose the point of an emitter electrode E via each hole.
When a voltage Vgk is applied between the cathode electrode K and the gate electrode GT, the point of emitter electrode E emits electrons. An anode electrode A is placed so as to confront the cathode electrode K in the vacuum space. When an anode voltage Va is applied between the cathode electrode K and the anode electrode A, the anode electrode (A) gathers the emitted electrons. The field emission elements are arranged in group. When stripe gate electrodes are sequentially scanned while image signals are supplied to stripe cathode electrodes, the fluorescent materials coated on the cathode electrodes glow so that the display device operates as an indicator.
FIG. 7 ( a ) is a perspective view illustrating the envelope of the above mentioned display panel. FIG. 7 ( b ) is a side cross sectional view illustrating the envelope of the above mentioned display panel.
Referring to FIGS. 7 ( a ) and 7 ( b ), reference numeral 1 represents a glass substrate on the side of the anode (hereinafter referred to as an anode substrate) and 2 represents a glass substrate on the side of the cathode (hereinafter referred to as a cathode substrate). Micro-field emission elements are formed on the anode substrate so as to confront the cathode substrate. Anode electrodes are formed on the anode substrate so as to confront the cathode substrate.
The getter substrate 3 has the lower surface on which an exhaust hole 3 a is formed to evacuate the inside of the envelope to a vacuum state. The getter 4 is for example, an evaporation-type getter. The getter is flashed at a high temperature after evacuating the envelope so that the inside of the envelope can be maintained to a high vacuum degree.
The juxtaposed structure of the cathode substrate 2 and the anode substrate 1 are sealed with a fritted glass 5 while the cathode substrate 2 is spaced from the anode substrate 1 by a small distance of 200 μm to 500 μm apart. The substrates 1 and 2 are generally arranged to be mutually shifted. Thus, the cathode electrode leads and gate electrode leads of the field emission elements can be placed to the portions where the substrates 1 and 2 do not confront from each other.
In the case of color displaying, anode electrode leads can be arranged on the cut portion (not shown) protruding toward the anode substrate.
As described above, the gap between the fringe of the cathode substrate 2 and the fringe of the anode substrate 1 are sealed with a fritted glass 5 , except the getter substrate 3 . An exhaust tube (not shown) is connected to the getter substrate 3 to evacuate the inside of the envelope by a vacuum pump.
In the vacuum envelope contains field emission elements, the cathode substrate 2 is separated from the anode substrate 1 by a small distance. In order to maintain the space of the envelope in a high vacuum degree, the evaporation-type getter 4 is generally disposed in the getter room. The getter 4 is vaporized by externally heating it at a high temperature. A getter mirror, which can adsorb the residual gas ousted from the electronic material or adsorbed after the evacuation step, is formed over the entire surface of the getter room.
In the flat display panel, since the very narrow space (t) of the vacuum envelope has a poor conductance to the gas flowing it, it is difficult that a vacuum pump draws the vacuum space to a high vacuum degree.
The ratio of the material for forming the existing field emission elements to the volume of the vacuum space is high. Hence, the evacuating process must be performed for a long time to bring the envelope to a predetermined vacuum degree by exhausting the remaining gas (particularly, moisture) adsorbed inside of the constituent materials.
In order to achieve a higher vacuum degree, the well-known getter flashing is performed after the evacuation process. Thereafter, the whole vacuum envelope is placed in an oven at about 200° C. for several hours to adsorb the remaining gas in the vacuum envelope. This makes the fabricating process more complex. The long evacuating step (e.g. 220 minutes) prolongs the product completion time.
SUMMARY OF THE INVENTION
The present invention is made to solve the above-mentioned problems.
Moreover, the objective of the invention is to provide a vacuum envelope that can improve the vacuum degree in a field emission device.
Another objective of the present invention is to provide a vacuum envelope evacuating method that can effectively evacuate gas remaining in the vacuum envelope.
The objective of the present invention is achieved by a vacuum envelope comprising a first substrate formed of a glass substrate; a second substrate arranged so as to confront the first substrate; and a side wall for separating the first substrate from the second substrate by a predetermined distance to form a space therebetween; wherein a first opening used to evacuate the inside of the envelope is formed in a part of a vacuum envelope assembled by the first substrate, the second substrate and the side wall; and wherein a second opening is formed in a part of the vacuum envelope, the second opening being sealed at a different position of the vacuum envelope, different from the position of the first opening. Thus, before sealing in a vacuum state, the envelope is backed while high temperature gas is being flowed using the first opening and the second opening.
According to the present invention, the vacuum envelope further comprises field emission elements formed on the first substrate and an anode electrode formed on the second substrate so as to confront the field emission elements.
According to the present invention, the vacuum envelope further comprises a getter room placed so as to cover the first opening.
Furthermore, a method for evacuating a vacuum envelope, comprises the steps of juxtaposing a first substrate and a second substrate so as to be spaced from each other a predetermined distance apart, the first substrate on which field emission elements are formed; temporarily framing the periphery of the first substrate and the periphery of the second substrate with fritted glass to form an envelope; introducing a gas at a high temperature for a predetermined period of time to flow through the envelope; sealing an outlet, except a main opening into which the gas is introduced; and evacuating the inside of the envelope to a vacuum state through the main opening, so that the envelope is maintained in a vacuum state.
According to the present invention, the method further comprises the step of previously forming at least two openings on a side portion of the envelope temporarily assembled.
In the method according to the present invention, the gas at a high temperature is selected from the group consisting of CO (carbon monoxide), N 2 , H 2 , and a mixed gas of an inert gas and CO, N 2 , or H 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
This and other objects, features, and advantages of the present invention will become more apparent upon a reading of the following detailed description and drawings, in which:
FIG. 1 is a schematic diagram illustrating an envelope evacuating method according to the present invention;
FIGS. 2 ( a ), 2 ( b ) and 2 ( c ) are diagrams for explaining the process of evacuating a vacuum envelope;
FIG. 3 is a perspective view illustrating a flat vacuum envelope;
FIGS. 4 ( a ), 4 ( b ) and 4 ( c ) are diagrams for explaining the process of evacuating a flat envelope;
FIGS. 5 ( a ) and 5 ( b ) are diagrams explaining high temperature gas flowing inside an envelope;
FIG. 6 is a schematic perspective view partially illustrating a vacuum envelope; and
FIGS. 7 ( a ) and 7 ( b ) are diagrams explaining a field emission element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be described below with reference to the attached drawings.
FIG. 1 shows a device embodying the envelope evacuating method according to the present invention.
Referring to FIG. 1, reference numeral 10 represents a vacuum envelope of which the inside space is not in a sealed state, or in a pre-completion state. In FIG. 1, the same constituent elements as those of FIG. 7 are represented with like numerals.
In a sealing chamber 11 , the vacuum envelope 10 is fixed with a supporting tool (not shown) and is heated by a heating apparatus. The sealing chamber 11 can be constructed of a furnace that can heat the sealing chamber 11 at temperatures at which the fritted glass 5 is melted.
An intake and exhaust chamber 12 is equipped under the sealing chamber to blow a high temperature gas into the vacuum envelope 10 or to evacuate the inside of the vacuum envelope 10 (as described later).
An elevating rod 13 ascends and descends when a pressure is applied to the cylinder room 13 b . One end of the elevating rod 13 is formed of a head 13 a on which a sealing body 17 for sealing the vacuum envelope 10 is placed.
A vacuum pump 14 is controlled to evacuate the inside of the intake and exhaust chamber 12 through the second valve 15 .
A first valve 16 is opened to introduce a gas at a high temperature into the intake and exhaust chamber 12 (in the arrow direction).
The end of the elevating rod 13 is supported in the inner cylinder 18 and sidably driven by a drive mechanism (not shown). A flexible sealing body 18 a is placed on the end of the cylinder 18 to hermetically seal with the getter room 3 when it is contacted against the getter room of the vacuum envelope 10 . The cylinder chamber 13 b vertically moves the elevating rod 13 .
According to the present invention, when the vacuum envelope 10 is conveyed into the sealing chamber 11 , the opening is left around the periphery of the fritted glass 5 laminated on the vacuum envelope 10 . Hence, as described later with reference to FIG. 2, a high vacuum space can be obtained while the gas remaining inside the vacuum envelope 10 is being evacuated.
That is, as shown in FIG. 2 ( a ), the inner cylinder 18 is first lifted to be in strong contact with the vacuum envelope 10 conveyed inside the sealing chamber 11 . In such a state, the first valve 16 is opened to introduce gas at a high temperature into the vacuum envelope 10 , as shown by the arrows.
Since the fritted glass 5 to be formed as the side wall of the vacuum envelope 10 is not completely sealed, the gas charged into the envelope 10 flows through the space between the first substrate 11 and the second substrate 12 in the arrow direction. The gas flows through the space in the vacuum envelope 10 and then is discharged out through the fritted glass portion 5 not sealed.
The flow of the high temperature gas allows the gas contents (mainly, moisture) remaining inside the envelope 10 to be exhausted sufficiently.
The gas temperature depends on the volume of the envelope 10 and is preferably 300° C. to 500° C. The gas flowing time depends on the temperature and is preferably several minutes to several hours.
After the high temperature gas is sufficiently flowing, the sealing chamber 11 is controlled to an elevated temperature. Thus, the fritted glass 5 applied to the peripheral portion of the envelope 10 is melted. Then the gas flowing through the envelope 10 is stopped.
At this time, it can be detected that the peripheral portion of the envelope 10 has been completely sealed with the fritted glass 5 by monitoring the pressure of the high temperature gas supplied.
After the complete sealing state is ascertained, the first valve 1 is closed to stop supplying the high temperature gas while the second valve 15 is opened.
The second valve 15 forms an exhaust passage to the vacuum pump 14 . The vacuum pump 14 evacuates the gas remaining inside the envelope 10 in the arrow direction. The envelope 10 is evacuated, for example, to a vacuum degree of 10 −3 to 10 −5 Pa.
After the envelope 10 is evacuated to a sufficient vacuum state, the elevating loader 13 is lifted as shown in FIG. 2 ( c ). Thus, the glass sealing body 17 placed on the head 13 a is pushed against the exhaust inlet 3 a of the getter room of the envelope 10 . The heating device inside the sealing chamber 11 welds the portion around the exhaust inlet 3 a with the sealing body 17 .
In this welding step, the envelope 10 is maintained in a vacuum state. The envelope 10 is fed out by means of a conveying mechanism (not shown). Thereafter, the next envelope is conveyed into the evacuating chamber.
According to the same fabrication process, a flat envelope for a display panel can be fabricated. In that embodiment, since the exhaust inlet 3 a of the vacuum envelope is formed with the getter room, the envelope can be increased to a higher vacuum degree by flashing the evaporation-type getter, in a similar manner to that to the common vacuum envelope. Thus, the envelope can be sustained to a higher vacuum state.
FIG. 3 is a perspective view illustrating the envelope 20 according to another embodiment of the present invention.
In this embodiment, the envelope 20 is formed of a first substrate 21 having the inner surface on which field emission elements are formed, a second substrate 22 is arranged so as to confront the field emission elements and having anode electrodes for gathering electrons emitted from the field emission elements are formed, and a side wall 23 for hermetically sealing the space between the first substrate 21 and the second substrate 22 .
As shown in FIG. 3, the envelope 20 has a first opening 24 a and a second opening 24 b opened vertically in the sidewall 23 . Before the sealing step, the sucked gas flows from the first opening 24 a to the second opening 24 b.
Clips (or tapes) 25 , 25 , . . . temporarily fix the first glass substrate 21 and the second glass substrate 22 . Glass sealing body 26 a is a member used for sealing the first opening while the glass sealing body 26 b is a member used sealing the second opening.
The glass sealing members ( 26 a, 26 b ) are respectively supported by the welding heating members ( 27 a, 27 b ) and are welded to hermetically seal the inside of the envelope after the evacuating step (as described later).
In the embodiment, a vacuum envelope 20 is completed by flowing a gas, e.g. CO, N 2 , H 2 , or a mixture of one of them and an inert gas, at a high temperature, into the inside of the envelope and then evacuating the envelope to a high vacuum state.
That is, as shown in FIG. 4 ( a ), first, the heating members 27 a and 27 b are separately disposed at both the ends of the envelope 20 . A high temperature gas is charged into the envelope 20 via the inner cylinder 20 , in the arrow direction. The gas passing through the envelope 20 is discharged from the opening 24 a.
By flowing the high temperature gas, the degassing and evacuating preliminary step is performed which blows out gas contents adhered on and left inside the envelope and sweeps out moisture adhered on various devices or material contained in the envelope.
Next, as shown in FIG. 4 ( b ), the heating member 27 a on the side of the second opening 24 a butts against the sealing member 26 a. The second opening 24 a is welded and sealed with the sealing member 26 a through the heating operation.
After the completion of the welding step, the vacuum pump is driven to evacuate the inside of the envelope 20 from the first opening 24 b. When the inside of the envelope is evacuated to a sufficient vacuum state, the first opening 24 b is sealed with the sealing member 26 b. Thereafter, the vacuum envelope is detached from the inner cylinder 18 and then is taken out of the sealing chamber.
That embodiment evacuates the getter room 3 but requires the flat inner cylinder 18 which directly blows and exhausts a gas at a high temperature from the opening formed in the side wall of the envelope. However, a very flat, slim vacuum envelope can be fabricated.
After the evacuation step, tape-like non-evaporation-type getters or flat, wire evaporation getters may be previously incorporated at the four corners of the envelope. Thus, the unwanted residual gases can be adsorbed by activating the getter after formation of the envelope.
As described above, the present invention is characterized in that high temperature gases are flown through the inside of the envelope in the previous evacuating step. In the envelope, at least two openings must be previously formed to improve the residual gas sweeping effect due to the high temperature gas flowing operation.
In order to flow gas smoothly in the flat space, it is required to effectively match the gas pressure, the opening area, and the viscosity resistance of the flowing path.
As well known in the vacuum technology, the flow of gas becomes turbulent at a high gas pressure, becomes a viscosity flow at a low gas pressure, and becomes a molecular flow at a lower gas pressure.
According to the present invention, it is preferable to increase the residual gas exhausting effect by decreasing the conductance to gas flowing in the envelope, as shown in FIGS. 5 ( a ) and 5 ( b ) and by setting the gas pressure, the positions of openings H 1 , H 2 , H 3 , H 4 , and H 5 , and the number of openings to obtain a viscosity region with good efficiency, under the above-mentioned flow conditions.
As described above, in the vacuum envelope and the vacuum envelope evacuating method according to the present invention, an opening, which allows gas at high temperature to flow through the envelope, is previously formed and the inside of the envelope is effectively baked before evacuation to oust the residual gas. Hence, the remaining gas is effectively exhausted in the post evacuation steps so that the narrow space can be brought to a high vacuum state in a relatively short time.
Moreover, the vacuum envelope can be more small-sized by sealing the evacuation chamber with a chipless cover or by omitting the getter room.
In the flat display panel employing field emission elements, the amount of gas remaining in the vacuum envelope largely depends on the product serviceable life and the quality. However, in spite of such a problem, the second embodiment of the present invention, a small, slim vacuum envelope can be fabricated by omitting the getter room. | A vacuum envelope that can improve the vacuum degree in a field emission device is provided. The vacuum envelope includes the cathode side substrate 2 on which field emission elements are formed and the anode substrate 1 spaced by a predetermined distance in the electron emission direction. At least two openings are formed before sealing the vacuum envelope. The remaining gas is ousted from the vacuum envelope by introducing a high temperature gas inside the vacuum envelope for a predetermined period of time. Thereafter, one of the openings is sealed while the envelope is being evacuated to a vacuum state through the remaining openings. | 7 |
BACKGROUND
A plasma processing apparatus generates a plasma in a chamber which can be used to treat a workpiece supported by a platen in a process chamber. In some embodiments, the chamber in which the plasma is generated is the process chamber. Such plasma processing apparatus may include, but not be limited to, doping systems, etching systems, and deposition systems. In some plasma processing apparatus, ions from the plasma are attracted towards a workpiece. In a plasma doping apparatus, ions may be attracted with sufficient energy to be implanted into the physical structure of the workpiece, e.g., a semiconductor substrate in one instance.
In other embodiments, the plasma may be generated in one chamber, which ions are extracted from, and the workpiece is treated in a different process chamber. One example of such a configuration may be a beam line ion implanter where the ion source utilizes an inductively coupled plasma (ICP) source. The plasma is generally a quasi-neutral collection of ions (usually having a positive charge) and electrons (having a negative charge). The plasma has an electric field of about 0 Volts per centimeter in the bulk of the plasma.
Turning to FIG. 1 , a block diagram of one exemplary plasma processing apparatus 100 is illustrated. The plasma processing apparatus 100 includes a process chamber 102 defining an enclosed volume 103 . A gas source 104 provides a primary dopant gas to the enclosed volume 103 of the process chamber 102 through the mass flow controller 106 . A gas baffle 170 may be positioned in the process chamber 102 to deflect the flow of gas from the gas source 104 . A pressure gauge 108 measures the pressure inside the process chamber 102 . A vacuum pump 112 evacuates exhausts from the process chamber 102 through an exhaust port 110 . An exhaust valve 114 controls the exhaust conductance through the exhaust port 110 .
The plasma processing apparatus 100 may further includes a gas pressure controller 116 that is electrically connected to the mass flow controller 106 , the pressure gauge 108 , and the exhaust valve 114 . The gas pressure controller 116 may be configured to maintain a desired pressure in the process chamber 102 by controlling either the exhaust conductance with the exhaust valve 114 or a process gas flow rate with the mass flow controller 106 in a feedback loop that is responsive to the pressure gauge 108 .
The process chamber 102 may have a chamber top 118 that includes a first section 120 formed of a dielectric material that extends in a generally horizontal direction. The chamber top 118 also includes a second section 122 formed of a dielectric material that extends a height from the first section 120 in a generally vertical direction. The chamber top 118 further includes a lid 124 formed of an electrically and thermally conductive material that extends across the second section 122 in a horizontal direction.
The plasma processing apparatus further includes a source 101 configured to generate a plasma 140 within the process chamber 102 . The source 101 may include a RF source 150 such as a power supply to supply RF power to either one or both of the planar antenna 126 and the helical antenna 146 to generate the plasma 140 . The RF source 150 may be coupled to the antennas 126 , 146 by an impedance matching network 152 that matches the output impedance of the RF source 150 to the impedance of the RF antennas 126 , 146 in order to maximize the power transferred from the RF source 150 to the RF antennas 126 , 146 .
In some embodiments, the planar antenna 126 and helical antenna 146 comprise a conductive material wound in a spiraling pattern. For example, FIG. 2A shows one embodiment of a traditional planar antenna 126 , while FIG. 2B shows a second embodiment. FIG. 3 shows a traditional helical antenna 146 .
Turning back to FIG. 1 , the plasma processing apparatus may also include a bias power supply 190 electrically coupled to the platen 134 . The plasma processing system may further include a controller 156 and a user interface system 158 . The controller 156 can be or include a general-purpose computer or network of general-purpose computers that may be programmed to perform desired input/output functions. The controller 156 may also include communication devices, data storage devices, and software. The user interface system 158 may include devices such as touch screens, keyboards, user pointing devices, displays, printers, etc. to allow a user to input commands and/or data and/or to monitor the plasma processing apparatus via the controller 156 . A shield ring 194 may be disposed around the platen 134 to improve the uniformity of implanted ion distribution near the edge of the workpiece 138 . One or more Faraday sensors such as Faraday cup 199 may also be positioned in the shield ring 194 to sense ion beam current.
In operation, the gas source 104 supplies a primary dopant gas containing a desired dopant for implantation into the workpiece 138 . The source 101 is configured to generate the plasma 140 within the process chamber 102 . The source 101 may be controlled by the controller 156 . To generate the plasma 140 , the RF source 150 resonates RF currents in at least one of the RF antennas 126 , 146 to produce an oscillating magnetic field. The oscillating magnetic field induces RF currents into the process chamber 102 . The RF currents in the process chamber 102 excite and ionize the primary dopant gas to generate the plasma 140 .
The bias power supply 190 provides a pulsed platen signal having a pulse ON and OFF periods to bias the platen 134 and hence the workpiece 138 to accelerate ions 109 from the plasma 140 towards the workpiece 138 . The ions 109 may be positively charged ions and hence the pulse ON periods of the pulsed platen signal may be negative voltage pulses with respect to the process chamber 102 to attract the positively charged ions. The frequency of the pulsed platen signal and/or the duty cycle of the pulses may be selected to provide a desired dose rate. The amplitude of the pulsed platen signal may be selected to provide a desired energy.
FIG. 4 shows a block diagram of a conventional ion implanter 300 . Of course, many different ion implanters may be used. The conventional ion implanter may comprise an ion source 302 that may be biased by a power supply 301 . The system may be controlled by controller 320 . The operator communicates with the controller 320 via user interface system 322 . The ion source 302 is typically contained in a vacuum chamber known as a source housing (not shown). The ion implanter system 300 may also comprise a series of beam-line components through which ions 10 pass. The series of beam-line components may include, for example, extraction electrodes 304 , a 90° magnet analyzer 306 , a first deceleration (D 1 ) stage 308 , a 70° magnet collimator 310 , and a second deceleration (D 2 ) stage 312 . Much like a series of optical lenses that manipulate a light beam, the beam-line components can manipulate and focus the ion beam 10 before steering it towards a workpiece or wafer 314 , which is disposed on a workpiece support 316 .
In operation, a workpiece handling robot (not shown) disposes the workpiece 314 on the workpiece support 316 that can be moved in one or more dimensions (e.g., translate, rotate, and tilt) by an apparatus, sometimes referred to as a “roplat” (not shown). Meanwhile, ions are generated in the ion source 302 and extracted by the extraction electrodes 304 . The extracted ions travel in a beam-like state along the beam-line components and implanted on the workpiece 314 . After implanting ions is completed, the workpiece handling robot may remove the workpiece 314 from the workpiece support 316 and from the ion implanter 300 .
The ion source 302 may be an inductively coupled plasma (ICP) ion source. In some embodiments, such as in FIGS. 5A-B , the ion source 302 may comprise a rectangular enclosure, having an extraction slit 335 on one side 337 . In certain embodiments, the side 336 opposite the extraction slit 335 may be made of a dielectric material, such as alumina, such that a planar antenna 338 may be placed against the dielectric wall 336 to create a plasma within the enclosure 302 . The enclosure 302 also has a top surface 339 , a bottom surface 341 , and two endwalls 338 , 340 .
In another embodiment, a helical antenna 350 is wrapped around the endwalls 338 , 340 and the top surface 339 and bottom surface 341 of the ion source 302 .
One drawback of conventional plasma processing is the creation of metals within the chamber. These metals are generally generated by ions bombarding the walls of the dielectric window of the plasma-generating source at high energy. In inductively coupled RF plasmas, there is a capacitive component due to the high voltages on the RF coil. This capacitive component creates an electric field that is responsible for the metal generation in the RF source. Therefore, there is a need for an RF source which produces the magnetic field necessary for inductively generating a plasma without the associated electrical field or with a significantly decreased associated electrical field.
SUMMARY
A RF source and method are disclosed which inductively create a plasma within an enclosure without the associated electric field or with a significantly decreased creation of an electric field. A ferrite material is used to create a magnetic field. An insulated wire is wrapped around the body of the ferrite, which creates a magnetic field between the legs of the ferrite. This magnetic field can then be used to create a plasma. In one embodiment, these legs rest on a dielectric window, such that the magnetic field passes into the chamber. In another embodiment, the legs of the ferrite extend into the processing chamber, thereby further extending the magnetic field into the chamber. This RF source can be used in conjunction with a PLAD chamber, or an ion source for a traditional beam line ion implantation system.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present disclosure, reference is made to the accompanying drawings, in which like elements are referenced with like numerals, and in which:
FIG. 1 is a block diagram of a plasma processing apparatus of the prior art;
FIGS. 2A-B illustrate planar antenna of the prior art;
FIG. 3 illustrates a helical antenna of the prior art;
FIG. 4 is a block diagram of a ion implantation apparatus;
FIG. 5A is a front view of one embodiment of an ICP source;
FIG. 5B is a rear view of the embodiment of FIG. 5A ;
FIG. 6 is a cross-sectional view of an embodiment of the transformer coupled RF source resting on a dielectric window;
FIG. 7A is a cross-sectional view of an embodiment of the transformer coupled RF source extending into the plasma processing chamber;
FIG. 7B is a cross-sectional view of an embodiment of the transformer coupled RF source resting on a dielectric window with separate ferrite extensions on the opposite side of the window;
FIG. 8 is top view of a first embodiment of the transformer coupled RF source of FIG. 6 or FIG. 7 ;
FIG. 9 is a top view showing several RF sources of FIG. 8 positioned on a dielectric window;
FIG. 10 is a cross-sectional view of a PLAD chamber showing the embodiment of FIG. 9 ;
FIG. 11 is a top view of a second embodiment of the transformer coupled RF source of FIG. 7 ; and
FIG. 12 shows a perspective view of an ion source for a beam line implanter using the embodiment of FIG. 11 .
DETAILED DESCRIPTION
As described above, traditional ICP ion sources typically produce an electrical field, due to the capacitance introduced due to the high voltages in the antennas 126 , 146 .
As shown in cross-section in FIG. 6 , the RF source 490 uses a mechanism, where a coil 410 is would around ferrite 400 , which is u-shaped in this instance. The ferrite 400 has a main body 420 , around which the coil 410 is wound, and two legs 430 extending perpendicularly from the ends of the main body 420 . An alternating current is passed through the coil 410 , which may be an insulated wire in one instance. The current in the coil 410 creates a magnetic field in the ferrite 400 . This alternating current has a frequency, such as between 50 kHz and 50 MHz. The magnitude of the current may vary, based on the amount of power that is dedicated to creating this field. In addition, the strength of the magnetic field is also a function of the spacing between the legs 430 , and this parameter affects the amount of power required to create the desired magnetic field.
The ferrite can be constructed from various materials. In some embodiments, the choice of material is related to the frequency of the alternating current. For example, manganese zinc ferrites are preferably used for frequencies up to 500 kHz, while nickel zinc ferrites can be used for higher frequencies.
Most of the magnetic field created by the current passing through the coil 420 is captured by the ferrite 400 . The magnetic field lines 440 close near the distal ends of the legs 430 of the ferrite 400 , thereby creating a localized magnetic field with little to no electrical field.
The RF source can be positioned on a surface in several different ways. As shown in FIG. 6 , the RF source 490 may be placed on a dielectric window 470 such that the distal ends of the legs 430 are in contact with the dielectric window 470 . Materials such as quartz and alumina may be used for this dielectric window 470 . In this embodiment, the magnetic field 440 may not extend significantly into the chamber, which is located on the opposite side of the dielectric window 470 .
In another embodiment, shown in FIG. 7A , the distal ends of the legs 430 of the ferrite 400 extend beyond the wall 472 . Wall 472 does not need to be dielectric in this embodiment, since the magnetic field is generated on the opposite side of the wall 472 , within the plasma processing chamber. In fact, wall 472 may be any material, including a dielectric material or a metal, such as aluminum. In this embodiment, because of the location of the distal ends of the legs 430 , the magnetic field 440 extends further within the chamber formed by the wall 472 . The ferrite extensions 435 can be created in several ways. In one embodiment, the wall 472 is cut out, such that the distal ends of legs 430 of the ferrite 400 are placed in the cut out portions and extend through these cutouts. In this embodiment, the leg extensions 435 are preferably bonded to the wall 472 , preferably in an airtight manner. Various glues or seals, such as o-rings, may be used to create this bond. The introduction of the leg extensions 435 into the chamber may be a source of particulates. In some embodiments, the legs 430 , and specifically the leg extensions 435 , are coated with silicon to minimize the amount of contamination introduced to the chamber.
In another embodiment, shown in FIG. 7B , the legs 430 of the ferrite 400 sit on the dielectric window 470 . Separate ferrite extensions 436 may be added inside the chamber formed by the dielectric window 470 , opposite each of the distal ends of the legs 430 to extend the magnetic channel inside the chamber. As described above, these separate ferrite extensions 436 may be coated with silicon to minimize contamination.
This RF source 490 can be formed in a variety of shapes and sizes. In some embodiments, the legs 430 are sufficiently long so that the electric field surrounding the coil 420 does not reach the window 470 . The width of the main body 410 , which determines the spacing between the legs 430 may be varied. In embodiments where the legs are spaced relatively close together, the magnetic field density is high, however it is also highly localized. In contrast, where the legs 430 are spaced apart, the magnetic density decreases, but the magnetic field is more distributed. Therefore, there is a tradeoff between power supplied to the coil 420 , the spacing between the legs 430 , and the uniformity and density of the magnetic field 440 created.
In one embodiment, the top view of which is shown in FIG. 8 , the ferrite 400 is semi-circular. This shape may be used in conjunction with a plasma processing chamber 104 , such as the one shown in FIG. 1 . In this embodiment, the ferrite may be semi-circular, with coils 450 that also follow a semi-circular path, approximately parallel to the legs. The legs (not shown) extend downward from inner edge 460 and outer edge 461 . This configuration creates a semi-circular annular magnetic field, where the field is located between the legs extending downward from edges 460 , 461 . While a semi-circular ferrite 400 is shown, other shapes are possible, such as quarter circles, semi-oval and others.
As the RF source 490 of FIG. 8 only creates a semi-circular annular magnetic field, in some embodiments, two such ferrites may be arranged to form a complete circle, as shown in FIG. 9 . In this embodiment, two identical RF sources 490 a , 490 b are arranged in a circular pattern so as to create an annular magnetic field. In some embodiments, these RF sources 490 a , 490 b are placed atop a dielectric window 470 , such that the magnetic field permeates the dielectric window 470 and the chamber (as shown in FIG. 6 ). In other embodiments, the legs of the RF sources 490 a , 490 b extend into the chamber, as shown in FIG. 7A . In other embodiments, ferrite extensions are disposed on the dielectric window 470 in the chamber, opposite the distal ends of the legs.
In some embodiments, the discontinuities in the magnetic field between RF sources 490 a , 490 b may be undesirable, and may cause plasma non-uniformity. In such embodiments, third and fourth smaller RF sources 491 a , 491 b may be inserted within the circle created by RF sources 490 a , 490 b , as shown in FIG. 9 . These RF sources 491 a , 491 b are preferably concentric with RF sources 490 a , 490 b and are arranged so that the openings between them are rotated a quarter turn from the openings between RF sources 490 a , 490 b . As described above, these RF sources 490 , 491 may sit atop a dielectric window 470 , as shown in FIG. 6 , or may extend into the plasma processing chamber, as shown in FIG. 7 . Of course, other variations, dimensions, or rotations than that illustrated in FIG. 9 are possible.
FIG. 10 shows the RF sources 490 of FIG. 9 used in conjunction with a plasma processing chamber 500 . As described in conjunction with FIG. 1 , the plasma processing chamber 500 has a gas inlet 510 , a baffle 170 , a platen 134 , and an exhaust port 110 . In one embodiment, the RF sources 400 may be disposed on dielectric windows 520 . The dielectric windows 520 may extend along a vertical direction at an oblique angle relative to the chamber walls 521 , as shown in FIG. 10 . In other embodiments, the dielectric windows 520 may be perpendicular to the chamber walls 521 .
In another embodiment, the legs 430 of the ferrites may extend through the windows 520 into the chamber 500 . In this embodiment, the windows 520 need not be constructed of dielectric material. Although the windows 520 are shown as slanted, other embodiments are possible. For example, in another embodiment, the RF sources 490 may replace the antennas 126 , 146 shown in FIG. 1 .
FIG. 11 shows a top view of a second embodiment of the RF source 690 . In this embodiment, the main body 620 of the ferrite 600 is straight, rather than semi-circular. Coils 610 are wound around the main body 620 . The main body 620 has two edges 601 , 602 , which are approximately parallel to the path of the coils 610 . The legs (not shown) extend downward from these edges 601 , 602 .
FIG. 12 shows a perspective view of an ion source, such as that shown in FIGS. 5A-B , being used in conjunction with RF source 690 . In this embodiment, the RF source 690 is placed on a dielectric window 650 on the side of the rectangular enclosure 302 directly opposite extraction slit 335 . The ferrite 600 may be roughly the same length as the rectangular enclosure 302 . Since the magnetic field created between legs 430 is uniform along the length of the main body 620 , the resulting plasma density within the rectangular enclosure 302 should likewise be uniform across the length of the enclosure 302 . In another embodiment, the ferrite 600 may be positioned such that the legs 430 extend into the rectangular enclosure 302 , as shown in FIG. 7A . In this embodiment, the top surface 650 does not need to be a dielectric material. In another embodiment, ferrite extensions are used to extend the ferrite legs into the chamber, as shown in FIG. 7B . In this embodiment, the top surface is a dielectric material.
The present disclosure is not to be limited in scope by the specific embodiments described herein. Indeed, other various embodiments of and modifications to the present disclosure, in addition to those described herein, will be apparent to those of ordinary skill in the art from the foregoing description and accompanying drawings. Thus, such other embodiments and modifications are intended to fall within the scope of the present disclosure. Further, although the present disclosure has been described herein in the context of a particular implementation in a particular environment for a particular purpose, those of ordinary skill in the art will recognize that its usefulness is not limited thereto and that the present disclosure may be beneficially implemented in any number of environments for any number of purposes. Accordingly, the claims set forth below should be construed in view of the full breadth and spirit of the present disclosure as described herein. | A RF source and method are disclosed which inductively create a plasma within an enclosure without an electric field or with a significantly decreased creation of an electric field. A ferrite material with an insulated wire wrapped around its body is used to efficiently channel the magnetic field through the legs of the ferrite. This magnetic field, which flows between the legs of the ferrite can then be used to create and maintain a plasma. In one embodiment, these legs rest on a dielectric window, such that the magnetic field passes into the chamber. In another embodiment, the legs of the ferrite extend into the processing chamber, thereby further extending the magnetic field into the chamber. This ferrite can be used in conjunction with a PLAD chamber, or an ion source for a traditional beam line ion implantation system. | 7 |
[0001] This application is related to co-owned co-pending application Ser. No. ______ filed Nov. 8, 2000, entitled “Method and Apparatus for Extending PBX Features via the Public Network”, the complete disclosure of which is hereby incorporated herein by reference.
[0002] This application is further related to co-owned co-pending application Ser. No. ______, filed ______, entitled “Priority Based Methods And Apparatus For Transmitting Accurate Location identification Numbers (LINs) From Behind A Multiline Telephone System (MLTS)”; co-owned co-pending application Ser. No. ______, filed ______, entitled “Methods And Apparatus For Transmitting Accurate Location Identification Numbers (LINs) From Behind A Multiline Telephone System (MLTS) Utilizing Port Equipment Numbers”; co-owned co-pending application Ser. No. ______, filed ______, entitled “Methods And Apparatus For Transmitting Accurate Location Identification Numbers (LINs) From Behind A Multi-Line telephone System (MLTS) After An Emergency Caller Disconnects”; co-owned co-pending application Ser. No. _______, filed ______, entitled “Methods And Apparatus For Transmitting Accurate Location Identification Numbers (LINs) After An Emergency Caller Disconnects”; and co-owned co-pending application Ser. No. ______, filed ______, entitled “Methods And Apparatus For Dialing An Emergency Telephone Number From A Teleworking Client Remotely Coupled To A PBX”, the complete disclosures of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates to methods and apparatus for dialing an emergency telephone number from a teleworking client remotely coupled to a PBX. More particularly, the invention relates to methods and apparatus for intercepting dialed digits (e.g., TAPI messages, DTMF tones) dialed by the teleworking client, uncoupling the teleworking client from the PBX, coupling the teleworking client to the PSTN, and transmitting the digits as DTMF tones over the PSTN.
[0005] 2. Brief Description of the Prior Art
[0006] People can access a wide variety of services and functions through telecommunications systems. A subscriber can receive, send, and forward voice messages, faxes, e-mail, and data, and can remotely manage many business and personal functions.
[0007] This new technology has important implications for teleworking. In teleworking, a teleworker performs work functions from a remote location. In many cases, a teleworker can perform functions identical to those performed by her colleague in the office. Teleworking can be loosely defined as workers performing work functions remotely through a telecommunications system.
[0008] Teleworking offers workers unprecedented flexibility and convenience for workers. It also provides opportunities for people who have traditionally been excluded from the work force or who have been able to participate on a limited basis only. It can remove geographical barriers, better integrate the disabled into the work force, and provide retraining and rehabilitation programs for the institutionalized.
[0009] Most advanced features are implemented and controlled through a control channel, which requires the user to have a telephone system, typically ISDN, that provides a separate channel for the control signal. Unfortunately, many subscribers do not have ISDN telephones or ISDN lines. ISDN telephones and lines are particularly rare in private homes, locations where teleworking can make the biggest difference. What is needed is a better way to integrate ordinary subscribers into teleworking.
[0010] The above referenced previously incorporated application entiled “Method and Apparatus for Extending PBX Features via the Public Network”, discloses a system and method for allowing clients with a variety of teleworking devices, including digital and/or non-specialized dual-tone multi frequency (DTMF) telephones, to invoke PBX (private branch exchange) features. The user can invoke all or, alternatively, major PBX functions from any location.
[0011] In a preferred embodiment of the application referenced in the previous paragraph, a mobility circuit board system (IGate, SMPLX, WAML) includes a set of ports, called (herein) fictitious ports, that are not dedicated to fixed branch extensions. A fictitious port on a mobility board is assigned to a teleworker. The circuit board is responsible for enabling a teleworker at a remote phone to be treated by the switch as if he were connected to a standard physical port of the switch. When a teleworker logs in, he is assigned a fictitious port, which supports access to PBX functions.
[0012] After logging in, the teleworker can input digits to access PBX features (via feature code) or digits to call an inside or outside party via routing through the PBX. The digits are sent to the teleworking server (TW server, TWS). If a feature code is recognized by the server, the digits are suppressed from reaching the other party, and the teleworking server invokes the requested feature and sends the proper signals to the switch. The system thus provides the teleworker PBX functions at any location. In alternatives, an interactive voice recognition (IVR) system with prompts can be used to signal selection of PBX features.
[0013] Among other features, the system and method also provide for identification and call-back to avoid toll charges; activation and deactivation of call redirection; entering new call redirection destinations; identification of call redirection phone numbers; receiving and making both business and personal calls; activation and deactivation of voicemail and fax mail notifications; locating the teleworker; and dialing into specific numbers that activate and/or deactivate teleworking features without requiring user input and without requiring the call to be answered.
[0014] A method 300 for logging in is illustrated in FIG. 4. At step 302 , the teleworking client calls the system. (In alternatives, the system places a call to the teleworking client.) At step 304 , the teleworking client logs in, including an optional sub-step 306 , at which the calling line is identified, and an optional sub-step 308 , at which the teleworking client enters a PIN. Neither step, either step, or both steps can be implemented as part of login. Furthermore, other identifiers such as voice recognition can be added or used as alternatives.
[0015] At step 310 , the teleworking server (TWS) checks the login. If the login is not approved, the method loops back to step 304 . As indicated by optional step 312 , the number of attempts can be regulated by an attempt counter or a timeout timer. If the process times out, the method ends, at a step 314 .
[0016] If the login is approved, the method continues to step 316 , and the IGate assigns a fictitious port to the user. At a step 318 , the TWS assigns the teleworking client's office extension to the fictitious port. An optional step 320 makes a subset of PBX features available to the fictitious port; alternatively, the full set of features is available. At a step 322 , the PBX features can be accessed at the teleworking client's remote site, the site from which the original call was placed.
[0017] One unusual problem arises when a teleworking client is coupled to a remote PBX/MLTS (multiline telephone system) and the teleworking client calls an emergency telephone number. In the U.S., the number 911 is designated as an emergency number through which police, fire, and medical emergencies may be reported.
[0018] Normally, when a caller dials 911, the call is directed to a public safety answering point (PSAP) with a Caller ID (i.e., a subscriber line e.g., analog, BRI or Calling Party Number (CPN/ANI) (i.e., PRI or CAMA trunk). When the Caller ID is on a device behind a PBX/MLTS, an emergency location identification number (ELIN as defined by the National Emergency Number Association), in addition to the caller ID, is currently required by some legislative bodies to be transmitted from the caller's PBX/MLTS to the central office and the PSAP. The ELIN represents (i.e., indicates a 10-digit NANP number) the location of the caller, e.g. street address.
[0019] When a teleworking client calls 911, the call is handled by the PBX/MLTS as if the caller were located at the same location as the PBX/MLTS. Thus, incorrect ELIN and caller ID information are transmitted to the PSAP. Moreover, the call may not even be directed to the correct PSAP as the teleworking client and the PBX/MLTS may be located in different PSAP jurisdictions e.g., cities or even different states.
SUMMARY OF THE INVENTION
[0020] It is therefore an object of the invention to provide methods and apparatus for dialing an emergency telephone number from a teleworking client.
[0021] It is also an object of the invention to provide methods and apparatus for intercepting “emergency” digits dialed by the teleworking client, uncoupling the teleworking client from the PBX/MLTS, coupling the teleworking client to the PSTN, and transmitting the emergency digits over the PSTN.
[0022] It is another object of the invention to provide methods and apparatus for maintaining a database of emergency numbers to be intercepted.
[0023] In accord with these objects which will be discussed in detail below, the methods according to the invention include detecting at the teleworking client when an emergency number is dialed, disconnecting the teleworking client from the PBX/MLTS, connecting the teleworking client to the PSTN, and dialing a stored number associated with that number which was dialed. The apparatus of the invention resides in software that is installed in off the shelf hardware. Though the invention is described with reference to a teleworking client, it may also be applied to any other dialup network connection. The emergency digits (dialed and subsequently signalled to the PSTN) are not limited to emergency numbers, but are determined by the TW client via administration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a high level schematic diagram of a system according to the invention;
[0025] [0025]FIG. 2 is a high level block diagram of teleworking client software according to the invention;
[0026] [0026]FIG. 3 is a simplified flow chart illustrating the methods of the invention; and
[0027] [0027]FIG. 4 is a simplified flow chart illustrating co-owned related technology.
DETAILED DESCRIPTION
[0028] Turning now to FIG. 1, a system according to the invention includes a PBX/MLTS 10 coupled to local phone sets 12 and a local area network (LAN) 14 servicing multimedia PCs 16 , a teleworking server 18 , a data server 20 , and a security server 22 . The PBX/MLTS 10 is coupled to the PSTN (public switched telephone network) 28 via a gateway 24 and an access server 26 .
[0029] According to the system of the invention, remote teleworking clients 30 , 34 access the PBX/MLTS 10 and the LAN 14 via the PSTN 28 . Teleworking clients may include separate telephones 30 and PCs (hybrid clients) or may include a multimedia IP client 34 . According to the invention specialized software, described below with reference to FIGS. 2 and 3, supports the teleworking client.
[0030] According to the invention, a hybrid client 30 , 32 uses two links to the PBX/MLTS 10 : one for voice information and one for multiplexed data and signaling information. The two links could be provided by an ISDN basic rate interface (BRI) or two analog dialup connections or any means of data connectivity (e.g., T3, T1, DSL, cable modem). Depending on the different link types the following clients can be differentiated.
[0031] A teleworking IP client 34 according to the invention preferably includes a standard off the shelf PC so long as it is able to support IP based protocols (e.g., H.323, SIP, etc.) for voice and Multi Media data and signaling information data streams via an appropriate network interface (excluding IP only phone Client).
[0032] Turning now to FIG. 2, an example of teleworking client software 40 according to the invention includes a user interface 42 through which a user gains access to applications 44 . The applications 44 communicate with a session manager 52 via a plurality of application programming interfaces (APIs) 46 , 48 , 50 . The session manager 52 communicates with the PSTN via the call service manager 54 and with the teleworking A/V hardware via the media service manager 56 (both shown included, along with emergency caller module 58 , as part of client software 53 depicted in FIG. 3).
[0033] More particularly, the call service manager 54 communicates with the network via a call control module 60 through a LAN connection 66 . According to the invention, an emergency caller module 58 , described in more detail below with reference to FIG. 3, monitors network traffic for a defined sequence of dialed digits. The media service manager 56 communicates with various terminal adapters 68 , 70 via service providers 62 , 64 .
[0034] According to the presently preferred embodiment, the emergency caller module 58 is associated with a database 72 of emergency numbers. The database 72 is provided with an administration interface 74 through which the teleworking user may enter/edit numbers that will be intercepted by the emergency caller module 58 . According to an optional feature of the invention, the database and administration may be configured such that an intercepted number is associated with another number that will be dialed via the PSTN.
[0035] For example, if a teleworking user is connected to the PBX/MLTS via another PBX, e.g. in a hotel that provides a separate data connection, which requires that the user dial a digit, e.g. 9 , to be connected to an outside line, the software can be programmed to insert the extra digit before dialing the emergency number. According to a further preferred embodiment, the emergency caller module 58 monitors dialed digits when a teleworking session is active and a new call has been placed.
[0036] [0036]FIG. 3 depicts the high-level processing of the invention that begins when the teleworking client has logged on and has an active session as illustrated at 100 . Monitoring for digits dialed by the teleworking client user begins at 102 . When a dialed digit is detected, a digit pattern matching function is performed at 104 . If it is determined at 106 , that the digits do not match a number in the database of emergency numbers, the software returns at 108 to monitor digits for the next call.
[0037] According to the presently preferred embodiment, the first digit is compared to the first digit of the associated pre-defined database of emergency numbers. If no match is found, the search is ended with no match. If a match is found, the second digit is collected and compared to the second digit of the associated pre-defined table of emergency numbers for those numbers which matched on the first digit. If no match is found, the search is ended with no match. If a match was found, the third digit is collected and compared to the third digit of the associated pre-defined table of emergency numbers for those numbers which matched on the first and second digit.
[0038] This process continues until either no match is determined or the digit string match is found at 106 . Though not shown in FIG. 3, when a match is found, the database entry corresponding to the dialed emergency number is remembered for use in dialing over the PSTN.
[0039] If a match is found, the teleworking session is immediately disconnected at 110 (i.e., logged off, link dropped). An on-hook event is sent to the public network followed by an off-hook event at 112 . When dial tone is received (i.e., from public network) at 114 , the indicated number in the database (plus any programmed prefix) is automatically “outpulsed” on behalf of the teleworking user at 116 . The emergency call monitoring is then stopped at 118 . A normal public network call is in progress (i.e., no teleworking session). It is routed correctly to the proper PSAP with the correct call information (i.e., calling directory number).
[0040] There have been described and illustrated herein methods and apparatus for dialing an emergency number from a client coupled to a remote network via the PSTN. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope as so claimed. | Systems for dialing an emergency telephone number from a teleworking client according to the invention include apparatus that implement the steps of detecting at a teleworking client when an emergency number is dialed, disconnecting the teleworking client from the PBX/MLTS, connecting the teleworking client to the PSTN, and dialing an associated stored number. Though the invention is described with reference to a teleworking client, it may also be applied to any other dialup network connection. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a divisional of U.S. patent application Ser. No. 10/207,685 “INTERACTIVE ONE TO MANY COMMUNICATION IN A COOPERATING COMMUNITY OF USERS” filed Jul. 26, 2002 and assigned to IBM. The disclosure of the forgoing application is incorporated herein by reference.
COPYRIGHT NOTICE
[0002] 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 and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
[0003] The present invention is related to systems and methods for distributing data, more particularly to systems and methods for distributed computer users to enter into a two way electronic conversations using Publication/Subscription services.
BACKGROUND OF THE INVENTION
[0004] There are several ways that a requester can solicit help from a group of listeners today. He could use e-mail to send a request to a predetermined group of listeners who could each make a decision whether to engage in e-mail conversation with the requester. The problem is that e-mail's persist and have an indeterminate turn around, thus a listener may happen to see the requesters e-mail “immediately” but another listener may see the e-mail hours (or months) later. Conversing by e-mail would be very frustrating. The requester may enter a chat room to make his request, the problem is that all the members of the chat room are peers so it would be difficult to assure that listeners were interested enough to engage in conversation on a requesters subject and even if they were, the chat room would be cluttered with many users messages pertaining to many subjects all interspersed. The requester could open an instant message (IM) session with one listener at a time but he'd have to know which listener to direct the request to and wait a period for response to the listener to decide that the listener wasn't responding. Prior art methods often require the requester know the ID of the members of the community, know their interest and skills, share conversation with other requesters, take a long time to negotiate to find the appropriate listener, allow only one to one communication and the like.
[0005] FIG. 1 depicts the elements that make up a typical computer for use in networked applications. The computer 100 consists of a Base Computer 101 which comprises a processor 106 , storage media such as a magnetic disk 107 and a high speed volatile main memory 105 . An operating system and application programs 111 reside on the storage media 107 and are paged into main memory 105 as needed for computations performed by the processor 106 . The Base computer may include optional peripheral devices including a video display 102 , a printer or scanner 110 , a keyboard 104 , a pointing device (mouse) 103 and a connection 108 to a network 109 . In a client environment, a user will interact with a (Graphical User Interface) GUI by use of a keyboard 104 and mouse 103 in conjunction with the display of information on the display 102 under control of an application program (application 1) 112 . The client application program 112 will then interact with remote users by way of the network 109 .
[0006] In FIG. 2 an example Internet system is shown. A user at client 1 201 uses applications on his system. This user (user 1 210 ) at client 1 201 can interact with clients 2 - 4 202 - 204 by way of a client server computer 206 . Applications 112 may be provided by each client 201 - 205 and or the client server 206 or some remote server 208 by way of the network 207 . The user at client 1 201 can interact with a remote user (user 5 211 ) at client 5 205 by way of the Internet 207 .
[0007] Networked clients comprise applications for communication. E-mail applications provide for sending a message to a mail server that then makes the recipient aware of the waiting message. The recipient then can elect to open the message and view it at his client machine. E-mail messages can be sent to a single recipient or can contain a list of several recipients (one to many). One to many e-mail transactions are popular with advertisers and the use of one to many e-mails has been dubbed “SPAM-ing”. Recently Instant Messaging (IM) has gained popularity in the form of sending text messages directly to another client. A first user composes an IM and selects a second user as the target. A message is then sent directly to the second user and appears on his display as either a message or the notification of a message. IMs are typically one to one messages.
[0008] A pub/sub service 304 receives messages originating from a content service and delivers them to client subscribers. An example message published includes a topic string, a set of property name-value pairs, and a body. A subscriber identifies a topic string pattern and properties test, and receives matching messages according to a standard, for instance JAVA Message Service (JMS).
SUMMARY OF THE INVENTION
[0009] An IBM marketing representative is typing away at his THINKPAD in an Atlanta, Ga. hotel room. A software developer at the Santa Teresa, California Lab looks up at the clock—10 PM, only twelve hours away from product code freeze. A secretary in Somers, N.Y. is scrambling to decipher an obscure LOTUS Notes error message she received while accessing an executive's calendar.
[0010] What do these three employees have in common? They each open their Sametime Connect Instant Messaging “buddy lists” and click on the “SkillTap” Bot. A Bot is an automated assistant (robot). Bot active agents are discussed in U.S. patent application Ser. No. 10/002,685 “Accessing Information Using An Instant Messaging System” assigned to IBM and incorporated herein by reference. The SkillTap Bot can instantly deliver requests for help concurrently to an entire community of online employees. Immediately, coworkers who have elected to see SkillTap Instant Messages containing keywords of interest to them are presented an alert box with the message—they can quickly choose to respond if appropriate, or discard the alert if they are unable to deal with the request for any reason (no question asked . . . entirely anonymous so far and on a volunteer basis only).
[0011] An employee casually reading mail at home in Seattle, Wash. sees an alert pop-up on his screen from the marketing rep—“Customer in Atlanta requires immediate assistance with enabling SSL LDAP authentication under IHS/Websphere on Netfinity 4000/Linux”. The words “Websphere”, “Linux”, and “Atlanta” are highlighted in red, based on filtering rules the Seattle employee had defined. He clicks a button to initiate a Sametime Instant Message discussion with the customer rep. “Been there, done that”, “family in Atlanta area”, “help at the customer site Friday, stay the weekend with family, fly you back Monday” —solutions converge quickly. The marketing rep gets a good nights sleep. The responder gets a change of scenery, some customer experience, and moves up a notch on the “Top Guns” SkillTap Scoreboard. Life is good.
[0012] So, how does this thing work, you ask? From the “requester” side, you need nothing installed beyond the Sametime Connect Instant Message client, which most employees are already using for daily instant messaging communication with other employees. Using the “People” menu, select “Add . . .” and type in Sametime User name “skilltap@us.ibm.com” to add the SkillTap Bot to your buddy list. When you have an important problem that requires immediate assistance, simply click on the Bot and ask him your question. Be sure to include enough details in the message that only users filtering on the important keywords will receive the message (e.g. Java, Websphere, AIX, SP2, zSeries, LDAP, DB2, Domino, MQ, etc.). Also, be aware that this message is potentially being delivered to a large number of users, so remember to follow basic rules of etiquette. Finally, when you are really stuck, keep in mind that no question is too simple—just think of the SkillTap community as a large room of coworkers who have all indicated a willingness to help—so, go ahead, just ask!
[0013] To be able to see questions posted by other employees, and to actively participate as a “responder”, you must first download program applications to your PC. The applications are the Sash weblication called “Shotgun” and the “SkillTap” weblication, from the Web site. Next, refer to the Shotgun documentation to understand how the SkillTap application is enabled under the Shotgun client, and how to define “filters” to control which SkillTap instant messages you will receive. Once you have defined the filter words and expressions that are of interest to you (e.g. Java, Perl, Linux, AIX, zSeries, DB2, MQ, Lotus Notes, Power, wireless, etc.), just sit back and wait for coworkers to ask for your help.
[0014] Web Pub/Sub services provide for a single publisher to publish messages to large numbers of clients. The present invention (herein called “SkillTap”) utilizes Pub/Sub Applications to publish an Instant Message (IM) from a requester to subscribers of a Pub/Sub channel (listeners). The listeners, running a special SkillTap application, each receive the message as an IM. In one embodiment, the published message is displayed in a special SkillTap alert window. If a listener decides to engage in conversation with the requester, he responds to the IM. The requester receives IM's from each responder in separate windows and elects one responder to converse with at a time. When the conversation is over, the requester is optionally prompted for Frequently Asked Question (FAQ) database information and/or and evaluation of the session with the listener of the conversation. Message filters are employed to allow listeners to only be alerted to messages that contain content of interest. Message throttles are employed to limit number of listeners engaging the requester.
[0015] It is therefore an object of the invention to access a dynamic database in a cooperating community of anonymous users comprising the steps of retrieving a list of approved subscribers comprising a community of users; receiving a first message from a first user, the message directed to the community of users; querying a dynamic database according to text in the first message wherein the dynamic database is modifiable by members of the community of users; and transmitting a second message comprising results of the dynamic database query to the first user.
[0016] It is a further object of the invention to generate dynamic database elements (wherein the data base is optionally a FAQ data base) in a system for instant message using a pub/sub server comprising the steps of transmitting a request message for publication to the pub/sub server Receiving a response message from a first subscriber; Selecting a data base element generation GUI option; Editing the data base element generation GUI; and incorporating the edited database element in a data base available to subscribers.
[0017] It is a further object of the invention to provide a data base GUI that includes elements of the response message.
[0018] It is a further object of the invention to provide a data base GUI that automatically includes elements of the request message.
[0019] It is a another object of the invention to include options in a data base GUI for displaying a preexisting data base element.
[0020] The above as well as additional objectives, features, and advantages of the present invention will become apparent in the following written description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a diagram depicting a prior art computer;
[0022] FIG. 2 is a diagram of user computers interconnected in an Internet network;
[0023] FIG. 3 is a logical depiction of a Pub/Sub implementation;
[0024] FIG. 4 is a logical depiction of a messaging system of the present invention;
[0025] FIG. 5 is a GUI view of an IM window employing the invention;
[0026] FIG. 6 is a requester's IM window for broadcasting;
[0027] FIG. 7 is a requester's IM window with a listener's response;
[0028] FIG. 8 is a listener's IM filter creation window;
[0029] FIG. 9 is a listener's alert window highlighted according to his filter.
[0030] FIG. 10 is a listener's window comprising the initial request;
[0031] FIG. 11 is a listener's Im window comprising the listener's response text;
[0032] FIG. 12 is the requester's IM window opened by the listener's first response;
[0033] FIG. 13 is the requester's IM window including a reply to the listener's message;
[0034] FIG. 14 is the IM window comprising the session communication;
[0035] FIG. 15 is an optional requester window opened at conclusion of a session;
[0036] FIG. 16 is a requester window for creating a FAQ;
[0037] FIG. 17 is an automated message requesting a value rating from the requester;
[0038] FIG. 18 is a flowchart of the events of an embodiment of the invention;
[0039] FIG. 19 is a flowchart depicting function of the invention;
[0040] FIG. 20 is a flowchart expanding a setup scenario;
[0041] FIG. 21 is a flowchart expanding initiating a message to skilltap;
[0042] FIG. 22 is a flowchart expanding receiving an initiating message;
[0043] FIG. 23 is a flowchart expanding displaying an initiating message;
[0044] FIG. 24 is a flowchart expanding responding to an initiating message;
[0045] FIG. 25 is a flowchart expanding receiving response message; and
[0046] FIG. 26 is a flowchart expanding post correspondence options.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] The present invention provides a method for one to many communication preferably by way of Instant Messaging technology. It utilizes a novel combination of Pub/Sub service which publishes a service to subscribers wherein the subscribers elect a service channel and message filtering in order to customize the type of information presented to the subscriber. The novel combination is described in US Patent Application Docket Number POU920020088US1 “INTERACTIVE FILTERING ELECTRONIC MESSAGES RECEIVED FROM A PUBLICATION/SUBSCRIPTION SERVICE” assigned to IBM and incorporated herein by reference.
[0048] Refer to FIG. 3 . The pub/sub system is made up of a Content Provider application (Service) 301 - 303 , the Subscriber (Client) 305 - 306 , and the Pub-Sub Service 304 . Applications may implement one or more of these roles. The content provider 301 - 303 generates content for distribution through the pub/sub system 300 . Content providers 301 - 303 send structured content to one or more instances of the pub/sub service 304 . The subscriber 305 - 306 sends subscription requests 307 to an instance of the pub/sub service 304 and, subject to acceptance of a particular subscription request, receives content 308 from the pub/sub service. The actual content received will be determined by the subscription and the message selection process.
[0049] The pub/sub service 304 acts as both a subscription manager 310 and a content distribution agent 311 . Applications implementing the pub/sub service role 304 accept subscription requests 307 from subscribers 305 and, subject to any applicable authentication or access control policies, accept or reject subscription requests; and distribute content 308 to valid subscribers 305 .
[0050] The actual content sent to each subscriber 305 - 306 by the pub-sub service 304 will be determined by the subscription process 310 and through the message selection process 311 .
[0051] Applications implementing some aspect of the pub/sub system may act in different roles in different circumstances. For example, an application implementing the pub/sub service role 304 may itself act as a subscriber, subscribing to and receiving content from another instance of the pub-sub service. Similarly, an application acting in the subscriber role may act as a content producer if the end-user of the application wishes to publish a message to the service.
[0052] The pub/sub system provides for communication among applications implementing the application roles. There are two primary communications in the pub/sub system: messages are sent from content providers to pub/sub services; and pub/sub services send messages to subscribers 308 , 312 .
[0053] Content providers 301 - 303 may generate messages from any content source, and subscribers may dispose of messages in any manner they choose. For example, a content provider may simply be a gateway between a raw content source, such as e-mail or web pages, to the pub-sub service. Similarly, a subscriber 305 , 306 may act as a gateway between the pub-sub service and an external service such as NNTP or e-mail.
[0054] FIG. 4 depicts a logical representation of components of the present invention. The system enables a client to send an IM to an automated client (Bot). Bots used to present an interface to program applications are described in U.S. patent application Ser. No. 10/002,685 “Accessing Information Using An Instant Messaging System” assigned to IBM and incorporated herein by reference. The client Bot re-sends the message to many listeners. The listeners each receive a special IM window. When a listener responds to the requester using his special window for the transaction, a new special IM window is presented to the requester. This completes the one to one IM connection between the requester and one of the listeners. The requester elects to commence conversation with a responding listener by using the Im window assigned to that listener's response. Other embodiments enable window sharing for multiple listeners responding to the same request or prompt the requester in a single GUI displaying listeners responding to a request in order that the requester can elect to open windows associated with the responding listeners.
[0055] More specifically, Clients 305 - 306 have downloaded App 1 ( 321 ) and App 2 ( 323 ) which enable message filtering 420 for message published 311 by a Pub/Sub service 304 . One component of Service A ( 301 ) includes an automated IM user (Bot) 402 which communicates to other applications 403 - 404 using IM technology. Service A ( 301 ) associates the Bot with a Pub/Sub channel. The Bot is represented to the community by an IM ID as if it were another user. Clients can be requesters or listeners or both. Requesters initiate requests to Service A's Bot exactly as in any IM initial event. Service A's Bot ID is associated with a Pub/Sub channel which has a plurality of subscriber clients (listeners). Listeners have subscribed to the Bot channel because they have common interests. The subscribers' IM ID's are preferably unknown to the requester. SkillTap associates subscribers with a channel by use of a table holding the information at the SkillTap server.
[0056] Service A's Bot ( 402 ) receives an IM from a requester's 305 IM session 403 and publishes it 311 to the active subscribers of the Pub/Sub channel associated with the Bot including client 2 ( 306 ). The requester's 305 IM window may then be closed. The Pub/Sub service 304 distributes messages to SkillTap applications running on client machines. One of these applications, App 2 provides filtering techniques on incoming messages to eliminate messages that are not of interest to the client 2 . App 2 ( 323 ) presents the request message to the listener user's display at client 2 ( 306 ). In one embodiment, the display at client 2 is like an IM display. If the listener is interested in responding, he transmits a response special IM by typing text in the displayed window. App 2 ( 323 ) uses IM 404 to transmit the message to the requester at client 1 ( 305 ). App 1 at client 1 ( 305 ) intercepts the response message and opens up a special IM window on the requester's display. This completes the negotiation from the requester for an IM session with a group of listeners. Communication between the two special IM windows continues until one window is closed.
[0057] It should be noted that in the preferred embodiment, the SkillTap client provides a “special IM” GUI that is used to provide the special SkillTap features. In the preferred embodiment, the initial request uses a standard IM GUI which is closed after transmitting the request. The requester receives responses from listeners in standard IM GUI. Thus a requester needs any IM service to initiate a SkillTap request and a special SkillTap IM application for the listening function. Another embodiment would provide all IM services in the special SkillTap IM application. These and other embodiments of the present invention could be created by one skilled in the art after learning the example embodiments herein.
EXAMPLE OF A PREFERRED EMBODIMENT
[0058] In the example that follows, Brian has installed an IM (instant messaging) application on his PC. He adds a user name “SkillTap@us.ibm.com” to his IM buddy list. In this case, SkillTap is not the name of a person, it is the name of an automated user robot (Bot) that receives and sends IMs as if it were any other user. The Bot also communicates with a Pub/Sub service as a content provider. Brian sends a request to “listeners” for information. Brian doesn't know who is listening specifically but he does know that they subscribe to the SkillTap Service. Mike, a “listener” has downloaded an application called Shotgun. Shotgun in this case is an IBM SASH Weblication from an IBM Web site. Mike has also downloaded the SkillTap weblication. The SkillTap application is enabled under the Shotgun client. Mike uses Shotgun Documentation to understand how the SkillTap application works. Mike has defined Shotgun Filters for his SkillTap channel to limit messages to topics of his interest and expertise the Filters base their decision to present messages directed to SkillTap to listeners based on the content of the messages.
[0059] Shotgun receives IMs directed to predetermined services (SkillTap Bot in this case) and enables the service to publish messages via channels to subscribers (listeners in this case). Listeners may respond by returning an IM to the requester (Brian). The return messages opens an IM window on Brian's computer which initiates the IM conversation between Brian and Mike. In another embodiment, the return message opens a chat room and Brian selectively engages in IM conversations with multiple listeners via the chat room. The chat room enables multiple listeners to participate in the conversation, it allows multiple listeners to view the conversation between Brian and Mike or optionally only provides Brian with a single instance of an IM window to converse with multiple listeners wherein each listener only sees conversation directed to him. Many other window variations would be useful and become obvious in light of the present invention.
[0060] An embodiment is demonstrated in the following example. In FIG. 5 , Brian, a marketing rep clicks on the “SkillTap” Bot 504 in his Instant Messaging (IM) Sometime window 501 .
[0061] In the resulting IM window shown in FIG. 6 , Brian defines a problem 602 and sends 603 a request to the SkillTap Bot 601 for publication to a group of users currently running the Shotgun client. The SkillTap service application publishes (via a Pub/Sub service) Brian's message to a predefined group of active clients.
[0062] In FIG. 7 , the SkillTap service responds to Brian's request with an acknowledgment 704 that the request message 703 has been successfully delivered to the community of active listeners. SkillTap imitates a knowledgeable client in one embodiment by returning messages from a FAQ database using artificial intelligence querying known in the art. In another preferred embodiment, SkillTap returns procedural information or prompts such as instructions to close the present window.
[0063] In FIG. 8 , an example filter window 801 is shown. Shotgun users subscribing to the SkillTap service are permitted to define message content filters. The example filter 802 of FIG. 8 shows a boolean list of keywords or'd together. The boolean “OR” is depicted by “I”. The filter defines the user's areas of interest or expertise. In the example, the user has entered “Atlanta” because he is interested in what's happening in his hometown of Atlanta. When Brian sent his request, the words in his request would have to pass the listener's filter in order for the listener to see the request.
[0064] In FIG. 9 , if the request passes the filter test, a Shotgun notification 901 immediately appears on the listener's screen. In the example, the filter keywords 903 “Atlanta”, “Websphere” and “Linux” are highlighted in the message. The window in the preferred embodiment also identifies the SkillTap service 902 as the Channel and supplies radio buttons for actions to be taken. In the example, the listener is asked if he wants to “Handle” this request. If he hits the No radio button, the operation is aborted.
[0065] If the listener wants to proceed, he hits “Yes” and the window depicted in FIG. 10 is displayed. This window 1000 is similar to any IM window. In the preferred embodiment the window shows additional information about the requester 1002 , in this case Brian's name, occupation, phone number and a hyperlink for more information about Brian. The information having been retrieved from data bases or subscription information. The listener is presented with the request message in the top field and in a second field is provided a place to type his response. His response includes text only or in another embodiment, the listener provides a link to image, audio or video information or any other media known in the art. Once the listener has typed his response he hits the “Send” UI (User Interface) button.
[0066] FIG. 11 shows the listener's window after he has entered his response 1101 .
[0067] FIG. 12 shows Brian's window after receiving one response. Note that in a preferred embodiment, Brian is reminded by SkillTap of his original request and that the IM transactions relate to that request. If Brian wanted to begin a new request, a new set of windows would be created and each one would remind Brian of the topic of his request. Part of the SkillTap service function is to provide an indication of the value of the responding listener's credentials. In the embodiment shown, the SkillTap application has asked past requesters to rate responding listener's on a 1-5 basis. The responder “Mike Van Der Meulen” in the example currently has an accumulated rating value of 4.3. The responses from Listeners open normal IM windows at the requesters' terminal, in this case IBM Sametime IM. In one embodiment, Brian elects to have one IM window displaying conversations related to his first request from multiple listeners. In a preferred embodiment, the SkillTap application allows Brian to use his mouse to drag a conversation window into another conversation window. The resulting new combination window displays messages from both listeners in a single window. Similarly, Brian uses his mouse to drag a user's message out of the window which creates a new conversation window for that conversation and optionally eliminates the dragged user from the original window.
[0068] In FIG. 13 , Brian continues the communication by entering his IM text directed to Mike. In another embodiment, continued negotiations via IMs are broadcast to all listeners.
[0069] FIG. 14 shows Brian's IM window after all negotiations with Mike have been completed. Brian closes this window to end communications.
[0070] FIG. 15 depicts a preferred embodiment of a method for the SkillTap service to assess the value of the responder's participation. In the example, a window appears when the conversation is closed. The window permits the requester to select from a list of predetermined categories. In the example, Brian selects “Assistance was provided*”. He also checks the “Add to FAQ” function.
[0071] In the next window of the example, FIG. 16 shows an embodiment of a FAQ creation window. In this embodiment, Brian is presented two fields, one containing text from Brian and the other containing text from Mike. Brian edits these windows (or in another embodiment, types into new windows) to create a brief paraphrase of the question and a brief paraphrase of the answer. In one embodiment of the present invention, Brian's value rating is increased by creating the FAQ. This is an incentive for Brian since his value rating will be seen when he is a responder listener to a request from another user.
[0072] FIG. 17 , shows SkillTap (an agent program Bot) asking Brian to rate Mike's response and explains the criteria. Mike's rating is provided to the SkillTap service and will be provided with Mike's response to future listening. In one embodiment, the value rating of listeners is used to prioritize responses from listeners.
[0073] In one embodiment, users can see their relative value rating by asking SkillTap for their standing. Mike, for instance could see that he is currently the 10th rated listener overall.
[0074] In another embodiment of the present invention, a SkillTap application optionally receives messages or publishes messages other than IMs. Messages can be transmitted/received using any media including for example: telephone, wireless, personal devices, voice to text, text to voice or automated applications. Messages can include attachments of image, audio, video, program applications, network invoking mechanisms (including hyperlinks, Web URLs) and the like.
[0075] In one embodiment, SkillTap comprises a throttling means to limit the number of messages. Responses to the requester are limited by any of a predetermined number of messages, a predetermined time window, a predetermined algorithm of priority (based on message content) or message sender's credentials and the like.
[0076] In another embodiment, SkillTap prioritizes publication of the request such that an initial publication goes to one set of listeners, a second publication goes to another set of listeners. The decision to publish to sets of listeners is either time based, response based, or explicitly requested by the requester.
[0077] In a preferred embodiment, SkillTap first sends the request to an active agent that queries a database for responses. The database is preferably a FAQ database but in another implementation, may be a query on cached responses accumulated from other SkillTap sessions.
[0078] In a preferred implementation, SkillTap requests include keywords to direct SkillTap action. A question to listeners uses “Ask”; a question to FAQ uses “FAQ”, an IM to SkillTap to set parameters or controls uses “PARM”. In another implementation, SkillTap interacts with the requester. For example, the requester submits a question using “Ask” and SkillTap responds with a list of groups for the request to be directed to such as “All”, “US”, “Japan”, “Hardware”, “Programmer”, “Marketing”, “FAQ”.. The requester responds with his selection and SkillTap then broadcasts the request to the selected group of listeners.
[0079] FIG. 18 depicts a flowchart of the SkillTap events. The requesters message is broadcast 1801 (published) to SkillTap client applications 1802 (listeners) that have subscribed to SkillTap. The SkillTap client application looks at the message and decides whether to present it to the user (listener). If the user decides to participate 1803 , he sends a response message. The SkillTap throttle controller 1804 checks to determine if the throttle threshold has been met using parameters in the database 1817 . If there aren't too many responders, interaction is enabled 1808 between the requester and responder(s). When the requester finishes his interaction 1809 , he is prompted for feedback 1810 about the value of the responder. If the requester elects 1811 to create a FAQ entry, he does so using the FAQ editor 1812 . When the FAQ is complete, it is submitted 1807 to the database 1815 .
[0080] FIG. 19 depicts the major events of setting up a skilltap channel, broadcasting a communication request via a pub/sub engine, engaging in communication with a subscriber to the skilltap channel and closing a communication session.
[0081] A User “A” wishes to participate in skilltap group communication. He downloads to his client a local skilltap application 1901 . He also downloads a shotgun application (may be part of the download of skilltap). Shotgun provides the GUI for subscribing to a channel of skilltap and for setting up message options such as filters, throttles and the like for skilltap messages. The Shotgun server maintains a list of subscribers for each channel. When a new subscriber joins the channel, he is authenticated and authorized and his network address is added to the list of approved subscriber for the channel (the channel's community of users). A user can use the GUI at any time to join or leave a Channel or alter his options. The user uses the GUI to get authorization to subscribe and/or publish for each channel. He is authenticated and approved based on credentials required by the specific implementation.
[0082] In FIG. 20 , User “A” interacts 1901 2001 with a web based subscription service (or alternatively, after downloading Skilltap, opens the Skilltap GUI and uses it) to subscribe 2001 to the remote skilltap service 2005 . The remote service in one embodiment saves information about User “A” during the subscription process. Such information as the user's network address/ID, contact information (telephone number, email . . . ), nickname, password, and preferences. Preferences include such things as: whether the user wants to be anonymous in transactions with other users in a skilltap session. Anonymity is maintained by skilltap by acting as a forwarding address for communication where skilltap supplies a temporary address/ID for others to use in communication with user “A”; Alternate ID's, where User “A” wishes to provide more than one network address/ID, and Distribution lists for SkillTap to forward messages to others to allow others to participate in the communication session or alternatively, for SkillTap to provide temporary subscription to a group so that the user can provide an adjunct list of group members. The user downloads a local skilltap application 2002 to his client if he hasn't already.
[0083] The local skilltap application is personalized 2003 with information 2006 useful for communications sessions. Information includes identifying information such as User “A”s Name, nickname, phone number(s), Fax number(s), Job Title, Expertise and the like. Local Skilltap also records the user's preferences for SkillTap such as if he wants anonymity or warning if he is about to break anonymity, his alias name, whether he wants to invoke a FAQ active agent robot as one of the recipients of his messages, default global filters for incoming messages, optional filters which can be invoked by a skilltap GUI may be nicknamed so the user associate their function easily. The Skilltap GUI settings identify whether the user wants to be alerted to incoming messages, whether he wants prompts and whether he wants a help function. The user then closes his setup GUI window 2004 and he is ready to go. In the preferred embodiment, anyone who wants to participate in SkillTap must download skilltap and perform the setup for their client. In another embodiment, Skilltap at the remote server, performs subscription and publishes IMs to subscribers who use standard IM applications to respond. The response IM is sent to the skilltap service as if it were the requester. The requester opens and closes an IM session with SkillTap as in other embodiments but in this embodiment, SkillTap service opens a second standard IM session to subscribers who respond in the second IM session. SkillTap then opens a third standard IM session with the initiator as a surrogate for the responder. The Skilltap service forwards the IM to the requester on behalf of the user. Thus, no local copy of skilltap is required.
[0084] When User “A” wishes to initiate a conversation FIG. 21 with subscribers 1902 (send a request message: “Ask . . .”), he does so by sending a standard IM message 2105 to a Bot “SkillTap@xxx.com”. The IM message is sent to an active agent in the SkillTap service via IM 2104 . In another embodiment, the user can elect 2103 to have SkillTap provide a special GUI for IMs 2103 . The special GUI provides IM services and SkillTap options.. The options include Help, invoking a temporary chat room, prompting the initiator for such things as Topic of conversation, Filters and Throttles for response messages, Keyword prompts for special functions (Ask . . . ) also media options such as invoking a translator to allow IMs to translate to/from phones, Voice <-> Text; email, mechanical controls for automation of machines and any media available to one skilled in the art.
[0085] Referring to FIG. 22 , the SkillTap service (Remote SkillTap App) receives the IM message “A” from User “A” 1903 2201 and evaluates the message 2202 . SkillTap decides 2203 to either publish 2206 the message 2204 or not 2205 . SkillTap retrieves the list of approved subscribers assigned to a channel which list includes the network address for the subscribers. Skilltap will publish IM message “A” to the addresses on the list. In one embodiment 2204 , SkillTap publishes to a subscriber group or elects to create a Chat Room such that the User ‘A’ conversation can be joined by more than one Subscriber. Some IM messages to SkillTap 2205 may not be published but used by IM to converse with User “A”. These IM conversations support such things as SkillTap Prompts for such things as how-to, SkillTap FAQ access, Help support, SkillTap Web masters, customizing of local SkillTap applications and plug-in requests. When IM message “A” is published to subscribers 2206 , User “A” closes his IM session and waits for responders to initiate SkillTap IM sessions.
[0086] Subscriber “B” is one of the subscribers to the SkillTap channel User “A” is using. Subscriber “B” has setup his local SkillTap application (as described for User “A” 0 1901 ) to Filter incoming messages, Throttle the incoming message activity and setup preferences for incoming communication. As part of the setup Subscriber “B” can elect to be warned of incoming messages by enabling 2208 an alert mechanism. In one embodiment, Alert options 2209 include whether the alert is an audible signal, a visual signal or a displayed icon.
[0087] When the Standard IM message “A” is published to Subscriber “B”, the Local SkillTap application 1905 alerts 2210 him of the incoming message. The Alert in one embodiment is includes electing to display information about User “A”, a Topic, or the full text message. A second alert in the embodiment (not shown) allows the user to elect whether or not to display other media such as a Browser URL site.
[0088] In FIG. 23 , if the subscriber elects to display options (from the alert icon) 1906 2301 , a GUI allow him to optionally select 2302 being prompted for display of the IM text, IM attachments (i.e., Text Files, Images, Audio, Video, Text <-> Voice . . . He can elect to display the IM messages, Display User “A” information (Name, title, job), or display of the IM text, IM attachments (i.e., Text Files, Images, Audio, Video, Text <-> Voice . . . Using the options, the Subscriber displays 2303 the incoming IM message “A” 1908 2304 in a Special SkillTap IM GUI window.
[0089] Subscriber “B” wishes to respond 1909 (join a conversation with User “A”) FIG. 24 , he types a response text and optionally attaches other media into the special GUI. The special GUI in a preferred embodiment appends the original message to the text and identifying information about the Subscriber (Name, Phone, Title . . . ) 2401 . In one embodiment, the Subscriber elects 2402 to add a group distribution list to copy messages 2404 to other IM users for this conversation. In another embodiment, the Subscriber invokes a temporary Chat Room function for the conversation by way of his local SkillTap application. The subscriber's response is transmitted to User “A” 1910 2405 .
[0090] In FIG. 25 1911 , the response IM message “B” from Subscriber “B” SkillTap IM message “B” is operated on 2501 by Content Filters, Throttling techniques, User preferences and message priority. The preferences 2502 include customizing the special incoming alert message GUI and display options. Based on the options, a local SkillTap application presents an alert of an incoming SkillTap response IM 2503 . If the User “A” elects to display the response skilltap IM message “B” and join the conversation with Subscriber “B” 1913 , the one to one special IM conversation is begun 1912 . During the conversation, the original IM is appended. If User “A” wishes to start a new session, he issues a standard IM to the SkillTap Bot and a new conversation window will be opened. For that matter, a separate conversation window is opened by an initial response from each subscriber. In another embodiment, a common window is opened for a session using Chat Room technology allowing the Initiator (User “A” to selectively allow more than one Subscriber to join the conversation in a common GUI window.
[0091] In one embodiment, an active agent responds to the publication of User “A”s initial message providing responses by querying a FAQ database. User “A” may or may not be informed that the responder is a robot Bot.
[0092] Referring to FIG. 26 at 1912 , after User “A” has finished his conversation with Subscriber “B”, he exits the special SkillTap GUI IM window 2601 . SkillTap provides the option for User “A” to elect 2602 to evaluate Subscriber “B”s help and to elect 2603 to create a FAQ.
[0093] In rating the Subscriber, the SkillTap application prompts User “A” for evaluation categories and ratings 2604 . SkillTap in a preferred embodiment, aggregates ratings for the subscriber (may be a simple averaging of scores accumulated from all requests to subscriber “B”) into a single rating. This score is optionally presented with any response from Subscriber “B”. It can also be used by filters to prioritize responses from subscribers. In one embodiment, evaluations of subscribers is also related to topic such that the same subscriber may have a value rating of 5 for computers and 3 for programs. The topics are pre-assigned by SkillTap.
[0094] If the user elects 2603 to create a FAQ, SkillTap provides an editable GUI containing the messages from the conversations from all subscribers responding to the request or in another embodiment 2606 , the GUI only displays the Subscriber “B” information. The GUI can optionally display related FAQ information as a result of a user query and can prompt User “A” to step him through the FAQ creation steps. When the user is satisfied with his new FAQ entry, SkillTap saves the results 2607 in the FAQ database. In one embodiment 2608 SkillTap associates User “A” with the FAQ entry such that when the FAQ is queried in the future, the users can see who the expert was that created the entry and how to contact him (network ID/Address, Phone etc). When the user is done, he closes his special SkillTap conversation GUI window 2609 .
[0095] While the preferred embodiment of the invention has been illustrated and described herein, it is to be understood that the invention is not limited to the precise construction herein disclosed, and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims. | A message received from a user causes a query of a dynamic database such as a FAQ or Relational Database, the results of the query are returned to the user. Furthermore the received message is published to a community of anonymous users. Optionally the user can edit the returned results and store the edited version in the dynamic database or edit the dynamic database via a GUI interface. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an ultrasonic imaging method and ultrasonic diagnostic apparatus, and more particularly to an ultrasonic imaging method and ultrasonic diagnostic apparatus that eliminate a problem that a good harmonic image cannot be obtained due to a fundamental component of received data for a previous ultrasonic pulse intruding into a fundamental component of received data for a current ultrasonic pulse at a considerable intensity.
[0002] [0002]FIG. 14 is an explanatory diagram showing timing of B-mode imaging in a conventional ultrasonic diagnostic apparatus. In FIG. 14, a fundamental component is indicated by a solid line and a harmonic component by a broken line because the fundamental component is principal and the harmonic component is subsidiary in the B mode.
[0003] When an ultrasonic pulse fs with a relatively shallow (e.g., 5 cm) focus is transmitted at a time t 1 , the fundamental component of received data (i.e., a component of received data having the same frequency as the transmission frequency) indicated by the solid line in FIG. 14 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component (i.e., a component of received data having a frequency twice as high as the transmission frequency) of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0004] A time t 2 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fs transmitted at the time t 1 decreases to a negligible level (e.g., the component becomes smaller than a noise component or a detection sensitivity).
[0005] When an ultrasonic pulse fm with a relatively intermediate (e.g., 10 cm) focus is transmitted at the time t 2 , the fundamental component of received data indicated by the solid line in FIG. 14 has an intensity decreasing over time with a maximum at the time t 2 . The harmonic component of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 .
[0006] A time t 3 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fm transmitted at the time t 2 decreases to a negligible level.
[0007] When an ultrasonic pulse fd with a relatively deep (e.g., 15 cm) focus is transmitted at the time t 3 , the fundamental component of received data indicated by the solid line in FIG. 14 has an intensity decreasing over time with a maximum at the time t 3 . The harmonic component of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 .
[0008] A time t 4 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fd transmitted at the time t 3 decreases to a negligible level.
[0009] When an ultrasonic pulse fs with a relatively shallow (e.g., 5 cm) focus is transmitted at the time t 4 , the fundamental component of received data indicated by the solid line in FIG. 14 has an intensity decreasing over time with a maximum at the time t 4 . The harmonic component of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 4 .
[0010] A similar operation is repeated thereafter.
[0011] The frame rate is 1/(τs+τm+τd)÷N, where the interval between the times t 1 and t 2 is represented by τs, the interval between the times t 2 and t 3 is represented by τm, the interval between the times t 3 and t 4 is represented by τd, the ultrasonic pulses fs, fm and fd gives one acoustic line, and the number of acoustic lines in one frame is N. Moreover, τs<τm<τd.
[0012] If the transmission intervals for the ultrasonic pulses fs, fm and fd are uniformly set to τs, the received data for the ultrasonic pulse fm remains at a considerable intensity when reception of received data for the ultrasonic pulse fd is started, compromising imaging. Moreover, the received data for the ultrasonic pulse fd remains at a considerable intensity when reception of received data for the ultrasonic pulse fs is started, compromising imaging.
[0013] If the intervals are uniformly set to τm, the received data for the ultrasonic pulse fd remains at a considerable intensity when reception of received data for the ultrasonic pulse fs is started, compromising imaging.
[0014] On the other hand, the intervals uniformly set to τd do no harm in imaging.
[0015] However, the frame rate is 1/(3·τd)÷N, which is lower than that in FIG. 14.
[0016] In other words, the ultrasonic pulses fs, fm and fd are transmitted at timing as shown in FIG. 14 so that a higher frame rate can be achieved.
[0017] [0017]FIG. 15 is an explanatory diagram showing timing of harmonic-mode imaging according to a filtering technique in the conventional ultrasonic diagnostic apparatus.
[0018] In FIG. 15, a harmonic component is indicated by a solid line and a fundamental component by a broken line because the harmonic component is principal and the fundamental component is subsidiary in the harmonic mode. Moreover, the gain is increased to acquire large harmonic components that are inherently small, and accordingly, the fundamental components become larger.
[0019] The timing for transmitting the ultrasonic pulses in FIG. 15 is exactly the same as that in the B mode shown in FIG. 14.
[0020] [0020]FIG. 16 is an explanatory diagram showing timing of harmonic-mode imaging according to a phase inversion technique in the conventional ultrasonic diagnostic apparatus.
[0021] When a first ultrasonic pulse fs+ with a relatively shallow focus is transmitted at a time t 1 , the fundamental component of received data indicated by the broken line in FIG. 16 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0022] When a second ultrasonic pulse fs− with a relatively shallow focus and of a phase opposite to that of the first ultrasonic pulse fs+ is transmitted at a time t 2 after a time period is from the time t 1 as in the B mode, the fundamental component of received data indicated by the broken line in FIG. 16 has an intensity decreasing over time with a maximum at the time t 2 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 .
[0023] Adding the first and second received data, the fundamental components are canceled out because their phases are opposite, and the harmonic components are doubled because they are in phase. That is, solely the harmonic components can be obtained.
[0024] When a first ultrasonic pulse fm+ with a relatively intermediate focus is transmitted at a time t 3 ′ after a time period τs from the time t 2 as in the B mode, the fundamental component of received data indicated by the broken line in FIG. 16 has an intensity decreasing over time with a maximum at the time t 3 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 ′.
[0025] When a second ultrasonic pulse fm− with a relatively intermediate focus and of a phase opposite to that of the first ultrasonic pulse fm+ is transmitted at a time t 4 ′ after a time period τm from the time t 3 ′ as in the B mode, the fundamental component of received data indicated by the broken line in FIG. 16 has an intensity decreasing over time with a maximum at the time t 4 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 4 ′.
[0026] Adding the first and second received data, the fundamental components are canceled out because their phases are opposite, and the harmonic components are doubled because they are in phase. That is, solely the harmonic components can be obtained.
[0027] When a first ultrasonic pulse fd+ with a relatively deep focus is transmitted at a time t 5 ′ after a time period τm from the time t 4 ′ as in the B mode, the fundamental component of received data indicated by the broken line in FIG. 16 has an intensity decreasing over time with a maximum at the time t 5 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 5 ′.
[0028] When a second ultrasonic pulse fd− with a relatively deep focus and of a phase opposite to that of the first ultrasonic pulse fd+ is transmitted at a time t 6 ′ after a time period id from the time t 5 ′ as in the B mode, the fundamental component of received data indicated by the broken line in FIG. 16 has an intensity decreasing over time with a maximum at the time t 6 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 6 ′.
[0029] Adding the first and second received data, the fundamental components are canceled out because their phases are opposite, and the harmonic components are doubled because they are in phase. That is, solely the harmonic components can be obtained.
[0030] Then, a first ultrasonic pulse fs+ with a relatively shallow focus is transmitted at a time t 7 ′ after a time period τd from the time t 6 ′ as in the B mode.
[0031] A similar operation is repeated thereafter.
[0032] In the harmonic mode in the conventional ultrasonic diagnostic apparatus, transmission timing for the ultrasonic pulses is the same as that in the B mode.
[0033] However, the transmission timing for the ultrasonic pulses in the B mode is such that a next ultrasonic pulse is transmitted when the fundamental component of received data for a previous ultrasonic pulse decreases to a negligible level using a small gain. If the same timing is employed in the harmonic mode in which the gain is increased, the next ultrasonic pulse is transmitted when the fundamental component of received data for the previous ultrasonic pulse has not decreased to a negligible level.
[0034] Thus, the filtering technique has a problem that a good harmonic image cannot be obtained because the subsidiary fundamental component has a fundamental component of received data for a previous ultrasonic pulse intruding at a considerable intensity.
[0035] In the phase inversion technique, although the fundamental components are to be canceled out by addition, the fundamental component of received data for the ultrasonic pulse fs− intrudes, for example, when the ultrasonic pulse fm+ is transmitted; and the fundamental component of received data for the ultrasonic pulse fm+ intrudes when the ultrasonic pulse fm− is transmitted, as shown in FIG. 16. Thus, the intruding fundamental components cannot be canceled out because they are different, thereby also posing a problem that a good harmonic image cannot be obtained.
SUMMARY OF THE INVENTION
[0036] It is therefore an object of the present invention to provide an ultrasonic imaging method and ultrasonic diagnostic apparatus that eliminate a problem that a good harmonic image cannot be obtained due to a fundamental component of received data for a previous ultrasonic pulse intruding into a fundamental component of received data for a current ultrasonic pulse with a considerable intensity.
[0037] The present invention, in accordance with its first aspect, provides an ultrasonic imaging method for transmitting an ultrasonic pulse into a subject and receiving an ultrasonic echo from the subject corresponding to said ultrasonic pulse to generate received data, and acquiring harmonic-mode data employing a harmonic component from said received data, characterized in comprising: after transmitting an ultrasonic pulse to a focus on a certain acoustic line, transmitting a next ultrasonic pulse at a time interval such that no effect is received from an ultrasonic echo associated with said former ultrasonic pulse.
[0038] In the ultrasonic imaging method of the first aspect, since a next ultrasonic pulse is transmitted at a sufficient time interval after transmitting an ultrasonic pulse to a focus on a certain acoustic line, a fundamental component of received data for a previous ultrasonic pulse is prevented from intruding into a fundamental component of received data for a current ultrasonic pulse at a considerable intensity. Therefore, a good harmonic image can be obtained.
[0039] The present invention, in accordance with its second aspect, provides an ultrasonic imaging method for transmitting an ultrasonic pulse into a subject and receiving an ultrasonic echo from the subject corresponding to said ultrasonic pulse to generate received data, and acquiring harmonic-mode data employing a harmonic component from said received data, characterized in comprising: after transmitting an ultrasonic pulse to a focus on a certain acoustic line, transmitting a next ultrasonic pulse to a focus on an acoustic line spaced apart to a degree such that an ultrasonic pulse associated with said former ultrasonic pulse is negligible.
[0040] In the ultrasonic imaging method of the second aspect, since a next ultrasonic pulse is transmitted to a next focus sufficiently spaced apart after transmitting an ultrasonic pulse to a focus on a certain acoustic line, a fundamental component of received data for a previous ultrasonic pulse is prevented from intruding into a fundamental component of received data for a current ultrasonic pulse at a considerable intensity. Therefore, a good harmonic image can be obtained.
[0041] The present invention, in accordance with its third aspect, provides an ultrasonic imaging method for transmitting a first ultrasonic pulse into a subject and receiving a first ultrasonic echo from the subject corresponding to said first ultrasonic pulse to generate first received data; next transmitting a second ultrasonic pulse of a phase opposite to that of said first ultrasonic pulse into the subject and receiving a second ultrasonic echo from the subject corresponding to said second ultrasonic pulse to generate second received data; and acquiring harmonic-mode data based on a sum of said first and second received data, characterized in comprising: after transmitting said first ultrasonic pulse, transmitting said second ultrasonic pulse at a time interval such that said second ultrasonic echo is not affected by said first ultrasonic pulse.
[0042] In the ultrasonic imaging method of the third aspect, since the second ultrasonic pulse is transmitted at a sufficient time interval after transmitting the first ultrasonic pulse, a fundamental component of received data for the first ultrasonic pulse is prevented from intruding into a fundamental component of received data for the second ultrasonic pulse at a considerable intensity. Therefore, a good harmonic image can be obtained.
[0043] The present invention, in accordance with its fourth aspect, provides an ultrasonic imaging method for transmitting a first ultrasonic pulse into a subject and receiving a first ultrasonic echo from the subject corresponding to said first ultrasonic pulse to generate first received data; next transmitting a second ultrasonic pulse of a phase opposite to that of said first ultrasonic pulse into the subject and receiving a second ultrasonic echo from the subject corresponding to said second ultrasonic pulse to generate second received data; and acquiring harmonic-mode data based on a sum of said first and second received data, characterized in comprising: sequentially transmitting said first ultrasonic pulse to a plurality of foci on the same acoustic line, and then sequentially transmitting said second ultrasonic pulse to the plurality of foci on the same acoustic line.
[0044] In the ultrasonic imaging method of the fourth aspect, since the fundamental component of received data for an ultrasonic pulse transmitted before the first ultrasonic pulse, which component is to intrude into a fundamental component of received data for the first ultrasonic pulse, and the fundamental component of received data for an ultrasonic pulse transmitted before the second ultrasonic pulse, which component is to intrude into a fundamental component of received data for the second ultrasonic pulse, become identical, the intruding fundamental components are canceled out by addition. Therefore, a good harmonic image can be obtained.
[0045] The present invention, in accordance with its fifth aspect, provides an ultrasonic imaging method for transmitting a first ultrasonic pulse into a subject and receiving a first ultrasonic echo from the subject corresponding to said first ultrasonic pulse to generate first received data; next transmitting a second ultrasonic pulse of a phase opposite to that of said first ultrasonic pulse into the subject and receiving a second ultrasonic echo from the subject corresponding to said second ultrasonic pulse to generate second received data; and acquiring harmonic-mode data based on a sum of said first and second received data, characterized in comprising: between the transmission of said first ultrasonic pulse and the transmission of said second ultrasonic pulse to a certain focus, conducting transmission of said first or second ultrasonic pulse to one or more foci on one or more other acoustic lines.
[0046] In the ultrasonic imaging method of the fifth aspect, since, after transmitting the first ultrasonic pulse, the next ultrasonic pulse is transmitted to a next focus sufficiently spaced apart, and then the second ultrasonic pulse is transmitted, a fundamental component of received data for a previous ultrasonic pulse is prevented from intruding into fundamental components of received data for the first and second ultrasonic pulses at a considerable intensity. Therefore, the intruding fundamental component is prevented from obstructing obtainment of a good harmonic image.
[0047] The present invention, in accordance with its sixth aspect, provides the ultrasonic imaging method having the aforesaid configuration, characterized in that the time between transmission of an ultrasonic pulse and transmission of a next ultrasonic pulse is shortened as a corresponding focus is shallower.
[0048] In the ultrasonic imaging method of the sixth aspect, since the transmission interval for the ultrasonic pulses is shortened when the focus is shallower and an ultrasonic echo decays more rapidly, and the transmission interval for the ultrasonic pulses is lengthened when the focus is deeper and an ultrasonic echo decays more slowly, the frame rate can be increased without any harm in imaging.
[0049] The present invention, in accordance with its seventh aspect, provides the ultrasonic imaging method having the aforesaid configuration, characterized in that the transmission interval for the ultrasonic pulses in a B mode is shorter than the transmission interval for the ultrasonic pulses in a harmonic mode for the same focus.
[0050] In the ultrasonic imaging method of the seventh aspect, since the transmission interval for the ultrasonic pulses is longer in the harmonic mode in which the gain is larger, and the transmission interval for the ultrasonic pulses is shorter in the B mode in which the gain is smaller, the frame rate can be increased in the B mode without any harm in imaging.
[0051] The present invention, in accordance with its eighth aspect, provides the ultrasonic imaging method having the aforesaid configuration, characterized in that the transmission interval for the ultrasonic pulses in a harmonic mode is equal to the transmission interval for the ultrasonic pulses in a B mode for the same focus.
[0052] In the ultrasonic imaging method of the eighth aspect, since the transmission intervals for the ultrasonic pulses in the harmonic mode and in the B-mode are equal, the frame rate can be consistent.
[0053] The present invention, in accordance with its ninth aspect, provides an ultrasonic diagnostic apparatus comprising an ultrasonic probe; transmitting/receiving means for driving said ultrasonic probe to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data; harmonic-mode data generating means for acquiring harmonic-mode data employing a harmonic component from said received data; image producing means for producing a harmonic-mode image based on said harmonic-mode data; and display means for displaying said harmonic-mode image, characterized in that said transmitting/receiving means transmits, after transmitting an ultrasonic pulse to a focus on a certain acoustic line, a next ultrasonic pulse at a time interval such that no effect is received from an ultrasonic echo associated with said former ultrasonic pulse.
[0054] In the ultrasonic diagnostic apparatus of the ninth aspect, the ultrasonic imaging method as described regarding the first aspect can be suitably implemented.
[0055] The present invention, in accordance with its tenth aspect, provides an ultrasonic diagnostic apparatus comprising an ultrasonic probe; transmitting/receiving means for driving said ultrasonic probe to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data; harmonic-mode data generating means for acquiring harmonic-mode data employing a harmonic component from said received data; image producing means for producing a harmonic-mode image based on said harmonic-mode data; and display means for displaying said harmonic-mode image, characterized in that said transmitting/receiving means transmits, after transmitting an ultrasonic pulse to a focus on a certain acoustic line, a next ultrasonic pulse to a focus on an acoustic line spaced apart to a degree such that an ultrasonic pulse associated with said former ultrasonic pulse is negligible.
[0056] In the ultrasonic diagnostic apparatus of the tenth aspect, the ultrasonic imaging method as described regarding the second aspect can be suitably implemented.
[0057] The present invention, in accordance with its eleventh aspect, provides an ultrasonic diagnostic apparatus comprising an ultrasonic probe; transmitting/receiving means for driving said ultrasonic probe to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data; harmonic-mode data generating means for acquiring harmonic-mode data based on a sum of first received data corresponding to a first ultrasonic pulse and second received data corresponding to a second ultrasonic pulse of a phase opposite to said first ultrasonic pulse; image producing means for producing a harmonic-mode image based on said harmonic-mode data; and display means for displaying said harmonic-mode image, characterized in that said transmitting/receiving means transmits, after transmitting said first ultrasonic pulse, said second ultrasonic pulse at a time interval such that said second ultrasonic echo is not affected by said first ultrasonic pulse.
[0058] In the ultrasonic diagnostic apparatus of the eleventh aspect, the ultrasonic imaging method as described regarding the third aspect can be suitably implemented.
[0059] The present invention, in accordance with its twelfth aspect, provides the ultrasonic diagnostic apparatus having the aforesaid configuration, characterized in that said transmitting/receiving means sequentially transmits said first ultrasonic pulse to a plurality of foci on the same acoustic line, and then sequentially transmits said second ultrasonic pulse to the plurality of foci on the same acoustic line.
[0060] In the ultrasonic diagnostic apparatus of the twelfth aspect, the ultrasonic imaging method as described regarding the fourth aspect can be suitably implemented.
[0061] The present invention, in accordance with its thirteenth aspect, provides the ultrasonic diagnostic apparatus having the aforesaid configuration, characterized in that said transmitting/receiving means conducts, between the transmission of said first ultrasonic pulse and the transmission of said second ultrasonic pulse to a certain focus, transmission of said first or second ultrasonic pulse to one or more foci on one or more other acoustic lines.
[0062] In the ultrasonic diagnostic apparatus of the thirteenth aspect, the ultrasonic imaging method as described regarding the fifth aspect can be suitably implemented.
[0063] The present invention, in accordance with its fourteenth aspect, provides the ultrasonic diagnostic apparatus having the aforesaid configuration, characterized in that said transmitting/receiving means shortens the time between transmission of an ultrasonic pulse and transmission of a next ultrasonic pulse as a corresponding focus is shallower.
[0064] In the ultrasonic diagnostic apparatus of the fourteenth aspect, the ultrasonic imaging method as described regarding the sixth aspect can be suitably implemented.
[0065] The present invention, in accordance with its fifteenth aspect, provides the ultrasonic diagnostic apparatus having the aforesaid configuration, characterized in that said transmitting/receiving means makes the transmission interval of ultrasonic pulses in a B mode shorter than the transmission interval of ultrasonic pulses in a harmonic mode for the same focus.
[0066] In the ultrasonic diagnostic apparatus of the fifteenth aspect, the ultrasonic imaging method as described regarding the seventh aspect can be suitably implemented.
[0067] The present invention, in accordance with its sixteenth aspect, provides the ultrasonic diagnostic apparatus having the aforesaid configuration, characterized in that said transmitting/receiving means makes the transmission interval of ultrasonic pulses in a harmonic mode equal to the transmission interval of ultrasonic pulses in a B mode for the same focus.
[0068] In the ultrasonic diagnostic apparatus of the sixteenth aspect, the ultrasonic imaging method as described regarding the eighth aspect can be suitably implemented.
[0069] According to the ultrasonic imaging method and ultrasonic diagnostic apparatus of the present invention, the intrusion of a fundamental component of received data for a previous ultrasonic pulse into a fundamental component of received data for a current ultrasonic pulse at a considerable intensity is prevented from obstructing obtainment of a good harmonic image, and hence, a good harmonic image can be obtained.
[0070] Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0071] [0071]FIG. 1 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a first embodiment.
[0072] [0072]FIG. 2 is a timing chart showing the operation in a B mode in the ultrasonic diagnostic apparatus in accordance with the first embodiment.
[0073] [0073]FIG. 3 is a timing chart showing the operation in a harmonic mode in the ultrasonic diagnostic apparatus in accordance with the first embodiment.
[0074] [0074]FIG. 4 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a second embodiment.
[0075] [0075]FIG. 5 is a diagram for explaining acoustic lines constituting a frame and foci on the acoustic lines.
[0076] [0076]FIG. 6 is a timing chart showing the operation in a harmonic mode in the ultrasonic diagnostic apparatus in accordance with the second embodiment.
[0077] [0077]FIG. 7 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a third embodiment.
[0078] [0078]FIG. 8 is a timing chart showing the operation in a harmonic mode in the ultrasonic diagnostic apparatus in accordance with the third embodiment.
[0079] [0079]FIG. 9 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a fourth embodiment.
[0080] [0080]FIG. 10 is a timing chart showing the operation in a harmonic mode in the ultrasonic diagnostic apparatus in accordance with the fourth embodiment.
[0081] [0081]FIG. 11 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a fifth embodiment.
[0082] [0082]FIG. 12 is a diagram for explaining acoustic lines constituting a frame and foci on the acoustic lines.
[0083] [0083]FIG. 13 is a timing chart showing the operation in a harmonic mode in the ultrasonic diagnostic apparatus in accordance with the fifth embodiment.
[0084] [0084]FIG. 14 is a timing chart showing the operation in a B mode in a conventional ultrasonic diagnostic apparatus.
[0085] [0085]FIG. 15 is a timing chart showing the operation in a harmonic mode according to a filtering technique in the conventional ultrasonic diagnostic apparatus.
[0086] [0086]FIG. 16 is a timing chart showing the operation in a harmonic mode according to a phase inversion technique in the conventional ultrasonic diagnostic apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0087] The present invention will now be described in more detail with reference to several embodiments shown in the accompanying drawings.
[0088] First Embodiment
[0089] [0089]FIG. 1 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a first embodiment.
[0090] The ultrasonic diagnostic apparatus 10 comprises an ultrasonic probe 1 , a transmitting/receiving section 12 for driving the ultrasonic probe 1 to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data, a filtering section 13 for acquiring harmonic-mode data employing a harmonic component from the received data, a mode switching section 4 for switching between a B mode and a harmonic mode, a B-mode processing section 5 for generating image data from the received data or harmonic-mode data, a DSC 6 for generating image display data, and a CRT 7 for displaying an image.
[0091] [0091]FIG. 2 is an explanatory diagram showing imaging timing when a B mode is selected at the mode switching section 4 .
[0092] In FIG. 2, a fundamental component is indicated by a solid line and a harmonic component by a broken line because the fundamental component is principal and the harmonic component is subsidiary in the B mode.
[0093] When an ultrasonic pulse fs with a relatively shallow (e.g., 5 cm) focus is transmitted at a time t 1 , the fundamental component of received data (i.e., a component of received data having the same frequency as the transmission frequency) indicated by the solid line in FIG. 2 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component (i.e., a component of received data having a frequency twice as high as the transmission frequency) of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0094] A time t 2 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fs transmitted at the time t 1 decreases to a negligible level (e.g., the component becomes smaller than a noise component or a detection sensitivity).
[0095] When an ultrasonic pulse fm with a relatively intermediate (e.g., 10 cm) focus is transmitted at the time t 2 , the fundamental component of received data indicated by the solid line in FIG. 2 has an intensity decreasing over time with a maximum at the time t 2 . The harmonic component of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 .
[0096] A time t 3 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fm transmitted at the time t 2 decreases to a negligible level.
[0097] When an ultrasonic pulse fd with a relatively deep (e.g., 15 cm) focus is transmitted at the time t 3 , the fundamental component of received data indicated by the solid line in FIG. 2 has an intensity decreasing over time with a maximum at the time t 3 . The harmonic component of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 .
[0098] A time t 4 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fd transmitted at the time t 3 decreases to a negligible level.
[0099] When an ultrasonic pulse fs with a relatively shallow (e.g., 5 cm) focus is transmitted at the time t 4 , the fundamental component of received data indicated by the solid line in FIG. 2 has an intensity decreasing over time with a maximum at the time t 4 . The harmonic component of the received data indicated by the broken line has an intensity rapidly decreasing over time with a maximum slightly after the time t 4 .
[0100] A similar operation is repeated thereafter.
[0101] The frame rate is 1/(τs+τm+τd)÷N, where the interval between the times t 1 and t 2 is represented by τs, the interval between the times t 2 and t 3 is represented by τm, the interval between the times t 3 and t 4 is represented by τd, the ultrasonic pulses fs, fm and fd gives one acoustic line, and the number of acoustic lines in one frame is N. Moreover, τs<τm<τd.
[0102] If the transmission intervals for the ultrasonic pulses fs, fm and fd are uniformly set to τs, the received data for the ultrasonic pulse fm remains at a considerable intensity when reception of received data for the ultrasonic pulse fd is started, compromising imaging. Moreover, the received data for the ultrasonic pulse fd remains at a considerable intensity when reception of received data for the ultrasonic pulse fs is started, compromising imaging.
[0103] If the intervals are uniformly set to τm, the received data for the ultrasonic pulse fd remains at a considerable intensity when reception of received data for the ultrasonic pulse fs is started, compromising imaging.
[0104] On the other hand, the intervals uniformly set to τd do no harm in imaging.
[0105] However, the frame rate is 1/(3·τd)÷N, which is lower than that in FIG. 2.
[0106] In other words, the ultrasonic pulses fs, fm and fd are transmitted at timing as shown in FIG. 2 so that a higher frame rate can be achieved.
[0107] [0107]FIG. 3 is an explanatory diagram showing imaging timing when a harmonic mode is selected at the mode switching section 4 .
[0108] In FIG. 3, a harmonic component is indicated by a solid line and a fundamental component by a broken line because the harmonic component is principal and the fundamental component is subsidiary in the harmonic mode. Moreover, the gain is increased to acquire large harmonic components that are inherently small, and accordingly, the fundamental components become larger.
[0109] When an ultrasonic pulse fs with a relatively shallow focus is transmitted at a time t 1 , the fundamental component of received data indicated by the broken line in FIG. 3 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0110] A time T 2 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fs transmitted at the time t 1 decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τs+Δs) from the time t 1 to the time T 2 is longer than the time period τs in the B mode.
[0111] When an ultrasonic pulse fm with a relatively intermediate focus is transmitted at the time T 2 , the fundamental component of received data indicated by the broken line in FIG. 3 has an intensity decreasing over time with a maximum at the time T 2 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time T 2 .
[0112] A time T 3 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fm transmitted at the time T 2 decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τm+Δm) from the time T 2 to the time T 3 is longer than the time period τm in the B mode.
[0113] When an ultrasonic pulse fd with a relatively deep focus is transmitted at the time T 3 , the fundamental component of received data indicated by the broken line in FIG. 3 has an intensity decreasing over time with a maximum at the time T 3 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time T 3 .
[0114] A time T 4 is a time point when the intensity of the fundamental component of the received data for the ultrasonic pulse fd transmitted at the time T 3 decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τd+Δd) from the time T 3 to the time T 4 is longer than the time period τd in the B mode.
[0115] When an ultrasonic pulse fs with a relatively shallow focus is transmitted at the time T 4 , the fundamental component of received data indicated by the broken line in FIG. 3 has an intensity decreasing over time with a maximum at the time T 4 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time T 4 .
[0116] A similar operation is repeated thereafter.
[0117] The frame rate is 1/(τs+Δs+τm+Δm+τd+Δd)÷N, where the ultrasonic pulses fs, fm and fd gives one acoustic line, and the number of acoustic lines in one frame is N. Moreover, τs+Δs<τm+Δm<τd+Δd.
[0118] If the transmission intervals for the ultrasonic pulses fs, fm and fd are uniformly set to τs+Δs, the received data for the ultrasonic pulse fm remains at a considerable intensity when reception of received data for the ultrasonic pulse fd is started, compromising imaging. Moreover, the received data for the ultrasonic pulse fd remains at a considerable intensity when reception of received data for the ultrasonic pulse fs is started, compromising imaging.
[0119] If the intervals are uniformly set to τm+Δm, the received data for the ultrasonic pulse fd remains at a considerable intensity when reception of received data for the ultrasonic pulse fs is started, compromising imaging.
[0120] On the other hand, the intervals uniformly set to τd+Δd do no harm in imaging.
[0121] However, the frame rate is 1/{3·(τd+Δd)}÷N, which is lower than that in FIG. 3.
[0122] In other words, by transmitting the ultrasonic pulses fs, fm and fd at timing as shown in FIG. 3, a high frame rate can be achieved. Moreover, since a current ultrasonic pulse is transmitted after the fundamental component of received data for a previous ultrasonic pulse has decreased to a negligible intensity, harm due to intrusion is prevented, thus providing a good harmonic image.
[0123] Second Embodiment
[0124] [0124]FIG. 4 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a second embodiment.
[0125] The ultrasonic diagnostic apparatus 20 comprises an ultrasonic probe 1 , a transmitting/receiving section 22 for driving the ultrasonic probe 1 to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data, a filtering section 13 for acquiring harmonic-mode data employing a harmonic component from the received data, a mode switching section 4 for switching between a B mode and a harmonic mode, a B-mode processing section 5 for generating image data from the received data or harmonic-mode data, a DSC 6 for generating image display data, and a CRT 7 for displaying an image.
[0126] The imaging timing when the B mode is selected at the mode switching section 4 is the same as that in FIG. 2 (first embodiment).
[0127] [0127]FIG. 5 is a conceptual diagram of acoustic lines constituting one frame.
[0128] It is assumed that one acoustic line is acquired by an ultrasonic pulse fs with a shallow focus, an ultrasonic pulse fm with an intermediate focus, and an ultrasonic pulse fd with a deep focus, and one frame is formed by acoustic lines # 0 -# 5 in different directions.
[0129] [0129]FIG. 6 is an explanatory diagram showing imaging timing when a harmonic mode is selected at the mode switching section 4 .
[0130] When an ultrasonic pulse # 0 fs with a relatively shallow focus on the acoustic line # 0 is transmitted at a time t 1 , the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0131] A time t 2 is after a time period τs from the time t 1 as in the B mode.
[0132] When an ultrasonic pulse # 3 fs with a relatively shallow focus on the acoustic line # 3 is transmitted at the time t 2 , the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 2 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 .
[0133] The time period τs from the time t 1 to the time t 2 is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 0 fs intrudes into the fundamental component for the ultrasonic pulse # 3 fs, it is at a negligible degree.
[0134] A time t 3 ′ is after a time period τs from the time t 2 .
[0135] When an ultrasonic pulse # 0 fm with a relatively intermediate focus on the acoustic line # 0 is transmitted at the time t 3 ′, the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 3 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 ′.
[0136] The time period τs from the time t 2 to the time t 3 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 3 fs intrudes into the fundamental component for the ultrasonic pulse # 0 fm, it is at a negligible degree.
[0137] A time t 4 ′ is after a time period τm from the time t 3 ′.
[0138] When an ultrasonic pulse # 3 fm with a relatively intermediate focus on the acoustic line # 3 is transmitted at the time t 4 ′, the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 4 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 4 ′.
[0139] The time period τm from the time t 3 ′ to the time t 4 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 0 fm intrudes into the fundamental component for the ultrasonic pulse # 3 fm, it is at a negligible degree.
[0140] A time t 5 ′ is after a time period τm from the time t 4 ′.
[0141] When an ultrasonic pulse # 0 fd with a relatively deep focus on the acoustic line # 0 is transmitted at the time t 5 ′, the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 5 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 5 ′.
[0142] The time period τm from the time t 4 ′ to the time t 5 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 3 fm intrudes into the fundamental component for the ultrasonic pulse # 0 fd, it is at a negligible degree.
[0143] A time t 6 ′ is after a time period id from the time t 5 ′.
[0144] When an ultrasonic pulse # 3 fd with a relatively deep focus on the acoustic line # 3 is transmitted at the time t 6 ′, the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 6 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 6 ′.
[0145] The time period τd from the time t 5 ′ to the time t 6 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 0 fd intrudes into the fundamental component for the ultrasonic pulse # 3 fd, it is at a negligible degree.
[0146] A time t 7 ′ is after a time period τd from the time t 6 ′.
[0147] When an ultrasonic pulse # 1 fs with a relatively shallow focus on the acoustic line # 1 is transmitted at the time t 7 ′, the fundamental component of received data indicated by the broken line in FIG. 6 has an intensity decreasing over time with a maximum at the time t 7 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 7 ′.
[0148] The time period τd from the time t 6 ′ to the time t 7 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 1 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 3 fd intrudes into the fundamental component for the ultrasonic pulse # 1 fs, it is at a negligible degree.
[0149] A similar operation is repeated thereafter.
[0150] The frame rate is 1/(τs+τm+τd)÷N, i.e., a frame rate as high as that in the B-mode can be achieved. Moreover, since a current ultrasonic pulse is transmitted to a focus on an acoustic line in a different direction such that the fundamental component of received data for a previous ultrasonic pulse can be neglected, harm due to intrusion is prevented, thus providing a good harmonic image.
[0151] Third Embodiment
[0152] [0152]FIG. 7 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a third embodiment.
[0153] The ultrasonic diagnostic apparatus 30 comprises an ultrasonic probe 1 , a transmitting/receiving section 32 for driving the ultrasonic probe 1 to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data, a memory 8 for storing first received data corresponding to a first ultrasonic pulse, an adder 9 for acquiring harmonic-mode data by adding second received data corresponding to a second ultrasonic pulse of a phase opposite to the first ultrasonic pulse and the first received data stored in the memory 8 , a mode switching section 4 for switching between a B mode and a harmonic mode, a B-mode processing section 5 for generating image data from the received data or harmonic-mode data, a DSC 6 for generating image display data, and a CRT 7 for displaying an image.
[0154] The imaging timing when the B mode is selected at the mode switching section 4 is the same as that in FIG. 2 (first embodiment).
[0155] [0155]FIG. 8 is an explanatory diagram showing imaging timing when a harmonic mode is selected at the mode switching section 4 .
[0156] When a first ultrasonic pulse fs+ with a relatively shallow focus is transmitted at a time t 1 , the fundamental component of first received data indicated by the broken line in FIG. 8 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0157] A time t 2 ″ is a time point when the intensity of the fundamental component of the first received data for the first ultrasonic pulse fs+ transmitted at the time t 1 decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τs+δs) from the time t 1 to the time t 2 ″ is longer the time period τs in the B mode.
[0158] When a second ultrasonic pulse fs− with a relatively shallow focus and of a phase opposite to that of the first ultrasonic pulse fs+ is transmitted at the time t 2 ″, the fundamental component of second received data indicated by the broken line in FIG. 8 has an intensity decreasing over time with a maximum at the time t 2 ″. The harmonic component of the second received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 ″.
[0159] A time t 3 ″ is a time point when the intensity of the fundamental component of the second received data for the second ultrasonic pulse fs− transmitted at the time t 2 ″ decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τs+δs) from the time t 2 ″ to the time t 3 ″ is longer the time period τs in the B mode.
[0160] When a first ultrasonic pulse fm+ with a relatively intermediate focus is transmitted at the time t 3 ″, the fundamental component of first received data indicated by the broken line in FIG. 8 has an intensity decreasing over time with a maximum at the time t 3 ″. The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 ″.
[0161] A time t 4 ″ is a time point when the intensity of the fundamental component of the first received data for the first ultrasonic pulse fm+ transmitted at the time t 3 ″ decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τm+δm) from the time t 3 ″ to the time t 4 ″ is longer the time period τm in the B mode.
[0162] When a second ultrasonic pulse fm− with a relatively intermediate focus and of a phase opposite to that of the first ultrasonic pulse fm+ is transmitted at the time t 4 ″, the fundamental component of second received data indicated by the broken line in FIG. 8 has an intensity decreasing over time with a maximum at the time t 4 ″. The harmonic component of the second received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 4 ″.
[0163] A time t 5 ″ is a time point when the intensity of the fundamental component of the second received data for the second ultrasonic pulse fm− transmitted at the time t 4 ″ decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τm+δm) from the time t 4 ″ to the time t 5 ″ is longer the time period τm in the B mode.
[0164] When a first ultrasonic pulse fd+ with a relatively deep focus is transmitted at the time t 5 ″, the fundamental component of first received data indicated by the broken line in FIG. 8 has an intensity decreasing over time with a maximum at the time t 5 ″. The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 5 ″.
[0165] A time t 6 ″ is a time point when the intensity of the fundamental component of the first received data for the first ultrasonic pulse fd+ transmitted at the time t 5 ″ decreases to a negligible level. Since the fundamental component is larger than that in the B mode as described above, the time period (τd+δd) from the time t 5 ″ to the time t 6 ″ is longer the time period τd in the B mode.
[0166] When a second ultrasonic pulse fd− with a relatively deep focus and of a phase opposite to that of the first ultrasonic pulse fd+ is transmitted at the time t 6 ″, the fundamental component of second received data indicated by the broken line in FIG. 8 has an intensity decreasing over time with a maximum at the time t 6 ″. The harmonic component of the second received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 6 ″.
[0167] A similar operation is repeated thereafter.
[0168] Adding the first and second received data at the adder 9 , the fundamental components are canceled out because their phases are opposite, and the harmonic components are doubled because they are in phase. That is, solely the harmonic components can be obtained.
[0169] In the phase inversion technique shown in FIG. 8, since the fundamental component of received data for a previous ultrasonic pulse is decreased to a negligible intensity when transmitting a certain ultrasonic pulse, the previous fundamental component is prevented from intruding, thus providing a good harmonic image.
[0170] Fourth Embodiment
[0171] [0171]FIG. 9 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a fourth embodiment.
[0172] The ultrasonic diagnostic apparatus 40 comprises an ultrasonic probe 1 , a transmitting/receiving section 42 for driving the ultrasonic probe 1 to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data, a memory 8 s for storing first received data corresponding to a first ultrasonic pulse with a relatively shallow focus, a memory 8 m for storing first received data corresponding to a first ultrasonic pulse with a relatively intermediate focus, a memory 8 d for storing first received data corresponding to a first ultrasonic pulse with a relatively deep focus, a selector 43 for selecting from among the memories 8 s , 8 m and 8 d , an adder 9 for acquiring harmonic-mode data by adding second received data corresponding to a second ultrasonic pulse of a phase opposite to that of the first ultrasonic pulse and the first received data selected by the selector 43 , a mode switching section 4 for switching between a B mode and a harmonic mode, a B-mode processing section 5 for generating image data from the received data or harmonic-mode data, a DSC 6 for generating image display data, and a CRT 7 for displaying an image.
[0173] The imaging timing when the B mode is selected at the mode switching section 4 is the same as that in FIG. 2 (first embodiment).
[0174] [0174]FIG. 10 is an explanatory diagram showing imaging timing when a harmonic mode is selected at the mode switching section 4 .
[0175] When a first ultrasonic pulse fs+ with a relatively shallow focus is transmitted at a time t 1 , the fundamental component of first received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0176] A time t 2 is after a time period τs from the time t 1 as in the B mode.
[0177] When a first ultrasonic pulse fm+ with a relatively intermediate focus is transmitted at the time t 2 , the fundamental component of first received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 2 . The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 .
[0178] A time t 3 is after a time period τm from the time t 2 as in the B mode.
[0179] When a first ultrasonic pulse fd+ with a relatively deep focus is transmitted at the time t 3 , the fundamental component of first received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 3 . The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 .
[0180] A time t 4 is after a time period τd from the time t 3 as in the B mode.
[0181] When a second ultrasonic pulse fs− with a relatively shallow focus and of a phase opposite to that of the first ultrasonic pulse fs+ is transmitted at the time t 4 , the fundamental component of second received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 4 . The harmonic component of the second received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 4 .
[0182] A time t 5 is after a time period τs from the time t 4 as in the B mode.
[0183] When a second ultrasonic pulse fm− with a relatively intermediate focus and of a phase opposite to that of the first ultrasonic pulse fm+ is transmitted at the time t 5 , the fundamental component of second received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 5 . The harmonic component of the second received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 5 .
[0184] A time t 6 is after a time period τm from the time t 5 as in the B mode.
[0185] When a second ultrasonic pulse fd− with a relatively deep focus and of a phase opposite to that of the first ultrasonic pulse fd+ is transmitted at the time t 6 , the fundamental component of second received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 6 . The harmonic component of the second received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 6 .
[0186] A time t 7 is after a time period τd from the time t 6 as in the B mode.
[0187] When a first ultrasonic pulse fs+ with a relatively shallow focus on a next acoustic line is transmitted at the time t 7 , the fundamental component of first received data indicated by the broken line in FIG. 10 has an intensity decreasing over time with a maximum at the time t 7 . The harmonic component of the first received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 7 .
[0188] A similar operation is repeated thereafter.
[0189] Adding the first and second received data at the adder 9 , the fundamental components are canceled out because their phases are opposite, and the harmonic components are doubled because they are in phase. That is, solely the harmonic components can be obtained.
[0190] In the phase inversion technique shown in FIG. 10, the fundamental component of received data for the ultrasonic pulse fs+ intrudes when transmitting the first ultrasonic pulse fm+ at the time t 2 , for example, and the fundamental component of received data for the ultrasonic pulse fs− intrudes when transmitting the second ultrasonic pulse fm− at the time t 5 . Thus, since the intruding fundamental components are the same and of opposite phases, they are canceled out, thereby providing a good harmonic image.
[0191] Fifth Embodiment
[0192] [0192]FIG. 11 is a configuration diagram showing an ultrasonic diagnostic apparatus in accordance with a fifth embodiment.
[0193] The ultrasonic diagnostic apparatus 50 comprises an ultrasonic probe 1 , a transmitting/receiving section 52 for driving the ultrasonic probe 1 to transmit an ultrasonic pulse into a subject and receive an ultrasonic echo from the subject to output received data, a memory 8 a for storing first received data corresponding to a first ultrasonic pulse for a certain acoustic line, a memory 8 b for storing first received data corresponding to a first ultrasonic pulse for another acoustic line, a selector 53 for selecting from among the memories 8 a and 8 b , an adder for acquiring harmonic-mode data by adding second received data corresponding to a second ultrasonic pulse of a phase opposite to that of the first ultrasonic pulse, and a first received data selected by the selector 53 , a mode switching section 4 for switching between a B mode and a harmonic mode, a B-mode processing section 5 for generating image data from the received data or harmonic-mode data, a DSC 6 for generating image display data, and a CRT 7 for displaying an image.
[0194] The imaging timing when the B mode is selected at the mode switching section 4 is the same as that in FIG. 2 (first embodiment).
[0195] [0195]FIG. 12 is a conceptual diagram of acoustic lines constituting one frame.
[0196] It is assumed that one acoustic line is acquired by an ultrasonic pulse fs with a shallow focus, an ultrasonic pulse fm with an intermediate focus, and an ultrasonic pulse fd with a deep focus, and one frame is formed by acoustic lines # 0 -# 5 in different directions.
[0197] [0197]FIG. 13 is an explanatory diagram showing imaging timing when a harmonic mode is selected at the mode switching section 4 .
[0198] When a first ultrasonic pulse # 0 fs+ with a relatively shallow focus on the acoustic line # 0 is transmitted at a time t 1 , the fundamental component of received data indicated by the broken line in FIG. 13 has an intensity decreasing over time with a maximum at the time t 1 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 1 .
[0199] A time t 2 is after a time period τs from the time t 1 as in the B mode.
[0200] When a first ultrasonic pulse # 3 fs+ with a relatively shallow focus on the acoustic line # 3 is transmitted at the time t 2 , the fundamental component of received data indicated by the broken line in FIG. 13 has an intensity decreasing over time with a maximum at the time t 2 . The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 2 .
[0201] The time period τs from the time t 1 to the time t 2 is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 0 fs+ intrudes into the fundamental component for the ultrasonic pulse # 3 fs+, it is at a negligible degree.
[0202] A time t 3 ′ is after a time period τs from the time t 2 .
[0203] When a second ultrasonic pulse # 0 fs− with a relatively shallow focus on the acoustic line # 0 and of a phase opposite to that of the first ultrasonic pulse # 0 fs+ is transmitted at the time t 3 ′, the fundamental component of received data indicated by the broken line in FIG. 13 has an intensity decreasing over time with a maximum at the time t 3 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time t 3 ′.
[0204] The time period τs from the time t 2 to the time t 3 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 3 fs+ intrudes into the fundamental component for the ultrasonic pulse # 0 fs−, it is at a negligible degree.
[0205] A time T 4 ′ is after a time period τs from the time t 3 ′.
[0206] When a second ultrasonic pulse # 3 fs− with a relatively shallow focus on the acoustic line # 3 and of a phase opposite to that of the first ultrasonic pulse # 3 fs+ is transmitted at the time T 4 ′, the fundamental component of received data indicated by the broken line in FIG. 13 has an intensity decreasing over time with a maximum at the time T 4 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time T 4 ′.
[0207] The time period τs from the time t 3 ′ to the time T 4 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 0 fs− intrudes into the fundamental component for the ultrasonic pulse # 3 fs−, it is at a negligible degree.
[0208] A time T 5 ′ is after a time period τs from the time T 4 ′.
[0209] When a first ultrasonic pulse # 0 fm+ with a relatively intermediate focus on the acoustic line # 0 is transmitted at the time T 5 ′, the fundamental component of received data indicated by the broken line in FIG. 13 has an intensity decreasing over time with a maximum at the time T 5 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time T 5 ′.
[0210] The time period τs from the time T 4 ′ to the time T 5 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 3 fs− intrudes into the fundamental component for the ultrasonic pulse # 0 fm+, it is at a negligible degree.
[0211] A time T 6 ′ is after a time period τm from the time T 5 ′.
[0212] When a first ultrasonic pulse # 3 fm+ with a relatively intermediate focus on the acoustic line # 3 is transmitted at the time T 6 ′, the fundamental component of received data indicated by the broken line in FIG. 13 has an intensity decreasing over time with a maximum at the time T 6 ′. The harmonic component of the received data indicated by the solid line has an intensity rapidly decreasing over time with a maximum slightly after the time T 6 ′.
[0213] The time period τm from the time T 5 ′ to the time T 6 ′ is the same as that in the B mode in spite of the larger fundamental component. However, since the acoustic lines # 0 and # 3 are in different directions, even if the fundamental component for the ultrasonic pulse # 0 fm+ intrudes into the fundamental component for the ultrasonic pulse # 3 fm+, it is at a negligible degree.
[0214] A similar operation is repeated thereafter.
[0215] Adding the first and second received data at the adder 9 , the fundamental components are canceled out because their phases are opposite, and the harmonic components are doubled because they are in phase. That is, solely the harmonic components can be obtained.
[0216] In the phase inversion technique shown in FIG. 13, since a current ultrasonic pulse is transmitted to a focus on an acoustic line in a different direction such that the fundamental component of received data for a previous ultrasonic pulse can be neglected, harm due to intrusion is prevented, thus providing a good harmonic image.
[0217] Many widely different embodiments of the invention may be constructed without departing from the spirit and the scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims. | For the purpose of eliminating a problem that a good harmonic image cannot be obtained due to the tail of a fundamental component of previous received data intruding into a fundamental component of current received data; in the operation in a harmonic mode according to a phase inversion technique, a first ultrasonic pulse is sequentially transmitted to a plurality of foci on the same acoustic line, and a second ultrasonic pulse of a phase opposite to that of the first ultrasonic pulse is sequentially transmitted to the plurality of foci on the same acoustic line. | 1 |
TECHNICAL FIELD
[0001] The present invention generally relates to a net, and more specifically to an expandable knitted net comprising a plurality of fill yarns with elastomeric properties that allows the net to expand in the cross-direction, or a plurality of chain yarns with dissimilar elongation performance.
BACKGROUND OF THE INVENTION
[0002] Netting is often prepared either by knitting, weaving, or extrusion. Knitted netting typically comprises a plurality of threads oriented in a first direction and being essentially equal spaced from one another, and having wefts oriented in a second direction which is perpendicular to the first direction, the threads and wefts being interlocked and secured. Nets may be prepared by a Raschel knitting method, a process in which the threads are attached to knitting elements that comprise two needles and knock-over comb bars positioned opposite to one another, and comprising ground guide bars, pattern guide bars and stitch comb bars. An example of such a knitted net is described in European Patent No. 0 723 606, to Fryszer, et al., incorporated herein by reference.
[0003] Knitted netting has a variety of end use applications, including but not limited to hay bale wrap, cargo wrap, netted bags, and drainage nets. Raschel knitted nets have been used for round hay bale wrapping as disclosed in U.S. Pat. No. 4,569,439 and No. 4,570,789, both hereby incorporated by reference. Twines and films have also been used to tie up hay bales; however the twine usually cuts in the bale and doesn't provide ample support to keep the bale tidy and neat. Further, the twining of the rolled bales with the binding yarn is relatively time-consuming and requires substantial manual labor. Film covers don't allow the rolled bale enough air circulation, which lead to the growth of mold and eventually rotting. The Raschel knitted net doesn't cut into the hay bale and allows ample amount of air to circulate through the bale. Although Raschel knitted netting has several advantages over twine and plastic film, the netting tends to shrink in overall width when pulled lengthwise. Due to the shrinkage in the width, the outer most edges of the hay bale are left exposed, which can cause the bale to become disheveled during pick-up and transport.
[0004] There is an unmet need for a net that will provide maximum coverage to a rounded bale maintaining the rolled bale compact shape during pick-up and transport, as well as during storage.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a knitted net, and more specifically to an expandable knitted net. In one form, the net comprises a plurality of fill yarns with an elastomeric performance, which allows the net to expand in the cross-direction. In another form, the present invention is directed to a netting, and more specifically to a knitted netting comprising a plurality of chain yarns with dissimilar elongation performance oriented in a first direction, and a plurality of fill yarns oriented in a second direction, wherein the yarns oriented in the second direction secure the yarns oriented in the first direction in position within the netting.
[0006] In accordance with the present invention, the netting is used as bale wrap. In one form, the bale wrap comprises a plurality of chain yarns orientated in a first direction and a plurality of fill yarns orientated in a second direction. The elastomeric performance of the fill yarns provide for optimal coverage of the bale upon stretching of the netting. When stretched in the cross-direction, the netting easily conforms about the shape of a rolled bale, hugging the surface so as to maintain the compact nature of the rolled bale. In another form of the present invention, the netting is used as bale wrap. The bale wrap comprises a plurality of chain yarns oriented in a first direction, wherein the yarns have dissimilar elongation performances. The dissimilar elongation performances of the yarns provide for optimal coverage of the bale upon stretching of the netting. In order to achieve the desired necking performance when stretching the netting, the yarns located proximal to either edge have a higher elongation performance than those located distal to the outer edges Upon stretching, those yarns located proximal the outer edges stretch further than those located distal to the outer edges. This causes the outer edge of the net to flair, allowing the net to fold over the edges of the hay bale, maintaining the compact nature of the rolled bale.
[0007] The yarns of the present invention may comprise flat filaments, such as tapes, mono-filaments, or a combination thereof. The filaments may be of similar or dissimilar polymeric compositions. Suitable filaments, which may be blended in whole or part with natural or synthetic polymeric compositions, include polyamides, polyesters, polyolefins, polyvinyls, polyacrylics, and the blends or coextrusion products thereof. The synthetic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents.
[0008] It is within the purview of the present invention that the fill yarns comprise a varying degree of elasticity. For instance, it has been contemplated that the fills yarns located proximal to the outer edges comprise greater elasticity than those fill yarns located distal to the outer edges of the net. The dissimilarities in the elasticity performance of the fill yarns can establish specific zones within the netting. A zone is defined as an area within the netting that is comprised of more than one chain yarn and more than one fill yarn, whereby the fill yarns have a similar elasticity performance. The netting may be comprised of two or more zones. Further, the yarns of one zone may comprise similar or dissimilar yarns than that of a second zone. Further still, the yarns of one zone may comprise similar or dissimilar topical or internal additives than that of a second zone.
[0009] The yarns of the present invention may comprise flat filaments, such as tapes, mono-filaments, or a combination thereof. The filaments may be of similar or dissimilar polymeric compositions. Suitable filaments, which may be blended in whole or part with natural or synthetic polymeric compositions, include polyamides, polyesters, polyolefins, polyvinyls, polyacrylics, and the blends or coextrusion products thereof. The synthetic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents.
[0010] It is within the purview of the present invention that the chain yarns of dissimilar elongation orientated in the first direction, establish specific zones within the netting. A zone is defined as an area within the netting that is comprised of more than one chain yarn having similar elongation performance. The netting is comprised of at least three zones, wherein the zones located proximal to the outer edges comprise a greater elongation performance than the zones located distal to the outer edges. Further, the chain yarns of one zone may comprise similar or dissimilar chain yarns than those of a second zone. Further still, the chain yarns of one zone may comprise similar or dissimilar topical or internal additives than those of a second zone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a view of a portion of a Raschel machine;
[0012] FIG. 2 is a representation of the zones within the net of the present invention while the net is in a relaxed state, which zones can be provided in differentially elongated netting;
[0013] FIG. 3 is a representation of the zones within the net of the present invention while the net is in a stretched state;
[0014] FIG. 4 is a diagrammatic view of the netting partially wrapped about a rounded bale; and
[0015] FIG. 5 is a diagrammatic view of differentially elongated netting.
DETAILED DESCRIPTION
[0016] While the present invention is susceptible of embodiment in various forms, there will hereinafter be described, presently preferred embodiments, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiments disclosed herein.
[0017] In accordance with the present invention, the expandable knit is formed on a Raschel knitting machine. The machine comprises a plurality of latch needles, a plurality of lapping belts, a yarn laying-in comb and a plurality of guide bars having needle guides thereon. The latch needles are mounted in the machine to carry out a reciprocating motion in a given plane while the lapping belts are spaced from the needles on one side of the plane, i.e., on a downstream side, for guiding pattern yarns to the needles. In addition, the laying-in comb is mounted on the same side of the plane of the latch needles as the lapping belts and carries out an orbital motion perpendicularly of the plane of the latch needles to penetrate between the pattern yarns. The guide bars with the needle guides serve to lay-in stitch yarns and are mounted on an opposite side of the plane of the latch needles from the lapping belts, i.e. on the upstream side, and oscillate at an angle to the pattern yarns.
[0018] FIG. 1 , is representative of a Raschel machine, whereby it is provided with a comb plate 1 in which a plurality of latch needles 3 are mounted for reciprocating motion along their axes 2 in a vertical plane, as viewed. As shown, the needles 3 are disposed on a bar 4 which is movable up and down.
[0019] In addition, the machine includes a plurality of lapping belts or guide bars 5 spaced from the needles 3 on one side, i.e. the downstream side, of the plane of the needles 3 for guiding pattern yarns to the needles 3 . A yarn laying-in comb 6 is also mounted on the same side of the plane 2 of the latch needles 3 in order to carry out an orbital motion perpendicularly of the plane 2 while penetrating between the pattern yarns. As indicated in chain-dotted line 7 , the orbital motion is a combined stroke and oscillating motion. The comb 6 is provided with a plurality of parallel sinkers 8 each of which carries a guide rod 9 and which has a deflecting edge 10 at the forward end extending towards the plane 2 . In addition, each sinker 8 has a yarn catch 11 at a lower region of the deflecting edge 10 below the guide rod 9 . A trace comb 12 is also mounted over the comb plate 1 in known manner.
[0020] The machine also has a plurality of guide bars 13 which have needle guides thereon for directing stitch yarns to the latch needles 3 . As shown, the guide bars 13 are mounted on the side of the plane 2 of the latch needles 3 opposite the lapping belts 5 , i.e., on the upstream side. Suitable means are also provided for oscillating the guide bars 13 at an angle to the pattern yarns.
[0021] As shown in FIG. 1 , the lapping belts 5 are positioned at an acute angle downstream of the plane 2 . A yarn guide 14 is also disposed between the belts 5 and the guide bars 13 for deflecting the pattern yarns upon laying-in of the stitch yarns. This yarn guide 14 is used for laying the pattern yarns in the needle lanes (not shown). The yarn guide 14 may be coupled to the guide bars 13 so as to move therewith or may be provided with an independent drive (not shown).
[0022] The netting of the present invention is knitted on such a machine, wherein in one form a plurality of chain yarns are orientated in a first direction and a plurality of elastomeric fill yarns are orientated in a second direction. Elastomeric fill yarns may be utilized in entirety or in part throughout the net. Further, the elastic fill yarns may be of varying degrees of elasticity. It is also in the purview that the net comprise zones, wherein a zone is characterized by its degree of elasticity or complete lack thereof. The chain yarns are interconnected with fill yarns orientated in a second direction on a Raschel machine forming a net, wherein the net exhibits the ability to expand in the cross-direction.
[0023] In another form of the invention, the netting of the present invention is knitted on such a machine, wherein at least three chain yarns of a first elongation performance are orientated in a first direction and at least two chain yarns of a second elongation performance orientated in said first direction. The chain yarns of a first elongation performance are arranged into two zones, wherein each zone is located proximal to an outer edge. Chain yarns of a said second elongation performance are arranged into a separate zone and the zone is located distal to the outer edges or intermediate the two proximal zones. The chain yarns are interconnected with fill yarns orientated in a second direction on a Raschel machine forming a net, wherein the net exhibits differential elongation.
[0024] Referring to FIG. 2 therein is a diagrammatic representation of the knitted net of the present invention in a relaxed state. In one form, the net of FIG. 2 comprises three zones, wherein zone one (Z 1 ) has a greater elasticity performance than zone two (Z 2 ) and zone three (Z 3 ) has a greater elasticity performance than zone two (Z 2 ). Upon stretching, the net exhibits differential expansion in the cross-direction. It's in the purview of the present invention that the yarns of one zone may comprise similar or dissimilar yarns than that of a second zone. Further still, the yarns of one zone may comprise similar or dissimilar topical or internal additives than yarns of a second zone.
[0025] In another form, the net comprises at least three zones, wherein zone one (Z 1 ) has a greater elongation performance than zone two (Z 2 ) and zone three (Z 3 ) has a greater elongation performance than zone two (Z 2 ). Preferably, the zones located most proximal to the outer edges have an elongation performance at least 110% greater, more preferably 120% greater, and most preferably 130% greater than the zone(s) located distal to the outer edges.
[0026] FIG. 3 shows the netting once it is stretched. Due to the elasticity of the fill yarns, the net is able to expand in the cross-direction, easily conforming to the shape of a rolled bale and folding over the edges of the bale so as to prevent the bale from becoming disheveled along the ends. FIG. 4 demonstrates how the expandable net fits around the bale to keep it compact and neat.
[0027] It is within the purview of the present invention that the chain yarns of one zone may comprise similar or dissimilar chain yarns than those of a second zone. Further still, the chain yarns of one zone may comprise similar or dissimilar topical or internal additives than those of a second zone. It's also in the purview of the present invention that the fill yarns of one zone may comprise similar or dissimilar fill yarns than that of a second zone. Further still, the fill yarns of one zone may comprise similar or dissimilar topical or internal additives than fill yarns of a second zone.
[0028] FIG. 3 shows the necking that occurs once the netting is stretched. Due to the increase in elongation of the yarns located along the outer edges, the final net construct is capable of wrapping over the edges of the bale so as to prevent the bale from becoming disheveled along the ends. FIG. 4 demonstrates how the differentially elongated net fits around the bale to keep it compact and neat.
[0029] Subsequent to formation, the knitted net material may optionally be subjected to various chemical and/or mechanical post-treatments. The net material is then collected and packaged in a continuous form, such as in a roll form, or alternatively, the net material may comprise a series of weak points whereby desired lengths of twine material may be detracted from the remainder of the continuous packaged form.
[0030] From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims. | The present invention is directed to a knitted net, and more specifically to an expandable knitted net. In one form, the net comprises a plurality of fill yarns with an elastomeric performance, which allows the net to expand in the cross-direction. In another form, the present invention is directed to a netting, and more specifically to a knitted netting comprising a plurality of chain yarns with dissimilar elongation performance oriented in a first direction, and a plurality of fill yarns oriented in a second direction, wherein the yarns oriented in the second direction secure the yarns oriented in the first direction in position within the netting. | 3 |
BACKGROUND OF THE INVENTION
[0001] The span lengths of a traditional short span bridge is limited by the length of the bridge's beams and/or girders. For an existing bridge, when a length extension of a span is needed, the traditional solution is to replace the existing span or bridge with a new, longer span or bridge. This invention, instead, could provide longer spans by relocating traditional substructure supports from the traditional beam support locations to the desired longitudinally offset locations. Therefore, the same beams/girders provide a longer bridge span with shorter beam/girder lengths or smaller member sections. This invention increases the bridge span length, opening between substructures, or lateral underclearance of either a new or existing bridge (or span) by constructing this “longitudinally offset bridge substructure support system” while saving in construction cost as well as construction time.
[0002] When a facility underneath a grade separation overpass bridge or similar structures must be expanded or widened, it is always difficult and expensive using traditional methods to rebuild the structure with longer beams or girders. The underneath existing supporting substructures (piers or abutments) limit the expansion/widening of the facility.
SUMMARY OF THE INVENTION
[0003] This invention is to resolve the above-discussed problems. To construct a bridge using this invention, the offset support substructures (configured with any acceptable construction material) and their corresponding foundations are constructed at desired longitudinal offset locations away from conventional beam support pier/abutment locations. This invention provides the extra lateral underclearance, opening, or span length between bridge substructures to meet the needs of the facility below the span. In addition, a link-support system is necessary to support the bridge beams (with shorter lengths and/or weaker sections than traditionally designed beams) at an offset distance to the offset support. This invention can be used for new-construction, retrofitting, or rehabilitation of bridge structures. This invention can also utilize any applicable construction materials, such as: structural steel, CIP or pre-cast concrete, pre- or post-tensioned pre-stressed concrete, fiber reinforced polymer (FRP) composites, etc.
[0004] The procedure to construct “longitudinally offset bridge substructure support system” varies, depending on site conditions and/or other requirements. One approach, with various types of construction materials, such as: structural steel, pre-tensioned/post-tensioned pre-stressed concrete, FRP composites, or a combination, etc., the pier cap beam or similar configurations can be constructed either “below” (if there is sufficient vertical clearance) or “integrally” within the bridge superstructure. If the pier cap is an integral cap, the depth of the cap beam is about the same as that of the bridge beam or girder at the cap location; therefore, the cap beam does not reduce or limit the bridge's vertical underclearance. At the least, one substructure support, such as a super-column (concrete, steel or any applicable construction material), on each side of the bridge superstructure needs to be constructed as the “offset supports” at desirable locations offset longitudinally (or offset both ways: longitudinally & transversely). The support super-columns could be either vertical or slanted to reduce bending. This offset support combines a “link-support system”, of cable, tension tie-rods, framing, cantilever, or a combination, etc. of any construction material, to support the cap beam from the offset supports, which in term supports the bridge's superstructure. If the offset distance is large, it is possible to use tie-downs and/or counter-weights (an adjacent substructure could be used as counter-weights) to reduce the large cantilever force applying to the offset support of super-column and its foundation.
[0005] Another way to construct the longitudinally offset substructure support is to construct the “offset supports” at the desired locations in the forms of walls, columns, beam/column framing, or a combination, etc. At the traditional beam support location, where the traditional substructure is eliminated, construct beam-to-beam connections to provide continuity of the bridge span for the case of simple spans, or strengthen/modify the continuous span beams. At the other traditional beam-end location(s), construct tie-downs and/or counter weights to counteract the extra cantilever or negative moment forces as required.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The following drawings with reference numbers and exemplary embodiments are referred for explanation purposes:
[0007] FIG. 1 illustrates the elevation view of a new bridge constructed using this invention;
[0008] FIG. 2A shows the elevation view of a multi-span bridge constructed by using traditional method;
[0009] FIG. 2B illustrates the existing bridge of FIG. 2A modified using this invention, that the underpass four-lane road is widened into a six-lane road;
[0010] FIG. 3A shows the elevation view of a single span bridge constructed using traditional method;
[0011] FIG. 3B illustrates the existing bridge of FIG. 3A modified using this invention, that the underpass four-lane road is widened into a six-lane road;
[0012] FIG. 4 illustrates elevation view of another embodiment of a link-support system where a steel frame instead of cable being used;
[0013] FIG. 5A illustrates the elevation view of a link-support system where a cantilever instead of cable being used;
[0014] FIG. 5B illustrates the section view of the link-support system of FIG. 5A ;
[0015] FIG. 6 illustrates the elevation view of the link-support system where multi cables being used;
[0016] FIG. 7A shows an elevation view of a bridge span constructed by using traditional method;
[0017] FIG. 7B illustrates the existing bridge span of FIG. 7A modified using this invention. It shows another way to construct the offset support system. For this example, bridge beam connections, tie-downs & counter weights are provided as required.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring to FIG. 1 , a new bridge is implemented with this invention having one super-column ( 102 ) on each side of the bridge as the longitudinally offset substructure supports. The super-columns, which offset longitudinally from beam-end (or beam support) locations, in this case are located at the center of the bridge. The link-support system is made up of cables ( 104 , 106 ) anchored at top of super-columns and extended down to support the integral cap beams. One end of each cable is anchored to support one end of each cap beam ( 108 , 110 ), and the other end of each cable is anchored near the top of the super-columns so that the cables can support at offset distances the cap beams that support the weight of the bridge's spans. Without using this arrangement of using the super-column, cable, and integral cap beam as the longitudinal offset substructure support components, this bridge requires more supporting piers underneath, which will take up more space, reduce the span lengths or opening between substructures, and limit the lateral underclearance that can be used below the bridge.
[0019] Overall, when using this invention to construct a new bridge or modify an existing bridge, it can be described in following detail steps: First, for the pier (or other substructure), one can build the longitudinally offset supports with their foundations at desired locations of the bridge. Second, one can provide temporary supports for the bridge's superstructure and construct new integral cap beams. If post-tensioned, pre-stressed concrete is used for the cap beams, one must wait for the concrete to reach design strength before applying the post-tensioning. Third, one can install the link-support system composed of cables, tension tie-rods, steel or concrete frames, or a combination, etc. to support the superstructure at offset distance from the offset support. Lastly, one can remove the temporary supports. Referring back to FIG. 1 , compared to a traditional pier (or substructure) supporting system, this invention provides extra wide openings between the center “offset support” super-columns and the adjacent piers.
[0020] The new bridge construction example shown in FIG. 1 uses pre-cast, pre-stressed concrete beams at near-limit transportation lengths. The set of pre-stressed concrete bridge beams in the middle and centered at super-columns, are supported by the integral cap beams at both ends. This set of bridge beams provide bearing notches as seats for the adjacent sets of pre-stressed concrete bridge beams to bear on and/or tied to the integral cap beams. Besides, to achieve “wider than extra wide” openings for the two center spans, one can use two sets of pre-stressed concrete bridge beams end-to-end in the middle, one set each on each side of the super-column. In addition, it requires a structural support component, between the two mid super-columns, to support the beam ends where the two sets of pre-stressed concrete beam ends meet, in the middle at super-column location.
[0021] FIG. 2A shows a grade separation overpass bridge ( 212 ) crossing over a four-lane road. The drawing shows the elevation view of a three span continuous multi-beam bridge. This bridge has two piers ( 214 , 216 ). The road below has outside shoulders ( 218 , 220 ). When it is necessary to widen the road, it is expensive and difficult to achieve the goal using traditional methods.
[0022] However, FIG. 2B illustrates how this invention can achieve the goal of widening the underpass road below the existing bridge of FIG. 2A . First, one must construct the pier offset support super-columns ( 222 , 224 ) at the desired locations that provide sufficient space for the underpass road widening. Next, integral cap beams ( 228 , 230 ) must be constructed above the existing piers. Finally, the link-support system cables ( 232 ) must be installed by anchoring one end of each cable near the top of the super-columns ( 222 , 224 ), extending down the cables and anchoring the other ends of the cables: some to the exterior sides of super-columns to abutments ( 226 ) and the others to the interior mid-span side to cap beams ( 228 , 230 ). Once these cables are properly anchored, the existing piers, as temporary supports during construction, can be demolished. By eliminating existing piers underneath the superstructure, the existing 4-lane road has sufficient space to be widened into a six-lane road with full-width shoulders.
[0023] Here is a more detailed description of the above example. First, the longitudinally offset supports of super-columns ( 222 , 224 ) and their foundations must be constructed at the desirable locations by using the existing piers as temporary supports. Second, one must construct the integral cap beams ( 228 , 230 ). If post-tensioned, pre-stressed concrete would be used for the cap beam, one must wait for the concrete to reach design strength before applying the post-tensioning. Third, the link-support system must be installed as follows: cables ( 232 ) must be installed to support the cap beams from the offset support super-columns. Lastly, the existing pier structures can be demolished. This invention provides “extra lanes with full shoulders” for roadway below the bridge, thus avoiding replacing the bridge spans or even the entire bridge structure, and saving construction cost, construction time, and ultimately reducing traffic interruptions.
[0024] FIG. 3A shows another example of a grade separation overpass bridge crossing over a four-lane road. The drawing shows the elevation view of a single span multi-beam bridge. To widen the existing road below the bridge, it is necessary to extend the span, as well as the total length of the bridge. Using the traditional method, this procedure requires total replacement of the entire bridge (both super and sub-structures). FIG. 3B illustrates the elevation view of the rebuilt bridge implemented with this invention. First, the longitudinally offset supports of new abutments with super-columns ( 332 , 334 ) must be constructed, and their foundations placed at desirable locations behind the existing abutments, where the existing abutments ( 346 , 348 ) may act as temporary supports. (For maintaining the traffic on the overpass, provide temporary spans over the new abutment construction areas.) Second, the integral cap beams ( 350 ) must be constructed. If post-tensioned pre-stressed concrete is the choice for the cap beams, one must wait for the concrete to reach design strength before applying post-tensioning. Third, the sets of extension beams ( 336 , 338 ) are installed spanning between: the existing beam ends above existing abutments and the new abutments. This increases the total span/bridge length. Near the tops of the new abutment super-columns ( 332 , 334 ), one must install the sets of cables ( 338 , 342 ) and extend to the new abutment foundations as counter-weights; and one must install the other sets of cables ( 340 , 344 ) and extend to support the new cap beams. Lastly, the existing abutment structures ( 346 , 348 ) can be demolished, and the road can be widened below the bridge to accommodate additional traffic lanes with full shoulders.
[0025] FIG. 4 illustrates another configuration of a link-support system of this invention. Instead of using cables to support the new cap beam ( 450 ), a steel frame ( 446 , 448 , 452 ) or any similar framing system built by any material with satisfying specifications can be used.
[0026] FIG. 5A illustrates another configuration of a link-support system of this invention. Instead of using cables to support the new cap beam ( 562 ), a concrete cantilever ( 558 ) or any similar cantilever system built by any material with satisfying specifications can be used. FIG. 5B , illustrates the cross section view of FIG. 5A example. As shown in FIG. 5A , the cantilever ( 558 ) is an extended part from the offset support of super-column ( 556 ), where the new cap beams ( 562 ) are seated. FIG. 5B section view shows how the cap beam ( 562 ) can be extended and seated on top of the cantilever ( 558 ).
[0027] FIG. 6 illustrates another configuration of a link-support system of this invention. Instead of using one new cap beam, one can use one cap beam ( 676 , 678 ) on each set of the beam-ends of bridge span, where the two sets of beams of bridge span meet and where the traditional pier support is removed and replaced with offset support at a desired offset location. This link-support system uses multi-cables ( 672 , 674 ) to support individual cap beams ( 676 , 678 ). Beam-to-beam connections could be installed to provide a better continuity of the span. This multi-cable link support system could be substituted with any similar multi-cable system built by any material with satisfying specifications.
[0028] FIG. 7A illustrates an example, which shows one span of a multi-span traditional bridge with two supporting piers ( 780 , 782 ) one at each end of beam of the span. FIG. 7B shows the pier ( 782 ) is necessary to be demolished for providing additional space for the adjacent span under the bridge. A longitudinally offset support substructure ( 790 ) is constructed at a desired offset location closer to pier ( 780 ) than the original configuration. The offset support could be a concrete wall, a concrete frame, a steel frame, a combination, etc. or any form or any construction material with sufficient strength and that meets the construction specifications. The new configuration changes the action of the existing bridge beams in the span. It creates a cantilever (or large negative moment and shear forces, for the case of continuous beam/girder) for the beam ( 792 ) over the new offset support ( 790 ). Therefore it is likely these beams ( 792 ) need to be modified or strengthened. At the original pier ( 782 ) location, the support for the adjacent span is demolished. Consequently, connections ( 788 ) tying the ends of cantilever ( 792 ) with the adjacent set of bridge span beams are necessary to provide the continuity (except for the case with continuous beam/girder). Furthermore, the extra load over the new substructure ( 790 ), from the adjacent set of bridge span beams for the case of cantilever or increased span length for the case with continuous beam/girder, may create an uplift load at the other beam end of the bridge span above pier ( 780 ). Tie-downs ( 786 ) and/or counter-weights ( 784 ) are constructed to counter-act the uplift as required | This invention provides a novel construction method to longitudinally offset a traditional bridge substructure to a desired location by utilizing unconventional link-support or alternative support systems. This invention describes an approach to achieve longer span length, wider opening and/or greater lateral underclearance for the needed facility below a bridge span that no other traditional bridge construction methods could provide. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Pursuant to 35 U.S.C. §119 and the Paris Convention Treaty, this application claims the benefit of Chinese Patent Application No. 201510640081.6 filed Oct. 8, 2015, the contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The invention relates to a method for preparing a bacterial agent for removing ammonia in water.
[0004] Description of the Related Art
[0005] Conventional biological processes of nitrogen removal include nitrification and denitrification, which cannot happen synchronously because the nitrification needs oxygen and the denitrification excludes oxygen. A two-stage biological nitrogen removal process is costly, energy-consuming, and complex for operation.
[0006] In addition, metabolites produced by bacteria during the cultivation of a mixed bacterial culture comprising nitrifying bacteria and denitrifying bacteria cannot be discharged timely, which inhibits mass reproduction of the mixed culture.
SUMMARY OF THE INVENTION
[0007] In view of the above-described problems, it is one objective of the invention to provide a method for preparing a bacterial agent comprising nitrifying bacteria and aerobic denitrifying bacteria.
[0008] Using the method, the nitrifying bacteria and the aerobic denitrifying bacteria can be synchronously cultured at an optimal growth status, and then are prepared to yield a mixed microbial agent for ammonia-nitrogen removal.
[0009] To achieve the above objective, in accordance with one embodiment of the invention, there is provided a method for preparing a mixed nitrifying bacterial and denitrifying bacterial agent.
[0010] The method comprises:
[0011] 1) activating a mixed microbial preparation comprising heterotrophic nitrification bacteria and aerobic denitrification bacteria;
2) inoculating the microbial preparation comprising the nitrification bacteria and aerobic denitrification bacteria to a membrane region comprising a double-layered filler; 3) introducing a culture solution of the microbial preparation to the membrane region from one side of the membrane region at a certain pressure and a certain flow rate to cultivate bacteria and discharging metabolites produced by the microbial preparation from the other side of the membrane region; 4) centrifuging a bacterial liquid obtained from cultivation to yield a concentrated bacterial suspension; and 5) adding a protecting agent to the concentrated bacterial suspension, uniformly dry spraying a resulting mixture to a sterilized carrier to yield a denitrifying bacterial agent, and sealing the denitrifying bacterial agent for storage.
[0016] The double-layered filler allows the culture solution and the metabolite produced by the microbial preparation to pass through and prevent the microbial preparation from penetrating. The culture solution comprises: between 20 and 26 parts by weight of CH 3 COONa, between 22 and 25 parts by weight of Na 2 CO 3 , between 12 and 15 parts by weight of NH 4 Cl, between 0.05 and 1.0 parts by weight of FeSO 4 , between 3 and 5 parts by weight of MgSO 4 .7H 2 O, and between 380 and 500 parts by weight of a phosphate buffer. The phosphate buffer is prepared by K 2 HPO 3 and KH 2 PO 4 according to a weight ratio of 3:1.
[0017] In a class of this embodiment, the microbial preparation is a mixture of heterotrophic nitrifying bacteria and the aerobic denitrifying bacteria.
[0018] In a class of this embodiment, the certain pressure applied on the culture solution is between 0.01 and 0.05 megapascal. The certain flow rate of the culture solution is equivalent to that the culture solution flows into the membrane region in a unit time accounts for between 0.002 and 0.003 fold of a total volume of the culture solution within the membrane region.
[0019] In a class of this embodiment, the activation of the microbial preparation comprising the aerobic denitrification bacteria comprises: inoculating 10 parts by weight of the mixed microbial preparation comprising the heterotrophic nitrifying bacteria and the aerobic denitrifying bacteria into an 800 mL conical flask containing 150 mL of a sterilized water, shaking the microbial preparation comprising heterotrophic nitrifying bacteria and the aerobic denitrification bacteria at a rotational speed of 220 rpm for between 2.5 and 3 hrs, and discarding an original carrier.
[0020] In a class of this embodiment, a temperature of the cultivation process is controlled at between 29 and 32° C.
[0021] In a class of this embodiment, a pH value of the culture solution is controlled at between 7.0 and 8.0. Too high or too low of the pH value is not beneficial for the growth of the bacteria.
[0022] In a class of this embodiment, a concentration of a dissolved oxygen in the culture solution is between 0.6 and 0.8 mg/L. When the concentration of the dissolved oxygen is lower than 0.6 mg/L, the growth of the nitrifying bacteria becomes slow, and too high of the concentration of the dissolved oxygen results in surplus.
[0023] In a class of this embodiment, the centrifuging is conducted at a rotational speed of between 2000 and 2300 rpm for 15 min.
[0024] In a class of this embodiment, the protecting agent is a mixture of 0.8 percent by weight of glycine and 2.0 percent by weight of glycerin according to a ratio of glycine to glycerin of between 1:2 and 1:3; and an addition of the protecting agent is between 2.2 and 3.6 folds of the concentrated bacterial suspension.
[0025] In a class of this embodiment, the carrier is calcium alginate, a diatomite, or a rice bran.
[0026] Advantages of the method for preparing the mixed bacterial agent for removing ammonia-nitrogen according to embodiments of the invention are summarized as follows: the heterotrophic nitrifying bacteria and the aerobic denitrifying bacteria are inoculated in the membrane region comprising a double-layered filler for mixed cultivation. The culture solution is introduced to the membrane region from one side of the membrane region at a certain pressure and a certain flow rate to supply the growth of the bacteria and to carrier away the bacterial metabolite from the other side of the membrane region. In the meanwhile, the heterotrophic nitrifying bacteria supply aerobic denitrification bacteria with nitrate nitrogen necessitated for the growth of the aerobic denitrification bacteria, and the aerobic denitrification bacteria remove the growing obstacles for the heterotrophic nitrifying bacteria, so that both the nitrifying bacteria and the denitrifying bacteria are in the optimal growing status, realizing concentrated cultivation of the bacteria and the production of the bacterial agent that is easily preserved after amplifying cultivation. After long term preservation, the mixed bacterial agent for removing ammonia-nitrogen still works effectively in degrading ammonia-nitrogen and possesses good reproduction and activation properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The invention is described hereinbelow with reference to accompanying drawings, in which the sole figure is a chart showing removal effect of ammonia-nitrogen of a denitrifying bacterial agent in accordance with one embodiment of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0028] For further illustrating the invention, experiments detailing a method for preparing a mixed nitrifying bacterial and denitrifying bacterial agent are described below. It should be noted that the following examples are intended to describe and not to limit the invention.
Example 1
[0029] A method for preparing a bacterial agent for removing ammonia-nitrogen was conducted as follows: 10 parts by weight of a mixed bacterial culture of nitrifying bacteria and aerobic denitrifying bacteria was inoculated into an 800 mL of a conic flask containing 150 mL of a sterilized water and shaken at a rotational speed of 220 rpm for activation for 2.5 hrs. Thereafter, an original carrier was discarded and the mixed bacterial culture was inoculated into a membrane region comprising a double-layered filler. The filler was a hollow fiber membrane in a planar shape, and a thickness of the filler was 0.1 mm. The double-layered filler allowed a culture solution and bacterial metabolites to pass through and prevented the bacteria from passing through. The culture solution flowed into the membrane region from one side of the membrane region at a pressure of 0.01 megapascal at a certain flow rate. The flow rate was equivalent to that the culture solution entering the membrane region in a unit time was 0.002 fold of a total volume of the culture solution in the membrane region. The culture solution was adapted to supply the bacteria with nutrition for growth and to carry the bacterial metabolites out of the membrane region from the other side of the membrane region. Concentrated cultivation of the bacteria was performed at a temperature of 29° C. and a pH value of 7.0. Too high or too low of the pH value was not beneficial for the growth of the bacteria. The concentration of the dissolved oxygen in the culture solution was 0.6 mg/L. When the concentration of the dissolved oxygen is lower than 0.6 mg/L, the growth of the nitrifying bacteria was slow, and too high the concentration of the dissolved oxygen resulted in surplus. The bacteria solution after cultivation was then centrifuged at the rotational speed of 2000 rpm for 15 min, and the bacteria were separated to prepare a concentrated bacterial suspension. 0.8 percent by weight of glycine and 2.0 percent by weight of glycerin were mixed according to a weight ratio of glycine to glycerin of 1:2 to prepare a protecting agent and the protecting agent was then added to the concentrated bacterial suspension, in which an addition of the protecting agent was 2.2 folds of the concentrated bacterial suspension. The resulting mixture was uniformly loaded on sterilized calcium alginate as a carrier by dry spraying to yield the denitrifying bacterial agent, in which, a water content of the carrier was controlled equal to or less than 12 percent by weight. The yielded bacterial agent was sealed for storage. The culture solution comprised: 20 parts by weight of CH 3 COONa, 22 parts by weight of Na 2 CO 3 , 12 parts by weight of NH 4 Cl, 0.05 parts by weight of FeSO 4 , 3 parts by weight of MgSO 4 .7H 2 O, and 380 parts by weight of a phosphate buffer. The phosphate buffer was prepared by K 2 HPO 3 and KH 2 PO 4 in a weight ratio of 3:1.
Example 2
[0030] A method for preparing a bacterial agent for removing ammonia-nitrogen was conducted as follows: 10 parts by weight of a mixed bacterial culture of nitrifying bacteria and aerobic denitrifying bacteria was inoculated into an 800 mL of a conic flask containing 150 mL of a sterilized water and shaken at a rotational speed of 220 rpm for activation for 2.75 hrs. Thereafter, an original carrier was discarded and the mixed bacterial culture was inoculated into a membrane region comprising a double-layered filler. The filler was a hollow fiber membrane in a tubular shape, and a thickness of the filler was 0.55 mm. The double-layered filler allowed a culture solution and bacterial metabolites to pass through and prevented the bacteria from passing through. The culture solution flowed into the membrane region from one side of the membrane region at a pressure of 0.03 megapascal at a certain flow rate. The flow rate was equivalent to that the culture solution entering the membrane region in a unit time was 0.0025 fold of a total volume of the culture solution in the membrane region. The culture solution was adapted to supply the bacteria with nutrition for growth and to carry the bacterial metabolites out of the membrane region from the other side of the membrane region. Concentrated cultivation of the bacteria was performed at a temperature of 30.5° C. and a pH value of 7.5. Too high or too low of the pH value was not beneficial for the growth of the bacteria. The concentration of the dissolved oxygen in the culture solution was 0.7 mg/L. When the concentration of the dissolved oxygen is lower than 0.6 mg/L, the growth of the nitrifying bacteria was slow, and too high the concentration of the dissolved oxygen resulted in surplus. The bacteria solution after cultivation was then centrifuged at the rotational speed of 2150 rpm for 15 min, and the bacteria were separated to prepare a concentrated bacterial suspension. 0.8 percent by weight of glycine and 2.0 percent by weight of glycerin were mixed according to a weight ratio of glycine to glycerin of 1:2.5 to prepare a protecting agent and the protecting agent was then added to the concentrated bacterial suspension, in which an addition of the protecting agent was 2.9 folds of the concentrated bacterial suspension. The resulting mixture was uniformly loaded on a sterilized diatomite as a carrier by dry spraying to yield the denitrifying bacterial agent, in which, a water content of the carrier was controlled less than or equal to 13.5 percent by weight. The yielded denitrifying bacterial agent was sealed for storage. The culture solution comprised: 23 parts by weight of CH 3 COONa, 23.5 parts by weight of Na 2 CO 3 , 13.5 parts by weight of NH 4 Cl, 0.525 part by weight of FeSO 4 , 4parts by weight of MgSO 4 .7H 2 O, and 420 parts by weight of a phosphate buffer. The phosphate buffer was prepared by K 2 HPO 3 and KH 2 PO 4 in a weight ratio of 3:1.
Example 3
[0031] A method for preparing a bacterial agent for removing ammonia-nitrogen was conducted as follows: 10 parts by weight of a mixed bacterial culture of nitrifying bacteria and aerobic denitrifying bacteria was inoculated into an 800 mL of a conic flask containing 150 mL of a sterilized water and shaken at a rotational speed of 220 rpm for activation for 3 hrs. Thereafter, an original carrier was discarded and the mixed bacterial culture was inoculated into a membrane region comprising a double-layered filler. The filler was a capillary membrane in a tubular shape and a thickness of the filler was 1.0 mm. The double-layered filler allowed a culture solution and bacterial metabolites to pass through and prevented the bacteria from passing through. The culture solution flowed into the membrane region from one side of the membrane region at a pressure of 0.05 megapascal at a certain flow rate. The flow rate was equivalent to that the culture solution entering the membrane region in a unit time was 0.003 fold of a total volume of the culture solution in the membrane region. The culture solution was adapted to supply the bacteria with nutrition for growth and to carry the bacterial metabolites out of the membrane region from the other side of the membrane region. Concentrated cultivation of the bacteria was performed at a temperature of 32° C. and a pH value of 8.0. Too high or too low of the pH value was not beneficial for the growth of the bacteria. The concentration of the dissolved oxygen in the culture solution was 0.8 mg/L. When the concentration of the dissolved oxygen is lower than 0.6 mg/L, the growth of the nitrifying bacteria was slow, and too high the concentration of the dissolved oxygen resulted in surplus. The bacteria solution after cultivation was then centrifuged at the rotational speed of 2300 rpm for 15 min, and the bacteria were separated to prepare a concentrated bacterial suspension. 0.8 percent by weight of glycine and 2.0 percent by weight of glycerin were mixed according to a weight ratio of glycine to glycerin of 1:3 to prepare a protecting agent and the protecting agent was then added to the concentrated bacterial suspension, in which an addition of the protecting agent was 3.6 folds of the concentrated bacterial suspension. A resulting mixture was uniformly loaded on a sterilized rice bran as a carrier by dry spraying to yield the denitrifying bacterial agent, in which, a water content of the carrier was controlled within 15 percent by weight. The yielded denitrifying bacterial agent was sealed for storage. The culture solution comprised: 26 parts by weight of CH 3 COONa, 25parts by weight of Na 2 CO 3 , 15 parts by weight of NH 4 Cl, 1.0 part by weight of FeSO 4 , 5 parts by weight of MgSO 4 .7H 2 O, and 500 parts by weight of a phosphate buffer. The phosphate buffer was prepared by K 2 HPO 3 and KH 2 PO 4 in a weight ratio of 3:1.
[0032] The heterotrophic nitrifying bacteria and the aerobic denitrifying bacteria are placed in the membrane region formed by the double-layered filler for mixed cultivation. The culture solution is introduced to the membrane region from one side of the membrane region at a certain pressure and a certain flow rate to supply the growth of the bacteria and to carrier away the bacterial metabolite from the other side of the membrane region. In the meanwhile, the heterotrophic nitrifying bacteria supply aerobic denitrifying bacteria with nitrate nitrogen necessitated by the growth of the aerobic denitrifying bacteria, and the aerobic denitrifying bacteria remove the growing obstacles for the heterotrophic nitrifying bacteria, so that both the nitrifying bacteria and the denitrifying bacteria are in best growing status, realizing concentrated cultivation of the bacteria and the production of the bacterial agent that is easily preserved after amplifying cultivation. After long term preservation, the mixed nitrifying bacterial and denitrifying bacterial agent still works effectively in degrading ammonia-nitrogen and possesses good reproduction and activation qualities. The bacteria possess good growth potential and are effective to remove ammonia-nitrogen.
[0033] Experimental Verification
[0034] The mixed bacterial agents prepared by the methods of Examples 1-3 were taken out after one-year preservation and added to three groups of the same water sample to be treated, in which a concentration of the ammonia-nitrogen was tested to be 0.24 g nitrogen per mL, for demonstrating the removal effect of the ammonia-nitrogen. Data were collected and a graph shown in the sole figure was charted, which indicates that the mixed bacterial agents have good effects in treating the water sample, and the removal rate of the ammonia-nitrogen reaches 100 percent by weight after 18 hrs.
[0035] Unless otherwise indicated, the numerical ranges involved in the invention include the end values. While particular embodiments of the 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 the 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 the invention. | A method for preparing a bacterial agent for removing ammonia-nitrogen, including: 1) activating a mixed microbial preparation including heterotrophic nitrification bacteria and aerobic denitrification bacteria; 2) inoculating the microbial preparation including heterotrophic nitrification bacteria and the aerobic denitrification bacteria to a membrane region including a double-layered filler; 3) introducing a culture solution of the microbial preparation to the membrane region from one side of the membrane region at a certain pressure and a certain flow rate to cultivate bacteria and discharging metabolites produced by the microbial preparation from the other side of the membrane region; 4) centrifuging a bacterial liquid obtained from cultivation to yield a concentrated bacterial suspension; and 5) adding a protecting agent to the concentrated bacterial suspension, uniformly dry spraying a resulting mixture to a sterilized carrier to yield a bacterial agent, and sealing the bacterial agent for storage. | 2 |
BACKGROUND OF THE INVENTION
The present invention is related to a starter apparatus for an internal combustion engine.
A starter apparatus for an internal combustion engine is known including a starter motor provided with a drive shaft; an axially shiftable starting gear engageable with the ring gear of the internal combustion engine; a drive train for transferring rotary motion of the drive shaft of the starter motor to the starting gear, the drive train having a torsional rigidity and including a plurality of parts from the starting gear to the drive shaft; a free wheel clutch coupled with the drive shaft; and a shock absorbing means for damping torque shocks between the starting gear and the drive shaft occurring on rotation of the drive shaft.
A starting device, the so-called starter of the internal combustion engine, including means for damping the compression and decompression impacts in the starter mechanism is described in U.S. Pat. No. 4,561,316. This starter has a hollow gear in a planetary gear device used as a transmission gear unit in the starter which has shock damping means in the form of a rubber pad in its housing. A free wheel clutch is used for mechanical decoupling of the starter motor and the internal combustion engine, when the engine is running and has been accelerated by the starter rotation. The periodic release and engagement of the free wheel clutch because of the piston motion in the cylinders of the internal combustion engine due to its gas torque moment is an undesirable side effect in the so-called full rotation stage, in which the internal combustion engine has been put into rotation by the starter mechanism without accelerated combustion. This periodic release and engagement of the free wheel clutch depends on the moment of inertia values of the starter and the engine acting on the gear shaft and the drive torque of the starter and on the load on the crank shaft of the internal combustion engine. Fundamentally the released phase of the free wheel clutch is longer on starting with a transmission gear unit by which the starting moment of inertia is increased than on starting without it. A longer released phase results also at higher temperatures, since then the crankshaft friction moment is reduced, while the gas torque moment of the internal combustion engine increases.
When rotational play is present in the drive train of the starter having a starting gear, the starter mechanism exhausts this rotational play during each load change on engagement of the free wheel clutch and, because of that, a shock or impact is expected on the sides of the starting gear. These impacts on the gear teeth depend on the incorrect inertial moments of the starter and the crank shaft, on the total rotational play, on the rigidity of the starter drive train, on the differences in angular speed between the ring gear of the internal combustion engine and the starting gear as well as on the drive and load on the starting gear.
The known elastic support of the hollow gear in the starter housing with a rubber cushion or with a polygonal shaped rubber body between the hollow gear and the housing wall according to European Patent Document 0 375 396 A1 is not satisfactory at least in starter mechanisms of the larger and medium size starters, since this type of damping rubber has a strongly progressive characteristic curve and thus already is much too hard during a minimal deformation. The same goes for the starter described in U.S. Pat. No. 5,127,279, in which the drive shaft of the transmission gear unit connected with the starting gear is connected with a hollow gear by an elastic connecting means made from rubber or the like for damping the torque impacts or shocks occurring in the drive train during the starting process. Furthermore these damping elements would be destroyed in the course of time in the starter apparatus of larger and medium size by the comparatively very high shocks or impacts acting on them. Starter devices of comparatively higher power predominantly are equipped without transmission gear units because of these high shock loads. Because of that, a correspondingly larger expensive starter motor must be used and the impact loads must be received by the free wheel clutch responding in a pulsating manner, whereby also a loud noise is generated.
SUMMARY OF THE INVENTION
It is an object of the present invention to damp the rotational impacts, shocks and/or load spikes occurring in a starter for an internal combustion engine of the above-described type, particularly in the full rotation stage on engagement of the free wheel clutch of the starter to reduce the wear in the starters of larger power, to reduce mechanical power loss, to reduce noise generation and to reduce the eigenfrequency of the drive train.
These objects and others which will be made more apparent hereinafter are attained in a starter apparatus for an internal combustion engine including a starter motor provided with a drive shaft; an axially shiftable starting gear engageable with the ring gear of the internal combustion engine; a drive train for transferring rotary motion of the drive shaft of the starter motor to the starting gear, the drive train having a torsional rigidity and including a plurality of parts from the starting gear to the drive shaft; a free wheel clutch coupled with the drive shaft; and a shock absorbing means for damping torque shocks between the starting gear and the drive shaft occurring on rotation of the drive shaft.
According to one feature of the present invention a shock absorber spring means is arranged in the drive train of the starter apparatus and is prestressed to provide a torque acting in the drive direction equal to from 15 to 50% of a stall torque of the starter motor at the starting gear. Furthermore the ratio of a torsional rigidity of another drive train equal to the above-described drive train but without the shock absorber spring means and at the stall torque to a torsional rigidity of the shock absorber spring means effective at the starting gear must be at least 4.
The starter with the shock absorber spring means according to the invention provides a starter apparatus of higher power and reduces the shock load occurring, especially reduces the torque peaks formed on engagement of the free wheel clutch in the full rotation stage. Because of that, transmission gear units with larger reductions can be used for the starter devices of larger power. This means that the size of the starter can be reduced while retaining the same power level by increasing the rotational speed of the starter motor. Also because of the use of prestressed spring elements the oscillations of the starter drive train are drastically reduced whereby the spring displacement can be reduced in comparison to an shock absorber spring means without prestressing. Because of that, essentially completely linear response spring elements can be used in the shock absorber spring means according to the invention instead of the known rubber cushion as the damping elements, if necessary in a housing having the same dimensions as in the prior art starter. An additional substantial advantage is a definite reduction of the eigenfrequency of the starter drive train because of the shock absorber spring means according to the invention and, because of that, the desired damping of noise and shocks. It is also advantageous that the wear originating from the hard rotational shocks at the free wheel clutch and the teeth of the gears is now reduced.
A considerable advantage is provided according to the invention by the greatly reduced torque increase during the damping of the shocks by the coarse thread in the drive train; also there is a reduced axial force component which allows reduction of the pitch of the coarse thread and thus the meshing process occurs easier, for example with higher friction at a sticking starting gear sleeve. Furthermore a reduced coarse thread pitch has the advantage that in the catch up stage a reduced disengagement and thus reduced axial shocks occur during engagement of the free wheel clutch, which has the result that noise generation is substantially reduced.
Various embodiments of the starter according to the invention are possible. It is particular advantageous, when the drive train between the starter motor and the free wheel clutch contains a transmission gear unit so that the spring elements of the shock absorber spring means can engage on the transmission gear means and/or on the free wheel clutch. For noise damping and wear reduction it is especially appropriate to reduce the eigenfrequency of the rotary oscillations of the drive train by changing the spring stiffness of the shock absorber spring means to less than half that of the eigenfrequency without the shock absorber spring means.
A particularly desirable arrangement of the shock absorber spring means results, when it engages on the transmission gear unit of the drive train, particularly at the largest radial positions in the transmission gear unit, since there the shock load of the pretensioned shock absorber spring means is least. Thus it is particularly advantageous when the shock absorber spring means is mounted between a hollow gear of the planetary gears of the transmission gear unit and a housing-fixed part of the housing of the starter. There is then sufficient space available to form the shock absorber spring means from a plurality of spring elements engaged circumferentially on the hollow gear, which are braced on the housing-fixed housing part. The shock energy is distributed equally on the individual spring elements, which can be accordingly designed for a larger spring displacement and for smaller spring forces.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects, features and advantages of the present invention will now be illustrated in more detail by the following detailed description, reference being made to the accompanying drawing in which:
FIG . 1 is a partially side elevational, partially detailed cross-sectional view of one embodiment of a starter apparatus according to the invention with a shock absorber spring device and planetary gear;
FIG. 2 is a cross-sectional view through the planetary gear from the embodiment of FIG. 1 with three coil springs between the housing and the hollow gear;
FIG. 3 is a graphical illustration of the relationships between rotation speed at the free wheel clutch of a) a starter of the prior art and b) a similar starter according to the invention;
FIG. 4 is a graphical illustration of the rigidity of the starter drive train showing rotation angle versus torque at the ring gear;
FIG. 5 is a cross-sectional view through a planetary gear showing a meandering curved leaf spring acting as the shock absorber spring element between the housing and the hollow gear in another embodiment of the invention;
FIG. 6 is a perspective view of a meandering curved leaf spring acting as shock absorber spring element in the hollow gear received in the housing;
FIG. 7 is a cross-sectional view through a planetary gear with two leaf springs as shown in FIG. 6 between the hollow gear and the housing;
FIG. 8 is a partially side elevational, partially detailed cross-sectional view of another embodiment of a starter apparatus according to the invention with a leg spring set;
FIG. 9 is a plan view of a spring segment with a hook from the apparatus shown in FIG. 8;
FIG. 10 is a cross-sectional view through two connected spring segments according to FIG. 9 taken along the section line X--X of FIG. 9(which shows only one of the spring segments);
FIG. 11 is a cutaway plan view of a portion of a spring segment showing catch element and recess at respective ends of opposing spring legs;
FIG. 12 is a cross-sectional view of two connected spring segments according to FIG. 11 taken along the section line XII--XII(FIG. 11 showing only one of the spring segments);
FIG. 13 is a cutaway cross-sectional view of a part of the drive train of a starter according to the invention with transmission gear;
FIG. 14 is a cross-sectional view through the transmission gear unit showing three coil springs acting as shock absorber spring means between the planetary gears and transmission gear shaft of the transmission gear unit of FIG. 13 in an additional embodiment of the invention;
FIG. 15 is a partially side, partially longitudinal cross-sectional view through an embodiment with a shock absorber spring means between a free wheel clutch hub and starting gear; and
FIG. 16 is a partially front view, partially cutaway cross-sectional view through the free wheel clutch shown in FIG. 15.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A starter according to the invention is shown in FIG. 1. It contains a direct current motor acting as starter motor 11, whose armature 12 is connected by an armature shaft 13 with transmission gear unit 14. A hollow gear 15 of the transmission gear unit 14 is accommodated in the housing 16 of the starter 10 and a planet gear support 17 is rigidly connected with a transmission gear shaft 18 of the transmission gear unit 14. The transmission gear shaft 18 is connected by an unshown coarse thread in a known way in operation with a carrier shaft 19 of a free wheel clutch 20 having a hub 21. The hub 21 of the free wheel clutch 20 is connected rigidly with a starting gear 22. For starting the internal combustion engine the starting gear 22 is advanced by a starter lever 24 driven by a starter relay 23 so that the starting gear 22 engages in a ring gear 25 of the internal combustion engine and rotates via the free wheel clutch 20 and the carrier shaft 19 because of the course thread connection. The starter lever 24 engages with its lower end in a guide ring 26, which bears by a meshing spring 27 against the housing of the free wheel clutch 20. The entire assembly of rotating parts from the starting gear 22 to the rotor or armature 12 of the starter motor forms a starter drive train 100 with an inertial moment or inertia determined by the mass of the rotating parts, which in the case of the transmission gear containing starter is essentially smaller than the starter with the starter drive train.
Because of different accelerations and different peripheral speeds during the starting process shocks or impacts occur between the starting gear 22 and the transmission gear shaft 18, which depending on the abruptness of the impact and the maximum impact moment act more or less strongly mechanically and dynamically on the parts in the drive train of the starter 10. This is particularly the case in the so-called full rotation stage, when after releasing the free wheel clutch 20 in catching up with the starter mechanism the free wheel clutch releases and engages many times, before the internal combustion engine is rotated again by the starter device in a so-called compression stage.
A shock absorber spring means 28 is arranged in the drive train 100 between the starting gear 22 and the drive shaft 13 of the starter motor 11. The shock absorber spring means 28 is arranged here in the transmission gear unit 14 of the drive train, and is inserted between the hollow gear 15 of the planetary gear unit and a part of the housing 16 provided as a bearing member 29 for the planetary gear.
The shock absorber spring means 28, as shown in FIG. 2, comprises a plurality of engaging shock absorber spring elements 30 distributed around the circumference of the hollow gear 15. One end of each of the spring elements 30 is braced against stationary bearing member 29 and the other end presses a radially exteriorly projecting projecting member or protruding element 31 of the hollow gear 15 with a pressure Pv acting counter to the drive torque of the drive motor against a housing stop 32, i.e. against the housing. The directional arrows shown in the planetary gear unit indicate that the gear teeth at the end of the drive shaft 13 of the starter motor engage with a clockwise rotation direction in the three planetary gears 33, which rotate in the opposite counterclockwise direction as shown in FIG. 2 on bearing pins 34 in the planet gear support 17 of the planetary gear unit and thus the drive torque is transmitted to the hollow gear 15 in a counterclockwise direction as shown in FIG. 2. The planetary gears 33 roll on the hollow gear 15 and, because of that, rotate in the opposite clockwise direction. Since the planet gear support 17 is connected by the free wheel clutch 20 with the starting gear 22, the starter has a clockwise rotating starter mechanism.
In the embodiment shown in FIG. 2 the shock absorber spring elements 30 are pretensioned coil springs 35. It is seen in FIG. 2 that the hollow gear 15 of the planetary transmission gear unit 14 is rotatable during the impacts in the drive direction against the force of the coil springs 35 about an angle β of from about 10° to 15°, limited by an additional stop element 36 formed on the periphery of the hollow gear 15, which acts as an overload protecting element, and contacts on a shoulder 37 of the bearing member 29.
The operation and dimensioning of the shock absorber spring means 28 in the starter mechanism according to the invention are more clearly explained with the aid of FIGS. 3 and 4. The starter mechanism has in this example a starter motor with 1.4 kH power. The stall torque Mk acting on the starting gear 22--for example, during attempts at starting the internal combustion engine with a drive with substantial input action--amounts to 20 Nm at the starting gear. The torsional rigidity constant C St0 of the drive train 100 of the starter 10 amounts to about 700 Nm rad without the shock absorber spring means 28 on the starting gear side.
FIG. 3 shows two time courses a) and b) of the gear rotation speed n R as a solid line and the rotation speed n F1 at the carrier shaft 19 as a dashed line for two different situations. The time dependence curve a) is for a starter which has the same structure as the starter of the invention shown here but does not have the shock absorber spring means 28 of the invention. In this case at the beginning of the decompression stage in a cylinder of the internal combustion engine the starting gear 22 driving the ring gear 25 of the engine releases the free wheel clutch 20, since it catches up with the drive motor 11 with the rotation speed n F1 . During the subsequent compression stage now the gear speed n R drops under the rotation speed n F1 , so that now the free wheel clutch 20 engages with an impact after running through the entire play of the starter device 10. After that a plurality of spike-like oscillations of the gear rotation speed occur so that the free wheel clutch 20 partially releases and closes periodically.
The situation with the shock absorber spring means 28 according to the invention is shown in case b) under case a) in FIG. 3. A nearly exactly sinusoidal oscillation with a clearly reduced wavelength occurs at time tx so that the impact on engagement of the free wheel clutch 20 at time tx is substantially damped and the multiple releasing of the coupling is reduced. Below case b) the time scale from the process is shown on time axis t. Since the increase of the gear rotation speed n R is substantially reduced on engagement of the free wheel clutch 20 at time tx, an appropriate reduction of the impact moment occurs.
The time behavior of the starter according to the invention shown in case b) in FIG. 3 is obtained because the shock absorber spring means 28 is acting with a compression torque Mv in the drive direction between the starting gear 22 and the drive shaft 13 of the starter motor, which on the starting gear side amounts to between 15 and 50 percent of the stall torque Mk of the starter motor 11 relative to gear shaft rotation. Furthermore the ratio of the torsional rigidity C St0 of a drive train formed by the parts from the starting gear 22 to the starter motor 11 but with an ineffective or absent shock absorber spring means 28 to the torsional rigidity C F of the shock absorber spring means 28 related to the stall torque Mk is from 1/4 to 1/10 advantageously.
In FIG. 4 the rotation angle φR of the drive train 100 of the starter 10 relative to the gear shaft depends on the torque M R acting on the starting gear 22. The increasing dashed curve of 1/Cst0 in FIG. 4 shows the reciprocal of the torsional rigidity of the drive train of the starter apparatus 10 without shock absorber spring means in the drive direction. The first two angular rates of the starting gear rotation are determined by the different nonlinear processes present between the ring gear 25, the clutch and the drive shaft 13. Without the shock absorber spring means 28 now a linear increase of the dashed curve occurs with increasing torque, which shows the effective torsional rigidity of the drive train. In the upper region of the dashed curve the free wheel clutch 20 engages so that the steepness of the curve increases, until it makes a full rotation to a maximum torque M max . The stall torque Mk of the starter 10 is fundamental to obtain reproducible values in the determination of the torsional rigidity C St0 , since in this region (in the straight branch of the curve) of the dashed characteristic line the torsional rigidity C St0 of the drive train has a definite constant value, which in this embodiment shown in the drawing amounts to 700 Nm/rad. The stiffness of the dot-dashed curve 1/C F shows the reciprocal of the torsional rigidity of the shock absorber spring means 28 effective at the starting gear 22. The torque Mn of the shock absorber spring means 28 effective at the starting gear due to prestressing of the spring elements amounts to 7 Nm, which is 35% of the stall torque Mk of 20 Nm. The shock absorber spring means 28 is responsive on exceeding these values. Its torsional rigidity amounts to C F =60 Nm/rad. The ratio of the torsional rigidity of the drive train 100 to the torsional rigidity of the shock absorber spring means 28 is for example given by a factor F:
F=C.sub.St0 /C.sub.F =700/60=11.66
Moreover in a normal starting process, especially in the full rotation stage, the impacts occurring on engagement of the free wheel coupling 20 are damped by the reduced torsional rigidity in the embodiment with the shock absorber spring means 28 so much that the starting gear oscillations do not reach the maximum rotation angle φ R of about 15° predetermined by the placement of the stop element 36. This maximum rotation angle necessitates a torque M Fmax of about 25 Nm related to the starting gear, which is close to the upper stall torque Mk and which is exceeded only in the case of a so-called reignition.
The actual torsional rigidity C St of the starter drive train 100 with the shock absorber spring means 28, which is shown as its reciprocal 1/Cst in FIG. 4 by the solid curve, results from the superposition of the torsional rigidity C F of the shock absorber spring means 28 with the torsional rigidity of the shock-absorber-spring-means-less starter drive train. This curve shows that in the region up to the torque Mv due to prestressing the shock absorber spring means 28 because of its tension does not respond, that in the region from Mv to M B1 the rotation of the starting gear 22 by the shock absorber spring means 28 and the drive train adds and that on attaining a blocking torque M B1 , when the stop element 36 contacts on the shoulder 39 of the bearing member 29, again the original torsional rigidity of the starter drive train 100 operates until the free wheel clutch 20 makes a full rotation with additional increasing torque.
The action of the shock absorber spring means 28 is determined by the chosen prestressing and by the spring constant C Fe of the spring elements 30 used to make up the shock absorber spring means 28. In the embodiment with the three spring elements 30 according to FIG. 2 the compression Pv=77N with a spacing to the axis 38, A=30 mm results, so that the prestressing torque Mv=3 Pv×A=7 Nm and from the spring constant C Fe =22 N/m the spring elements 30 for the shock absorber spring means 28 have a torsional rigidity C F =C Fe .3.A 2 =60 Nm/rad.
The torque Mv of the shock absorber spring means 28 due to prestressing should not be less than 15% of the stall torque Mk of the starter motor, since otherwise the required spring displacement and rotation angle for absorbing shocks or impacts in the drive direction is too large to maintain the starter compactness and since the spring elements then among other things can produce their own noise by vibrating. The torque Mv due to prestressing should also not be more than 50% of the stall torque Mk, since otherwise the shock absorber spring means 28 is acted only on a little or not at all by the shocks occurring in the normal starting process and thus the damping of the shocks does not occur.
The action of the shock absorber spring means 28 is moreover lost if the torsional rigidity constant C F is too large. The ratio F of the torsional rigidity of the starter to the torsional rigidity of the shock absorber spring means 28 is thus selected to be larger than 4. The eigenfrequency Fo St of the rotary oscillation of the drive train 100 depends on its inertial moment J St (related to the gear shaft) and its torsional rigidity constant C St0 according to the equation: ##EQU1## With unchanged moment of inertia of the starter-drive train the eigenfrequency fo St1 of the rotary oscillations of the drive train in the embodiment with the shock absorber spring means 28 are reduced to less than half of the corresponding eigenfrequency fo St without the shock absorber spring means. In the exemplary case this amounts to ##EQU2## this means less than 1/3 of the eigenfrequency of the drive train originates from the eigenfrequency of a corresponding drive train without the shock absorber spring means 28.
FIG. 5 shows an additional embodiment for a counterclockwise running transmission gear unit 14 formed as a planetary drive gear of the starter 10, in which the shock absorber spring means 28 is formed from two spring elements 30 diametrically opposite to each other. These spring elements 30 comprise meandershaped curved leaf springs 40, which are inserted as compression springs between the hollow gear 15 and the bearing member 29. The respective ends of the leaf springs 40 are clamped in a clasp-like manner between a protruding element 41 on the outer circumference of the hollow gear 15 and clamping element 42 on the bearing member 29 so that they can act in the drive direction. The hollow gear 15 is pressed with the two protruding elements 41 against respective stop elements 43 on the bearing member 29 by action of the leaf spring 40. Both of the leaf springs 40 form the shock absorber spring means 28, whose clamping moment at the starting gear 22 and torsional rigidity are determined by the strength and form of the leaf springs 40.
In FIGS. 6 and 7 another embodiment of the starter according to the invention is shown, in which two meander-form curved leaf springs 45 are positioned diametrically opposite to each other on the circumferential region of the hollow gear 15. The respective ends of each leaf spring 45 are clamped in a clasp-like manner on the clamping elements 42 and 46 on the bearing member 29. In the central region the leaf spring 45 is held on a protruding element 41 on the outer periphery of the hollow gear 15. For adjustment of the tension of the leaf spring 45 the hollow gear 15 is rotated from the neutral position of the leaf spring 45 an amount x in the drive direction and then clamped or braced on the pressing element 43 of the bearing member 29. Because of that, the leaf spring 45 acts with its region 45a in front of the pressing or stop element 43 in the direction the spring acts as a compression spring and with its region 45b to the rear of the pressing element 43 as a tension spring. The compression of the leaf spring 45 adjusts itself according to the size of the rotation angle in the direction in which contact is made.
FIGS. 8 to 12 show additional embodiments of the starter 10 according to the invention with shock absorber spring means 28 in the drive train of the starter. The shock absorber spring means 28 comprises a leg spring set 50 which is already known. FIG. 8 is a cross-sectional view of the starter of this embodiment showing the leg spring set 50 in front of the hollow gear 15 on a collar 51 of the bearing member 29 of the housing 16. The leg spring set 50 comprises a plurality of axially side-by-side spring segments 52.
FIG. 9 shows one of the spring segments 52, which is punched from a spring steel sheet and has two throughgoing holes 53 punched in it diametrically opposite each other. As shown in FIG. 10 connecting means 55 are formed on the free ends of the spring legs 54 on each side of each of the holes 53, which are engaged with connecting means 55 on adjacent or neighboring spring segments 52 of the set. Since FIG. 10 is a cross-sectional view taken along the section line X--X in FIG. 9, one sees that the free ends of the spring legs 54 are bent at right angles alternately to one or the other side (in and out of the plane of FIG. 9) to form hook elements 54a, so that the spring legs 54 on neighboring spring segments 52 engage in each other at their free ends. By bent "alternately" it is meant that the free ends on opposing spring legs 54 on the same side of the spring segment 52 are bent out of the plane of the spring segment in opposite directions. The leg spring set 50 is arranged concentrically in the transmission gear unit 14 under tension in the starter 10 so that the right end segment 52a (right end in FIG. 8) is held with the hole 53 on the pin 56 on the hollow gear 15 and the left end segment is held with its hole 53 on the corresponding pin 57. Because of the hook elements 54a formed at the free ends 54a the compression force Pv acts on the spring legs 54, the ends of the spring legs 54 bend inwardly about their bending axis Y along the dot-dashed line Z.
An axially compact shock absorber spring means 28 can be built up from equal parts comprising spring elements 30 in the form of easily punched spring segments 52 in this embodiment. The outer spring segments 52a are connected with the remaining spring segments 52 for transmission of the spring forces by the connecting means 55. The force transmission because of the hole 53 in the end segments 52 is particularly appropriate, since by themselves the ends of the spring legs 54 move inwardly with increasing load and thus friction and eventually wear could occur on engagement of the spring legs 54 on the hollow gear 15 and/or the bearing member 29. The inner throughgoing passage 58 of the spring segments 52 has a small collar 59, which acts to provide a spacing between the individual spring segments 52, so that between the spring segments 52 only a minimal friction occurs. The hook elements 54a of the spring legs 54 can be provided with a crimped portion 60 for reinforcement.
Another embodiment of the connecting means 55, in which the respective free end portions 54b of the spring legs are provided alternately with a catch element 61 and a corresponding catch hole or recess 62, instead of the right angle bend in the spring legs 54 of the previous embodiment, as shown in FIGS. 11 and 12. As shown in FIG. 12 with this connecting means 55 the catch element 61 on one spring leg 54 can engage in the catch hole 62 in the neighboring spring leg to make the connection between the spring legs. Also here the compact leg spring set is mounted under tension by rotation in the direction of the drive torque of the end spring segments between the fixed pins 57 of the bearing member 29 and the pins 56 of the hollow gear 15. Also here the hollow gear bears on the housing-fixed stop means in the configuration under tension.
Since these spring elements are centered by the inner passage 58, shock absorber spring means 28 with this type of spring element 30 is also suitable for use in a rotating arrangement, for example between the drive of the planetary gear unit 14 and the free wheel clutch 20 or between the free wheel clutch 20 and the starting gear 22. Imbalance problems caused by mass distribution changes as a result of wear are largely prevented. Also like the other embodiments of the shock absorber spring means an overload protection is guaranteed by a rotary connection between the hollow gear 15 and the housing-fixed bearing member 29, as shown in FIG. 2.
Another embodiment is shown in FIGS. 13 and 14, in which the shock absorber spring means 28 engages on one end in the transmission gear unit 14 and on the other end on the drive shaft 18, which cooperates with the carrier shaft 19 of the free wheel clutch 20 by the coarse thread 70. In this embodiment too the transmission gear unit is a planetary gear, whose gear support 117 has a central opening 71 for receipt of the drive shaft 18. From FIG. 14 one can see that this central opening 71 has three circumferentially distributed cavities 72, in which a radially outwardly extending rib element 73 of the transmission gear shaft 18 projects. Further spring elements 30 of the shock absorber spring means 28, which are in the form of coil springs, are positioned in these cavities 72, each of which are braced under tension with one end on a rib element 73 and with the corresponding opposite end on a shoulder 75 of the cavity 72.
Still another embodiment of the starter 10 is shown in FIGS. 15 and 16 which show only the portion of the drive train of the starter with the guide ring 26, the starter spring 27, the carrier shaft 19, the free wheel clutch 20 and the starting gear 22. The shock absorber spring means 28 engages at one end on the free wheel clutch 20 and at the other end on the starting gear 22. From FIG. 16 one can see that in this embodiment also coil springs 80 are distributed circumferentially between the hub 21 of the free wheel clutch 20 and the starting gear 22, in which the coil springs 80 are held under tension in a similar manner as in FIG. 14 between a radially outwardly direction rib element 81 on the starting gear 22 and a shoulder 82 of the cavity 83 in the hub 21.
The embodiments of the starter 10 which are shown are designed for a certain rotation direction so that the shock absorber spring means 28 is of course designed for that drive direction.
While the invention has been illustrated and described as embodied in a starter apparatus for an internal combustion engine, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.
What is claimed is new and desired to be protected by Letters Patent is set forth in the appended claims. | The starter apparatus for an internal combustion engine includes a starter motor; an axially shiftable starting gear engageable with a ring gear of the internal combustion engine; a drive train for transferring rotary motion of a drive shaft of the starter motor to the starting gear, the drive train including a plurality of parts from the starting gear to the drive shaft; a free wheel clutch coupled with the drive shaft of the starter motor; and a shock absorber spring device for damping torque shocks between the starting gear and the drive shaft occurring on operation of the starter and located in the drive train between the starting gear and the drive shaft of the starter motor. According to the invention the shock absorber spring device is prestressed to provide a torque acting in a drive rotation direction equal to from 15 to 50% of the stall torque of the starter motor delivered to the starting gear and a ratio of the torsional rigidity of another drive train equal to the above drive train without the shock absorber spring device and at the stall torque to the torsional rigidity of the shock absorber spring device effective at the starting gear must be at least 4. | 5 |
This is a continuation of application Ser. No. 07/991,007, filed Dec. 16, 1992, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a light emitting diode(LED) fabricated with resistors for variable light intensity, and more particularly, to an LED fabricated with resistors for variable light intensity so that, if the LED, as being fabricated into one chip, not as a lamp type, is employed in such device as the brake light of a motor vehicle which requires at least two levels of light intensity, its product life can be increased and the cost of the product can be reduced.
DESCRIPTION OF THE PRIOR ART
Conventionally, the LED has been used as a brake light for high top mount on a car. The overall driving circuitry thereof, however, is complicated in comparison with that of the LED according to the present invention, which is fabricated into one chip together with resistors, because the conventional brake light circuitry requires separate resistors to be connected to the LED so that the LED can emit light with at least two levels of intensity. Accordingly, the LED has rarely been used as a rear lamp for indicating the braking state of a car.
It is essential that most circuits utilizing the LED should employ hybrid resistors in order to control the current through the LED, and also separate resistors in order to protect the LED from damage.
That is, separate resistors are required in order to limit the current as much as necessary which flows to the LED from the power supply for driving the LED. Further, a switch or a switching device should be incorporated in the driving circuit in order to drive the LED with its light intensity varied. Thus, the conventional driving circuit may be highly complicated in structure, causing the manufacturing cost thereof also to be greatly increased.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the problems involved in the prior art. It is an object of the present invention to provide an LED fabricated with resistors for variable light intensity, which is capable of controlling the light intensity of the LED with at least two levels, through one chip fabrication of the LED and the resistors by utilizing the manufacturing process of the LED having the conventional single or double heterostructure and by utilizing an etching process for providing a resistance region.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will now be described in detail with reference to the accompanying drawings, in which:
FIG. 1 is a plan view of the LED having the double heterostructure illustrating one embodiment of the present invention;
FIG. 2 is a cross-sectional view taken along line A--A' in FIG. 1;
FIG. 3 is a cross-sectional view similar to FIG. 2, showing another embodiment of the present invention;
FIG. 4 shows the equivalent circuit of the LED according to the embodiments of the present invention;
FIG. 5 is a cross-sectional view similar to FIG. 2, showing the LED with a single heterostructure of the present invention;
FIG. 6 is a cross-sectional view similar to FIG. 2, but having one of the LED electrode at the opposite side of the substrate; and
FIG. 7 is a cross-sectional view similar to FIG. 3, but with one of the LED electrode removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described, referring to FIGS. 1 to 7.
Referring to FIGS. 1 and 2 showing the LED having double heterostructure according to one embodiment of the present invention, an LED portion a includes a P clad layer 3a, an active layer 4a and an N clad layer 5a which are successively laminated on one side of the upper surface of a P type substrate 2 with predetermined thicknesses respectively. A resistor portion b includes another P clad layer 3b, another active layer 4b and another N clad layer 5b which are successively laminated on the other side of the upper surface of the P type substrate 2, being separated from the LED portion a.
In an LED having single heterostructure (not illustrated), the P clad layers 3a and 3b may be excluded from the above-described structure. The efficiency of single heterostructure is reduced by half in comparison with that of double heterostructure.
On the upper surface of the P type substrate 2, a P type electrode terminal 6 is provided, surrounding the P clad layer 3a, and, on the upper surface of the N clad layer 5a of the LED portion a, an N type electrode terminal 7 is provided. A plurality of resistor terminals 8 to 10 are provided on the upper surface of the N clad layer 5b of the resistor portion b so that the resistor terminals are respectively positioned to define the corresponding resistance values different from one another. The resistor portion b is exclusively used as a resistance region while the LED portion a functions as the LED.
Referring to FIG. 3 showing another embodiment of the invention, the active layers 4a and 4b are completely exposed and the P clad layers 3a and 3b are partially exposed. The P type electrode terminal 6 is provided on the upper surface of the remaining P clad layer which is not etched. Also, as shown in FIG. 3, a selective P type electrode terminal 1 may be provided on the bottom surface of the P type substrate 2 in order to be selectively used. Such selective P type electrode terminal 1 may also be applicable to the embodiment of FIG. 2. However, it is not applicable to the case of a semi-insulating substrate.
The operation and effect of the present invention constructed as mentioned above will now be explained with reference to FIGS. 1 to 4.
The LED according to the present invention may be adapted for use in devices that require two levels of light intensity such as the brake light of a car.
Referring to FIG. 4, the current through the LED may be varied according to ON/OFF states of two switches Sa and Sb and resistance values of resistors Ra and Rb connected thereto, causing the LED to emit variable intensity light.
If a brake pedal(not illustrated) of a car is not activated during day-time driving, both switches Sa and Sb are determined to be turned OFF and the LED maintains its OFF state.
If the brake pedal of the car is activated during day-time driving, the switch Sa is determined to be turned OFF, while the switch Sb is turned ON. Accordingly, the power supply is fed into the LED through the resistor Rb which resistance value is lower than that of the resistor Ra, and a current of intermediate amount(For example, in case that Ra=4KΩ and Rb=600Ω, Ib≈20 mA.) flows to the LED, causing it to emit light at an intermediate level of intensity. Thus, even in the day-time, a driver in a car to the rear can easily observe the braking state of the car in front.
In the meantime, if the pedal is not activated during night-time driving, the switch Sa is determined to be turned ON while the switch Sb is turned OFF. Accordingly, a current of minimum amount(In the above example, Ib≈3 mA.) flows to the LED through the resistor Ra and the LED emits light at a minimum level of intensity. However, a driver to the rear can easily observe the car in front, as there is no disturbance caused by sunlight.
If the pedal is activated during night-time driving, both switches Sa and Sb are determined to be turned ON. Accordingly, the overall current through the resistors Ra and Rb(In the above example, I=Ia+Ib≈23 mA.) flows to the LED, causing it to emit a light at a maximum level of intensity. Thus, a driver to the rear can easily observe the car in front, even though the light is partially attenuated by the headlights of the cars in the rear.
The fabricating method of the LED with resistors for variable light intensity according to the present invention will now be explained in detail.
In the embodiment of FIG. 2, the P clad layer, the active layer and the N clad layer are successively laminated on the upper surface of the P type substrate 2, and then the layers are partially removed by photoetching, so that the P type substrate 2 is exposed and the remaining P clad layers 3a and 3b, active layers 4a and 4b, and N clad layers 5a and 5b define the LED portion a and the resistor portion b, respectively.
In the embodiment of FIG. 3, the photoetching effects partial exposure of the P clad layer, not of the P type substrate 2. Also, the selective P type electrode 1 may be formed on the bottom surface of the substrate 2 by a conventional method.
Thereafter, the P type electrode 6 is formed on the upper surface of the P type substrate 2(in the embodiment of FIG. 2), or on the upper surface of the P clad layer which remains around the P clad layer 3a of the LED portion a (in the embodiment of FIG. 3).
Also, the N type electrode 7 is formed on the upper surface of the N clad layer 5a as the negative terminal of the LED, and is commonly connected to one terminal of the selection switch Sa for selecting day-time/night-time driving and one terminal of the brake switch Sb. The resistor terminals 9 and 8, which are respectively connected to the other terminals of the switches Sa and Sb, are formed on the upper surface of the N clad layer 5b of the resistor portion b, being positioned to define the corresponding resistance values respectively.
In the embodiments as described above, the shape of the resistor portion b may be varied according to the resistance values desired to be obtained. For example, the resistor portion b may be " " shaped as shown in FIG. 1. In this case, the resistor terminals 8 and 9 are formed at both ends on the upper surface of the N clad layer 5b and the resistor terminal 10 is formed in a position where the distances between the resistor terminals 9 and 10 and between the resistor terminals 8 and 10 correspond to the resistance value(4 KΩ) of the resistor Ra and the value (600Ω) of the resistor Rb, respectively. That is, as shown in FIG. 1, the distance of the path between the electrodes 9 and 10 on the N clad layer 5b is less than the distance of the path between the electrodes 8 and 10. Accordingly, the resistance between the electrodes 9 and 10 is less than the resistance between the electrodes 8 and 10.
According to aging test results for LEDs fabricated with resistors for variable light intensity according to the present invention, a 5% deterioration of the light power occurred at a temperature of 35° C., under a current flow of 36 mA(i.e., current density of 45A/cm ), after 1,000 hour. This result corresponds to a brightness of 1,000 mcd and a lifetime of 100,000 hours or more, at normal temperature, under a current flow of 20 mA.
According to the present invention as described above, the resistors for variable light intensity are fabricated with the LED during the manufacturing process thereof, without requiring any additional process, and-thus, if an LED according to the present invention is used as the brake light of a car, its life may be almost semi-permanent; separate hybrid resistors are not required; its driving circuitry can be simplified; and great reductions in manufacturing costs and power consumption can be achieved.
While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes and revisions, such as kinds of LED, manufacturing processes of the LED, types of the substrate, shapes of the resistor portion corresponding to the resistance values desired to be obtained, etc., may be made therein within the scope of the appended claims. | A light emitting diode (LED) and resistors for varying the light intensity of the LED are formed on a single chip. Each of the LED portion and the resistor portion includes an active layer and a clad layer successively deposited on a substrate of the chip. The substrate may be doped with one of P-type dopant and N-type dopant and the clad layer with the other of P and Y-type dopants. A first and second electrodes are formed on an exposed surface of the substrate and the clad layer of the LED portion respectively. A plurality of resistor electrodes are formed on the clad layer of the resistor portion. It is preferable to have different spacing between the resistor electrodes to form variable resistances. | 7 |
RELATED APPLICATION
This application claims priority on U.S. Provisional Application 60/143,141, filed Jul. 7, 1999.
FIELD OF THE INVENTION
The present invention pertains to vacuum valves for applied processing systems and, more particularly, to an improved quick release clamp mechanism for connecting and disconnecting the bonnet and flange of gate valves.
BACKGROUND OF THE INVENTION
My U.S. Pat. No. 5,791,632, entitled “Quick Release Slide Lock for Vacuum Valve,” discloses a quick release clamp mechanism for releasing or disengaging the bonnet of the gate valve actuator from the valve body flange associated therewith. The disclosure of this reference is incorporated herein. While the quick release mechanism disclosed in this patent provides an efficient quick release and a tight seal for operation, the drive of the computer chip manufacturing industry to smaller and smaller processing systems makes servicing and performing routine maintenance of such systems more difficult. The present invention addresses these difficulties with an improved quick release mechanism that better takes advantage of limited, yet available, space.
DISCLOSURE OF INVENTION
Briefly described, the improved vacuum valve of the present invention comprises a clamp actuator that extends through the end plate of a valve housing that defines a valve chamber and includes a main opening. The clamp actuator extends from above the end plate and is connected to a clamp mechanism of the valve for moving the clamp mechanism between its first position and its second position. A valve plate is provided that is movable within the valve chamber from a first, open position away from the main opening to a second, closed position wherein the valve plate closes the main opening to prevent vacuum media flow, and a valve plate actuator moves the valve plate between its open and closed positions. The valve plate actuator and valve plate are secured to the end plate so that removal of the end plate in an upward direction separates the valve plate actuator and valve plate from the actuator end of the valve housing. The valve housing also includes an end plate engaging member. Further, the clamp mechanism is coupled to one of the end plate and end plate engaging member, with the clamp mechanism having a first position allowing separation of the end plate from the end plate engaging member and a second position that securely holds the end plate to the end plate engaging member in a sealed manner.
In this manner, access is provided from the actuator end of the vacuum valve, or at least from the outer side of the valve actuator, which allows for more compact design of the vacuum valve, while at the same time providing easy access for repair and maintenance purposes.
According to an aspect of the invention, the clamp actuator includes a pinion component and the clamp mechanism includes a rack component coupled to the pinion component, whereby rotation of the pinion component causes linear movement of the rack component, causing the clamp mechanism to move between its first and second positions. Preferably, the clamp actuator includes an elongated drive shaft connected to the pinion component, the elongated drive shaft extending away from the end plate beyond an outer end of the valve plate actuator, to provide access from above the end plate for service.
According to another aspect of the invention, the drive shaft includes an outer end that has a drive coupling for manual rotation of the drive shaft and connected pinion component, in order to shift the clamp mechanism.
These and other features, advantages and objects of the invention will become apparent from the following description of the best mode for carrying out the invention, when read in conjunction with the accompanying drawings, and the claims, which are all incorporated herein as part of the disclosure of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, like reference numerals refer to like parts throughout the several views, wherein
FIG. 1A is a longitudinal sectional view of the actuator assembly of the upper region of the valve body, showing the bonnet and flange connection and the improved quick release mechanism for separating the two;
FIG. 1B is a side elevation view of the actuator housing of FIG. 1A, with the valve housing shown in section;
FIG. 1C is a longitudinal section view of the actuator housing
FIG. 2 is cross-section view of the components of FIG. 1A; and
FIG. 3 is a horizontal section view of the clamp plates and quick release clamp mechanism.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that the described embodiments are not intended to limit the invention specifically to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention.
Referring to FIG. 1A, the improved gate valve 10 of the present invention includes a gate valve mechanism (not shown) that is substantially the same as that disclosed in my U.S. Pat. No. 5,884,899, entitled “Half Profile Gate Valve.” Gate valve 10 is provided with a slide lock mechanism 12 that is similar to that disclosed in my U.S. Pat. No. 5,791,632 entitled “Quick Release Slide Lock for Vacuum Valve” in that it includes a pair of slide lock plates 14 (only one shown) one on each side of the gate valve. Slide lock plates 14 are movable in the direction of arrows 16 and function to lock and release an actuator assembly 30 with respect to valve housing 50 .
Slide lock plates 14 each include a set of four longitudinally spaced slots 18 that receive downwardly extending guide screws 20 from the housing of actuator assembly 30 that function as discussed in my '632 patent. Slide lock plates 14 also include a pair of slots 22 that each receive a shoulder screw 24 , and this design is also disclosed in my '632 patent.
FIGS. 1B and 1C show the design of openings 18 in one of the slide lock plates 14 . Each opening 18 is generally oblong circular in shape and includes a wide diameter half 19 and a neck down small diameter half 21 . The wide diameter half 19 is wide enough to pass the head of a guide screw 20 therethrough, while the neck down region is not. In FIG. 1C, the line delineating the wide and small diameter regions is denoted by reference 23 .
Opening 18 also includes a beveled region 25 , which consists of a bevel cut that has a progressively diminishing depth so as to form a ramp or cam surface 27 . During clamping, the head of a guide screw engages cam surface 27 and is pulled thereby as a slide lock plate is slid longitudinally, in order to clamp the bonnet plate down onto the valve body flange. The slope of cam surface 27 , depicted by arrows 29 , is approximately 5 degrees, which creates sufficient difference in depth of bevel region 25 to clamp the bonnet plate onto the valve body flange. When the gate valve is operational, the vacuum pressure within the valve housing augments the clamping force of the slide lock plates, which together create an adequate seal at the bonnet plate.
The design of actuator assembly 30 is similar to that disclosed in my '899 patent. The upper end of gate valve 10 has been modified to include an enclosure formed by a top plate 32 , an end wall 34 , and side walls (not shown). Top plate 32 provides a mount for a release drive shaft pinion 36 , the upper end of which extends above top plate 32 and outwardly beyond actuator 30 and includes a drive coupling in the form of a hex socket 38 for receiving a wrench for manual turning of shaft 36 .
An upright tubular collar support 40 is secured to the bonnet 42 of gate valve 10 and includes an inner bushing sleeve 44 . Drive shaft pinion 36 extends down through aligned openings in bonnet 42 and the upper flange 46 of valve housing 50 and into a machined recess slot 48 of slide lock plate 14 . The design and operation of shaft 36 and recess 48 are discussed with reference to FIGS. 2 and 3.
Referring to FIG. 1B, with slide lock plate 14 moved to the right, as shown by arrow 16 (along with movement of the other slide lock plate), actuator assembly 30 is able to be lifted from the valve housing 50 , and this is also discussed in my '632 patent.
The bottom end of release shaft 36 is splined to interengage with the teeth of a rack 52 mounted to plate 14 within recess 48 . The splines of shaft 36 are freely released from the teeth of rack 52 upon lifting of actuator assembly 30 , as are guide screws 20 from slots 1 B.
FIG. 2 shows both release shafts 36 and slide lock plates 14 with the pinion ends of shafts 36 engaging racks 52 . Rotation of both release shafts by a maintenance technician causes sliding movement of both slide lock plates, freeing their guide screw heads from the slots of the slide lock plates.
FIG. 3 is a top view of the slide lock plates 14 and the release mechanism of shafts 36 and racks 52 . Each release shaft 36 extends down into its respective recess 48 on the inside of a rack 52 , which are secured at the outer sides of recesses 48 . Rotation of release shafts 36 causes linear movement of slide lock plates 14 in the direction of arrows 16 , which either release guide screws 20 from or engages guide screws 20 with their respective slots 18 , to release or lock the actuator assembly.
Provision of a quick release mechanism accessible from above the gate valve has the advantage of allowing easy access to the gate valve for maintenance purposes. Typically, gate valves are sandwiched between modules of applied processing systems and for this reason have to be fully removed for maintenance and repair. The present invention for removal of only the actuator, leaving the valve mechanism and/or housing in place.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto when read and interpreted according to accepted legal principles such as the doctrine of equivalents and reversal of parts. | An improved slide lock mechanism for a vacuum valve ( 10 ) including an end plate or bonnet ( 42 ) mounted to an end flange ( 46 ) and a pair of slide lock plates ( 14 ). An elongated drive shaft pinion ( 36 ) drives a rack ( 52 )connected to slide lock plates ( 14 ), to linearly shift the slide lock plates into clamping engagement with guide screws ( 20 ), thus achieving a tight seal at upper flange ( 46 ) and bonnet ( 42 ). Elongated drive shaft pinion ( 36 ) provides access from above vacuum valve for disengaging, or unclamping, the valve plate and its actuator for repair or maintenance. | 8 |
BACKGROUND OF THE INVENTION
As described in co-pending U.S. application Ser. No. 799,862 filed May 23, 1977 entitled "Heat Stabilizer Composition for Halogenated Resins", certain alkaline earth metal mercaptides are particularly useful as synergists in conjunction with certain sulfur containing organotin or antimony compounds.
In the above cited patent application, the alkaline earth metal mercaptides are perpared in accordance with the following reactions; wherein M is the alkaline earth metal:
M + 2R'OH→M(OR').sub.2 + H.sub.2 (I)
m(or').sub.2 + 2hsr→m(sr).sub.2 + 2r'oh (ii)
the economics of carrying out such reactions commercially is less than ideal, as metals, M, are expensive. Other known methods by which certain metal alkoxides may be conveniently prepared are summarized by D. C. Bradley in "Progress in Inorganic Chemistry", Vol. 2 (edited by F. A. Cotton, Interscience Publishers, Inc., New York, N.Y., 1960, pp. 303ff). However, the only method cited by Bradley for preparing the alkaline earth metal alkoxides involves starting with the metal which is commercially uneconomical.
The oxides and hydroxides (hydrated or anhydrous) of the alkaline earth metals represent a much lower cost source for the metal M than the free metal itself.
The process of this invention provides a process for preparing the desired mercaptide starting with the corresponding metallic oxide or hydroxide; a relatively low-cost alkoxide of magnesium, aluminum or calcium; and an inexpensive alcohol. The other starting material required is a mercaptan of the corresponding desired metal mercaptide.
SUMMARY OF THE INVENTION
The process of this invention provides a simple two-step process for preparing the desired alkaline earth metal mercaptides useful as synergists for organotin stabilizers. The process provides excellent yields at substantial savings over other presently known methods. In the first step there is formed an alkoxide, M(OR 1 ) 2 by one of the following reactions:
MO + M.sup.1 (OR.sup.1).sub.x + R.sup.1 OH→M(OR.sup.1).sub.2 + M.sup.1 (OH).sub.x (III)
m(oh).sub.2 + m.sup.1 (or.sup.1).sub.x R.spsb.1.sub.OH M(OR.sup.1).sub.2 + M.sup.1 (OH).sub.x (IV)
wherein:
M 1 is Mg, Al, or Ca;
M is Ca, Sr, or Ba;
R 1 is a hydrocarbon radical having from 1-20 carbon atoms and is selected from the group consisting of alkyl, cycloalkyl, or aralkyl, optionally substituted with inert noninterfering groups such as halogen and alkoxy; and, x is equal to the valence of M 1 .
In the second step, the desired metal mercaptide is produced according to the reaction:
M(OR.sup.1).sub.2 + 2HSR→M(SR).sub.2 + 2HOR.sup.1 (V)
wherein:
R is a hydrocarbon radical having from 1 to 22 carbon atoms and is selcted from the group consisting of alkyl, cycloalkyl, aryl and mixed alkyl-aryl, said hydrocarbon radicals can optionally have a non-interfering substituent selected from the group consisting of halogen, --XH, --XR 2 , ##STR1## where R 2 is a hydrocarbon radical having from 1-20 carbon atoms and is selected from the group consisting of alkyl, alkenyl, cycloalkyl, aryl and mixed alkyl-aryl with the proviso that R 2 may be further substituted with inert substituents and X and Y are
independently selected from the group consisting of oxygen and sulfur.
The starting alkoxide M 1 (OR 1 ) x may be readily prepared by a number of known methods. See Bradley, "Progress in Inorganic Chemistry", Vol. 2, referred to in the "Background of the Invention", supra.
The process of this invention is defined as a process for preparing alkaline earth metal mercaptides of the general formula M(SR) 2 , wherein M is selected from the group consisting of barium, strontium, and calcium and R is a hydrocarbon radical having from 1 to 22 carbon atoms and is selected from the group consisting of alkyl, cycloalkyl, aryl and mixed alkyl-aryl, said hydrocarbon radicals can optionally have a non-interfering substituent selected from the group consisting of halogen, --XH, --XR 2 , ##STR2## where R 2 is a hydrocarbon radical having from 1-20 carbon atoms and is selected from the group consisting of alkyl, alkenyl, cycloalkyl, aryl and mixed alkyl-aryl with the proviso that R 2 may be further substituted with inert substituents and X and Y are independently selected from the group consisting of oxygen and sulfur, comprising:
(1) forming a reaction mixture of:
(a) a metal alkoxide of the general formula M 1 (OR 1 ) x , wherein M 1 is selected from the group consisting of magnesium, aluminum or calcium with the proviso that when M 1 is calcium M is barium or strontium: R 1 is a hydrocarbon radical having from 1-20 carbon atoms and selected from the group consisting of alkyl, cycloalkyl or aralkyl with the proviso that the hydrocarbon radical can be substituted with inert or noninterfering substituents; and x is a number equal to the valence of M 1 ; and
(b) a metal oxide or hydroxide of the formula MO or M(OH) 2 , wherein M is selected from the group consisting of barium, strontium or calcium; and
(c) an alcohol of the general formula R 1 OH wherein R 1 is as above defined;
(2) subjecting the reaction mixture of (1) to reaction conditions that includes heating the mixture for sufficient time to provide M 1 (OH) x and a metal alkoxide of the general formula M(OR 1 ) 2 ;
(3) forming a reaction mixture of: (a) the metal alkoxide M(OR 1 ) 2 of step (2), and (b) a mercaptan of the general formula RSH, wherein R is as above defined;
(4) subjecting the mixture of (3) to reaction conditions to provide the alkaline earth metal mercaptide of the general formula M(SR) 2 ; and then
(5) separating the metal mercaptide M(SR) 2 from the mixture of step (4).
It is preferable for the alcohol, R 1 OH in reaction III above to be present in a molar excess to serve as a solvent for the reaction. In reaction IV above the alcohol serves solely as a solvent.
It is preferred that R 1 is selected from the above group to provide an alkoxide M(OR 1 ) x that is more soluble than the hydroxide M 1 (OH) x in the mixture of step (2), to facilitate separation of the alkoxide M(OR 1 ) x from the mixture, in the event the alkoxide is isolated from the mixture prior to commencing step (3).
In step (2) above the reaction mixture is preferably heated to the boiling point of the alcohol, R 1 OH for a sufficient time to substantially complete the reaction.
It is preferred that M be barium or calcium whereas magnesium or aluminum are preferable for M 1 . R 1 is preferably an alkyl group of 1 through 8 carbon atoms that can optionally be substituted with inert or non-interfering substituents.
After step (2) above it is preferred to separate the alkoxide M(OR 1 ) 2 from the mixture of step (2) prior to forming the reaction mixture of step (3).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the preferred practice of this invention, the two reactants (according to reaction III or IV above) are added to the reactor in the ratio of x moles of MO or x/2 moles of M(OH) 2 per mole of M 1 (OR 1 ) x . In reaction III sufficient alcohol, R 1 OH, is added to provide at least x moles (and preferably more, the excess acting as a solvent for the reaction as in reaction IV). The reaction mixture is heated to the boiling point of the alcohol for a period of time ranging from about 10 minutes to about 5 hours, typically 30 minutes to about 90 minutes, to ensure that the precipitation of M 1 (OH) x is completed. The driving force for reaction III or IV is the precipitation of the hydroxide of M 1 . The alkoxide M(OR 1 ) 2 , should generally be soluble in the solvent in order to allow separation from M 1 (OH) x . M 1 (OR 1 ) x , MO and M(OH) 2 may or may not be soluble in R 1 OH, the only requirement being that M 1 (OH) x be less soluble so that reaction III or IV can be driven completely to the right (or nearly so). The hydroxide, M 1 (OH) x , is usually separated from the solution of the alkoxide M(OR 1 ) 2 by filtration, either hot or cold. Subsequently, the alkoxide M(OR 1 ) 2 may precipitate partially or entirely from solution. This is not critical and is of no importance to the success of this invention. In either case, it may be used in the reaction with RSH to produce the mercaptides.
In the preferred practice of reaction V, the mercaptan RSH may be added neat, or as a solution in R 1 OH, or as a solution in an inert solvent such as pentane, hexane, heptane, cyclohexane, benzene, toluene, etc. (preferably one whose boiling range is approximately the same as R 1 OH or lower). The temperature of the reaction may range from about 0° to the boiling point of the solvent. The preferred temperature range is about 15° to about 60°C. The molar ratio of mercaptan RSH to metal alkoxide M(OR 1 ) 2 may range from >2:1 to 2:1 with the preferred ratio being 2:1.
At the end of the reaction, the reaction mixture is usually clear and colorless. If it is hazy, or if a slight precipitate is present, it may be clarified by filtration. The filtrate is then stripped under vacuum to afford the desired metal mercaptide.
It is also possible to run reactions III or IV and V sequentially without removing the hydroxide M 1 (OH) x at the end of reaction III or IV. It is then removed at the end of reaction V, prior to removal of solvent. This one-pot procedure, however, does not usually yield as good a quality product.
In order to more clearly demonstrate the process of this invention, the following examples are presented. These are not to be construed as limiting the scope of this invention.
EXAMPLE 1
Into a one-liter, three-necked flask equipped with a mechanical stirrer, water condenser, and an addition funnel, are placed 1.22g (0.05 mole) of magnesium turnings, 100 ml of methanol, and a small crystal or iodine. The reaction mixture is heated cautiously, and in 5-10 minutes a vigorous evolution of hydrogen occurs to provide the alkoxide, Mg(OCH 3 ) 2 . The source of heat is removed and in another 10 minutes all of the magnesium dissolves. The mixture is refluxed for 30 minutes to ensure complete reaction and then allowed to cool to room temperature.
In a separate vessel, under nitrogen, a solution of barium oxide in methanol is prepared by dissolving 15.33g (0.10 mole) of barium oxide in 150 ml of methanol. The dissolution, which is quite exothermic, is allowed to proceed for 10 minutes after which time the solution is filtered in order to remove a small amount of insolubles. The clear filtrate is placed in an addition funnel and is added over a period of 45 minutes to the magnesium methoxide solution formed in the first step.
The mixture is refluxed for 2.5 hours during which time magnesium hydroxide precipitates. After cooling to room temperature, the mixture is filtered.
The clear filtrate is placed in a 1-liter, three-necked flask equipped with a mechanical stirrer, water condenser, and an addition funnel. A solution of 40.87g (0.20 mole) of isooctyl thioglycolate in 100 ml of methanol is placed in the addition funnel and then added over a period of 45 minutes to the reaction solution. The resultant solution is concentrated under reduced pressure to give essentially a quantitative yield of barium bis(isooctyl thioglycolate).
Anal. Calcd. for C 20 H 38 BaO 4 S 2 : S(mercapto), 11.79. Found: S(mercapto), 10.31.
EXAMPLE 2
A solution of magnesium methoxide is prepared as described in Example 1 from 1.22g (0.05 mole) of magnesium turnings and 100 ml of methanol. To this solution is added over a period of 45 minutes a filtered solution of 15.33g (0.10 mole) of barium oxide in 150 ml of methanol, prepared as described in Example 1. The mixture is refluxed for 1.5 hours, cooled to room temperature, and filtered to remove magnesium hydroxide. The clear filtrate is transferred to a 1-liter, three-necked flask equipped with a mechanical stirrer, water condenser, and an addition funnel. A solution of 40.87g (0.20 mole) of isooctyl thioglycolate in 100 ml of methanol is added over a period of 45 minutes. After stirring for 1 hour, the slightly hazy solution is filtered and 54.0g of diethylene glycol dimethyl ether (diglyme) is added as diluent. Methanol is removed under reduced pressure to yield approximately a 1:1 barium bis(isooctyl thioglycolate)/diglyme mixture that weighs 96.4g. This mixture contains 48% barium bis(isooctyl thioglycolate) by titration with a standard iodine solution.
EXAMPLE 3
The procedure of this Example is identical to that described for Example 1 except that 2.02g (0.05 mole) of calcium metal turnings are used in place of magnesium turnings. There is obtained 51.3g of barium bis(isooctyl thioglycolate). Yield is about 94%.
EXAMPLE 4
A solution of magnesium methoxide in methanol is prepared as described in Example 1 from 1.22g (0.05 mole) of magnesium turnings and 150 ml of methanol. To this solution is added solid barium oxide (15.33g, 0.10 mole). The mixture is refluxed for 2.5 hours, cooled to room temperature, and filtered to remove magnesium hydroxide. The clear filtrate is placed in a 1-liter three-necked flask equipped with a mechanical stirrer, addition funnel, and water condenser. A solution of 40.87g (0.20 mole) of isooctyl thioglycolate in 150 ml of methanol is added over 45 minutes. After stirring for 1 hour longer, the slightly hazy solution is filtered and the filtrate concentrated under reduced pressure to provide an essentially quantitative yield of barium bis(isooctyl thioglycolate).
Anal. Calc. for C 20 H 38 BaO 4 S 2 : S(mercapto), 11.79. Found: S(mercapto), 10.23.
EXAMPLE 5
A solution of magnesium methoxide in methanol is prepared as described in Example 1 from 1.22g (0.05 mole) of magnesium turnings and 150 ml of methanol. Barium oxide (15.33g, 0.10 mole) is added followed by refluxing for 2.5 hours. After the mixture is cooled to room temperature, it is filtered to remove magnesium hydroxide. The filtrate is transferred to a 1-liter three-necked flask equipped with a mechanical stirrer, addition funnel, and a water condenser, and a solution of 38.46g (0.20 mole) of dodecyl mercaptan in a methanol-hexane mixture (100 ml: 30 ml) is added over a period of 45 minutes. After stirring for one hour, the solution is concentrated under reduced pressure to yield 49.4g (95% yield) of barium bis(dodecyl mercaptide)
Anal. Calcd. for C 24 H 59 BaS 2 : S(mercapto), 12.33. Found: S(mercapto) 10.58.
EXAMPLE 6
Following the procedure in Example 4 except that aluminum (with a trace of HgCl 2 as catalyst) is used in place of magnesium, calcium in place of barium, and ethanol in place of methanol, there is obtained calcium bis(isooctyl thioglycolate).
EXAMPLE 7
Following the procedure outlined in Example 6 except that strontium is used in place of calcium, and methanol in place of ethanol, there is obtained strontium bis(isooctyl thioglycolate).
EXAMPLE 8
Following the procedure outlined in Example 4 except that dibutyl mercaptosuccinate is used in place of isooctyl thioglycolate, there is obtained barium bis(dibutyl mercaptosuccinate).
EXAMPLE 9
Following the procedure outlined in Example 7 except that dipropyl mercaptosuccinate is used in place of isooctyl thioglycolate, there is obtained strontium bis(dipropyl mercaptosuccinate).
EXAMPLE 10
Following the procedure outlined in Example 6 except that isooctyl 3-mercaptopropionate is used in place of isooctyl thioglycolate, there is obtained calcium bis(isooctyl 3-mercaptopropionate).
EXAMPLE 11
Following the procedure outlined in Example 4 except that aluminum (with a trace of HgCl 2 as catalyst) is used in place of magnesium, and isooctyl 3-mercaptopropionate in place of isooctyl thioglycolate, there is obtained barium bis(isooctyl 3-mercaptopropionate).
EXAMPLE 12
The procedure of Example 1 is repeated except that the below enumerated R groups in (RSH) are substituted for the one of Example 1:
methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl, hexyl, octyl, decyl, dodecyl, tridecyl, hexadecyl, octadecyl, cyclopentyl, cyclohexyl, cyclooctyl, benzyl, β-phenylethyl, β-phenylpropyl, γ-phenylpropyl, 2-hydroxyethyl, 2-ethoxyethyl, carboethoxymethyl, carbooctoxymethyl, 1-carbooctoxyethyl, 2-carbooctoxyethyl, 2-dimethylaminoethyl, 2-stearoxyethyl, 2-acetoxyethyl, 2,3-diacetoxypropyl, 2,3-dilauroxypropyl, 2-hydroxy-3-octoxypropyl, 4-methylcyclohexyl, 4-methoxycyclohexyl, 2-methoxycyclopentyl, p-phenylbenzyl, o-methoxybenzyl, phenyl, tolyl, naphthyl, 1,2-dicarbobutoxyethyl, 1,1-dicarbobutoxymethyl, 1-carbobutoxy-2-carbooctoxyethyl, 1-carbomethoxyl-carbooctoxymethyl, 2-methylmercaptoethyl, 2-thiocarbooctoxyethyl, and thiocarbothiobutoxymethyl.
In each case the corresponding barium mercaptide is obtained.
EXAMPLE 13
The procedure of Example 1 is repeated except that the following R 1 groups are substituted for the methyl of Example 1: ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl, hexyl, octyl, lauryl, oleyl, dodecyl, cyclopentyl, cyclohexyl, cycloheptyl, benzyl, β-phenylethyl, β-phenylpropyl, γ-phenylpropyl, 2-methoxyethyl, 2-chloroethyl, 2-phenoxyethyl, 2-methoxypropyl, 2-butoxypropyl, 2-dimethylaminoethyl, 3-diethylaminopropyl, 2(2'-ethoxyethoxy)ethyl, p-phenylbenzyl, p-methylbenzyl, o-ethylbenzyl.
In each case the desired mercaptide, barium bis(isooctyl thioglycolate), is obtained.
EXAMPLE 14
A solution of magnesium methoxide in methanol is prepared as described in Example 1 from 1.22g (0.05 mole) of magnesium turnings and 150 ml of methanol. To this solution is added solid barium hydroxide (8.57g, 0.05 mole). The mixture is refluxed for 2.5 hours, cooled to room temperature and filtered to remove magnesium hydroxide. The clear filtrate is placed in a 1-liter three-necked flask equipped with a mechanical stirrer, addition funnel, and water condenser. A solution of 20.43g (0.10 mole) of isooctyl thioglycolate in 150 ml of methanol is added over 45 minutes. After stirring for 1 hour longer, the slightly hazy solution is filtered and the filtrate concentrated under reduced pressure to provide an essentially quantitative yield of barium bis(isooctyl thioglycolate).
EXAMPLE 15
Following the procedure outlined in Example 14 except that calcium hydroxide (3.71g, 0.05 mole) is used in place of barium hydroxide, there is obtained calcium bis(isooctyl thioglycolate) in essentially quantitative yield. | A process for preparing alkaline earth metal mercaptides in a two-step process, useful as synergists for organotin stabilizers in halogen containing resins such as polyvinyl chloride, comprising: (1) reacting a metallic oxide or hydroxide of the metal desired in the final mercaptide; a magnesium, aluminum or calcium alkoxide; and an alcohol to provide an alkoxide of the metal of the final mercaptide; and then (2) reacting the final alkoxide of (1) with a mercaptan to provide the desired metal mercaptide. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a convolutional interleaver or deinterleaver for rearranging bytes forming words of an input word sequence to produce an output word sequence, and in particular to a convolutional interleaver or deinterleaver employing both a direct memory accessed external memory and an internal cache memory for temporarily storing bytes of the input word sequence until they are incorporated into the output word sequence.
2. Description of Related Art
FIG. 1 depicts a typical prior art communication system including a transmitter 10 for converting an input data sequence TX into an outgoing analog signal V 1 transmitted through a communication channel 14 to a receiver 12 . Receiver 12 converts signal V 2 back into an output data sequence RX matching the transmitters' incoming data sequence TX. Since channel 14 can introduce random noise into signal V 2 , it is possible that some of the bits of the RX sequence will not match corresponding bits of the TX sequence. To reduce the likelihood that noise in channel 14 will produce errors in the RX sequence, transmitter 10 includes a forward error correction (FEC) encoder 16 , such as for example a Reed-Solomon encoder, for encoding the incoming data sequence TX into a sequence A of N-byte words. Each word of sequence A “over-represents” a corresponding portion of the TX sequence because it contains redundant data. A convolutional interleaver 18 interleaves bytes of successive words of word sequence A to produce an output word sequence B supplied to a modulator 20 . Modulator 20 generates signal V 1 to represent successive bytes of word sequence B. A demodulator 22 within receiver 12 demodulates signal V 2 to produce a word sequence B′. Word sequence B′ will nominally match the word sequence B input to the transmitter's modulator 20 , though some of the bytes forming word sequence B′ may include bit errors caused by noise in channel 14 . A deinterleaver circuit 24 deinterleaves word sequence B′ to produce a word sequence A′ nominally matching word sequence A, although it too may include errors resulting from the errors in word sequence B′. An FEC decoder 26 then decodes word sequence A′ to produce the output data sequence RX.
Although the A′ sequence may contain some errors, it is possible for FEC decoder 26 to produce an outgoing sequence RX matching the TX sequence because words of the A′ sequence contain redundant data. When a portion of an A′ sequence word representing any particular portion of the RX data is corrupted due to an error in the B′ sequence, another redundant portion of the A′ sequence word also representing that particular portion of the RX sequence may not be corrupted. FEC decoder 26 is able to determine which portions of each A′ sequence word are not corrupted and uses the uncorrupted portions of those words as a basis for determining bit values of its corresponding portion the RX sequence. Each possible FEC scheme will have a limited capability for correcting byte errors. For example, a (255, 16) Reed-Solomon code, including 16 bytes of redundant data to form a 255 bytes code word can correct up to 8 byte errors, but no more.
It is possible for some portion of the RX sequence to contain an error when there are excessive errors within an A′ sequence word representing that particular portion of the RX sequence, but interleaver 18 and deinterleaver 24 help to reduce the chances of that happening. Since noise in channel 14 can occur in bursts that may persist long enough to corrupt portions of signal V 1 conveying every byte of a B′ sequence word, interleaver 18 improves the system's noise immunity by interleaving bytes of successive words of sequence A to produce word sequence B. Since each word of sequence A produced by FEC encoder 16 contains redundant data describing a particular section of the TX sequence, interleaving the words of sequence A to produce words of sequence B has the effect of spreading out information conveyed by signal V 1 so that a single noise burst in channel 14 is less likely to corrupt an excessive number of bytes of information representing the same portion of the TX sequence.
FIG. 2 shows an example of how interleaver 18 might rearrange bytes of sequence A to produce sequence B. In this example each i th word A i of sequence A includes five bytes A i,0 through A i,4 and each i th word of sequence B has five bytes B i,0 through B i,4 . This particular interleaving scheme has an “interleaving depth” D=4 because as shown in FIG. 2 the five bytes of each word A i of sequence A appear as every fourth byte of sequence B. Since the longest noise burst the system can tolerate is a function of how widely interleaver 18 separates the data in sequence B, the noise tolerance of the system increases with interleaving depth D.
When interleaver 18 has an interleaving depth D it must delay each j th byte A i,j of each i th word A i of sequence A by (D−1)×j bytes to form a byte of sequence B. Since interleaver 18 must store a byte in order to delay it, the number of bytes of sequence A interleaver 18 must concurrently store increases with interleaving depth D. When interleaver 18 stores each word of sequence A until it no longer needs any byte of that word to produce a word of sequence B, then the total number of bytes interleaver 18 must concurrently store is N×D where N is the number of bytes per word. Deinterleaver 24 will require a similar internal storage capacity to deinterleave the B′ sequence. Thus, the noise immunity interleaver 18 and deinterleaver 24 can provide is a function of its storage capacity.
FIG. 3 illustrates a prior art interleaver 18 including a controller 28 , an input buffer 30 , a static random access memory (SRAM) 32 and an output buffer 34 all of which may be implemented on the same integrated circuit (IC) 35 . FEC encoder 16 ( FIG. 1 ) writes successive bytes of each successive word of sequence A into input buffer 30 , and whenever it has written an entire word of sequence A into buffer 30 it pulses an INPUT_READY input signal to controller 28 . Controller 28 responds to the INPUT_READY signal by writing each byte of the sequence A word in buffer 30 to a separate address of SRAM 32 . Controller 28 then sequentially reads each byte that is to form a next word of sequence B out of SRAM 32 , stores it in output buffer 34 and then sends an OUTPUT_READY signal to modulator 20 ( FIG. 1 ) telling it that it may read a next word of sequence B out of output buffer 34 .
The algorithm controller 28 employs for producing read and write addresses for SDRAM 32 ensures that each incoming word of sequence A into SRAM 32 overwrites a previous word of sequence A that is no longer needed and ensures that bytes forming words of sequence B are read in the proper order. To interleave N-byte words of incoming sequence A with an interleaving depth D, SRAM 32 must have D×N addressable byte storage locations. The interleaver architecture illustrated in FIG. 3 is typically employed when interleaver 18 can be implemented on a single IC 35 , but when N×D is large it becomes impractical to embed a sufficiently large SDRAM 32 in a single IC.
FIG. 4 illustrates another prior art architecture for an interleaver 18 ′ including a controller 28 ′, an input buffer 30 ′ and an output buffer 34 ′ included within a single IC 35 ′. Interleaver 18 ′ employs an external synchronous dynamic random access memory (SDRAM) 36 for storing bytes rather than an internal SRAM. While controller 28 of FIG. 3 can directly read and write accesses each byte of SRAM 32 , controller 28 ′ of FIG. 4 can only access data in SDRAM 36 via a direct memory access (DMA) controller 38 . Rather than individually read and write accessing each byte stored in SDRAM 36 , DMA controller 38 operates in a “burst” mode wherein it read or write accesses bytes stored at several (typically 16) successive addresses. Thus when controller 28 ′ wants to obtain particular bytes stored in SDRAM 36 to write into output buffer 34 ′, it must ask DMA controller 38 to read a block of bytes including the particular bytes needed to form the next output sequence word. Controller 28 ′ then transfers those particular bytes to output buffer 34 ′. However since bytes are not addressed in SDRAM in the order in which they are needed to from bytes of the outgoing word sequence, many of the bytes DMA controller 38 reads from SDRAM 36 during each DMA read access will be discarded.
Deinterleaver 24 of FIG. 1 may have the same topology as interleaver 18 of FIG. 3 or of FIG. 4 , with the controller 28 or 28 ′ of the deinterleaver implementing an algorithm that deinterleaves the B′ sequence to produce the A′ sequence.
Since SDRAMs are relatively inexpensive, it can be more cost effective for an interleaver or deinterleaver to employ the architecture of FIG. 4 than that of FIG. 3 , particularly when a large amount of memory is needed. However since read and write access to an internal SRAM is typically faster than that of an external SDRAM, interleaver 18 of FIG. 3 can have a higher throughput (in bytes per second) than interleaver 18 ′ of FIG. 4 . The maximum throughput of the interleaver of FIG. 4 can be further limited because much of the bandwidth of SDRAM 36 is wasted reading bytes that are discarded.
What is needed is an interleaver or deinterleaver employing a DMA controller to access an inexpensive external memory, but which improves its data throughput by making more efficient use of its DMA data transfer bandwidth.
BRIEF SUMMARY OF THE INVENTION
A convolutional interleaver or deinterleaver interleaves or deinterleaves a sequence of N-byte incoming words to form a sequence of N-byte outgoing words, with a variable interleaving depth D. An interleaver or deinterleaver in accordance with the invention employs both an external memory and a cache memory for storing bytes of the incoming word sequence until they can be formed into words of the outgoing word sequence. The external (“main”) memory, read and write accessed via a DMA controller, is suitably large enough to hold (Nmax×Dmax bytes) where Nmax is the largest allowable byte width N of each word and Dmax is the largest allowable interleaving depth D. The DMA controller operates in a burst read or write mode in which it read or write accesses a block consecutive addresses of the main memory whenever it read or write accesses the main memory. The cache memory is smaller than the main memory preferably having (BurstLen×Dmax) storage locations, where BurstLen is the number of bytes read from or written to sequential addresses of the main memory during each DMA read or write access. The interleaver or deinterleaver can independently read or write access each individual cache memory address.
When (N×D) is less than (BurstLen×Dmax), the cache memory is sufficiently large to accommodate all of the byte storage requirements of the interleaver or deinterleaver, and only the cache memory is used for storing bytes of the incoming word sequence. The interleaver or deinterleaver writes each byte of each incoming word sequence directly into the cache memory, overwriting a previous word of the incoming word sequence that is no longer needed. On the other hand, interleaver or deinterleaver obtains a next outgoing sequence word from bytes it reads out of the cache memory.
When (N×D) exceeds the size (BurstLen×Dmax) of its cache memory, the interleaver uses the main memory to store incoming sequence words as they arrive and uses its cache memory to store bytes forming a next set of output sequence words it is to generate. When a word of the incoming sequence arrives in an input buffer, the interleaver commands the DMA controller to write bytes of the incoming sequence word to the main memory. The interleaver also writes to the cache memory any bytes of the incoming word that are to be included in the set of outgoing sequence words currently stored in the cache memory. Thereafter the interleaver generates a next word of the outgoing sequence by reading the bytes that form it out of the cache memory and writing them into an output buffer. After transferring each word of the set of outgoing sequence words stored in the cache memory to the output buffer, the interleaver commands the DMA controller to read all bytes out of the main memory that are to be included in a next set of outgoing sequence words and stores those bytes at appropriate locations in the cache memory until they are transferred to the output buffer. The cache memory improves interleaver throughput by maximizing the number of bytes that the DMA controller reads from the main memory during each burst mode DMA read access that can be incorporated into outgoing sequence words.
When (N×D) is larger than the address space of its cache memory, the deinterleaver uses its cache memory to store bytes forming only as many of most recently received set of incoming sequence words as it can hold and uses its main memory to store bytes forming outgoing sequence words. When an incoming sequence word arrives in its input buffer, the deinterleaver forms a next word of the outgoing sequence by transferring any bytes of that outgoing sequence word currently residing the main memory into the output buffer, and by transferring all other bytes of that outgoing sequence word from the cache memory to the output buffer. The interleaver then writes all of the bytes of the incoming sequence word into the cache memory.
Whenever the deinterleaver has filled the cache memory with incoming sequence words, it flushes the cache memory by reading bytes out of the cache memory and using the DMA controller to write those bytes into the main memory. In doing so, the bytes are arranged within the main memory addressed in an order in which the DMA controller can sequentially access them when needed to form output sequence words. This increases the percentage of bytes the DMA controller subsequently reads out of the main memory when forming an output sequence word, thereby improving DMA transfer efficiency and increasing the maximum throughput of the deinterleaver.
The claims appended to this specification particularly point out and distinctly claim the subject matter of the invention. However those skilled in the art will best understand both the organization and method of operation of what the applicant(s) consider to be the best mode(s) of practicing the invention, together with further advantages and objects of the invention, by reading the remaining portions of the specification in view of the accompanying drawing(s) wherein like reference characters refer to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a prior art data communication system in block diagram form.
FIG. 2 depicts how the interleaver of FIG. 1 convolutionally interleaves words of an incoming sequence to produce words of an outgoing sequence.
FIGS. 3 and 4 depict prior art convolution interleavers in block diagram form.
FIG. 5 depicts an example convolutional interleaver in accordance with the invention in block diagram form.
FIG. 6 is a flow chart representing an algorithm executed by the controller of FIG. 5 .
FIG. 7 depicts an example convolutional deinterleaver in accordance with the invention in block diagram form.
FIG. 8 is a flow chart representing an algorithm executed by the controller of FIG. 7 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the use of a cache memory in a convolutional interleaver or a convolutional deinterleaver.
The specification describes exemplary embodiments of the invention considered to be best modes of practicing the invention.
Interleaver
FIG. 5 depicts an example of a convolutional interleaver 39 in accordance with the invention including a controller 40 , an input buffer 42 , a direct memory access (DMA) controller 44 , a multiplexer 48 , a cache memory 50 and an output buffer 52 all of which are preferably implemented on a single integrated circuit (IC) chip 53 . DMA controller 44 read and write accesses a “main” memory 46 , suitably an SDRAM external to IC chip 53 . Interleaver 39 convolutionally interleaves a sequence A of N-byte incoming words with an interleaving depth D ranging up to Dmax to form a sequence B of N-byte outgoing words. The number N of bytes in each incoming word and in each outgoing word may range up to a maximum number Nmax, such as for example 255. Controller 40 is suitably implemented as a programmable state machine so that the values of N and D can be selected by the manner in which controller 40 is programmed.
Main memory 46 suitably has a least Nmax×Dmax storage locations, with each addressable storage location sized to hold a single byte. DMA controller 44 operates in a burst read and write mode wherein it read or write accesses many successive addresses of main memory 46 whenever it read or write accesses main memory 46 . Cache memory 50 preferably includes at least BurstLen×Dmax storage locations where BurstLen is the number (e.g. 16) of successive addresses DMA controller accesses during each burst mode read or write access (its “burst length”). Cache memory 50 can also store one byte at each of its addressable storage locations, but controller 40 can separately and independently read and write access each of its addressable storage locations.
FIG. 6 is a flow chart illustrating an example of controller 40 operation. Referring to FIGS. 5 and 6 , controller 40 waits (step 60 ) until it detects an INPUT_READY signal pulse indicating that an external circuit has written a next word of incoming sequence A into input buffer 42 . When the product of word length N and interleaving depth D (N×D) does not exceed the number of bytes cache memory 50 can store (step 62 ), controller 40 responds to the INPUT_READY signal pulse by signaling DMA controller 44 and multiplexer 48 to transfer all bytes of the incoming sequence word currently residing input buffer 42 into cache memory 50 (step 64 ). Controller 40 then reads all bytes that are to form a next word of outgoing sequence B out of cache memory 50 and transfers them to output buffer 52 (step 66 ). Controller 40 thereafter pulses the OUTPUT_READY signal (step 68 ) and returns to step 60 to await arrival of another word of incoming sequence A in input buffer 42 .
Whenever it writes bytes of an incoming sequence word into cache memory 50 at step 64 , controller 40 overwrites the bytes forming the output sequence word last read out of cache memory 50 at step 66 since it is no longer necessary to store the overwritten bytes in cache memory 50 . Note that when N×D is smaller than the number of available storage locations in cache memory 50 , interleaver 39 does not use main memory 46 for byte storage.
When (N×D) is larger than the number of storage locations in cache memory 50 , controller 40 uses main memory 46 to hold bytes of all incoming sequence words until they are needed and uses cache memory 50 for storing bytes that are to form as many outgoing sequence words as the cache memory can hold. When controller 40 detects an INPUT_READY signal pulse (step 60 ), and when (N×D) is larger than the capacity of cache memory 50 (step 62 ), controller 40 responds to the INPUT_READY pulse by commanding DMA controller 44 to write bytes of the incoming sequence word stored in input buffer 42 into main memory 46 (step 70 ), overwriting bytes stored therein that are no longer needed. Controller 40 also (at step 70 ) transfers to cache memory 50 any bytes currently residing in input buffer 42 that are to be included in any of the outgoing sequence words currently stored in cache memory 50 .
Thereafter controller 40 transfers a first byte of a next word of output sequence B from cache memory 50 to output buffer 52 (step 74 ). If it is not necessary at that point to refill cache memory 50 (step 76 ) and if the controller has not transferred the last byte of the next word of output sequence B to output buffer 52 (step 78 ), then controller 40 returns to step 74 to transfer a next byte of the next output sequence word from cache memory 50 to output buffer 52 . Controller 40 continues to loop through steps 74 - 78 until it written all bytes of the next output sequence word into output buffer 52 . Controller 40 then pulses the OUTPUT_READY signal (step 80 ) to signal an external circuit that the next output sequence word is available in output buffer 52 and returns to step 60 to await a next input sequence word.
Whenever at step 76 controller 40 determines that it has transferred every byte currently in cache memory 50 to output buffer 52 , controller 40 refills cache memory 50 by transferring bytes that are to form a next set of output sequence words from main memory 46 to cache memory 50 (step 82 ). To do so controller 40 commands DMA controller 44 to read appropriate sequences of bytes from main memory 46 , and then transfers bytes DMA controller 44 reads to appropriate addresses of cache 50 . Not every byte needed to form the next set of outgoing sequence words will be written into cache memory 50 at step 82 because some of those bytes will not yet have arrived in incoming sequence words. However as the incoming sequence words containing the missing bytes arrive in input buffer 42 , controller 40 will transfer those missing bytes from input buffer 42 to the appropriate addresses of cache memory 50 at step 70 , thereby completing each output sequence word currently stored in cache memory 50 before that output sequence word is transferred to the output buffer 52 at steps 74 - 78 .
Thus as described above, interleaver 39 uses main memory 46 for storing bytes only when the N×D exceeds the number of available storage locations in cache memory 50 and uses only cache memory 50 for storing bytes of incoming words until they are needed to form outgoing words. Otherwise, interleaver 39 uses main memory 46 for storing all input sequence words and uses cache memory 50 for storing bytes of only as many output sequence words as it can hold.
Cache memory 50 improves the efficiency of DMA read accesses of interleaver 39 compared to the prior art interleaver of FIG. 4 because it reduces the number of bytes its DMA controller reads that have to be discarded. The DMA controller of the prior art interleaver of FIG. 4 reads bytes that are to be included in several outgoing sequence words during each DMA read access, but only those bytes to be incorporated into the next outgoing sequence word are actually used; the rest of the bytes the DMA controller reads are discarded and must be read again at other times when they are actually needed to form a next output sequence word. Since the cache memory 50 of interleaver 39 of FIG. 5 can hold bytes that are to form many outgoing sequence words, fewer of the bytes DMA controller 44 need be discarded. Cache memory 50 therefore reduces the frequency with which DMA controller 44 must read access main memory 46 , thereby increasing the interleaver's available throughput.
Interleaver Algorithm
The following is a list of variables employed in a pseudocode representation of the algorithm depicted in FIG. 6 :
Dmax: Maximum interleaver depth (e.g., 64 for ADSL applications) BurstLen: Burst length of DMA {16, 32, 64, . . . } D: Interleaving depth N: Word length i: Word index (0 to D−1) j: Byte index within the word (0 to N−1) UseIntBuf: Use cache memory only flag DmaRdLen: DMA read length=BurstLen×Dmax/D DmaRdAddr: Starting main memory DMA read address DmaWrLen: DMA write length, equal to N DmaWrAddr: Starting main memory DMA write address DmaRdRqCnt: DMA read request count during the cache refill (0 to D−1) DmaRdPtr: Pointer for DMA read (0 to DmaRdLen−1) CacheFillCnt: Cache refill count (0 to ceil((N×D)/(BurstLen×Dmax))−1) InRdPtr: Input buffer read pointer CacheWrPtr: Cache write pointer CacheRdPtr: Cache read pointer OutWrPtr: Output buffer write pointer
The following is the pseudocode representation of the algorithm of FIG. 6 .
1 ′Initialize
Set i=0, CacheFillCnt=0
If (N×D) < (BurstLen × Dmax),
set UseIntBuf = 1
set CacheRdPtr = 0
Else
set UseIntBuf=0
set CacheRdPtr= BurstLen × Dmax
End if
2 ′Wait for input word
Wait for INPUT_READY
If (UseIntBuf == 1) go to step 3 else go to step 4
3 ′Transfer bytes from Input buffer to cache
Read bytes in input buffer and write to cache with
InRdPtr = mod(N-floor(i × N/D) + j,N) and
CacheWrPtr = mod(i × N,D)+j × D, for j = 0 to N−1
Set OutWrPtr = 0
Go to step 5
4 ′Transfer bytes from input buffer to main and cache
start DMA write at DmaWrAddr = mod(i × N,D) × 256,
for j = 0 to N−1
obtain j th byte of N-byte DMA write from
InRdPtr = mod(N-floor(i × N/D)+j,N),
after InRdPtr reaches 0 and until mod(j,DmaRdLen)=0
also write the j th byte to
CacheWrPtr=mod(i × N,D)+mod(j,DmaRdLen) × D
End For
Set OutWrPtr=0
5 ′Transfer bytes from cache to output buffer
While (OutWrPtr < N and CacheRdPtr < BurstLen × Dmax)
move byte at CahceRdPtr to OutWrPtr
set OutWrPtr = OutWrPtr+1
set CacheRdPtr = CacheRdPtr+1
end while
If (OutWrPtr == N) go to step 7 Else go to step 6
6 ′Transfer bytes from main to Cache
Set DmaRdRqCnt=0
While (DmaRdRqCnt<D)
DMA read min(DmaRdLen,N-CacheFillCnt × DmaRdLen)
bytes
starting at DmaRdAddr=CacheFillCnt ×
DmaRdLen+DmaRdRqCnt ×256
write each byte read to CacheWrPtr =
DmaRdPtr × D+DmaRdRqCnt
Set DmaRdRqCnt = DmaRdRqCnt+1
End While
Set CacheRdPtr = 0
Go to step 5
7 ′Output ready Set i = i+1 Pulse OUTPUT_READY If (i == D) go to step 1 Else go to step 2
Deinterleaver
FIG. 7 depicts an example of a deinterleaver 89 in accordance with the invention including a controller 90 , an input buffer 92 , a direct memory access (DMA) controller 94 , a multiplexer 98 , a cache memory 100 and an output buffer 102 all of which are preferably implemented on a single integrated circuit (IC) chip 103 . Deinterleaver 89 also includes a main memory 96 , suitably an SDRAM, external to IC chip 103 that DMA controller 94 read and write accesses. Deinterleaver 89 convolutionally deinterleaves a sequence B of N-byte incoming words that has been interleaved with an interleaving depth D ranging up to Dmax to form a sequence A of N-byte outgoing words. The number N of bytes in each incoming word and in each outgoing word may range up to a maximum number Nmax, such as for example 255. Controller 90 is suitably implemented as a programmable state machine so that the values of N and D can be selected by the manner in which controller 90 is programmed.
Main memory 96 suitably has at least Nmax X Dmax addressable storage locations, each sized to hold a single byte. DMA controller 94 operates in a burst read and write mode in which it read or write accesses many successive addresses of main memory 96 whenever it read or write accesses main memory 96 . Cache memory 100 preferably has at least (BurstLen×Dmax) addressable byte storage locations, where BurstLen is the burst length of DMA controller 94 . Controller 90 can separately and independently read and write access each byte stored in cache memory 100 .
FIG. 8 is a flow chart illustrating an example of controller 90 operation. Referring to FIGS. 7 and 8 , controller 90 waits (step 110 ) until it detects an INPUT_READY signal pulse from an external circuit indicating a next word of incoming sequence B resides in input buffer 92 . When the product of the word length N and interleaving depth D (N×D) does not exceed the number of bytes cache memory 100 can store (step 112 ), controller 90 responds to the INPUT_READY signal pulse by reading all bytes that are to form a next word of outgoing sequence B out of cache memory 100 and transferring them to output buffer 102 via multiplexer 98 (step 114 ). Controller 90 then writes all bytes of the incoming sequence word currently residing in input buffer 92 into cache memory 100 (step 116 ). Controller 90 then pulses the OUTPUT_READY signal (step 118 ) and returns to step 110 to await arrival of another word of incoming sequence B.
Whenever it writes bytes of an incoming sequence word into cache memory 100 at step 116 , controller 90 overwrites the bytes forming the output sequence word last read out of cache memory 100 at step 114 because it is no longer necessary to store the overwritten bytes in cache memory 100 . Note that when N×D is smaller than the number of available storage locations in cache memory 100 , deinterleaver 89 does not use main memory 96 for byte storage.
When (N×D) is larger than the byte capacity of cache memory 100 , the outgoing word is mainly stored in main memory 96 and controller 90 uses cache memory 100 to store only as many recently incoming sequence words as it can hold. Thus when controller 90 detects an INPUT_READY signal pulse (step 110 ) and when (N×D) is larger than the capacity of cache memory 100 (step 112 ), controller 90 responds to the INPUT_READY pulse by commanding DMA controller 94 to read bytes stored in main memory 96 that are to form the next word of outgoing sequence A. As DMA reads those bytes, controller 90 writes them into appropriate locations of output buffer 102 (step 120 ). Since not all of the bytes of the outgoing word being assembled in output buffer 102 reside in main memory 96 , controller 90 obtains the missing bytes from recently arrived incoming words stored in cache memory 100 and writes them to the appropriate storage locations of output buffer 102 at step 120 . After finishing transferring data bytes of the next word of outgoing sequence A from either main memory 96 or cache memory 100 into the output buffer 102 , the controller 90 writes the bytes of the incoming sequence word stored in input buffer 92 into the cache memory 100 (step 122 ). When storing the incoming sequence word, the controller 90 determines whether cache memory 100 has become full (step 124 ). If so, controller 90 flushes the cache 100 by commanding DMA controller 94 to transfer data bytes stored in cache memory 100 into main memory 96 (step 130 ) by overwriting bytes that are no longer needed. After flushing cache memory 100 , controller 90 stores the remaining bytes of the incoming sequence word into cache memory 100 . After storing the incoming sequence word in the cache memory 100 , controller 90 pulses the OUTPUT_READY signal (step 132 ) to signal an external circuit that the next word of output sequence A is available in output buffer 102 .
Thus as described above, deinterleaver 89 uses main memory 96 for storing bytes only when the N×D exceeds the number of available storage locations in cache memory 100 and uses cache memory 100 for storing all bytes of the most recent D incoming words and the next D output words. Otherwise deinterleaver 39 uses cache memory 96 for storing only as many words of incoming sequence as it can hold, and when cache memory 100 is filled, controller 90 commands DMA controller 94 to transfer the contents of cache memory 100 to main memory 96 . As it writes incoming word bytes into cache memory 100 at step 122 , controller 90 rearranges the order of the bytes so that DMA controller 94 writes them into successive addresses of main memory 96 in an order in which they will be needed later at step 120 when they are transferred to the output buffer. This renders the DMA read operation carried out at step 120 more efficient because it increases the percentage of bytes read out of main memory 96 that can be incorporated into the output sequence word being assembled in output buffer 102 . Cache memory 100 therefore helps to minimize the number of times DMA controller 94 must read access main memory 96 , thereby increasing the deinterleaver's maximum throughput.
Deinterleaver Algorithm
The following is a list of variables employed in a pseudocode representation of an example algorithm implemented by controller 90 of deinterleaver 89 :
Dmax
Maximum interleaver depth (64, for ADSL applications)
BurstLen
Burst length of DMA (16, 32, or 64, and so on)
D
Interleaver depth
N
FEC codeword length
I
Codeword index, i = 0, 1, 2, . . . , D − 1
J
Byte index within the codeword, j = 0, 1, 2, . . . , N − 1
UseIntBuf
Indicates using the internal cache as the interleaving
buffer
DmaRdLen
DMA read length, equal to N
DmaRdAddr
Starting address of the system memory for DMA read
request
DmaWrLen
DMA write length, equal to (BurstLen Dmax/D)
DmrWrAddr
Starting address of the system memory for DMA write
request
DmaWrRqCnt
DMA write request count during the cache flush,
DmaWrRqCnt = 0, 1, 2, . . . , D − 1
DmaWrPtr
Pointer of the data transfer during each DMA write,
DmaWrPtr = 0, 1, 2, . . . , DmaWrLen − 1, for DMA
write of DmaWrLen bytes
CacheFlushCnt
Cache flush count during each D-codewords cycle,
CacheFlushCnt = 0, 1, 2, . . . ,
ceil((N D)/(BurstLen Dmax)) − 1
InRdPtr
Pointer for reading from the input buffer when
performing codeword pre-storage
CacheWrPtr
Pointer for writing into the cache during codeword
pre-storage
CacheRdPtr
Pointer for reading from the cache during codeword
update or internal data transfer
OutWrPtr
Pointer for writing into the output buffer during
codeword extraction
The following is a pseudocode representation of an example algorithm implemented by controller 90 of interleaver 89 :
1. Initialize a D-codewords cycle
a. Set i=0, CacheFlushCnt=0, CacheWrPtr=0. b. If (N D)<(BurstLen Dmax), set UselntBuf=1. Else, set UselntBuf=0.
2. Wait for input codeword
a. Wait until an input codeword is ready from demodulator. b. If (UselntBuf==1), go to step 3. Else, go to step 4.
3. Internal data transfer
a. Read the N-bytes codeword from cache and write directly into output buffer with
OutWrPtr=mod(N-floor(i N/D)+j,N) and CacheRdPtr=mod(i N,D)+j D, for j=0, 1, 2, . . . , N−1.
b. Set InRdPtr=0. c. Go to step 5.
4. DMA read
a. Make a DMA read request of DmaRdLen bytes starting at DmaRdAddr=mod(i N,D) 256 . b. Start DMA data transfer after the request is granted. During the N-bytes data transfer,
the j-th byte is taken from the system memory and written into output buffer with OutWrPtr=mod(Nfloor(i N/D)+j,N), for j=0, 1, 2, . . . , N−1. Once j reaches CacheFlushCnt DmaWrLen, use the data from cache at CacheRdPtr=mod(i N,D)+mod(j,DmaWrLen) D in lieu of the data from the system memory. Continue the replacement until OutWrPtr reaches 0.
c. Set InRdPtr=0.
5. Codeword pre-storage
a. While (InRdPtr<N and CacheWrPtr<BurstLen Dmax), take one codeword byte
in the input buffer and write into the cache. Set InRdPtr=InRd+1, CacheWrPtr=CacheWrPtr+1 after each byte extraction.
b. If ((InRdPtr==N and i<D−1) or (UselntBuf==1)), go to step 7. Else, go to step 6.
6. Cache flush
a. Set DmaWrRqCnt=0. b. While (DmaWrRqCnt<D), make a DMA write of min(DmaWrLen,N-CacheFlushCnt DmaWrLen) bytes starting at DmaWrAddr=CacheFlushCnt DmaWrLen+DmaWrRqCnt 256. During the DMA
transfer, each byte is read from the cache and written into system memory with CacheRdPtr=DmaWrPtr D+DmaWrRqCnt. After the DMA transfer, set DmaWrRqCnt=DmaWrRqCnt+1.
c. Set CacheWrPtr=0. d. If (InRdPtr<N), go to step 5. Else, go to step 7.
7. Output ready
a. Set i=i+1 and signal output ready. b. If (i==D), go to step 1. Else, go to step 2.
Since specifications for ADSL/ADSL2/ADSL2+limit acceptable values of interleaving depth D to one of the set {2, 4, 8, 16, 32, 64 . . . }, algorithm steps above involving dividing by D and mod(D) are easy to implement. Also, with D limited to powers of 2, the DMA read/write length of (BurstLen×Dmax/D) is guaranteed a multiple of the burst length. The pseudocode descriptions of interleaver and deinterleaver controller algorithms listed above assume this limitation on interleaving depth. However in general, D may not be restricted to these power of 2 and in that case, the DMA read/write length of (BurstLen×Dmax/D) should be modified to (BurstLen×ceil(Dmax/D)).
In implementing the above-described algorithm for controller 40 of FIG. 5 , controller 40 causes DMA controller 44 to write every byte of each incoming sequence word in input buffer 42 to main memory 46 , and to also write bytes of that incoming word needed to complete output sequence words residing in cache memory 50 directly to the cache memory. Thus some of the bytes DMA controller 44 write to main memory 46 will not be needed later when they are subsequently read back out of main memory 46 . The redundant bytes are nonetheless written to and read from main memory 96 because it allows the controller algorithm to be less complicated. However, in alternative embodiments of the invention, controller 40 can be programmed to cause DMA controller 44 to write to main memory 46 only those bytes of the word stored in input buffer 42 that are not directly written into cache memory 50 . This modification further increases DMA write transfer efficiency by eliminating the need to write redundant bytes, and also decreases the minimum number of byte storage locations main memory 46 needs by the amount of the available space (BurstLen×Dmax) in cache memory 50 .
In implementing the above-described algorithm for controller 90 of deinterleaver 89 of FIG. 7 , controller 90 transfers every byte of every outgoing sequence word stored in main memory 96 to output buffer 102 . However some of the bytes read from main memory 96 are not up-to-date and have to be replaced by bytes from cache memory 100 representing some of the most recently arrived bytes. Therefore, those redundant bytes need not be read from main memory 96 since they are not up-to-date. Accordingly, in alternative embodiments of the invention, only bytes that needed in output sequence words not yet generated are read from main memory 96 when constructing bytes of the next outgoing word. This further increases both DMA read transfer efficiency by eliminating the need to transfer redundant bytes out of main memory 96 and also decreases the necessary size of main memory by the size (BurstLen×Dmax) of the cache memory.
Thus, the invention provides a reduction of internal memory size over that required by the prior art interleavers or deinterleavers employing only internal memory. For each interleaving data path, the internal memory requirement is reduced from (Nmax×Dmax) bytes to (BurstLen×Dmax) bytes for a savings of (Nmax−BurstLen)′Dmax bytes. For example for ADSL2/ADSL2+, where four interleaving data paths are required, the total internal memory savings is (255-16) ×64=48896 bytes.
The pre-fetch/pre-store function of the internal cached also permits every byte read or written from or to the external memory through DMA to be used, except for only the relatively few bytes that are overwritten by bytes that must be obtained from recently arrived incoming words before they are written into the main memory. Thus, the cache memory helps to increase DMA transfer efficiency over that of the prior art interleavers or deinterleavers employing only external memory.
The specification herein above and the drawings describe exemplary embodiments of best modes of practicing the invention, and elements or steps of the depicted best modes exemplify the elements or steps of the invention as recited in the appended claims. However the appended claims are intended to apply to any mode of practicing the invention comprising the combination of elements or steps as described in any one of the claims, including elements or steps that are functional equivalents of the example elements or steps of the exemplary embodiments of the invention depicted in the specification and drawings. | An apparatus for receiving and storing an incoming sequence and for forwarding the bytes of the incoming sequence as an outgoing sequence in a different byte order includes a cache memory and a main memory for storing bytes of the incoming sequence until they can be forwarded as bytes of the outgoing sequence. A control circuit selectively burst mode writes sequences of incoming bytes that need be stored for a relatively long time to blocks of sequential addresses of the main memory, writes individual bytes of the incoming sequence that need be stored for a relatively short time to selected addresses of the cache memory, and reads bytes out of the cache memory and the main memory when needed to form the outgoing sequence. | 7 |
RELATED APPLICATIONS
[0001] This invention claims priority to U.S. Prov. Pat. App. Ser. No. 60/825,857, attorney docket number 17720, entitled “Header Float Arm Load Compensation”, which was filed on Sep. 15, 2006 by the same inventors.
FIELD OF THE INVENTION
[0002] This invention relates generally to harvesters. More particularly, it relates to conveying systems for conveying cut crop material to the harvester vehicle.
BACKGROUND OF THE INVENTION
[0003] Harvesters have headers (typically called “Draper platforms”) that carry cut crop material on conveyor belts. These conveyor belts extend across the width of the header to a central discharge region of the header. The conveyor belts are supported on rollers that, in turn, are mounted on header float arms that are elongated and extend forwardly. These arms are pivotally mounted to a frame of the header. The forward ends of the header float arms are coupled to and support a cutter bar that extends across the width of the header.
[0004] The cutter bar and/or the forward ends of the arms skid across the surface of the ground as the harvester goes through the field harvesting crop. As the harvester is driven through the field, the ground rises and falls underneath the header and the arms pivot up and down responsibly, thereby permitting the cutter bar to follow the contours of the ground more closely.
[0005] If the cutter bar and/or the front ends of the arms apply too much pressure to the ground they will dig into the ground and be damaged. Controlling the downforce is therefore important in keeping the header and harvester operating properly.
[0006] To reduce the downforce applied by the header to the ground, each arm is partially supported by a hydraulic, pneumatic, or mechanical spring. The springs are coupled to the frame of the header and transmit some of the crop weight to the frame. They do this by exerting a lifting or “up” force on the arms that counteracts the weight of the arms and the additional downforce exerted on the arms by the cut crop material that falls backward onto the conveyor belts after it is cut by the cutter bar. The springs transfer some of the weight of the header float arms and cut crop material to the feeder house on which the header is supported and transfer the weight off the cutter bar and ground.
[0007] The cut crop material is not evenly distributed across the width of the header conveyors. The crop is cut by the cutter bar across the entire front of the header and then falls backwards onto the conveyor belts, a left conveyor belt and a right conveyor belt. The left conveyor belt carries the cut crop material from the left side of the header to the center section of the header, and the right conveyor belt carries the cut crop material from the right side of the header to the center section of the header. Once the cut crop material reaches the center section of the header, the left and right conveyors dump the cut crop material into a center conveyor that carries the cut crop material backwards, through the feeder house, and into the self-propelled vehicle portion of the harvester.
[0008] Depending upon its position across the front of the header, each header float arm needs a different amount of upward counterbalancing force in order that each header float arm exerts the same downforce against the ground that all the other header float arms do. In the ideal situation, each header float arm provides the same, optimal downforce against the ground.
[0009] In order for each header float arm to provide the same downforce against the ground, each spring must apply a different upforce to its associated header float arms. This is necessary since different portions of the conveyor (and hence each header float arm) support different quantities of cut crop material. As the conveyors move laterally across the width of the header toward the lateral midpoint of the header, more and more cut crop material falls onto the conveyor belt. And the header float arms closer to the lateral midpoint of the header carry a greater and greater weight of cut crop material. This additional crop material resting on the header float arms closer to the lateral midpoint or center of the header means that the header float arms closer to the lateral midpoint require a greater counterbalancing upforce—the force exerted by the springs—if each header float arm is to apply a constant downforce against the ground.
[0010] What is needed, therefore, is a control system for applying to each header float arm in the header a counterbalancing upforce that is appropriate to support the crop load and to maintain constant the downforce exerted by each header float arm against the ground (either directly, or through the cutter bar). It is an object of this invention to provide such a system.
SUMMARY OF THE INVENTION
[0011] in accordance with the first aspect of the invention of float arm load compensation system for a header of an agricultural harvester is provided, comprising a header frame; a plurality of header float arms pivotally coupled to the header frame; a cutter bar fixed to forward ends of the plurality of header float arms; at least one conveyor belt supported on the plurality of header float arms and configured to traverse the header perpendicular to the direction of travel of the header, wherein the conveyor belt is further configured to receive crop material cut by the cutter bar; and a plurality of springs, wherein each spring is coupled to an associated header float arm of the plurality of header float arms to exert a force on the associated header float arm compensating for the weight of cut crop material supported by the associated header float arm.
[0012] The springs of the plurality of springs that support float arms closer to the lateral midpoint of the header may be configured to exert a greater upforce on their associated header float arms than other springs of the plurality of springs that support float arms farther from the lateral midpoint of the header. The plurality of springs may be configured to maintain constant the downforce exerted by their associated header float arms against the ground across a width of the header. The load compensation system may further include a control circuit configured to monitor an operational parameter of the agricultural harvester indicative of the load on the at least one conveyor belt. The control circuit may monitor an operational parameter indicative of a load on the rotor of the harvester. The control circuit may be configured to automatically change the forces exerted by the plurality of springs on their associated header float arms in response to changes in the operational parameter. The load compensation system may further include an accumulator containing gas charged hydraulic fluid coupled to the plurality of springs. The load compensation system may further include a valve configured to simultaneously change the force is applied by the plurality of springs by filling and emptying the accumulator. The load compensation system may further include at least first and second accumulators containing hydraulic fluid under pressure, wherein the first accumulator is coupled to a first group of springs of the plurality of springs, and wherein the second accumulator is coupled to a second group of springs of the plurality of springs. The plurality of springs may be mechanical springs. The mechanical springs may be coil springs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a plan view of a harvester having a header in the form of a Draper platform in accordance with the present invention.
[0014] FIG. 2 is a side view of the harvester of FIG. 1 .
[0015] FIG. 3 is a fragmentary cross-sectional view of the header of FIGS. 1-2 taken at section line 2 - 2 in FIG. 1 .
[0016] FIG. 4 is a schematic diagram of the header of FIGS. 1-3 with alternative springs and a control circuit for controlling the alternative springs.
[0017] FIG. 5 is a schematic diagram of the header of FIG. 4 with an alternative control circuit for controlling the alternative springs.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] An “upforce”, as that term is used herein, refers to a force applied to a header float arm that tends to lift the forward end of the header float arm upward and away from the ground thereby reducing the force of the header float arm against the ground. It does not imply or require that the force itself be directed upward at its point of application to the header float arm. Indeed, depending upon the geometry of the header float arm, the force may be applied to the header float arm in any direction and at any point along the arm.
[0019] Referring now to FIGS. 1-2 , a combine harvester 100 is illustrated, comprising a vehicle 102 that is wheeled and self-propelled, and also comprising a header 104 which is a Draper platform that is mounted on the front of the vehicle 102 .
[0020] Vehicle 102 further comprises a feeder house 106 that is pivotally coupled to the front of chassis 108 of vehicle 102 . Header 104 is supported on the front of feeder house 106 .
[0021] Header 104 comprises a frame 112 , a plurality of arms 114 (identified collectively as header float arms 114 a - j ), a plurality of springs 116 (identified as springs 116 a - j ), conveyor belts 118 , 120 , a center conveyor 122 , and a cutter bar assembly 124 that is fixed to the leading ends of the arms 114 .
[0022] Referring now to FIG. 3 , arms 114 extend fore and aft and are pivotally coupled at their rear ends to frame 112 . This arrangement permits them to pivot about a substantially horizontal and laterally extending axis 126 with respect to frame 112 . This pivotal movement permits the front ends of arms 114 to move up and down with respect to frame 112 as the harvester traverses the ground.
[0023] Each arm has an associated spring 116 (identified collectively as springs 116 a - j ) that is coupled to the arm and to the frame to provide an up will force on its associated arm 114 , thereby reducing the force applied by the arm downward on the ground.
[0024] Each arm supports a roller 128 that is supported at its front and rear ends on arm 114 . Roller 128 is disposed generally parallel to arm 114 and is configured to roll about its longitudinal axis.
[0025] Arms 114 located on the left side of the header 104 centerline support a left side conveyor belt 118 . Left side conveyor belt 118 is driven such that it carries material falling on its top surface inwards towards the center region of header 104 .
[0026] Arms 114 located on the right side of the header 104 centerline support a right side conveyor belt 120 . Right side conveyor belt 120 is driven such that it carries material falling on its top surface inwards towards the center region of header 104 .
[0027] Left side conveyor belt 118 and right side conveyor belt 120 are supported on rollers 128 .
[0028] Cutter bar assembly 124 extends laterally across the width of the header 104 and is fixed to the front ends of arms 114 . A lower portion 130 of cutter bar assembly 124 functions as a skid plate, sliding along the ground as vehicle 102 transports header 104 across the field. A portion of the weight of the arms, the conveyor belts, and the crop material riding on the conveyor belts is communicated to cutter bar assembly 124 and thence to the ground. The remainder of the weight is communicated to feeder house 106 .
[0029] Cutter bar assembly 124 is flexible in the lateral direction to permit individual arms 114 a - j to rise and fall somewhat independently of each other as the cutter bar assembly 124 follows the contours of the ground. This permits the header to more closely follow the contours of the ground. In turn, this close ground-following ensures that the header 104 picks up all of the plant material bearing crop.
[0030] Each arm 114 a - j is provided with a spring 116 a - j that is coupled to the arm and to the frame 112 of the header 104 . Spring 116 may be mechanical, hydraulic, or pneumatic. It applies an upward force to arm 114 a - j , reducing the downforce exerted by arm 114 a - j on the ground via cutter bar assembly 124 . Springs 116 a - j transfer the weight of their associated arms (and the loads they carry) from the ground to frame 112 .
[0031] The force that each spring 116 a - j applies is not the same, however. Springs 116 that are closer to the center of header 104 apply a greater upforce to their associated arms 114 a - j than springs 116 a - j located farther from the center of header 104 . This differential additional upforce applied to arms 114 a - j closer to the center of header 104 compensates for the increased weight of crop material on the conveyor belt 118 , 120 supported on those arms. The weight of the plant material on the conveyor belts 118 , 120 resting on arms 114 a - j changes as more and more crop accumulates on the conveyor belts. The weight of the plant material at the outer ends of the conveyor belts is relatively light. As the conveyor belt (supported on rollers 128 ) moves towards the lateral midpoint of the header 104 , more and more plant material is cut by the cutter bar assembly 124 and falls on the conveyor belts. This builds up a thick layer of cut plant material on the conveyor belt that reaches a maximum thickness when the conveyor belt reaches the lateral midpoint of the header 104 and center conveyor 122 . At this point, conveyor belts 118 , 120 on the left and right sides, respectively, of header 104 deposit their accumulated cut plant material on center conveyor 122 , which moves the cut plant material backward, through feeder house 106 , and into vehicle 102 for further processing.
[0032] In order to maintain a relatively constant downforce across the entire width of the cutter bar assembly 124 , each of the arms 114 a - j is counterbalanced by its associated spring 116 a - j such that each arm 114 a - j applies the same downforce on the section of the cutter bar assembly 124 to which it is attached. This provides an even ground load across the width of the header 104 .
[0033] There are several ways that the springs 116 a - j can be configured to provide different upforces to arms 114 a - j such as by adjusting their mounting locations on the frame of the header or the arms, or by varying up reload to the springs.
[0034] Referring now to FIG. 3 , spring 116 h has an upper end 132 that can be coupled to frame 112 at several different mounting points 134 and a lower end 136 that can be coupled to arm 114 h at several different mounting points 138 . Spring 116 h has a preload adjuster 139 , here shown as an adjustable screw on the barrel of the spring to vary the preload of the spring. By mounting the lower end of spring 116 h closer to the pivot 141 , the ground force at the end of arm 114 h can be increased. By mounting the lower end of spring 116 h farther from the pivot, the ground force at the end of arm 114 h can be decreased. By mounting the upper end of spring 116 h farther upward, the ground force at the end of arm 114 h can be decreased. By mounting the upper end of spring 116 h farther downward, a ground force at the end of arm 114 h can be increased. By increasing the spring preload on spring 116 h , the ground force at the end of arm 114 h can be decreased. By decreasing the spring preload one spring 116 h , the ground force at the end of arm 114 h can be increased. The arrangement of spring 116 h and arm 114 h in FIG. 3 is typical of all the springs 116 a - j and arms 114 a - j in header 104 . The springs 116 a - j are individually adjusted to provide a greater upforce on the arms 114 a - j that are closer to the lateral midpoint or center of header 104 and to provide a smaller upforce on the arms 114 a - j farther from the lateral midpoint or center of header 104 .
[0035] Header 104 of FIGS. 1-3 is divided into several zones, comprising a first zone including the two outer arms 114 a , 114 b on the far left side of the header and the two outer arms 114 i , 114 j on the far right side of the header. A second zone includes the two arms on each side of the header just inside the first zone, 114 c , 114 d , 114 g , 114 h , and the third zone including the two center arms 114 e , 114 f.
[0036] Springs 116 a , 116 b , 116 i , 116 j of the first zone are configured to provide a first upforce to their associated arms. Springs 116 c , 116 d , 116 g , 116 h are configured to provide a second upforce to their associated arms 114 c , 114 d , 114 g , 114 h that is greater than the first upforce applied to the arms in the first zone. This accommodates the additional weight of cut crop matter falling on conveyor belts 118 , 120 as the belts move from the first zone to the second zone.
[0037] Springs 116 e , 116 f are configured to provide a third upforce to their associated arms 114 e , 114 f that is greater than the second upforce applied to the arms in the second zone. This accommodates the additional weight of cut crop matter falling on conveyor belts 118 , 120 as the belts move from the second zone to the third zone.
[0038] In an alternative embodiment, each of the springs 116 a - j is configured to apply an upforce that is greater than the upforce applied to the arm immediately adjacent to it and farther away from the centerline of the vehicle. In other words, the upforce applied by spring 116 e to its arm is greater than that applied by spring 116 d to its arm, which is greater than that applied by spring 116 c to its arm, which is greater than that applied by spring 116 b to its arm which is greater than that applied by spring 116 a to its arm. An upforce applied by spring 116 f to its arm is greater than the upforce applied by spring 116 g to its arm, which is greater than the upforce applied by spring 116 h to its arm, which is greater than the upforce applied by spring 116 i to its arm, which is greater than the upforce applied by spring 116 j.
[0039] One drawback of this arrangement is the need to mechanically adjust each spring 116 a - 116 j for different crops and crop conditions. Any particular adjustment of springs 116 a - j in FIGS. 1-3 anticipates a particular crop load on conveyor belts 118 , 120 . If the actual crop load is different from this, the ground force exerted by each of arms 114 will not be ideal. Indeed, if a very large crop load is expected on conveyor belts 118 , 120 , the compensating upforce generated by springs 116 a - j may be so great that the arms may actually be lifted above the ground if the crop is not as heavy as anticipated and therefore the compensating upforce generated by springs 116 a - j is too great.
[0040] To provide easier adjustment of the upforces generated by springs 116 a - j , other spring arrangements may be employed. In FIG. 4 , for example, each of springs 116 a - j is a hydraulic cylinder. Springs 116 a - j in FIG. 4 are all coupled to an accumulator that is gas charged and contains hydraulic fluid under pressure. This pressure is applied equally to all of the springs 116 a - j in FIG. 4 . In one arrangement, springs 116 a - j exert an equal upforce on their associated arms 114 a - j to counterbalance the weight of the arm 114 a - j and the weight of the crop material on conveyor belts 118 , 120 that the arms support. In an alternative arrangement, springs 116 a - j in FIG. 4 are configured to exert different upforces on their associated arms 114 a - j to counterbalance the weight of the arm 114 a - j and the weight of the crop material on conveyor belts 118 , 120 that the arms support. In this alternative arrangement, the upforces exerted by springs 116 a - j on arms 114 a - j may be divided into multiple zones, such as the three zones described above with regard to the header 104 of FIGS. 1-3 . Alternatively the upforces exerted by springs 116 a - j on arms 114 a - j may be arranged such that the upforce generated by spring 116 e is greater than the force generated by spring 116 d , which is greater than the force generated by spring 116 c , which is greater than the force generated by spring 116 b , which is greater than the force generated by spring 116 a . The upforce generated by spring 116 f is greater than the upforce generated by spring 116 g , which is greater than the upforce generated by spring 116 h , which is greater than the upforce generated by spring 116 i to its arm, which is greater than the upforce generated by spring 116 j to its arm.
[0041] In order to generate different upforces when the hydraulic fluid pressure applied to each of the springs 116 a - j is the same, springs 116 a - j may be made with different piston diameters, or alternatively may be coupled to arms 114 a - j and frame 112 of header 104 at different locations with different mechanical advantages, such as at the different locations along the arms and the frame shown in FIG. 3 .
[0042] In the arrangement of FIG. 4 , the amount of upforce generated by all of the springs 116 a - j can be varied simultaneously by filling or emptying the accumulator 132 . A valve 134 is provided that is coupled to a hydraulic fluid supply 136 and a hydraulic fluid reservoir 138 . The valve 134 , when opened, can selectively empty hydraulic fluid from the accumulator 132 to the hydraulic fluid reservoir 138 , or fill the accumulator 132 with hydraulic fluid from the hydraulic fluid supply 136 . As the accumulator 132 is emptied, the pressure in the accumulator 132 , and hence the pressure in each of springs 116 a - j decreases. As the accumulator 132 is filled, the pressure in the accumulator 132 and hence the pressure in each of springs 116 a - j increases. The change in pressure in springs 116 a - j causes a proportional change in the upforce applied by the springs to arms 114 a - j . Thus, by changing the fluid in the accumulator 132 , all of the compensating upforces applied to arms 114 a - j are simultaneously and proportionally changed across the width of header 104 .
[0043] Electronic control unit (ECU) 140 is coupled to the valve 134 to selectively fill or empty the accumulator 132 under computer control. Electronic control unit 140 is preferably a microprocessor based digital computer including the memory circuit containing a program configured to perform all functions of the electronic control unit described herein. A sensor 142 is coupled to the electronic control unit 140 to transmit to the electronic control unit 140 a value indicative of a desired compensating upforce to be generated by springs 116 a - j . In one embodiment, the sensor 142 is a rotor load sensor, responsive to and indicative of the load on a threshing rotor in the vehicle 102 (not shown). In another embodiment, the sensor is a strain gauge coupled to a rotor drive element such as a rotor shaft or gear responsive to and indicative of the load on the rotor. In another embodiment, the sensor is a pressure sensor responsive to and in indicative of the hydraulic pressure in the hydraulic circuit driving the rotor. In another embodiment, the sensor is a pressure sensor responsive to and indicative of the hydraulic pressure in the hydraulic circuit that drives conveyor belts 118 , 120 . In another embodiment, the sensor is a load sensor responsive to and indicative of the weight of conveyor belts 118 , 120 . In any of these embodiments, the sensed parameter is indicative of the load on the harvester, and hence the volume of crop material being harvested. The volume of crop material being harvested is indicative of the weight of the crop material. The weight of the crop material is indicative of the downforce exerted by arms 114 a - j and thus is indicative of the desired compensating upforce each spring 116 a - j needs to apply to its associated arm 114 a - j to maintain the downforce exerted by arms 114 a - j on the cutter bar (and hence the force the cutter bar and arms exert on the ground). The electronic control unit 140 is configured to monitor the sensor and to open the valve an amount appropriate to maintain constant the downforce exerted by arms 114 a - j on the cutter bar (and hence the force the cutter bar and arms exert on the ground).
[0044] In another embodiment, the sensor 142 is configured to sense the position of an operator input device, for example a joystick, knob, dial, or lever, that the operator uses to directly command a desired compensating upforce. In this arrangement, the operator monitors the crop load and selects the desired upforce to be generated by springs 116 a - j . Once the operator has selected the desired upforce, he adjusts the operator input device to indicate the desired upforce. The sensor 142 is responsive to this change in the operator input device and signals the electronic control unit. The electronic control unit 140 , in turn, is programmed to open or close the valve 134 as necessary to generate the desired upforce. In this manner, and even while the vehicle is underway, the operator can simultaneously adjust the desired upforce of all the springs 116 a - j.
[0045] FIG. 5 illustrates another embodiment of the system in which a different control circuit is provided to control the operation of springs 116 a - j , the control circuit including three accumulators 144 , 146 , 148 to apply a different hydraulic pressure to three different groups of springs 116 a - j . This embodiment is the same as the embodiment of FIG. 4 in all respects, except the control circuit includes three valves and three accumulators to apply three different pressures to three different groups of valves 116 a - j . In the embodiment of FIG. 5 , the control circuit includes a first accumulator 144 containing gas charged hydraulic fluid that is coupled to springs 116 a , 116 b , 116 i , and 116 j . A second accumulator 146 containing gas charged hydraulic fluid is coupled to springs 116 c , 116 d , 116 g , and 116 h . A third accumulator 148 containing gas charged hydraulic fluid is coupled to springs 116 e and 116 f . These three groups of springs 116 a - j define three different zones of the header 104 . These three accumulators are coupled to a first valve 150 , a second valve 152 , and a third valve 154 , respectively that conduct hydraulic fluid to and from their respective accumulators 144 , 146 , 148 . Each of the three valves 144 , 146 , 148 are also coupled to the hydraulic fluid supply 136 and the hydraulic fluid reservoir 138 . As in the example of FIG. 4 , the electronic control unit 140 opens and closes the valves responsive to the signal provided by the sensor 142 in order to maintain constant a desired downforce exerted by arms 114 a - j and the cutter bar on the ground. In the embodiment of FIG. 5 , however, the electronic control unit 140 is separately coupled to each of the three valves 150 , 152 , 154 such that it can change the hydraulic pressure in each of the three zones independently of the hydraulic pressure in the other zones.
[0046] Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. | A float arm load compensation system for a header of an agricultural harvester includes a header frame; a plurality of header float arms pivotally coupled to the header frame; a cutter bar fixed to forward ends of the plurality of header float arms; at least one conveyor belt supported on the plurality of header float arms and configured to traverse the header perpendicular to the direction of travel of the header, wherein the conveyor belt is further configured to receive crop material cut by the cutter bar; and a plurality of springs, wherein each spring is coupled to an associated header float arm of the plurality of header float arms to exert a force on the associated header float arm compensating for the weight of cut crop material supported by the associated header float arm. | 0 |
[0001] This application claims the benefit of
[0000] U.S. Provisional Application No. 62/055,381, entitled “Signalling for Inter-eNB CoMP,” filed on Sep. 25, 2014,
U.S. Provisional Application No. 62/056,095, entitled “Signalling for Inter-eNB CoMP,” filed on Sep. 26, 2014,
U.S. Provisional Application No. 62/076,221, entitled “CSI Exchange for Inter-eNB CoMP,” filed on Nov. 6, 2014,
U.S. Provisional Application No. 62/076,873, entitled “CSI Exchange for Inter-eNB CoMP,” filed on Nov. 7, 2014,
U.S. Provisional Application No. 62/110,006, entitled “CSI Exchange for Inter-eNB CoMP,” filed on Jan. 30, 2015,
U.S. Provisional Application No. 62/145,251, entitled “Efficient CSI and e-RNTP Exchange for Inter-eNB CoMP,” filed on Apr. 9, 2015,
U.S. Provisional Application No. 62/145,580, entitled “Efficient CSI and e-RNTP Exchange for Inter-eNB CoMP,” filed on Apr. 10, 2015,
U.S. Provisional Application No. 62/150,178, entitled “CSI Exchange for Inter-eNB CoMP,” filed on Apr. 20, 2015,
U.S. Provisional Application No. 62/151,796, entitled “Subband Definitions and eRNTP enhancements,” filed on Apr. 23, 2015,
U.S. Provisional Application No. 62/161,804, entitled “On the Subband Definition in CSI Signaling,” filed on May 14, 2015,
U.S. Provisional Application No. 62/162,285, entitled “eRNTP Signalling for Inter-eNB CoMP,” filed on May 15, 2015,
U.S. Provisional Application No. 62/204,541, entitled “Subband definition in CSI Signaling,” filed on Aug. 13, 2015,
the contents of all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to coordinated multi-point transmission and reception (CoMP) in wireless or mobile communications and, more particularly, to signalling in inter-eNB (E-UTRAN NodeB or eNodeB) CoMP.
[0003] Referring now to FIG. 1 , a CoMP mobile communications system 400 comprising a CoMP coordination zone or area or CoMP cooperating set 402 in which the embodiments may be implemented is illustrated. One or more user equipments (UEs) 410 are served by one or more TPs or cells 404 to 408 . TPs 404 to 408 can be base stations or eNBs. Each of the user equipments includes e.g. a transmitter and a receiver, and each of the base stations or eNBs 104 includes e.g. a transmitter and a receiver.
[0004] Transmission layers are sometimes called “transmit layers” or “layers.” The number of transmission layers is known as “transmission rank” or “rank.” A codebook is a set of precoding matrices or precoders. A precoding matrix is also known as a codeword.
REFERENCE
[0000]
[1] RP-141032, “New Work Item on Enhanced Signaling for Inter-eNB CoMP,” June 2014.
[2] R3-142582, “Way forward on WI: Enhanced signalling for inter-eNB CoMP,” October 2014.
[3] R1-141206, “Signaling Considerations for Inter-eNB CoMP”, NEC, March 2014.
[4] R3-151209, Change Request, May 2015.
BRIEF SUMMARY OF THE INVENTION
[0009] An objective of the present invention is to provide efficient channel state information (CSI) and/or relative narrowband Tx (transmit) power (RNTP) exchanges between eNBs.
[0010] An aspect of the present invention includes, in a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP). The wireless communications method comprises, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, receiving from the second base station a plurality of CSI reports each of which comprises a rank indication (RI) and a channel quality indicator (CQI), wherein the second base station receives from one or more user equipments (UEs) RI and CQI information.
[0011] Another aspect of the present invention includes, in a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the second base station supporting coordinated multi-point transmission and reception (CoMP). The wireless communications method comprises receiving from one or more user equipments (UEs) rank indication (RI) and channel quality indicator (CQI) information, and for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, transmitting to the first base station a plurality of CSI reports each of which comprises an RI and a CQI.
[0012] Still another aspect of the present invention includes a first base station supporting coordinated multi-point transmission and reception (CoMP) and used in a wireless communications system. The first base station comprises a receiver to receive from a second base station, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, a plurality of CSI reports each of which comprises a rank indication (RI) and a channel quality indicator (CQI), wherein the second base station receives from one or more user equipments (UEs) RI and CQI information.
[0013] Still another aspect of the present invention includes a second base station supporting coordinated multi-point transmission and reception (CoMP) and used in a wireless communications system. The second base station comprises a receiver to receive from one or more user equipments (UEs) rank indication (RI) and channel quality indicator (CQI) information, and a transmitter to transmit to a first base station, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, a plurality of CSI reports each of which comprises an RI and a CQI.
[0014] Still another aspect of the present invention includes a wireless communications method implemented in a wireless communications system supporting coordinated multi-point transmission and reception (CoMP) and including a first base station and a second base station. The wireless communications comprises transmitting from one or more user equipments (UEs) to the second base station rank indication (RI) and channel quality indicator (CQI) information, and for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, transmitting from the second base station to the first base station a plurality of CSI reports each of which comprises an RI and a CQI.
[0015] Still another aspect of the present invention includes a wireless communications system supporting coordinated multi-point transmission and reception (CoMP). The wireless communications system comprises a first base station, a second base station transmitting to the first base station, for a given user equipment (UE) identification (ID) and a given channel state information (CSI) process, a plurality of CSI reports each of which comprises a rank indication (RI) and a channel quality indicator (CQI), and one or more user equipments (UEs) transmitting to the second base station RI and CQI information.
[0016] An aspect of the present invention includes, in a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP). The wireless communications method comprises receiving from the second base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, and performing interference aware scheduling.
[0017] Another aspect of the present invention includes, in a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the second base station supporting coordinated multi-point transmission and reception (CoMP). The wireless communications method comprises transmitting to the first base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, wherein the first base station performs interference aware scheduling.
[0018] Still another aspect of the present invention includes a first base station supporting coordinated multi-point transmission and reception (CoMP) and used in a wireless communications system. The first base station comprises a receiver to receive from the second base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, and a controller to perform interference aware scheduling.
[0019] Still another aspect of the present invention includes a second base station supporting coordinated multi-point transmission and reception (CoMP) and used in a wireless communications system. The second base station comprises a transmitter to transmit to the first base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, wherein the first base station performs interference aware scheduling.
[0020] Still another aspect of the present invention includes a wireless communications method implemented in a wireless communications system supporting coordinated multi-point transmission and reception (CoMP) and including a first base station and a second base station. The wireless communications comprises transmitting from the second base station to the first base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, and performing at the first base station interference aware scheduling.
[0021] Still another aspect of the present invention includes a wireless communications system supporting coordinated multi-point transmission and reception (CoMP). The wireless communications system comprises a first base station, and a second base station transmitting to the first base station an information element (IE) indicating multiple relative narrowband Tx (transmit) power (RNTP) thresholds, wherein the first base station performs interference aware scheduling.
[0022] An aspect of the present invention includes, in a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP). The wireless communications method comprises receiving, from the second base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, and using the UE ID to link the RSRP report with another measurement result for the UE.
[0023] Another aspect of the present invention includes, in a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the second base station supporting coordinated multi-point transmission and reception (CoMP). The wireless communications method comprises transmitting, to the first base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, wherein the first base station uses the UE ID to link the RSRP report with another measurement result for the UE.
[0024] Still another aspect of the present invention includes a first base station supporting coordinated multi-point transmission and reception (CoMP) and used in a wireless communications system. The first base station comprises a receiver to receive, from the second base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, and a controller to use the UE ID to link the RSRP report with another measurement result for the UE.
[0025] Still another aspect of the present invention includes a second base station supporting coordinated multi-point transmission and reception (CoMP) and used in a wireless communications system. The second base station comprises a transmitter to transmit to the first base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, wherein the first base station uses the UE ID to link the RSRP report with another measurement result for the UE.
[0026] Still another aspect of the present invention includes a wireless communications method implemented in a wireless communications system supporting coordinated multi-point transmission and reception (CoMP) and including a first base station and a second base station. The wireless communications comprises transmitting, from the second base station to the first base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, and using at the first base station the UE ID to link the RSRP report with another measurement result for the UE.
[0027] Still another aspect of the present invention includes a wireless communications system supporting coordinated multi-point transmission and reception (CoMP). The wireless communications system comprises a first base station, and a second base station transmitting to the first base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, wherein the first base station uses the UE ID to link the RSRP report with another measurement result for the UE.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 depicts a block diagram of a CoMP system.
DETAILED DESCRIPTION
Embodiment A
[0029] A1. Introduction
[0030] In the following we provide our views on channel state information (CSI) and enhanced relative narrowband Tx (transmit) power (eRNTP) exchange as well as proposals containing the required message structure.
[0031] A2. Discussion
[0032] A2.1 CSI Exchange
[0033] One eNB can send CSI report pertaining to one or more of its users to a neighboring eNB.
[0034] For each UE the CSI that the eNB sends can comprise:
[0035] CQI (channel quality indication): up-to 2 CQIs, each including a wideband CQI or component and possible sub-band differential CQIs or components
[0036] RI: wideband component
[0037] We note that the PMI was excluded from the CSI exchange report. The justification for this exclusion was to minimize the overhead and the fact that PMI can depend on fast changing channel information, thus reducing its utility over non ideal backhaul with a higher latency. However, in the absence of PMI the use of RI is limited. Indeed, any rank greater than 1 will convey only 2 CQIs, one for each of the two codewords. No further information about the (average) spatial directions seen by that user can be deduced by the eNB receiving the report. As a result, reporting the RI should be made optional. Moreover, the eNB requesting the CSI report should be able to able to specify whether or not it would like to receive RI reports. This can be achieved by setting a bit (for instance in the CSI Measurement Report type field) to be 0 if rank is not requested and 1 otherwise. Similarly, the eNB requesting the CSI reports should be able to specify whether or not it requires subband specific CQI reports. Another bit can be set to 0 if subband CQIs are not requested and 1 otherwise. The response of the eNB receiving the request can be mandated to comply with this request, i.e., that eNB can decide to include a rank indication in its response only if it is requested in the CSI measurement report type field of the corresponding request. Further, the subband specific CQI can be included only if they are requested in the CSI measurement report type field of the corresponding request.
[0038] In this context, we note that a CSI process can be defined to be the reference process for another one. In that case the latter process will reuse the rank determined for its reference process. It can be beneficial to exploit reference rank in the X2 signalling as well. One way to achieve this is to include another bit in the CSI Measurement Report type field which specifies whether or not a single rank is requested. In particular, this bit can be set to 1 only if the rank request bit is also set to 1. In that case the eNB receiving the request should understand that the requesting eNB is requesting CSI reports where only one rank is reported for each user. The response of the eNB receiving the request can be mandated to comply with this request, i.e., if the eNB decides to include a rank indication in its response then it has to be one indication per user.
[0039] Alternatively, no such mandate can be enforced, in which case it is up-to the eNB whether or not to include a rank indication in the CSI corresponding to each CSI-process of each user and the ranks indicated for a particular user need not be identical.
[0040] One of the goals of CSI exchange was to facilitate centralized RRM. In a scenario with centralized RRM, the central node receiving the CSI reports should be able to keep track of the CSI information received for each particular UE, over all the received CSI reports. This can be achieved by including a UE identifier in each CSI report for each UE whose CSI is conveyed in that report.
[0041] Moreover, for each CSI in the report, the CSI process configuration information should be included in order to convey the conditions under which the CSI was measured by the UE. This configuration information includes non-zero power CSI-RS information and IMR information (including, for example, the subframe indices and zero-power CSI-RS information). Since this configuration is anyway informed to the UE via higher layer signaling, for instance CSI-RS in tables 7.2.6 of TS36.213, and tables 6.10.5.2-1, 6.10.5.2-2 of TS36.211 and subframe indices in tables 7.2.6 of TS36.213, and table 6.10.5.3-1 of TS36.211, the same signaling can be reused to convey the configuration to the neighboring eNB. Another way of conveying this configuration information is through a look-up-table. A look-up-table mapping an index to each distinct applied CSI process configuration can be constructed for each eNB. Here, by an applied CSI process we mean a process that is used by at-least one served UE to measure its CSI. Such a table can be conveyed beforehand by it to eNB1, and then each report can include an index which will inform. Such a table can also be exchanged among neighbor eNBs first, and then the configuration information can be exchanged via indices.
[0042] We note that the period specified in the request by eNB1 to a neighboring eNB2 (via the Reporting Periodicity of CSI Measurement Report field) can be different from the periodicity with which the CSI is measured by a UE as per a CSI process, and then reported (over the air) to eNB2. To address such scenarios, eNB2 can either subsample (for example select the most recently received CSI) or average (over all CSIs received after those considered while determining the previous response) and send its response to eNB1, for example, about the CSI process configuration information. Note that the averaging can be done over the CQIs for a given codeword, given rank and given subband. The most recent received rank can be used for averaging.
[0043] A2.2 eRNTP Exchange
[0044] Our view on eRNTP exchange is captured in a corresponding proposal.
[0045] We note that the RNTP for the first subframe is always conveyed. If no information about the downlink (DL) power restriction on any subsequent subframe is conveyed, then the one conveyed for the first subframe can be assumed to remain static (i.e., applicable over subsequent subframes).
[0046] A3. Conclusion
[0047] We discussed the necessary X2 message to support CSI and eRNTP exchange for inter-eNB CoMP and presented corresponding proposals.
[0048] Proposals
[0049] 9.1.2.1 Load Information
[0050] This message is sent by an eNB to neighbouring eNBs to transfer load and interference co-ordination information.
[0051] Direction: eNB 1 →eNB 2 .
[0000]
TABLE A1
IE type
and
Semantics
Assigned
IE/Group Name
Presence
Range
reference
description
Criticality
Criticality
Message Type
M
9.2.13
YES
ignore
Cell Information
M
YES
ignore
>Cell Information
1 . . . <maxCellineNB>
EACH
ignore
Item
>>Cell ID
M
ECGI
Id of the
—
—
9.2.14
source cell
>>UL
O
9.2.17
—
—
Interference
Overload
Indication
>>UL High
0 . . . <maxCellineNB>
—
—
Interference
Information
>>>Target Cell
M
ECGI
Id of the cell
—
—
ID
9.2.14
for which the
HII is meant
>>>UL High
M
9.2.18
—
—
Interference
Indication
>>Relative
O
9.2.19
—
—
Narrowband Tx
Power (RNTP)
>>ABS
O
9.2.54
YES
ignore
Information
>>Invoke
O
9.2.55
YES
ignore
Indication
>>Intended
O
ENUMERATED
One of the
YES
ignore
UL-DL
(sa0, sa1,
UL-DL
Configuration
sa2, sa3,
configurations
sa4, sa5,
defined in
sa6, . . . )
TS 36.211
[10]. The UL
subframe(s)
in the
indicated
configuration
is subset of
those in
SIB1 UL-DL
configuration.
This IE
applies to
TDD only.
>>Extended UL
O
9.2.67
This IE
YES
ignore
Interference
applies to
Overload Info
TDD only.
>>Enhanced
O
9.2.x2
YES
ignore
Relative
Narrowband Tx
Power (eRNTP)
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value is 256.
[0052] 9.1.2.11 Resource Status Request
[0053] This message is sent by an eNB 1 to a neighbouring eNB 2 to initiate the requested measurement according to the parameters given in the message.
[0054] Direction: eNB 1 →eNB 2 .
[0000]
TABLE A2
IE type
IE/
and
Semantics
Assigned
Group Name
Presence
Range
reference
description
Criticality
Criticality
Message Type
M
9.2.13
YES
reject
eNB1
M
INTEGER
Allocated by eNB 1
YES
reject
Measurement
(1 . . . 4095, . . . )
ID
eNB2
C-ifRegistrationRequestStop
INTEGER
Allocated by eNB 2
YES
ignore
Measurement
(1 . . . 4095, . . . )
ID
Registration
M
ENUMERATED
A value set to
YES
reject
Request
(start,
“stop”, indicates a
stop, . . . )
request to stop all
cells
measurements.
Report
O
BITSTRING
Each position in
YES
reject
Characteristics
(SIZE(32))
the bitmap
indicates
measurement
object the eNB 2 is
requested to
report.
First Bit = PRB
Periodic,
Second Bit = TNL
load Ind Periodic,
Third Bit = HW
Load Ind Periodic,
Fourth Bit =
Composite
Available Capacity
Periodic, this bit
should be set to 1 if
at least one of the
First, Second or
Third bits is set to
1,
Fifth Bit = ABS
Status Periodic,
Xth Bit = UE-CSI
Periodic.
Other bits shall be
ignored by the
eNB 2 .
Cell To Report
1
Cell ID list for
YES
ignore
which
measurement is
needed
>Cell To
1 . . . <maxCellineNB>
EACH
ignore
Report Item
>>Cell ID
M
ECGI
—
—
9.2.14
Reporting
O
ENUMERATED
YES
ignore
Periodicity
(1000 ms,
2000 ms,
5000 ms,
10000 ms, . . . )
Partial Success
O
ENUMERATED
Included if partial
YES
ignore
Indicator
(partial
success is allowed
success
allowed, . . . )
CSI
O
BITSTRING
Each position in
YES
ignore
Measurement
(SIZE(2))
the bitmap
Report type
indicates the type
of CSI
measurement to
report.
First bit = Rank,
Second
bit = subband CQI.
Reporting
O
ENUMERATED
Periodicity for CSI
YES
ignore
Periodicity
(5 ms,
Measurement
of CSI
10 ms,
Report Periodic
Measurement
20 ms, 40 ms,
Report
80 ms,
aperiodic, . . . )
Explanation
Range bound
maxCellineNB
Maximum no. cells that can be served by an eNB. Value is 256.
Condition
ifRegistrationRequestStop
This IE shall be present if the Registration Request IE is set to the
value “stop”.
[0055] 9.1.2.14 Resource Status Update
[0056] This message is sent by eNB 2 to neighbouring eNB 1 to report the results of the requested measurements.
[0057] Direction: eNB 2 →eNB 1 .
[0000]
TABLE A3
IE type
and
Semantics
Assigned
IE/Group Name
Presence
Range
reference
description
Criticality
Criticality
Message Type
M
9.2.13
YES
ignore
eNB1
M
INTEGER
Allocated by
YES
reject
Measurement ID
(1 . . . 4095, . . . )
eNB 1
eNB2
M
INTEGER
Allocated by
YES
reject
Measurement ID
(1 . . . 4095, . . . )
eNB 2
Cell Measurement
1
YES
ignore
Result
>Cell
1 . . . <maxCellineNB>
EACH
ignore
Measurement
Result Item
>>Cell ID
M
ECGI
9.2.14
>>Hardware
O
9.2.34
Load Indicator
>>S1 TNL Load
O
9.2.35
Indicator
>>Radio
O
9.2.37
Resource Status
>>Composite
O
9.2.44
YES
ignore
Available
Capacity Group
>>ABS Status
O
9.2.58
YES
ignore
>>UE-CSI
O
9.2.x1
YES
ignore
Report
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value is 256.
[0058] 9.2.x1 UE-CSI Report
[0059] This information element (IE) provides UE-CSI information for a subset or set of UEs served by eNB 2 .
[0000]
TABLE A4
IE type and
IE/Group Name
Presence
Range
reference
Semantics description
UE subset CSI Report
1 . . .
<maxUEsubsetCSIReport>
>C-RNTI
M
BIT STRING
ID of the UE served by
(SIZE (16))
the cell in eNB 2 .
Defined in TS 36.331.
>UE-CSI process
1 . . .
information
<maxUE-CSIprocess>
>>Rank Indicator
O
INTEGER
The rank indicator is
(1 . . . 8, . . . )
present only if it is
or BIT STRING
requested in the
(SIZE (3))
associated request.
Cf. TS 36.213 [7.2.3].
>>Wideband CQI For
M
INTEGER
Cf. TS 36.213 [7.2.3].
Codeword 0
(0 . . . 15, . . . )
or BIT STRING
(SIZE (4))
>>Wideband CQI For
O
INTEGER
Cf. TS 36.213 [7.2.3].
Codeword 1
(0 . . . 15, . . . )
or BIT STRING
(SIZE (4))
>>Subband CQI For
0 . . .
0 indicates no subband
Codeword 0 List or
<maxCQISubbands >
CQI, which is always
Subband CQI List
chosen if associated
request does not want
subband CQI
>>>Subband CQI for
O
INTEGER
Cf. TS 36.213 [7.2.3].
codeword 0
(0 . . . 15, . . . )
or BIT STRING
(SIZE (2))
>>>Subband CQI for
O
INTEGER
Cf. TS 36.213 [7.2.3].
codeword 1
(0 . . . 15, . . . )
or BIT STRING
(SIZE (2))
>>UE-CSI process
M
INTEGER
CSI process
Configuration
(0 . . . 31)
configuration
information
or FFS
information.
Range bound
Explanation
maxUEsubsetCSIReport
Maximum UE subset size for which UE-CSI can be reported. The value is 32.
maxUE-CSIProcess
Maximum number of CSI processes per-UE. The value is 4.
maxCQISubbands
Maximum number of subbands for UE CQI reporting. The value is 28.
[0060] maxUEsubsetCSlReport can alternatively be set to 16, 20, 30, 35, or 40.
[0061] 9.2.x2 Enhanced Relative Narrowband Tx Power (E-RNTP)
[0062] This IE (infromation element) provides an indication on DL power restriction per PRB (physical resource block) per subframe in a cell and other information needed by to a neighbour eNB for interference aware scheduling.
[0000]
TABLE A5
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP Per
M
BIT STRING
Each position
—
—
PRB
(6 . . . 110, . . . )
in the bitmap
represents a
n PRB value
(i.e. first
bit = PRB 0
and so on),
for which the
bit value
represents
RNTP (n PRB ),
defined in TS
36.213 [11].
Value 0
indicates “Tx
not
exceeding
RNTP
threshold”.
Value 1
indicates “no
promise on
the Tx power
is given”.
This IE is
used to
indicate DL
power
restriction per
PRB for the
first
subframe. In
case the DL
power
restriction is
static, the
indicated DL
power
restriction is
maintained
over the
subsequent
subframes.
RNTP
M
ENUMERATED
RNTP threshold
—
—
Threshold
(−∞, −11,
is defined in
−10, −9, −8,
TS 36.213
−7, −6, −5, −4,
[11].
−3, −2, −1, 0,
1, 2, 3, . . . )
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . . )
antenna ports
Antenna
for
Ports
cell-specific
reference
signals)
defined in TS
36.211 [10]
P_B
M
INTEGER
P B is defined
—
—
(0 . . . 3, . . . )
in TS 36.213
[11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . . )
Predicted
Impact
Number Of
Occupied
PDCCH
OFDM
Symbols (see
TS 36.211
[10]).
Value 0
means “no
prediction is
available”.
Starting
M
INTEGER
Number of
SFN
(0 . . . 1023, . . . )
the first
system frame
from which
the RNTP
Per PRB Per
Subframe IE
is valid.
Starting
M
INTEGER
Index of the
Subframe
(0 . . . 9, . . . )
first subframe
Index
from which
the RNTP
Per PRB Per
Subframe IE
is valid.
RNTP List
O
2 . . . <maxnoofSubframes>
The first item
in the list
corresponds
to the second
subframe, the
second to the
third
subframe,
and so on.
The DL
power
restrictions
conveyed for
the first
subframe and
the ones
conveyed for
the
subsequent
subframes in
the list, are
together
applied
repeatedly.
>RNTP
M
BIT STRING
Each position
Per PRB
(6 . . . 110, . . . )
in the bitmap
Subframe-
represents a
Specific
n PRB value
(i.e. first
bit = PRB 0
and so on),
for which the
bit value
represents
RNTP (n PRB ),
defined in TS
36.213 [11].
Value 0
indicates “Tx
not
exceeding
RNTP
threshold”.
Value 1
indicates “no
promise on
the Tx power
is given”.
This IE is
used to
indicate DL
power
restriction per
PRB for the
corresponding
subframe.
Range bound
Explanation
maxSubframe
Maximum number of subframes. Value is 40.
Embodiment B
[0063] B1. Introduction
[0064] In the following we provide our views on CSI and eRNTP exchange, as well as proposals containing the required message structures.
[0065] B2. Discussion
[0066] B2.1 CSI Exchange: Configuring CSI Processes
[0067] The concept of CSI processes was defined in Rel.11 to enable CSI feedback from a UE to its serving eNB. The CSI feedback is determined for each CSI process according to the serving TP and interference hypothesis configured in that process. Each CSI process that is configured for a UE, comprises a set of resource elements on which non-zero power CSI-RSs are sent and a channel estimate is obtained by that UE using observations received on those resource elements.
[0068] In addition, a set of resource elements is also indicated by the CSI process (referred to as interference measurement resources (IMRs)) on which the UE estimates the covariance of the interference it observes. The channel and covariance estimates are together used by the UE to determine and send its feedback report corresponding to that CSI process. Multiple such CSI processes (up-to 4) can be configured for a UE, each process corresponding to a different choice of signal or interference hypothesis. Moreover, in the scenario in which fast switching of the serving TP is not possible, different CSI processes that are configured for any given UE typically correspond to different choices of interference hypothesis.
[0069] Note from the brief discussion above that in the event the interference hypothesis of a configured CSI process presumes muting from a TP (that is a dominant interferer for the UE of interest) which is controlled by the neighboring eNB, coordination among the eNBs is required in order to ensure that the interference estimated by the UE on the constituent IMRs is consistent with the assumed hypothesis. Another similar event that requires coordination is if the non-zero power CSI-RSs indicated in the CSI process must be interference protected in order to ensure reliable channel estimation at the UE. In both these events, the dominant interferer that is controlled by the neighboring eNB must be muted on certain resource elements. Thus, a mechanism (with appropriate signaling) should be available to share the CSI-RS (comprising non-zero power CSI-RSs and IMRs) configurations between eNBs, which would facilitate configuration of CSI processes across multiple eNBs.
[0070] Once the CSI processes are configured, the CSI exchanged among eNBs over the backhaul should include the respective CSI process configuration information, in order to convey the conditions under which the CSI was measured by the UE. This configuration information includes non-zero power CSI-RS information and IMR information (comprising the subframe indices and zero-power CSI-RS information). Since this configuration is anyway informed to the UE via RRC (or higher layer) signaling, the same information can be reused as a container to convey the configuration to the neighboring eNB.
[0071] Another way of conveying this configuration information is through a look-up-table. A look-up-table mapping an index to one or more distinct applied CSI process configurations can be constructed for each eNB. Here, by an applied CSI process we mean a process that is used by at-least one UE served by that eNB to measure its CSI. Such a table can be exchanged among neighbors first and from then on the configuration information can be exchanged via indices. The total number of configurations in the table can be limited in order to limit signaling overhead.
[0072] Suitable values for the number of configurations in this table are either 8 or 16 or 32.
[0073] B2.2 CSI Exchange: Contents
[0074] One eNB can send CSI report pertaining to one or more of UEs to a neighboring eNB. For each UE, the CSI that the eNB sends to a neighbor can comprise:
[0075] (i) CQI: up-to 2 CQIs, each including a wideband component and possible sub-band differential components
[0076] (ii) RI (rank indicator): one wideband component
[0077] We note that the PMI was excluded from the CSI exchange report [1]. The justification for this exclusion was to minimize the overhead and the fact that PMI can depend on fast changing channel information, thus reducing its utility over non ideal backhaul with a higher latency. However, in the absence of PMI the use of RI is limited. Indeed, any rank greater than 1 will convey only 2 CQI(s), one for each of the two codewords. No further information about the (average) spatial directions seen by that UE can be deduced by the eNB receiving the report. As a result, reporting the RI should be made optional. Moreover, the eNB requesting the CSI report should be able to specify whether or not it would like to receive RI reports. Similarly, the eNB requesting the CSI reports should be able to specify whether or not it requires subband specific CQI reports. This can be achieved by setting a bit (in the measurement request) to be 0 if rank is not requested and 1 otherwise. Another bit can be set to 0 if subband CQIs are not requested and 1 otherwise.
[0078] Processing (filtering or subsampling) of the short-term CSI (received via over-the-air signaling) at an eNB prior to exchange should be permitted.
[0079] One use case for this is when the periodicity of the CSI report that is requested by eNB1 to its neighbor eNB2, is larger than the over-the-air CSI signaling periodicity configured by eNB2. In this case eNB2 has to do some processing (such as subsampling or averaging) of the reports it receives before it sends it to eNB1. In this context, we note that the subsampling employed by eNB2 should be understood by eNB1 (if needed additional signaling can be added to ensure this). One possible way this can be accomplished (without any signaling overhead) is for eNB2 to use the subsampling factor determined by a pre-determined rule (known to or configured for all eNBs in advance) that outputs a subsampling factor, given the requested periodicity and CSI process configuration as inputs. On the other hand, averaging or scaling or filtering employed by eNB2 can be transparent to the receiving eNB1.
[0080] One of the goals of CSI exchange is to facilitate centralized RRM [3]. In a scenario with centralized RRM, the central node receiving the CSI reports should be able to keep track of the CSI information received for each particular UE, over all the received CSI reports. This can be achieved by including a UE identifier in each CSI report for each UE whose CSI is conveyed in that report. We want to include a unique ID (identification or identifier) for each user so that the receiving node knows which ones among all the reports that it receives, belong that user. This will be useful for RRM. Otherwise the receiving eNB will regard each received report as belonging to a distinct user. This can lead to sub-optimal resource allocation.
[0081] B2.3 eRNTP Exchange
[0082] Our view on eRNTP exchange is captured in a corresponding proposal attached in the end of this embodiment.
[0083] We note that the RNTP (i.e., downlink (DL) power restriction) for the first subframe is always conveyed. If no information about the DL power restriction on any subsequent subframe is conveyed, then the one conveyed for the first subframe can be assumed to remain static (i.e., applicable over subsequent subframes).
[0084] We also present several variations, one of which includes the use of multiple thresholds
[0085] B3. Conclusion
[0086] We discussed the necessary X2 message to support CSI and eRNTP exchange for inter-eNB CoMP and presented corresponding proposals.
[0087] Proposals
[0088] 9.1.2.11 Resource Status Request
[0089] This message is sent by an eNB 1 to a neighbouring eNB 2 to initiate the requested measurement according to the parameters given in the message.
[0090] Direction: eNB 1 →eNB 2 .
[0000]
TABLE B1
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
Message Type
M
9.2.13
YES
reject
eNB1
M
INTEGER
Allocated by
YES
reject
Measurement ID
(1 . . . 4095,
eNB 1
. . .)
eNB2
C-ifRegistrationRequestStop
INTEGER
Allocated by
YES
ignore
Measurement ID
(1 . . . 4095,
eNB 2
. . .)
Registration
M
ENUMERATED
A value set to
YES
reject
Request
(start, stop,
“stop”,
. . .)
indicates a
request to
stop all cells
measurements.
Report
O
BITSTRING
Each position
YES
reject
Characteristics
(SIZE(32))
in the bitmap
indicates
measurement
object the
eNB 2 is
requested to
report.
First Bit =
PRB
Periodic,
Second Bit =
TNL load Ind
Periodic,
Third Bit =
HW Load Ind
Periodic,
Fourth Bit =
Composite
Available
Capacity
Periodic, this
bit should be
set to 1 if at
least one of
the First,
Second or
Third bits is
set to 1,
Fifth Bit =
ABS Status
Periodic, Xth
Bit = UE-CSI
Periodic.
Other bits
shall be
ignored by
the eNB 2 .
Cell To Report
1
Cell ID list for
YES
ignore
which
measurement
is needed
>Cell To
1 . . .
EACH
ignore
Report Item
<maxCellineNB>
>>Cell ID
M
ECGI
—
—
9.2.14
Reporting
O
ENUMERATED
YES
ignore
Periodicity
(1000 ms, 2000 ms,
5000 ms, 10000 ms,
. . .)
Partial Success
O
ENUMERATED
Included if
YES
ignore
Indicator
(partial success
partial
allowed, . . .)
success is
allowed
CSI
O
BITSTRING
Each position
YES
ignore
Measurement
(SIZE(2))
in the bitmap
Report type
indicates the
type of CSI
measurement
to report.
First
bit = Rank,
Second
bit = subband
CQI.
((Reporting
O
ENUMERATED
Periodicity
YES
ignore
Periodicity of CSI
(5 ms, 10 ms,
for CSI
Measurement
20 ms, 40 ms,
Measurement
Report
80 ms, aperiodic,
Report
. . .)
Periodic
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value is
256.
Condition
Explanation
ifRegistrationRequestStop
This IE shall be present if the Registration Request IE is
set to the value “stop”.
[0091] 9.1.2.14 Resource Status Update
[0092] This message is sent by eNB2 to neighbouring eNB1 to report the results of the requested measurements.
[0093] Direction: eNB 2 →eNB 1 .
[0000]
TABLE B2
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
Message Type
M
9.2.13
YES
ignore
eNB1
M
INTEGER
Allocated by
YES
reject
Measurement ID
(1 . . . 4095, . . .)
eNB 1
eNB2
M
INTEGER
Allocated by
YES
reject
Measurement ID
(1 . . . 4095, . . .)
eNB 2
Cell
1
YES
ignore
Measurement
Result
>Cell
1 . . .
EACH
ignore
Measurement
<maxCellineNB>
Result Item
>>Cell ID
M
ECGI
9.2.14
>>Hardware
O
9.2.34
Load Indicator
>>S1 TNL
O
9.2.35
Load Indicator
>>Radio
O
9.2.37
Resource
Status
>>Composite
O
9.2.44
YES
ignore
Available
Capacity Group
>>ABS Status
O
9.2.58
YES
ignore
>> UE-CSI
O
9.2.x1
YES
ignore
Report
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value
is 256.
[0094] 9.2.x1 UE-CSI Report
[0095] This IE provides UE-CSI information for a set of UEs served by eNB 2 .
[0000]
TABLE B3
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
UE subset CSI Report
1 . . .
<maxUEsubsetCSIReport>
>(C-RNTI) UE ID
M
BIT STRING
ID of the UE served by
(SIZE (16))
the cell in eNB 2 .
Defined in TS 36.331.
>UE-CSI process
1 . . .
information
<maxUE-CSIprocess>
>>Rank Indicator
O
BIT STRING
The rank indicator IE is
(SIZE (3))
present only if it is
requested in the
associated request. In
that case Cf. TS 36.213
[7.2.3].
>>Wideband
M
BIT STRING
Cf. TS 36.213 [7.2.3].
CQI For
(SIZE (4))
Codeword 0
>>Wideband
O
BIT STRING
Cf. TS 36.213 [7.2.3].
CQI For
(SIZE (4))
Codeword 1
>>Subband CQI
0 . . .
0 indicates no subband
List
<maxCQISubbands >
CQI, which is always
chosen if associated
request does not want
subband CQI, or this IE
is present only if
associated request
wants subband CQI
>>>Subband
O
BIT STRING
Cf. TS 36.213 [7.2.3].
CQI for
(SIZE (2))
codeword 0
>>>Subband
O
BIT STRING
Cf. TS 36.213 [7.2.3].
CQI for
(SIZE (2))
codeword 1
>>UE-CSI
M
FFS
CSI process
process
configuration
Configuration
information.
information
Range bound
Explanation
maxUEsubsetCSIReport
Maximum UE subset size for which UE-CSI can be reported. The value is 32.
maxUE-CSIProcess
Maximum number of CSI processes per-UE. The value is 4.
maxCQISubbands
Maximum number of subbands for UE CQI reporting. The value is 28.
[0096] Alternatively, the parameter maxUEsubsetCSlReport can be 8, 16, 32, 48, 64, or 256. Further, optionally, the UE-ID can have a more compact representation using say 8 bits or 6 bits or 5 bits (equivalently 256 or 64 or 32 possible indices from a configurable table).
[0097] Next, we consider the case when subband indices have to be indicated. This is important to accommodate feedback modes that involve UE selected subband feedback.
[0000]
TABLE B4
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
UE subset CSI Report
1 . . .
<maxUEsubsetCSIReport>
>C-RNTI
M
BIT STRING
ID of the UE served by
(SIZE (16))
the cell in eNB 2 .
Defined in TS 36.331.
>UE-CSI process
1 . . .
information
<maxUE-CSIprocess>
>>Rank Indicator
O
BIT STRING
The rank indicator IE is
(SIZE (3))
present only if it is
requested in the
associated request. In
that case Cf. TS
36.213 [7.2.3].
>>Wideband CQI For
M
BIT STRING
Codeword 0
(SIZE (4))
>>Wideband CQI For
O
BIT STRING
Codeword 1
(SIZE (4))
>>Subband CQI List
0 . . .
This IE is present only
<maxCQISubbands>
if associated request
wants subband CQI
>>>Subband CQI
O
BIT STRING
for codeword 0
(SIZE (4))
>>>Subband CQI
O
BIT STRING
for codeword 1
(SIZE (4))
>>>Subband index
O
INTEGER
Included in case of UE
(0 . . . 27, . . . )
selected subband CQI
reporting.
>>UE-CSI process
M
FFS
CSI process
Configuration
configuration
information
information.
[0098] Note that as an alternative in the above tables, for each CQI the bit string field of 4 bits (2 bits) can be replaced by INTEGER (0..15, . . . ) (INTEGER (0..7, . . . )).
[0099] In another alternative the sub band indices can be conveyed by means of a combinatorial index which is described next.
[0100] The idea here is that depending on the number of PRBs (or RBs (resource blocks) for short) in the downlink available at sending eNB2 (a parameter which is known or conveyed separately to the receiving eNB1), the set of all possible subband selections that can be made together with the subband size, for all feedback modes, can be deduced by eNB1.
[0101] For example when 110 RBs are available at eNB2 (and this number is conveyed to eNB1) eNB1 can deduce that for a UE configured under:
[0102] Aperiodic, Mode 2-*: 6 UE selected subband indices
[0103] A subframe is composed of 28 subbands. Among 28 subbands, 6 subbands are selected by the UE. The number of PRBs in the subbands is 4 except for the last one; the number of PRBs in the last subband is 2 (4*27+2=110).
[0104] For Aperiodic, Mode 3-*: 14 higher layer-configured sub bands
[0105] A subframe is composed of 14 subbands. The number of PRBs in the subband is 8 except for the last one; the number of PRBs in the last subband is 6 (8*13+6=110).
[0106] For Periodic, Mode 2-*: 4 UE selected subband indices (with an additional constraint on choosing one sub band per bandwidth portion or part)
[0107] A subframe is composed of 14 subbands. Among 14 subbands, 4 subbands are selected by the UE. The number of PRBs in the subbands is 8 except for the last one; the number of PRBs in the last subband is 6 (8*13+6=110).
[0108] Then, considering all possible feasible subband selections under all the aforementioned feedback modes, it is possible to assign a unique label to each distinct feasible selection of sub bands. All possible such labels together decide the range of a combinatorial index R. As a result, knowing the value of R the receiving eNB1 can deduce the subband selection. The associated CQIs (one for each subband in the indicated selection) can be ordered in the increasing order of the frequency range represented by the indicated subbands. Each such CQI can be conveyed using full representation (i.e., using 16 possibilities) which can then be directly used by the receiving eNB1.
[0000]
TABLE B5
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
UE subset CSI Report
1 . . .
<maxUEsubsetCSIReport>
>C-RNTI
M
BIT STRING
ID of the UE
(SIZE (16))
served by the cell
in eNB 2 .
Defined in TS
36.331.
>UE-CSI process
1 . . .
information
<maxUE-CSIprocess>
>>Rank Indicator
O
BIT STRING
The rank indicator
(SIZE (3))
IE is present only if
it is requested in
the associated
request. In that
case Cf. TS 36.213
[7.2.3].
>>Wideband CQI For
M
BIT STRING
Codeword 0
(SIZE (4))
>>Wideband CQI For
O
BIT STRING
Codeword 1
(SIZE (4))
>> combinatorial
O
Integer FFS
This IE is present
index
only if associated
request wants
subband CQI
>>>Subband CQI List
0 . . .
The number of
<maxCQISubbands >
subbands in the list
as well as their
respective indices
and sizes are
deduced from the
combinatorial index.
>>>>Subband CQI
M
BIT STRING
for codeword 0
(SIZE (4))
>>>>Subband CQI
O
BIT STRING
for codeword 1
(SIZE (4))
>>UE-CSI process
M
FFS
CSI process
Configuration
configuration
information
information.
[0109] UE Configuration Independent Coding Structure
[0110] A coding structure for signaling CSI over X2 in a UE-configuration independent way is shown in Table I1. In this structure, a subband is defined as a set of contiguous PRBs having the same CQI value. The subband partitioning is left to the sending eNB2 implementation, and is not restricted by the UE's CSI reporting configuration. Each indicated CQI follows the definition of a 4 bit CQI (Cf. TS 36.213). This allows for the sending eNB2 to process the CSI it receives from the UE in any manner as long as each indicated CQI is consistent with the basic CQI definition. The receiving eNB1 can directly use these CQIs while being agnostic to how they were procured and processed by eNB1.
[0000]
TABLE B6
UE configuration independent coding structure
IE type and
IE/Group Name
Presence
Range
reference
Semantics description
CSI per UE
1 . . .
<maxnoofUE-CSI>
>C-RNTI
M
BIT STRING
(SIZE (16))
>CSI per Interference
1 . . .
Hypotheses
<maxnoofInterferenceHypothesis >
>>Interference Hypothesis
M
[FFS]
Information
>>Wideband CQI for
M
INTEGER
Codeword 0
(0 . . . 15, . . . )
>>Wideband CQI for
O
INTEGER
Codeword 1
(0 . . . 15, . . . )
>>Rank Indication
M
INTEGER
Defined in TS 36.213 [11].
(1 . . . 8, . . . )
>>Subband CQI List
0 . . .
Subbands are listed in the
<maxnoofSubband>
order of increasing
frequency.
>>>Subband Start
O
INTEGER
PRB number of the first
(0 . . . 109, . . . )
PRB in the subband. If this
IE is not present, the
subband is contiguous with
the previous subband in the
list, or starts with PRB 0 if
this is the first subband in
the list.
>>>Subband Size
O
INTEGER
Number of contiguous
(1 . . . 110, . . . )
PRBs in the subband. If this
IE is not present, the value
is the same as the previous
subband in the list.
>>>Subband CQI for
M
INTEGER
Codeword 0
(0 . . . 15, . . . )
>>>Subband CQI for
O
INTEGER
Codeword 1
(0 . . . 15, . . . )
Range bound
Explanation
maxnoofUE-CSI
Maximum number of UE-specific CSI reports. Value is 128 or 64 or 32
maxnoofInterferenceHypotheses
Maximum number of Interference Hypotheses. Value is 4.
maxnoofSubband
Maximum number of Subbands. Value is 28.
[0111] We note here that reporting full (complete) CQI (with 16 possibilities) for each indicated subband CQI instead of differential CQI is useful since otherwise the receiving eNB1 may not know how to combine a corresponding wideband CQI and differential sub-band CQI (with fewer than 16 possibilities) in order to obtain the full CQI for that subband, for instance, in the case that the precise feedback mode configured for the UE of interest under that CSI process is not conveyed to the receiving eNB1. We note here also that it might be desirable to not impose restrictions on sending eNB2 on how it combines reports from multiple different feedback modes configured for that UE under the same CSI process. Then, note that when aperiodic feedback mode 3-1 is configured for the UE (by eNB2), the UE reported sub band CQI is encoded differentially with respect to the corresponding wideband CQI using 2 bits representing differential values {-2, 0, 1, 2}. On the other hand, in the case of aperiodic feedback mode 2-0 or 2-2, only the best M-average is reported by the UE by differentially encoding it with respect to a corresponding wideband CQI using 2 bits representing differential values {1, 2, 3, 4}. Further, in case of periodic feedback mode 2-1 the CQI corresponding to codeword-1 for each UE selected subband within a bandwidth part can itself be of 4 bits, whereas that of codeword-2 (when RI>1) is differentially encoded with respect to CQI of codeword-1 using 3 bits.
[0112] It becomes apparent from the above discussion that a transparent way of conveying CQI (without having to convey all details regarding to one or more feedback modes configured under that CSI process for that UE) is to allow for full (complete) CQI for each indicated subband.
[0113] Another issue that is important, is to ensure that the RI and CQIs conveyed by eNB2 to eNB1 in a UE CSI report are mutually consistent, i.e., all the reported CQIs are computed by the UE for the same RI (which is identical to the one in the Rank Indication IE when the latter is present). This issue is important to address because under certain feedback modes (such as periodic mode 2-1) the RI and the wideband CQI(s) as well as the subband CQI(s) for one or more bandwidth portions can be reported by the UE on different subframes. Thus, depending on the periodicity defined by eNB1 in its CSI request, it can happen that the latest RI available for the UE under the CSI process, can be different from the one for which the most recent CQI(s) are computed. In such a case, the sending eNB2 should ensure that its CSI report is consistent, for instance by using the RI value for which the most recently available CQI(s) have been computed.
[0114] The variation (which allows the requesting eNB to specify whether or not it wants to receive subband CQI(s) or Rank Indication is provided below. In this context, we note that since the requesting eNB1 has no control over how eNB2 configures CSI processes (and constituent feedback modes) for its users, it should be in any case able to exploit different type of CSI reports (wideband only or wideband and subband).
[0000]
TABLE B7
IE type and
IE/Group Name
Presence
Range
reference
Semantics description
CSI per UE
1 . . . <maxnoofUE-CSI>
>C-RNTI
M
BIT STRING
(SIZE (16))
>CSI per Interference
1 . . . <maxnoofInterferenceHypothesis >
Hypotheses
>>Interference
M
[FFS]
Hypothesis Information
>>Wideband CQI for
M
INTEGER(0 . . . 15, . . . )
Codeword 0
>>Wideband CQI for
O
INTEGER(0 . . . 15, . . . )
Codeword 1
>>Rank Indication
O
INTEGER(1 . . . 8, . . . )
The rank indication IE is
present only if it is
requested in the
associated request. In
that case it follows the
definition in TS 36.213
[11].
>>Subband CQI List
0 . . .<maxnoofSubband>
This IE is present only if
associated request
wants subband CQI. In
that case subbands are
listed in the order of
increasing frequency.
>>>Subband Start
O
INTEGER(0 . . . 109, . . . )
PRB number of the first
PRB in the subband. If
this IE is not present,
the subband is
contiguous with the
previous subband in the
list, or starts with PRB 0
if this is the first
subband in the list.
>>>Subband Size
O
INTEGER(1 . . . 110, . . . )
Number of contiguous
PRBs in the subband. If
this IE is not present,
the value is the same as
the previous subband in
the list.
>>>Subband CQI for
M
INTEGER(0 . . . 15, . . . )
Codeword 0
>>>Subband CQI for
O
INTEGER(0 . . . 15, . . . )
Codeword 1
[0115] Another variation which allows for further simplification at the expense of not being bit efficient is as follows. Here the full CQIs for all possible subbands (which can be determined by the number of PRBs in the downlink available at eNB2) are always conveyed for a UE under the CSI process. In case the sub band CQI is not reported by a UE under the configured feedback mode for a subband, the sending eNB2 simply uses the corresponding wideband CQI value for that subband. Then, note that there is no need to include the wideband CQI(s) in case the associated request wants subband CQI.
[0116] 9.2.19 Relative Narrowband Tx Power (RNTP)
[0117] This IE provides an indication on DL power restriction per PRB in a cell and other information needed by a neighbour eNB for interference aware scheduling.
[0000]
TABLE B8
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP Per
M
BIT
Each position in
—
—
PRB
STRING
the bitmap
(6 . . . 110,
represents a n PRB
. . .)
value (i.e. first
bit = PRB 0 and so
on), for which the
bit value
represents RNTP
(n PRB ), defined in
TS 36.213 [11].
Value 0 indicates
“Tx not exceeding
RNTP threshold”.
Value 1 indicates
“no promise on the
Tx power is
given”.
This IE is used to
indicate DL power
restriction per
PRB for the first
subframe. In case
the DL power
restriction is static,
the indicated DL
power restriction
is maintained over
the subsequent
subframes.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞,
defined in TS
−11, −10,
36.213 [11].
−9, −8, −7,
−6, −5, −4,
−3, −2, −1,
0, 1, 2, 3,
. . .)
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . .)
antenna ports for
Antenna
cell-specific
Ports
reference signals)
defined in TS
36.211 [10]
P_B
M
INTEGER
P B is defined in TS
—
—
(0 . . . 3, . . .)
36.213 [11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . .)
Predicted Number
Impact
Of Occupied
PDCCH OFDM
Symbols (see TS
36.211 [10]).
Value 0 means
“no prediction is
available”.
Extended
M or O
BIT
Each position in
RNTP Per
STRING
the bitmap
PRB
(6 . . . 4290,
represents a PRB
. . .)
in a subframe, for
which value “1”
indicates
‘interference
protected
resource’ or ‘no
promise on the Tx
power is given’
and value “0”
indicates
‘resource with no
utilization
constraints’ or ‘Tx
not exceeding
RNTP threshold.’
The first bit
corresponds to
PRB 0 of the
second or first
subframe for
which the
extended RNTP
per PRB IE is
valid, the second
bit corresponds to
PRB 1 of the
second or first
subframe for
which the
extended RNTP
per PRB IE is
valid, and so on.
The length of the
bit string is an
integer (maximum
39) multiple of
N RB DL . N RB DL is
defined in TS
36.211 [10].
The bit string may
span across
multiple
contiguous
subframes.
The pattern
across contiguous
subframes
(formed by RNTP
per PRB and
extended RNTP
per PRB) is
continuously
repeated.
RNTP per
0 . . . 1
PRB start
time
>Starting
M or O
INTEGER
Number of the first
SFN
(0 . . . 1023,
system frame from
. . .)
which the RNTP Per
PRB (Per Subframe)
IE is valid or SFN
of the radio frame
containing the first
subframe when the
RNTP Per PRB IE is
valid.
>Starting
M or O
INTEGER
Index of the first
Subframe
(0 . . . 9,
subframe from
Index
. . .)
which the RNTP Per
PRB (Per Subframe)
IE is valid or
Subframe number,
within the radio
frame indicated by
the Start SFN IE, of
the first subframe
when the RNTP Per
PRB IE is valid.
[0118] An alternate Table for RNTP enhancement is given below.
[0000]
TABLE B9
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP per
M
BIT
Each position in
—
—
PRB
STRING
the bitmap
(6 . . . 110,
represents a n PRB
. . .)
value (i.e. first
bit = PRB 0 and so
on), for which the
bit value
represents RNTP
(n PRB ), defined in
TS 36.213 [11].
Value 0 indicates
“Tx not exceeding
RNTP threshold”.
Value 1 indicates
“no promise on the
Tx power is
given”.
This IE is ignored
if the RNTP per
PRB per subframe
IE is present.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞, −11,
defined in TS
−10, −9,
36.213 [11].
−8, −7, −6,
−5, −4, −3,
−2, −1, 0,
1, 2, 3,
. . .)
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . .)
antenna ports for
Antenna
cell-specific
Ports
reference signals)
defined in TS
36.211 [10]
P_B
M
INTEGER
P B is defined in TS
—
—
(0 . . . 3,
36.213 [11].
. . .)
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4,
Predicted Number
Impact
. . .)
Of Occupied
PDCCH OFDM
Symbols (see TS
36.211 [10]).
Value 0 means
“no prediction is
available”.
RNTP Per
O
BIT
Each position in
PRB per
STRING
the bitmap
subframe
(6 . . . 4400,
represents a PRB
. . .)
in a subframe, for
which value “1”
indicates ‘no
promise on the Tx
power is given’
and value “0”
indicates ‘Tx not
exceeding RNTP
threshold.’
The first bit
corresponds to
PRB 0 of the first
subframe for
which the RNTP
per PRB per
subframe IE is
valid, the second
bit corresponds to
PRB 1 of the first
subframe for
which the RNTP
per PRB per
subframe IE is
valid, and so on.
The length of the
bit string is an
integer (maximum
40) multiple of
N RB DL . N RB DL is
defined in TS
36.211 [10].
The bit string may
span across
multiple
contiguous
subframes.
The pattern
across contiguous
subframes formed
by RNTP per PRB
per subframe IE is
continuously
repeated.
RNTP per
0 . . . 1
PRB per
subframe
start time
>Starting
M
INTEGER
SFN of the radio
SFN
(0 . . . 1023,
frame containing the
. . .)
first subframe when
the RNTP Per PRB
Per Subframe IE is
INTEGER
valid.
>Starting
M
(0 . . . 9,
Subframe number,
Subframe
. . .)
within the radio
Index
frame indicated by
the Start SFN IE, of
the first subframe
when the RNTP Per
PRB Per Subframe
IE is valid.
[0119] Another alternate Table for RNTP enhancement is given below.
[0000]
TABLE B10
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP per
M
BIT
Each position in
—
—
PRB
STRING
the bitmap
(6 . . . 110,
represents a n PRB
. . .)
value (i.e. first
bit = PRB 0 and so
on), for which the
bit value
represents RNTP
(n PRB ), defined in
TS 36.213 [11].
Value 0 indicates
“Tx not exceeding
RNTP threshold”.
Value 1 indicates
“no promise on the
Tx power is
given”.
This IE is ignored
if the RNTP per
PRB per subframe
IE is present.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞, −11,
defined in TS
−10, −9,
36.213 [11].
−8, −7, −6,
−5, −4, −3,
−2, −1, 0,
1, 2, 3,
. . .)
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4,
antenna ports for
Antenna
. . .)
cell-specific
Ports
reference signals)
defined in TS
36.211 [10]
P_B
M
INTEGER
P B is defined in TS
—
—
(0 . . . 3,
36.213 [11].
. . .)
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4,
Predicted Number
Impact
. . .)
Of Occupied
PDCCH OFDM
Symbols (see TS
36.211 [10]).
Value 0 means
“no prediction is
available”.
RNTP Per
O
BIT
Each position in
PRB per
STRING
the bitmap
subframe
(6 . . . 4400,
represents a PRB
. . .)
in a subframe, for
which value “1”
indicates ‘resource
with no utilization
constraints’ and
value “0” indicates
‘interference
protected resource.’
The first bit
corresponds to
PRB 0 of the first
subframe for
which the RNTP
per PRB per
subframe IE is
valid, the second
bit corresponds to
PRB 1 of the first
subframe for
which the RNTP
per PRB per
subframe IE is
valid, and so on.
The length of the
bit string is an
integer (maximum
40) multiple of
N RB DL . N RB DL is
defined in TS
36.211 [10].
The bit string may
span across
multiple
contiguous
subframes.
The pattern
across contiguous
subframes formed
by RNTP per PRB
per subframe IE is
continuously
repeated.
RNTP per
0 . . . 1
PRB per
subframe
start time
>Starting
M
INTEGER
SFN of the radio
SFN
(0 . . . 1023,
frame containing the
. . .)
first subframe when
the RNTP Per PRB
Per Subframe IE is
valid.
>Starting
M
INTEGER
Subframe number,
Subframe
(0 . . .9,
within the radio
Index
. . .)
frame indicated by
the Start SFN IE, of
the first subframe
when the RNTP Per
PRB Per Subframe
IE is valid.
[0120] Another alternative using multiple thresholds conveyed via 2 bits is given below.
[0000]
TABLE B11
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
ERNTP Per
M
BIT
Each position in
—
—
PRB and
STRING
the bitmap
subframe
(12 . . . 220,
represents a PRB
. . .)
in a subframe, for
which the value
“xx” indicates how
the transmission
power in a
resource block is
mapped relative to
the two power
thresholds:
00 - power level
not exceeding the
LPTH
01 - power level
between LPTH
and MPTH;
10 - power level
between MPTH
and HPTH;
11 - no promise
on the Tx power is
given.
The first 2 bits
correspond to
PRB 0 of the first
subframe for
which the IE is
valid, the following
2 bits correspond
to PRB 1 of the
first subframe for
which the IE is
valid, and so on.
The bit string may
span across
multiple
contiguous
subframes.
The length of the
bit string is an
integer (maximum
40) multiple of
N RB DL . The
parameter is
defined in TS
36.211 [10].
The ERNTP
pattern is
continuously
repeated with a
periodicity
indicated in
Periodicity.
Transmitted
power levels
LPTH (Low
M
ENUMERATED
Lower RNTP
—
—
Power
(−∞, −11,
power threshold,
Threshold)
−10, −9,
using the
−8, −7, −6,
RNTP threshold
−5, −4, −3,
defined in TS
−2, −1, 0,
36.213 [11].
1, 2, 3,
. . .)
MPTH
M
ENUMERATED
Medium RNTP
(Medium
(−∞, −11,
power threshold,
Power
−10, −9,
using the
Threshold)
−8, −7, −6,
RNTP threshold
−5, −4, −3,
defined in TS
−2, −1, 0,
36.213 [11].
1, 2, 3,
. . .)
HPTH (High
M
ENUMERATED
Higher RNTP
Power
(−∞, −11,
power threshold,
Threshold)
−10, −9,
using the
−8, −7, −6,
RNTP threshold
−5, −4, −3,
defined in TS
−2, −1, 0,
36.213 [11].
1, 2, 3,
. . .)
Subframe
sequence
definition
>Start SFN
M
INTEGER
SFN of the radio
(0 . . . 1023)
frame containing
the first subframe
where the RNTP
Per PRB Per
Subframe IE is
valid.
>Start
M
INTEGER
Subframe
Subframe
(0 . . . 39)
number, within the
Number
radio frame
indicated by the
Start SFN IE, of
the first subframe
when the RNTP
Per PRB Per
Subframe IE is
valid.
No. of
M
1 . . . 40
No. of subframes
subframes
for which is
defined the
bitstream
Periodicity
1 . . . 40
The number of
subframes after
which the bit
pattern is
repeated
Number Of
M
ENUMERATED
P (number of
Cell-specific
(1, 2, 4,
antenna ports for
Antenna
. . .)
cell-specific
Ports
reference signals)
defined in TS
36.211 [10]
P_B
M
INTEGER
P B is defined in
(0 . . . 3,
TS 36.213 [11].
. . .)
[0121] The point in the table given above is that since the choice ‘11’ already indicates no promise on the power level (which covers the case of transmit power being arbitrarily high) we can use three thresholds (instead of two) since there is no need to convey that the power level is greater than HPTH (as this is subsumed by ‘11’).
[0122] However, one problem with indicating multiple thresholds is that the current CoMP hypothesis (implicitly) assumes just one threshold. In this sense there is a mismatch between using multiple thresholds in eRNTP and not in the CoMP hypothesis. Consequently, the full potential of multiple thresholds may not be realized inspire of the additional overhead.
Embodiment C
[0123] C1. Introduction
[0124] In the following we provide our views on CSI exchange, as well as proposals containing the required message structures.
[0125] C2. Discussion
[0126] C2.1 CSI Exchange: Configuring CSI Processes
[0127] From previous discussion it is evident that coordination among the eNBs is required in order to define a set of assignable CSI processes that have a consistent meaning Once the set of these CSI processes is defined, the CSI exchanged among eNBs should include the respective CSI process configuration information, in order to convey the conditions under which the CSI was measured by the UE. This configuration information should include CSI-RS-ConfigNZP [36.331 b, Section 6.3.2] and CSI-IM-Config [36.331 b, Section 6.3.2]. We note here that doing so would enable exchange of per-point CSI process (under which the UE estimates RS from any one point in its measurement set (or CoMP set) while the associated IMR measures the out of CoMP set or out of cluster interference) configuration. If one such process is sent to a receiving eNB for each point in that UE's measurement set, any interference hypothesis for that UE can be emulated by receiving eNB. This can indeed mitigate the bottleneck in terms defining enough CSI processes to cover sufficiently many interference hypotheses. One way of conveying this configuration information is through a look-up-table. A look-up-table mapping an index to each possible distinct CSI process configuration can be constructed (possibly separately for each eNB). Here, by a possible CSI process we mean a process that can be assigned to a served UE to measure its CSI. Such a table can be exchanged among neighbors first and from then on the configuration information can be exchanged via indices. The total number of defined processes (including their configuration information) in each table can be limited in order to limit signaling overhead. For instance, this number could be one of {7,8, 9,16,32}. As an option, the configuration information for a process can also include power offset value Pc and/or offsets Pa and Pb, that were configured for that process. Further optionally, it can also indicate for which (if any) among the other processes, that process was set to be reference rank process. As an additional option, the configured feedback mode information (such as periodic or aperiodic) can also be included.
[0128] C2.2 CSI Exchange: Contents
[0129] One eNB can send CSI reports pertaining to one or more of its UEs to a neighboring eNB. For each UE, the CSI that the eNB sends to a neighbor can comprise:
[0130] CQI: up-to 2 CQIs, each including a wideband component and possible sub-band components
[0131] RI: one wideband component
[0132] We note that the PMI was excluded from the CSI exchange report [1]. The justification for this exclusion was to minimize the overhead and the fact that PMI can depend on fast changing channel information, thus reducing its utility over non ideal backhaul with a higher latency. However, in the absence of PMI the use of RI is limited. Indeed, any rank greater than 1 will convey only 2 CQI(s), one for each of the two codewords. No further information about the (average) spatial directions seen by that UE can be deduced by the eNB receiving the report. As a result, reporting the RI should be made optional. Moreover, the eNB requesting the CSI report (eNB1) should be able to specify whether or not it would like to receive RI reports. Similarly, the eNB requesting the CSI reports should be able to specify whether or not it requires subband specific CQI reports. This can be achieved by setting a bit (in the measurement request) to be 0 if rank is not requested and 1 otherwise. Another bit can be set to 0 if subband CQIs are not requested and 1 otherwise. In this context, we note that since the requesting eNB has no control over how the sending eNB (eNB2) configures CSI processes (and constituent feedback modes) for its users, it should be in any case able to exploit different type of CSI reports (wideband only or wideband and subband).
[0133] Proposal: Include optional IE in resource status request indicating whether RI and/or subband CQI should be sent in the resource status response message.
[0134] Implementation based processing of the short-term CSI (received via over-the-air signaling) by the sending eNB, prior to CSI exchange has been agreed. In this context, we believe that reporting full (complete) CQI (with 16 possibilities), where each such CQI follows the definition of a 4 bit CQI (Cf. TS 36.213), for each indicated subband instead of differential CQI is useful. This has main two advantages. It allows the sending eNB full freedom in obtaining these CQIs. Indeed, it is desirable to not impose restrictions on sending eNB2 on how it processes or combines reports from multiple different feedback modes configured for a UE under the same CSI process. Secondly, the receiving eNB can be agnostic to the configured feedback modes. This latter point is important because when aperiodic feedback mode 3-1 is configured for the UE (by eNB2), the UE reported sub band CQI is encoded differentially with respect to the corresponding wideband CQI using 2 bits representing differential values {-2, 0,1,2}. On the other hand, in the case of aperiodic feedback mode 2-0 or 2-2, only the best M-average CQI is reported by the UE by differentially encoding it with respect to a corresponding wideband CQI, using 2 bits representing differential values {1,2,3,4}. Further, in case of periodic feedback mode 2-1 the CQI corresponding to codeword-1 for each UE selected subband within a bandwidth part can itself be of 4 bits, whereas that of codeword-2 (when RI>1) is differentially encoded with respect to CQI of codeword-1 using 3 bits.
[0135] It becomes apparent from the above discussion that a transparent way of conveying CQI (without having to convey all details regarding to one or more feedback modes configured under that CSI process for that UE) is to allow for full (complete) CQI for each indicated subband.
[0136] Proposal: Convey each subband CQI using full representation (4 bits or 16 possibilities)
[0137] Next, we consider subband indexing and propose an alternative in which the subband selection (including their sizes, indices) is conveyed by means of a combinatorial index which is described next.
[0138] This idea is a simple extension of that used in TS 36.213 for aperiodic feedback mode 2-*. In particular, depending on the number of PRBs (or RBs for short) in the downlink available at sending eNB2 (a parameter which is known or conveyed separately to the receiving eNB1), the set of all possible subband selections that can be made together with the subband sizes for all feedback modes can be deduced by eNB1.
[0139] For example when 110 RBs are available at eNB2 (and this number is conveyed to eNB1) eNB1 can deduce that for a UE configured under:
[0140] Aperiodic, Mode 2-*: 6 UE selected subband indices
[0141] A subframe is composed of 28 subbands. Among 28 subbands, 6 subbands are selected by the UE. The number of PRBs in the subbands is 4 except for the last one; the number of PRBs in the last subband is 2 (4*27+2=110).
[0142] For Aperiodic, Mode 3-*: 14 higher layer-configured sub bands
[0143] A subframe is composed of 14 subbands. The number of PRBs in the subband is 8 except for the last one; the number of PRBs in the last subband is 6 (8*13+6=110).
[0144] For Periodic, Mode 2-*: 4 UE selected subband indices (with an additional constraint on choosing one sub band per bandwidth portion or part)
[0145] A subframe is composed of 14 subbands. Among 14 subbands, 4 subbands are selected by the UE. The number of PRBs in the subbands is 8 except for the last one; the number of PRBs in the last subband is 6 (8*13+6=110).
[0146] Then, considering all possible feasible subband selections under all the aforementioned feedback modes, it is possible to assign a unique label to each distinct feasible selection of sub bands. All possible such labels together decide the range of a combinatorial index R. As a result, knowing the value of R the receiving eNB can deduce the subband selection. The associated CQIs (one for each subband in the indicated selection) can be ordered in the increasing order of the frequency range represented by the indicated subbands. Each such CQI can be conveyed using full representation (i.e., using 16 possibilities) which can then be directly used by the receiving eNB1.
[0147] Proposal: Convey subband indexing and size information via a combinatorial index.
[0148] Another issue that is important, is to ensure that the RI and CQIs conveyed by eNB2 to eNB1 in a UE CSI report are mutually consistent, i.e., all the reported CQIs are computed by the UE for the same RI (which is identical to the one in the Rank Indication IE when the latter is present). This issue is important to address because under certain feedback modes (such as periodic mode 2-1) the RI and the wideband CQI(s) as well as the subband CQI(s) for one or more bandwidth portions can be reported by the UE on different subframes. Thus, depending on the periodicity defined by eNB1 in its CSI request, it can happen that the latest RI available for the UE under the CSI process, can be different from the one for which one or more of the most recently available CQI(s) are computed. In such a case, the sending eNB2 should ensure that its CSI report is consistent, for instance by using the RI value for which the most recently available CQI(s) have been computed.
[0149] Proposal: Sending eNB must ensure RI and CQI(s) conveyed in a CSI report are mutually consistent.
[0150] One of the goals of CSI exchange is to facilitate centralized RRM. In a scenario with centralized RRM, the central node receiving the CSI reports should be able to keep track of the CSI information received for each particular UE, over all the received CSI reports. In order to ensure this, it has been agreed that a UE identifier will be included in each CSI report for each UE whose CSI is conveyed in that report. This ID should enable the receiving node to deduce which ones among all the reports that it receives, belongs to that user, thereby facilitating RRM. Including a similar UE ID in the reference signal received power (RSRP) reports will also be beneficial and allow the receiving eNB to combine or jointly exploit these two sets of reports.
[0151] Proposal: Include UE ID in RSRP measurement report
[0152] Proposals:
[0153] 9.1.2.11 Resource Status Request
[0154] This message is sent by an eNB 1 to a neighbouring eNB 2 to initiate the requested measurement according to the parameters given in the message.
[0155] Direction: eNB 1 →eNB 2 .
[0000]
TABLE C1
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
Message
M
9.2.13
YES
reject
Type
eNB1
M
INTEGER
Allocated by
YES
reject
Measurement
(1 . . . 4095, . . .)
eNB 1
ID
eNB2
C-ifRegistrationRequest
INTEGER
Allocated by
YES
ignore
Measurement
Stop
(1 . . . 4095, . . .)
eNB 2
ID
Registration
M
ENUMERATED
A value set to
YES
reject
Request
(start, stop,
“stop”,
. . .)
indicates a
request to
stop all cells
measurements.
Report
O
BITSTRING
Each position
YES
reject
Characteristics
(SIZE(32))
in the bitmap
indicates
measurement
object the
eNB 2 is
requested to
report.
First Bit =
PRB Periodic,
Second Bit =
TNL load Ind
Periodic,
Third Bit =
HW Load Ind
Periodic,
Fourth Bit =
Composite
Available
Capacity
Periodic, this
bit should be
set to 1 if at
least one of
the First,
Second or
Third bits is
set to 1,
Fifth Bit =
ABS Status
Periodic, Xth
Bit = UE-CSI
Periodic.
Other bits
shall be
ignored by the
eNB 2 .
Cell To
1
Cell ID list for
YES
ignore
Report
which
measurement
is needed
>Cell To
1 . . .
EACH
ignore
Report Item
<maxCellineNB>
>>Cell ID
M
ECGI
—
—
9.2.14
Reporting
O
ENUMERATED
YES
ignore
Periodicity
(1000 ms, 2000 ms,
5000 ms, 10000 ms,
. . .)
Partial
O
ENUMERATED
Included if
YES
ignore
Success
(partial success
partial
Indicator
allowed, . . .)
success is
allowed
CSI
O
BITSTRING
Each position
YES
ignore
Measurement
(SIZE(2))
in the bitmap
Report type
indicates the
type of CSI
measurement
to report.
First
bit = Rank,
Second
bit = subband
CQI.
Reporting
O
ENUMERATED
Periodicity for
YES
ignore
Periodicity of
(5 ms, 10 ms,
CSI
CSI
20 ms, 40 ms,
Measurement
Measurement
80 ms, aperiodic,
Report
Report
. . .)
Periodic
Condition
Explanation
ifRegistrationRequestStop
This IE shall be present if the Registration Request IE is
set to the value “stop”.
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value
is 256.
[0156] 9.1.2.14 Resource Status Update
[0157] This message is sent by eNB 2 to neighbouring eNB 1 to report the results of the requested measurements.
[0158] Direction: eNB 2 →eNB 1 .
[0159] 9.2.aa UE-CSI Report
[0160] This IE provides UE-CSI information for a set of UEs served by eNB 2 .
[0000]
TABLE C2
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per UE
1 . . . <maxUEReport>
>UE ID
M
BIT STRING
ID of the UE
(SIZE (16))
served by the cell
in eNB 2 .
>CSI report per CSI
1 . . . <maxCSIprocess>
process
>>Rank Indicator
O
INTEGER
The rank indicator
(1 . . . 8, . . . )
IE is present only if
it is requested in
the associated
request. In that
case Cf. TS
36.213 [7.2.3].
>>Wideband CQI For
M
INTEGER
Codeword 0
(0 . . . 15, . . . )
>>Wideband CQI For
O
INTEGER
Codeword 1
(0 . . . 15, . . . )
>>combinatorial
O
Integer FFS
This IE is present
index
only if associated
request wants
subband CQI
>>>Subband CQI List
0 . . . <maxCQISubbands >
The number of
subbands in the list
as well as their
respective indices
and sizes are
deduced from the
combinatorial index.
Subband CQIs are
sorted in the order of
increasing
frequency.
>>>>Subband CQI
M
INTEGER
for codeword 0
(0 . . . 15, . . . )
>>>>Subband CQI
O
INTEGER
for codeword 1
(0 . . . 15, . . . )
>>UE-CSI process
M
FFS
CSI process
Configuration
configuration
information
information.
[0161] We now consider eRNTP exchange.
[0162] It has been agreed that eRNTP will be delivered with the Load Information message.
[0163] In the following, we provide our views on content of this message, as well as a proposal.
[0164] C3. Discussion
[0165] C3.1 eRNTP Exchange
[0166] One concern is that a receiving eNB does not have the means to differentiate the “meaning” of the CoMP hypothesis. In particular, a potential issue is that the signaled hypothesis could be a “suggestion” by the sender or an “action” which implies that the pattern in the hypothesis will be applied. A proposed solution to this issue is to introduce an indicator IE in the CoMP Information IE to convey that the constituent resource allocation is an action. This proposal can be useful if a common pre-configured threshold is used (or implicitly assumed) with or with our this indicator IE. In other words, the “suggestion for” as well as the “action” by an eNB (or cell) are based on a common threshold (pre-configured for that eNB or cell and known to its neighbors). Another slightly more preferable option is to enhance and use the existing RNTP in order to convey the “action”. The enhancements can be done in two ways. The contents are captured in two corresponding proposals attached in the sequel.
[0167] The first presented proposal is based on a single threshold and exploits that fact that the RNTP (i.e., downlink (DL) power restriction) for the first subframe (subframe #0) is always conveyed. Then, if no information about the DL power restriction on any subsequent subframe is conveyed, the one conveyed for the first subframe can be assumed to remain static (i.e., applicable over subsequent subframes).
[0168] The second proposal is based one multiple thresholds. The point here is that since the choice ‘11’ already indicates no promise on the power level (which covers the case of transmit power being arbitrarily high) we can use three thresholds (instead of two), since there is no need to convey that the power level is greater than HPTH (as this is subsumed by ‘11’)
[0169] Proposal:
[0170] 9.2.19 Relative Narrowband Tx Power (RNTP)
[0171] This IE provides an indication on DL power restriction per PRB in a cell and other information needed by a neighbour eNB for interference aware scheduling.
[0000]
TABLE C3
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP Per PRB
M
BIT STRING
Each position in
—
—
(6. . . 110, . . .)
the bitmap
represents a n PRB
value (i.e. first
bit = PRB 0 and so
on), for which the
bit value
represents RNTP
(n PRB ), defined in
TS 36.213 [11].
Value 0 indicates
“Tx not exceeding
RNTP threshold”.
Value 1 indicates
“no promise on the
Tx power is
given”. This IE is
used to indicate
DL power
restriction per PRB
for the first
subframe.
In case the DL
power restriction is
static, the indicated
DL power
restriction is
maintained over
the subsequent
subframes.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞, −11,
defined in TS
−10, −9,
36.213 [11].
−8, −7, −6,
−5, −4, −3,
−2, −1, 0,
1, 2,3 , . . .)
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . .)
antenna ports for
Antenna Ports
cell-specific
reference signals)
defined in TS
36.211 [10]
P_B
M
INTEGER
P B is defined in TS
—
—
(0 . . . 3, . . .)
36.213 [11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . .)
Predicted Number
Impact
Of Occupied
PDCCH OFDM
Symbols (see TS
36.211 [10]).
Value 0 means “no
prediction is
available”.
Extended
O
BIT STRING
Each position in
RNTP Per
(6 . . . 4290, . . .)
the bitmap
PRB
represents a PRB
in a subframe, for
which value “1”
indicates ‘no
promise on the Tx
power is given’
and value “0”
indicates ‘Tx not
exceeding RNTP
threshold.’
The first bit
corresponds to
PRB 0 of the first
subframe for
which the
extended RNTP
per PRB IE is
valid, the second
bit corresponds to
PRB 1 of the first
subframe for
which the
extended RNTP
per PRB IE is
valid, and so on.
The length of the
bit string is an
integer (maximum
39) multiple of
nDLRB, which is
defined in TS
36.211 [10].
The bit string may
span across
multiple
contiguous
subframes.
The pattern across
contiguous
subframes (formed
by RNTP per PRB
and extended
RNTP per PRB) is
continuously
repeated
RNTP per
0 . . . 1
PRB start time
>Starting SFN
M
INTEGER
SFN of the radio
(0 . . . 1023, . . .)
frame containing
the first subframe
when the RNTP
Per PRB IE is
valid.
>Starting
M
INTEGER
Subframe number,
Subframe
(0 . . . 9, . . .)
within the radio
Index
frame indicated by
the Start SFN IE,
of the first
subframe when the
RNTP Per PRB IE
is valid.
[0172] The second alternative is given below.
[0000]
TABLE C4
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
ERNTP Per
M
BIT STRING
Each position in
—
—
PRB and
(12 . . . 220, . . .)
the bitmap
subframe
represents a
PRB in a
subframe, for
which the value
“xx” indicates
how the
transmission
power in a
resource block is
mapped relative
to the three
power
thresholds:
00 - power level
not exceeding
the LPTH
01 - power level
between LPTH
and MPTH;
10 - power level
between MPTH
and HPTH;
11 - no promise
on the Tx power
is given.
The first 2 bits
correspond to
PRB 0 of the first
subframe for
which the IE is
valid, the
following 2 bits
correspond to
PRB 1 of the first
subframe for
which the IE is
valid, and so on.
The bit string
may span across
multiple
contiguous
subframes.
The length of the
bit string is an
integer
(maximum 40)
multiple of
nDLRB. The
parameter is
defined in TS
36.211 [10].
The ERNTP
pattern is
continuously
repeated with a
periodicity
indicated in
Periodicity.
Transmitted
power levels
LPTH (Low
M
ENUMERATED
Lower RNTP
—
—
Power
(−∞, −11,
power threshold,
Threshold)
−10, −9, −8,
using the
−7, −6, −5, −4,
RNTP threshold
−3, −2, −1, 0,
defined in TS
1, 2, 3, . . .)
36.213 [11].
MPTH
M
ENUMERATED
Medium RNTP
(Medium
(−∞, −11,
power threshold,
Power
−10, −9, −8,
using the
Threshold)
−7, −6, −5, −4,
RNTP threshold
−3, −2, −1, 0,
defined in TS
1, 2, 3, . . .)
36.213 [11].
HPTH (High
M
ENUMERATED
Higher RNTP
Power
(−∞, −11,
power threshold,
Threshold)
−10, −9, −8,
using the
−7, −6, −5, −4,
RNTP threshold
−3, −2, −1, 0,
defined in TS
1, 2, 3, . . .)
36.213 [11].
Subframe
sequence
definition
>Start SFN
M
INTEGER
SFN of the radio
(0 . . . 1023)
frame containing
the first subframe
where the RNTP
Per PRB Per
Subframe IE is
valid.
>Start
M
INTEGER
Subframe
Subframe
(0 . . . 39)
number, within
Number
the radio frame
indicated by the
Start SFN IE, of
the first subframe
when the RNTP
Per PRB Per
Subframe IE is
valid.
No. of
M
1 . . . 40
No. of subframes
subframes
for which is
defined the
bitstream
Periodicity
1 . . . 40
The number of
subframes after
which the bit
pattern is
repeated
Number Of
M
ENUMERATED
P (number of
Cell-specific
(1, 2, 4,
antenna ports for
Antenna Ports
. . .)
cell-specific
reference
signals) defined
in TS 36.211 [10]
P_B
M
INTEGER
P B is defined in
(0 . . . 3, . . .)
TS 36.213 [11].
Embodiment D
[0173] D1. Introduction
[0174] In the following we provide our views on CSI and eRNTP exchange, as well as proposals containing the required message structures.
[0175] D2. Discussion
[0176] D2.1 CSI Exchange: Configuring CSI Processes
[0177] The concept of CSI processes was defined in Rel.11 to enable CSI feedback from a UE to its serving eNB. The CSI feedback is determined for each CSI process according to the serving TP and interference hypothesis configured in that process. Each CSI process that is configured for a UE, comprises a set of resource elements on which non-zero power CSI-RSs are sent and a channel estimate is obtained by that UE using observations received on those resource elements.
[0178] In addition, a set of resource elements is also indicated by the CSI process (referred to as interference measurement resources (IMRs)) on which the UE estimates the covariance of the interference it observes. The channel and covariance estimates are together used by the UE to determine and send its feedback report corresponding to that CSI process. Multiple such CSI processes (up-to 4) can be configured for a UE, each process corresponding to a different choice of signal or interference hypothesis. Moreover, in the scenario in which fast switching of the serving TP is not possible, different CSI processes that are configured for any given UE typically correspond to different choices of interference hypothesis.
[0179] Note from the brief discussion above that in the event the interference hypothesis of a configured CSI process presumes muting from a TP (that is a dominant interferer for the UE of interest) which is controlled by the neighboring eNB, coordination among the eNBs is required in order to ensure that the interference estimated by the UE on the constituent IMRs is consistent with the assumed hypothesis. Another similar event that requires coordination is if the non-zero power CSI-RSs indicated in the CSI process must be interference protected in order to ensure reliable channel estimation at the UE. In both these events, the dominant interferer that is controlled by the neighboring eNB must be muted on certain resource elements. Thus, a mechanism (with appropriate signaling) should be available to share the CSI-RS (comprising non-zero power CSI-RSs and IMRs) configurations between eNBs, which would facilitate configuration of CSI processes across multiple eNBs.
[0180] Once the CSI processes are configured, the CSI exchanged among eNBs over the backhaul should include the respective CSI process configuration information, in order to convey the conditions under which the CSI was measured by the UE. This configuration information includes non-zero power CSI-RS information and IMR information (comprising the subframe indices and zero-power CSI-RS information). Since this configuration is anyway informed to the UE via RRC (or higher layer) signaling, the same information can be reused as a container to convey the configuration to the neighboring eNB.
[0181] Another way of conveying this configuration information is through a look-up-table. A look-up-table mapping an index to one or more distinct applied CSI process configurations can be constructed for each eNB. Here, by an applied CSI process we mean a process that is used by at-least one UE served by that eNB to measure its CSI. Such a table can be exchanged among neighbors first and from then on the configuration information can be exchanged via indices. The total number of configurations in the table can be limited in order to limit signaling overhead.
[0182] Suitable values for the number of configurations in this table are either 8 or 16 or 32.
[0183] D2.2 CSI Exchange: Contents
[0184] One eNB can send CSI report pertaining to one or more of UEs to a neighboring eNB. For each UE, the CSI that the eNB sends to a neighbor can comprise:
[0185] CQI: up-to 2 CQIs, each including a wideband component and possible sub-band differential components
[0186] RI: one wideband component
[0187] We note that the PMI was excluded from the CSI exchange report [1]. The justification for this exclusion was to minimize the overhead and the fact that PMI can depend on fast changing channel information, thus reducing its utility over non ideal backhaul with a higher latency. However, in the absence of PMI the use of RI is limited. Indeed, any rank greater than 1 will convey only 2 CQI(s), one for each of the two codewords. No further information about the (average) spatial directions seen by that UE can be deduced by the eNB receiving the report. As a result, reporting the RI should be made optional. Moreover, the eNB requesting the CSI report should be able to specify whether or not it would like to receive RI reports. Similarly, the eNB requesting the CSI reports should be able to specify whether or not it requires subband specific CQI reports. This can be achieved by setting a bit (in the measurement request) to be 0 if rank is not requested and 1 otherwise. Another bit can be set to 0 if subband CQIs are not requested and 1 otherwise.
[0188] Processing (filtering or subsampling) of the short-term CSI (received via over-the-air signaling) at an eNB prior to exchange should be permitted.
[0189] One use case for this is when the periodicity of the CSI report that is requested by eNB1 to its neighbor eNB2, is larger than the over-the-air CSI signaling periodicity configured by eNB2. In this case eNB2 has to do some processing (such as subsampling or averaging) of the reports it receives before it sends it to eNB1. In this context, we note that the subsampling employed by eNB2 should be understood by eNB1 (if needed additional signaling can be added to ensure this). One possible way this can be accomplished (without any signaling overhead) is for eNB2 to use the subsampling factor determined by a pre-determined rule (known to or configured for all eNBs in advance) that outputs a subsampling factor, given the requested periodicity and CSI process configuration as inputs. On the other hand, averaging or scaling or filtering employed by eNB2 can be transparent to the receiving eNB.
[0190] One of the goals of CSI exchange is to facilitate centralized RRM [3]. In a scenario with centralized RRM, the central node receiving the CSI reports should be able to keep track of the CSI information received for each particular UE, over all the received CSI reports. This can be achieved by including a UE identifier in each CSI report for each UE whose CSI is conveyed in that report. We want to include a unique ID for each user so that the receiving node knows which ones among all the reports that it receives, belong that user. This will be useful for RRM. Otherwise the receiving eNB will regard each received report as belonging to a distinct user. This can lead to sub-optimal resource allocation.
[0191] D2.3 eRNTP Exchange
[0192] Our view on eRNTP exchange is captured in a corresponding proposal attached in the end of this embodiment.
[0193] We note that the RNTP (i.e., downlink (DL) power restriction) for the first subframe is always conveyed. If no information about the DL power restriction on any subsequent subframe is conveyed, then the one conveyed for the first subframe can be assumed to remain static (i.e., applicable over subsequent subframes).
[0194] We also present several variations, one of which includes the use of multiple thresholds
[0195] D3. Conclusion
[0196] We discussed the necessary X2 message to support CSI and eRNTP exchange for inter-eNB CoMP and presented corresponding proposals.
[0197] Proposal:
[0198] 9.1.2.11 Resource Status Request
[0199] This message is sent by an eNB 1 to a neighbouring eNB 2 to initiate the requested measurement according to the parameters given in the message.
[0200] Direction: eNB 1 →eNB 2 .
[0000]
TABLE D1
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
Message
M
9.2.13
YES
reject
Type
eNB1
M
INTEGER
Allocated by
YES
reject
Measurement
(1 . . . 4095, . . .)
eNB 1
ID
eNB2
C-ifRegistrationRequestStop
INTEGER
Allocated by
YES
ignore
Measurement
(1 . . . 4095, . . .)
eNB 2
ID
Registration
M
ENUMERATED
A value set to
YES
reject
Request
(start, stop,
“stop”, indicates
. . .)
a request to stop
all cells
measurements.
Report
O
BITSTRING
Each position in
YES
reject
Characteristics
(SIZE(32))
the bitmap
indicates
measurement
object the eNB 2
is requested to
report.
First Bit = PRB
Periodic,
Second Bit =
TNL load Ind
Periodic,
Third Bit = HW
Load Ind
Periodic,
Fourth Bit =
Composite
Available
Capacity
Periodic, this bit
should be set to
1 if at least one
of the First,
Second or Third
bits is set to 1,
Fifth Bit = ABS
Status
Periodic, Xth Bit =
UE-CSI
Periodic.
Other bits shall
be ignored by
the eNB 2 .
Cell To
1
Cell ID list for
YES
ignore
Report
which
measurement is
needed
>Cell To
1 . . .
EACH
ignore
Report Item
<maxCellineNB>
>>Cell ID
M
ECGI
—
—
9.2.14
Reporting
O
ENUMERATED
YES
ignore
Periodicity
(1000 ms, 2000 ms,
5000 ms, 10000 ms,
. . .)
Partial
O
ENUMERATED
Included if
YES
ignore
Success
(partial success
partial success
Indicator
allowed, . . .)
is allowed
CSI
O
BITSTRING
Each position in
YES
ignore
Measurement
(SIZE(2))
the bitmap
Report type
indicates the
type of CSI
measurement to
report.
First bit = Rank,
Second
bit = subband
CQI.
((Reporting
O
ENUMERATED
Periodicity for
YES
ignore
Periodicity of
(5 ms, 10 ms,
CSI
CSI
20 ms, 40 ms,
Measurement
Measurement
80 ms, aperiodic,
Report Periodic
Report
. . .)
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value
is 256.
Condition
Explanation
IfRegistrationRequestStop
This IE shall be present if the Registration Request IE is
set to the value “stop”.
[0201] 9.1.2.14 Resource Status Update
[0202] This message is sent by eNB 2 to neighbouring eNB 1 to report the results of the requested measurements.
[0203] Direction: eNB 2 →eNB 1 .
[0000]
TABLE D2
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
Message Type
M
9.2.13
YES
ignore
eNB1
M
INTEGER
Allocated by
YES
reject
Measurement
(1 . . . 4095, . . .)
eNB 1
ID
eNB2
M
INTEGER
Allocated by
YES
reject
Measurement
(1 . . . 4095, . . .)
eNB 2
ID
Cell
1
YES
ignore
Measurement
Result
>Cell
1 . . .
EACH
ignore
Measurement
<maxCellineNB>
Result
Item
>>Cell ID
M
ECGI
9.2.14
>>Hardware
O
9.2.34
Load
Indicator
>>S1 TNL
O
9.2.35
Load
Indicator
>>Radio
O
9.2.37
Resource
Status
>>Composite
O
9.2.44
YES
ignore
Available
Capacity
Group
>>ABS
O
9.2.58
YES
ignore
Status
>> UE-CSI
O
9.2.x1
YES
ignore
Report
Range bound
Explanation
maxCellineNB
Maximum no. cells that can be served by an eNB. Value
is 256.
[0204] 9.2.x1 UE-CSI Report
[0205] This IE provides UE-CSI information for a set of UEs served by eNB 2 .
[0000]
TABLE D3
IE/Group
IE type and
Semantics
Name
Presence
Range
reference
description
UE subset CSI
1 . . . <maxUEsubsetCSIReport>
Report
>UE ID
M
BIT STRING
ID of the UE
(SIZE (16))
served by the cell
in eNB 2 .
>UE-CSI
1 . . . <maxUE-CSIprocess>
process
information
>>Rank
O
BIT STRING
The rank indicator
Indicator
(SIZE (3))
IE is present only if
it is requested in
the associated
request. In that
case Cf. TS 36.213
[7.2.3].
>>Wideband
M
BIT STRING
Cf. TS 36.213
CQI For
(SIZE (4))
[7.2.3].
Codeword 0
>>Wideband
O
BIT STRING
Cf. TS 36.213
CQI For
(SIZE (4))
[7.2.3].
Codeword 1
>>Subband
0 . . . <maxCQISubbands >
This IE is present
CQI List
only if associated
request wants
subband CQI
>>>Subband
O
BIT STRING
Cf. TS 36.213
CQI for
(SIZE (2))
[7.2.3].
codeword 0
>>>Subband
O
BIT STRING
Cf. TS 36.213
CQI for
(SIZE (2))
[7.2.3].
codeword 1
>>UE-CSI
M
FFS
CSI process
process
configuration
Configuration
information.
information
Range bound
Explanation
maxUEsubsetCSIReport
Maximum UE subset size for which UE-CSI can be
reported. The value is 32.
maxUE-CSIProcess
Maximum number of CSI processes per-UE. The value
is 4.
maxCQISubbands
Maximum number of subbands for UE CQI reporting.
The value is 28.
[0206] Alternatively, the parameter maxUEsubsetCSIReport can be 8 or 64. Further, optionally, the UE-ID can have a more compact representation using say 8 bits or 6 bits or 5 bits (equivalently 256 or 64 or 32 possible indices from a configurable table).
[0207] Next, we consider the case when subband indices have to be indicated. This is important to accommodate feedback modes that involve UE selected subband feedback.
[0000]
TABLE D4
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
UE subset CSI Report
1 . . . <maxUEsubsetCSIReport>
>C-RNTI
M
BIT STRING
ID of the UE
(SIZE (16))
served by the cell
in eNB 2 .
Defined in TS
36.331.
>UE-CSI process
1 . . . <maxUE-CSIprocess>
information
>>Rank Indicator
O
BIT STRING
The rank indicator
(SIZE (3))
IE is present only if
it is requested in
the associated
request. In that
case Cf. TS 36.213
[7.2.3].
>>Wideband CQI For
M
BIT STRING
Codeword 0
(SIZE (4))
>>Wideband CQI For
O
BIT STRING
Codeword 1
(SIZE (4))
>>Subband CQI List
0 . . . <maxCQISubbands >
This IE is present
only if associated
request wants
subband CQI
>>>Subband CQI for
O
BIT STRING
codeword 0
(SIZE (4))
>>>Subband CQI for
O
BIT STRING
codeword 1
(SIZE (4))
>>>Subband index
O
INTEGER
Included in case of
(0 . . . 27, . . . )
UE selected
subband CQI
reporting.
>>UE-CSI process
M
FFS
CSI process
Configuration
configuration
information
information.
[0208] Note that as an alternative in the above tables, for each CQI the bit string field of 4 bits (2 bits) can be replaced by INTEGER (0..15, . . . ) (INTEGER (0..7, . . . )).
[0209] In another alternative the sub band indices can be conveyed by means of a combinatorial index which is described next.
[0210] The idea here is that depending on the number of PRBs (or RBs for short) in the downlink available at sending eNB2 (a parameter which is known or conveyed separately to the receiving eNB1), the set of all possible subband selections that can be made together with the subband size for each feedback mode can be deduced by eNB1.
[0211] For example when 110 RBs are available at eNB2 (and this number is conveyed to eNB1) eNB1 can deduce that for a UE configured under:
[0212] Aperiodic, Mode 2-*: 6 UE selected subband indices
[0213] A subframe is composed of 28 subbands. Among 28 subbands, 6 subbands are selected by the UE. The number of PRBs in the subbands is 4 except for the last one; the number of PRBs in the last subband is 2 (4*27+2=110).
[0214] For Aperiodic, Mode 3-*: 14 higher layer-configured sub bands
[0215] A subframe is composed of 14 subbands. The number of PRBs in the subband is 8 except for the last one; the number of PRBs in the last subband is 6 (8*13+6=110).
[0216] For Periodic, Mode 2-*: 4 UE selected subband indices (with an additional constraint on choosing one sub band per bandwidth portion or part)
[0217] A subframe is composed of 14 subbands. Among 14 subbands, 4 subbands are selected by the UE. The number of PRBs in the subbands is 8 except for the last one; the number of PRBs in the last subband is 6 (8*13+6=110).
[0218] Then, considering all possible feasible subband selections under all the aforementioned feedback modes, it is possible to assign a unique label to each distinct feasible selection of sub bands. All possible such labels together decide the range of a combinatorial index R. As a result, knowing the value of R the receiving eNB can deduce the subband selection. The associated CQIs (one for each subband in the indicated selection) can be ordered in the increasing order of the frequency range represented by the indicated subbands. Each such CQI can be conveyed using full representation (i.e., using 16 possibilities) which can then be directly used by the receiving eNB1.
[0000]
TABLE D5
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
UE subset CSI Report
1 . . . <maxUEsubsetCS/Report>
>C-RNTI
M
BIT STRING
ID of the UE
(SIZE (16))
served by the cell
in eNB 2 .
Defined in TS
36.331.
>UE-CSI process
1 . . . <maxUE-CSIprocess>
information
>>Rank Indicator
O
BIT STRING
The rank indicator
(SIZE (3))
IE is present only if
it is requested in
the associated
request. In that
case Cf. TS 36.213
[7.2.3].
>>Wideband CQI For
M
BIT STRING
Codeword 0
(SIZE (4))
>>Wideband CQI For
O
BIT STRING
Codeword 1
(SIZE (4))
>>combinatorial
O
Integer FFS
This IE is present
index
only if associated
request wants
subband CQI
>>>Subband CQI List
0 . . . <maxCQISubbands >
The number of
subbands in the list
as well as their
respective indices
and sizes are
deduced from the
combinatorial index.
>>>>Subband CQI
M
BIT STRING
for codeword 0
(SIZE (4))
>>>>Subband CQI
O
BIT STRING
for codeword 1
(SIZE (4))
>>UE-CSI process
M
FFS
CSI process
Configuration
configuration
information
information.
[0219] UE Configuration Independent Coding Structure
[0220] A coding structure for signaling CSI over X2 in a UE-configuration independent way is shown in Table I1. In this structure, a subband is defined as a set of contiguous PRBs having the same CQI value. The subband partitioning is left to the sending eNB2 implementation, and is not restricted by the UE's CSI reporting configuration. Each indicated CQI follows the definition of a 4 bit CQI (Cf. TS 36.213). This allows for the sending eNB2 to process the CSI it receives from the UE in any manner as long as each indicated CQI is consistent with the basic CQI definition. The receiving eNB1 can directly use these CQIs while being agnostic to how they were procured and processed by eNB1.
[0000]
TABLE D6
UE configuration independent coding structure
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI per UE
1 . . . <maxnoofUE-CSI>
>C-RNTI
M
BIT STRING
(SIZE (16))
>CSI per Interference
1 . . . <maxnoofInterferenceHypothesis >
Hypotheses
>>Interference Hypothesis
M
[FFS]
Information
>>Wideband CQI for
M
INTEGER(0 . . . 15, . . . )
Codeword 0
>>Wideband CQI for
O
INTEGER(0 . . . 15, . . . )
Codeword 1
>>Rank Indication
M
INTEGER(1 . . . 8, . . . )
Defined in TS
36.213 [11].
>>Subband CQI List
0 . . . <maxnoofSubband>
Subbands are listed
in the order of
increasing
frequency.
>>>Subband Start
O
INTEGER(0 . . . 109, . . . )
PRB number of the
first PRB in the
subband. If this IE is
not present, the
subband is
contiguous with the
previous subband in
the list, or starts
with PRB 0 if this is
the first subband in
the list.
>>>Subband Size
O
INTEGER(1 . . . 110, . . . )
Number of
contiguous PRBs in
the subband. If this
IE is not present,
the value is the
same as the
previous subband in
the list.
>>>Subband CQI for
M
INTEGER(0 . . . 15, . . . )
Codeword 0
>>>Subband CQI for
O
INTEGER(0 . . . 15, . . . )
Codeword 1
[0221] We note here that reporting full (complete) CQI (with 16 possibilities) for each indicated subband CQI instead of differential CQI is useful since otherwise the receiving eNB1 may not know how to combine a corresponding wideband CQI and differential sub-band CQI (with fewer than 16 possibilities) in order to obtain the full CQI for that subband, for instance, in the case that the precise feedback mode configured for the UE of interest under that CSI process is not conveyed to the receiving eNB1. We note here also that it might be desirable to not impose restrictions on sending eNB2 on how it combines reports from multiple different feedback modes configured for that UE under the same CSI process. Then, note that when aperiodic feedback mode 3-1 is configured for the UE (by eNB2), the UE reported sub band CQI is encoded differentially with respect to the corresponding wideband CQI using 2 bits representing differential values {-2, 0,1,2}. On the other hand, in the case of aperiodic feedback mode 2-0 or 2-2, only the best M-average is reported by the UE by differentially encoding it with respect to a corresponding wideband CQI using 2 bits representing differential values {1, 2,3,4}. Further, in case of periodic feedback mode 2-1 the CQI corresponding to codeword-1 for each UE selected subband within a bandwidth part can itself be of 4 bits, whereas that of codeword-2 (when RI>1) is differentially encoded with respect to CQI of codeword-1 using 3 bits.
[0222] It becomes apparent from the above discussion that a transparent way of conveying CQI (without having to convey all details regarding to one or more feedback modes configured under that CSI process for that UE) is to allow for full (complete) CQI for each indicated subband.
[0223] Another issue that is important, is to ensure that the RI and CQIs conveyed by eNB2 to eNB1 in a UE CSI report are mutually consistent, i.e., all the reported CQIs are computed by the UE for the same RI (which is identical to the one in the Rank Indication IE when the latter is present). This issue is important to address because under certain feedback modes (such as periodic mode 2-1) the RI and the wideband CQI(s) as well as the subband CQI(s) for one or more bandwidth portions can be reported by the UE on different subframes. Thus, depending on the periodicity defined by eNB1 in its CSI request, it can happen that the latest RI available for the UE under the CSI process, can be different from the one for which the most recent CQI(s) are computed. In such a case, the sending eNB2 should ensure that its CSI report is consistent, for instance by using the RI value for which the most recently available CQI(s) have been computed.
[0224] The variation (which allows the requesting eNB to specify whether or not it wants to receive subband CQI(s) or Rank Indication is provided below. In this context, we note that since the requesting eNB1 has no control over how eNB2 configures CSI processes (and constituent feedback modes) for its users, it should be in any case able to exploit different type of CSI reports (wideband only or wideband and subband).
[0000]
TABLE D7
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI per UE
1 . . . <maxnoofUE-CSI>
>C-RNTI
M
BIT STRING
(SIZE (16))
>CSI per Interference
1 . . . <maxnoofInterferenceHypothesis >
Hypotheses
>>Interference Hypothesis
M
[FFS]
Information
>>Wideband CQI for
M
INTEGER(0 . . . 15, . . . )
Codeword 0
>>Wideband CQI for
O
INTEGER(0 . . . 15, . . . )
Codeword 1
>>Rank Indication
O
INTEGER(1 . . . 8, . . . )
The rank indication
IE is present only if
it is requested in the
associated request.
In that case it
follows the definition
in TS 36.213 [11].
>>Subband CQI List
0 . . . <maxnoofSubband>
This IE is present
only if associated
request wants
subband CQI. In
that case subbands
are listed in the
order of increasing
frequency.
>>>Subband Start
O
INTEGER(0 . . . 109, . . . )
PRB number of the
first PRB in the
subband. If this IE is
not present, the
subband is
contiguous with the
previous subband in
the list, or starts
with PRB 0 if this is
the first subband in
the list.
>>>Subband Size
O
INTEGER(1 . . . 110, . . . )
Number of
contiguous PRBs in
the subband. If this
IE is not present,
the value is the
same as the
previous subband in
the list.
>>>Subband CQI for
M
INTEGER(0 . . . 15, . . . )
Codeword 0
>>>Subband CQI for
O
INTEGER(0 . . . 15, . . . )
Codeword 1
[0225] Another variation which allows for further simplification at the expense of not being bit efficient is as follows. Here the full CQIs for all possible subbands (which can be determined by the number of PRBs in the downlink available at eNB2) are always conveyed for a UE under the CSI process. In case the sub band CQI is not reported by a UE under the configured feedback mode for a subband, the sending eNB2 simply uses the wideband CQI value for that subband.
[0226] 9.2.19 Relative Narrowband Tx Power (RNTP)
[0227] This IE provides an indication on DL power restriction per PRB in a cell and other information needed by a neighbour eNB for interference aware scheduling.
[0000]
TABLE D8
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP Per
M
BIT
Each position in
—
—
PRB
STRING
the bitmap
(6 . . . 110, . . .)
represents a
n PRB value (i.e.
first bit = PRB 0
and so on), for
which the bit
value
represents
RNTP (n PRB ),
defined in TS
36.213 [11].
Value 0
indicates “Tx not
exceeding
RNTP
threshold”.
Value 1
indicates “no
promise on the
Tx power is
given”.
This IE is used
to indicate DL
power restriction
per PRB for the
first subframe.
In case the DL
power restriction
is static, the
indicated DL
power restriction
is maintained
over the
subsequent
subframes.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞, −11,
defined in TS
−10, −9,
36.213 [11].
−8, −7, −6,
−5, −4, −3,
−2, −1, 0,
1, 2, 3,
. . .)
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4,
antenna ports
Antenna
. . .)
for cell-specific
Ports
reference
signals) defined
in TS 36.211
[10]
P_B
M
INTEGER
P B is defined in
—
—
(0 . . . 3, . . .)
TS 36.213 [11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . .)
Predicted
Impact
Number Of
Occupied
PDCCH OFDM
Symbols (see
TS 36.211 [10]).
Value 0 means
“no prediction is
available”.
Extended
O
BIT
Each position in
RNTP Per
STRING
the bitmap
PRB
(6 . . . 4290,
represents a
. . .)
PRB in a
subframe, for
which value “1”
indicates ‘no
promise on the
Tx power is
given’ and value
“0” indicates ‘Tx
not exceeding
RNTP
threshold.’
The first bit
corresponds to
PRB 0 of the
first subframe
for which the
extended RNTP
per PRB IE is
valid, the
second bit
corresponds to
PRB 1 of the
first subframe
for which the
extended RNTP
per PRB IE is
valid, and so on.
The length of
the bit string is
an integer
(maximum 39)
multiple of N RB DL .
N RB DL is
defined in TS
36.211 [10].
The bit string
may span
across multiple
contiguous
subframes.
The pattern
across
contiguous
subframes
(formed by
RNTP per PRB
and extended
RNTP per PRB)
is continuously
repeated.
RNTP per
0 . . . 1
PRB start
time
>Starting
M
INTEGER
SFN of the radio
SFN
(0 . . . 1023,
frame containing
. . .)
the first subframe
when the RNTP
Per PRB IE is
valid.
>Starting
M
INTEGER
Subframe
Subframe
(0 . . . 9, . . .)
number, within
Index
the radio frame
indicated by the
Start SFN IE, of
the first subframe
when the RNTP
Per PRB IE is
valid.
[0228] An alternate Table for RNTP enhancement is given below.
[0000]
TABLE D9
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP per PRB
M
BIT
Each position in
—
—
STRING
the bitmap
(6 . . . 110, . . . )
represents a
n PRB value (i.e.
first bit = PRB 0
and so on), for
which the bit
value
represents
RNTP (n PRB ),
defined in TS
36.213 [11].
Value 0
indicates “Tx not
exceeding
RNTP
threshold”.
Value 1
indicates “no
promise on the
Tx power is
given”.
This IE is
ignored if the
RNTP per PRB
per subframe IE
is present.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞,
defined in TS
−11, −10, −9,
36.213 [11].
−8, −7, −6, −5,
−4, −3, −2, −1,
0, 1, 2, 3, . . . )
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . . )
antenna ports
Antenna Ports
for cell-specific
reference
signals) defined
in TS 36.211
[10]
P_B
M
INTEGER
P B is defined in
—
—
(0 . . . 3, . . . )
TS 36.213 [11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . . )
Predicted
Impact
Number Of
Occupied
PDCCH OFDM
Symbols (see
TS 36.211 [10]).
Value 0 means
“no prediction is
available”.
RNTP Per
O
BIT
Each position in
PRB per
STRING
the bitmap
subframe
(6 . . . 4400, . . . )
represents a
PRB in a
subframe, for
which value “1”
indicates ‘no
promise on the
Tx power is
given’ and value
“0” indicates ‘Tx
not exceeding
RNTP
threshold.’
The first bit
corresponds to
PRB 0 of the
first subframe
for which the
RNTP per PRB
per subframe IE
is valid, the
second bit
corresponds to
PRB 1 of the
first subframe
for which the
RNTP per PRB
per subframe IE
is valid, and so
on.
The length of
the bit string is
an integer
(maximum 40)
multiple of N RB DL .
N RB DL is
defined in TS
36.211 [10].
The bit string
may span
across multiple
contiguous
subframes.
The pattern
across
contiguous
subframes
formed by
RNTP per PRB
per subframe IE
is continuously
repeated.
RNTP per
0 . . . 1
PRB per
subframe
start time
>Starting
M
INTEGER
SFN of the radio
SFN
(0 . . . 1023, . . . )
frame containing
the first subframe
when the RNTP
Per PRB Per
Subframe IE is
valid.
>Starting
M
INTEGER
Subframe
Subframe
(0 . . . 9, . . . )
number, within
Index
the radio frame
indicated by the
Start SFN IE, of
the first subframe
when the RNTP
Per PRB Per
Subframe IE is
valid.
[0229] Another alternate Table for RNTP enhancement is given below.
[0000]
TABLE D10
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP per PRB
M
BIT
Each position in
—
—
STRING
the bitmap
(6 . . . 110, . . . )
represents a
n PRB value (i.e.
first bit = PRB 0
and so on), for
which the bit
value
represents
RNTP (n PRB ),
defined in TS
36.213 [11].
Value 0
indicates “Tx not
exceeding
RNTP
threshold”.
Value 1
indicates “no
promise on the
Tx power is
given”.
This IE is
ignored if the
RNTP per PRB
per subframe IE
is present.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞,
defined in TS
−11, −10, −9,
36.213 [11].
−8, −7, −6, −5,
−4, −3, −2, −1,
0, 1, 2, 3, . . . )
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . . )
antenna ports
Antenna Ports
for cell-specific
reference
signals) defined
in TS 36.211
[10]
P_B
M
INTEGER
P B is defined in
—
—
(0 . . . 3, . . . )
TS 36.213 [11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . . )
Predicted
Impact
Number Of
Occupied
PDCCH OFDM
Symbols (see
TS 36.211 [10]).
Value 0 means
“no prediction is
available”.
RNTP Per
O
BIT
Each position in
PRB per
STRING
the bitmap
subframe
(6 . . . 4400, . . . )
represents a
PRB in a
subframe, for
which value “1”
indicates
‘resource with no
utilization
constraints’ and
value “0”
indicates
‘interference
protected
resource.’
The first bit
corresponds to
PRB 0 of the
first subframe
for which the
RNTP per PRB
per subframe IE
is valid, the
second bit
corresponds to
PRB 1 of the
first subframe
for which the
RNTP per PRB
per subframe IE
is valid, and so
on.
The length of
the bit string is
an integer
(maximum 40)
multiple of N RB DL .
N RB DL is
defined in TS
36.211 [10].
The bit string
may span
across multiple
contiguous
subframes.
The pattern
across
contiguous
subframes
formed by
RNTP per PRB
per subframe IE
is continuously
repeated.
RNTP per
0 . . . 1
PRB per
subframe
start time
>Starting
M
INTEGER
SFN of the radio
SFN
(0 . . . 1023, . . . )
frame containing
the first subframe
when the RNTP
Per PRB Per
Subframe IE is
valid.
>Starting
M
INTEGER
Subframe
Subframe
(0 . . . 9, . . . )
number, within
Index
the radio frame
indicated by the
Start SFN IE, of
the first subframe
when the RNTP
Per PRB Per
Subframe IE is
valid.
[0230] Another alternative using multiple thresholds conveyed via 2 bits is given below.
[0000]
TABLE D11
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
ERNTP Per
M
BIT
Each position in
—
—
PRB and
STRING
the bitmap
subframe
(12 . . . 220, . . . )
represents a
PRB in a
subframe, for
which the value
“xx” indicates
how the
transmission
power in a
resource block
is mapped
relative to the
two power
thNresholds:
00—power level
not exceeding
the LPTH
01—power level
between LPTH
and MPTH;
10—power level
between MPTH
and HPTH;
11—no promise
on the Tx power
is given.
The first 2 bits
correspond to
PRB 0 of the
first subframe
for which the IE
is valid, the
following 2 bits
correspond to
PRB 1 of the
first subframe
for which the IE
is valid, and so
on.
The bit string
may span
across multiple
contiguous
subframes.
The length of
the bit string is
an integer
(maximum 40)
multiple of. The
parameter is
defined in TS
36.211 [10].
The ERNTP
pattern is
continuously
repeated with a
periodicity
indicated in
Periodicity.
Transmitted
power levels
LPTH (Low
M
ENUMERATED
Lower RNTP
—
—
Power
(−∞,
power
Threshold)
−11, −10, −9,
threshold, using
−8, −7, −6, −5,
the
−4, −3, −2, −1,
RNTP threshold
0, 1, 2, 3, . . . )
defined in TS
36.213 [11].
MPTH
M
ENUMERATED
Medium RNTP
(Medium
(−∞,
power
Power
−11, −10, −9,
threshold, using
Threshold)
−8, −7, −6, −5,
the
−4, −3, −2, −1,
RNTP threshold
0, 1, 2, 3, . . . )
defined in TS
36.213 [11].
HPTH (High
M
ENUMERATED
Higher RNTP
Power
(−∞,
power
Threshold)
−11, −10, −9,
threshold, using
−8, −7, −6, −5,
the RNTP threshold
−4, −3, −2, −1,
defined in TS
0, 1, 2, 3, . . . )
36.213 [11].
Subframe
sequence
definition
>Start SFN
M
INTEGER
SFN of the radio
(0 . . . 1023)
frame
containing the
first subframe
where the
RNTP Per PRB
Per Subframe
IE is valid.
>Start
M
INTEGER
Subframe
Subframe
(0 . . . 39)
number, within
Number
the radio frame
indicated by the
Start SFN IE, of
the first
subframe when
the RNTP Per
PRB Per
Subframe IE is
valid.
No. of
M
1 . . . 40
No. of
subframes
subframes for
which is defined
the bitstream
Periodicity
1 . . . 40
The number of
subframes after
which the bit
pattern is
repeated
Number Of
M
ENUMERATED
P (number of
Cell-specific
(1, 2,
antenna ports
Antenna Ports
4, . . . )
for cell-specific
reference
signals) defined
in TS 36.211
[10]
P_B
M
INTEGER
P B is defined in
(0 . . . 3, . . . )
TS 36.213 [11].
[0231] The point in the table given above is that since the choice ‘11’ already indicates no promise on the power level (which covers the case of transmit power being arbitrarily high) we can use three thresholds (instead of two) since there is no need to convey that the power level is greater than HPTH (as this is subsumed by ‘11’).
[0232] However, one problem with indicating multiple thresholds is that the current CoMP hypothesis (implicitly) assumes just one threshold. In this sense there is a mismatch between using multiple thresholds in eRNTP and not in the CoMP hypothesis. Consequently, the full potential of multiple thresholds may not be realized inspire of the additional overhead.
[0233] Suppose that there are L subband selection types denoted by {(N 1 , q 1 ), . . . , (N L , q L )}, where the l th selection type is defined by N l , q l which denote the total number of subbands and the number of subbands that must be selected, respectively, under that type. Note that under each selection type the size of each subband is fixed and known a-priori. Further, suppose that there are J bandwidth portions, each portion comprising S j , 1≦j≦J subbands. Only one subband is selected from the S j subbands in each bandwidth portion jε{1, . . . , J}. Further since the user sequentially reports its CSI report for the bandwidth portions, we can impose a nested structure on the corresponding exchange of CSI from sending eNB2 to receiving eNB1. In particular, we impose the structure under which the CSI of any subband in the j th portion is sent only if the CSI of a subband in each of the preceeding j−1 bandwidth portions are sent. This structure enables efficient exchange of CSI without any loss of generality. Thus, overall there are L+J different selection types possible (with the last J types associated with the selections from bandwidth portions). Then, each selection in the total number of distinct subband selections can be identified by a combinatorial index R whose range is given by
[0000]
0
,
…
,
∑
j
=
1
L
(
N
j
q
j
)
+
(
∑
j
=
1
J
∏
k
=
1
j
S
k
)
-
1.
[0000] We next discuss the generation of the index at the sending eNB followed by the determination of the particular selection from the index at the receiving eNB. Towards this end, we define a set of offsets as follows:
[0000]
O
l
=
O
l
-
1
+
(
N
l
-
1
q
l
-
1
)
,
l
=
2
,
…
,
L
+
1
[0000] and O 1 =0. Further, we set O l =O l-1 +Π j=1 l-L-1 S j , l=L+2, . . . , L+J.
[0234] Generation of Index at Sending eNB
At the sending eNB, first identify the selection type l. If lε{1, . . . , L} then q l subbands are selected from N l total subbands. Let m 0 , . . . , m q l −1 be the selected subband indices that are ordered, i.e., m 0 <m 1 < . . . <m q l −1 and all lie in {1, . . . , N t }. Set
[0000]
R
=
O
l
+
∑
j
=
0
q
l
-
1
(
N
l
-
m
j
q
l
-
j
)
.
Else lε{L+1, . . . , L+J}. Let m 1 , . . . , m l-L denote the chosen subband indices, one from each of the first l−L bandwidth portions, and where m j ε{1 . . . , S j }, j=1, . . . l−L. Set R=O l +Π j=1 l-L m j −1.
[0238] Retrieving Subband Selection from Index at Receiving eNB
At the receiving eNB, find the greatest l such that O l ≦R. If lε{1, . . . , L} then q l subbands have been selected from N l total subbands. Let m 0 , . . . , m q l −1 be the ordered subband indices that need to be determined. Initialize a=1, r=R−O l . For k=0, . . . , q l −1 Do
b=a,
[0000]
Q
=
(
N
l
-
b
q
l
-
k
)
.
While Q>r Do: b=b+1 and
[0000]
Q
=
(
N
l
-
b
q
l
-
k
)
:
:EndWhile
m k =b, a=b+1, r=r−Q.
Else lε{L+1, . . . , L+J}. Let m 1 , . . . , m l-L denote the subband indices that need to be determined, one from each of the first l−L bandwidth portions, and where m j ε{1 . . . , S j }, j=1, . . . , l−L. Set r=R−O l , B=l−L and A=S 1 × . . . ×S B .
For k=1, . . . , B−1 Do
A=A/S k ,
[0000]
m
^
=
⌊
r
A
⌋
and m k ={circumflex over (m)}+1.
Update r=r−{circumflex over (m)}S k
m B =r+1
Embodiment E
[0250] E1 Introduction
[0251] We summarize the 3 options for subband definition, and provide enhancements for them, together with an enhancement for eRNTP (enhanced Relative Narrowband Tx Power).
[0252] E2 Summary of Solutions
[0253] General Notes:
All the following options allows eNB to“process” CQI (channel quality indication) values (implementation based manner) before sending over X2. Some of the main differentiators between the options are:
[0256] 1) Simplicity, if sending eNB implementation only sends “raw” CSI (Channel State Information)→Option A, C (albeit only with the respective enhancements)
[0257] 2) Flexibility, if sending eNB implementation processes CSI (e.g. combines or merges overlapping Periodic and Aperiodic reports)→Option B, C
[0258] Option A: Subband Index+Report Type
[0000]
TABLE E1
>>Subband CQI List
0 . . . <maxSubband>
>>>Subband CQI
M
9.2.cc
>>>Subband Index
O
INTEGER
Included in case of
(0 . . . 27, . . . )
UE selected
subband CQI
reporting.
>>> Report Type
O
ENUMERATED
Included in case of
(periodic,
UE selected
aperiodic, . . . )
subband CQI
reporting.
[0259] Notes for Option A:
Primary Motivation: Allows serving eNB to send CSI reports over X2 with as little processing as possible Description: The subband partitioning is fixed, based on the UE's CSI reporting configuration. The Report Type and Subtend Index IEs are used by the receiving eNB to derive the subband positions and their size and total number of subbands. The latter information is also important since it will enable receiving eNB to determine what the differential CQI conveyed for that subband means. This is because in aperiodic mode 3-0 (or 3-1) and aperiodic mode 2-0 (or 2-2) the same differential value can be mapped to different offsets, respectively. Thus, the only way the receiving eNB1 can deduce the right offset value to use is to utilize the fact that for the given system bandwidth (or given total number of PRBs (physical resource blocks) available at sending eNB2 (which is known or conveyed separately to eNB1)) the number of sub bands for which CQIs are reported is distinct under those two aperiodic modes, respectively. Another alternative is to convey the exact configured feedback mode (such as aperiodic 3-1 etc) under the Report type IE (information element). Allows sending “raw” CQI over X2, in a format similar to what is received from the UE (i.e. Subband Index) Allows sending both Periodic and Aperiodic reports in the same X2 message; in case of overlapping Aperiodic and Periodic CSI reports, the handling is left to receiving eNB implementation (e.g. merge, discard, etc). We note that sending two reports in the same message is beneficial since otherwise several reports may need to be dropped by the sending eNB in order to comply with the one report per X2 message constraint and the periodicity configured for the X2 messages.
[0264] However, a problem in sending both aperiodic and periodic subband reports together in the same X2 message as per the aforementioned structure, is that the associated reference wideband reports that are used to compute them can be different. In particular, the wideband rank indicators (RIs) that are determined by the UE under the configured aperiodic mode and the configured periodic mode can be different. Similarly, the wideband CQIs determined by the UE under the configured periodic mode and the configured aperiodic mode can be different. Furthermore, each subband CQI determined under the aperiodic mode is reported by the UE (over PUSCH (physical uplink shared channel)) as a differential value with respect to the corresponding wideband CQI. For example, suppose aperiodic feedback mode 2-2 and periodic feedback mode 2-1 are configured. Then, under the aperiodic mode 2-2 the UE will report one wideband CQI (per codeword) as well as one subband CQI (per codeword) for the selected best-M feedback as a differential value (using 2 bits) with respect to the wideband CQI corresponding to that codeword. On the other hand, under the periodic 2-1 mode the UE will report (over PUCCH (physical uplink control channel)) one wideband CQI (per codeword), with the wideband CQI of the second codeword being reported as a differential value with respect to the wideband CQI of the first one. In addition the UE will report one subband CQI for the first codeword and the second CQI as a differential value with respect to the subband CQI of the first one.
[0265] Therefore it becomes clear that we need to have separate sets of RIs and wideband CQIs in the X2 message whenever that message contains both aperiodic and periodic subband reports. If such separate sets of wideband components are not included then the receiving eNB will use the same wideband RI or CQI(s) for both aperiodic and periodic information. This defeats the purpose of conveying separate aperiodic and periodic subband reports in the same X2 message.
[0266] We propose an optimized structure in the following as a remedy to this issue.
[0000]
TABLE E2
IE/Group
IE type and
Semantics
Name
Presence
Range
reference
description
CSI Report per UE
1 . . . <maxUEReport>
>UE ID
M
BIT STRING
ID of the UE served
(SIZE(16))
by the cell in eNB 2 .
>CSI Report per
1 . . . <maxCSIProcess>
CSI Process
>>Report type per
0 . . . 1
CSI process
>>>Report Type
M
ENUMERATED
(periodic,
aperiodic, . . . )
>>>RI
M
INTEGER (1 . . . 8, . . . )
Defined in TS
36.213 [11].
>>>Wideband
M
9.2.bb
CQI
>>>Subband
0 . . . <maxSubband>
CQI List
>>>>Subband
M
9.2.cc
CQI
>>>>Subband
INTEGER (0 . . . 27, . . . )
Included in the case
Index
of UE selected
subband CQI
reporting.
Range bound
Explanation
maxUEReport
Maximum number of UE measurement reports. Value is
128.
maxCSIProcess
Maximum number of CSI processes. The value is 4.
maxSubband
Maximum number of subbands. The value can be 14 or 15
or 16 or 17 or 18 or 28
[0267] The value of 15 for the maxSubband is computed as 14+1, where 14 is the number of subbands in an aperiodic mode 3-0 or 3-1 assuming 110 DL (downlink) RBs (resource blocks) and 1 other subband is for periodic mode 2-0 or 2-1 assuming subband report for one bandwidth portion is allowed in the X2 message. Similarly, values 16,17,18 are computed assuming subband report for 2,3,4 bandwidth portions, respectively, are allowed in the same X2 message.
[0268] The same problem identified above can also arise when the sending eNB sends two different reports (corresponding to a configured periodic mode or corresponding to a configured aperiodic mode). The presented optimized structure addresses even such cases since it allows for two reporting types per CSI process of each UE. Each one of those two reporting types can be both periodic or both aperiodic.
[0269] In this context, we note that the value of maxSubband equal to 28 arises when we allow for two aperiodic reports, for example 28=14+14, where 14 is the number of subbands in an aperiodic mode 3-0 or 3-1 assuming 110 DL RBs.
[0270] Moreover, to provide further flexibility the range of the “Report type per CSI process” can be increased from two to a larger value such as 3 or 4 or 5.
[0271] 9.2.bb Wideband CQI
[0272] This IE indicates the Wideband CQI as defined in TS 36.213.
[0000]
TABLE E3
IE Type and
Semantics
IE/Group Name
Presence
Range
Reference
Description
Wideband absolute CQI
M
INTEGER (0 . . . 15, . . . )
Encoded in
Codeword 0
TS 36.213
[11].
CHOICE Wideband CQI
O
Codeword 1
>Wideband absolute CQI
M
INTEGER (0 . . . 15, . . . )
Encoded in
Codeword 1
TS 36.213
[11].
>Wideband differential CQI
M
INTEGER (0 . . . 7, . . .)
Encoded in
Codeword 1
TS 36.213
[11].
[0273] 9.2.cc Subband CQI
[0274] This IE indicates the Subband CQI as defined in TS 36.213.
[0000]
TABLE E4
IE Type and
Semantics
IE/Group Name
Presence
Range
Reference
Description
CHOICE Subband
M
CQI Codeword 0
>Subband
M
INTEGER (0 . . . 15, . . . )
Encoded in TS 36.213 [11].
absolute CQI
Codeword 0
>Subband
M
INTEGER (0 . . . 3, . . . )
Encoded in TS 36.213 [11].
differential CQI
Codeword 0
CHOICE Subband
O
CQI Codeword 1
>Subband
M
INTEGER (0 . . . 15, . . . )
Encoded in TS 36.213 [11].
absolute CQI
Codeword 1
>Subband
M
INTEGER (0 . . . 7, . . . )
Encoded in TS 36.213 [11].
differential CQI
Codeword 1
>Subband
M
INTEGER (0. . . 3, . . . )
Encoded in TS 36.213 [11].
differential CQI
Codeword 1
[0275] Other equivalent variations of the optimized structure are possible with the common theme being that a separate wideband component (comprising RI and wideband CQI(s)) is conveyed for the aperiodic and the periodic reports, respectively, and where the structure should allow the receiving eNB to unambiguously associate the periodic and aperiodic subband components with their respective wideband counterparts. Notice that under the optimized structure if only one of the aperiodic or periodic subband information is reported in the X2 message, it will include only the corresponding wideband information.
[0276] Notice also that under the aperiodic feedback modes (2-0 and 2-1) the UE reports common subband information for all the best-M subbands, thus in the structure presented above the sender eNB will repeat the same subband CQI for all the best-M indicated subbands. This repetition can be avoided by modifying the structure as follows.
[0277] The subband CQI IE is made optional with the understanding that if this IE is not present the CQI for that subband is taken to be the same as that of the subband (closest to it in frequency and of the same reporting type) with a lower index for which the CQI has been conveyed in that message, with the restriction that the latter CQI must have been indicated.
[0278] Option B: Subband Start+Subband Size
[0000]
TABLE E5
>>Subband CQI List
0 . . . <maxSubband>
>>>Subband CQI
M
9.2.cc
>>>Subband Start
O
INTEGER
Corresponds to the PRB
(2 . . . 109, . . . )
number of the first PRB in
a subband defined in TS
36.213 [11] for the system
bandwidth.lf this IE is not
present, the subband is
contiguous with the
previous subband in the
list, or starts with PRB 0 if
this is the first subband in
the list.
>>>Subband Size
M
ENUMERATED
Corresponds to a value of
(2, 3, 4, 6, 8, . . . )
subband size k defined in
TS 36.213 [11] for the
system bandwidth.
Ignored for the highest
frequency subband.
[0279] Notes for Option B:
Primary Motivation: Enables greater implementation flexibility for sending “processed” CQI in alignment with the RAN3 agreement that “the serving eNB can process CSI (implementation)”, particularly for the case where UE is configured for both Aperiodic and Periodic CSI reporting Description: The Subband Start and Subband Size IEs are used to explicitly indicate the subbands. The subbands are restricted to those defined for the system bandwidth N RB DL . Allows sending “raw” CQI over X2, but in a different format than used by the UE (i.e. Subband Start)
[0283] Allows sending both Periodic and Aperiodic reports in the same X2 message; in case of overlapping Aperiodic and Periodic CSI reports, the sending eNB can process (e.g. merge) according to implementation-specific algorithms
[0284] We note that in this structure given for option-B since only one set of wideband components are included, the sending eNB must harmonize RIs and wideband CQIs that are received from a periodic and aperiodic reports or two different periodic reports or two different aperiodic reports, respectively. In this context, using absolute value for the subband CQIs is particularly beneficial since then such CQIs can be directly used without matching them to any sideband reference.
[0285] As another optimization in this structure the Subband CQI IE can be made optional in which case the CQI for this subband is assumed to be the same as that of the last preceding subband for which a CQI is indicated. The CQI for the first sub band is always indicated. This optimization helps to avoid redundancies that can arise for instance in conveying best-M feedback as described before.
[0286] We note that here maximum number of subbands can be 28 (assuming 110 DL RBs and subband size of 4 under aperiodic mode 2-0 or 2-2).
[0287] Option C: Subband Index+Subband Size
[0000]
TABLE E6
>>Subband CQI List
0 . . .
<maxSubband>
>>>Subband CQI
M
9.2.cc
>>>Subband Index
O
INTEGER
Included in case of UE
(0 . . . 27, . . . )
selected subband CQI
reporting.
>>>Subband Size
M
ENUMERATED
Corresponds to a value
(2, 3, 4, 6, 8, . . . )
of subband size k defined
in TS 36.213 [11] for
the system bandwidth.
Ignored if the Subband
Index corresponds to the
highest frequency
subband.
[0288] Notes for Option C:
Description: The Subband Size IE is used by sending eNB to explicitly indicate the subband partitioning (rather than receiving eNB deriving the subband partitioning based on information about the UE's CSI reporting configuration). The PRB number of the first PRB in the subband is calculated as (Subband Index×Subband Size). Allows sending “raw” CQI over X2, in a format similar to what is received from the UE (i.e. Subband Index) Allows sending both Periodic and Aperiodic reports in the same X2 message; in case of overlapping Aperiodic and Periodic CSI reports, the sending eNB can process (e.g. merge) according to implementation-specific algorithms
[0292] If overlapping Aperiodic and Periodic CSI reports are received, then sending eNB can (as implementation option) “split” the Periodic subband into two Aperiodic subbands over X2. Assumption is that, according to subband definitions in TS 36.213, a Periodic subband is always composed of two Aperiodic subbands.
Example
[0293] N RB DL is 50, and eNB receives two CSI reports over Uu during a given interval: Aperiodic Mode 2-* for subband index 1 (subband size 3) and Periodic Mode 2-* for subband index 0 (subband size 6). Then, eNB has several options for sending the information over X2:
[0294] a) Send both reports over X2 and let receiving eNB decide how to handle
[0295] b) Select one of the two reports to send over X2 (e.g. the latest report)
[0296] c) Merge the Aperiodic and Periodic reports into two Aperiodic reports over X2 (subband index 0 and 1)
[0297] The observation made in option-A regarding the need to send separate wideband components in case both aperiodic and periodic reports are sent on the same X2 message also holds in this case.
[0298] Thus, we need to modify option-C as the following:
[0000]
TABLE E7
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per UE
1 . . .
<maxUEReport>
>UE ID
M
BIT STRING
ID of the UE served
(SIZE(16))
by the cell in eNB 2 .
>CSI Report per CSI
1 . . .
Process
<maxCSIProcess>
>> Refence type per
0 . . . 1
CSI process
>>>Reference Type
M
ENUMERATED
(periodic,
aperiodic, . . . )
>>>RI
M
INTEGER
Defined in TS
(1 . . . 8, . . . )
36.213 [11].
>>>Wideband CQI
M
9.2.bb
>>Subband CQI List
0 . . .
<maxSubband>
>>>Subband CQI
M
9.2.cc
>>>Subband Index
O
INTEGER
Included in case of
(0 . . . 27, . . . )
UE selected
subband CQI
reporting.
>>>Subband Size
M
ENUMERATED
Corresponds to a
(2, 3, 4, 6, 8, . . . )
value of subband
size k defined in TS
36.213 [11] for the
system bandwidth.
Ignored if the
Subband Index
corresponds to the
highest frequency
subband.
[0299] Other equivalent variations of the optimized structure are possible with the common theme being that a separate wideband component (comprising RI and wideband CQI(s)) is conveyed as a reference for the aperiodic and the periodic subband reports, respectively, and where the structure should allow the receiving eNB to unambiguously associate the periodic and aperiodic subband components with their respective wideband counterparts. Notice that under the optimized structure if only one of the aperiodic or periodic subband information is reported in the X2 message, it will include only the corresponding wideband information. Further, in case the structure includes merged CSI (where the merging or processing is done by the sender) then only one wideband component will be included and in this case all the subband CQIs will be conveyed as absolute CQIs (using 4 bits or 16 possibilities).
[0300] In this option the sending eNB must ensure that it uses the right number of subbands in its message when conveying the aperiodic CSI information. As described for option-A, doing so is important since it will enable receiving eNB to determine what the differential CQI conveyed for that subband means. This is because in aperiodic mode 3-0 (or 3-1) and aperiodic mode 2-0 (or 2-2) the same differential value can be mapped to different offsets, respectively. Thus, the only way the receiving eNB1 can deduce the right offset value to use is to utilize the fact that for the given system bandwidth (or given total number of PRBs available at sending eNB2 (which is known or conveyed separately to eNB1)) the number of sub bands for which CQIs are reported is distinct under those two aperiodic modes, respectively.
[0301] Option C′: Subband Index+Subband Size
[0000]
TABLE E8
>>Subband
M
ENUMERATED
Corresponds to a
Size
(2, 3, 4, 6, 8, . . . )
value of subband
size k defined in TS
36.213 [11]for the
system bandwidth.
>>Subband
0 . . .
CQI List
<maxSubband>
>>>Subband
M
9.2.cc
CQI
>>>Subband
O
INTEGER
Included in case
Index
(0 . . . 27, . . . )
of UE selected
subband
CQI reporting.
[0302] Notes for Option C′:
Description: Like Option C, but the Subband Size is fixed for all subbands. Here maximum number of subbands can be 28 (assuming 110 DL RBs and subband size of 4 under aperiodic mode 2-0 or 2-2).
[0304] eRNTP Enhancements.
[0305] We provide an eRNTP version which allows the sender eNB to seamlessly convey either explicitly convey the applied power level (relative to one or more specified thresholds) or to convey whether a resource will be interference protected or not. We note that a resource can be interference protected by multiple methods which include lower power or by using an appropriate beam forming vector etc.
[0000]
TABLE E9
IE type and
Semantics
Assigned
IE/Group Name
Presence
Range
reference
description
Criticality
Criticality
RNTP per PRB
M
BIT
Each position in
—
—
STRING
the bitmap
(6 . . . 110, . . . )
represents a n PRB
value (i.e. first
bit = PRB 0 and so
on), for which the
bit value
represents RNTP
(n PRB ), defined in
TS 36.213 [11].
Value 0 indicates
“Tx not
exceeding RNTP
threshold”.
Value 1 indicates
“no promise on
the Tx power is
given”.
This IE is ignored
if the Enhanced
RNTP IE is
present.
RNTP Threshold
O
ENUMERATED
RNTP threshold is
—
—
(−∞,
defined in TS
−11, −10, −9,
36.213 [11]. This
−8, −7, −6, −5,
IE is always
−4, −3, −2, −1,
present if the
0, 1, 2, 3, . . . )
Enhanced RNTP
IE is not present.
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . . )
antenna ports for
Antenna Ports
cell-specific
reference
signals) defined
in TS 36.211 [10]
P_B
M
INTEGER
P B is defined in
—
—
(0 . . . 3, . . . )
TS 36.213 [11].
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . . )
Predicted
Impact
Number Of
Occupied
PDCCH OFDM
Symbols (see TS
36.211 [10]).
Value 0 means
“no prediction is
available”.
Enhanced RNTP
O
BIT
Each position in
IE
STRING
the bitmap
(6 . . . 4400, . . . )
represents a
PRB in a
subframe. If the
RNTP Threshold
IE is present then
the value “1”
indicates ‘no
promise on the
Tx power is
given’ and value
“0” indicates ‘Tx
not exceeding
RNTP threshold.’
If the
RNTP Threshold
IE is not present
then value “1”
indicates
‘resource with no
utilization
constraints’ and
value “0”
indicates
‘interference
protected
resource.’
The first bit
corresponds to
PRB 0 of the first
subframe for
which the
Enhanced RNTP
IE is valid, the
second bit
corresponds to
PRB 1 of the first
subframe for
which the
Enhanced RNTP
IE is valid, and so
on.
The length of the
bit string is an
integer
(maximum 40)
multiple of N RB DL .
N RB DL is defined in
TS 36.211 [10].
The bit string
may span across
multiple
contiguous
subframes.
The pattern
across
contiguous
subframes
formed by
Enhanced RNTP
IE is continuously
repeated.
Enhanced
0 . . . 1
RNTP IE start
time
>Starting SFN
M
INTEGER
SFN of the radio
(0 . . . 1023, . . . )
frame containing
the first subframe
when the
Enhanced RNTP
IE is valid.
>Starting
M
INTEGER
Subframe number,
Subframe Index
(0 . . . 9, . . . )
within the radio
frame indicated by
the Start SFN IE,
of the first
subframe when the
Enhanced RNTP
IE is valid.
Embodiment F
[0306] F1. Introduction
[0307] In this document we discuss some issues with subband indexing schemes and then present our preference in a proposal.
[0308] F2. Discussion
[0309] F2.1 Conveying Both Periodic and Aperiodic Reports
[0310] A desirable feature that should be supported by a CSI signaling scheme is the exchange of both periodic and aperiodic CSI reports in the same X2 message, possibly in a combined (or merged) form. In the absence of this feature, i.e., when the sending eNB is forced to choose either the periodic or the aperiodic CSI report obtained under a CSI process of some user, the sending eNB will have to drop available CSI reports. This would be unfortunate given that precious over-the-air signaling resources have already been spent in acquiring these reports and these reports can together convey more CSI that either individual one.
[0311] Then, a problem that needs to be overcome in order to send both aperiodic and periodic subband reports together in the same X2 message, is described next. In particular, the associated reference wideband reports that are used to compute the constituent subband parts of the aperiodic and periodic CSI reports, respectively, can be different. Indeed, the wideband rank indicators (RIs) that are determined by the UE under the configured aperiodic mode and the configured periodic mode can be different. Similarly, the wideband CQIs determined by the UE under the configured periodic mode and the configured aperiodic mode are also more likely to be different. Furthermore, each subband CQI determined by the UE under the configured mode can be reported by it as a differential value with respect to a corresponding reference CQI. For example, suppose aperiodic feedback mode 2-2 and periodic feedback mode 2-1 are configured. Then, under the aperiodic mode 2-2 the UE will report (over PUSCH) one wideband CQI (per codeword) as well as one subband CQI (per codeword) for the selected best-M feedback as a differential value (using 2 bits) with respect to the wideband CQI corresponding to that codeword. On the other hand, under the periodic 2-1 mode the UE will report (over PUCCH) one wideband CQI (per codeword), with the wideband CQI of the second codeword being reported as a differential value with respect to the wideband CQI of the first one. In addition the UE will report one subband CQI for the first codeword and the second codeword subband CQI as a differential value with respect to the subband CQI of the first one.
[0312] Therefore it becomes clear that we have to alternatives to overcome this issue:
[0313] Alternative-1: Provision to include
[0314] two separate sets of RIs and wideband CQIs in the X2 message whenever that message contains both aperiodic and periodic subband reports. This will allow simple forwarding of both aperiodic and periodic reports in the same X2 message. In this context, we note that a structure which does not provide for including two separate sets of wideband components, forces the sending eNB to merge the wideband components and use a common reference for both aperiodic and periodic subband information. This defeats the purpose of conveying separate aperiodic and periodic subband reports in the same X2 message. Another issue in including the report type IE (specifying periodic or aperiodic report) within the list of subbands, is that ambiguity can be introduced when certain aperiodic and periodic reports are combined.
[0315] Alternative-2: Always merge separate sets of wideband components into one wideband component that will also be used as a common reference. In this case it is logical to merge the respective subband information as well, and upon doing so there is no need to indicate the type of the subband CSI report. However, this view prevents simple forwarding of both aperiodic and periodic reports in the same X2 message.
[0316] In order to obtain the merits of both the aforementioned alternatives, we propose a simple structure. This structure is presented in three versions, with the second and third ones being more bit-efficient version of the first.
[0317] The benefits of this proposal are as follows:
[0318] It allows for simple forwarding of both aperiodic and periodic reports in the same X2 message. In fact it allows for forwarding of multiple aggregated aperiodic or periodic CSI reports (from a UE under a CSI process) or their combinations in the same X2 message.
[0319] The parameter N RB DL together with the conveyed subband size IE defines the subband partition, which corresponds to one of those defined in TS36.213.
[0320] It also allows for merging an aperiodic and a periodic report (or merging combinations of multiple periodic and/or multiple aperiodic CSI reports) without introducing any new subband definitions. This is because for a given total number of RBs (or PRBs), N RB DL , the subband size in aperiodic mode 2-* is exactly half of that of the aperiodic mode 3-* as well as periodic mode 2-*. Thus, in order to combine such reports we can use the subbands defined by the smaller subband size and convey (possibly processed) CQIs for them.
[0321] Other implementation based processing of the short-term CSI is also supported.
[0322] The first version is relatively straightforward. Two of its features are however worth pointing out:
[0323] For each CSI process we can convey up-to maxReferenceType reports. The Reference Type IE can be ENUMERATED for instance as periodic or aperiodic. Alternatively, the Reference Type IE can simply be dropped.
[0324] The subband CQIs are conveyed sequentially in the increasing order of subband indices. Then, in case the subband CQI IE for a subband is not conveyed, the receiving eNB must use the CQI conveyed for the last preceding subband. The CQI for the first subband must always be included. This feature can significantly save overhead by avoiding redundancy. Note that when a UE is configured in the aperiodic mode 2-*, it selects and reports indices for M out of N subbands. However, only one CQI (per codeword) is reported by it for all the M selected subbands. Therefore, it is beneficial that redundancy is avoided in reporting such CQIs.
[0325] The Subband Index IE is optional. In case this IE is not included then the subband CQI information for each one of the total number of subbands is conveyed. Recall that the parameter N RB DL together with the conveyed subband size IE defines the subband partition, thereby conveying the total number of subbands N.
[0326] We now consider a more bit efficient second version in which the sub band selection is conveyed by means of a combinatorial index.
[0327] Here, under each Reference Type IE, the parameter N RB DL together with the conveyed subband size IE defines the subband partition, thereby conveying the total number of subbands N. Also the number of subbands for which subband CQI is conveyed, M, is determined by the size of the Subband CQI List IE.
[0328] The combinatorial index, r, is defined based on TS36.213 (section 7.2.1) as follows:
[0329] The positions of the M selected subbands is conveyed using a combinatorial index r defined as
[0000]
r
=
∑
i
=
0
M
-
1
〈
N
-
s
i
M
-
i
〉
[0000] where N denotes the total number of subbands and the set {s i } i=0 M-1 , (1≧s i ≧N, s i >s i+1 ) contains the M sorted subband indices and
[0000]
〈
x
y
〉
=
{
(
x
y
)
x
≥
y
0
x
<
y
[0000] is the extended binomial coefficient, resulting in unique label
[0000]
r
∈
{
0
,
…
,
(
N
M
)
-
1
}
.
[0330] To illustrate, consider first the case when N RB DL =110 and the Reference Type IE is set to be aperiodic. Then, we have two possibilities for subband selection. The first one is when the configured mode is 2-* in which case the subband size is 4 so that N=28 and here M=6. On the other hand, for aperiodic mode 3-* the subband size is 8 so that N=14 and here M=14. Similar argument applies to all other modes as well. It is also apparent that there is significant flexibility in aggregating several different reports under a Reference Type, as long as the subband partition is a valid one, i.e., corresponds to a one defined in TS36.213. Since the maximum value of N=28 (when N RB DL =110 and subband size is 4) we represent the combinatorial index using a bit string of length 26. This allows us to convey any possible selection choice of subbands from the maximum of 28 subbands.
[0331] Next, we consider the third version in which the sub band selection is again conveyed by means of a combinatorial index. This version can be somewhat more restrictive compared to the second version but can also be more bit efficient. Here, the number of selected subbands and their size, in addition to their positions or indices, are also indicated by the combinatorial index.
[0332] Consider first the case when the Report Type IE is set to be aperiodic. Then, we have two possibilities for subband selection. The first one is when the configured mode is 2-* in which case the combinatorial index, r, is defined based on TS36.213 (section 7.2.1) as follows:
[0333] The positions of the M UE selected subbands is conveyed using a combinatorial index r defined as
[0000]
r
=
∑
i
=
0
M
-
1
〈
N
-
s
i
M
-
i
〉
[0000] where N denotes the number of subbands and the set {s i } i=0 M-1 , (1≧s i ≧N, s i >s i+1 ) contains the M sorted subband indices and
[0000]
〈
x
y
〉
=
{
(
x
y
)
x
≥
y
0
x
<
y
[0000] is the extended binomial coefficient, resulting in unique label
[0000]
r
∈
{
0
,
…
,
(
N
M
)
-
1
}
.
[0334] One additional possibility must be included to cover the case when the configured mode is 3-* in which case CQIs for all subbands have to be conveyed. We can choose r=−1 for this purpose. Then, notice that the combinatorial index, r, along with the parameter, N RB DL , together convey the total number of subbands, N, and the number of selected subbands, M, as well as the size of each subband and their positions or indices.
[0335] Consider next the case when the Report Type IE is set to be periodic. We consider the mode 2-* that is the only mode under which the subband information is reported. Here the user reports CSI for one selected subband from each one of the J bandwidth parts (or portions) sequentially over successive reporting instances. Therefore, depending on the periodicities configured for the X2 CSI exchange and the over-the-air reports, the sending eNB can have subband reports for up-to J subbands. Notice that since the user must report the information for each subband sequentially, no bandwidth part indicator is defined in TS36.213. We adopt the same approach and enforce that the subband CSI for all available bandwidth parts must be reported in the same X2 message. This nested structure will make the X2 message self-contained and avoid the need for a separate bandwidth part indicator.
[0336] Accordingly, letting N1, N2, . . . , NJ, denote the number of subbands in each of the J bandwidth parts, the combinatorial index must cover for N1 possibilities for the subband selection from the first bandwidth part, N1*N2 possibilities for the subband selections together from the first and second bandwidth parts, and so on till N1*N2* . . . NJ possibilities for the subband selections together from all the J bandwidth parts.
[0337] F3. Conclusion
[0338] We discussed the necessary X2 message to support CSI exchange for inter-eNB CoMP and presented our views on subband indexing along with corresponding proposals.
[0339] 9.1.2.14 Resource Status Update
[0340] This message is sent by eNB 2 to neighbouring eNB 1 to report the results of the requested measurements.
[0341] Direction: eNB 2 →eNB 1 .
[0342] 9.2.aa UE-CSI Report (Version-1)
[0343] This IE provides UE-CSI information for a set of UEs served by eNB 2 .
[0000]
TABLE F1
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per UE
1 . . .
<maxUEReport>
>UE ID
M
BIT STRING
ID of the UE
(SIZE(16))
served by the cell
in eNB 2 .
>CSI Report per CSI
1 . . .
Process
<maxCSIProcess>
>> UE-CSI process
M
FFS
FFS
CSI process
Configuration index
configuration
information.
>> Reference type per
1 . . .
CSI process
<maxReferenceTypes>
>>>Reference Type
M
ENUMERATED
>>>RI
M
INTEGER
Defined in TS
(1 . . . 8, . . . )
36.213 [11].
>>>Wideband CQI
M
9.2.bb
>>>Subband Size
M
ENUMERATED
Corresponds to a
(2, 3, 4, 6, 8, . . . )
value of subband
size k defined in
TS 36.213 [11]for
the system
bandwidth.
Ignored if the
Subband Index
corresponds to the
highest frequency
subband.
>>>Subband CQI List
1 . . .
<maxSubband>
>>>>Subband CQI
O
9.2.cc
If this IE is not
present, the CQI is
identical to the one
provided for the
last preceding
subband. This IE is
always present for
the first subband in
the list.
>>>>Subband Index
O
INTEGER
(0 . . . 27, . . . )
Range bound
Explanation
maxUEReport
Maximum number of UE measurement reports. Value is 128.
maxCSIProcess
Maximum number of CSI processes. The value is 4.
maxReferenceTypes
Maximum types of of CSI reports. The value is 2.
maxSubband
Maximum number of subbands. The value is 28
[0344] Alternatively, the value of maxReferenceTypes can be 3 or 4.
[0345] UE-CSI Report (Version-2)
[0000]
TABLE F2
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per UE
1 . . .
<maxUEReport>
>UE ID
M
BIT STRING
ID of the UE
(SIZE(16))
served by the cell
in eNB 2 .
>CSI Report per CSI
1 . . .
Process
<maxCSIProcess>
>> UE-CSI process
M
FFS
FFS
CSI process
Configuration index
configuration
information.
>> Reference type per
1 . . .
CSI process
<maxReferenceTypes>
>>>Reference Type
M
ENUMERATED
>>>RI
M
INTEGER
Defined in TS
(1 . . . 8, . . . )
36.213 [11].
>>>Wideband CQI
M
9.2.bb
>>> Subband Size
M
ENUMERATED
Corresponds to a
(2, 3, 4, 6, 8, . . . )
value of subband
size k defined in
TS 36.213 [11] for
the system
bandwidth.
Ignored if the
Subband Index
corresponds to
the highest
frequency
subband.
>>> combinatorial
M
BITSTRING
As defined in
index
(SIZE(26))
TS36.213
(section 7.2.1).
The indices of the
subbands in the
list are indicated
by this
combinatorial
index. Subband
CQIs are sorted
in the order of
increasing
frequency
(increasing
subband indices).
>>>Subband CQI List
1 . . .
<maxSubband>
>>>>Subband CQI
O
9.2.cc
If this IE is not
present, the CQI
is identical to the
one provided for
the last preceding
subband. This IE
is always present
for the first
subband in the
list.
Range bound
Explanation
maxUEReport
Maximum number of UE measurement reports. Value is 128.
maxCSIProcess
Maximum number of CSI processes. The value is 4.
maxReferenceTypes
Maximum types of of CSI reports. The value is 2.
maxSubband
Maximum number of subbands. The value is 28
[0346] Version-3:
[0000]
TABLE F3
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per UE
1 . . .
<maxUEReport>
>UE ID
M
BIT STRING
ID of the UE
(SIZE(16))
served by the
cell in eNB 2 .
>CSI Report per CSI
1 . . .
Process
<maxCSIProcess>
>> UE-CSI process
M
FFS
FFS
CSI process
Configuration index
configuration
information.
>> Reference type per
1 . . .
CSI process
<maxReferenceTypes>
>>>Reference Type
M
ENUMERATED
>>>RI
M
INTEGER
Defined in TS
(1 . . . 8, . . . )
36.213 [11].
>>>Wideband CQI
M
9.2.bb
>>> combinatorial
M
As defined in
index
TS36.213
(section 7.2.1).
The number of
subbands in the
list, their indices,
as well their
size, are
indicated by this
combinatorial
index. Subband
CQIs are sorted
in the order of
increasing
frequency
(increasing
subband
indices).
>>>Subband CQI List
1 . . .
<maxSubband>
>>>>Subband CQI
O
9.2.cc
If this IE is not
present, the CQI
is identical to the
one provided for
the last
preceding
subband. This IE
is always
present for the
first subband in
the list.
Range bound
Explanation
maxUEReport
Maximum number of UE measurement reports. Value is 128.
maxCSlProcess
Maximum number of CSI processes. The value is 4.
maxReferenceTypes
Maximum types of of CSI reports. The value is 2.
maxSubband
Maximum number of subbands. The value is 28
Embodiment G
[0347] G1. Introduction
[0348] In order to meet the objectives of the Inter eNB CoMP WI it was agreed to extend the RNTP IE to include transmission power level indication per time frequency resources spanning across multiple subframes.
[0349] In the following, we provide our views on content of this message, as well as proposals.
[0350] G2. Discussion
[0351] G2.1 eRNTP Exchange
[0352] One concern that was raised during the discussions in RAN3#87 bis was on the semantic description of the enhanced RNTP IE whether it is suitable to use the phrase “TX power not exceeding a threshold”. This is because certain implementations can achieve “interference protection” via other means such as beam-forming or beam-steering. We believe that even for such implementations, there is a notion of a threshold on effective radiated power from which the receiving eNB can deduce if a resource would be interference protected or not. We note that effective radiated power is a commonly used metric (terminology) which captures the effect of several relevant parameters such as transmit power, antenna gain, directivity, etc. Consequently, it is suitable to have an explicit threshold associated with the enhanced RNTP which indicates the “action” by the sender. We note that it is possible for sender eNB to send different eRNTP messages to different receiving eNBs to convey the potentially different net impacts of its adopted beam patterns and transmit powers on those receiving eNBs.
[0353] Accordingly, our preference is to retain the baseline agreement from the last meeting with a modification in the semantic description to use the phrase “Effective radiated TX power” instead of “TX power”. This will also accommodate newer implementations that rely on spatial/antenna domain processing to achieve interference mitigation.
[0354] We present two proposals. The first one is a more bit-efficient version of the BL agreement (albeit including the aforementioned modified semantic description). It exploits that fact an RNTP IE indicating transmit power levels for the first subframe (subframe #0) must always conveyed. Then, instead of ignoring this IE in the case when the enhanced RNTP IE is included, we can still use it to convey the per-PRB power level information for the first subframe. Moreover, instead of providing per-PRB power level information for each subsequent subframe in the enhanced RNTP IE, we can optionally adopt a more efficient representation in which such information for a subframe is conveyed only if it differs from that of the preceding one.
[0355] The second proposal is based on multiple thresholds, where we note that certain implementation can extract gains from such finer power level indication. The point here is that since the choice ‘11’ already indicates no promise on the effective radiated transmit power level (which covers the case of transmit power being arbitrarily high) we can use three thresholds (instead of two), since there is no need to convey that the power level is greater than HPTH (as this is subsumed by ‘11’).
[0356] G3. Conclusion
[0357] We discussed the necessary X2 message to support eRNTP exchange for inter-eNB CoMP and presented corresponding proposals.
[0358] Proposal:
[0359] 9.2.19 Relative Narrowband Tx Power (RNTP)
[0360] This IE provides an indication on DL power restriction per PRB in a cell and other information needed by a neighbour eNB for interference aware scheduling.
[0000]
TABLE G1
IE type and
IE/Group Name
Presence
Range
reference
Semantics description
RNTP Per PRB
M
BIT STRING
Each position in the bitmap
(6 . . . 110, . . . )
represents a n PRB value (i.e.
first bit = PRB 0 and so on),
for which the bit value
represents RNTP (n PRB ),
defined in TS 36.213 [11].
Value 0 indicates
“Effective radiated Tx
power not exceeding RNTP
threshold”.
Value 1 indicates “no
promise on the Effective
radiated Tx power is
given”. This IE is used to
indicate DL power
restriction per PRB for the
first subframe.
RNTP Threshold
M
ENUMERATED
RNTP threshold is defined in
(−∞, −11, −10, −9, −8,
TS 36.213 [11].
−7, −6, −5, −4, −3, −2,
−1, 0, 1, 2, 3, . . . )
Number Of
M
ENUMERATED
P (number of antenna ports
Cell-specific
(1, 2, 4, . . . )
for cell-specific reference
Antenna Ports
signals) defined in TS
36.211 [10]
P_B
M
INTEGER
PB is defined in TS 36.213
(0 . . . 3, . . . )
[11].
PDCCH
M
INTEGER
Measured by Predicted
Interference
(0 . . . 4, . . . )
Number Of Occupied
Impact
PDCCH OFDM Symbols
(see TS 36.211 [10]).
Value 0 means “no
prediction is available”.
Enhanced
O
BIT STRING
Each position in the bitmap
RNTP
(6 . . . 4290, . . . )
represents a PRB in a
subframe, for which value
“indicates ‘no promise
on the Effective radiated Tx
power is given’ and value
“0” indicates Effective
radiated Tx power not
exceeding RNTP
threshold.’
The first bit corresponds to
PRB 0 of the first subframe
for which the IE is valid,
the second bit corresponds
to PRB 1 of the first
subframe for which the IE
is valid, and so on.
The length of the bit string
is an integer (maximum 39)
multiple of N RB DL which is
defined in TS 36.211 [10].
The bit string may span
across multiple contiguous
subframes.
The pattern across
contiguous subframes
(formed by RNTP IE and
Enhanced RNTP IE) is
continuously repeated
[0000]
TABLE G2
IE/Group
IE type and
Semantics
Assigned
Name
Presence
Range
reference
description
Criticality
Criticality
RNTP Per PRB
M
BIT STRING
Each position in
—
—
(6 . . . 110, . . . )
the bitmap
represents a n PRB
value (i.e. first
bit = PRB 0 and
so on), for which
the bit value
represents RNTP
(n PRB ), defined
in TS 36.213
[11].
Value 0
indicates
“Effective
radiated Tx
power not
exceeding
RNTP
threshold”.
Value 1
indicates “no
promise on the
Effective
radiated Tx
power is
given”. This IE
is ignored when
the enhanced
RNTP IE is
included.
RNTP
M
ENUMERATED
RNTP threshold is
—
—
Threshold
(−∞, −11,
defined in TS
−10, −9, −8, −7,
36.213
−6, −5, −4, −3,
[11]. This IE is
−2, −1, 0, 1, 2,
ignored when
3, . . . )
the enhanced
RNTP IE is
included.
Number Of
M
ENUMERATED
P (number of
—
—
Cell-specific
(1, 2, 4, . . . )
antenna ports for
Antenna Ports
cell-specific
reference
signals) defined
in TS 36.211
[10]
PDCCH
M
INTEGER
Measured by
—
—
Interference
(0 . . . 4, . . . )
Predicted
Impact
Number Of
Occupied
PDCCH OFDM
Symbols (see TS
36.211 [10]).
Value 0 means
“no prediction is
available”.
Enhanced
O
BIT STRING
Each position
—
—
RNTP
(12, . . . 8800, . . . )
in the bitmap
represents a
PRB in a
subframe, for
which the value
“xx” indicates
how the
Effective
radiated
transmission
power in a
resource block
is mapped
relative to the
three power
thresholds:
00—Effective
radiated TX
power level not
exceeding the
LPTH
01—Effective
radiated TX
power level
between LPTH
and MPTH;
10—Effective
radiated TX
power level
between
MPTH and
HPTH;
11—no
promise on the
Effective
radiated TX
power is given.
The first 2 bits
correspond to
PRB 0 of the
first subframe
for which the IE
is valid, the
following 2 bits
correspond to
PRB 1 of the
first subframe
for which the IE
is valid, and so
on.
The bit string
may span
across multiple
contiguous
subframes.
The length of
the bit string is
an integer
(maximum 40)
multiple of,
N RB DL which is
defined in TS
36.211 [10].
The Enhanced
RNTP pattern
is continuously
repeated
> Enhanced
RNTP
thresholds
>>LPTH (Low
M
ENUMERATED
Lower RNTP
—
—
Power
(−∞, −11,
power
Threshold)
−10, −9 −8
threshold,
−7, −6, −5, −4,
using the
−3, −2, −1, 0,
RNTP threshold
1, 2, 3, . . . )
defined in TS
36.213 [11].
>>MPTH
M
ENUMERATED
Medium RNTP
(Medium
(−∞, −11,
power
Power
−10, −9, −8,
threshold,
Threshold)
−7, −6, −5, −4,
using the
−3, −2, −1, 0,
RNTP threshold
1, 2, 3, . . . )
defined in TS
36.213 [11].
>>HPTH
M
ENUMERATED
Higher RNTP
(High Power
(−∞, −11,
power
Threshold)
−10, −9, −8,
threshold,
−7, −6, −5, −4,
using the
−3, −2, −1, 0,
RNTP threshold
1, 2, 3, . . . )
defined in TS
36.213 [11].
[0361] Alternative structure for subband indexing:
[0000]
TABLE G3
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per UE
1 . . .
<maxUEReport>
>UE ID
M
BIT STRING
ID of the UE
(SIZE(16))
served by the cell
in eNB 2 .
>CSI Report per CSI
1 . . .
Process
<maxCSIProcess>
>> UE-CSI process
M
FFS
FFS
CSI process
Configuration index
configuration
information.
>> Reference type per
1 . . .
CSI process
<maxReferenceTypes>
>>>Reference Type
M
ENUMERATED
>>>RI
M
INTEGER
Defined in TS
(1 . . . 8, . . . )
36.213 [11].
>>>Wideband CQI
M
9.2.bb
>>>Subband CQI List
0 . . .
<maxSubband>
>>>>Subband CQI
O
9.2.cc
If this IE is not
present, the CQI is
identical to the one
provided for the
last preceding
subband. This IE
is always present
for the first
subband in the list.
>>>>Subband Start
O
INTEGER
Corresponds to
(2 . . . 109, . . . )
the PRB number
of the first PRB in
a subband defined
in TS 36.213 [11]
for the system
bandwidth.lf this IE
is not present, the
subband is
contiguous with
the previous
subband in the list,
or starts with PRB
0 if this is the first
subband in the list.
>>>>Subband Size
O
ENUMERATED
Corresponds to a
(2, 3, 4, 6, 8, . . . )
value of subband
size k defined in
TS 36.213 [11]for
the system
bandwidth.
Ignored for the
highest frequency
subband. If this IE
is not present, the
size is identical to
the one provided
for the last
preceding
subband. This IE
is always present
for the first
subband in the list.
Embodiment H
[0362] H1. Introduction
[0363] In RAN3#88, after fruitful discussions on the exchange of CSI, a subband indexing scheme has been selected in the baseline CR (change request) [4]. In this document we identify some corrections that can be made and present them in a proposal.
[0364] H2. Discussion
[0365] A desirable feature that should be supported by a CSI signaling scheme is the exchange of both periodic and aperiodic CSI reports in the same X2 message. In the absence of this feature, i.e., when the sending eNB is forced to choose either the periodic or the aperiodic CSI report obtained under a CSI process of some user, the sending eNB will have to drop available CSI reports. This would be unfortunate given that precious over-the-air signaling resources have already been spent in acquiring these reports and that these reports can together convey more CSI that either individual one.
[0366] Accepting this view an indexing scheme to enable this feature has been selected in [4].
[0367] We identify two corrections and an improvement that can be made to the selected scheme:
[0368] Correction: Changing the subband index range to (0, . . . 27, . . . } from {0, . . . , 13, . . . }:
[0369] A benefit that can be obtained from the subband indexing scheme of [4] is the simple forwarding of both aperiodic and periodic CSI reports in the same X2 message. Notice that the maxSubband value is 14 and the subband index range is defined to be {0, . . . , 13, . . . }. This choice allows for simple forwarding with any configured periodic mode and when the configured a-periodic mode is 3-*. This is because in these cases the maximum number of subband reports is 14 and the index range spans {0, . . . , 13}, consistent with the agreed choice.
[0370] However, this choice will not allow the same X2 message to include aperiodic CSI report configured with feedback mode 2-* and periodic CSI report configured under any mode. This is because under aperiodic mode 2-*, when the total number of PRBs in the downlink is N RB DL =110, the subband size is k=4 and the number of UE selected subbands is M=6 (Table 7.2.1.5 in TS36.213). Thus, we have N=28 subbands (110=4*27+2 \) and the UE is free to select any 6 out of these 28 subbands as its preferred ones. Consequently, the subband index identifying each UE selected subband must belong to the set {0, . . . , 27}. . . .
[0371] Consequently, one of the two CSI process items should have a subband index range of {0, . . . , 27}. For simplicity we suggest a common subband index range of {0, . . . , 27} for both CSI process items. A slightly more efficient alternative could be where one of the two CSI process items (say CSI process item 1) has index range {0, . . . , 27} whereas the other one has index range {0, . . . , 13}.
[0372] 2) Correction: Changing the semantic description to reflect that a different RI and CQI combination can be reported for each one of the two CSI process items under the same CSI process.
[0373] 3) Improvement: Making the subband CQI IE optional with a clarification in the semantic description.
[0374] The subband CQIs are conveyed sequentially in the increasing order of subband indices. Then, in case the subband CQI IE for a subband is not conveyed, the receiving eNB must use the CQI conveyed for the last preceding subband. The CQI for the first subband must always be included. This approach can significantly save overhead by avoiding redundancy. Note that when a UE is configured in the aperiodic mode 2-*, it selects and reports indices for M out of N subbands. However, only one CQI (per codeword) is reported by it for all the M selected subbands. Therefore, it is beneficial that redundancy is avoided in reporting such CQIs in the X2 message as well.
[0375] H3. Conclusion
[0376] We identified three improvements that can be made in the UE-CSI IE and present them in a proposal.
[0377] 9.2.aa UE-CSI Report
[0378] This IE provides CSI reports of UEs served by the cell for which the information is provided.
[0000]
TABLE H1
IE type and
Semantics
IE/Group Name
Presence
Range
reference
description
CSI Report per Cell
1 . . .
<maxUEReport>
>UE ID
M
BIT STRING
ID assigned by
(SIZE(16))
eNB2 for the UE.
>CSI Report per CSI
1 . . .
Process
<maxCSIProcess>
>>CSI Process
M
FFS
Configuration Index
>>CSI Report per
1 . . .
CSI Process Item
<maxCSIReport>
>>>RI
M
INTEGER
The RI
(1 . . . 8, . . . )
corresponding to the
CQI being reported
for this CSI process
Item. Value defined
in TS 36.213 [11].
>>>Wideband CQI
M
9.2.bb
>>>Subband Size
M
ENUMERATED
Corresponds to a
(2, 3, 4, 6, 8, . . . )
value of subband
size k defined in TS
36.213 [11]for the
system bandwidth
N RB DL .
>>>Subband CQI
0 . . .
List
<maxSubband>
>>>>Subband
O
9.2.cc
If this IE is not
CQI
present, the CQI is
identical to the one
provided for the last
preceding subband.
This IE is always
present for the first
subband in the list.
>>>Subband
M
INTEGER
Index
(0 . . . 27, . . . )
Range bound
Explanation
maxUEReport
Maximum number of UE. Value is 128.
maxCSIProcess
Maximum number of CSI processes per UE. The value is 4.
maxCSIReport
Maximum number of CSI Reports per CSI Process. The value is 2.
maxSubband
Maximum number of subbands. The value is 14.
[0379] The foregoing is to be understood as being in every respect illustrative and exemplary, but not restrictive, and the scope of the invention disclosed herein is not to be determined from the Detailed Description, but rather from the claims as interpreted according to the full breadth permitted by the patent laws. It is to be understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that those skilled in the art may implement various modifications without departing from the scope and spirit of the invention. Those skilled in the art could implement various other feature combinations without departing from the scope and spirit of the invention. | In a wireless communications system including a first base station and a second base station, a wireless communications method implemented in the first base station supporting coordinated multi-point transmission and reception (CoMP) is disclosed. The wireless communications method comprises receiving, from the second base station, a user equipment (UE) identification (ID) for a UE in a reference signal received power (RSRP) report, and using the UE ID to link the RSRP report with another measurement result for the UE. Other methods, systems, and apparatuses also are disclosed. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit under 35 U.S.C. 119(e) from U.S. Provisional Application No. 60/192,887 filed on Mar. 29, 2000.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention generally relates to a driver circuit for a variety of symmetric load systems. The invention specifically describes a power circuit based on a balanced capacitive loading method wherein the load itself acts as an energy storage element in the energy balance system. In preferred embodiments, the circuit redirects power from a near lossless load to either another load of the same type or to a capacitively equal inactive element. At any given time, a portion of the symmetric load system acts as an actuator and the remaining pure capacitive portion functions similar to a power bypass capacitor.
[0005] 2. Related Arts
[0006] A large class of active control devices incorporate small, high-force transductive mechanisms to develop mechanical force. Electrostriction mechanisms develop mechanical force by the interaction of electric fields within the transducer. Magnetostriction mechanisms develop mechanical force by the interaction of magnetic fields within the transducer. Transductive mechanisms are inherently lossless, therefore the energy pumped into the device is returned except for a small portion expended producing mechanical work.
[0007] Various power circuits are known within the art to drive transductive mechanisms. Linear driver circuits are the most common approach. Linear drivers are very inefficient in that return energy from the transductive mechanism is dissipated thermally and thereby no longer available to drive the mechanism. Some improved performance is obtained with class D implementations of the electronics, however, the issue of how to store the transient return energy remains unresolved.
[0008] A more attractive solution to reverse energy flow is a regenerative driver circuit as disclosed in U.S. Pat. No. 6,001,345 issued to Murray et al. on Jan. 4, 2000. However, the invention by Murray suffers two fundamental problems. First, the invention requires a negative impedance inverter that is both quite complex to achieve and never adequately demonstrated in practice. Secondly, the invention requires a large output bypass capacitor. The capacitor value is chosen according to
R Load C Filter >>1 /F
[0009] where F is the ripple frequency. The ripple current is in this case impressed by the transients in and out during switching. This leads to a minimal requirement of the output bypass capacitor, where
C filter >>C load
[0010] as to achieve a ω 3db bypass. Consequently, the power bypass capacitor quickly becomes the dominating factor in terms of mass, volume, and performance at larger loads. The result is diminished advantages in terms of efficient power handling and compact implementation of the switching section in the drive topology.
[0011] The deficiencies of Murray et al. are best represented by example. Two symmetric load devices each consisting of two transductive elements are described in FIGS. 8 and 10. Two symmetric load devices each consisting of four transductive elements are described in FIGS. 11 and 12. For discussion purposes, piezo-mechanical motion is induced by piezoelectric transducers with 5.5 μF capacitance operating at 200 volts peak amplitude. The total resultant piezo-capacitance is 22 μF (4 times 5.5) for dually-opposed implementations and 44 μF (8 times 5.5) for quadrature-opposed implementations. Circulating currents from the large piezo-capacitive load has a deleterious effect on a high-voltage power supply because of high ripple causing ‘gain’ ripple induced at the switching amplifier output. The result is decreased stability at higher loads. A bypass capacitor one-hundred times the piezo-capacitance, 2,200 μF and 4,400 μF respectively for the examples above, is required to lower the return ripple of the recirculating current. Such bypass capacitors must operate satisfactorily within the bandwidth of the system, at a minimum several hundred hertz. Such operating conditions provide serious design challenges for both regenerative and conventional driver circuits.
[0012] Conventional power circuits are designed to drive only one side of a transductive system. When applied to a symmetrically coupled transductive system, the lossless nature of the transducers requires nearly all of the input energy returned and either transferred out the system as thermal energy or recovered and redirected. If recovered, the energy is typically recycled with additional input side energy to drive the other symmetric load at the output side of the circuitry. The recovery-recycle methodology as applied to symmetrically coupled systems by conventional circuits produces large peaks in the power supply ripple current. Consequently, such systems are inherently unstable.
[0013] What is required is a power control circuit capable of rapidly redirecting energy between loads in a symmetrically coupled arrangement and specifically a system wherein said loads are transductive elements. The circuit should substantially reduce peak power loading without increasing total power demand. The circuit should eliminate the large bypass capacitor required in the related arts, thereby facilitating a smaller, lighter package. The circuit should eliminate the power supply related stability problems inherent to regenerative and conventional electroncs.
SUMMARY OF THE INVENTION
[0014] A first object of the present invention is to provide a small, lightweight electronic driver circuit eliminating the need for large d.c. power bypass capacitors to drive transducer actuated symmetric reactive load systems.
[0015] A second object of the present invention is to provide more volumetrically efficient d.c. power section by effectively removing peak power requirements, leaving only low-level average power to be serviced.
[0016] A third object of the present invention is to provide regenerative efficiency without the need for a large d.c. power bypass capacitor to drive transducer-actuated systems.
[0017] A fourth object of the present invention is to provide increased stability when electrically powering transducer-actuated symmetric reactive load systems at higher charge levels.
[0018] To these ends, the present invention provides a regenerative class D power circuit attached to a symmetrically terminated reactive load system. The power circuit incorporates a new balanced capacitive loading method using the pure reactive portion of the load itself as an energy storage element in the energy balance system. In the present invention either a half-bridge FET or dual half-bridge FET switching topology controls charge-discharge between the two halves of a symmetric reactive load system. The invention can be implemented in the preferred embodiment consisting of a single half bridge or second embodiment consisting of dual half bridges driven 180 degrees out of phase. The topology of the present invention causes energy to be cycled from one side of the symmetric output load to the other side of the symmetric output load. Half-bridge averaging in the invention is externally commanded via a control module. When half-bridge averaging is commanded, an imbalance is caused producing current to flow in one desired direction only. The invention causes the charge to equilibrate between the two symmetric output loads in reference to the new average control module charge. The load on the driver at any given instant is the total output load, while load on the d.c. power supply is only the real power to the load used plus any switching losses. A control module, one example being a PWM, is employed as to institute power flow between symmetric loads as seen on the output side of the circuit. The present invention optimizes the coupling of energy in the L/C circuit comprising the symmetric loads as seen at the output of the circuitry.
[0019] The present invention minimizes power supply conditioning bypass capacitor requirements. Conventional half-bridge power supply circuits require a large bypass capacitor to filter all of the ripple current related to driving the reactive load. FIG. 1 a shows a conventional half-bridge arrangement wherein the ripple is related to
(X Load +Z load )×I Load
[0020] In the present invention, the circuit is required only to filter the ripple current related to the real power dissipated in driving the compound symmetric, reactive or more specifically capacitive, load. In the present invention, the load is a priori symmetrically divided and this fact is used to terminate the circuit uniquely as shown in FIG. 1 b . Thus, the current ripple is only related to
X Load ×I Load
[0021] The present invention offers several key advantages over class C, class D and class D regenerative circuitry. The present invention is lighter and smaller with increased efficiency over the related arts. The present invention significantly reduces the high-voltage power supply bypass capacitor representing the largest component in class D and regenerative class D circuitry. The present invention enables larger effective output filter values in a smaller package thereby increasing robustness. Thus, the present invention enables the compact, lightweight implementation for driving high-voltage symmetric output load systems. The present invention effectively enables higher switching voltage into symmetric output reactive load systems thereby retaining the high efficiency of regenerative drivers.
[0022] The present invention is applicable to a wide range of transductive systems including bimorph mechanisms, inchworm devices examples of which are described in U.S. Pat. Nos. 3,902,084, 3,902,085, 4,874,979, and 5,751,090, quadrature MEMS (micro-electromechanical systems) gearing, piezoelectric powered scroll compressors an example described in U.S. Pat. No. 4,950,135, and piezoelectric activated optical communication devices. The advantage of the present invention is that it substantially reduces the instantaneous loads on the high-voltage power supply. This in turn, significantly reduces the power supply mass and volume. In contrast to power switching electronics in the related arts, the present invention is easily miniaturized due to the elimination of large power filter components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:
[0024] [0024]FIG. 1 compares a conventional half-bridge switching mechanism with the present invention.
[0025] [0025]FIG. 2 describes charge transfer between two loads in series.
[0026] [0026]FIG. 3 shows a circuit diagram for a half-bridge embodiment of the present invention.
[0027] [0027]FIG. 4 graphically describes the voltage waveforms for a typical symmetric load system.
[0028] [0028]FIG. 5 graphically describes the energy flow waveforms for a typical symmetric load system.
[0029] [0029]FIG. 6 graphically describes the s witch states for a typical symmetric load system.
[0030] [0030]FIG. 7 is a circuit diagram for a dual half-bridge embodiment of the present invention.
[0031] [0031]FIG. 8 describes a bimorph embodiment of the present invention.
[0032] [0032]FIG. 9 shows a preferred embodiment of the bimorph embodiment.
[0033] [0033]FIG. 10 shows an example inch-worm implementation of the present invention.
[0034] [0034]FIG. 11 shows a generic quadrature implementation of the present invention.
[0035] [0035]FIG. 12 shows an example piezo-electric activated optical communications device incorporating the present invention.
REFERENCE NUMERALS
[0036] SW 1 First switch
[0037] SW 2 Second switch
[0038] L 1 Filter inductor
[0039] C 1 Bypass capacitor
[0040] [0040] 1 Switchmode power control circuit
[0041] [0041] 2 First load
[0042] [0042] 3 Second load
[0043] [0043] 4 Center tap
[0044] [0044] 5 Node B
[0045] [0045] 6 Node C
[0046] [0046] 7 Node D
[0047] [0047] 8 Node E
[0048] [0048] 9 Node F
[0049] [0049] 10 Switch controller circuit
[0050] [0050] 11 Power supply
[0051] [0051] 12 Node H
[0052] [0052] 13 Node I
[0053] [0053] 14 Regenerative drive
[0054] [0054] 16 Ground
[0055] [0055] 17 First single load
[0056] [0056] 18 Second single load
[0057] [0057] 19 Driver circuit
[0058] [0058] 20 Median axis
[0059] [0059] 22 First outer layer
[0060] [0060] 23 Second outer layer
[0061] [0061] 24 First transductive element
[0062] [0062] 25 Second transductive element
[0063] [0063] 26 Middle layer
[0064] [0064] 27 Adhesive
[0065] [0065] 28 Bimorph actuator
[0066] [0066] 30 Planar configuration
[0067] [0067] 31 Upper layer
[0068] [0068] 32 Lower layer
[0069] [0069] 40 Phase differential controller
[0070] [0070] 41 First member
[0071] [0071] 42 Second member
[0072] [0072] 43 First actuator
[0073] [0073] 44 Second actuator
[0074] [0074] 45 Third actuator
[0075] [0075] 46 Fourth actuator
[0076] [0076] 48 Symmetric reactive load system
[0077] [0077] 50 Flex tensioner
[0078] [0078] 51 First tensioner
[0079] [0079] 52 Second tensioner
[0080] [0080] 53 Third tensioner
[0081] [0081] 54 Fourth tensioner
[0082] [0082] 55 First transverse element
[0083] [0083] 56 Center transverse element
[0084] [0084] 57 Second transverse element
[0085] [0085] 58 Mechanical connector
[0086] [0086] 59 Mechanical ground
DESCRIPTION OF THE INVENTION
[0087] [0087]FIG. 2 generally describes the present invention at a functional level. The invention consists of a first load 2 , a second load 3 , and a driver circuit 19 . Both first load 2 and second load 3 have identical mechanical and electrical impedance. The driver circuit 19 provides d.c. voltage to both first load 2 and second load 3 arranged in series such that at equilibrium one-half of the total voltage (V) from the power supply 11 within the driver circuit 19 resides within the first load 2 (V/2) and the second load 3 (V/2). This condition is referred to as the equilibrated charge state and is represented in FIG. 2 a.
[0088] The driver circuit 19 cycles and recycles power between the first load 2 and the second load 3 via the charge transfer process. In FIG. 2 b , the driver circuit 19 directs power from the first load 2 to the second load 3 . While the total voltage (V) across first load 2 and second 3 equals the power supply 11 voltage, more voltage resides within the second load 3 . In FIG. 2 c , the driver circuit 19 redirects power from the second load 3 to the first load 2 . Again while the total voltage (V) across first load 2 and second load 3 is equal to the power supply 11 voltage, more voltage now resides within the first load 2 . In both charge flow descriptions, the driver circuit 19 alters current flow within a half-bridge topology via opening (OFF condition) and closing (ON condition) of two switches. During charge transfer, the load from which charge is directed is functionally an energy storage element facilitating the transfer process.
[0089] The switchmode power control circuit 1 including a first load 2 and second load 3 connected to a driver circuit 19 . The driver circuit 19 consists of a filter inductor L 1 , a regenerative drive 14 , a bypass capacitor C 1 , and a power supply 11 . FIG. 3 describes the half-bridge embodiment of the switchmode power control circuit 1 . First load 2 and second load 3 are connected in series at the center tap 4 , node B 5 , and node D 7 . The negative terminal from the first load 2 is connected to the positive terminal from the second load 3 at the center tap 4 . The positive terminal from the first load 2 is connected to node B 5 thereby aligning the positive terminal with the positive output on the power supply 11 . The negative terminal from the second load 3 is connected to node D 7 thereby aligning the negative terminal with the negative output on the power supply 11 . A filter inductor L 1 is connected to the center tap 4 between first load 2 and second load 3 and node C 6 between first switch SW 1 and second switch SW 2 . Nodes B 5 , C 6 , and D 7 facilitate connection of first load 2 , second load 3 , and filter inductor L 1 to the regenerative drive 14 . The regenerative drive 14 consists of a first switch SW 1 , a second switch SW 2 , and a switch controller 10 . First switch SW 1 and second switch SW 2 are connected in series to node B 5 , node D 7 , and dually to node C 6 thereby parallel to both first load 2 and second load 3 . A switch controller circuit 10 is connected to both first switch SW 1 and second switch SW 2 . Parallel to both first switch SW 1 and second switch SW 2 and opposite of both first load 2 and second load 3 is a bypass capacitor C 1 connected at node E 8 and node F 9 . A power supply 11 is connected adjacent to the bypass capacitor C 1 . The power supply 11 is of finite impedance and applies d.c. voltage to the driver circuit 19 . The power supply 11 replenishes voltage lost during switching and that portion expended by first load 2 and second load 3 .
[0090] The regenerative circuit 14 is known within the art. A typical embodiment consists of a first switch SW 1 , second switch SW 2 , and switch controller circuit 10 . Both first switch SW 1 and second switch SW 2 rapidly and alternately switch between OFF and ON, thereby adjusting current flow within the switchmode power control circuit 1 and energy flow between the first load 2 and the second load 3 . Example switches SW 1 , SW 2 include bipolar transistors, MOSFET's and IBGT's, all known within the art. The filter inductor L 1 stores energy when either first switch SW 1 or second switch SW 2 is ON thereby providing a temporary charge flow bias at the onset of the next switching condition. The switch controller circuit 10 consists of a high-frequency PWM modulator and driver circuitry known within the art. The switch controller circuit 10 controls timing and duration of OFF and ON conditions at first switch SW 1 and second switch SW 2 . In preferred embodiments, OFF and ON switching at both first switch SW 1 and second switch SW 2 occurs at frequencies in the hundreds of kilohertz. The PWM is modulated with the desired waveform, examples including but not limited to sine, square, and sawtooth waves. The bypass capacitor C 1 compensates for alternating current conditions at the power supply 11 thereby eliminating current ripple. The switchmode power control circuit 1 is terminated to a ground 16 by methods known within the art.
[0091] First load 2 and second load 3 may consist of one or more capacitive elements. In the most preferred embodiment, both first load 2 and second load 3 are mechanically and electrically matched transductive element. While various embodiments are possible, the total mechanical and electrical impedance of the first load 2 closely approximate that of the second load 3 . A second embodiment for non-symmetric loading conditions consists of an approximately chosen passive capacitor whose value added to none or partial existing second load 3 now matches the first load 2 in non-resonant applications.
[0092] [0092]FIG. 4 describes typical voltage waveforms at both first load 2 and second load 3 . FIG. 5 describes typical energy flow waveforms for first load 2 and second load 3 . Both Figures assume a sinusoidal command function from the switch controller circuit 10 into the first switch SW 1 and the second switch SW 2 . However, any fixed or variable function is applicable to the present invention. FIG. 6 artistically describes OFF and ON conditions at first switch SW 1 and second switch SW 2 for waveforms profiles in FIGS. 4 and 5 to aid functional visualization.
[0093] The equilibrated charge state is identified in FIG. 4 as a horizontal line with a magnitude V/2 representing one-half the total voltage (V) across the power supply 11 . This condition is maintained by the rapid OFF and ON switching of first switch SW 1 and second switch SW 2 at a constant frequency of equal duty cycle duration. Neither charge nor discharge occur at the equilibrated charge state. Voltage at center tap 4 is one-half of the power supply 11 voltage (V) and at node C 6 is either the power supply 11 voltage (V) or zero.
[0094] Charge transfer from the second load 3 to the first load 2 is achieved by increasing the duration of the ON condition at the second switch SW 2 thereby causing a corresponding increase in the OFF condition at the first switch SW 1 . Switching bias increases the discharge of energy at the second load 3 facilitating redirection to the first load 2 . Alternatively, charge transfer from the first load 2 to the second load 3 is achieved by increasing the duration of the ON condition at the first switch SW 1 thereby causing a corresponding increase in the OFF condition at the second switch SW 2 . Here, biased switching effectively increases the discharge of energy at the first load 2 and redirects it into the second load 3 . The resultant voltage waveforms for both first load 2 and second load 3 are sinusoidal however phase shifted 180 degrees. The total sum voltage at any time is equal to the power supply 11 voltage (V). The energy flow waveforms for first load 2 and second load 3 are also sinusoidal and phase shifted 180 degrees. Additionally, current and energy flow waveforms for each of the first load 2 and second load 3 are phase shifted 90 degrees.
[0095] The charge transfer process at the circuit level is the following. When the first switch SW 1 is ON and the second switch SW 2 is OFF, current in the filter inductor L 1 , accumulated when the second switch SW 2 was ON charging node C 6 to V and center tap 4 to V/2, continues to flow in the positive direction for a short duration into the first switch SW 1 . Thereafter, the charge direction reverses into the filter inductor L 1 since voltage at node C 6 is now zero and the voltage at center tap 4 is V/2. This charge flow pattern effectively “pulls” current from center tap 4 through first load 2 and second load 3 and “pushes” current into the ground 16 . When the first switch SW 1 is OFF and the second switch SW 2 is ON, current in the filter inductor L 1 , accumulated when the first switch SW 1 was ON causing node C 6 to have no voltage and placing center tap 4 at V/2, continues to flow in the negative direction for a short duration into the second switch SW 2 . Thereafter, the charge direction reverses away from the filter inductor L 1 since voltage at node C 6 is now the power supply 11 voltage (V) and the voltage at center tap 4 is one-half the power supply 11 value. This charge flow pattern effectively “pulls” current from node C 6 and “pushes” current through the first load 2 and second load 3 . But because the loads are not referenced to the same point, the current causes a differential variation in the loads thereby effectively producing the “pushing” and “pulling” described above.
[0096] [0096]FIG. 7 illustrates a dual half-bridge embodiment of the present invention wherein a first single load 17 and a second single load 18 are respectively connected to a filter inductor L 1 , a regenerative drive 14 , and a bypass capacitor C 1 and thereafter connected to a common power supply 11 at node H 12 and node 113 . In this embodiment, charge-discharge at the first single load 17 and second single load 18 are independent of one another. When the first switch SW 1 a is ON and the second switch SW 2 a is OFF, charge flows from positive to negative across the first single load 17 . When the first switch SW 1 a is OFF and the second switch SW 2 a is ON, charge flows from negative to positive across the first single load 17 . When the first switch SW 1 b is ON and the second switch SW 2 b is OFF, charge flows from positive to negative across the second single load 18 . When the first switch SW 1 b is OFF and the second switch SW 2 b is ON, charge flows from negative to positive across the second single load 18 . Alternating functionality between first single load 17 and second single load 18 is achieved by phase shifting command functions from the switch controller circuits 10 a and 10 b . A 180 degree phase shift is implemented in the preferred embodiment. While the single half-bridge shown in FIG. 3 was applicable to capacitive elements, the dual half-bridge embodiment is applicable to either dually arranged inductive or dually arranged capacitive elements.
[0097] Examples 1 through 4 demonstrate implementations of the present invention to symmetric reactive load systems 48 .
EXAMPLE I
[0098] [0098]FIG. 8 describes the extension of the present invention to a new device within the class of referred to as bimorphs. The switchmode power control circuit 1 is a mechanical half-bridge in this system. A bimorph actuator 28 consists of a plurality of planar members about a median axis 20 . The preferred embodiment consists of a middle layer 26 sandwiched between a first transductive element 24 and a second transductive element 25 . The middle layer 26 is a material sufficient to isolate the first transductive element 24 from the second transductive element 25 . Transductive elements 24 , 25 may consist of one or more capacitive elements, however the total capacitance of both transductive elements 24 , 25 are approximately equal. In the preferred embodiment, a first outer layer 22 and a second outer layer 23 further sandwich the transductive elements 24 , 25 . The outer layers 22 , 23 are any stiff yet flexible homogeneous or composite material with the preferred embodiment being a metal. In the most preferred embodiment, the transductive elements 24 , 25 are bonded to the middle layer 26 and outer layers 22 , 23 .
[0099] The bimorph actuator 28 forms a planar configuration 30 either when no charge is applied to the transductive elements 24 , 25 or when equal charges are applied within the switchmode power control circuit 1 to the transductive elements 24 , 25 , as shown in FIG. 8 a . The planar configuration 30 is altered via the driver circuit 19 by the charge transfer method. Charge transfer is achieved when the charge balance is altered between transductive elements 24 , 25 resulting in biased displacement of the bimorph actuator 28 , sometimes referred to as the unimorph effect. FIG. 8 b shows upward curvature in the bimorph actuator 28 about the median axis 20 when charge is removed from the first transductive element 24 and applied to the second transductive element 25 . FIG. 8 c shows downward displacement in the bimorph actuator 28 about the median axis 20 when charge is removed from the second transductive element 25 and applied to the first transductive element 24 . Charge flow directions are noted in FIGS. 8 b and 8 c . The amount of displacement is limited by the charge saturation characteristics of the transductive elements 24 , 25 and the stiffness of the bimorph actuator 28 .
[0100] [0100]FIG. 9 shows a preferred embodiment of the bimorph actuator 28 functioning as an actuator. The pre-stressed bimorph actuator 28 consists of a steel or titanium middle layer 26 , a piezoceramic first transductive element 24 , a piezoceramic second transductive element 25 , an aluminum first outer layer 22 , and an aluminum second outer layer 23 wherein layers 22 , 23 , 26 and elements 24 , 25 are bonded by an adhesive 27 . In other embodiments, an upper layer 31 and a lower layer 32 are applied to the bimorph actuator 28 consisting of a low-friction material preferably polytetrafluoroethylene. The most preferred embodiment consisting of the following: outer layers 22 , 23 being a 1.96 inch wide by a 1.96 inch long by a 0.001 inch thick aluminum, ASTM B20, plate; transductive elements 24 , 25 being a 2.04 inch wide by 2.04 inch long by 0.015 inch thick 3195HD ceramic manufactured by the CTS Corporation of Albuquerque, N. Mex.; middle layer 26 being a 3.0 inch wide by 2.24 inch long by 0.02 inch thick stainless steel plate, type 302, ASTM A117; and adhesive 27 being a high temperature polyimide commonly known as LaRC-SI.
[0101] The preferred embodiment is assembled with the following process. The outer layers 22 , 23 are perforated and cleaned. The piezoceramics are cleaned and sprayed with LaRC-SI solution (e.g., 8% LaRC-SI powder and 92% N-methyl-pyrolidinone) and then dried in an oven. The middle layer 26 is scuffed, primed, piezoceramics applied to the middle layer 26 , and outer layers 22 , 23 applied to the piezoceramics. A pre-heat step may be used to soften the adhesive 27 and provide the adherence required to keep elements 24 , 25 and layers 22 , 23 , 26 together during assembly. An alcohol solution also serves the same purpose. To insure a uniform bond, a vacuum bagging process is used to plate and fixture as to apply equal pressure onto individual elements while in the autoclave. The bimorph actuator 28 is placed into the autoclave, platen pressed, and subject to a pressure and temperature. During the autoclave cycle, the bimorph actuator 28 is heated, squeezed, cooked, then cooled to room temperature. During cool down, differences in the thermal coefficients of expansion between metals and ceramic creates a stress state within the material resulting in a flat planar configuration 30 .
[0102] The bimorph actuator 28 is polarized on either the outside of each ceramic or on the top of each ceramic. Three wires are attached to the structure. One wire is attached to the first outer layer 22 thereby providing a positive. A second wire is attached to the second outer layer 23 thereby providing a negative. And a third wire is attached to the middle layer 26 for grounding.
[0103] A multilaminar version of the bimorph actuator 28 is realized by the sequential layering of two or more bimorph actuators 28 separated by a frictionless material as described by the upper layer 31 and the lower layer 32 . Two electroding options are possible. The first option consists of similarly poling and driving the piezoceramics in parallel on one side of the median axis 20 , thereby functioning as the first load 2 , and similarly poling and driving the piezocermics in parallel on the opposite side of the median axis 20 , thereby functioning as the second load 3 . The second option alternates poling and electroding thereby treating odd numbered piezoceramics as the first load 2 and even numbered piezoceramics as the second load 3 .
EXAMPLE II
[0104] [0104]FIG. 10 describes the application of the present invention to a symmetric reactive load system 48 consisting of two identical but opposed induced strain devices. Such systems are referred to as inchworm or bi-static motion devices, and generally identified as two-state machines. The driver circuit 19 functions as a symmetric mechanical half-bridge between a first transductive element 24 and a second transductive element 25 . The transductive elements 24 , 25 are typically induced strain transducers having equal mechanical and electrical impedance.
[0105] [0105]FIG. 10 a shows a typical two-state machine either when no charge is applied to the transductive elements 24 , 25 or when equal charge is applied to the transductive elements 24 , 25 via the driver circuit 19 . This condition is referred to as the equilibrated charge state. In this example, the length of the transductive elements 24 , 25 are altered by redirecting charge, thereby altering the equilibrated charge state, between the transductive elements 24 , 25 via the driver circuit 19 . In FIG. 10 b , charge is removed from the first transductive element 24 and directed into the second transductive element 25 . As charge flows from the first transductive element 24 there is a decrease in the induced mechanical strain within the transductive element 24 thereby causing mechanically contractive displacement. As charge flows into the second transductive element 25 there is an increase in the induced mechanical strain within the transductive element 25 thereby causing a mechanically extensive displacement. The degree of displacement is limited by the charge saturation limit of the second transductive element 25 . To reverse the mechanical effect, the driver circuit 19 removes charge from the second transductive element 25 and returns it to the first transductive element 24 , as shown in FIG. 10 c . As the charge on the second transductive element 25 decreases, the mechanical strain causing its extension is reduced causing a corresponding decrease in its length. As the charge on the first transductive element 24 increases, mechanical strain within the transductive element 24 increases causing its extension. The degree of displacement is limited by the charge saturation limit of the first transductive element 24 . The driver circuit 19 and its application herein operates quasi-statically, over varying frequency or at resonance and applicable to piezo-motors, precision positioners, z-y stepping systems, and piezo-based differential control isolation systems.
EXAMPLE III
[0106] [0106]FIG. 11 describes the application of the present invention to a symmetric reactive load system 48 consisting of a quadrature arrangement of equal reactance transductive mechanisms sharing identical mechanical and electrical impedance. A first actuator 43 , a second actuator 44 , a third actuator 45 , and a fourth actuator 46 are arranged in a quadrature to produce motion between a first member 41 and a second member 42 via the linear extension and contraction of the actuators 43 , 44 , 45 , 46 . Orbital motion between first member 41 and second member 42 is applicable to scroll compressors. Rotational motion between the first member 41 and second member 42 is applicable to MEMS gearing. The actuators 43 , 44 , 45 , 46 are typically induced strain transducers. One embodiment of the symmetric reactive load system 48 consists of two orthogonal actuators, for example the first actuator 43 and the second actuator 44 . Another embodiment consists of two pairs of orthogonal arranged actuators 43 , 44 , 45 , 46 , as shown in FIG. 11. In the latter embodiment, the first actuator 43 and third actuator 45 are driven in parallel, as well as the second actuator 44 and fourth actuator 46 .
[0107] The extension and contraction of the actuators 43 , 44 , 45 , 46 are achieved via the driver circuit 19 using the charge transfer method described in Example II. The equilibrated charge state exists either when the charge to the first actuator 43 and the third actuator 45 are equal and the charge to the second actuator 44 and the fourth actuator 46 are equal or when no charge resides in all four actuators 43 , 44 , 45 , 46 . A phase differential controller 40 insures a ninety-degree phase shift at the third actuator 45 and the fourth actuator 46 .
[0108] The driver circuit 19 avoids driving actuator pairs 43 and 45 , 44 and 46 at piezo-resonance via a dual half-bridge topology, thereby developing only mechanical resonance. This mechanical resonance approach uses a single half-bridge output stage in a self-oscillatory system avoiding direct coupling between the energy in the resonant circuit and pressure in the system. The resultant system either operates in an electrically resonant mode or a electrical-mechanical resonant mode. The direct drive mode possesses a simpler method of feedback control than the non-resonant mode. It should be noted that in the direct drive mode the actuators 43 , 44 , 45 , 46 must operate in a bipolar voltage mode.
EXAMPLE IV
[0109] [0109]FIG. 12 describes the application of the present invention to a two-state bidirectional device referred to as a flex tensioner 50 . A typical flex tensioner 50 consists of four identical but dually opposed induced strain mechanisms referred to as a first tensioner 51 , a second tensioner 52 , a third tensioner 53 , and a fourth tensioner 54 . Each tensioner 51 , 52 , 53 , 54 may consist of one or more transductive elements 24 , 25 . Extension and contraction of the tensioners 51 , 52 , 53 , 54 are achieved and coordinated via the driver circuit 19 using the charge transfer method described in Example II. An equilibrated charge state exists either when equal charge is applied to each of the tensioners 51 , 52 , 53 , 54 or when no charge is present in all tensioners 51 , 52 , 53 , 54 .
[0110] In the method of operation of the present invention, the driver circuit 19 transfers charge from first tensioner 51 and fourth tensioner 54 to the second tensioner 52 and third tensioner 53 . During charge transfer, an external charge is applied via the driver circuit 19 to maintain the sum total charge in the tensioners 51 , 52 , 53 , 54 . Charge depletion in the first tensioner 51 and the fourth tensioner 54 causes the first transverse element 55 and second traverse element 57 to expand in a mechanically amplified fashion due to outward displacement. Simultaneously, charge addition in the second tensioner 52 and the third tension 53 causes the center transverse element 56 to compress along its length in a mechanically amplified fashion due to inward displacement. Mechanical connectors 58 between first tensioner 51 and second tensioner 52 and between third tensioner 53 and fourth tensioner 54 insure compression of the center transverse element 56 . Mechanical grounds 59 are positioned along the flex tensioner 50 .
[0111] Extension of the center transverse element 56 is achieved by diverting charge flow from second tensioner 52 and third tensioner 53 to first tensioner 51 and fourth tensioner 54 via the driver circuit 19 . First tensioner 51 and fourth tensioner 54 produce inward displacement adjacent to the first transverse element 55 and the second transverse element 57 . Second tensioner 52 and third tensioner 53 produce outward displacement adjacent to the center transverse element 56 . The magnitude of compression and extension within the center transverse element 56 is voltage dependent. Voltage and current are monitored at each tensioner 51 , 52 , 53 , 54 . Values are analyzed by the driver circuit 19 so that voltage levels are maintained and so that charge compensation is provided to offset mechanical and switching losses.
[0112] The description above indicates that a great degree of flexibility is offered in terms of the present invention. Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein. | The invention described herein is a novel power circuit capable of electrically driving devices whose mechanical action is accomplished by induced strain transducers. The power circuit neither recycles nor dissipates the energy returned from the near lossless transducer, instead redirects power either to another transducer of the same type or to the transducer itself. The invention is based on a balanced capacitive loading method wherein the load itself acts as the energy storage element in the energy balance system. In the preferred mode, the circuit directs power to a symmetric couple where both loads in the couple consist of one or more transductive elements. The invention eliminates the need for a large power-supply bypass capacitor in driving reactive loads thereby reducing the peak power handled by the d.c. power section. | 8 |
BACKGROUND OF THE INVENTION
This invention was made under U.S. Government Contract No. DAMD-17-83-C-3128 and the United States Government has a non-exclusive, nontransferable, irrevocable, paid-up license to practice or have practiced for or on behalf of the U.S., this invention throughout the world.
The present invention relates to polymeric decontamination compositions intended to counter the effects of toxic chemical agents such as the highly toxic chemical warfare agents known as G-agents which are broadly organic esters of substituted phosphoric acid as well as other toxic phosphorylating agents as are present in certain insecticides.
Such phosphorylating agents are generally colorless and odorless gases and are readily absorbed through the skin and depending on the particular phosphorylating agents can cause reactions in humans and other animals varying from minor neurological disorders such as disorientation to death.
Efforts to combat against such toxic agents includes protective garments, the use of atropine and pralidoxime to neutralize the effects of such agents and reactivate the inhibited enzymes, and chemical neutralizers. At the present time, one of the most effective decontamination compositions is the chemical neutralizer DS2 (diethylenetriamine in a caustic solution). Such solution often also contains methyl cellosolve as a thickener in order to keep the neutralizer in place on the skin of the animal or other surface so that it can act over a long period of time to decontaminate the toxic phosphorylating agent.
However, such decontamination solutions as DS2 are very corrosive to the skin and while adequate for the contamination of surfaces such as on vehicles, they are not suitable for use on the skin of animals and particularly humans.
Efforts to maintain the effectiveness of compounds such as DS2 while eliminating the skin irritation and corrosiveness have not been successful.
SUMMARY OF THE INVENTION
The present invention provides an effective decontamination composition for decontaminating toxic phosphorylating agents which are not toxic to the skin or irritating thereto.
Briefly, the present invention comprises a polymeric decontamination composition comprising the polymeric reaction product resulting from the reaction of a polyvinylbenzyl halide and a monomeric amine, and swollen with an alkali metal hydroxide composition.
The invention also comprises the method of making such composition as more fully set forth hereinafter.
DETAILED DESCRIPTION
The present composition is effective against the toxic phosphorylating agents utilized in chemical warfare agents and in certain insecticides. In terms of the chemical warfare agents involved, they are commonly known as G-agents with examples being TABUN (GA), SARIN (GB), and SOMAN (GD). These particular agents are highly toxic by injection, inhalation, as well as by skin absorption and are fatal on short exposure They are in effect nerve gases that function by inhibiting cholinesterase enzymes and a medical defense against individuals exposed by inhalation to such compounds involves the use of atropine and pralidoxime to neutralize the effects of the compounds and to reactivate the inhibited enzymes.
In the description that follows and in the specific examples the activity of the compositions of the present invention has been tested against diethylchlorophosphate (DECP) since this compound while also a cholinesterase inhibitor and toxic through ingestion, inhalation and skin absorption is not as dangerous and is in liquid form and can be more readily handled for testing purposes It is used and has been used herein as the test vehicle since it simulates the reactivity of the other cholinesterase inhibitors such as the G-agents.
The polymeric decontamination composition of the present invention has as its essential components the polymeric reaction product resulting from the reaction of a polyvinylbenzyl halide and a monomeric amine, and then swollen with an alkali metal hydroxide composition.
As to the polyvinylbenzyl halide, it is preferably a chloride and the monomeric amine is preferably diethylene triamine although other monomeric amines such as ethylene diamine, triethylene tetramine, tetraethylene pentamine, dimethylamine, diethylamine, methylamine, ethylamine, ethanolamine, diethanolamine, and the like can be used.
The polyvinylbenzyl halide is first dissolved in any of the usual solvents therefor such as methylene chloride and the reaction is carried out the ambient temperature and pressure, although more elevated temperatures and pressures can be utilized if desired. While stoichiometric amounts of the two reactants can be utilized, it is preferred to use an excess of the amine. The excess amine is used so that it will react with the HCl formed and result in an amine hydrochloride which is readily removable from the reaction product medium by water. The reaction carried out with agitation until essentially complete. Completion is determined by noting the formation of a thick slurry.
The result is a polymeric reaction product which results from the following reaction: ##STR1##
In these formulas, X is a halide and n is an integer of at least 10.
This resulting dried reaction product is then ground to form a fine powder and is then treated with alkali metal hydroxide composition. The hydroxide composition swells the reaction product to form a swollen mass.
The hydroxide composition consists of the alkali metal hydroxide and a swelling agent; the I0 hydroxide is preferably sodium hydroxide and swelling agent being any compound or mixture of compounds that can dissolve the hydroxide and be absorbed by the polymer. While any hydroxy polar ether can be used for this purpose methyl cellosolve is preferred although other cellulose ethers, polyethylene glycol and the like meeting the above criteria can be used. The amount of the hydroxide composition added is not important; so long as care is taken not to add an amount to swell the reaction product; ordinarily about 1 to 5 parts by weight for each 100 parts by weight of polymer. The hydroxide composition can contain from about 8 to 15 parts by weight of a hydroxide dissolved in 100 parts by weight of methylcellosolve; preferably 10 parts by weight of hydroxide.
The invention will be further described in connection with the following examples which are set forth for purposes of illustration only.
EXAMPLE 1
Polyvinylbenzyl diethylenetriame was prepared by first forming a solution of 40 g of polyvinylbenzyl chloride in 500 ml of methylene chloride in a reactor kept at ambient temperature and pressure. There was added to the solution 54.1 g of diethylenetriamine in 150 ml of methylene chloride and the resulting reaction mixture stirred at room temperature and pressure for 48 hours at which time the reaction was complete.
Approximately 1,000 ml of methanol was then added to the reaction mixture and the methylene chloride, and some methanol, removed by vacuum evaporation. The approximately 700 to 80 ml of the reaction medium remaining was diluted to 4,000 ml with demineralized water and the solid formed was removed by filtration using a Buchner funnel. The liquid contained the amine hydrochloride salt. The solid was washed once with 500 ml of water and then air dried followed by drying in an oven.
The theoretical yield was 57.5 g and measurement lenetriamine) showed a yield of 54.1 g or 94% of theoretical.
The resulting product was ground to a fine powder and 15 g thereof were added to a solution of 22.6 g of NaOH in 203.7 g of methyl cellosolve. The mixture was agitated for seven days and then the solid filtered off and washed once with about 200 ml of methyl cellosolve.
The result was 45.4 g of swelled polyvinylbenzyl diethylenetriamine.
EXAMPLE 2
The procedure of Example 1 was followed except that ethylene diamine was used instead of diethylene triamine.
More particularly, 13.02 g of polyvinylbenzyl chloride and 100 ml of methylene chloride were placed in a reaction vessel and then 12.2 g of ethylene diamine in 100 ml of methylene chloride added. The reaction was carried out at ambient temperature and pressure for 72 hours with stirring. At the end of that time a thick mass of precipitated reaction product had formed.
To this reaction product there was added 800 ml of ethanol and 1,000 ml of water and the entire mixture was then filtered. The filtered solids were then mixed with 3,000 ml of water and stirred for 30 minutes, filtered, and then dried in an oven at 75° F.
The dried product weighed 15.06 g and was polyvinylbenzyl ethylenediamine.
EXAMPLE 3
18.8 g of polyvinylbenzyl diethylene triamine were added to a solution of 28.4 g of NaOH in 255 g of methyl cellosolve. The mixture was agitated for five days, the solid filtered off, was once washed by slurrying in 200 ml of methyl cellosolve, refiltered, and then blotted dry by pressing between filter paper for about one minute. The swelled product was then tested using the Southwest Research Institute 4-minute test procedure to determine their effectiveness when decomposing diethylchlorophosphate.
The four minute test comprises taking a 200 mg sample of the product to be tested, placing it in a 1-dram vial along with two 6-mm Pyrex glass beads and capping the vial with a polyseal cap. The vial and contents are placed in a 37° C oil bath and allowed to equilibrate to temperature for about 15 to 30 minutes.
Once the temperature has equilibrated, a measured amount of the DECP is added to the sample. The sample with DECP are mixed for 1 minute using vortex mixer to ensure complete contact of DECP and sample. The vial with contents is replaced in the 37° C oil bath for an additional 3 minutes. This exposure time can be extended. 8, 16, 60 and 120 minutes are utilized to determine the effects of time on the decomposition of DECP.
Two milliliters of diethyl ether (Et.sub. 20) are added to the vial after the sample and DECP have been in contact for the allotted time, and the vial capped.. The heterogeneous mixture is vortexed for 5 seconds and centrifuged for 1 minute. The ether layer is withdrawn to a clean labeled vial via a Pasteur pipette and assayed for DECP content by gas chromatography (GC). The peak height of the DECP from the test sample is compared with the GC peak height of a standard sample. The standard sample is prepared from the same measured amount of DECP which was placed in a vial and is placed in a 37° C oil bath. Two milliliters of diethylether are added and the standard assayed by GC.
The percentage decomposition of the DECP is determined by the ratio of peak heights of the test sample relative to the standard sample. One standard sample and four replicate test samples are prepared and assayed for each evaluation. The standard sample is assayed twice, once before the test samples and once after the test samples to ensure reproducibility of the standard.
The results of the tests over time are shown in Table I set forth below:
TABLE I______________________________________Test Amt. of % DecompositionRun DCEP Time Temp. of DECP Deviation______________________________________A 50 (μL) 8 37° C. 81.7 3.4B 50 (μL) 16 37° C. 91.6 2.2C 50 (μL) 60 37° C. 98.4 0.0D 50 (μL) 120 37° C. 99.2 0.0______________________________________
While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | A polymeric decontamination composition comprising a polymeric reaction product resulting from the reaction of a polyvinylbenzyl halide and a monomeric amine admixed with an alkali metal hydroxide solution capable of swelling said polymeric reaction product and the method of making the composition. | 2 |
RELATED APPLICATION
This application relies for priority upon Korean Patent Application No. 2002-05052, filed on Jan. 29, 2002, the contents of which are herein incorporated by reference in their entirety.
1. Field of the Invention
The present invention relates to methods for fabricating semiconductor devices and, more particularly, to methods for fabricating MOS transistors with notched gate electrodes.
2. Background of the Invention
As semiconductor devices become increasingly integrated, the area occupied by MOS transistors on integrated circuits has been gradually reduced. As the channel length of a MOS transistor decreases, there may arise a short channel effect (SCE), which seriously deteriorates the characteristics of the transistor. The SCE is caused by the phenomena of drain-induced barrier lowering (DIBL), punchthrough, hot carriers, and the like.
As the space between a source and drain decreases, electrons emitted from the source are sharply accelerated due to a high electric field in the vicinity of the edge of the drain junction region, which generates hot carriers, in turn causing characteristics of semiconductor devices to be degraded. The foregoing phenomenon is typically referred as the hot carrier effect. For this reason, MOS transistors of lightly doped drain (LDD) structures have been extensively used to improve degradation caused by the hot carriers.
FIG. 1 is a cross-sectional view of a MOS transistor of a conventional LDD structure.
Referring to FIG. 1, a device isolation layer 105 is formed in a semiconductor substrate 100 to define an active region. A gate stack, which includes a gate insulation layer 110 , a gate electrode 115 , and a gate spacer 125 , is formed on the active region. A lightly doped impurity region 120 and a heavily doped impurity region 130 are formed in the semiconductor substrate of both edges of the gate insulation layer 110 . The lightly doped and heavily doped impurity regions 120 and 130 correspond to source and drain regions.
In the LDD structure, the lightly doped impurity region 120 self-aligned to the gate electrode 115 is disposed between a channel region and the heavily doped impurity region 130 . The lightly doped impurity region 120 allows an electric field between the drain and channel regions to be reduced such that, even if a high voltage is applied to the drain region, carriers emitted from the source region are not sharply accelerated. As a result, adverse effects due to the hot carrier effect can be mitigated.
However, since parasitic capacitance, which is exhibited in the overlapped region of the gate electrode and the LDD region, reduces speed of devices, the LDD structure makes it difficult to realize a MOS transistor suitable for high-speed operation. To improve performance lowered by the LDD structure, MOS transistors with notched gate electrodes have been recently proposed.
FIG. 2 is a cross-sectional view of a MOS transistor with a notched gate electrode.
Referring to FIG. 2, a device isolation layer 205 is formed at a semiconductor substrate 200 to define an active region. A gate stack, which includes a gate insulation layer 210 , a notched gate electrode 215 , and a gate spacer 225 , is formed on the active region. A lightly doped impurity region 220 and a heavily doped impurity region 230 are formed in the semiconductor substrate of both edges of the gate insulation layer 210 . The lightly doped and heavily doped impurity regions 220 and 230 correspond to source and drain regions.
One of advantages of the notched gate electrode is that the channel length is substantially reduced by a notch region 235 formed under the gate electrode. This results in reduction of overlap capacitance between the gate and the source and between the gate and the drain. Therefore, transistors may be improved in their performance and speed.
In addition, since halo implantation is the technique used for ion implantation in the substrate including a notched gate electrode, this makes it possible to form a relatively deeper ion implantation region, as compared with a conventional gate electrode. Halo implantation is thus more effective in stopping punchthrough. According to halo implantation, the notch region 235 under the edge of the gate electrode does not inhibit the ion implantation.
Finally, the notched gate electrode is a T-shaped gate, the lower portion of which may have a shorter length than the upper portion. This permits silicide to be widely formed on the upper portion of the gate electrode, thus enabling lower resistance.
A conventional method for fabricating a notched gate electrode comprises patterning a gate electrode using photolithographic and etching processes through a specific etching method in order to form a notch region under an edge of the gate electrode. For example, after forming a gate conductive layer having a stacked structure of silicon germanium and polysilicon, an etching process is performed using a difference in etch rate to form the notched gate electrode. That is, the notched gate electrode is formed using the difference in etch rate between silicon germanium and polysilicon.
The problem of the conventional method is that it is difficult to realize the notch region at a desired size. In other words, a gate electrode cannot be readily formed to a desired length. In addition, in the dry etching process for forming the gate electrode, a plasma gas may transform the gate electrode and cause an electric charge to be generated in the gate electrode. This may lead to partial concentration of an electric field or a trap charge, thus lowering reliability of the gate insulation layer.
SUMMARY OF THE INVENTION
In addressing the aforementioned limitations, the present invention provides methods for fabricating MOS transistors with notched gate electrodes, which can form a gate pattern without the need for etching the gate conductive layer and, in this manner, provides enhanced control over the resulting width and a height of the notch region.
In accordance with broad aspects of the present invention, provided is a method for fabricating a MOS transistor with a notched gate electrode that comprises forming a multi-layered insulation layer including at least two insulation layers on a substrate. The multi-layered insulation layer is patterned to form an opening exposing a predetermined region of the substrate. The opening has a stair-shaped sidewall such that an upper portion of the opening is wider than a lower portion thereof. A gate insulation layer is then formed on the exposed substrate, and a gate electrode is formed on the insulation layer to fill the stair-shaped opening. The multi-layered insulation layer is then removed. As a result, a notched gate electrode, in which a notch region is formed under an edge of the gate electrode, is formed.
Forming the opening having the stair-shaped sidewall comprises forming upper and lower openings. After forming a multi-layered insulation layer including lower and upper molding layers, the upper molding layer is etched by using a mask pattern to form the upper opening. A self-aligned spacer is then formed on a side of the upper opening. By using the self-aligned spacer as an etch mask, the lower molding layer is etched to form the lower opening. This results in formation of the opening with a stair-shaped sidewall in which the upper opening is wider than the lower opening.
Another method for forming the opening with a stair-shaped sidewall employs photolithographic and etching processes twice. In other words, after forming a multi-layered insulation layer, which includes lower and upper molding layers, the photolithography and etching are performed into the upper molding layer by using a first mask pattern to form an upper opening. Thereafter, the lower molding layer is etched using a second mask pattern so as to form the opening with a stair-shaped sidewall in which the upper opening is wider than the lower opening.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features and advantages of the invention will be apparent from the more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is a cross-sectional view of a MOS transistor of a conventional LDD structure.
FIG. 2 is a cross-sectional view of a MOS transistor with a conventional notched gate electrode.
FIGS. 3A to 3 L are cross-sectional views for illustrating a method for fabricating a MOS transistor according to a first preferred embodiment of the present invention.
FIGS. 4A and 4B are cross-sectional views for illustrating a method for fabricating a MOS transistor according to a second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown.
Embodiment 1
FIGS. 3A to 3 L are cross-sectional views for illustrating a method for fabricating a MOS transistor according to a first preferred embodiment of the present invention.
Referring to FIG. 3A, a device isolation layer 305 is formed at a substrate 300 to define an active region. Lower and upper molding layers 317 and 337 are then formed on the substrate 300 . The lower molding layer 317 may include a sacrificial insulation layer 310 and a lower insulation layer 315 . The upper molding layer 337 may include an etch stop layer 320 , an upper insulation layer 325 , a polishing stop layer 330 , and a capping insulation layer 335 .
To form the sacrificial insulation layer 310 , thermal oxidation or CVD method is carried out into a silicon substrate such that a thin silicon oxide layer is formed on the substrate.
The lower insulation layer 315 may comprise, for example, a silicon oxide layer and is formed to have a thickness ranging from 50 to 1000 Å. The upper insulation layer 325 may comprise, for example, a silicon oxide layer and is formed to have a thickness ranging from 500 to 3000 Å. The lower and upper insulation layers 315 and 325 may be formed, for example, using plasma enhanced CVD (PECVD), high density plasma CVD (HDP-CVD), atmosphere pressure CVD (APCVD), or a spin coating technique.
The etch stop layer 320 may comprise, for example, a silicon nitride layer.
The polishing stop layer 330 is formed to stop polishing during a subsequent chemical mechanical polishing (CMP) procedure, and may comprise, for example, a silicon nitride layer.
The capping insulation layer 335 is formed to protect the polishing stop layer 330 during a subsequent etchback process and is composed of a material having an etch selectivity with respect to the polishing stop layer 330 , for example, a silicon oxide layer.
Referring to FIG. 3B, the capping insulation layer 335 , the polishing stop layer 330 , and the upper insulation layer 325 are selectively etched using a mask pattern until the etch stop layer 320 is exposed. Thus, an upper opening 340 is formed.
Referring to FIG. 3C, a spacer insulation layer is formed on an entire surface of the substrate including the upper opening 340 . An etchback process is carried out on the entire surface of the resultant substrate, thereby forming a self-aligned spacer 345 on a side of the upper opening 340 . The spacer insulation layer may comprise, for example, a silicon nitride layer, and is formed to have a thickness ranging from 5 to 500 Å. Since the spacer insulation layer and the etch stop layer 320 alike are silicon nitride layers, while forming the self-aligned spacer 345 , the etch stop layer 320 is likewise etched during this step to expose the lower insulation layer 315 . If the capping insulation layer 335 is not formed, the polishing stop layer 330 , which does not have an etch selectivity with respect to the spacer insulation layer, may be removed during the foregoing etchback process. The capping insulation layer 335 thus protects the polishing stop layer 330 .
Referring to FIG. 3D, by using the self-aligned spacer 345 as an etch mask, a dry etching process is performed into the lower insulation layer 315 using plasma to form a lower opening 350 exposing the sacrificial insulation layer 310 . When the lower insulation layer 315 is etched, the capping insulation layer 335 is partially removed. The width of the lower opening 350 may be adjusted according to the width of the self-aligned spacer 345 . Since the lower insulation layer 315 and the sacrificial insulation layer 310 , both of which are oxide layers, do not have etch selectivity with respect to each other, the etching time should be adjusted so as not to expose the substrate. In FIG. 3D, the sacrificial insulation layer 310 is illustrated as being over-etched.
Referring to FIG. 3E, the self-aligned spacer 345 is removed to form a stair-shaped opening 355 consisting of upper and lower openings 340 and 350 . The upper portion 340 of the stair-shaped opening 355 is wider than the lower portion 350 . In the present preferred embodiment, to form the stair-shaped opening, while the upper opening 340 is formed using photolithographic and etching processes, the lower opening 350 is formed by an etching process using the self-aligned spacer 345 as a mask. In the case of using the spacer 345 as a mask, the lower opening may be effectively formed at level of precision that is to be narrower than the critical dimension (CD) of the process.
Referring to FIG. 3F, a protecting spacer insulation layer may be thinly formed on an entire surface of the substrate. An etchback process may be then performed to form a protecting spacer 360 on the side portions of the stair-shaped opening 355 . The protecting spacer insulation layer may comprise, for example, a silicon nitride layer, and is formed to have a thickness ranging from 5 to 500 Å.
Referring to FIG. 3G, the sacrificial insulation layer 310 under the stair-shaped opening 355 is removed by a cleaning process to expose the substrate 300 . At this time, the protecting spacer 360 , which is formed on the side of the stair-shaped opening 355 , protects the side surfaces of the upper and lower insulation layers 315 and 325 , thereby preventing the stair-shaped opening 355 from becoming larger.
Referring to FIG. 3H, a gate insulation layer 365 is formed on the exposed substrate 300 . The gate insulation layer 365 may comprise at least one layer type selected from the group consisting of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, a zirconium oxide layer, a hafnium oxide layer, a tantalum pentaoxide layer, and an aluminum oxide layer. The gate insulation layer 365 has a thickness, for example, of 10 to 200 Å.
Referring to FIG. 3I, a gate conductive layer 370 is formed on the resultant structure having the gate insulation layer 365 at a depth that is enough to fill the stair-shaped opening 355 . The gate conductive layer may be composed of at least one selected from the group consisting of polysilicon, silicon germanium, cobalt, tungsten, titanium, and nickel. The gate conductive layer may have a thickness, for example of 500 to 3000 Å.
Referring to FIG. 3J, a CMP process is carried out into the gate conductive layer to form a gate electrode 370 . The CMP is performed until the polishing stop layer 330 is exposed. In the present preferred embodiment, the height of the lower and upper insulation layers 315 and 325 may be adjusted to adjust the resulting height of the polishing stop layer 330 . This enables the height of the gate electrode to be controlled.
Referring to FIG. 3K, the polishing stop layer 330 , the upper insulation layer 325 , the etch stop layer 320 , the lower insulation layer 315 , and the sacrificial layer 310 are removed to form a notched gate 370 . In this case, a portion of the insulation layer may be not etched and may therefore remain at the notch region 375 of the notched gate 370 . In FIG. 3K, the insulation layer is illustrated as being completely removed in the notch region. It is preferable that the width and height of the notch region 375 range from 5 to 50% of the overall width and a height of the notched gate.
Referring to FIG. 3L, impurities are doped into the substrate 300 by using the notched gate electrode 370 as an ion implantation mask to form a lightly doped impurity region 375 . A gate spacer insulation layer is formed on an entire surface of the substrate and an etchback process is performed into the resultant substrate to form a gate spacer 380 .
Next, impurities are doped into the substrate by using the gate electrode 370 and the gate spacer 380 as an ion implantation mask to form a heavily doped impurity region 385 . Consequently, fabrication of the MOS transistor is completed.
Embodiment 2
In a second preferred embodiment, unlike the first preferred embodiment, after forming an upper opening, a lower opening is formed by using a second mask pattern, rather than using the self-aligned spacer 345 shown above in FIG. 3 D.
FIGS. 4A and 4B are cross-sectional views for illustrating a method for fabricating a MOS transistor with a notched gate electrode according to a second preferred embodiment of the present invention.
Referring to FIG. 4A, a device isolation layer 305 is formed at a substrate 300 to define an active region. Lower and upper molding layers 317 and 337 are then formed on the resultant substrate where the device isolation layer 305 is formed. The lower molding layer 317 may include a sacrificial insulation layer 310 and a lower insulation layer 315 . The upper molding layer 337 may include an etch stop layer 320 , an upper insulation layer 325 , a polishing stop layer 330 , and a capping insulation layer 335 .
The upper molding layer 337 is patterned by using a first mask pattern 339 , which is formed using photolithography, as an etch mask, thereby forming an upper opening 340 exposing a surface of the lower molding layer 317 .
Referring to FIG. 4B, the first mask pattern 339 is removed, and a second mask pattern 349 is formed on the lower molding layer 317 , which is exposed in the upper opening 340 .
By using the second mask pattern 349 as an etch mask, the lower insulation layer 315 is etched to form a lower opening 350 . Since the lower insulation layer 315 and the sacrificial insulation layer 310 , both of which are oxide layers, do not have an etch selectivity with respect to each other, the etching time should be adjusted so as not to expose the substrate. In FIG. 4B, the sacrificial insulation layer 310 is illustrated as over-etched.
Thereafter, the second mask pattern is removed to obtain the resultant structure as illustrated above in FIG. 3 E. The subsequent steps are the same as those of Embodiment 1. Description of those steps will be omitted here.
The invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
According to the present invention as described above, a notched gate electrode may be readily formed using a damascene process for filling a stair-shaped opening. In addition, since a dry etching process is not applied to form the notch region, the gate electrode may avoid becoming transformed and electric charged due to plasma.
In addition, the width of the self-aligned spacer may be adjusted to form the gate electrode at a desired width.
Finally, the respective thicknesses of the lower and upper insulation layers may be adjusted to form the gate electrode at a desired height. | In methods for fabricating MOS transistors with notched gate electrodes, a notched gate electrode may be readily fabricated using a damascene process for filling a stair-shaped opening formed in a multi-layered insulation layer. In this manner, the width and a height of the notch region of the gate electrode may be readily adjusted and controlled. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a method and apparatus for creation of moire fabric. Traditional moire fabrics are defined as a wavy or watered effect on textile fabric, especially a corded fabric of silk, rayon, or one of the manufactured fibers. An excellent example of a corded fabric would be a faille. Failles are generally defined as having fine, bright, continuous filament warps and coarse spun filling and a plain weave. This creates a noticeable ribbed effect in the filling direction. Other fabrics can be utilized with typically lesser results, however, a visible ribbed effect should be present in the fabric's filling.
Moire fabric falls into one of two categories. The first is an uncontrolled moire when the filling ribs of one layer of fabric is intentionally skewed with respect to the second layer of fabric prior to applying pressure to both layers of fabric. This will result in a significant increase in the number of filling ribs that cross with the associated increase in vertical moire lines. This is very undesirable since the appearance of the moire fabric will never be consistent and will vary from batch to batch.
Traditionally, controlled moire fabric is formed by selectively distorting or skewing small portions of the filling ribs so that the filling ribs only cross in selective areas. The most common method is the Francais bar method in which ribbed woven fabric is dragged over a stationary bar which has a series of knobs which are spaced at desired intervals. This is done at very high tension. The knobs distort the filling into a bow wherever they touch the fabric. When two pieces of this fabric are subjected to pressure, a traditional controlled moire will result that is typically found in upholstery, drapery, apparel, and other end uses. Problems with this type of moire patterning include the fact that the pattern is repeatedly fixed and dragging under high tension can damage and/or destroy the fabric.
Another traditional method utilized in creating controlled moire fabric is the "scratch" method. This is accomplished by means of a resilient roll having the desired designs embossed thereon. These designs may include flowers, geometrics, and so forth. While the fabric is in contact with this embossed roll, it is "scratched" with a series of steel blades which distort the filling yarns of the fabric according to the pattern embossed on the roll. Upon applying pressure to two pieces of this treated fabric, a moire pattern is produced. Once again, there is the problem of the destruction or damage to yarns by the steel blades and a fixedly repeatable pattern. This "scratch" method produces very poor results with a large quantity of broken filaments. The blades actually only contact the warp yarns thus producing a large amount of broken filaments with only minimal movement of the filling yarn. It is the movement of the filling yarn that is the desired result. Furthermore, by examination of faille fabric, the filling is virtually covered by warp yarns and thus it is very difficult to move the filling by mechanical means. Also, this "scratch" method creates fuzz on the surface of the fabric that results in less shine and poor moire patterns.
Yet another traditional method of producing a controlled moire is by that found in U.S. Pat. No. 2,448,145, which discloses the selective application of water to fabric with a noticeable ribbed effect in the filling direction. The fabric is then placed under high tension and then dried. This will distort the filling yarns in the wet areas differently than the filling yarns in the dry areas. Again, upon applying pressure to two pieces of this treated fabric, a moire pattern is produced. A severe problem with this technology is that it would be very difficult to selectively wet yarns while leaving adjacent yarns dry for a very precise pattern. Furthermore, stretching under high tension can severely weaken or even destroy filling yarns. Furthermore, this method is deficient in that it only works on fibers that absorb large amounts of water such as cotton, silk and so forth. Each pattern requires a specific patterning roll or screen which only changes the pick count slightly in the areas treated with water. While this may produce some beating when the fabrics are sandwiched and calendered it does not produce true moire because the filling is not distorted with bow or skew.
The present invention solves these problems in a manner not disclosed in the known prior art.
SUMMARY OF THE INVENTION
An apparatus and method for creation of moire fabric. This can be achieved by placing a first piece of fabric against a support member and directing at least one stream of fluid at the surface of said first piece of fabric to provide lateral yarn displacement. Then delivering said stream at a peak dynamic pressure in excess of about 300 p.s.i.g. and less than 4,000 p.s.i.g. and selectively interrupting and re-establishing contact between said stream and said surface in accordance with pattern information in order to pattern said first piece of fabric. This is followed by combining said patterned first piece of fabric with an unpatterned second piece of fabric in overlapping relationship and applying pressure by means of calender rolls having smooth surfaces to said combination of said first piece of patterned fabric and said second piece of unpatterned fabric.
It has been found that by using high pressure liquid jets having a moment of force in the plane of the fabric that there will be movement of the filling yarns in the fabric. This movement of the filling yarn is produced without damage to the warp yarns.
It is an unexpected advantage of this invention that surface fuzz on the fabric is forced to the back of the fabric. When high pressure liquid is applied to the fabric and subsequently the fabric is sandwiched and calendered, then beautiful moire patterns are produced. The absence of fuzz in the patterned areas produces especially bright and clear moire patterns.
Yet another advantage of this invention is to have moire patterns of any length or, in other words, patterns that do not necessarily repeat.
Still another advantage of this invention is the means of patterning is relatively nondestructive and places a minimum of tension on the fabric.
Another advantage of this invention is extremely precise since it can selectively move individual yarns.
A further advantage of this invention is that patterning can be extremely complex with the only limits being those of the human imagination.
Another advantage of this invention is that patterning can be altered while the machine is processing and downloaded in real time with the only limits being those of the complexity of the available computer system utilized in the storage and retrieval of moire patterns.
These and other advantages will be in part apparent and in part pointed out below.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other objects of the invention will become more apparent from the following detailed description of the preferred embodiments of the invention when taken together with the accompanying drawings, in which:
FIG. 1 is a schematicized side view of an apparatus for generating selectively patterned fabric wherein an array of liquid jets is placed inside a stencil in the form of a cylinder, which in turn is brought into close proximity to the fabric surface;
FIG. 2 is a diagrammatic perspective view of the apparatus of FIG. 1;
FIG. 3 is an overview of yet another apparatus which may be used to generate selectively patterned ribbed fabric disclosed herein;
FIG. 4 is a perspective view of the high pressure manifold assembly depicted in FIG. 3;
FIG. 5 is a side view of the assembly of FIG. 4, showing the alignment means used to align the containment plate depicted in FIG. 4;
FIG. 6 is a cross-section view of the assembly of FIG. 4, without the alignment means, showing the path of the high velocity fluid through the manifold, and the path of the resulting fluid stream as it strikes a substrate placed against the support roll;
FIG. 7 depicts a portion of the view of FIG. 6, but wherein the fluid stream is prevented from striking the target substrate by the deflecting action of a stream of control fluid;
FIG. 8 is an enlarged, cross-section view of the encircled portion of FIG. 7;
FIG. 9 is a cross-section view taken along lines XVII--XVII of FIG. 8, depicting the deflection of selected working fluid jets by the flow of control fluid;
FIG. 10 is a diagrammatic side view of two supply rolls, two calendering rolls and two take-up rolls;
FIG. 11 is a photomicrograph (1.1×) of the face of the untreated faille fabric of Example 1;
FIG. 12 is a photomicrograph (1.1×) of the face of the fabric of Example 1 after the step of selectively patterning the fabric by means of high pressure streams of liquid;
FIG. 13 is a photomicrograph (1.1×) of the face of the fabric of Example 1 after the step of selectively patterning the fabric by means of high pressure streams of liquid and the step of calendering under one ton of pressure per linear inch with a second layer of the untreated fabric of FIG. 11;
FIG. 14 is a photomicrograph (1.1×) of the face of the fabric of Example 2 after the step of selectively patterning the fabric by means of high pressure streams of liquid;
FIG. 15 is a photomicrograph (1.1×) of the face of the fabric of Example 2 after the step of selectively patterning the fabric by means of high pressure streams of liquid and the step of calendering under one ton of pressure per linear inch with a second layer of unpatterned untreated fabric;
FIG. 16 is a photomicrograph (1.1×) of the face of the fabric of Example 3 after the step of selectively patterning the fabric by means of high pressure streams of liquid; and
FIG. 17 is a photomicrograph (1.1×) of the face of the fabric of Example 3 after the step of selectively patterning the fabric by means of high pressure streams of liquid and the step of calendering under one ton of pressure per linear inch with a second layer of patterned fabric.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the accompanying drawings, and initially to FIG. 1, which shows a schematicized side view of an apparatus for generating selectively pattern ribbed fabric wherein an array of liquid jets is placed inside a stencil in the form of a cylinder, which in turn is brought into close proximity to the fabric surface. The stencil is configured to allow the fabric to be patterned to be in the form of a moving web. FIGS. 1 and 2 show a configuration whereby a cylindrical stencil 40 is arranged to accommodate a multiple jet array orifice assembly such as shown at 32 within the stencil 40. In this configuration, orifice assembly 32 preferably comprises an array of jets which extends across the entire width of stencil 40, which in turn extends across the entire width of fabric web 26. Orifice assembly 32 is preferably located in close proximity to the inside surface of cylindrical stencil 40; the outer surface of stencil 40 is preferably located in close proximity to, and perhaps in direct contact with, the surface of fabric web 26. Means, not shown, are provided to achieve smooth rotation of stencil 40 in synchronism with the movement of fabric web 26. This may be achieved, for example, by an appropriate gear train operating on a ring gear which is associated with one or both ends of cylindrical stencil 40.
It is also contemplated that a single or multiple jet array may be used which is made to traverse within cylindrical stencil 40 so that the entire width of fabric web 26 may be treated. Use of such traversing jet or jet array would preferably require incremental movement of fabric web 26, as discussed above.
Where an array of high velocity jets may be individually controlled in response to pattern information, the apparatus shown in FIGS. 3 through 9, may be employed.
FIG. 3 depicts an overall view of an apparatus designed to use a combination manifold/stream forming/stream interrupting apparatus 50, which is depicted in more detail in FIGS. 4 through 9. Pump 8 is used to pump, via suitable conduits 4, 10, a working fluid such as water from a suitable source of supply 2 through an appropriate filter 6 to a high pressure supply duct 52, which in turn supplies water at suitable dynamic pressure (e.g., between 100 p.s.i.g. and 4,000 p.s.i.g.) to the manifold apparatus 50. Also, depicted in FIG. 3 are the conduits 136 for directing the control fluid, for example, slightly pressurized air as supplied from source 130, and valves 134 by which the flow of control fluid may be selectively established or interrupted in response to pattern information supplied by pattern data source 132. As will be explained in greater detail hereinbelow, establishing the flow of control fluid to manifold apparatus 50 via conduits 136, pressurized no higher than approximately one-twentieth of the pressure of the high velocity water, causes an interruption in the flow of high velocity water emanating from manifold apparatus 50. This will prevent the high velocity water from striking the substrate placed against backing member 21. Conversely, interrupting such control fluid flow causes the flow of high velocity water to impact the substrate 26 placed against backing member 21.
Looking to FIG. 4, it may be seen that manifold assembly 50 is comprised of five basic structures: high pressure supply gallery assembly 60 (which is mounted in operable association with high pressure supply duct 52), grooved chamber assembly 70, clamping assembly 90, control fluid conduits 136, and spaced barrier plate assembly 100.
Supply gallery assembly 60 is comprised of an "L"-shaped member, into one leg of which is machined a uniform notch 62 which extends, uninterrupted, along the entire length of the assembly 50. A series of uniformly spaced supply passages 64 are drilled through the side wall 66 of assembly 60 to the corresponding side wall of notch 62, whereby notch 62 may be supplied with high pressure water from high pressure supply duct 52, the side of which may be appropriately milled, drilled, and connected to side wall 66 and the end of respective supply passages 64. Slotted chamber assembly 70 is comprised of an elongate member having an inverted hook-shaped cross-section, and having an extending leg 72 into which have been machined a series of closely spaced parallel slots or grooves 74 each having a width approximately equal to the width of the desired high velocity treatment stream, and, associated with each slot, a series of communicating control fluid passages, shown in greater detail in FIGS. 6 through 9. These control passages are connected to control fluid conduits 136, through which is supplied a flow of low pressure control fluid during those intervals in which the flow of high pressure fluid flowing through slots 74 is to be interrupted.
As shown in FIGS. 6 through 9, the control fluid passages are comprised of a pair of slot intercept passages 76 spaced along the base of each slot and connected to an individual elongate chamber 78 which is aligned with the axis of its respective slot 74. Each slot 74 has associated with it a respective chamber 78, which in turn is connected, via respective individual control supply passages 80, to a respective control fluid conduit 136. In practice, chambers 78 may be made by drilling a passage of the desired length from the barrier plate (104) side of chamber assembly 70, then plugging the exit hole in a manner appropriate to contain the relatively low pressure control fluid.
Grooved chamber assembly 70 is positioned, via clamping assembly 90, within supply gallery assembly 60 so that its "C"-shaped chamber is facing notch 62, thereby forming a high pressure distribution reservoir chamber 84 in which, as depicted in FIGS. 8 and 9, high pressure water enters notch 62 via passages 64, enters reservoir chamber 84, and flows through slots 74 towards the substrate 26. Clamping assembly 90 is provided along its length with jacking screws 92 as well as bolts 94 which serve to securely attach clamping assembly 90 to supply gallery assembly 60 along the side opposite barrier plate assembly 100. It is important to note that the configuration and placement of slotted chamber assembly 70 provides for slots 74 to be entirely covered over the portion of slots closest to reservoir chamber 84, but provides for slots 74 to be uncovered or open over the portion of slots nearest barrier plate assembly 100, and particularly over that portion of the slots 74 opposite and immediately downstream of slot intercept passages 76.
Associated with supply gallery assembly 60 and attached thereto via tapered spacing supports 102 is spaced barrier plate assembly 100, comprising a rigid plate 104 having an edge which is positioned to be just outside the path of the high velocity stream as the stream leaves the confines of slot 74 and exits from the end of chamber assembly 70, and crosses the plane defined by plate 104. To ensure rigidity of plate 104, elongate backing plate 103 is securely attached to the inside surface of plate 104, via screws 105 positioned along the length of plate 104. Screws 106, which thread into threaded holes in spacing supports 102, are used to fix the position of plate 104 following alignment adjustment via threaded alignment bolts 108. Bolts 108 are associated with alignment guide 110 which is, at the time of machine set up, attached to the base of supply gallery assembly 60 via screws 112. By turning bolts 108, precise and reproducible changes in the relative elevation of plate 104, and thereby the clearance between the distal or upstanding edge of plate 104 and the path of the high velocity fluid jet(s), may be made. After the plate 104 is brought into satisfactory alignment relative to slots 74, screws 106 may be tightened and alignment guide 110, with bolts 108, may be removed, thereby fixing the edge of plate 104 in proper relation to the base of slots 74.
FIGS. 6 and 7 depict a fluid jet(s) impacting the substrate 26 perpendicular to the plane of tangency to the surface of support roll 21 at the point of impact; in some cases, however, it may be advantageous to direct the fluid jet(s) at a small angle relative to such plane, in either direction (i.e., either into or along the direction of rotation of roll 21). Generally, such angles (hereinafter referred to as "inclination angles") are about twenty degrees or less, but may be more for some applications.
As depicted in FIG. 7, when no control fluid is flowing through conduit 136 and slot intercept passages 76, highly pressurized water from passages 64 fills high pressure reservoir chamber 84 and is ejected towards substrate 26, via slots 74, in the form of a high velocity stream which passes in close proximity to the distal or upstanding edge of barrier plate 104. The high velocity streams are formed as the high pressure water is forced through the passages formed by covered portions of slots 74; the streams retain substantially the same cross section as they travel along the uncovered portion of slots 74 between supply gallery assembly 60 and barrier plate 104, diverging only slightly as they leave the confines of the slots 74, pass the upstanding portion of barrier plate 104, and strike the substrate 26.
As depicted in FIGS. 7 and 8, when a "no treatment" signal is sent to a valve controlling the flow of control fluid in a given conduit 136, a relatively low pressure control fluid, e.g., air, is made to flow from the selected conduit 136 into the associated slot intercept passages 76 of a given slot 74, and the high velocity stream traveling along that slot is subjected to a force directed to the open side of the slot 74. Absent a counteracting force, this relatively slight pressure introduced by the control fluid causes the selected high velocity stream to leave the confines of the slot 74 and strike the barrier plate rather than the substrate, where its energy is dissipated, leaving the substrate untouched by the energetic stream. In a preferred embodiment of the apparatus, a separate electrically actuated air valve such as the Tomita Tom-Boy JC-300, manufactured by Tomita Co., Ltd., No. 18-16 1 Chome, Ohmorinaka, Ohta-ku, Tokyo, Japan, is associated with each control stream conduit. A valve actuating signal may be generated by conventional computer means, i.e., via an EPROM or from magnetic media, and routed to the respective valves, whereby the high velocity treatment streams may be selectively and intermittently actuated in accordance with supplied pattern data.
FIG. 9 is a section view taken through lines XVII--XVII of FIG. 8, and diagrammatically indicates the effects of control fluid flow in conduits 136. As indicated, low pressure control fluid is flowing in control stream conduits 136 identified as "A" and "C" while no control fluid is flowing in conduits 136 identified as "B" and "D". In conduits "A" and "C", the high velocity jets 120A and 120C, respectively, have been dislodged from the lateral walls of slots 74 and are being deflected on a trajectory which will terminate on the inner surface of barrier plate 104. In contrast, no control fluid is flowing in conduits 136 identified as "B" and "D"; as a consequence, the high velocity jets 120B and 120D, laterally defined by the walls of slots 74, are on a trajectory which will avoid the upstanding edge of barrier plate 104 and terminate on the surface of roll 21, or substrate 26 supported thereby.
Additional information relating to the operation of such a spraying apparatus, including more detailed description of patterning and control functions, can be found in coassigned U.S. Pat. No. 5,080,952, that issued on Jan. 14, 1992, which is incorporated by reference as if fully set forth herein.
Water jet patterns may also be produced by having a raised or embossed support plate or roll that is positioned behind the fabric and treated by an array of water jets. Because of the different surfaces behind the fabric, the pattern will be implemented in the fabric as disclosed by U.S. Pat. No. 4,995,151, which issued on Feb. 26, 1992, which is incorporated by reference as if fully set forth herein.
All of the above methods must use a stream, jet or sheet of water that has some moment of force in the plane of the fabric which will produce the desired filling shift in the patterned area. The range of water pressure is between 100 to 4,000 p.s.i.g. The water pressure necessary to produce the desired filling yarn shift is determined by the moment of force in the plane of the fabric, size of the water jet, and the time the water jet is in contact with the filling yarn.
Referring now to FIG. 10, the next step in the process is to take the patterned fabric 26 and have this patterned fabric processed by a calender mechanism that is generally indicated by numeral 201. The patterned fabric 26 is placed on supply roll 220 and an unpatterned fabric 226 is placed on supply roll 210. Both the patterned fabric 26 and unpatterned fabric 226 are fed into an upper calendering roll 230 and lower calendering roll 232. For good patterning, both the patterned fabric 26 and unpatterned fabric 226 should be ribbed since the surface of the upper calendering roll 230 is smooth as well as the surface of lower calendering roll 232. The moire pattern is made by placing these two layers of ribbed fabric 26 and 226 on top of each other so that the ribs of the upper unpatterned fabric 226 are slightly off-grain in relation to the lower patterned fabric 26. These true moire patterns are produced when the upper unpatterned fabric 226 is sandwiched with the lower patterned fabric 26 and passed through the calender rolls 230 and 232 at high pressure so that wherever the filling yarns cross a moire pattern is produced. The unpatterned fabric 226 may be the lower fabric with the patterned fabric 26 being the upper fabric with no consequential difference. A pressure of 300 to 10,000 pounds per linear inch of fabric between the upper calendering roll 230 and lower calendering roll 232 on the fabrics 26 and 226 causes the ribbed pattern of the patterned fabric 26 to be pressed into the unpatterned fabric 226 and visa-versa. Pressure requirements for producing moire depend on the speed of traverse, temperature, moisture, and types of calender rolls utilized. A typical range for temperature would be between 100 and 450 degrees Fahrenheit. A typical range for moisture would be between 30 and 100 percent relative humidity for natural fibers. Manmade fibers are typically unaffected by relative humidity. The speed of traverse is typically between 10 and 100 feet per minute.
Flattened areas in the ribs reflect more light and create a contrast to unflattened areas. The patterned fabric 26 and unpatterned fabric 226 are then received by take-up rolls 250 and 240, respectively. The crushed and uncrushed portions of either fabric 26 or fabric 226 causes a difference in light reflectance. This creates a wavy or watery effect in both fabrics 26 and 226, respectively. In this case, both fabrics 26 and 226 will have the same moire pattern but they will be mirror images. This technique is especially useful when geometric or floral patterns are used. If both fabrics 26, 226 are patterned, they would be very difficult to keep in register.
Beat repeat patterns may be introduced by having the pick count different in the two layers of fabric 26 and 226 sandwiched together. This may be accomplished by weaving two different pick counts. Another way to accomplish this is to place tension on one of the layers which will reduce the pick count slightly to produce a beating. "Beating" is defined as the pattern developed due to superimposed waves of different frequencies.
Some very beautiful fabrics are produced by creating the moire fabric and then printing the fabric with a colorant such as a dye or pigment. The fabric may, also, be printed first and then water jet patterned and then calendered under pressure to produce a different effect. It may also be water jet patterned, printed and then calendered to produce a novel fabric. Any type of fabric printing may be used including but not limited to rotary screen, flat bed, air brush or engraved roll.
Most fiber types will work with this invention including, but not limited to, polyester, polyamide, acetate, rayon, cotton, and so forth. This invention is not restricted to plain weaves but most woven fabrics will work including, but not limited to, dobby and jacquard woven fabrics. Woven fabrics have warp yarns extending in the warp direction and fill yarns extending in the fill direction. For best results it is the fill yarns that have a ribbed effect. Furthermore, this invention is not restricted to woven fabrics since a moire pattern can be applied to warp knit fabrics. Warp knit fabrics have wales which are a column of loops lying lengthwise in the fabric and correspond to the warp in woven fabrics. Also, warp knit fabrics have courses which are a row of loops or stitches running across a knit fabric corresponding to filing in woven fabrics.
Fabric 226 does not have to be unpatterned and may also be patterned with a different pattern than patterned fabric 26. Also, either fabric 26 or 226 may have a different pick count to produce a beating pattern.
Other methods of applying pressure include high pressure rotary presses and platen presses.
The following examples demonstrate, without intending to be limiting in any way, the method by which fabrics of the present invention have been generated.
EXAMPLE 1
An apparatus similar to that schematically depicted in FIG. 3 was used, in accordance with the following specifications.
Fabric: a faille fabric having a warp comprised of 130 ends/inch of 70 denier bright polyester continuous filament and a fill comprised of 8/1 spun polyester and a pick count of 35. The faille fabric has been woven, prepared, dyed and heatset and has a weight of 5.6 ounces per square yard. A photomicrograph of this fabric is shown by FIG. 11 at 1.1 magnification. This fabric was then patterned with diagonal lines.
Nozzle diameter: 0.017 inches.
Fluid: water, at a pressure of 1,000 p.s.i.g.
Pattern gauge: 20 lines per inch.
Source of pattern data: EPROM, with appropriate associated electronics of conventional design.
Roll: solid, smooth aluminum, rotating at a circumference speed of 10 yards per minute in the same direction as warp yarns in fabric.
In this Example, the entire fabric surface was treated in a series of diagonal spaced lines. The yarns have been laterally displaced where the stream impacted the fabric. A photomicrograph of this treated fabric is shown by FIG. 12 at 1.1 magnification.
This patterned fabric was then sandwiched with an unpatterned piece of the same fabric and run through a BRIEM® calender at eight yards a minute with a temperature of three-hundred and eighty degrees Fahrenheit on the steel roll with a pressure of one ton per linear inch. BRIEM® calenders were formally manufactured by Ernest L. Frank Associates, Inc., 515 Madison Avenue, New York, New York 10022, who is no longer in existence. Both pieces of fabric display the moire pattern shown by the photomicrograph of FIG. 13 at 1.1 magnification.
EXAMPLE 2
An apparatus similar to that schematically depicted in FIG. 3 was used, in accordance with the following specifications.
Fabric: a faille fabric, as described in Example 1, having a warp comprised of 130 ends/inch of 70 denier bright polyester continuous filament and a fill comprised of 8/1 spun polyester and a pick count of 35. The faille fabric has been woven, prepared, dyed and heatset and has a weight of 5.6 ounces per square yard. This fabric was then patterned with linear wavy lines.
Nozzle diameter: 0.017 inches.
Fluid: water, at a pressure of 1,000 p.s.i.g.
Pattern gauge: 20 lines per inch.
Source of pattern data: EPROM, with appropriate associated electronics of conventional design.
Roll: solid, smooth aluminum, rotating at a circumference speed of 10 yards per minute in the same direction as warp yarns in fabric.
In this Example, the entire fabric surface was treated in a series of linear wavy lines. The yarns have been laterally displaced where the stream impacted the fabric. A photomicrograph of this treated fabric is shown by FIG. 14 at 1.1 magnification.
This patterned fabric was then sandwiched with an unpatterned piece of the same fabric and run through a BRIEM® calender at eight yards a minute with a temperature of three-hundred and eighty degrees Fahrenheit on the steel roll with a pressure of one ton per linear inch. Both pieces of fabric display the moire pattern shown by the photomicrograph of FIG. 15 at 1.1 magnification.
EXAMPLE 3
An apparatus similar to that schematically depicted in FIG. 3 was used, in accordance with the following specifications.
Fabric: a faille fabric, as described in Example 1, having a warp comprised of 130 ends/inch of 70 denier bright polyester continuous filament and a fill comprised of 8/1 spun polyester and a pick count of 35. The faille fabric has been woven, prepared, dyed and heatset and has a weight of 5.6 ounces per square yard. This fabric was then patterned with a floral pattern.
Nozzle diameter: 0.017 inches.
Fluid: water, at a pressure of 1000 p.s.i.g.
Pattern gauge: 20 lines per inch.
Source of pattern data: EPROM, with appropriate associated electronics of conventional design.
Roll: solid, smooth aluminum, rotating at a circumference speed of 10 yards per minute in the same direction as warp yarns in fabric.
In this Example, the entire fabric surface was treated in a floral pattern. The yarns have been laterally displaced where the stream impacted the fabric. A photomicrograph of this treated fabric is shown by FIG. 16 at 1.1 magnification. This patterned fabric was then sandwiched with another patterned piece of the same fabric and run through a BRIEM® calender at eight yards a minute with a temperature of three-hundred and eighty degrees Fahrenheit on the steel roll with a pressure of one ton per linear inch. Both pieces of fabric display the moire pattern shown by the photomicrograph of FIG. 17 at 1.1 magnification.
As this invention may be embodied in several forms without departing from the spirit or essential character thereof, the embodiments presented herein are intended to be illustrative and not descriptive. The scope of the invention is intended to be defined by the following appended claims, rather than any descriptive matter hereinabove, and all embodiments of the invention which fall within the meaning and range of equivalency of such claims are, therefore, intended to be embraced by such claims. | An apparatus and method for creation of moire fabric. This can be achieved by placing a first piece of fabric against a support member and directing at least one stream of fluid at the surface of said first piece of fabric to provide lateral yarn displacement. Then delivering said stream at a peak dynamic pressure in excess of about 300 p.s.i.g. and less than 4,000 p.s.i.g. and selectively interrupting and re-establishing contact between said stream and said surface in accordance with pattern information in order to pattern said first piece of fabric. This is followed by combining said patterned first piece of fabric with an unpatterned second piece of fabric in overlapping relationship and applying pressure by means of calender rolls having smooth surfaces to said combination of said first piece of patterned fabric and said second piece of unpatterned fabric. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of e-marketing and more particularly to the field of pay-per-click marketing.
[0003] 2. Description of the Related Art
[0004] The Internet has revolutionized the manner in which goods and services are marketed both locally and globally. The mere collection of a few electronic documents can represent a complex storefront when presented to the global computing community over the World Wide Web as a Web site. Interestingly, unlike the conventional sale of goods and services through a brick-and-mortar operation, the pages of a Web site can serve the purpose both of advertising and marketing medium and storefront. To wit, the content of a Web page can serve as a way to advertise goods and services, while also offering those same goods and services for sale responsive to a few mouse clicks.
[0005] Given the unique role of the Internet in the sale and marketing of goods and services, fundamental changes in traditional advertising and marketing have become apparent. In particular, e-marketing, unlike traditional marketing, involves a grass roots component. Search engines have facilitated the development of this grass roots component in which consumers discover the presence of a Web site through the postings of third parties. In the search engine paradigm, references to Web sites are cataloged and presented to consumers on demand in response to keyword searches.
[0006] The sheer volume of content indexed by the typical search engine can result in the individual Web sites becoming lost in the mix. Similar to a phone book entry among a sea of phone book entries, for many Web sites, the indexing of the Web site by the search engine can be as ineffective as not being indexed at all unless the Web site appears in the first few entries of a results list produced by the search engine. Accordingly, many Web sites rely on more advanced, fee-based, Internet based grass roots marketing techniques to advance the awareness of a Web site.
[0007] Specifically, whereas the grass roots nature of search engine linkage to a Web site involves no obligation on the part of the Web site owner/operator, other grass roots e-marketing techniques require the Web site operator to pay a fee. The presence of a fee necessarily reduces the number of marketed Web sites resulting in a higher level of visibility for a Web site. Once such fee-based, Internet grass roots marketing technique is pay-per-click marketing. In pay-per-click marketing, text or an image can be embedded in one Web site, however, when selected, the text or image can link to a second Web site. The first Web site is the host Web site and the second Web site is the marketed Web site.
[0008] In the pay-per-click model, whenever a viewer selects the text or image linking to the marketed Web site, the host Web site is compensated for the “click through”. In this way, the marketed Web site need only pay the host Web site for a successful attempt at grass roots marketing. Notwithstanding, the pay-per-click model presupposes that each click through is legitimate in nature. However, it is well-known that fraud has become prevalent throughout the pay-per-click world. Specifically, it is not uncommon for a host Web site to automate the periodic selection of a pay-per-click link in order to enhance revenues (fraudulently) to the host Web site. Likewise, it is also not uncommon for a competitor to the operator of the marketed Web site to automate the selection of a pay-per-click link in order to unnecessarily increase the marketing costs for the pay-per-click for the operator of the marketed Web site.
BRIEF SUMMARY OF THE INVENTION
[0009] Embodiments of the present invention address deficiencies of the art in respect to pay-per-click processing and provide a novel and non-obvious method, system and computer program product for pay-per-click fraud prevention. In one embodiment, a pay-per-click data processing system can include a pay-per-click engine configured for coupling to a host site and a marketed site. The system of the embodiment also can include link randomization logic coupled to the pay-per-click engine. The logic can include program code enabled to modify a link address for a link disposed in the host site and referencing the marketed site. The pay-per-click engine, in turn, can include program code enabled to reject click throughs for the link which do not reference the modified link address.
[0010] The host site and marketed site can include a host Web site and a marketed Web site. Also, the link address can be a uniform resource locator (URL). The system of the embodiment further can include a clock coupled to the link randomizer. Consequently, the program code of the link randomization logic can be further enabled to modify the link address responsive to a time indicated by the clock. In one aspect of the embodiment, the program code of the link randomization logic can be further enabled to modify the link address to include a random value responsive to a time indicated by the clock.
[0011] Optionally, the system can include a clock coupled to the link randomizer. The program code of the link randomization logic further can be enabled to modify the link address in response to a time indicated by the clock. The modification can include a random value provided by the marketed site, a random number seed provided by the marketed site, and random number algorithm provided by the marketed site. As another option, the system additionally can include a counter enabled to count each click through of the link from a single source. As a result, the pay-per-click engine further can include program code enabled to challenge the single source of the click through to establish a human presence responsive to the counter crossing a threshold value.
[0012] In another embodiment, a fraud prevention method for a pay-per-click data processing system can be provided. The method can include receiving a click through for a link in a host site which references a marketed site. The method also can include identifying a link address for the link in the click through. The method yet further can include comparing the identified link address to a modified link address recorded for an actual link address for the marketed site. Finally, the method can include quashing the click through if the identified link address is not the modified link address. Conversely, the method can include redirecting the click through to the marketed site if the identified link address is the modified link address.
[0013] Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0014] The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:
[0015] FIG. 1 is a schematic illustration of a pay-per-click data processing system configured with pay-per-click fraud protection;
[0016] FIG. 2 is a flow chart illustrating a process for randomly assigning a link address for a pay-per-click link in the system of FIG. 1 ; and,
[0017] FIG. 3 is a flow chart illustrating a pay-per-click fraud protection method.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Embodiments of the present invention provide a method, system and computer program product for pay-per-click fraud protection. In accordance with an embodiment of the present invention, a link associated with a link address referencing a marketed site can be disposed in a page of a host site. The associated link address can resolve directly to the marketed site. The link address of the disposed link, however, can be periodically altered, for example in a randomized fashion, to produce a temporary, modified link address which does not directly resolve to the marketed site. Optionally, the marketed site can supply one or more elements necessary to produce the temporary, modified link, for instance a random number, a seed for a random number generator, or a formula for producing a random number necessary to generate a randomized form of disposed link.
[0019] In this regard, intermediate pay-per-click logic can process the selection of the link to translate the temporary, modified link address into the associated link address which resolves directly to the marketed site. The intermediate pay-per-click logic further can quash attempts to fraudulently submit a simulated selection of the link using a link address which differs from the temporary, modified link address. Finally, a table correlating the temporary, modified link address to the associated link address can be maintained to facilitate the operation of the intermediate pay-per-click logic for legitimate attempts to submit a selection of the link. Also, as an optional, additional measure, a counter can be implemented to count a number of times a link is selected from the same site. When the counter exceeds a threshold value, the linking party can be challenged to validate the absence of a bot, such as recognizing text embedded in an image.
[0020] In more particular illustration, FIG. 1 is a schematic illustration of a pay-per-click data processing system configured with pay-per-click fraud protection. The system can include a pay-per-click engine 140 in communication with a marketed site 150 accessible at a first content server 130 . The pay-per-click engine 140 can be disposed in or communicatively coupled to a host site 160 accessible at a second content server 120 . Notably, the host site 160 can include a link 170 associated with a link address of the marketed site 150 such that the link address can resolve to the marketed site 150 in the first content server 130 .
[0021] Link randomization logic 200 coupled to the pay-per-click engine 140 can include program code enabled to change the link address of the link 170 to a modified address which does not directly resolve to the marketed site 150 in the first content server 130 . The program code of the link randomization logic 200 can change the link address of the link 170 from time to time according to a coupled clock 180 . For example, when a threshold period of time has elapsed as indicated by the clock 180 , the program code of the link randomization logic 200 can be enabled to produce a random modification to the link address of the link 170 . The correlation between the produced random modification and the link address of the link 170 can be maintained in a translation table 190 .
[0022] Optionally, the random modification can be produced based upon a randomization algorithm provided by the marketed site 150 . Alternatively, the random modification can be produced based upon a random number or numbers provided by the marketed site 150 . As yet another alternative, the random modification can be produced based upon a seed provided by the marketed site 150 for use in a random number generator. The marketed site 150 can be prompted when it is necessary to produce the random modification to the link address of the link 170 , or the marketed site 150 can provide the elements necessary for randomization pro-actively.
[0023] In operation, responsive to the receipt of a submission of the link 170 , the program code of the link randomization logic 200 can receive a link address associated with the link 170 . The program code of the link randomization logic 200 can be enabled to access a translation table 190 to determine whether a translation is available for the link address to resolve directly to the marketed site 150 . If not, the program code of the link randomization logic 200 can consider the submission to fraudulent and the submission can be quashed. Otherwise, the program code of the link randomization logic 200 , deeming the submission to be legitimate, can translate the link address and can redirect the submission to the marketed site 150 in the first content server 130 . Additionally, the pay-per-click engine 140 can record the click-through for the legitimate submission.
[0024] Optionally, a counter can be established for the link 170 . Each time the link 170 is selected from a particular site, the counter can be incremented. When the counter crosses a threshold value, the submission can be considered fraudulent and a prompt can be issued for the linking party challenging the linking party to provide a human response to a computer generated stimuli in order to prove the presence of a human. Examples, include well-known techniques such as recognizing text disposed within an image or responding to a logic question.
[0025] In further illustration, FIG. 2 is a flow chart illustrating a process for randomly assigning a link address for a pay-per-click link in the system of FIG. 1 . Beginning in block 205 , a time can be retrieved and in block 210 it can be determined whether a threshold amount of time has elapsed to trigger a modification to a link address for a link to a marketed site. It is to be recognized by the skilled artisan, however, that the invention is not limited to the lapsing of time and other time based determinations are within the scope of the invention. Such other time based determinations can include the occurrence of a particular time.
[0026] In block 215 , once the time threshold is encountered, the link address for a link disposed in a host site can be modified. The modification can include, for example, a modified portion of the uniform resource locator (URL) associated with the link. For instance, where the actual link URL referenced within the link is “www.marketedsite.com/pay-per-click-engine”, the modified URL can be randomly assigned as a function of the actual link URL to “www.marketedsite1.com/pay-per-click-engine”. In block 220 , a translation can be recorded for the actual link URL and the modified URL. Finally, in block 225 the link with the modified URL can be published to the host site.
[0027] Once a link in the host site has been published, the pay-per-click engine referenced by the link address of the link can be process link submissions, whether fraudulent or legitimate. In illustration, referring to FIG. 3 , in block 230 a click through can be received from the host site in association with a link disposed in the host site. In block 235 , the link address for the link can be retrieved for processing. In decision block 240 , it can be determined whether a recorded translation for the link address exists and whether the link address is legitimate. If not, in block 245 the click through can be rejected as illegitimate.
[0028] In decision block 240 , if it is determined that the click through is legitimate, in block 250 the link address for the click through submission can be translated to an address which resolves to a corresponding marketed site. In block 255 , the click through can be recorded to account for a pay-per-click. Finally, in block 260 the click through can be redirected to the corresponding marketed site according to the translated address provided in block 250 .
[0029] Embodiments of the invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, and the like. Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system.
[0030] For the purposes of this description, a computer-usable or computer readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk—read only memory (CD-ROM), compact disk—read/write (CD-R/W) and DVD.
[0031] A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters. | Embodiments of the invention provide a fraud prevention method for a pay-per-click data processing system. The method can include receiving a click through for a link in a host site which references a marketed site. The method also can include identifying a link address for the link in the click through. The method yet further can include comparing the identified link address to a modified link address recorded for an actual link address for the marketed site. Finally, the method can include quashing the click through if the identified link address is not the modified link address. Conversely, the method can include redirecting the click through to the marketed site if the identified link address is the modified link address. | 6 |
BACKGROUND OF THE INVENTION
This invention is a continuation in part of co-pending U.S. application Ser. No. 07/492,533 for "Improvements in the Radiographic Analysis of Bones" filed Mar. 12, 1990 now abandoned. U.S. application Ser. No. 07/492,533 was filed claiming a priority date under 35 U.S.C. §119 for West German utility model application G8903054.0 of Mar. 10, 1989 and U.K. Pat. application 8921300.3 of Sep. 20, 1989.
FIELD OF THE INVENTION
This invention relates to an aid for use in radiographic analysis of bones and particularly to a device used to aid the reduction of a bone fracture or produce a precise change in alignment in a surgically divided bone. The aid is particularly useful during procedures in an operating theatre but may also be used in an out-patient department.
Bone fractures are currently reduced by eye and the overall bony alignment confirmed by radiographic analysis using a conventional radiograph. This results in the necessity of breaching the sterile field in order to place the radiographic cassette in the correct position and to retrieve it after the exposure has been made. The whole procedure may take upwards of 10 minutes and may require repeating if the correct alignment of the bone has not been obtained. If the alignment is not correct the bone must be reset with consequent distress to the patient and an increase in the use of hospital resources.
It is extremely important to achieve good bone alignment not only to ensure that the broken bone is straight but also to ensure that the axes of joints at the ends of the bone are aligned. For example, in the case of a leg broken between the knee and the ankle, it is essential to ensure that the axis of the knee joint is parallel to the axis of the ankle joint, for otherwise the patient will have difficulty in walking properly. It may also be necessary to ensure that the joint centers are on the principal bone axis or are offset by a predetermined amount from that axis.
Currently mobile x-ray image intensification units use a coupled television system to visualize the bone in real time, but the field of view is not large enough to view the whole of the bone and so get an impression of the alignment. Typically an image of about six inches in diameter is obtained and this is not sufficiently large to obtain an accurate assessment of the overall alignment. Also there is some distortion of the image at the edge of the field of view which further hampers assessment of bone alignment.
The invention is an aid to be used in real time conjunction with an image intensification unit and is especially useful in the setting of long bone fractures and in corrective surgery of the long bones such as the humerus, radius, and ulna, femur and tibia and fibula.
In order to check alignment it is necessary to move the image intensification unit from one end of the bone to the other but, in the absence of a suitable guide it is difficult to check the alignment of the bone.
PRIOR ART OF THE INVENTION
Devices have been proposed for use in x-ray photography in which features of the human anatomy are photographed against a grid of x-ray opaque material. The grid is inserted between the x-ray source and film, and the resulting exposure shows a shadow of the tissue against a dimensionally accurate grid. Such photographs are used for comparative reference, and diagnostic purposes. These devices have not, however, been proposed for use in real time fluoroscopy where the alignment of the bone is checked in real time against a guide.
U.S. Pat. No. 2,344,824--Landis et al. discloses a fine marking grid for use with an x-ray photographic plate and intended for use in a method of detecting misalignment of bone structure. The disclosed method permits a comparison of normally symmetrical parts of a human bone structure.
U.S. Pat. No. 4,918,715--Krupnick et al. discloses a flexible substrate having an x-ray opaque grid and for use in marking the exterior of a patient's body prior to invasive surgery. The substrate deforms to closely match the body contours and is removed prior to surgery.
U.S. Pat. No. 3,171,959--Kozek et al. discloses a marking grid having a plurality of spaced x-ray opaque parallel lines for providing measurements and for use with an x-ray photographic device.
A particular feature of prior art measuring devices is that none are suitable for use in real time in extending the field of view of mobile x-ray image intensification unit.
Furthermore none of the prior art devices known to the applicants is for use in procedures performed in operating theatres, and none are specifically for orthopedic or bone fracture applications.
SUMMARY OF THE INVENTION
According to the invention there is provided a hand portable aid for use in the real time radiographic analysis of bones, the aid comprising a substantially rigid sheet of x-ray pervious material at least as large as the bone or bones to be analyzed and carrying a radio-opaque marker or other x-ray attenuating material against which alignment of the bone may be checked. Preferably the sheet is of carbon fiber, polycarbonate or polymethyl methacrylate (PERSPEX) or other low attenuating material, and the marker is in the form of several mutually perpendicular lines of high attenuating material.
It is essential that the aid be substantially rigid for otherwise it could not provide a reference for checking alignment. The flexible sheet of Krupnick et al. is wholly unsuitable. The aid must be sufficiently rigid to resist deformation as the patient is moved about on the operating table.
Whilst it is essential that the aid is at least as large as the bone or bones to be analyzed. It is important that the aid is not so large that it cannot be manipulated by hand into approximately the correct position.
In a preferred embodiment the marker comprises a grid of discrete lead wires or of similar material having a high atomic number. The radio-opaque marker is preferably incorporated within the sheet for protection and to give a device which is easily cleaned and sterilized.
In one preferred embodiment the aid is approximately 600 mm by 300 mm and approximately 4-5 mm thick. Lead wires of approximately 1 mm thickness are preferred.
Since the aid is for use in real time surgery and thus within the sterile field, it is essential that it be capable of sterilization by normal techniques and is preferably sufficiently robust to be capable of repeated sterilization.
The invention also provides a method of using the aid in preparation of a bone or bones for surgery or treatment, the method comprising the steps of placing the bone or bones over the aid, providing a real time x-ray image of the bone or bones against the aid and comparing the relative position of bone or bones and marker.
In a preferred embodiment the aid includes a radio-opaque grid and, when used for bone alignment, the method further includes the step of adjusting the position of the aid until the aid is approximately aligned with the bone and adjusting the position of the bone until the image of the bone adopts a desired alignment with the grid. The bone may then be set using any conventional technique, such as plaster, plate and screws, intra medullary nail or external fixator.
In addition to being used in alignment of bone fractures, the device may be used in conjunction with a radio-opaque rule for accurate measurement of bone length; as a means of obtaining an accurate comparison between a pair of bones, and in conjunction with a radio-opaque protractor as a means of designing osteotomies. Two identical aids according to the invention may be used one above and one below the bone to ensure perpendicularity of the x-ray beam with respect to a particular plane through the bone. Alternatively perpendicularity may be checked by the use of two spaced sets of wires in a single perspex sheet to be used either above or below the bone.
In another aspect the aid may be used to check or fix the alignment of the joints at the ends of a bone. In particular both the bone and the axes of respective joints may be aligned with the grid.
BRIEF DESCRIPTION OF THE DRAWING
Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only with reference to the accompanying drawings which:
FIG. 1a is a plan view of a preferred embodiment of the device;
FIG. 1b is an elevation of FIG. 1a;
FIG. 1c is an end view of FIG. 1a.
FIG. 2a is a perspective view of an alternative form of the device;
FIG. 2b is a transverse section through FIG. 2a line 2--2;
FIG. 2c is an enlarged view of sheet substrate 5 without the existance of wire 3.
FIG. 3a is a plan view of the aid in use;
FIG. 3b is an elevation of the aid in use.
FIG. 4a is an image of a knee joint and the aid;
FIG. 4b is an image of an ankle joint in one orientation and the aid;
FIG. 4c is an image of an ankle joint in another orientation and the aid.
FIG. 5a is a plan view of a rule for use with the aid of FIGS. 1 and 2.;
FIG. 5b is an elevation of the rule of FIG. 5a;
FIG. 5c is an end view of the rule of FIG. 5a.
FIG. 6 is an image of a bone showing also the aid of the invention and the rule of FIGS. 5a-c.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1a-c of the drawings there is shown a device 1 comprising a grid of lead wires 2,3 contained within a clear substrate 4 such as polycarbonate or polymethyl methacrylate.
In the embodiment of FIG. 2, the grid comprises a number of wires 2,3 of round section housed within recesses between two sheets of substrate 5,6; the wires stop short of the edges of the sheets 5,6 as shown. The wires may be laid in slots milled in the surface of the substrate and sealed therein. The sheets 5,6 are sealed to each other so that the aid may be readily cleaned and sterilized after use without the risk of damaging the grid.
Since the device is used in surgery and thus within the sterile field it is most important that it be suitable for sterilizing in an autoclave.
The grid may be formed of strips of lead or of any other suitable radio-opaque material which provides sufficiently dense and dark lines. Marks, such as the notches 7 may be provided as an alternative to additional longitudinal threads which would increase the manufacturing cost and might obscure the bone image in use.
The number and extent of transverse wires may be chosen to suit the size and type of bone being set. A number of such devices with differing grid configurations may be made available for use. In the example of FIG. 1a the aid measures 600×300×4 mm with the longitudinal wire and outer transverse wires extending to the periphery of the aid. The outer transverse wires are 70 mm from the respective ends and the intermediate wires are 50 mm apart and symmetrical about the center line as shown. The intermediate wires may be closer if desired, for example 25 mm apart.
The outer transverse wires define reference lines between which should lie the bone or bones to be imaged; these reference lines should preferably extend across the full width of the aid. The intermediate wires are in the preferred embodiment about 22 mm long, but should in any event be sufficiently long to extend the full diameter of the real time T.V. image.
Longer and wider grids may be used for determination of the mechanical axis of the limb and to perform comparisons between a pair of limbs.
A narrow perspex strip containing one longitudinal wire or a set comprising a calibrated protractor of radio-opaque material may be placed on the aid to position and design osteotomies as will be further described below.
Use of the aid is now described with reference to a broken leg. The aid 1 is placed below the leg 8 and aligned approximately with the broken bone as illustrated in FIGS. 3a and 3b.
The image intensification is used to image the knee joint, as illustrated in FIG. 4a, and nearest reference line 11 on the aid is moved, under fluoroscopy, so that it passes through the center of the knee joint.
The image intensification is tracked linearly down the leg and may be used to check the fracture site in passing. The ankle joint is then imaged as illustrated in FIG. 4b. In a normal leg the axis of the knee joint is parallel to the axis of the ankle joint, but in a broken leg the ankle axis may not be aligned with the transverse grid wires--FIG. 4b illustrates such a situation, the ankle axis being shown approximately by dotted line 13.
To correct alignment, the ankle joint is manipulated, as illustrated in FIG. 4c, until the joint axis 13 is parallel to the transverse grid lines and thus parallel to the knee joint axis. The grid center line should pass through the ankle center line thus conforming that the ankle joint has been restored to its original relative position. The broken bone may then be set using any desired method.
In some cases the joint center lines may not coincide in which case the aid may be used to determine the offset of a symmetrical bone, and thereafter be used to set the corresponding broken bone with the same offset. In the case described above the unbroken leg may be used to provide a reference prior to using the aid in setting the broken leg.
FIGS. 5a-c illustrate a radio-opaque rule 14 used in osteotomies. The rule comprises a flat strip of material containing a radio-opaque line 15 and may be made in the same manner as the aid described above. The rule may typically be 300 mm×25 mm×4 mm and contain a lead wire of 1 mm in diameter.
FIG. 6 illustrates use of the rule in designing an osteotomy where a bone is to be cut in a precise and predetermined manner. The rule 14 is represented by the dotted outline and may be secured to the aid 1 in any suitable fashion to form a precise angle. The surgeon can thus cut a precise wedge of bone along lines defined by the rule and the aid and as seen on the T.V. image. | A hand portable aid for use in the real time radiographic analysis of bones and comprising a substantially rigid sheet of x-ray pervious material at least as large as the bone and carrying a radio-opaque marker against which alignment of the bone may be checked. | 0 |
U.S. GOVERNMENT RIGHTS
This invention was made with government support under the terms of DE-FC26-04NT42280 awarded by the Department of Energy. The government may have certain rights in this invention.
TECHNICAL FIELD
The present disclosure relates to a thermoelectric system for generating electrical power. In particular, the present disclosure relates to thermoelectric devices disposed within the head of an internal combustion engine.
BACKGROUND
Internal combustion engines have become an integral component of many cultures throughout the world, providing a means of transportation and power generation while improving people's work productivity, generally. Over the years, researchers have improved many aspects of engine technology. Despite these many advances, unfortunately, engines only operate at about 50% efficiency or lower.
Poor engine efficiency is largely attributable to thermal energy lost during the combustion process. Much of this waste heat is conducted through various engine components and transferred to the environment, providing no useful work whatsoever.
In an effort to improve the efficiency of combustion engines, researchers have developed ways to convert some of the waste heat into useful energy. For example, some researchers have converted waste heat into useful electrical energy that can be used to supplement a portion of the engine's electrical loads.
One such way is disclosed in U.S. Pat. No. 6,029,620 to Zinke (“Zinke”). Zinke discloses an engine block containing thermoelectric materials that generate a direct current during operation and, in so doing, provides for at least some of the necessary engine cooling requirements and for at least some of the electric power requirements. Zinke discloses manufacturing internal combustion engines out of thermocouple-type materials. Zinke also discloses attaching thermoelectric modules to the exterior of an engine for minimizing the redesign of internal engine components.
Thermoelectric devices may either convert electrical energy into thermal energy or thermal energy into electrical energy. Early 19th century scientist Thomas Seebeck discovered the phenomenon of placing a temperature gradient across the junctions of two dissimilar conductors resulted in the flow of electrical current.
The engines disclosed in Zinke, unfortunately, fail in several respects. First, thermoelectric materials do not generally share the same material characteristics as the iron alloys used in engine block and head castings. As a result, an engine composed entirely of thermoelectric materials may exceed design limitations or fail to be robust enough for practical use. Additionally, the cost of thermoelectric materials is generally considerably higher than those of iron alloys. As a result, an engine composed entirely of thermoelectric materials would be prohibitively expensive.
Furthermore, Zinke fails to disclose precise locations for placing these thermoelectric materials. Zinke simply discloses either making an engine entirely out of thermoelectric materials or, in the alternative, generally attaching thermoelectric materials to the engine block. Simply attaching thermoelectric materials to an engine block, without anything further, fails to provide a practical solution for recovering waste heat.
The present disclosure is aimed at overcoming one or more of the shortcomings set forth above.
SUMMARY OF THE INVENTION
In one particular embodiment, an internal combustion engine is provided. The engine comprises a block, a head, a piston, a combustion chamber defined by the block, the piston, and the head, and at least one thermoelectric device positioned between the combustion chamber and the head. In this particular embodiment, the thermoelectric device is in direct contact with the combustion chamber.
In another particular embodiment, a cylinder head configured to sit atop a cylinder bank of an internal combustion engine is provided. The cylinder head comprises a cooling channel configured to receive cooling fluid, valve seats adapted to receive intake valves and exhaust valves, and thermoelectric devices positioned around the valve seats.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic illustration of a thermoelectric device arrangement according to an exemplary embodiment of the disclosure;
FIG. 2 is another diagrammatic illustration of a thermoelectric device arrangement according to an exemplary embodiment of the disclosure;
FIG. 3 is a cross-sectional view of the diagrammatic illustration of FIG. 2 ; and
FIG. 4 is a cross-sectional view of a thermoelectric device according to one particular embodiment of the disclosure.
DETAILED DESCRIPTION
FIG. 1 provides a diagrammatic illustration of thermoelectric devices 10 positioned within a cylinder head 1 of an internal combustion engine.
In the particular embodiment of FIG. 1 , the engine is a reciprocating-piston internal combustion engine, with piston 60 that reciprocates within a cylinder 64 formed within engine block 2 . A combustion chamber 50 is defined by topside 63 of piston 60 , bottom side of head 1 , and cylinder 64 formed within engine block 2 . Combustion of a fuel and air mixture occurs within combustion chamber 50 , generating high temperatures as a result of the heat release associated with the combustion. Much of this heat is thermally transferred to head 1 , piston 60 , and block 2 .
The heat transferred to these components generally performs no useful work and consequently decreases the overall efficiency of the engine. In an effort to improve this efficiency, thermoelectric devices 10 are arranged within cylinder head 1 . These thermoelectric devices 10 convert some of this wasted heat energy into useful electrical energy, which can later be used to supplement the engine's electrical loads, for example.
As previously mentioned, electrical energy is produced from thermal energy under the phenomenon known as the Seebeck effect.
When a temperature gradient is imposed on a conductor under open circuit conditions—that is, no current is allowed to flow—a steady-state potential difference between the high- and low-temperature regions is created. In a closed circuit, on the other hand, electrical current will flow as long as the temperature gradient is maintained. The power density produced by this temperature gradient is proportional to the temperature gradient and defined by the following equation:
Q
″
=
λ
Δ
T
L
Q″ defines power density, or power per unit area. L defines the distance between hot surface 11 and cold surface 12 (see FIG. 4 ) and A defines the thermal conductivity of thermoelectric device 10 . As can be seen, the larger the temperature gradient, the larger the power generated.
This disclosure proposes positioning thermoelectric devices 10 within head 1 of engine so that devices 10 are located between two areas with a large thermal gradient, such as between engine coolant 40 and combustion chamber 50 . Between these locations, a large temperature gradient is generally observed. In some instances, this temperature gradient may be as high as 650° C.
The Figure of Merit, ZT, of a material at a given temperature T is used to describe the material's performance or effectiveness when used in thermoelectric device 10 . The Figure of Merit is defined by the following equation:
Z
T
=
S
2
T
R
K
S defines the Seebeck coefficient of thermoelectric device 10 , R defines the electrical resistance of thermoelectric device 10 , K defines the thermal conductance of the material, and T defines the temperature. The higher the Figure of Merit, the better the performance of thermoelectric device 10 . In some embodiments of the present disclosure, the Figure of Merit is at least three. Nanostructured boron carbide, for example, is a material that exhibits a Figure of Merit of at least three and at the temperatures commonly associated with internal combustion engine operation.
Now referring to FIG. 4 , a particular embodiment of thermoelectric device 10 is shown. The reader should appreciate that the present disclosure is not limited to the particular thermoelectric device 10 shown in FIGS. 1-4 . Instead, one skilled in the art would understand that several different types of thermoelectric devices 10 might alternatively be used to carry out the invention of the present disclosure.
The particular thermoelectric device 10 of FIGS. 1-4 comprises two ceramic substrates that serve as a foundation and electrical insulation for P-type semiconductors 14 and N-type semiconductors 13 . These semiconductors 13 and 14 are connected electrically in series and thermally in parallel between the ceramics. The ceramic substrates also serve as insulation between the internal electrical elements. In this particular embodiment, a heat sink is in contact with hot side 11 and a cooler surface is in contact with cold side 12 . An electrically conductive material—such as conducting pads attached to P-type semiconductors 14 and N-type semiconductors 13 —maintain electrical connections inside device 10 . Solder or any other known fixing technique may be used at the connection joints to enhance the electrical connections and hold device 10 together.
In some embodiments, P-type semiconductors 14 comprise compounds or boron and/or silicon. N-type semiconductors 13 , on the other hand, may comprise SiC or SiGe, for example.
In some embodiments, electrical leads 70 to the device 10 are attached to pads on the hot side 11 of device 10 . Leads 70 may then be connected to a DC battery, DC loads, or a DC-AC inverter for powering any AC loads, for example. The reader should appreciate that as electrical power is generated, its application may go towards any useful means envisioned by one skilled in the art and is not limited to those listed above.
The particular embodiment of FIG. 1 depicts thermoelectric devices 10 positioned within head 1 so that a hot side 11 of thermoelectric devices 10 faces combustion chamber 50 . The highest temperatures within an engine generally occur within combustion chamber 50 , and can be as high as 750° C. or higher.
Additionally and as further depicted in the particular embodiment of FIG. 1 , cold side 12 of thermoelectric device 10 faces away from combustion chamber 50 and faces towards cooling channel 40 . In one particular embodiment, the cooling fluid in coolant channel 40 is engine jacket water that was just previously cooled by an engine cooler, such as a radiator. Because the electrical power generated by thermoelectric devices 10 is proportional to the temperature gradient, it is desirable to configure the engine's coolant system so that a cooler portion of the coolant flows through channel 40 .
In the particular embodiment of FIG. 1 , thermoelectric device 10 is separated from coolant channel 40 by metallic interface 42 , which in this embodiment is integrally formed with head 1 . Metallic interface 42 provides a high-pressure boundary separating combustion chamber 50 from channel 40 while at the same time providing a barrier to prevent thermoelectric device 10 from directly contacting coolant within channel 40 .
In some instances, head 1 may be manufactured from a casting process. Cavities may be formed during the casting process to accommodate thermoelectric devices 10 . Alternatively, cavities may be machined within head 1 to accommodate thermoelectric devices 10 . Thermoelectric devices 10 may then be placed within the cavities so that devices 10 directly contact the combustion gases within combustion chamber 50 . The reader should appreciate that the precise method of manufacturing these cavities is not germane to the disclosed embodiments and that one skilled in the art would understand that several methods might exist for manufacturing head 1 with cavities for accommodating devices 10 .
During the manufacture of cylinder head 1 , metallic interface 10 may also be formed integral with head 1 so that a high-pressure boundary exists to isolate combustion chamber 50 —and thermoelectric devices 10 —from coolant channel 40 .
Now referring to FIG. 2 , FIG. 2 provides a diagrammatic illustration of thermoelectric devices 10 positioned within an engine's head 1 . The particular embodiment of FIG. 2 depicts four thermoelectric devices 10 positioned around two intake valves 20 and two exhaust valves 25 . Many engines have two intake valves 20 and two exhaust valves 25 per cylinder 64 . Although the particular embodiment of FIG. 2 depicts two intake valves 20 and two exhaust valves 25 per cylinder 64 , the reader should appreciate that the present disclosure applies to engines with other valve configurations. In addition, although intake valves 20 and exhaust valves 25 are shown as having similar diameters, the reader should appreciate that many internal combustion engines have intake valves 20 and exhaust valves 25 with varying diameters and that the present disclosure would apply to these engines, as well.
In the particular embodiment disclosed in FIG. 2 , thermoelectric devices 10 have a general “T” shape. This particular shape—when oriented according to FIG. 2 —increases the surface area of thermoelectric devices 10 that is in contact with combustion chamber 50 . This may allow for devices 10 to convert more waste heat to electrical energy. Fuel injector 30 (or spark plug) may be centrally located within cylinder 64 , which when in the presence of two intake valves 20 and two exhaust valves 25 , justifies the T-shape nature of the four thermoelectric devices 10 .
Now referring to FIG. 3 , FIG. 3 provides a cross-sectional view-along line I-I—of part of engine head 1 that is depicted in FIG. 2 . As can be seen in the particular embodiment of FIG. 3 , thermoelectric devices 10 have a hot side 11 and a cold side 12 . In this particular embodiment, hot side 11 is in direct contact with combustion chamber 50 while cold side 12 faces cooling chamber 40 . As can further be seen, a metallic interface 42 exists to separate cooling channel 40 from device 10 . In the particular embodiment of FIG. 3 , metallic interface 42 is integrally formed with head 1 .
Now referring to FIG. 4 , a particular embodiment of thermoelectric device 10 is shown.
A typical thermoelectric device 10 comprises of two ceramic substrates that serve as a foundation and electrical insulation for P-type 14 and N-type 13 semiconductors. Semiconductors 14 and 13 are connected electrically in series and thermally in parallel between the ceramics. The ceramic substrates may also serve as insulation between the internal electrical elements and a heat sink that may be in contact with hot side 11 as well as a cooler object against cold side 12 . The electrical connections between P-type 14 and N-type 13 semiconductors may be achieved by the use of metallic leads 70 —or tabs—which may comprise nickel or chromium. Nickel, for example, is a material with suitable conductivity and oxidation resistance.
In some particular embodiments, metallic leads 70 may be connected to the ends of each semiconductor 13 or 14 leg by a conductive material that is applied at room temperature. When set, the conductive material may be capable of withstanding the high temperatures associated with engine combustion.
The electrical power developed by the thermoelectric device 10 may then be transferred to the point of use by wires (not shown)or any other type of electrical conductor known in the art. Referring to FIG. 4 , a first wire may connect the left-most semiconductor to the point of use and a second wire may connect the right-most semiconductor to the point of use, which may be an electrical battery or load. As a temperature gradient is viewed across device 10 , an electrical potential will be generated and seen across the first and second wires.
INDUSTRIAL APPLICABILITY
The present disclosure provides a system and method for recovering waste heat from an internal combustion engine for converting it to useful electrical energy. Internal combustion engines convert chemical energy into useful work by the combustion of a fuel and air mixture.
Referring to the particular embodiment of FIG. 1 , during combustion of a fuel and air mixture within combustion chamber 50 , heat is released causing the temperature within chamber 50 to rise. In some instances, the temperature may be as high as 750° C. The combustion gases are then used to drive piston 60 and connecting rod 62 down (as seen in FIG. 1 )—thus rotating a crankshaft (not shown) for the purpose of performing mechanical work.
Unfortunately, not all of the combusted fuel and air is converted into useful mechanical work. Some of the heat from the combustion process is thermally transferred to various engine components, such as head 1 , block 2 , and the exhaust system (not shown). Much of the thermal energy is wasted as it transfers to the environment.
The disclosed system transfers some of this thermal energy to hot side 11 of device 10 . In one particular embodiment, hot side 111 of device 10 is in direct contact with combustion chamber 50 , thus being exposed to the high temperatures resultant from the combustion process.
At the same time, engine coolant flows through channel 40 . This relatively cool coolant is in close proximity to cold side 12 ceramic of device 10 and is generally cooler than hot side 11 . In some embodiments, this coolant may have just exited the engine's jacket-water cooler or radiator. As a result, a temperature gradient is imposed across device 10 .
As long as this temperature gradient is maintained, electrical current will flow. This electrical current may then be used to supplement a vehicle's electrical loads, charge a battery, or perform any other function requiring electricity.
In one particular embodiment, the electrical energy generated is used support the electrical load of a hybrid machine. Hybrid vehicles and machines typically have a combustion engine and electric motor mechanically linked to a drive train for providing propulsion. In this particular embodiment, the electrical energy generated by device 10 would help power an electric motor, which when mechanically linked to a drive train, provides propulsion to the machine.
It will be apparent to those skilled in the art that various modifications and variations can be made with respect to the embodiments disclosed herein without departing from the scope of the disclosure. Other embodiments of the disclosed invention will be apparent to those skilled in the art from consideration of the specification and practice of the materials disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents. | In one particular embodiment, an internal combustion engine is provided. The engine comprises a block, a head, a piston, a combustion chamber defined by the block, the piston, and the head, and at least one thermoelectric device positioned between the combustion chamber and the head. In this particular embodiment, the thermoelectric device is in direct contact with the combustion chamber. In another particular embodiment, a cylinder head configured to sit atop a cylinder bank of an internal combustion engine is provided. The cylinder head comprises a cooling channel configured to receive cooling fluid, valve seats configured for receiving intake and exhaust valves, and thermoelectric devices positioned around the valve seats. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to toys and, more particularly, to apparatus for suspending a hard object within a soft bodied toy.
2. History of the Prior Art
Historically, toys which represent living creatures have been divided into two classes, hard bodied and soft bodied toys. Soft bodied toys may be easily designed to represent animals because the various plush materials available provide an easy way to represent animal coats. Plush toys provide a much more realistic appearance for animals than do hard bodied toys. Hard bodied toys, on the other hand, provide the support necessary for mechanical mechanisms which may be made to carry out various of the functions normally (or abnormally) performed by the creatures represented. Thus, a hard bodied toy may be easily provided with a mechanism for producing sound so that the toy may appear to speak or make animal noises. This ability to provide animal functions within a hard bodied toy also makes the toy seem more realistic.
In an attempt to make toys even more realistic, attempts have been made to combine these two types of toys. In general, hard bodied toys have been given outer skins of plush material to stimulate the skin of the animal. However, the toy remains a hard bodied toy, and does not have the soft pillowy feel of a soft bodied toy. Consequently, it is difficult to make these toys appeal to very small children who apparently realize that the toy is an unfamiliar mechanism rather than the cuddly animal it attempts to represent. When attempts have been made to suspend solid mechanisms within a soft bodied toy, the hard mechanism has a tendency to find its way to lie just below the surface of the soft material so that it is very apparent that a mechanism resides inside.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a soft bodied toy capable of holding within its body cavity a hard mechanism in a manner such that the presence of the mechanism is not obvious to a child.
It is another more specific object of the present invention to provide a toy having a soft body and a hard internal mechanism which may be easily manufactured.
These and other objects of the present invention are realized in a soft bodied toy comprising an outer layer of material, an inner layer of material, a relatively dense object positioned within the inner and outer layers, means fixing the outer and inner layers together to provide a space therebetween, stuffing material placed in the space to provide a soft cushion, the inner layer being of a form to provide a cavity for the hard inner mechanism, and means for holding the mechanism firmly within the inner layer.
These and other objects and features of the invention will be better understood by reference to the detailed description which follows taken together with the drawings in which like elements are referred to by like designations throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a an isometric view of a toy constructed in accordance with the invention.
FIG. 2 is a cross-sectional view of the interior of the toy taken along the line 2--2 of FIG. 1.
FIG. 3 is a bottom view of a portion of the toy illustrated in FIG. 1.
FIG. 4 is a front view of a portion of the toy illustrated in FIG. 1.
FIG. 5 illustrates details of the arrangement for accomplishing the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to FIG. 1, there is illustrated an isometric view of a toy 10 constructed in accordance with the invention. The toy 10 represents a dog although any of number of other animals might be represented. The toy 10 has a body 12, legs 13 attached to the body 12, a tail 14 also attached to the body 12, and a head 15 mounted upon the body 12. The head 15 positions two eyes 16 and a mouth 17. Other details of the exterior may be seen from the figure but are unimportant to the invention and for that reason are not mentioned in this description.
The entire exterior surface of the toy 10, except for trivial areas such as the surface of the eyes 16 and the mouth 17, is covered with a soft plush material of a color or colors such as to represent the color of a dog. Consequently, the toy 10 may be made to resemble a dog very closely. Within the exterior of the body 12 of the toy 10 is contained a thick layer of soft stuffing material of a type usually used for stuffing soft bodied toys. Supported within the stuffing material in accordance with this invention is a mechanism used to provide some realistic characteristic of a dog. In a preferred embodiment of the invention, the mechanism is adapted to cause the head 15 to move up and down and a tongue to move in and out of the mouth 17. As will be explained hereinafter, the manner in which the stuffing is accomplished makes the toy 10 feel as though it were a soft bodied toy even though a heavy mechanism is suspended inside.
FIG. 2 is a cross-sectional view of the interior of the toy 10 taken along the line 2--2 of FIG. 1. Shown in FIG. 2 are the head 15 and the body 12 of the toy 10. Positioned within the body 12 and the head 15 is illustrated a mechanism 20 adapted to produce the motion of the head 15 referred to above. The mechanism 20 is surrounded within the body 12 by soft stuffing material 22. The particular motion is one which is especially difficult to produce while maintaining the mechanism 20 in position within the body 12 so that a child will feel only the soft material surrounding the mechanism 20. The motion is difficult to produce because the mechanism must be very firmly positioned in order to be able to move the head 15 back and forth while the body remains still. It will be appreciated, however, that the arrangement of this invention by which the mechanism 20 is positioned within the body 12 is useful for positioning a hard mechanism within a soft body of a toy whether the mechanism be for producing this particular motion or some other motion. For example, the body 12 might be so positioned while a leg or a tail of the animal might be caused to move in accordance with the invention. In the simplest case, the mechanism 20 is positioned within the body without any movement of an appendage at all.
As may be seen in FIG. 2, the mechanism 20 includes a first portion 23 which is generally rectangular in cross section mounted within the body 12 and a second portion 25 mounted within the head 15. Also, it may be discerned from FIG. 2 that the head 15 and the body 12 are not separated as is the case with many soft bodied toys. In fact, the head 15 and the body 12 are formed with one continuous exterior 27 made of plush material in the preferred embodiment. The portion 23 of the mechanism has an extending portion 28 which projects upwardly and forms the interior of the neck of the toy 10. The extending portion 28 terminates in a generally-spherical end portion 29. The second portion 25 is shaped to fit the interior of the head 15 and has a portion 30 with a generally-spherical interior to fit over the end portion 28. Extending from the end portion 28 are short cylindrical pegs 31. The pegs 31 are adapted to fit within circular holes 32 in the portion 25 so that the portion 25 may pivot back and forth about the pegs in the direction shown by the arrow in FIG. 2.
The portion 23 of the mechanism 20 includes the mechanical or other devices for causing the movement of the portion 25 explained above. Since the particular mechanism forms no part of this invention, the details of that device are not included in this specification except that the head 15 pivots in the manner illustrated. However, it should be understood that the mechanism 20 may be quite dense compared to the other portions of the toy 10 because of the weight of the internal portions of the mechanism 20. In a particular toy 10, the mechanism 20 has an outer shell constructed of a hard moldable plastic material such as styrene which contains the inner mechanism (not shown).
In order to operate a mechanism such as the mechanism 20, it is usually necessary to utilize storage batteries or a mechanical wind-up arrangement. To this end, the mechanism 20 includes an opening 34 covered by a door 35 in the lower surface of the portion 23 as may be seen in FIG. 3. FIG. 3 is a bottom view of the mechanism 20. The door 35 maybe used to access the mechanism to replace batteries or to wind a mechanical mechanism. A switch 36 is illustrated adjacent the door 35 for actuating the mechanism 20; the preferred embodiment of the toy 10 uses an electrical mechanism 20, and the switch 36 turns on that mechanism. Surrounding the door 35 and the switch 36 is a downwardly extending ridge 38 which is flanged outwardly from the opening 34 at its extremity. Spaced from and paralleling the extreme flange 40 is a second flange 42 which projects from the ridge 38. The two flanges 40 and 42 form a channel surrounding the ridge 38 which is utilized to support the mechanism 20 within the toy 10. Another pair of flanges 44 and 45 surround the center of the extending portion 28 to form a second channel. A flange 47 is positioned at the extreme end of the portion 25 adjacent the mouth of the toy 10. The end of the portion 25 adjacent the flange 47 is shaped to provide a third channel for supporting the mechanism 20.
In order to provide the support for the mechanism 20 to hold it suspended within the soft body 12 and head 15, the exterior 27 and an inner layer of fabric 49 are sewn together to form an outer shell which surrounds the mechanism 20. The inner layer of fabric is sewn or formed into a shape such that it is adapted to fit snugly around the exterior of the mechanism 20. The shape of the inner layer 49 will, therefore, depend on the shape of the mechanism 20. It should be noted (see FIG. 5) that the shape of the inner layer 49 need only generally approximate the shape of the mechanism 20 because of the arrangement for securing the mechanism 20 to the inner layer to be described hereinafter. Consequently, if the inner layer is sewn, the seams may be made to be sewn on relatively straight lines and the amount of sewing minimized to provide rapid and economic assembly. Alternatively, the inner layer may be formed of a material such as a thin malleable plastic adapted to fit relatively tightly about the mechanism 20 so that the layer 49 itself acts as the means for securing the layer 49 to the mechanism 20.
The exterior 27 and the inner layer of fabric 49 may be joined at the mouth of the toy 10 and by webs or other pieces of material sewn or otherwise secured to maintain a generally fixed thickness for the space within the layers surrounding the mechanism. Thus, the layer 49 and the exterior 27 form a shell around the mechanism 20. Hollow tubes 48 are sewn into the inner layer of 49 adjacent the channels on the mechanism at the mouth, the neck, and at the door 35. Strings or plastic ties 50 are inserted in these tubes 48; and the tubes 48 in the inner layer are drawn tightly into the first, second, and third channels in the mechanism 20. The exterior 27 of the toy is left open at some point such as the rear of the toy 10 so that the shell or bag formed by the exterior 27 and the inner layer of fabric 49 may be stuffed after particular ones of the ties 50 have been secured to the mechanism 20. Thus, for example, the inner layer 49 may be fastened to the mouth of the toy 10 at the channel of the mechanism 20 adjacent the mouth of the toy 10; and a portion of the head stuffed. Then the layer 49 may be joined by a tie 50 at the channel at the neck and the remainder of the head 15 stuffed. The stuffing process may continue to fill most of the body 12. Then the tie to the channel surrounding the door 35 may be made; and the remainder of the toy 10 stuffed and closed.
FIG. 4 is a cross-sectional view taken along line 4--4 in FIG. 1 which illustrates that the shell made of the exterior 27 and the inner layer 49 may be extended beyond the door 35 and closed with a closure 55 device such as Velcro(R) or a zipper so that no portion of the mechanism 20 apart from that at the mouth of the toy 10 may be felt or viewed by a child from the exterior. FIG. 6 also shows that by stuffing the shell formed by the exterior 27 and the inner layer 49 tightly, there is no tendency for the mechanism to move within the soft bag. Consequently, the mechanism 2 will remain positioned within the central portion of the toy 10 so that the toy 10 will appear to be a soft toy throughout.
In a preferred embodiment of the invention, a second inner layer of fabric 51 of just larger than the size of the layer of fabric 49 is constructed and placed within the shell formed by the inner layer 49 and the exterior 27. The layer of fabric 51 becomes one side of the shell which is stuffed. The layer 51 is joined as by sewing to the layer of fabric 49 along the back of the toy 10. The layer 49 is joined to the mechanism 20 by ties as explained above. Then the mechanism surrounded by the layer 49 may be inserted into the pocket formed in the shell within the layer 51. The shell may be partially stuffed (e.g., at the head) before the insertion. As the stuffing continues to completion, the layer 49 may be sewn at a few points along the front and rear to secure the layer 49 firmly to the layer 51 so that the mechanism is firmly fixed within the soft body. By the process, the assembly of the toy 10 may be completed more expeditiously.
Although the layer 49 may be sewn to the layer 51 to assist in securing it in position, the major positioning in the preferred embodiment of the invention by which the hard mechanism 20 is supported within the soft body is the pair of tubes mating with the channels which fix the layer 49 in two planes to a portion of the mechanism which is to be suspended. Thus the channels into which the tubes of the layer 49 are firmly fixed provide a pair of fixed planes at which the outer soft portion of the body 12 is joined to the body portion of the hard mechanism 20. In a like manner, the soft outer head portion is joined to the head portion of the hard mechanism 20 at a pair of planes formed by the channels at the mouth and neck. With these two planes of the soft outer body affixed to the hard portion inside, when the soft body is stuffed the hard inner portion is isolated from the exterior of the toy. Thus, whenever a portion of a soft toy is to move relative to some other portion, this may be accomplished by fixing each of the portions to its exterior at a pair of planes. In a case in which a relatively small portion such as a tail is to move with respect to a relatively larger portion such as the body, one of the two planes may be replaced by a single point to which the exterior may be firmly fixed (e.g., the end of the tail).
Although the present invention has been described in terms of a preferred embodiment, it will be appreciated that various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention. The invention should therefore be measured in terms of the claims which follow. | A soft bodied toy including an outer layer of material, an inner layer of material, a relatively dense object positioned within the inner and outer layers, apparatus fixing the outer and inner layers together to provide a space therebetween, stuffing material placed in the space to provide a soft cushion, the inner layer being of a form to provide a cavity for the hard inner mechanism, and apparatus for holding the mechanism firmly within the inner layer. | 0 |
BACKGROUND OF THE INVENTION
The invention relates to a device for forming store units from a thread supplied from a yarn packet, in which the store units are successively laid onto a carrying surface and there temporarily are enclosed between a back and a front limiting means, as seen in the supply direction, said limiting means being adapted to assume alternately with a phase shift an operative and an inoperative position, such that each time when the front limiting means assumes the inoperative position, the front store unit is released for being drawn from the carrying surface, and the next store unit assumes the position of the released store unit.
Such a device is e.g. known from U.S. Pat. No. 4,132,370. In this known device which is designed for intermittently feeding the weft transporting device of a shuttleless weaving machine, the carrying surface is part of a winding drum onto which the thread store units are laid through the intermediary of a rotating winding arm in the shape of thread windings. The limiting means are therein constituted by pins carrying out a translation movement in a plane containing the axis of the winding drum, such that said pins successively move outwardly from the space within the drum and at the release end of the drum are again retracted. As soon as the front limiting pin is retracted into the space within the drum the store winding which was up till that moment confined behind said pin is drawn by the weft transporting device of the weaving machine, while the store winding which is formed behind the next limiting pin is moved towards the drawing off end of the drum in order to be released during the next weft phase of the weaving machine for being drawn off.
A disadvantage in such a device is that the last part of a thread store winding, which has been released for being drawn off, is suddenly drawn taut at the end of the drawing off movement around the next limiting pin (which constitutes the front limiting pin for the next store unit) which causes a pull on the thread. Thereby tension peaks may be generated which may lead to thread failure.
The invention aims at removing this disadvantage.
SUMMARY OF THE INVENTION
According to the invention this aim is achieved in that over the carrying surface a brake means has been provided which in the last phase of the movement of the store unit which has been released for being drawn off, is adapted to assume an operative position relative to the carrying surface, in order to brake the drawing off movement during that phase.
Generally the last portion of a thread store unit will extend more or less transversally relative to the drawing off direction. By the measure according to the invention the deflection of the last thread portion at the end of the drawing off movement to the stretched condition in the supply direction takes place more gradually so that pulls on the stretching thread and thereby tension peaks are avoided.
In a preferably applied embodiment in which the carrying surface, as in the above mentioned known device, is part of a stationary winding drum cooperating with a rotary winding arm and the store units are laid onto the drum in the shape of windings, the brake means according to the invention is constituted by a brake shoe cooperating with the drum surface.
In a practical embodiment the brake shoe surface facing the drum surface is provided with bristle hairs.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic plan view of the device according to the invention arranged between a yarn packet and a weft transporting device for a pneumatic weaving machine;
FIG. 1A shows the winding drum of the device according to the invention during a phase in which a yarn unit is drawn from the drum;
FIG. 1B is a plan view of the winding drum of the device according to the invention, in which it is indicated how the last portion of the drawing off movement occurs as influenced by the braking means, and
FIG. 2 shows an end view of the device according to the invention in which the brake means is in its operative position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device bearing the reference number 1 in the drawing has a sleeve shaped supporting part 2 with the intermediary of which the device may be secured to the frame of a yarn processing machine, particularly a shuttleless weaving machine. In this sleeve shaped supporting part 2 a shaft 3 is rotatably journalled and carries at its end projecting left in the drawing beyond the supporting part 2 a driving disc 4 which is drivable in a predetermined ratio to the main drive shaft of the yarn processing machine. The shaft 3 has an axial bore 5 for guiding the yarn 7 supplied from the yarn packet 6. Reference number 8 indicates a rotary part of the device which is secured to the shaft 3 and contains a yarn guide channel 5 which connects the central yarn guide bore 5 to an aperture 10 at the periphery of the rotary part 8. Reference number 11 indicates a stationary winding drum which remains stationary when the shaft 3 rotates.
The casing of the drum 11 has an axial slot 12 through which limiting pins 13 may project from the space within the drum outwardly and simultaneously may move in axial direction, to the right as shown in the drawing. Said pins form part of a mechanism which is not further shown in the drawing and is known per se, which is mounted inside the drum 11 and e.g. has the embodiment hereinbefore described as shown in U.S. Pat. No. 4,238,080.
Reference number 14 indicates a thread guide eye arranged in the axis of the drum 11 and serving for guiding the yarn, which is intermittently drawn off the drum 11, to the weft transporting means indicated at 15 which is fed with transport air e.g. at 16.
So far the device is of a structure which is known per se, at least described in earlier patent applications.
According to the invention the drum 11 cooperates with a brake means 17 constituted by a brake shoe arranged at the side of the slot 12 remote from the direction X of rotation of the rotary part 8 and secured to a lever 18, which is pivotable around a fixed point 19 between an inoperative and an operative position (see FIG. 2). The lever 18 carrying the brake shoe 17 is curved over the drum and is connected at its end 20 remote from the pivot point 19 to an actuating rod 21, the movement of which, indicated by the two-headed arrow, is derived in a manner not further shown from the main shaft of the yarn processing machine or weaving machine respectively. In the embodiment shown the operative surface of the brake shoe 17 facing the drum is provided with bristle hairs.
In FIG. 1 the device according to the invention is shown at a moment in which both limiting pins 13 are in their operative position and therefore project outwardly. The left pin 13 has just moved outwardly from the space within the drum through the slot 12, while the right pin 13 is about to move inwardly through the slot 12. In the position shown a predetermined number of yarn windings is present between both pins. This number of yarn windings constitutes a store unit. When applied to a weaving machine the number of yarn windings of this store unit is selected in correspondence with the weaving width. In practice this will be e.g. five windings but in the drawings for clarity's sake only three windings have been shown. The left pin therein constitutes a separation between said store unit and the windings which are laid onto the drum by the rotary part 8 left of this pin and which are to constitute the next store unit.
FIG. 1A shows the device at a moment during which a store unit is drawn from the drum 11 under the influence of the pulling force imparted by the weft transporting device 15 to the store unit. In that moment the right limiting pin 13 according to FIG. 1 has a position retracted into the space within the drum 11, while the left limiting pin 13 according to FIG. 1 is still in its operative position and has been moved to the right. The store unit forming left of the pin 13 in FIG. 1A is almost complete, that is a next limiting pin is about to move outwardly at the left end of the slot 12. In the moment as shown in FIG. 1A only a portion of the last winding of the relative store winding is present on the drum 11. It is clear that this last winding portion would be drawn taut shortly afterwards with a pull around the limiting pin 13 and that thereby a tension peak in the yarn would occur. According to the invention such a tension peak is countered in that, at the moment of FIG. 1A in view, the brake shoe 17 is moved towards the drum surface. The result thereof is that the displacement in axial direction of the last winding portion to be drawn off takes place more gradually and that the stretching yarn of the relative store winding nestles more gradually around the limiting pin 13 as shown in FIG. 1B. It is clear that controlling the brake shoe must be done such that the brake shoe only becomes operative during the last part of the drawing off movement. In application to a weaving machine this means that the brake shoe is only operative during the last part of the weft phase of a weaving cycle, that is always in a rather accurately defined period. | A device for forming store units from a thread supplied from a yarn packet. The store units are formed on a winding drum between limiting pins which may assume an operative and an inoperative position. A brake means, e.g. brake shoe, is applied to the last part of a thread winding being released from the drum in order to avoid pulls and thereby tension peaks on the thread which otherwise might cause thread failure. | 3 |
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/502,507, titled the same, filed Sep. 12, 2003 and incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to antennas and, more particularly, to overmolded antenna systems.
BACKGROUND OF THE INVENTION
[0003] Cellular telephone, PDA, and other wireless devices send and receive data using radio frequency (“RF”) transmissions. The RF transmissions are sent and received through an antenna. One currently useful antennal is a flex film antenna, which are commonly used in the art.
[0004] Conventionally, flex film antennas are constructed using one of two ways. The first methodology involves a snap together antenna. The second methodology involves an overmolded single core. Neither of these designs is satisfactory. Using these designs, the following and other problems still exist with flex film antennas:
A single piece core component is required in existing simplified overmolded flex film antenna designs to facilitate the plastic molding process. This design excludes the internal volume of core component as a possible location for the flex film radiator element. Existing overmolded flex film antenna radiators antenna systems have a limited usable radiator surface typically limited to the radial surface area of the single piece core component. The electrical connection of the flex film to the metallic threaded connector (radio interface) on existing designs use solder or axial compression. Soldering is expensive and introduces variation in the amount of solder deposited, thus variation in antenna performance from antenna to antenna. Axial compression interface (used on “snap together” designs) relies on a component of the antenna to apply compressive load to the flex film. This component is typically the outer sheath that is susceptible to the external environment and possible damage from drop. Additionally the sheath is typically a polymer which overtime will lose its material properties as it is under constant tensile load in these designs. As the sheath weakens, the compressive load diminishes thus increasing the likelihood of intermittent flex film to metallic connector electrical connection. Flex film tears easily when a load is applied to the material. A unique assembly interface is needed to accomplish a consistent interface and a manufacturable design.
[0009] Thus, it would be desirous to develop a flex film antenna that addressed these and other problems.
SUMMARY OF THE INVENTION
[0010] The present invention provides a flexible film antenna. The flexible film antenna includes a radiating element comprising a conductive trace on a flexible film. The flexible film is mounted on a core. The core comprises at least two parts that are releasably coupled together in snap or sliding relation. A feed post extends out a base of the core to connect to a power feed. Finally, a protective housing can be molded over the antenna.
[0011] The foregoing and other features, utilities and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention, and together with the description, serve to explain the principles thereof. Like items in the drawings are referred to using the same numerical reference.
[0013] FIG. 1 is a partially exploded, perspective view of an antenna comprising an embodiment of the present invention without the housing;
[0014] FIG. 2 is a partially exploded, perspective view of the core of FIG. 1 comprising an embodiment of the present invention without the housing;
[0015] FIG. 3 is a partially exploded, perspective view of the base of the antenna of FIG. 1 ;
[0016] FIG. 4 is a cutaway of the antenna of FIG. 1 ; and
[0017] FIG. 5 is a cross-sectional view of the antenna of FIG. 4 .
DETAILED DESCRIPTION
[0018] The present invention will be further explained with reference to the FIGS. 1-4 . In particular, FIGS. 1-4 show an overmolded antenna with a multi piece core assembly and flex film radiating element consistent with an embodiment of the invention. The multi piece core increases the usable surface area for the radiating flex film element. This is accomplished by “threading” the flex film in between the core pieces, thus using the internal volume region of the core system. ( FIG. 1 ). The actual placement of the flex film radiation element within the internal volume is dependent, in part, on design choice and, in part, on functional requirements of the antenna.
[0019] FIG. 1 shows portions of an antenna 100 . Antenna 100 comprises a core 102 or support structure on which a flexible film 104 is wound. A power feed element 106 connects to a base 108 of antenna 100 .
[0020] Flexible film 104 comprises a non-conductive material 110 , typically a flexible plastic, rubber, or the like, with one or more conductive traces 112 , such as copper or the like, on the non-conductive material 110 . The size, shape, dielectric constant, etc. of the non-conductive material and the size, shape, and placement of the conductive trace(s) 112 are largely a matter of design choice and radiating characteristics of antenna 100 . Flexible film 104 comprises a power connection 114 . Power connection 114 comprises a portion of non-conductive material 106 and conductive trace 108 operatively coupled to power feed element 106 , as will be explained further below. Power connection 114 is shown with a single power feed, but multiple power feeds could be used instead of the single feed line as shown. Further, conductive traces 112 shown could be a single trace or multiple traces as shown.
[0021] Referring now to FIG. 2 , core 102 is shown in more detail. Core 102 comprises at least two releasably coupled parts, upper part 202 and lower part 204 . Upper and lower are relative terms and used only in connection with FIG. 2 for reference. Upper and lower should not be considered limiting.
[0022] Upper part 202 has an upper support section 206 and a top portion 208 . Upper support section 206 comprises a half cylinder with a convexly shaped outer surface 210 and a substantially flat lower part interface 212 . Top portion 208 comprises a full cylinder with a convexly shaped outer surface 214 . Top portion 208 has at least one upper recess 216 extending below a plane defined by lower part interface 212 . Upper support section 206 has at least one upper protrusion 218 extending from an upper part base 220 , which is opposite top portion 208 . The at least one upper protrusion 218 resides just above lower part interface 212 . At least one alignment recess 222 extends along a length lower part interface 212 . Upper part 202 may have one or more relief troughs 226 as necessary. Top portion 208 has a guide ridge 224 extending about outer surface 214 . Upper part 202 is described with several components, however, one of ordinary skill in the art on reading the disclosure will now understand that upper part could be a single molded piece of plastic or multiple pieces of molded plastic coupled together.
[0023] Lower part 204 has a lower support section 230 and a bottom portion 232 . Lower support section 230 comprises a half cylinder with a convexly shaped outer surface 234 and a substantially flat upper part interface 236 . Bottom portion 232 comprises a fully cylinder with a convexly shaped outer surface 238 . Bottom portion 232 comprises at least one lower recess 240 above upper part interface 236 that is shaped to slidably couple to the at least one upper protrusion 218 . Lower support section 230 comprises at least one lower protrusion 242 below upper part interface 236 that is shaped to slidably couple the at least one upper recess 216 . An alignment tab 244 resides on upper part interface 236 and is shaped to slidably couple to alignment recess 222 . Alignment tab 244 also engages an alignment cutout 116 (See FIG. 1 ) in the flexible film to assist in aligning the flexible film 104 on core 102 .
[0024] Bottom portion 232 has a guide ridge 224 , a power feed recess 246 , a power connection slot 248 , and at least one power feed support post 250 . Power feed support post 250 is shown as two power feed support posts 250 or tabs extending into power feed recess 246 . It has been found using two separated power feed support posts 250 inhibits tearing of flexible film 104 , which can cause a power failure or disconnect. Power connection slot 248 could form a through hole or bore in the at least one power feed support post 250 if desired.
[0025] As shown, core 102 has a generally cylindrical shape that converges from bottom portion 232 to top portion 208 . The shape of core 102 could be as shown, a straight cylinder, a cubic shape, a conical shape, or other polygonal shapes as a matter of design choice. However, to the extent core 102 has edges, the edges should be beveled or chamfered to reduce damage to flexible film 104 .
[0026] Referring back to FIG. 1 , flexible film 104 and core 102 may be assembled by inserting power connection 114 through power connection slot 248 such that power connection 114 extends from bottom portion 232 . Further cutout 116 would be aligned with alignment tab 244 such that flexible film 104 resides one upper part interface 236 and extend beyond outer surface 234 . Upper part 202 would be arranged such that alignment tab 244 aligns with alignment recess 222 . Upper part 202 would be pushed down on lower part 204 until lower part interface 212 substantially abutted flexible film 104 . Upper part 202 would than be slidably moved along lower part 204 until at least one upper protrusion 218 and at least one lower recess 240 , and at least one lower protrusion 242 and at least one upper recess 216 slidably engaged forming a puzzle lock arrangement.
[0027] Flexible film 104 would than be wrapped or threaded around outer surfaces 210 , 214 , 234 , and 238 . Flexible film 104 further comprises an adhesive 118 such that when flexible film 104 is completely wrapped or threaded around core 102 , adhesive 118 would couple flexible film 104 to itself or one of outer surfaces 210 , 214 , 234 , and 238 to inhibit unraveling of flexible film 104 .
[0028] Referring to FIGS. 3 and 5 , power feed element 106 is described in more detail. Power feed element 106 comprises a plug portion 300 that fits into power feed recess 246 . Plug portion 300 comprises a base 302 having an annular ledge 304 , which could be contiguous as shown or at least one tab, on which bottom portion 232 resides. Extending into power feed recess 246 is an outer plug surface 306 . Outer plug surface 306 defines an inner plug recess 308 . Inner plug recess 308 is shaped to cooperatively engage at least one power feed support post 250 . Power feed support post 250 may not extend fully into inner plug recess 308 , which may leave a small gap G.
[0029] Generally, core 102 is formed from non-conductive plastic. Power feed element 106 is formed from conductive metal. Referring specifically to FIG. 3 , power connection 114 is bent over the at least one power feed support post 250 . Power feed element 106 is plugged into power feed recess 246 such that outer plug surface 306 plugs into power feed recess 246 and the at least one power feed support post 250 snuggly fits (i.e., plugs) into inner plug recess 308 such that the conductive trace 112 on power connection 114 engages metal plug portion 300 forming a radial power feed connection. Forming core 102 of plastic and power feed element 106 from metal reduces failures do to plastic fatigue.
[0030] Once power feed element 106 is plugged into power feed recess 246 , a housing 400 may be applied around core 102 forming antenna 100 . Optionally, housing 400 can be formed by injection molding housing 400 around the device by placing power feed element 106 in a recess in a mold. The device is stabilized by connecting a portion of the top portion 208 to prongs, which may result in an annular void 402 at the peak 404 of housing 400 .
[0031] Guide ridges 224 are useful in aligning flexible film 104 about core 102 , but also serve to inhibit flexible film 104 from peeling or unraveling from core 102 when housing 400 is molded about core 102 . Further, a portion 120 of flexible film 104 may be cut to remove edges that the molding may cause to peel, unravel, or tear.
[0032] While the invention has been particularly shown and described with reference to an embodiment thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made without departing from the spirit and scope of the invention. | The present invention provides a flexible film antenna. The flexible film antenna includes a radiating element comprising a conductive trace on a flexible film. Flexible film is mounted on a core. The core comprises at least two parts that are releasably coupled together in snap or sliding relation. A feed post extends out a base of the core to connect to a power feed. Finally, a protective housing can be molded over the antenna. | 7 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 11/279,497, filed Apr. 12, 2006, now U.S. Pat. No. 7,740,923 claiming priority to European Patent Application No. 05008398.9, filed Apr. 18, 2005, which are incorporated by reference herein in their entirety.
FIELD
The invention relates to a package, a food product packaged with the package, as well as a method and a machine for producing a packaging material or for packaging a food product and a packaging material produced thereby.
Particularly in the field of packages for food products, it is desirable to provide the consumer with a package, which is both easy to open and re-closable. However, with re-closable packages it is an issue that the package might have been opened and re-closed before the consumer purchases and/or consumes the food product contained in the package. In other words, it is important for the consumer to know whether a third person (or the consumer himself, beforehand) has tampered with or opened the package. This information is important as it will influence the consumer's decision to purchase the product and/or the consumer's decision to consume the product despite the fact that the package has been opened and re-closed and the food product contained therein might not be in the original state and might, particularly, not be in a fresh state.
BACKGROUND
As far as tamper evidence is concerned, it is known to provide additional mechanical features, such as a sticker or a label, which need to be broken in order to open the package. This type of tamper evidence complicates the manufacturing and the packaging process and, moreover, deteriorates the easy to open properties of the package.
EP 0 341 699 B1 discloses tamper indicating containers and seals, in which a colorant is at least partially removed, when the seal is first opened, so that the first opening is indicated, and the consumer can realise that the package has been tampered with. A similar tamper evidence seal and tape is disclosed in WO 96/04177.
EP 1 288 139 of the Applicant discloses a package for packing food products which is easy to open due to the presence of two easily gripable flaps having a different width.
SUMMARY
It is an object underlying the invention to provide a package which is improved with regard to its tamper evidence features, as well as a food product packaged therewith. Furthermore, the invention provides a method and a machine for producing a packaging material or for packaging a food product which can produce a package, which comprises improved tamper evidence. Finally, a packaging material produced thereby is also subject matter of the invention.
The package according to the invention is described in claim 1 . Preferred embodiments thereof are the subject of the further claims.
The package according to the invention comprises, firstly, a substrate. The substrate can be any type of film or foil from any type of suitable material, such as polyethylene or polypropylene or paper coated with a plastic material. In particular, the substrate can advantageously be suitable for the production of so-called flow packs, i.e. packages which are produced by wrapping a foil or film material around a succession of products, sealing the foil or film to itself between products and producing a so-called fin seal parallel to the machine direction, i.e. the direction of the succession of products. The packed products are separated from one another by cutting transversely to the machine direction in the area of the seals, which are formed between the products.
In the inventive package, a first and a second surface portion of the substrate are sealed to each other. The first and second surface portion can, for example, be parallel to each other and can, moreover, be parallel to the machine direction and thus constitute the above-described fin seal. These surface portions can be sealed to each other by a cold or heat seal as desired. The seal can be patterned, i.e. the sealant or adhesive producing the seal can be applied in a pattern, such as plural dots, stripes or any other suitable pattern and the first and second surface portions can, moreover, be subjected to embossing in order to improve the strength of the seal.
A third surface portion adjacent the first surface portion is at least partially covered by a coating. It can be mentioned that the third surface portion can act as a type of flap or tab adjacent the first surface portion that can be gripped when it is desired to open the package, in order to achieve an easy opening of the seal constituted by the first and second surface portions. It can, moreover, already be mentioned that the coating of the third surface portion has a particular colour in order to provide a tamper evidence feature. In particular, a binding force, between the coating and the substrate, has a first value. This first value will be in a specific relationship with the values of further binding forces, as detailed below, in order to provide the tamper evidence feature.
A fourth surface portion is present adjacent the second surface portion and is only partially covered with an adhesive. In a manner corresponding to the third surface portion, the fourth surface portion can be considered as a flap or tab adjacent the second surface portion. Moreover, the fourth surface portion is, furthermore, at least partially in contact with the third surface portion. Thus, at least one of the third and fourth surface portions can easily be gripped when it is desired to open the package and a separating force can be applied to these surface portions in order to separate the sealed first and second surface portions from each other and allow access to the product contained in the package. It is to be noted that the fourth surface portion is only partially covered with an adhesive, so that the fourth surface portion is only partially bonded to the third surface portion. Thus, there are parts of the third and fourth surface portions which are not bonded to each other and which can, therefore, easily be gripped in order to open the package. Thus, the inventive package is easy to open which is beneficial for the consumer.
As far as the adhesive is concerned, with which the fourth surface portion is only partially covered, a bonding force between the adhesive and the substrate, as well as the coating, respectively, has a second and a third value, respectively. Both the second and third values are greater than the first value. Since the first value is related to the bonding force between the coating and the substrate, a separation of the third and fourth surface portions from each other will cause the coating to adhere to the adhesive and will, thus, be removed from the third surface portion. This is because, as mentioned above, the bonding force between the adhesive and the substrate as well as the coating is higher than the bonding force between the coating and the substrate. Thus, the adhesive will, firstly, adhere to the fourth surface portion. Secondly, due to the bonding force between the adhesive and the coating, which are at least partially in contact with each other, the coating will adhere to the adhesive and will be removed from the substrate of the third surface portion, because of the relatively low bonding force, having the first value at this interface.
Thus, when the package is first opened, the coating is at least partially removed from the third surface portion. For example, the removed part of the coating can represent the word “opened” so that after the first opening, this message is conveyed to the consumer. In a similar manner, also that part of the coating, which stays on the third surface portion, can represent this word or any graphic or written information in order to indicate that the package has already been opened or has been tampered with. It will also be appreciated that a higher opening force will be required for the first opening than for any subsequent openings. This is because during the first opening, the coating will at least partially be removed from the third surface portion. Subsequently, the removed part of the coating adheres to the adhesive on the fourth surface portion and will, also after re-closing, stay on the adhesive of the fourth surface portion. Thus, during subsequent openings, only that part of the adhesive, which adheres to the third surface portion, and not that part of the adhesive, which is covered with the removed coating, needs to be separated from the third surface portion. Due to the reduced surface area, which adheres to the third surface portion, the opening force is reduced and the consumer can additionally “feel” that the package has already been subjected to a first opening. As detailed above, the consumer can also visually recognise this fact, because at least a part of the coating of the third surface portion has been removed.
The visual effect is obtained as a colour of the coating is different than a colour of the third surface portion and/or the fourth surface portion and/or the adhesive. When the colour of the coating is different from the colour of the third surface portion, the coating can be partially removed from the third surface portion during the first opening, so that the consumer will realize that only a part of the coating (having a different colour than the third surface portion) has stayed with the third surface portion. This remaining part can convey the “opened” message by exhibiting this or similar word(s), or by representing specific graphic information. Moreover, the colour of the coating can be different from the colour of the fourth surface portion, because the adhesive on the fourth surface portion will at least be partially covered with the coating after the first opening. Therefore, the difference in colour between the coating which adheres, by means of the adhesive, to the fourth surface portion, and the fourth surface portion itself can be used for indicating the first opening and/or tampering. Finally, the surface area of the fourth surface portion, which is covered with adhesive, can be greater than the area of the third surface portion, which covered with coating. Thus, the coating, which has been removed from the third surface portion, can, after the first opening, be surrounded by areas of adhesive on the fourth surface portion. Thus, when a colour difference between adhesive and the coating is present, the first opening or tampering information can be conveyed to the customer in this manner.
Thus, the coating and the adhesive are, in the final package, at least partially in contact with each other, so that separating the fourth surface portion from the third surface portion will at least partially remove the coating from the third surface portion. As mentioned, the third and fourth surface portions can represent flaps or tabs which are in contact with each other, so that the coating provided on the third surface portion and the adhesive provided on the fourth surface portion are in contact. Due to the relationship of the various bonding forces described above, the process of separating the fourth surface portion from the third surface portion will at least partially remove the coating from the third surface portion. As detailed above, due to the colour differences, this removal of the coating can provide an indication that the package has been opened or tampered with.
As will be appreciated from the above, the measures described herein do not require any separate mechanical features, such as additional stickers or labels. Rather, the coating and the adhesive can easily be applied to the substrate when the substrate, which can, for example, be present as a web, is traveling through the packaging machine, and a succession of products are packaged, for example, in a flow-wrap or flow-pack type package. Moreover, the package according to the invention can be produced in two steps, which can particularly be performed at different locations, with the production of a packaging material being a first step. In connection therewith, a substrate, which can be present as a web, can be coated and/or printed with the above-described adhesives, sealant and coatings such as ink or primer. The packaging material can then be wound to rolls or reels, which can be delivered to a different company, which intends to package their goods with the described packaging material. The company using the packaging material then only has to unwind the packaging material and the goods can be packaged without any additional devices or steps being required during packaging. This advantageously keeps the packaging machinery uncomplicated and the necessary investments for the company using the packaging material low.
In particular, the adhesive on the fourth surface portion can be the same as, and can be continuous with, the adhesive which is used for sealing the first and second surface portions to each other and, possibly, further surface portions. Also the coating of the third surface portion can be readily applied to the substrate in the process of packaging food products. It should, moreover, be mentioned that the tamper evidence feature is realized in the third and fourth surface portions, which are adjacent the first and second surface portions, respectively, which are sealed to each other. Thus, the seal, as such, is not affected by the tamper evidence feature. In particular, the seal can be provided in a way to ensure reliable sealing and, preferably, re-closability, whereas the tamper evidence feature, which is present in the third and fourth surface portions, can, substantially independent from the seal, be provided in a reliable and efficient way.
In particular, the first and second surface portions, respectively, which form the seal, are preferably not formed in a way to integrate or surround the third and fourth surface portions, respectively, or be surrounded by the latter. Rather, the third surface portion is adjacent the first surface portion and there is, if any, a single borderline between them, which is preferably straight. Moreover, one or more further surface portions can even be present between the first and the third surface portion. The above also is applicable to the relationship between the second and fourth surface portions. In particular, the third and fourth surface portions are preferably formed on free edges of the package, so that they can constitute two gripable flaps. Finally, all of the described surface portions are preferably formed substantially rectangular. The invention is applicable to the package described in EP 1 288 139 A1 of the Applicant, the disclosure of which is, with regard to the package as such, including the seal and flaps thereof, incorporated herein by reference. It should be mentioned that the invention is also applicable to so-called vertical form fill seal bags and pouches. In such types of packages, for example, pieced goods such as candy or small confectionary products can be packaged. In connection with vertical form fill seal bags and pouches, it should be noted that the surface portion comprising the coating can be parallel as well as substantially perpendicular to the machine direction, i.e. the direction, in which the packaging material is conveyed through the machine. This also applies to any horizontal packaging machines. Moreover, one or more of the seal described above can be formed as heat seals instead of cold seals.
Preferred embodiments of the inventive package are described in the further claims.
As mentioned above, the substrate can be made of any suitable material. Currently, the use of a film for the substrate is preferred, as a film material will advantageously allow the invention to be used with a flow-wrap type of package.
Moreover, the invention is not dependent on the first and second surface portions being present on the same side of the substrate. However, it is advantageous if the first and second surface portions are indeed on the same side of the substrate, as an efficient packaging method can be used, as a fin seal can be provided between the first and the second surface portions being on the same side of the substrate.
As regards the seal between the first and second surface portions, this can be formed by an adhesive, such as a cold seal, a heat seal, a pressure sensitive glue or any other suitable type of seal. In particular, pressure sensitive glue can be covered with a heat seal lacquer in order to seal the package. In this case, the seal can be broken along the pressure sensitive glue. All of these embodiments represent a reliable and efficient type of seal.
Generally, the invention, due to the tamper evidence feature, is exhibiting specific advantages in re-closable packages, so that it is currently preferred that the seal between the first and the second surface portions is re-closable.
The first and second surface portions can have a shape and/or structure to provide a completely closed package. For example, the package can be a type of envelope with three permanently closed sides, and the remaining side being closed by the seal between the first and the second surface portions. Because of the flow pack type of package, which is currently preferred for the package described herein, it is, however, preferred that there is a fifth and/or sixth surface portion, which is respectively sealed to itself. As mentioned above, the first and second surface portions can constitute a fin seal. In this type of package, the fifth and/or sixth surface portion can constitute one or two end seals, which are substantially perpendicular to the fin seal. In particular, a relatively wide seal, which is oriented substantially perpendicular to the machine direction, can be provided between two products, and a cut can be made in the area of the end seal in a direction perpendicular to the machine direction, in order to separate two packages, each containing a product, from each other. Thus, the fifth and/or sixth surface portion are preferably substantially perpendicular to the first and/or second surface portions.
As it provides advantages, when the third and/or fourth surface portions constitute flaps or tabs which can be used for opening the seal between the first and second surface portions, it is advantageous when the third and/or fourth surface portions or immediately adjacent the first or the second surface portions, respectively.
The third and the fourth surface portions are preferably of a different size which implies that one of these surface portions extends beyond the other one. In this manner, it can be easily realized that gripping tabs or flaps are present. Moreover, due to the different extension, one or both of the third and fourth surface portions can be gripped in order to separate them from each other and open the package. In connection with the differing size of the third and fourth surface portions, reference can additionally be made to the above referenced application of the Applicant.
Generally, the above-described effects of the coating, based on the colour thereof, can be achieved with any type of coating. However, since the coating essentially has to provide the indicating effect, it is currently preferred that the coating is a primer or an ink, which adheres to the substrate of the package.
As regards the amount of coating, tests have shown that the coating can advantageously be applied with 0.5 to 2 g/m 2 with 1.4 to 1.6 g/m 2 being preferred.
It has, furthermore, been realized in experiments, that the reliability of the coating being removed from the third surface portion can be improved when the coating is, in addition to the adhesive provided on the fourth surface portion, at least partially covered with an adhesive. In particular, when the adhesive on the fourth surface portion and the adhesive covering the coating are at least partially in contact with each other, the adhesive of the fourth surface portion will at least partially adhere to the adhesive covering the coating and will improve the reliability, with which the coating, which is present underneath the adhesive on the third surface portion, is removed. Moreover, it can be advantageous to have continuous areas, which are covered with adhesive, so that it is advantageous to cover at least a part of the coating on the third surface portion with adhesive. It is to be emphasized that the described feature, namely the coating, in addition to the fourth surface portion, being at least partially covered with adhesive, represents a feature which can be provided on the package described herein, in which the fourth surface portion does not necessarily have to be only partially covered with the adhesive. In other words, in this case, the fourth surface portion can be completely covered with adhesive. The feature, that the coating is at least partially covered with adhesive, can be combined with one or more of the features mentioned above and below as desired.
In view of the even higher force for reliably removing a part of the coating from the third surface portion, it is, as mentioned, advantageous if the adhesive on the fourth surface portion and the adhesive covering the coating are at least partially in contact with each other.
In this context, the effects can be further improved when the bonding force between the adhesive on the fourth surface portion and the adhesive covering the coating has a fourth value, which is higher than the first value. Thus, the coating on the third surface portion will reliably be removed during first opening.
It is currently preferred that the adhesive is a cold seal or a heat seal. In this embodiment the adhesive can be formed continuous with a seal between the first and second, as well as on the fifth and/or sixth, surface portions, which provide advantages with regard to the covering of the required areas of the substrate with the seal.
When the adhesive is pressure sensitive glue or adhesive, the packaging of the food product can be facilitated, because the bonding of the adhesive can be realized by pressure, without heat or similar effects being necessary. Furthermore, the adhesive can contribute to the re-closability of the package and the package can be improved in this regard.
Experiments have shown that it is advantageous if the adhesive is applied with 3 to 5 g/m 2 , preferably 3.5 to 4.0 g/m 2 .
The seal between the first and the second surface portion and/or the seal of the fifth surface portion and/or the seal of the sixth surface portion and/or the adhesive can comprise a pattern. This can reduce the amount of adhesive or sealant, which is required, as the necessary effects can possibly be obtained by a reduced amount of sealant or adhesive, which is, for example, applied in a dot and/or a stripe pattern.
As can be taken from above, the relationship between the various values of bonding forces is most relevant for obtaining the desired effects. As regards the absolute values, 0.5 to 1.5 N/15 mm have proven advantageous for the first value of the bonding force. In this context, the given force corresponds to that force, which is necessary to peel a strip of material having a width of 15 mm and being coated with the respective material. This force can, in particular, be measured in accordance with the draft for DIN 55529.
The second value of the bonding force can be 4.5 to 7 N/15 mm, as tests have shown.
As regards the third value of the bonding force, 2 to 4 N/15 mm, preferably greater than 3 N/15 mm have shown to be advantageous.
Finally, 2.5 to 4 N/15 mm are preferred for the fourth value of the bonding force.
Generally, the inventive package can be applied to any kind of product. However, for food products, in particular confectionary products, the provision of both re-closability and tamper evidence, which the invention provides, is particularly relevant, so that a food product, particularly a confectionary product, which is packaged with a package, in one of the above-described embodiments, is part of the invention. In this context, the food product can be a tablet, block or bar shaped product. However, the food product can also be one or more pieced goods.
The invention is, furthermore, constituted by a method for producing a packaging material or for packaging a food product as described herein. Corresponding to the package, which is to be obtained, at least a first and a second surface portion of a substrate are covered with a sealant. A third surface portion adjacent the first surface portion is covered with a coating and a bonding force between the coating and the substrate has a first value. Moreover, only a part of a fourth surface portion adjacent the second surface portion is covered with an adhesive and a bonding force between the adhesive and the substrate as well as the coating, respectively, has a second and a third value, respectively, both the second and third value being higher than the first value. Moreover, the colour of the coating is different than the colour of third and/or fourth surface portions and/or the adhesive. As described before, these steps can either be part of a method for producing a packaging material or for packaging a food product. When a packaging material is to be produced, the substrate is covered with sealant and coating in the above-described manner. However, there can be applications, where the packaging material is covered with either the sealant or the coating, as well as applications, in which only some of the surface portions are covered with sealant and/or coating. Such embodiments are part of the invention. In practice, further surface portions can be covered at a different location, for example, when the packaging material is to be used for packaging one or more products. In the method for producing a packaging material, the method can comprise the step of winding the packaging material so as to produce a roll or reel material which can then be delivered to the company that intends to use the packaging material for packaging their goods.
In the method for packaging the food product, the first and second surface portions are sealed and the coating and the adhesive are at least partially brought in contact with each other. This method provides an efficient and uncomplicated method for producing a package as described above, which is particularly improved with regard to tamper evidence.
Preferred embodiments of the inventive method substantially correspond to the preferred embodiments of the package and are described in the further claims. In connection with the inventive method, it should be mentioned separately that the substrate can be conveyed in a machine direction and the first and/or second surface portion can extend substantially in the machine direction, so that they constitute a fin seal. However, the first and/or second surface portions as well as the third and fourth surface portions can also extend substantially perpendicular to the machine direction, in other words in a cross machine direction and can, thus, be formed as end seals of the package. Moreover, the seal between the first and/or a second surface portion as well as the seal of the fifth and/or sixth surface portion can be embossed with a pattern in the method described herein. The embossed pattern can, for example, be one or more lines or stripes, which extend substantially parallel to the length of the respective surface portion. In particular, in a preferred embodiment, embossed lines or stripes extend substantially parallel to the length of both the first and second and the fifth and sixth surface portion. In this context, the length or extension of the respective surface portion is the longer dimension of the surface portion, which can have a substantially rectangular shape.
The invention, moreover, provides a machine for producing a packaging material or for packaging a food product which is adapted to carry out the above-described method and/or produce the inventive package or the packaging material described below. Thus, the packaging machine comprises a device for covering at least a first and a second surface portion of a substrate with a sealant. Moreover, the machine comprises a device for covering a third surface portion adjacent the first surface portion with a coating, a coating force between the coating and the substrate having a first value. The machine also comprises a device for covering only part of a fourth surface portion adjacent the second surface portion with an adhesive. With these devices, a packaging material, as described below, can be produced. In this context, not all of the above-described devices do necessarily have to be present. Rather, only one or some of the mentioned devices can be provided in order to produce an intermediate type of packaging material. In particular, the remaining devices can be provided within a packaging machine which is then adapted to “complete” the packaging material and which can, additionally, be adapted to package one or more products.
When a packaging machine is to be provided, a device for sealing the first and second surface portion and a device for bringing the coating and the adhesive at least partially in contact with each other are provided.
Preferred embodiments of the machine correspond to preferred embodiments of the inventive method and are described in the further claims. The machine can comprise a device for conveying the substrate in a machine direction, the first and/or second surface portions extending substantially in the machine direction.
The machine can be kept uncomplicated when the device for covering the first and second surface portions and the device for covering the fourth and/or the fifth and/or the sixth surface portions, are constituted by a single device. Thus, continuous surface portions covered with an adhesive can be formed by a single device.
The machine can comprise a printer for covering the described surface portions with the coating in the form of ink or a primer.
The invention finally provides a packaging material, in which the first and second, third and fourth surface portions are covered as described above for the final package. Such a packaging material can also have only some of the described surface portions covered in the described manner, and either the coating or the sealant can be applied to the packaging material. The packaging material can be produced and then supplied to the company that intends to use it for packaging goods. In particular, the packaging material can be provided as a reel or roll material.
BRIEF DESCRIPTION OF THE DRAWINGS
Hereinafter, preferred embodiments of the invention will be described with reference to the drawings, in which:
FIG. 1 shows a plan view of the substrate of the inventive package in a first embodiment before closing the package;
FIG. 2 shows the substrate of FIG. 1 after the first opening;
FIG. 3 shows a plan view of the substrate of the inventive package in a second embodiment before closing the package;
FIG. 4 shows a plan view of the substrate of the inventive package in a third embodiment before closing the package;
FIG. 5 shows the substrate of FIG. 4 after the first opening;
FIG. 6 shows a perspective view of a bag which can be produced using the substrate of FIG. 4 ;
FIG. 7 shows a plan view of the substrate of the inventive package in a fourth embodiment before closing the package;
FIG. 8 shows the substrate of FIG. 7 after the first opening; and
FIG. 9 shows a perspective view of a bag, which can be produced using the substrate of FIG. 7 .
DETAILED DESCRIPTION
As FIG. 1 shows, the substrate 12 of the inventive package is, in the preferred embodiment, a substantially rectangular piece of film material. This piece can be part of a web, which is conveyed through a packaging machine in the machine direction A. In the final package, the white area 32 , which is also substantially rectangular and located in the centre of the substrate 12 , will be used to enclose a product 34 . Moreover, in the final package, the package will be sealed by seals, which are formed between a first 14 and a second 16 surface portion as well as by sealing a fifth 28 and a sixth 30 surface portion to itself. On the basis of the above terminology, the seal of the fifth 28 and sixth 30 surface portions 30 constitute end seals, and the seal between the first 14 and the second 16 surface portions can constitute a fin seal. In the embodiment shown, the first, second, fifth and sixth surface portions, which constitute the various seals, form a kind of rectangular frame. In particular, they are, in this preferred embodiment, formed on the same side of the substrate 12 .
As can also be taken from the drawings, a third 18 and a fourth 22 surface portion are present adjacent the first 14 and second 16 surface portions, respectively.
As described in the above-referenced earlier application of the Applicant, these surface portions can constitute tabs or flaps, which can be gripped by the consumer in order to separate the first 14 and second 16 surface portion from each other in order to open the seal and get access to the contents of the package. As indicated by the colouring of the third 18 surface portion this surface portion 18 is covered with a coating 20 . In the embodiment shown, the coating 20 covers the entire third surface portion 18 but this is not necessary. Furthermore, FIG. 1 shows an embodiment in which the colour of the coating 20 is remarkably darker than the colour of the substrate 12 , which is visible in the uncovered and uncoated central area 32 . In the embodiment shown, the coating 20 is, moreover, partially covered by an adhesive 26 . In particular, three strips of adhesive, which extend substantially perpendicular in the machine direction A, are applied on the coating 20 . It is to be understood, however, that the strips or stripes can have a different shape and/or size, and the areas, where the adhesive and/or the coating is applied, can have any suitable appearance.
In the embodiment shown, the fourth surface portion 22 comprises similar strips of adhesive 24 . In particular, the strips of coating 20 and/or adhesive 26 ( FIG. 1 ) can be present every 10 to 50 mm. In particular, the fourth surface portion 22 is only partially covered with adhesive 24 , so that areas remain free of adhesive, which can be gripped in order to separate the third 18 and fourth 22 surface portions from each other and, as a consequence, separate the first 14 and second 16 surface portions from one another in order to open the package.
FIG. 1 shows the substrate before a food product is packaged. In particular, the substrate shown in FIG. 1 can be part of a packaging material in the form of a web, on which the pattern of sealant, adhesive and coating is repeated several times. In the case shown, the web extends in the machine direction A, with the fifth surface portion 28 of a first substrate being substantially adjacent the sixth surface portion 30 of another substrate. When a food product is to be packaged, the product indicated at 34 is placed on the central area 32 of the substrate, and the substrate is wrapped around the food product 34 . During this process, the fifth 28 and sixth 30 surface portions are sealed to themselves, and the first 14 and second 16 surface portions are sealed to each other.
Moreover, the third 18 and fourth 22 surface portions come in contact with each other. In particular, the adhesive 24 , partially covering the fourth surface portion 22 , contacts the adhesive 26 provided on the coating 20 . It should be mentioned that this adhesive 26 is not absolutely necessary. Rather, the adhesive 24 on the fourth surface portion 22 can be in direct contact with parts of the coating 20 . When such a package is first opened, the third 18 and fourth 22 surface portions are separated from each other, and the adhesive 24 , provided on the first surface portion 22 , removes a part of the coating 20 .
FIG. 2 shows the substrate corresponding to that of FIG. 1 after the first opening. As can be seen, the adhesive 24 on the fourth surface portion 22 is covered with coating, which has been removed from the third surface portion 18 . Since the colour of the coating 20 differs from that of the fourth surface portion 22 , the consumer can see that the package has been opened. In particular, the adhesive 24 on the fourth surface portion 22 could be applied in a manner to show the word “opened”, so that the “opened” message is displayed after first opening.
In the embodiment shown, the coating 20 also has a different colour than the third surface portion 18 . Therefore, in view of the fact that the entire third surface portion 18 is, in the embodiment shown, covered with a coating 20 , strips 36 on the third surface portion 18 , which are free of coating, are visible. In the embodiment shown, the substrate has a uniform, light, preferably white colour throughout all surface portions, so that the above effects are obtained. However, it is also sufficient if the coating has a colour, which is different from that of the third 18 or the fourth 22 surface portion. Moreover, when the area of the fourth surface portion 22 , which is covered with adhesive 24 , is greater than the area of the third surface portion 18 , which is covered with coating 20 , it is sufficient if the colour of the coating 18 differs from that of the adhesive 24 . Since all of the coating will be removed from the third surface portion, the difference of colour between the coating, which covers part of the adhesive on the fourth surface portion 22 , and the surrounding adhesive will be visible.
When the package is to be re-closed, the first 14 and second 16 surface portions can again be sealed to each other, and the fifth 28 and sixth 30 surface portion can be sealed to themselves. This provided re-closability and requires a certain opening force also for subsequent openings. However, as can be taken from the drawing, the adhesive 24 on the fourth surface portion 22 is covered with coating, which will not adhere to the third surface portion 18 . Thus, there is no bonding force active in this area and the consumer can also feel that there is a lower opening force than for the first opening. This provides tamper evidence in addition to the above-described visual effects. It is also evident that the substrate does not necessarily have to be brought into the state shown in FIG. 2 , when the package is to be opened. Rather, if only a part of the product, such as a part of a chocolate bar or tablet is to be consumed, it will be sufficient if the seal between the first 14 and the second 16 surface portions is opened partially, and the adjacent end seal, i.e. the seal of the fifth 28 or the sixth 30 surface portion is opened. When the remainder of the product is to be kept in the re-closed package, only the opened seals have to be re-closed. In particular, when the package is opened only partially, only one or two of the stripes of coating can be removed. In the case of a different pattern of coating 20 and/or adhesive 24 and 26 on the fourth surface portion 22 and the coating 20 , respectively, only part of the coating is removed during partial opening, which still indicates that the package has at least been partially opened.
As can be taken from FIG. 3 , the second embodiment of the inventive package differs from the first embodiment only with regard to that part of the third surface portion 18 , which is covered with a coating 20 . In particular, in the embodiment shown in FIG. 3 , only three strips are covered with coating. In the embodiment shown, the location and size of the strips correspond to the location and size of the strips of adhesive 26 covering the coating 20 in the embodiment of FIG. 1 . However, it is to be understood that the pattern, with which the coating 20 is applied to the third surface portion 18 , could be completely different. Moreover, in the embodiment shown in FIG. 3 , the strips of coating 20 are, at least to a large extent, covered by adhesive 26 , similar to the strips of adhesive 26 in the embodiment of FIG. 1 . As noted above, these strips of adhesive 26 are not necessary. Rather, also the strips of adhesive 24 , which are provided on the fourth surface portion 22 , will come into contact with the strips of coating 20 , when the package is closed, in order to package a product indicated at 34 .
Due to the relationships of the various bonding forces, the adhesive 24 of the fourth surface portion 22 will remove the coating 20 from the third surface portion 18 in order to provide tamper evidence. In particular, as the fourth surface portion 22 adheres to the third surface portion 18 , due to the adhesive 24 , the coating 20 is not visible to the consumer before the first opening. After the first opening, or when the package has been tampered with, the coating 20 covers the adhesive 24 on the fourth surface portion 22 and is, therefore, visible. In particular, the coating could form the word “opened” in order to inform the consumer that there has been a first opening.
In the embodiment shown in FIG. 3 , substantially all of the coating provided on the third surface portion 18 can be removed. Therefore, the colour of the coating 20 is in this case different from that of the fourth surface portion 22 and/or the adhesive 24 provided on the fourth surface portion 22 , in order to make the coating visible, which has been removed from the third surface portion 18 and adheres to the adhesive 24 on the fourth surface portion 22 . Thus, the appearance of the fourth surface portion 22 after the first opening will substantially correspond to that of the fourth surface portion 22 of the first embodiment, shown in FIG. 2 , whereas the third surface portion 18 will be substantially free of adhesive and coating 20 . Both of the embodiments described above can be produced easily and efficiently and products, in particular food products, can be packaged with the above-described tamper evidence features being applied in line, i.e. during packaging the product. As an alternative, the described substrate can be part of a packaging material comprising a plurality of portions constituting plural substrates, with which a plurality of food products can be packaged with the final package exhibiting the described tamper evidence features.
FIG. 4 shows a plan view of the substrate 12 in a second embodiment. As regards the first 14 , second 16 , third 18 and fourth 22 surface portions this embodiment generally corresponds to that of FIG. 1 . This also applies to the stripes of adhesive 24 , which are provided on the fourth surface portion 22 , the coating 20 of the third surface portion and the stripes of adhesive 26 , which are provided on the coating 20 and, partially, in the embodiment shown, on the first surface portion 14 . The embodiment of FIG. 4 differs from that of FIG. 1 because a fifth 28 and a sixth 30 surface portions are provided as heat seals. Moreover, a heat seal area indicated at 38 can be present adjacent the first 14 and second 16 surface portions, respectively. It should be noted that there can be a distance or spacing between one or both heat seal areas 38 and the first 14 and second 16 surface portions, respectively. Moreover, the heat seal areas 38 can also be present between the first and third and between the second and fourth surface portions. With the described heat seals, hermetic sealing of the final package can be realised. In other words, the package can be formed airtight and vapour proof, so that the final package is also suitable for products such as cheese or coffee, which require hermetic packages. It can be mentioned that the heat seal area 38 can also be provided as a lacquer on top of the adhesive or sealant of the first 14 and second 16 surface portions. When both heat seals and re-closable adhesives are provided, as in the embodiment of FIG. 4 , a package can be provided, which is hermetically sealed in the original state, and which is re-closable after the first opening. It should also be mentioned that the heat seal features of the embodiment of FIG. 4 can also be provided to the first and second embodiments described above, as well as the fourth embodiment, described below. In the embodiment of FIG. 4 , the machine direction is indicated with arrow A and a web, extending in the direction A and constituting a plurality of substrates as shown in FIG. 4 , can be used in a vertical packaging machine for producing packages in the form of bags or pouches. Such a bag will be described with reference to FIG. 6 below.
FIG. 5 shows the substrate of FIG. 4 in the fully opened state. In other words, the bag or pouch produced from the substrate of FIG. 4 is fully opened, and all seals are broken in order to show the plan view corresponding to FIG. 4 . As can be taken from FIG. 5 , in a manner corresponding to that described above with reference to FIGS. 1 and 2 , a part of the coating 20 of the third surface portion 18 has been removed so that coating free, stripes 36 are visible which indicate that the package has been opened and/or been tampered with. This function fully corresponds to that described above with reference to FIGS. 1 and 2 and does not have to be repeated here. In particular, the modification of FIG. 3 is also applicable to the embodiment of FIGS. 4 and 5 .
FIG. 6 shows a perspective view of a bag 10 produced from the substrate of FIG. 4 . In particular, the bag 10 is shown in an opened state and it can be seen that the orientation has been changed by 90 degrees relative to the orientation shown in FIGS. 4 and 5 . In particular, during manufacture of the packaging material and/or the package, the heat seals of the fifth 28 and sixth 30 surface portions can be called end seals. However, in use, as can be taken from FIG. 6 , these will constitute the sides of the bag 10 . The top is constituted by the first 14 , second 16 , third 18 and fourth 22 surface portion, comprising the tamper evidence features as described above. In particular, stripes of adhesive 24 covered with coating 20 , which has been removed from the third surface portion 18 are visible on the fourth surface portion 22 . As regards the bottom 40 of the bag 10 , this is formed in a way to create a stand-up bag by appropriately folding the substrate 12 during production of the bag. In particular, a fold line, which is substantially parallel to the machine direction A is created in approximately the centre of the substrate in order to produce the bottom shown at 40 in FIG. 6 . In particular, the heat seals of the fifth 28 and sixth 30 surface portions have the shape of an inverted Y, which is produced by folding a centre portion of the substrate 12 inwards which is an upwards direction in the orientation of the bag 10 shown in FIG. 6 . As regards further details of such a bag or pouch, as well as the manufacture thereof, reference can be made to the WO 03/080441 A1, the disclosure of which is incorporated herein by reference.
FIG. 7 shows a further embodiment of a substrate 12 , from which a package in the form of a bag can be produced. In this case, those surface portions providing the tamper evidence features are provided at an “end” of the substrate considering the machine direction A. At the sides and a second end of the substrate 12 , heat seal areas 42 are provided, which are sealed to themselves. In a sense, the substrate 12 , shown in FIG. 7 , is folded about a line running through the centre of the substrate 12 parallel to the machine direction A. Moreover, as with the embodiment of FIGS. 4 and 5 , a heat seal area 38 can be present adjacent the first 14 and second 16 surface portion. It should be noted that the first 14 and second 16 surface portions are in this embodiment continuous with each other. This also applies to the third 18 and fourth 22 surface portions. The heat seal area 36 can also be spaced from the area covered with adhesive constituting the first 14 and second 16 surface portions. Furthermore, the heat seal area 38 can also be present between the first and second surface portions, on the one hand, and the third and fourth surface portions, on the other hand. In this embodiment, the area constituting the first 14 and second 16 surface portions is essentially sealable to itself, with the left half of this area constituting the first surface portion 14 , and the right half constituting the second surface portion 16 .
In the embodiment of FIG. 7 , the entire third 18 and fourth 22 surface portions are covered with a coating 20 . In the embodiment shown, two stripes 24 of adhesive are formed on the fourth surface portion 22 , and two corresponding stripes 26 are formed on the coating 20 of the third surface portion 18 . When the package is formed, the stripes 24 are at least partially brought into contact with the stripes 26 . Thus, when the package is opened, the coating is removed from the third surface portion 18 , as shown in FIG. 8 . However, unless the bonding forces differ from each other, the coating could also be removed from the fourth surface portion 22 . As a further alternative, in the embodiment shown comprising two stripes 24 and 26 , one coating free stripe 36 can be present on the third surface portion 18 , and one coating free stripe 36 can be present on the fourth surface portion 22 .
FIG. 9 shows a package in the form of a bag 10 , which can be formed from the substrate shown in FIG. 7 . The heat seal areas 42 , extending parallel to the machine direction A, constitute a side of the package and the heat seal area 42 , extending substantially perpendicular to the machine direction A, i.e. the above-mentioned second end seal constitutes the bottom 40 of the bag. The tamper evidence features are provided at the top of the package. In this context, FIG. 9 shows a somewhat different embodiment with four stripes of adhesive 24 , which are covered with removed coating after first opening. Between the second and third stripe a gripping area 44 and a hole 46 for hanging the bag to a suitable carrier can be provided. As regards the embodiment of FIGS. 7 to 9 , it can be mentioned that the fourth surface portion 22 does not have to be covered with coating entirely. Rather, only the area underneath the stripes 24 of adhesive and/or the surroundings thereof, can be covered with coating, in order to provide the tamper evidence feature, when the stripes of adhesive 26 , which are provided on the third surface portion, remove the stripes of adhesive 24 including the coating underneath from the fourth surface portion 22 . Finally, it should be mentioned that any features, which are mentioned with regard to a single or only some embodiments above, are applicable to all other embodiments as well. | A package material with a tamper evident feature and methods of manufacture thereof, are disclosed herein. The package comprises a colored primer or lacquer coating applied along a portion of a seal and further comprising a peelable sealant. When opened the peelable sealant is separated from the portion of the seal containing colored primer or lacquer and removes a section of the coating, thus providing a visual indication that the package has been opened. | 8 |
CROSS REFERENCE TO OTHER APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application 60/601,401, filed on Aug. 13, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates generally to fence structures and methods of construction. More particularly, it relates to a chain link fence having privacy slats inserted into the fence with an image applied to at least one side of the slats for decoration, information, advertising or other purposes.
BACKGROUND OF THE INVENTION
[0003] The following patent publications relate to chain link fence constructions having slats, tiles or panels inserted into the fence for privacy, wind protection, decoration, information, advertising or other purposes. These and all other patents and patent applications referred to herein are hereby incorporated by reference.
[0004] U.S. Pat. No. 6,708,955 granted to Cummings for Lattice insert
[0005] Abstract: An insert consisting of a plastic square that is fastened to a plastic garden-lattice that affects the lattice's functional and ornamental characteristics. This device is dispersed throughout the lattice according to personal preference to achieve varying degrees of both function and ornamentation, with regards to protection from the elements, colors, composition, letters, numbers, embossing, etc.
[0006] U.S. Pat. No. 6,669,175 granted to Snow, et al. for Tile type fencing insert
[0007] Abstract: A rectangular sheet of flexible and resilient material such as plastic with notches at the midpoint of its sides. The size of the sheet and notches allow the insert to be placed into and located by a cell of a chain link fence. Notches fit around the wire crossovers of the chain link fence and locate the insert at the mid-plane of the fence. The corners of the insert extend into adjoining cells. Adjoining inserts overlap to provide complete visual privacy. The tile-like nature of the inserts allows great flexibility in arrangements and colors to provide visual privacy, decoration, words, logos, or signage.
[0008] U.S. RE36,085 granted to McLaughlan, et al. for Chain link fencing with decorative slats that provide complete privacy
[0009] Abstract: Chain link fencing having a plurality of elongate picket members comprising elongate slats that lie in diagonal valleys of the chain link fencing. Elongate, U-shaped channels lie along the respective sides of each elongate slat. The channels fit over and cover a row or ridge of knuckles formed along the side of each of the respective valleys of the chain link fencing. The pickets cover essentially the entire side of the chain link fence and leave no spaces or openings between pickets. The system thus provides complete privacy. Engagement members are associated with the channels to secure the channel members and thus the pickets to respective rows or ridges of knuckles on the chain link fencing.
[0010] U.S. Pat. No. 5,395,092 granted to McLaughlan, et al. for Chain link fencing with decorative slats that provide complete privacy
[0011] Abstract: Chain link fencing having a plurality of elongate picket members comprising elongate slats that lie in diagonal valleys of the chain link fencing. Elongate, U-shaped channels lie along the respective sides of each elongate slat. The channels fit over and cover a row or ridge of knuckles formed along the side of each of the respective valleys of the chain link fencing. The pickets cover essentially the entire side of the chain link fence and leave no spaces or openings between pickets. The system thus provides complete privacy. Engagement members are associated with the channels to secure the channel members and thus the pickets to respective rows or ridges of knuckles on the chain link fencing.
[0012] U.S. Pat. No. 5,275,381 granted to Cluff, et al. for Wire fencing with decorative slats that provide essentially complete privacy
[0013] Abstract: Wire fencing having a plurality of elongate picket members that lie adjacent to a side face of the chain link fencing so as to be substantially superposed over the fencing. Engagement members extend from the back faces of the picket members to project into the fencing and engage respective mounting members positioned within the fencing or on the opposite side face of the fencing. The interengagement of the engagement members and the mounting members holds the picket members firmly in place on the side of the fencing.
[0014] U.S. Pat. No. 5,234,199 granted to Cluff for Chain link fencing with decorative slats
[0015] Abstract: In a chain link fence having a plurality of elongate slats woven through the links of the chain link fabric, an improved system for retaining and locking the slats in the chain link fabric comprises (1) an elongate rail woven between consecutive links of the chain link fence such that the rail lies adjacent to mutually respective, aligned, first ends of the elongate slats, and (2) engagement members formed integrally with the mutually respective first ends of the elongate slats, with the engagement members including interlocking means which make interlocking engagement with the elongate rail when the respective first end of the elongate slat is abutted against the elongate rail.
[0016] U.S. Pat. No. 5,165,664 granted to Cluff for Chain link fencing with decorative slats
[0017] Abstract: In a chain link fence having a plurality of elongate slats woven through the links of the chain link fabric, an improved system for retaining and locking the slats in the chain link fabric comprises (1) an elongate rail woven between consecutive links of the chain link fence such that the rail lies adjacent to mutually respective, aligned, first ends of the elongate slats, and (2) engagement members formed integrally with the mutually respective first ends of the elongate slats, with the engagement members comprising a pair of separate, distinct, spaced apart barbs positioned adjacent to the respective side edges of the slat. The barbs make interlocking engagement with the elongate rail when the respective first end of the elongate slat is abutted against the elongate rail.
[0018] U.S. Pat. No. 4,725,044 granted to Cluff for Chain link fencing containing decorative slats and locking clips
[0019] Abstract: In a chain link fence having a plurality of elongate slats woven through the links of the chain link fabric, an improved system for locking and retaining the slats in the chain link fabric comprises an elongate clip member which is received in locking interengagement in a receptacle or opening in the respective slat. The clip member can be of the type which simply extends from the sides of the slat to form an obstruction with the links in the fence such that the slats cannot be removed from the fence. Alternatively, the clip members can be adapted to extend from the slat to a bottom rail so as to lock the slats to the bottom rail such that the slats cannot be removed from the fence.
[0020] U.S. Pat. No. 4,723,761 granted to Cluff for Chain link fencing containing decorative slats
[0021] Abstract: A means for retaining slats woven flatwise through the links of a chain link fence is provided with a receptacle formed in each of the slats and a generally U-shaped clip member having legs engaging respective receptacles in adjacent slats.
[0022] U.S. Pat. No. 4,651,975 granted to Howell for Insert member for chain link fences
[0023] Abstract: A device designed to be secured to a chain link fence improves the appearance of the fence and partially closes the openings in the fence so as to provide privacy and wind protection. Decorative blocks, such as of wood or plastic, are installed onto the obliquely angled wires of the fence via a wire-receiving groove formed in one surface of each block. Each block extends partially over each of two adjacent fence openings on either side of the wire. Flexible connectors, such as of light wire, are strung generally in lines to connect the series of blocks and secure their position and orientation. Installation of a large number of the blocks provides the appearance of a closed fence, improves the appearance of the fence and provides some wind protection.
[0024] GB 2329913 filed by Haynes et al. for Screened chain link fencing
[0025] Abstract: A chain link fence, made from wire mesh which is screened by means of the insertion of lightweight slats which are secured parallel to each other by means of a u-shaped channel, and, or the use of a securing wire, which can be passed through a securing stud in or to prevent their movement or unwanted removal of the slats from the fence. If required the slats can be printed, or a sign or image applied to the slats, so as to provide a slatted hoarding for the presentation of information such as an advertisement.
SUMMARY OF THE INVENTION
[0026] One disadvantage of many of the prior art privacy fences is that they do not provide an adequate level of privacy. It is easy for passers by to focus through the gaps between the colored privacy slats to see what is behind the fence. On the other hand, the few examples that are configured to provide complete privacy by overlapping the slats to eliminate the gaps require more elaborate construction and are consequently more expensive to make and install. What would be desirable therefore is a privacy fence that provides enhanced privacy without having to resort to complex and expensive constructions.
[0027] To solve this problem, the present invention takes advantage of the eye's natural tendency to focus on an image that is presented to it. When the eye is focused on an image in the foreground, the background will be out of focus and will largely be ignored by the observer. By placing a decorative image on the surface of a privacy fence, the eyes will be drawn to the image and will focus on it. Even though the fence is not completely opaque, objects and activities behind the fence will be ignored by the casual observer. This provides an enhanced level of privacy without having to resort to complex and expensive fence constructions. The decorative privacy fence of the present invention can also be configured to provide additional advantages, such as wind protection, decoration, information, advertising, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows a front view of a decorative privacy fence constructed in accordance with the present invention having a chain link fence with privacy slats inserted into the chain link fence with an image applied to at least one side of the slats.
[0029] FIG. 2 shows a rear view of a decorative privacy fence constructed in accordance with the present invention.
[0030] FIG. 3 is an enlarged view showing construction details of the decorative privacy fence.
[0031] FIG. 4 shows construction details of optional features of the decorative privacy fence.
[0032] FIGS. 5A and 5B show a top view and an end view of a fixture used for manually laminating an image onto the privacy slats of the decorative privacy fence.
[0033] FIG. 6 shows an end view of a privacy slat after lamination.
[0034] FIG. 7 shows an interim step in the manufacture of privacy slats from a flat panel of material.
[0035] FIG. 8 shows an end view of finished privacy slats made from a flat panel of material.
DETAILED DESCRIPTION OF THE INVENTION
[0036] FIG. 1 shows a front view of a decorative privacy fence 100 constructed in accordance with the present invention. The privacy fence 100 is configured as a chain link fence made from interwoven strands of wire 102 that form an interwoven wire fabric 112 . The interwoven wire fabric 112 is typically supported between upright posts 116 , which are optionally connected by horizontal rails 118 at the top and bottom of the fence 100 . The interwoven pattern of the wire 102 leaves a multiplicity of open vertically oriented channels 104 into which a multiplicity of privacy slats 106 can be inserted.
[0037] The privacy slats 106 typically have an elongated rectangular configuration when viewed from the front. In one preferred configuration shown in FIGS. 3 and 6 , when viewed from the ends, the privacy slats 106 are typically configured with an elongated rectangular cross section with rounded lateral edges. In one particularly preferred embodiment, the privacy slats 106 are formed as a thin-walled, hollow profile polymer extrusion with internal walls or webbing between the opposing faces. This configuration reduces the weight of the privacy slats 106 and saves materials costs. Alternatively, the privacy slats 106 may be configured with flattened tubular or channel-shaped cross section or other convenient shape. The privacy slats 106 are preferably constructed of a low cost, durable, weatherproof material, for example a polymer such as polyvinyl chloride or a polymer composite. The privacy slats 106 may be formed by extrusion, rolling, stamping, molding or other convenient manufacturing process. The privacy slats 106 may be colored in the manufacturing process or left a natural color.
[0038] The privacy slats 106 are preferably configured with at least one generally flat surface 108 onto which an image 110 can be applied. The image 110 can be applied to the privacy slats 106 using any known process that results in a durable, weatherproof image. The flat surface 108 of the privacy slats 106 must be compatible with the image application process. In one preferred method, the image 110 is formed on a durable, weatherproof polymer film, such as polyvinyl chloride or mylar. The polymer film with the image 110 on it is cut into strips approximately the width of the privacy slats 106 and applied to the flat surface 108 using an adhesive, such as a contact adhesive previously applied to the back surface of the polymer film. Advantageously, it has been found that the adhesion of the laminated image to the slats actually increases with time and weathering. Optionally, an image can be applied to both surfaces of the privacy slats 106 .
[0039] The privacy slats 106 with the image 110 applied to them are inserted into the open vertically oriented channels 104 in the chain link fence 112 as shown in FIG. 1 . FIG. 2 shows a rear view of the completed privacy fence 100 . Optionally, the back surface of the privacy slats 106 can have an image applied to it as well or it may have a uniform color or a pattern on it.
[0040] For standard chain link fences with a repeat pattern of approximately 3½ inches, the privacy slats 106 will preferably have a width of approximately 2¼ inches and a thickness of approximately ¼ inch to fit into the open vertically oriented channels 104 in the woven wire fabric 112 . Privacy slats 106 with a width of approximately 1 inch and a thickness of approximately ¼ inch can be used for smaller mesh sizes of chain link fence. The length of the privacy slats 106 will preferably correspond to the height of the woven wire fabric 112 of the privacy fence 100 . The privacy slats 106 can be manufactured in any other dimensions to accommodate other mesh sizes of chain link fences.
[0041] FIG. 3 is an enlarged view showing construction details of the decorative privacy fence 100 . Optionally, the privacy slats 106 can be secured in place by bending the free ends 114 of the wires 102 over at the top and/or bottom of the chain link fence. Alternatively, locking devices, such as those described in the prior art, may be used to secure the privacy slats 106 in place.
[0042] FIG. 4 shows construction details of optional features of the decorative privacy fence. In order to avoid distortion of the image printed on the privacy fence 100 , is important that the privacy slats 106 be properly aligned with one another along the fence, particularly as compared to prior art privacy fences that use solid colored privacy slats. To achieve this, the lower ends of the wires 102 can be bent into lower support loops 120 that support the privacy slats 106 at the same correct height, thus providing a datum for aligning the portions of the image printed on each of privacy slats 106 .
[0043] FIGS. 5A and 5B show a top view and an end view of a fixture 200 used for manually laminating an image onto the privacy slats 106 of the decorative privacy fence 100 . The fixture 200 is preferably configured to be used on a horizontal table. The fixture 200 includes a multiplicity of channels 202 separated by raised fences 204 . The raised fences 204 will preferably have a height approximately the same as the thickness of the privacy slats 106 . Alignment pins 206 or other alignment features are located approximately on the centerline of each of the raised fences 204 . A multiplicity of undecorated privacy slats 106 are placed in the channels 202 of the fixture 200 with the upper and lower ends of the slats aligned and the flat surface 108 facing upward. Next an image formed on a polymer film 122 is adhesively attached to the flat surface 108 of the privacy slats 106 . A steel rule or the like (not shown) is aligned with the spaces between the privacy slats 106 using the alignment pins 206 on the centerline of the raised fences 204 . The polymer film 122 with the image on it is slit between the privacy slats 106 using a razor knife or other sharp cutting blade. Preferably, the raised fences 204 will be made of wood or metal to resist damage by the cutting blade. The cut polymer film 122 is wrapped around and adhered the rounded lateral edges of the privacy slats 106 , preferably covering the privacy slats 106 up to approximately the midpoint of the rounded lateral edges, as shown by the arrow marked W in FIG. 6 , which shows an end view of a privacy slat 106 after lamination. This configuration of the privacy slats 106 has an additional advantage in that the image on the privacy slats 106 appears more continuous than if it had only been applied to the flat surface 108 , including when the fence is viewed from angles other than perpendicular to the front surface of the fence. Preferably, the privacy slats 106 are marked with numbers, letters or other indicia prior to removal from the fixture 200 to indicate the order of the slats for later insertion into the open vertically oriented channels 104 of a chain link fence 112 . For example, the indicia may be applied using removal labels. A portion or all this manual process may be automated for more rapid and efficient manufacturing of the decorative privacy fence 100 . In addition, the insertion of the privacy slats 106 into the open vertically oriented channels 104 of a chain link fence 112 may be automated. For example, the privacy slats 106 may be inserted into the vertically oriented channels 104 of a chain link fence 112 as the woven wire fabric is being formed.
[0044] FIG. 7 shows an interim step in the manufacture of privacy slats from a flat panel of material 130 . In this method an image is first applied to a rigid flat panel of material 130 , then the flat panel and the image are cut into strips to form a multiplicity of privacy slats 106 , as shown in FIG. 8 .
[0045] In general, the image may be applied to the flat panel shown in FIG. 7 , or alternatively to slats, using any acceptable method. For example, the image may be applied to the flat panel 130 by printing the image onto a polymer film, for example 3M Controltac IJ180C film, and laminating the printed polymer film onto the flat panel 130 . The image may be printed on the polymer film using a wide format printer, such as those available from Mutoh, Encad, ColorSpan or Hewlett-Packard. Alternatively, the image may be printed directly onto the flat panel 130 using a wide format flatbed printer, such as those available from Mutoh, Encad or Mimaki. If the flat panel 130 is treated prior to printing, it can be printed on using solvent base inks. If the flat panel 130 is untreated, it can be printed on using UV cured inks. In other embodiments, the image is created using autosterioscopic technologies, such as those using paralax barriers, lenticular sheets, or other methods to create holographic or 3D images, moving images, changing images, and other effects that may be readily created using such technology. In some embodiments both sides of the slats, and thus the fence incorporating the slats, may include an image formed thereon.
[0046] In one preferred embodiment, the flat panel 130 is configured as a hollow cell profile extrusion formed of a polymer, including, but not limited to, PVC, polypropylene or polyethylene. The end view of the flat panel 130 in FIG. 7 and the end view of finished privacy slats 106 in FIG. 8 show the hollow cell profile extrusion configuration. Plat panels 130 of this configuration are available in 4×8 and 4×10 foot panels.
[0047] Using any of the printing techniques described, the decorative image can be readily scaled to the size of the privacy fence. Optionally, a UV resistant coating can be applied to the privacy slats 106 after laminating or printing to increase durability of the decorative privacy fence 100 . Another option is to apply a graffiti resistant coating, such as 3M Scotchcal High Gloss Graffiti-Resistant (polyester) Overlaminate 8912 ES, to the privacy slats 106 after laminating or printing.
[0048] The product may be provided in roll form as wire fence fabric with preinserted printed privacy slats or, alternatively, the printed privacy slats may be provided separately for insertion into the wire fence fabric in the field.
[0049] While the present invention has been described herein with respect to the exemplary embodiments and the best mode for practicing the invention, it will be apparent to one of ordinary skill in the art that many modifications, improvements and subcombinations of the various embodiments, adaptations and variations can be made to the invention without departing from the spirit and scope thereof. | A decorative privacy fence includes a wire fence fabric having a multiplicity of open vertical channels; a multiplicity of privacy slats inserted into the open vertical channels; and an image on the privacy slats with a portion of the image on each of the multiplicity of the privacy slats. The decorative privacy fence provides additional privacy by advantage of the eye's natural tendency to focus on an image that is presented to it. When the eye is focused on an image in the foreground, the background will be out of focus and will largely be ignored by the observer. By placing a decorative image on the surface of a privacy fence, the eyes will be drawn to the image and will focus on it. Even though the fence is not completely opaque, objects and activities behind the fence will be ignored by the casual observer. | 4 |
This is a division, of application Ser. No. 274,247, filed June 16, 1981, now U.S. Pat. No. 4,391,832.
BACKGROUND OF THE INVENTION
The invention relates to a process for making multi-layer cream-filled wafer blocks.
Wafer blocks are known in the food and biscuits and confectionery industry as intermediate products for mechanically produced wafer products. Among the various known wafer products are cookies and confectionery, for example, wafer cones, wafer cups, wafer plates, flat wafer discs, hollow croissants, wafer rolls, ice cream cones, filled wafers, ice cream wafers, wafer slices small cream filled wafer bars and the like. Wafer blocks are also known as a starting product for filled wafers, ice cream wafers, wafer slices small cream filled wafer bars and the like. All these wafer products are bakery products made from a wafer batter and having a crisp, brittle and easily breakable consistency.
The individual kinds of wafer products differ from one another in the type of manufacture. Thus, some wafer products are baked in their final form, as may be the case, for example, with wafer cones, wafer cups, wafer discs and the like. In the case of other wafer products, a wafer sheet or an endless wafer strip is first baked; and, in a baked but still soft state, the wafer sheet or strip is shaped into its final form. In this form the wafer product cools and assumes its crisp, brittle consistency. Examples of this are ice cream cones, hollow croissants, wafer rolls and the like.
For wafer products made from wafer blocks, several wafer sheets are baked, for example, in an automatic baking machine, cooled, coated with cream and formed into a stack. The cream-filled wafer block obtained in this way is then cut into small handy pieces of equal size. The resulting product then comes onto the market, packaged in units consisting of one piece or several pieces and, if appropriate, also packaged in an air-tight manner. Examples of wafer products of this type are cream wafer biscuits or cookies.
The various wafer products can be provided with coating such as, for example, of sugar or chocolate, or can be filled, for example, with edible ice, various creams, chocolate and the like.
Wafers of the present invention may at times be referred to as "waffles", but waffles baked in a waffle iron are to be distinguished from the above-described wafer products. The waffle iron product is a soft baked product analogous to a bread roll or pancake and, therefore, has no similarity at all in its consistency and usability to the above-described wafer products.
The invention, in particular, relates to a process for making multi-layer cream-filled wafer blocks, in which process cream-coated wafer sheets are conveyed in a first plane to a stacking point, where they are raised into a second plane and attached from below to the already raised part of the wafer block. Each coated wafer sheet is first pushed under that part of the wafer block which is held in the raised position, and then is raised. The wafer block thus formed is removed in the raised position from the stacking point.
In a certain process of this type, the wafer sheets are conveyed in succession to the stacking point on a single conveyor belt. On this conveyor belt, those wafer sheets which are to be provided with cream are coated by the contact coating process, the wafer sheets being conveyed away, spaced from one another, under a coating head located above the conveyor belt. When a wafer sheet is to remain uncoated, the conveyor belt is lowered, and the wafer sheet runs through under the coating head without contact therewith and is brought uncoated to the stacking point. Cream-filled wafer blocks can be made in this way if the cream can be applied to the wafer sheets by the contact coating process, since it is possible, in the contact coating process, to convey coated and uncoated wafer sheets on the same conveyor belt.
There are, however, creams which, because of their consistency, can only be applied to the wafer sheets by the film application process, or it is desirable for other reasons to apply the cream by the film application process. This may be the case, for example, when a further layer of cream is to be applied to a first layer of cream. In the film application process, the wafer sheets lying adjacent to one another on a conveyor belt are coated with cream by a film of cream being drawn off continuously from a roller by means of a blade and deposited onto the wafer sheets which are guided past underneath the roller by the conveyor belt. A belt located behind the conveyor belt and running at a higher speed separates the coated wafer sheets lying adjacent to one another, so that a sufficiently large distance arises between the wafer sheets to permit subsequent stacking. This belt, which runs at a substantially higher speed than the conveyor belt conveying the wafer sheets lying adjacent to one another under the cream application device, delivers the individual wafer sheets at intervals to a stacking device.
In the case of wafer sheets coated by the film application process, it is necessary either to deliver the covering sheet separately or to keep a wafer sheet free of cream by other measures.
There is also a process in which each wafer sheet is first raised in the stacking device and, as soon as the next wafer sheet is in position under the raised wafer sheet, the raised wafer sheet is allowed to drop onto it. In this process, although each wafer sheet is raised to form the stack, the raised wafer sheets are lowered onto the coated wafer sheet lying underneath, and the wafer sheets combined in this way are then raised again. The covering sheet is then deposited from its own conveyor belt onto the already assembled wafer block. Since the descent of the already raised wafer sheets before the next raising of the stack represents an additional process step, requiring a certain period of time, the efficiency of this process is limited.
In another apparatus for making cream filled wafer blocks by means of a single cream application device, the wafer sheets are coated with cream by the contact coating process on a feed belt before entry into a stacking device. They are then subsequently introduced into a vertical conveyor which consists of two screw tracks rotating about vertical axes. Uncoated wafer sheets are obtained by lowering the feed belt, since there is then no contact between the cream application device and the wafer sheet. However, this is not possible in the film application process, since the film is, of course, not interrupted by lowering the feed belt. Consequently, such apparatus cannot be used for making wafer blocks consisting of wafer sheets coated by the film application process.
SUMMARY OF THE INVENTION
The object of the invention is, therefore, to provide a process and apparatus, permitting the formation of blocks and unobstructed discharge of the complete wafer block even at the highest working speeds and even in the case of wafer sheets coated by means of a film.
In the process according to the invention, this is achieved by virtue of the fact that the covering sheet of the wafer block is delivered to the stacking point separately from the coated wafer sheets. Specifically, the covering sheet is directly deposited in a second plane which is in the stacking location in which the first coated wafer sheet is attached from below to the covering sheet. The apparatus for carrying out the process according to the invention includes a feed belt for the coated wafer sheets and a take-off belt which is provided, if appropriate, with a calibrating roller for the wafer block. Between the feed belt and the take-off belt is a vertical stacking device which raises the coated wafer sheets from a first plane into the second plane. The vertical stacking device has two screw tracks, i.e., helical tracks, lying opposite one another. These screw tracks are arranged as an extension of the feed belt and rotate in opposite directions about vertical axes. A movable stop is located in the direction of transport immediately behind the screw tracks. There is a conveyor device for the covering sheet, which conveyor device ends in the second plane before the screw tracks. This covering sheet conveyor is located above the feed belt.
By means of the process according to the invention and the apparatus for carrying this out, a very precise and rapid formation of a wafer block from wafer sheets coated by the film application process is made possible while as gentle a treatment as possible for the individual wafer sheets is attained. At the same time, one step of the process, namely the raising of the covering sheet, is saved, in comparison with the other process for wafer sheets coated by the contact coating process. This is accomplished by supplying the covering sheet in the second plane during the stacking of the wafer sheets. A greater efficiency results from this.
In other words, the process of the invention comprises the steps of: conveying, with a feeder conveyor, cream-coated wafer sheets in a first plane to a stacking point, the coated sheets having upper and lower sides with the cream coating being on the upper side, the coated sheets for any one wafer block including at least a first coated wafer sheet which is conveyed to the stacking point prior to any other coated wafer sheet; thereafter raising the coated wafer sheet into a second plane which is above the first plane and, by such raising, attaching the coated wafer sheet to the lower side of a wafer sheet in the second plane to form a wafer block which is in a raised position with respect to the feeder conveyor, the attaching being effected by the contact of the cream coating of the wafer sheet being raised with the lower side of an immediately adjoining sheet in the second plane. The process also includes the steps of thereafter removing the wafer block from the stacking point; and separately supplying, prior to the removing step, an uncoated covering wafer sheet for each wafer block, each covering sheet having an upper and lower side, the supplying being carried out such that the covering wafer sheet is delivered directly into the second plane at the stacking point and the first coated sheet is attached to the lower side of the covering sheet by raising of the first coated sheet into a position in which its cream coating contacts the lower side of the covering sheet which has been delivered into the second plane.
A further feature of the invention provides that the covering sheet is supplied in the second plane simultaneously with the first coated wafer sheet of the wafer block, the latter being supplied in the first plane. This measure ensures the saving of a further process step, in comparison with the other process, and, consequently, a further increase in efficiency.
In preferred apparatus for carrying out the process according to the invention, the conveyor device includes a chute which can be blocked by means of a movable barrier or the like. Here, it is advantageous for one wafer sheet in the chute to be always prevented by means of the barrier from sliding further so that, when a new wafer block is being formed, the barrier needs to be removed from the chute only briefly. This enables an uncoated wafer sheet to slide onto the vertical feeders (i.e., screw tracks or helical tracks) of the stacking device to detain the next wafer sheet sliding along in the chute. This design provides a particularly simple construction of the apparatus, in which the stacking device requires no special devices at all for the uncoated wafer sheet.
In other words, the apparatus of the invention comprises a feeder conveyor for moving cream-coated wafer sheets in a downstream direction in a first plane and a stacking device disposed adjacent to and generally downstream of the feeder conveyor for receiving cream-coated wafer sheets from the feeder conveyor and for stacking the wafer sheets vertically one under the other to form a wafer block, the stacking device having an upstream and downstream side. There is also a run-off conveyor disposed downstream of the stacking device for receiving completed wafer blocks discharged from the stacking device and for transporting such wafer blocks away from the stacking device. The stacking device includes means for: vertically lifting a cream-coated wafer sheet received from the feeder conveyor above the feeder conveyor and into a second plane which is above the first plane and for attaching the lifted cream-coated wafer sheet to the lower side of a wafer sheet in the second plane to form a wafer block which is in a raised position with respect to the feeder conveyor, the attaching being effected by the contact of the cream coating of the wafer sheet being raised with the lower side of an immediately adjoining sheet in the second plane. The apparatus also includes means for controlling discharge of the completed blocks from the stacking device and means for separately supplying an uncoated wafer sheet for each wafer block by delivering the covering sheet directly into the stacking device in the second plane so that a cream-coated wafer sheet is attached to the lower side of the covering sheet by raising of the coated sheet into a position in which its cream coating contacts the lower side of the covering sheet. This separate supplying means includes a covering sheet conveyor for conveying the uncoated covering wafer sheet in a downstream direction. The covering sheet conveyor has a terminal end region, the covering sheet conveyor being disposed above the feeder conveyor with its terminal end region ending in the second plane at the upstream side of the stacking device.
The stacking device includes a pair of vertical feeders for engaging and vertically raising the wafer sheets to effect stacking thereof, these vertical feeders comprising rotatable helical tracks (i.e., screw tracks) in the form of coiled, rod-like elements, the helical tracks providing an upward spiral movement, the helical tracks having axes of rotation. There is also means for rotatably driving the helical tracks in opposite rotary directions relative to one another.
Moreover, a further feature of the invention provides that the barrier is formed by a row of bristles, and a guide plate extending up to the row of bristles, is located in front of (i.e., upstream of) the barrier above the chute. This makes it possible to gently stop the wafer sheets which slide along. Thus, damage to the end edges by the stop is prevented.
Furthermore, according to the invention, the barrier may be embodied by a row of bristles. This barrier passes through the chute from below (i.e., from the lower side to the upper side), and the guide plate located above is at the shortest distance from the chute in the region of the row of bristles. In other words, the guide plate is spaced from the chute such that the distance between the guide plate and the chute is different at different points along the chute. This distance is the shortest in the region of the row of bristles.
It is thus possible for the covering sheet to pass partially between the guide plate and the row of bristles and, consequently, to be braked slowly.
Furthermore, the invention provides that at least the terminal end region of the chute is arranged parallel to the second plane defined by the screw tracks. As a result, an especially gentle delivery for the covering sheet is obtained.
The movable barrier may be formed by a plate which is mounted for pivoting movement about an axis parallel to the chute. The plate rests in the chute and is movable off from the chute.
It is further provided, according to the invention, that the stop, which is located immediately behind the screw tracks in the direction of transport, is arranged so that it can be displaced at right angles to the second plane formed by the screws tracks. In this case, it is advantageous that the part of the wafer block which has already been raised into the second plane rests against the stop over its entire height and, when a new wafer sheet is attached, slides along the stop by means of a side face.
The stop is part of a discharge controlling means disposed immediately downstream of the stacking device to provide a stop for each wafer sheet to prevent discharge thereof from the stacking device during stacking. This stop also provides an end guide for aligning the wafer sheets during stacking, the stop being vertically movable between an upper discharge blocking position above the run-off conveyor in which the wafer sheets in the stacking device engage the stop, a lower discharge position below the second plane in which the wafer sheets in the stacking device do not engage the stop and in which the completed wafer block is free to move downstream, and an intermediate vertical position above the second plane and below the main conveying surface of the run-off conveyor in which intermediate position the stop blocks downstream movement of the covering sheet in the stacking device. The discharge controlling means also includes a light gate disposed upstream of the stacking device for sensing the position of a wafer sheet, the light gate being operatively coupled with the stop for initiating lowering thereof, the light gate also being operatively coupled with the driving means for the helical tracks. The displacement of the stop is at right angles to the second plane.
The apparatus according to the invention is also distinguished by an extremely small space requirement. Thus, the length of a line of equipment for the production of wafer slices can be reduced considerably. In an apparatus according to the invention, the wafer sheets can also, if necessary, be coated with cream by the contact coating process without the advantages of the process according to the invention being lost as a result.
BRIEF DESCRIPTION OF THE DRAWING
The invention is described in more detail below with reference to an exemplary embodiment illustrated in the drawings for carrying out the process according to the invention.
FIG. 1 shows a section through the apparatus according to the invention along the line I--I of FIG. 2;
FIG. 2 shows a plan view of the apparatus according to FIG. 1;
FIG. 3 shows a section through the stacking device along the line III--III of FIG. 4;
FIG. 4 shows a plan view of the stacking device according to FIG. 3;
FIG. 5 shows a detail of the chute on an enlarged scale; and
FIG. 6 shows a detail of the left-hand portion of an apparatus similar to that of FIG. 7, but wherein a swinging plate barrier is used in place of a barrier of movable bristles.
DETAILED DESCRIPTION
The apparatus according to the invention consists of a stand 1, in which a feed belt (i.e., a feeder conveyor) 2, a stacking device 3 and a take-off belt (i.e., a run-off conveyor) 4 are located. The two belts 2, 4 each have a frame 5, by means of which they are mounted on the stand 1. A chute 6 for the uncoated wafer covering sheets is mounted above the feed belt 2. If appropriate, a calibrating roller (not shown) for the wafer block is mounted above the take-off belt 4. The chute 6 has a terminal end region 16 which ends above the feed belt immediately in front of (i.e., upstream of) the stacking device 3. As will be apparent from the drawing, the terminal end region 16 is adjacent one of the ends of the chute; i.e., terminal end region 16 is adjacent the terminal end of the chute. Of course, the terminal end of the chute is that end which the covering sheet passes when it has traveled along the length of the chute. Located above the chute 6 is a barrier 9 which can pivot about a horizontal axis and which can be raised from the chute or lowered towards the chute 6. Barrier 9 prevents a covering sheet lying on the chute from sliding further. The barrier may also be formed by a row of bristles 31 which can be removed from the sliding path of the wafer sheet and which can be raised from the chute at right angles thereto or lowered towards it. The chute 6 is inclined relative to the horizontal conveying plane of the feed belt 2 in such a way that, when the barrier or the stop is removed, the wafer sheet lying on the slide 6 slides along the chute 6 into the stacking device 3 as a result of gravity alone.
The base of the chute 6 may be provided with longitudinal slits 32, so that the covering sheet slides only on the webs remaining between the longitudinal slits. The barrier 9 in the form of a row of bristles can be located underneath the chute, so that the bristles pass through the base of the chute from below by way of the longitudinal slits. In the raised state, the bristles stand against a guide plate 30 located above the chute 6. The guide plate 30 is inclined towards the chute 6 and is provided, in the region of the row of bristles, with a curvature leading away from the chute 6, so that the distance between the guide plate 30 and chute 6 is shortest in the region of the row of bristles.
A covering sheet sliding along the chute 6 to the barrier 9 is detained very gently due to the formation of the barrier 9 as a row of bristles. This is because the covering sheet passes partially through between the guide plate 30 and the row of bristles and, in so doing, is braked. If the row of bristles is arranged above the chute 9 so that it can be raised relative to the latter, then the covering sheet is detained by being held between the base of the chute 6 and the row of bristles. The movable barrier may also be formed by a plate 22 which is pivotable about an axis parallel to the chute 6. (See FIG. 6.) Plate 22 rests on chute 6 and is movable off from chute 6.
The release of the uncoated covering sheet by, for example, lowering the row of bristles or lifting the pivotable plate 22, is controlled via a light barrier 10 located in front of the feed belt 2 and via an adjustable counter on which the number of wafer sheets of a wafer block can be set.
A cream application device (not shown) is located in front of the feed belt 2, in the direction of transport, above a conveyor belt (not shown) which conveys under the cream application device the wafer sheets which are to be coated and which lie adjacent to one another. In the region of the light barrier 10, the foregoing conveyor belt transfers the coated wafer sheets lying adjacent to one another to the feed belt 2 which runs at a substantially higher speed. As a result of this, the coated wafer sheets are separated from one another and are delivered to the stacking device 3 singly and spaced from one another. Because of the difference in the speed of conveyance of the coated wafer sheets which are conveyed lying adjacent to one another, on the one hand, and the speed of conveyance in the stacking device 3, on the other hand, the period of time necessary for the stacking operation itself is obtained.
The stacking device 3 consists of two screw tracks (i.e., helical tracks) 11, 11' which adjoin the feed belt 2 in the direction of transport and lie opposite one another and which can rotate about vertical axes and receive the wafer sheets between one another. The screw tracks 11, 11' consist of wire-shaped spring steel bent along a helix, the screw tracks 11, 11' rotating in opposite directions and being coiled in a sense opposite to their direction of rotation. In the screw track 11' on the right, looking in the direction of transport, the turns ascend in a counter-clockwise direction, and the screw track 11' rotates about its vertical axis 12' in a clockwise direction. In the opposite screw track, i.e., screw track 11 on the left, the turn ascend in a clockwise direction. The left screw track 11 rotates in a counter-clockwise direction about an axis 12 parallel to the axis of rotation 12' of the right screw track 11'. The distance of the screw tracks 11, 11' from the respective axes of rotation 12, 12' corresponds approximately to half the length of a wafer sheet 7, looking in the direction of transport. Each of the two screw tracks 11, 11' has only two turns and is fastened, by means of a diametrical arm 29, 29' to a shaft 26, 26' forming the axis of rotation 12, 12'. The arm 29, 29', as well as half to one turn of each screw track 11, 11', is located underneath the transport plane of the feed belt 2. When the screw tracks 11, 11' are stopped, the points where the two screw tracks 11, 11' first intersect the transport plane of the feed belt 2 are located outside the actual stacking region and substantially in the plane perpendicular to the transport direction and defined by the axes of rotation 12, 12' of the screw tracks 11, 11'. The distance between the axes of rotation 12, 12' of the two screw tracks 11, 11' corresponds to the width of one wafer sheet 7, increased by the diameter of one shaft 26. Under these conditions, an optimum support for the friable and easily breakable wafer sheet 7 is achieved.
The shafts 26, 26' of the screw tracks 11, 11' are mounted, at their respective lower ends, in a plate 13, fastened to the stand 1 of the apparatus. Each of the shafts 26, 26' is driven intermittently by its own motor 14, 14', so that the screw tracks 11, 11' perform only one revolution each time. The control of the motors 14, 14' and the design of the control are such that each of the screw tracks 11, 11' always stops in one and the same position after one revolution. It is ensured, in this way, that the wafer sheets do not butt against screw tracks 11, 11', but enter between them. As a result of driving the screw tracks 11, 11' with their own motors 14, 14' respectively, the space above or below the stacking device is kept free, so that any wafer blocks in which defective wafer sheets have been processed may be removed from the apparatus in a simple way by striking the wafer block with the edge of the hand between the screw tracks 11, 11', so that the wafer block breaks and falls down out of the stacking device. It is necessary, for this purpose, that the pitch of the screw tracks 11, 11' correspond to 2.5-4 times the thickness of the wire-shaped spring steel constituting the screw tracks 11, 11'. In this way, the fragments of the wafer block do not become jammed between the turns of the screw tracks. For the same reasons, the width of the wire-shaped spring steel constituting the screw tracks 11, 11' should also amount only to between one-hundredth and one-twentieth of the mean diameter of the screw tracks 11, 11'. Also, the effective part of the screw tracks 11, 11', that is to say, that part which projects above the transport plane of the feed belt 2, should consist of only one to one and a half turns. The upper end of the screw tracks 11, 11' is flattened.
To give the screw tracks 11, 11' more support, they are provided, on their parts located outside the actual stacking region, with one or more guides. These may include either of (1) an arcuate slit 27 between walls 25 opposite one another, or (2) several bars 28 or rotatably mounted rollers located alternately on the inside and on the outside of the screw tracks. The wall parts 25 delimiting the slit 27, and the bars 28 or rollers can appropriately be applied, separately from one another, against the screw tracks 11, 11'. The motors 14, 14' of the screw tracks 11, 11' are switched on by means of the same light barrier 10 which also controls the release of the uncoated wafer covering sheet on the chute 6.
The wafer sheets entering from the feed belt 2 between the turns of the screw tracks 11, 11' are conveyed up from a first plane 33, into which they are conveyed from the feed belt, into a second plane 34, from which the finished wafer block is discharged by means of the screw tracks 11, 11'. The screw tracks 11, 11' rotate in opposite directions and their turns raise the respective wafer sheets lying on the two screw tracks 11, 11' synchronously from the first plane into the second plane. During this process, certain components of forces which are transmitted to the wafer sheet as a result of the rotation of the screw tracks 11, 11' (i.e., forward components which point in the direction of transport) would tend to impart a forward movement of the wafer sheet in the direction of transport. To prevent this forward movement of the individual wafer sheets before the wafer block is finished, there is located immediately behind (i.e., downstream of) the screw tracks 11, 11' a stop 21 which consists of several fingers 20 fastened in a plate 30 and along which the wafer sheets 7 slide during the time that they are conveyed up by the screw tracks 11, 11'. Thus, the rotating screw tracks will slide relative to the wafers when the stop is in a blocking position. When the desired number of wafer sheets, which number has been set on the counter, has advanced into the stacking device 3, that is to say, when the last wafer sheet is still located in the first plane of the stacking device 3, then, when the first coated wafer sheet of the next block passes the light barrier 10, the first rotation of the screw tracks 11, 11' is triggered. As a result of this, the last wafer sheet of the block previously formed is attached to the latter from below. After this first revolution has been completed, the stop 21 descends. At the same time, the second revolution of the screw tracks 11, 11' is started without interruption.
As a result, the wafer block is released and is transferred from the screw tracks 11, 11' onto the take-off belt 4, during which time the stop 21 returns to its first position in which it remains with its top edge below the transport plane (i.e., the main conveyor surface) of the take-off belt 4. As soon as the screw tracks 11, 11' come to a standstill after the second revolution, the covering sheet in the chute 6 is released and slips onto the screw tracks 11, 11' and, therefore, into the second plane 34. At the same time, the first coated wafer sheet is pushed from the feed belt 2 into the first plane of the screw tracks 11, 11'. When the second coated wafer sheet passes the light barrier 10, the stop 21 moves into its upper, second position, and the first coated wafer sheet is applied from below to the covering sheet by the screw tracks 11, 11'.
The return of the stop 21 to its initial position in two steps is necessary because, when the finished wafer block is conveyed out of the stacking device 3 by means of the forward force component imparted by the screw tracks 11, 11', the wafer block is not moved beyond the region of the stop 21 by the screw tracks. It is only conveyed further by the take-off belt. Thus, if the stop were to return to its initial position immediately, the result would be that the tips of the fingers 20 of the stop 21 would slide along the bottommost wafer sheet of the wafer block to be discharged and would, in so doing, damage this wafer sheet.
The wafer block is pushed out by means of the screw tracks 11, 11' themselves by means of the auxiliary devices located in the interior of the screw tracks 11, 11' and by means of the take-off belt 4. The auxiliary devices comprise guide rollers 23 which grasp the wafer sheets or the wafer block at the edges parallel to the conveying direction of the belts 2 and 4. The shafts 26, 26' carrying the screw tracks 11, 11' are likewise formed as guide rollers. In this way, it is ensured that the finished wafer block has already left the stacking device 3 before the covering sheet of the next wafer block is introduced into the second plane of the stacking device.
The stop 21 is actuated by means of a compressed air cylinder 24 which engages on the plate 30 and which is likewise controlled by the light barrier 10 and the counter.
The guide rollers 23 are driven from the shaft 26 of the screw track 11 via V-belts or round belts 17. The guide rollers 23 of the auxiliary device are at a standstill when the wafer sheets are introduced. These guide rollers also have the function of ensuring that the individual wafer sheets are exactly aligned relative to one another and have the function of assisting the stacking device 3 when the wafer block is discharged from the latter. However, it is possible to have a drive of the guide rollers 23, which is independent of the drive of the screw tracks 11, 11'. With such a drive, the guide rollers can assist the feed belt 2 when the wafer sheet 7 is introduced into the stacking device 3.
The axles of the guide rollers 23 are mounted at their upper end in a gallows-like bracket 18. A stripper 19 is assigned to each of the guide rollers 23 and to the shaft 26 carrying the screw track 11 to prevent cream issuing from the sides of the wafer block from adhering to the guide roller 23 or to the shaft 26. The screw tracks 11, 11' themselves require no strippers, since they clean themselves automatically as a result of the relative movement with respect to the wafer sheets. The two guide rollers 23 can also constitute direction-changing rollers for a conveyor belt which fulfills the same functions.
According to a further alternative version of the invention, there can be provided a fixed second stop parallel to the movable stop.
This second stop projects above the second plane, but its top edge does not project above the transport plane of the drive belt 4. This second stop projects somewhat, with respect to the movable stop, towards the stacking device 3. When the movable stop is lowered below the transport plane of the take-off belt 4 in order to discharge a finished wafer block from the stacking device 3 and after the last coated wafer sheet has been attached to this wafer block, then, during the time that the finished wafer block is conveyed out of the stacking device 3, the covering sheet of the next wafer block and at the same time its first coated wafer sheet come to rest against the fixed stop. This is so that the movable stop can return to its upper end position without, in so doing, touching the end edges of the first two wafer sheets of the next wafer block, which are already located in the stacking device 3. When the first coated wafer sheet of the next wafer block is raised by means of the stacking device 3 out of the first plane into the second plane and is thereby applied from below to the covering sheet already located in the second plane, the two wafer sheets slide along the fixed stop and only come to rest against the movable stop just below the transport plane of the take-off belt. The wafer sheets then slide further up along this movable stop while further coated wafer sheets are attached.
The mode of operation of apparatus according to the invention is described in more detail below with reference to the formation of a five-layer wafer block.
The coated wafer sheets are conveyed by a conveyor device (not shown), for example, a conveyor belt of the cream application device, to the light barrier 10. The uncoated covering sheets arrive, via the chute 6, in front of the barrier 9.
As soon as the first coated wafer sheet of the new wafer block to be made has passed the light barrier 10 and is transferred to the feed belt 2, a signal is triggered at the light barrier 10. This causes, by means of a control which, if necessary, works with a time delay, a lowering of the barrier 9 from the chute 6. This further causes a consequent release of a covering sheet and the immediate switching on of the drives of the screw tracks 11, 11'.
The latter perform one complete revolution, by means of which the last coated wafer sheet of the preceding wafer block is raised and is applied from below to the other wafer sheets which are already joined to one another. After the screw tracks 11, 11' have performed the one complete revolution, the stop 21 is lowered into its bottommost position, and the drives of the screw tracks 11, 11' rotate the tracks further through a second complete revolution. As a result, the preceding finished wafer block is pushed by means of the guide rollers 23 onto the constantly running take-off belt 4 and is conveyed by the latter out of the region of the screw tracks 11, 11'.
In the meantime, the stop 21 ascends one step. After the second complete revolution of the screw tracks 11, 11', their drives are switched off. Only then is the first coated wafer sheet of the new wafer block pushed by the feed belt 2 into the lower turn of the two screw tracks 11, 11' which has become free. At the same time, with the screw tracks 11, 11' at a standstill, the covering sheet released by the barrier 9 passes via the chute 6 into the upper turn of the two screw tracks 11, 11' and comes to rest against the stop 21.
After the preceding wafer block has been discharged by the take-off belt 4 and the stop 21 has been raised into its upper end position, and when the second coated wafer sheet of the new wafer block to be made passes the light barrier 10, the screw tracks 11, 11' are made to rotate again. As a result of this, the first coated wafer sheet of the new wafer block is raised and attached to the covering sheet. After the screw tracks 11, 11' have been stopped, the second coated wafer sheet of the wafer block enters the lower turns of the screw tracks 11, 11'. The second coated wafer sheet is raised as soon as the third coated wafer sheet passes the light barrier 10. The latter wafer sheet is attached to that part of the wafer block to be made which is already in the raised position when the fourth and last coated wafer sheet of the wafer block having five wafer sheets passes the light barrier 10. This last wafer sheet enters the lower turns of the screw tracks 11, 11' after the latter have been stopped, and therefore after the third coated wafer sheet has been attached. As already described, this last wafer sheet is raised when the first coated wafer sheet of the next wafer block passes in front of the screw tracks 11, 11'. | Cream-coated wafer sheets are conveyed by a feeder conveyor in a first plane to a stacking device. The coated wafers are raised in the stacking device into a second plane and by such a raising are attached to the lower sides of a wafer sheet already in the second plane to form a wafer block which is in a raised position with respect to the feeder conveyor. An uncoated covering wafer sheet is separately supplied to each wafer block such that the covering sheet is delivered directly into the second plane at the stacking point, and a coated sheet is attached to the lower side of this covering sheet by raising up into a position in which its cream coating contacts the lower side of the covering sheet. This separate, direct supply of the uncoated covering wafer sheet is effected by a covering sheet conveyor disposed above the feeder conveyor. The terminal end region of the covering sheet conveyor ends in the second plane at the upstream side of the stacking device. | 1 |
This is a continuation in part of patent application Ser. No. 202.908 filed on Nov. 3, 1980, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to a drive system for road vehicles, in particular public transportation and semitrailer vehicles.
Several hydrodynamic or oil-operated drive systems are currently known and marketed, all such systems being referred to hereinafter as "hydraulic drive systems", as known are advantages afforded thereby. For transmitting motive power on transportation vehicles, such hydraulic drive systems have gained acceptance mainly on account of their inherent ability to provide a continuously variable drive ratio and independent control of the speed and torque delivered to each driving wheel. To accomplish the former goal, hydraulically operated units have been developed for installation in lieu of the clutch/transmission assembly employed in traditional drives. The latter goal is instead achieved by providing a pump to feed a number of hydraulic motors, each motor being coupled to one wheel of the vehicle.
While the former systems is mainly directed to making the driving of the vehicle more convenient, as an alternative to fully automated transmissions, the latter has substantial advantages from the standpoint of engineering and economy, and is generally preferred for industrial vehicles. Moreover, the latter system affords the additional advantage of eliminating the need for differential gears and driveshafts, such that, at least in principle, it may be reduced to but one pump and two or four hydraulic motors.
However, traditional power drive systems have been definitely improved through the years, especially as relates to automatic transmissions and differential gears. Thus, the technical problem arises of investigating whether novel and particularly advantageous combinations may be found among the hydraulic drive units and mechanical drive units.
SUMMARY OF THE INVENTION
This invention sets out to solve the aforesaid technical problem by providing a novel hydraulic and mechanical drive system for road vehicles, which at least in specific conditions can be more advantageous than conventional drive systems.
More specifically, the invention is directed to providing a drive system which is particularly suitable for application to public transportation vehicles, especially vehicles of the semitrailer type.
According to one aspect of the present invention, there is provided a power drive system for road vehicles of the type having at least one differential gear for the driving wheels and which comprises serially arranged to one another, at least one prime motor, at least one hydraulic pump driven by said prime motor, and at least one hydraulic motor connected to said hydraulic pump through conduit means, and is characterized in that it comprises transmission means drivingly connecting said at least one hydraulic motor with said differential gear.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of the invention will be detailed hereinafter through a description of a presently preferred embodiment thereof, with reference to the accompanying drawings, where:
FIG. 1 is a hydraulic diagram of the drive system according to the invention;
FIG. 2 shows a drive system, as illustrated diagrammatically in FIG. 1, as installed on the frame of a public transportation vehicle of the semitrailer type, of which vehicle frame only the rear portion and part of the front portion are shown;
FIG. 3 is a function and hydraulic diagram of the inventive system;
FIG. 4 is a side view, partially in section of the brake or throttle pedal with the associated controls;
FIG. 5 is a sectional view taken along line V--V of FIG. 4 of the throttle or brake controls;
FIGS. 6 and 7 are front view of details of FIG. 5;
FIG. 8 is a perspective and exploded view of a detail of FIG. 3; and
FIG. 9a-9e are schematic diagrams of the fluid path between pumps and motors of FIG. 3 in five different running conditions of the vehicle.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With particular reference to FIG. 1, the drive system according to the invention provides in essence, and particularly for a vehicle having two drive axles, a prime motor 1, such as an internal combustion engine, driving a hydraulic pump 2 which coverts the energy generated by said engine into pressure fluid energy. In parallel therewith, there is provided an electric primary motor 3, perferably of the constant speed type, which drives, in turn, a hydraulic pump 4 of its own, identical to the pump 2 and which in turn converts the energy generated by said electrical motor into pressure fluid energy. The two pumps, 2 and 4, are respectively connected, through dual, delivery and return, first lines or ducts 5 and second lines or ducts 6, to a distributor valve unit 7 feeding in parallel, through third lines 8 and fourth lines 9, also of the dual type, respectively the two hydraulic motors 10 and 11. Such hydraulic motors are each mounted on a differential gear 12 and 13, respectively, which rotatively drive pairs of driving wheel sets, 14 and 15, through axle shafts 16 and 17.
FIG. 2 illustrates, in a topographic and schematic manner, the arrangement and location of a hydraulic system, in accordance with the layout diagram of FIG. 1, across the frame of a public transportation vehicle of the semitrailer type which has two driving axles and includes an internal combustion engine type of prime motor, e.g. a diesel engine, for self-propulsion, and a primary electric motor for operation as a trolleybus or tramcar. Corresponding parts in FIGS. 1 and 2 are designated with the same reference numerals.
The semitrailer vehicle of FIG. 2 is generally indicated at 20. Reference has been made, for illustrative purposes only, to a three-axle type of semitrailer vehicle, of which only the two rear axles are shown in the figure. There may be seen a load bearing or main frame 21 comprising two sections or body portion structures articulated to each other by a rotary ring or plate or "fifth wheel" 22, known per se, e.g. as manufactured and sold by SCHENK of Stuttgart, West Germany. The rear section or body portion mounts the prime motor 1 and primary motor 3: in particular a latticework structure 21a accommodates in internal combustion engine constituting the prime motor 1, whilst between the fifth wheel 22 and the driving wheel sets 14 there is accommodated the electric primary motor 3. The front body portion of the frame, mounting the steering wheels, is not shown in the drawing and may be set up in a manner known per se.
The motors 1 and 3, hydraulic pumps, and hydraulic motors, are all located between two parallel side spars 23 and 24, which extend from the fifth wheel 22 both towards the front section and rear semitrailer, wherefor they form the supporting framing, in a quite conventional manner. The passenger-carrying coach is positioned on both frame sections or portions.
The hydraulic motors 10 and 11 are mounted directly over the differential gears 12 and 13, and are swingable therewith. Alternatively a cardan shaft connection (not shown) may be provided between the hydraulic motors 10,11 and the differential gears 12,13 respectively.
As shown in FIG. 2, connections 25 are led to the valve unit 7, as well as the prime motor 1 and primary motor 3, which interconnect these elements with the throttle and brake controls at the driver's station shown in FIGS. 4-7. In such figures only the throttle controls are shown, the brake controls being the same. As it may be seen from these figures, the throttle controls consist essentially of a rack 30 connected with an end thereof to the throttle pedal 31, a gear 32 meshing with the rack 30, a driving shaft 33 fixed to the gear 32 and rotatable therewith, cams 34 fixed to the driving shaft and acting on microswitches 35, and a rheostat 36. The connection between the throttle pedal 31 and the rack 30 shown in the form of a slotted lever hinge connection may be of any type, provided that, when the pedal 31 is pressed by the utilizer's foot, the rack moves downwardly, whereas when the driver releases the action on the pedal, the rack is moved upwardly by the action e.g. of a spring (not shown). The longitudinal movement of the rack causes a rotation of the gear 32 and of the herewith connected driving shaft 33 in counterclockwise or clockwise, according to whether the pedal has been pressed or released, respectively. Consequently also the cams 34 are rotated and brought out of or in engagement with the microswitches 35, as it may be seen from FIG. 6. The microswitches 35 are connected by means of leads 25 to the valve unit 7 and are intended the first one to allow the electronic circuits of the valve unit 7 to begin the swept volume control, and the second one is for security functions: in fact the valve unit always controls that, when the brake pedal is actuated, the throttle controls have been returned to their rest position. Furthermore the vehicle is permitted to start only if the electronic circuits of the valve unit 7 have received all the signals stating that the vehicle doors have been closed, the air pressure is at the desired value, the engine bonnet is closed, and so on.
The rheostat shown in the drawings is of the type with a contact 38 fixed to the driving shaft 33 and sliding on the coils 39 of the rheostat, so that the electric path of the current between the input and the output leads 25 and consequently the intensity of the signal fed to the valve unit 7 and motors 1,3 can be varied according to the position of the pedal 31. By means of the rheostat 36 it is possible to vary the cylinder capacity of the pumps and of the motors in order to increase or decrease the speed of the vehicle. When the pedal 31 is released, a spring not shown causes the return of the pedal 31, the rack 30 is moved upwardly and the cams 34 are brought in engagement with the microswitches 35.
For the brake controls the operation is the same, whereas, when the vehicle operates as trolleybus or tramcar, and the brake pedal has been pressed, the first microswitch sends an electrical signal which causes the electric braking to start. On the contrary, the second microswitch has the function of preventing the simultaneous actuation of the brake and of the throttle controls and sends an electric signal to valve unit 7 for this purpose.
The unit 7 controls the liquid flow being circulated, both for starting and braking purposes, by acting on the hydraulic pumps 2,4, and on the hydraulic motors 10,11. Moreover, the unit 7 includes a change-over device, which is operative to prevent the simultaneous actuation of the motors 1 and 3. More specifically, the unit 7 is only ideally, for convenience of illustration, shown as a unitary construction. In actual practice, the various elements which concur to the functions of the unit 7 may be scattered throughout the vehicle structure, while remaining operatively interconnected. In essence, besides the cited change-over device, such elements may be divided into: electric control devices 7a, solenoid valve devices 7b, and electric control devices 7c.
The electric control devices 7a are sensors adapted for detecting the vehicle travel condition parameters (e.g. the wheel rpm's, the rpm's of the prime motor when in operation, the road gradient, the oil pressure and temperature, etc., in the various circuits) and feeding respective electric signals to the electric control devices 7c.
The solenoid valve device 7b consists of a perforated plate 40 (illustrated in detail in the exploded view of FIG. 8) and two equal solenoid valves 41 represented only schematically in FIG. 3 (according to the symbols used in "Glossary of fluid power terminology" Fluid Power Society, 1969, pg. 219) and which working positions are illustrated in FIG. 9a-9e for different running conditions of the vehicle.
With reference to FIG. 8, the perforated plate 40 is devided into two parts: a first part 40a (on the left in the drawing) connected to the pump 2 of the internal combustion engine 1, and a second part 40b (on the right) connected to the pump 4 of the electric motor 3. The two parts are symmetric and present a plurality of internal channels opening on the lateral and lower surfaces of the plate. In detail the left-hand part 40a presents a first elbow channel 45a opening with an end thereof on the front surface 42, where it is jointed to the delivery line 5a (FIG. 3), and with the other end thereof on the lower surface 44 at the opening P 1 of the valve 41a; and a second elbow channel 46a opening with an end thereof on the front surface 42, where it is jointed to the return line 5b (FIG. 3), and with the other end thereof on the lower surface 44 at the opening T 1 of the valve 41a. In the left-hand part 40a there is also provided a linear channel 47a, opening with an end thereof on the front surface 42 and here connected to the line 8a (FIG. 3) and with the other end thereof on the rear surface 43 and here connected to line 9a, furthermore the channel 47a presents a channel branch 48a opening on the lower surface 44 at the opening A 1 of valve 41a. The right-hand part 40b is provided with channels 45b; 46b, 47b and 48b analogous to those of the left-hand part, whereas channel 45b is jointed to delivery line 6a and opens at P 2 , channel 46b is jointed to return line 6b and opens at T 2 , channel 47b is connected to lines 8b and and 9b, channel 48 opens at B 2 .
The plate 40 is also provided with a two-elbow channel 49, extending between the left-hand and right-hand parts 40a and 40b and opening on the lower surface 44 and B 1 with an end thereof and at A 2 with the other end thereof. In FIG. 8 arrows illustrate the flowing direction of the fluid, whereas double arrows indicate that the fluid can flow in either directions for direct and reverse motion respectively, as it will be explained more fully hereinafter with reference to FIG. 9a-9e.
The solenoid valves 41a, 41b, which when the valve device 7b is assembled, are fixed to perforated plate 40 such that their openings A,B,P,T are jointed to the channels of plate 40 in the manner above described, are of the type in which an internal cursor or slide (not shown), operated by magnets, cuts off or permits communication between the openings on the base of the signals received on the leads 50 from the electric control devices 7c. Such solenoid valves for example those manufactured by KRACHT and on the market under the name WL 4.20, are well known in the art, so that they will not be described in detail.
The electric control devices 7c receive signals from both said electric control devices 7a, and the controls located at the driver's station as explained with reference to FIGS. 4-7. The signals are processed, and so converted as to control both the position of the solenoid valves 7b and the flow rates of the hydraulic pumps 2 or 4 and hydraulic motors 10 and 11. In fact, the system according to this invention may include advantageously hydraulic motors 10 and 11 and hydraulic pumps 2 or 4 of the variable swept volume type or variable flow rate type, that is wherein the rpm's and flow rate (at constant rpm's) can be changed independently.
The electric control devices 7c consist of a plurality of electronic circuits mounted on cards and comprising integrated elements (static logic) but should also comprise a computer or microprocessor which, on the basis of a program, controls the state of different inputs and sends control signals to the pumps 2 and 4 in order to vary the oil quantity delivered therefrom and to the solenoid valve devices 7b in order to change over the different functioning mode thereof.
The net result is that, whereas the rpm's of the pumps 2 or 4 and motors 10 and 11 are respectively dictated by the rpm's of the prime motor 1 and primary motor 3, which are directly controlled by the driver, and the amount of oil being circulated through the lines 8 and 9, the flow rate or swept volume of said pumps and motors is controlled by the electric control devices, both in accordance with the driver's own decisions and of the running conditions detected by the electric devices 7a.
FIG. 3 illustrates the operation of the drive system as described hereinabove, the unit 7 being subdivided into said portions 7a, 7b, 7c, there being shown in addition to the hydraulic diagram already shown in FIG. 1, also mutual interactions, as indicated in dotted lines, between the various members.
FIG. 3 indicates also the flowing path of the fluid between pumps 2,4 and motors 10,11, whereas continuous arrows illustrate the flow direction in case of direct motion of the vehicle (where only one motor, either internal combustion engine 1 or electrical engine 3 is active) and dotted arrows illustrate the flow direction in case of reverse motion (the flow between pumps 2 or 4 and valve 7b occurring only in one and the same direction, the dotted arrows have not been illustrated). More details about the flowing path can be got from FIG. 9a-9e, with schematically show the positions of valves 40 when the motors 10,11 are short-circuited, in case of direct motion driven by the electric engine 3, in case of direct motion driven by the internal combustion engine 1, in case of reverse motion driven by the internal combustion engine 1 and in case of reverse motion driven by the electric engine 3, respectively. Referring now to FIG. 9a, the inoperative pumps 2, 4 are shut off, whereas the hydraulic motors 10,11 are short-circuited. In this case the opening A 1 is connected to the opening B 1 and the opening A 2 is connected to the opening B 2 . This position of valves 41 is selected in case of failure, when the vehicle must be towed and, in order to allow the movement of the wheels of the same, the fluid must circulate in the motors 10,11.
FIG. 9b refers to the direct motion driven by the electric engine 3: in this case the opening P 2 is connected to opening A 2 and opening B 2 is connected to T 2 , whereas the pump 2 is shut off and opening A 1 and B 1 are directly connected. Whereas the flow direction is indicated by arrows, the hydraulic motors 10,11 have only been illustrated in FIG. 9a and has not been indicated in FIGS. 9b, 9c, 9d, 9e for easiness. FIG. 9c corresponds to the case of direct motion driven by the internal combustion engine 1: the pump 4 is now shut off, opening P 1 is connected to A 1 and opening B 1 is connected to T 1 , whereas opening A 2 and B 2 are directly connected. In FIG. 9d the flowing path of the fluid is illustrated in case of reverse motion driven by the internal combustion engine 1. As it may be seen, in this case the flow direction between hydraulic motors 10,11 and valves 41 is reversed, opening P 1 is connected to B 1 , opening A 1 is connected to T 1 , openings A 2 and B 2 are directly connected and the electric engine pump 4 is shut off. On the contrary in FIG. 9e (representing the case of reverse motion driven by the electric motor 3), opening P 2 is connected to B 2 , A 2 is connected to T 2 and A 1 , B 1 are directly connected between themselves. The pump 2 is here shut off.
In practice, the road vehicle is jointly placed under control by the driver, who will control the prime motor 1 and primary motor 3 directly, and by the unit 7 which will control the power delivered to the differentials 12 and 13 in accordance with the running conditions of the vehicle and the driver's decisions.
By way of example, and in order to show how the invention can be implemented by utilizing readily available means, the internal combustion engine prime motor 1 may be a Magirus-Deutz V-8 diesel engine of 256 HP, while the primary electric motor 3 may be a Marelli motor developing 190 KW at 2600 rpm's and the hydraulic pumps 2 and 4 may be of the Linde BPV 100 model type, while the hydraulic motors 10 or 11 may be of the Linde BMV 105 model type, the vehicle frame may be a Fiat 470 main frame, and the differentials 12 or 13 may be a Fiat differential gear with a 1:12 gear ratio.
The advantages afforded by this drive system may be summarized as follows.
The fact should be considered first that the problems inherent to the drive train ending with the drive axles are effectively solved without involving any alteration of readily available and proven assemblies. This is particularly important for semitrailer vehicles, where the driveshafts pose serious installation and operation problems, owing to the long distances, sharp bends, and likelihood vibration involved.
Another advantage is that in the drive system of this invention, it is easy to optimize the distribution of the torque to the axles, the differences among such torques being relatively small. The torque distribution between the inside and outside wheels in a bend is instead practically accomplished through the differential gear, where the rpm's are dictated by the steering radium rather than by the torque, which instead adjusts itself to the demand.
Therefore, the invention achieves a maximum in economy optimization, while leaving unaffected the behavior of the vehicle in a bend. Finally, with the electric motor operating at a constant speed, no pick up power need be applied at each start in the case of the trolleybus application. Accordingly, the power requirements on the mains can be reduced drastically.
By way of example, a single embodiment has been described, but the invention is not limited thereto, neither as relates to the type of vehicle, nor to the number of the axles involved or provided. For instance, a two-axle vehicle may be contemplated, wherein a single, either Diesel or electric, prime motor is preferable, each hydraulic motor being then connected to its related differential gear through a conventional driveshaft set up in a similar manner to conventional road vehicle shafts. | A power drive system for road vehicles comprises, in series relationship, at least a prime motor, at least a hydraulic pump driven by the prime motor and at least one hydraulic motor connected to the hydraulic pump and driving a differential gear interposed between the hydraulic motor and a respective pair of driving wheels. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority upon U.S. provisional application Ser. No. 61/017,946, filed Dec. 31, 2007. This application is hereby incorporated by reference in its entirety for all of its teachings.
BACKGROUND
[0002] The ability to mark roadways and other concrete or asphalt substrates provides a useful way to convey information and instructions. A number of different techniques are currently in use for affixing markers and indicators to pavement. For example, liquid painted markings can be applied to the road surface with the use of brushes, rollers, or by motorised portable spray machines. Although efficient with respect to the application of the paint to the surface, there are several disadvantages. The thin coating requires time to cure. Moreover, the thin coating does not have a long life expectancy and is, thus, not very durable. At times, additional coats of paint are required to build up durability.
[0003] Adhesive tapes are made from semi rigid materials with a pressure sensitive adhesive for sticking to the road surface. This material does not adhere to the surface very well, which permits moisture to penetrate under the marking and weaken the bond between the tape and the road surface. Additionally, once an edge of the tape is loose, the marking is pulled away from the surface by oncoming traffic.
[0004] Another approach involves the use of preformed thermoplastic markers. Preformed thermoplastics can be pre-cut into different shapes and sizes. In certain situations, the thermoplastic material is placed on the road surface and heated with a propane torch to melt the material onto the road surface. This relies on the application of complete heat coverage to ensure 100% bonding to the road. If bonding is incomplete, the unbonded material will break up under passing traffic and the marking will fail. Moreover, if the road surface is damp or wet, the heat from the torch causes moisture to be drawn up to the underside of the marking, which can reduce the strength of the adhesive bond.
[0005] In other applications, thermoplastic markers can be applied to road surfaces without the use of heat. In these applications, an adhesive is on the underside of the pavement marker protected by a release liner. The release liner is peeled from the adhesive and the marker is pressed directly to a clean pavement surface. If necessary, it is rolled down after application to ensure a good bond to the pavement. However, the marker is generally not very durable.
[0006] Thus, what is needed are durable markers that can be easily applied to substrates such as pavement. It is also desirable that the marker is capable of receiving paint for producing a variety of different logos, words, lines, and other useful information. The systems and methods described herein address these needs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying FIGURE, which is incorporated in and constitute a part of this specification, illustrates one aspect described below.
[0008] FIG. 1 shows the side-view of a flexible marking system described herein.
SUMMARY OF EMBODIMENTS
[0009] Described herein are flexible marking systems possessing one or more painted images. The systems comprise a carrier layer adjacent to the adhesive layer, where the carrier layer is capable of receiving paint to produce painted images. The systems described herein are durable with respect to retaining the painted image. The systems are also durable with respect to remaining on the substrate once applied to the substrate. The systems do not require the use of heat and other expensive equipment for applying the system to the substrate.
[0010] The advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the aspects described below. The advantages described below will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive.
DETAILED DESCRIPTION
[0011] Before the present compounds, compositions, and/or methods are disclosed and described, it is to be understood that the aspects described below are not limited to specific compounds, synthetic methods, or uses as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.
[0012] In this specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings:
[0013] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a surfactant” includes mixtures of two or more such surfactants, and the like.
[0014] Described herein are flexible marking systems that can be adhered to a substrate. In one aspect, the system comprises:
a. an adhesive layer comprising a first surface and a second surface; b. a carrier layer comprising a first surface and a second surface, wherein the first surface of the carrier layer is adjacent to the second surface of the adhesive layer, and the second surface of the carrier layer can receive one or more painted images; and c. at least one painted image on the second surface of the carrier layer.
Each component of the system as well as the methods for making and using the systems will be discussed below.
[0018] An exemplary system described herein is depicted in FIG. 1 . Referring to FIG. 1 , system 1 is composed of an adhesive layer 10 and carrier layer 20 . The adhesive layer and carrier layer are adjacent to one another (i.e., intimate contact). Methods for applying the carrier layer to the adhesive layer will be described below.
[0019] The adhesive layer is generally a pressure sensitive adhesive. The use of heat or solvents is not necessary to secure the adhesive (and the system) to the substrate. Pressure sensitive adhesives are known in the art. For example, acrylics can be used as the adhesive layer. In one aspect, the adhesive layer comprises bitumen. Bitumen includes asphalt, asphaltites, mineral tars, mineral waxes, and polycyclic aromatic hydrocarbons. Bitumen has thermoplastic properties, which is desirable in outdoor applications when there are significant changes in temperature. The bitumen can be modified such that its thermoplastic properties are changed. For example, flux oils or volatile oils can be admixed with the bitumen. Alternatively, synthetic or natural polymers can be added to the bitumen. These polymers can modify certain properties of the bitumen including, but not limited to, softening point and brittleness. In one aspect, the bitumen is modified with styrene butadiene styrene (SBS).
[0020] In certain aspects, the adhesive layer further comprises a reinforcing fiber. The reinforcing fiber can be incorporated in the adhesive layer in a number of different ways. In one aspect, referring to FIG. 1 , the reinforcing fiber 11 can be sandwiched between two layers of adhesive 12 and 13 ( FIG. 1 ). The reinforcing fiber provides mechanical strength to the system and permits removal of the system from the substrate if needed. Additionally, the reinforcing fiber permits the easy removal of the system from the substrate. For example, the system can be slightly heated while pulling one edge of the system with a gripping tool. This results in the system being removed in one piece without any residual adhesive layer being left on the substrate. The reinforcing fiber can be prepared from woven and nonwoven materials including, but not limited to, polyesters, polyamides, polyalkylenes, or polyvinyl compounds. In one aspect, the reinforcing fiber comprises glass fibers including, but not limited to, glass meshes manufactured by GlasGrid.
[0021] The thickness of the adhesive layer is such that there is sufficient adhesive to adhere the carrier layer and to the substrate of interest. In the case when the system is applied to roads and flooring materials, the thickness of the adhesive layer and the system should be as small as possible in order to avoid tripping by pedestrians. In one aspect, the adhesive layer has a thickness less than 40 mils. In one aspect, adhesive materials sold under the tradenames ICE & WATER GUARD and RAINPROOF™ manufactured by Protecto Wrap can be used as the adhesive layer.
[0022] As shown in FIG. 1 , the carrier layer 20 is adjacent to the adhesive layer 10 . In one aspect, the carrier layer is a fibrous material capable of receiving paint. Not wishing to be bound by theory, the carrier layer comprises a matrix that can entrap the paint and other materials. Thus, when the paint is applied to the carrier layer it is not just a mere surface coating. By incorporating paint within the matrix, the durability of the resulting painted image increases. Additionally, the carrier layer provides mechanical strength to the system by keeping the adhesive layer in place. The fibrous material can be composed of a variety of woven fibers including, but not limited to, polyesters, polyamides, polyalkylenes (e.g., polypropylene, polyethylene), and rubber (natural and synthetic). In another aspect, the carrier layer is composed of a woven material or mesh of glass fibers. For example, C20U/2 and C35U/2 fiberglass sold by Owens Corning can be used as the carrier layer. Alternatively, the carrier layer can be a film composed of a polymeric material that can receive the paint. The film can be composed of any of the materials described above. Alternatively, the carrier layer can be pressure sensitive adhesive that is different from the adhesive present in the adhesive layer.
[0023] Additional components can be incorporated into the systems described herein. For example, a removable protective layer can be adjacent to the first surface 14 of the adhesive layer. The protective layer can be readily peeled from the adhesive layer when the system is ready to be applied to the substrate of interest. In another aspect, one or more anti-slip materials can be applied to the carrier layer. In one aspect, the anti-slip materials are applied to the carrier layer after the image is painted on the carrier layer. In this aspect, the paint helps adhere and trap the anti-slip materials in the carrier layer matrix. Examples of anti-slip materials useful herein include, but are not limited to, glass, quartz, non-vitreous ceramic, carbide (silicon and boron), aluminum oxides, sandstone, pumice, calcium silicates, aluminum silicofluoride, and aluminum sesquioxide. The size and amount of the anti-slip materials that are used will vary depending upon the selection of the carrier layer and the application of the system.
[0024] Methods for making the systems described herein are described below. In one aspect, the method comprises:
a. applying a carrier layer having a first surface and second surface to an adhesive layer, wherein the adhesive layer is adjacent to the first surface of the carrier layer; and b. painting an image on the second surface of the carrier layer.
[0027] With respect to the manufacture of the adhesive layer, the adhesive is fed into a heated trough, which has a number of rollers. In the case when a reinforcing fiber is used, the fiber sheet can be continuously fed into the trough and coated on both sides with the adhesive. Before exiting the trough, the coated fiber sheet passes through two squeeze rollers to set the thickness of the adhesive layer. These squeeze rollers are protected by a film of polyethylene, polypropylene, silicon paper or the like, which not only stop the adhesive from sticking to the rollers but also act as an interleaving film for the finished adhesive roll. In one aspect, one of the polymeric films can be replaced with a fabric or film to laminate the fabric or film on the adhesive layer to produce the carrier layer.
[0028] After the carrier layer is secured to the adhesive layer, it is ready to receive the painted image. In one aspect, the system is fed by a conveyor to a paint station. The paint station can be composed of a series of spray heads that spray paint on the carrier layer. The rate or pressure of the spray guns, screen print, roller or coater can determine the thickness as can the speed of the moving conveyor. Alternatively, the paint can be applied on a stationary platform. For images that require various colors such as disabled logos, warning signs, corporate logos, and the like, the paint can be applied by screen printing, airbrush spraying, stenciling, printed or other similar methods. In certain aspects when an anti-slip material is used, the anti-slip materials can be sprinkled over the wet system. After the paint has been applied, the system can be passed through a drying system and the resulting cured sheet is then rolled into suitable lengths for future slitting into widths for lines or sheets that are to be cut into shapes and legends.
[0029] The paint can be formulated to be fast drying. Typical paint compositions are water based, solvent based and polyurethane based. Water based paint is a non-flammable, lead-free, fast drying paint that is a available in all colors and is usually categorized by dry time and film thickness and are low VOC products. Solvent based paint comes in high and low viscosity chlorinated rubber, fast and regular dry alkylated, and regular and low VOC acrylic copolymer. These fast-drying paints are useful for highways, parking lots, crosswalks, stop bars, and legends. Polyurethane based paints are a homogeneous blend of polyurea resins and pigments and may contain reflective glass beads and anti-slip aggregates.
[0030] In certain aspects, the marking system can have a plurality of holes, where the holes penetrate the adhesive layer and carrier layer. Not wishing to be bound by theory, the holes permit any trapped air under the marking to escape when the marking is applied to the substrate. By doing this, the formation of air pockets or bubbles trapped between the marking and the substrate surface can be avoided. Air pockets can cause problems by either breaking the adhesive bond with the substrate or causing expansion due to elevated temperatures and possible delamination of the marking from the substrate surface. Over time, as pressure is applied to the laid marking (e.g, by continuous traffic), the small holes would be resealed by the adhesive.
[0031] The marking systems described herein are easy to apply to substrates that have an exposed surface. Examples of such substrates include, but are not limited to, a vehicular or pedestrian surface (i.e. a parking surface in a vehicle car park or road surface), pathway, corridor, hard standing area, footpath, as well as upright surfaces such as exposed faces of columns or walls. In general, the manufactured markings are taken to a site and laid down in the desired position. Chalk is used to mark around the system to set the position. In some circumstances, it may be desirable to apply a primer to the substrate surface to improve adhesion. In the case when the surface of the substrate is damp or wet, a thin layer of tetrachlorethylene, aromatic hydrocarbon, thermoplastic rubber, hydrocarbon resin or other suitable materials can be applied to the surface of the adhesive during the manufacture of the system. After the system has been applied to the substrate, pressure is applied to the system in order to ensure that the adhesive layer forms a good bond with the substrate surface. The use of rollers and related devices can be used herein. No other special equipment (e.g., torches or other heating devices) is needed to apply the system to the substrate.
[0032] Throughout this application, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the compounds, compositions and methods described herein.
[0033] Various modifications and variations can be made to the compounds, compositions and methods described herein. Other aspects of the compounds, compositions and methods described herein will be apparent from consideration of the specification and practice of the compounds, compositions and methods disclosed herein. It is intended that the specification and examples be considered as exemplary. | Described herein are flexible marking systems possessing one or more painted images. The systems comprise a carrier layer adjacent to the adhesive layer, where the carrier layer is capable of receiving paint to produce painted images. The systems described herein are durable with respect to retaining the painted image. The systems are also durable with respect to remaining on the substrate once applied to the substrate. The systems do not require the use of heat and other expensive equipment for applying the system to the substrate. | 2 |
FIELD OF THE INVENTION
[0001] The invention relates generally to the field of coating a moving web, and in particular to slide bead coating. More specifically, the invention relates to a proximity shield to prevent gas currents from disturbing the coating layers as they are applied using slide bead coating.
BACKGROUND OF THE INVENTION
[0002] Bead coating is well known in the prior art as described, for example, in U.S. Pat. No. 2,761,791. One of ordinary skill in the art uses bead coating to apply multiple layers of liquid to a moving web. In the method typically referred to as slide bead coating, a multilayer composite comprised of superimposed individual coating layers is delivered to the moving web through the use of a coating die. At the end of the coating die, the layers form a continuous liquid bridge or coating bead between the die and the moving web. The slide bead coating method is useful for making thin, highly uniform, composite elements suitable for numerous applications including photographic, thermographic, x-ray, and photoelectric films, among others.
[0003] U.S. Pat. No. 6,579,569 teaches the use of a carrier slide coating method where the viscosity of the lowermost layer or carrier layer is less than 1 cp and the wet thickness of the carrier layer is less than 5 microns. The carrier layer is comprised of a single organic solvent or a blend of organic solvents. Additional coating layers with higher viscosity are applied to the web on top of the carrier layer. This method allows for application of the coatings at high web speeds and with reduced coating artifacts caused by contamination of the slide surface.
[0004] Previous attempts to eliminate the disturbance of flow of photographic coating compositions caused by impact of gas surrounding a slide coating apparatus have not been entirely successful. In some coating rooms, peak gas velocities of 200 feet per minute have been measured. The protective enclosures described in U.S. Pat. No. 4,287,240 have been found to reduce gas flow around the coating station. The enclosures are formed of a foraminous material and are effective in deflecting, diffusing and decelerating ambient forced gas currents. Such forced gas currents are frequently generated by the ventilating and exhausting equipment in the vicinity of the coating apparatus, or by the opening and closing of doors to the coating room, or by movement of personnel in the vicinity of the coating apparatus. The foraminous enclosure is designed to enclose the entire slide coating apparatus and the coating zone, and is not closely spaced to the slide surface of the coating apparatus. Indeed, in U.S. Pat. No. 4,287,240 it is stated that the enclosure should be spaced in the range of about 5 to about 60 cm from the coating composition. Optimum results have been achieved with enclosures formed of a plurality of spaced wall members, each of which is composed of a foraminous material. The best enclosures reduce peak velocities of gas flow to approximately 13 cm/sec. However, even such velocities have been shown to cause disturbances in the coating compositions on the slide which often appear as broad longitudinal streaks in the resulting coating. In most products these streaks are objectionable.
[0005] WO Patent No. 90/01178 describes the use of a close proximity shield to protect liquid flowing down the inclined slide surface from adverse effects of convection gas currents. The temperature of the proximity shield was described to be kept at the same temperature as the coating fluid to prevent condensation of evaporated water. The proximity shield was required to be uniformly spaced 6 to 10 mm from the liquid surface. The proximity shield was described to extend over substantially all the inclined slide surfaces of the coating apparatus. The precise position of the end of the shield was not specified, however it was described to be far enough from the coating backing roller that it allows the coating bead to be viewed by the operators. At least 13 mm spacing would be required for the operator to view the coating bead. The convection gas flow between the solid surface of the coating apparatus and the shield was minimized by closing the space between the shield and the backland area above the uppermost metering slot. Although this shield may work well for the coating composition and thickness described therein, the shield-to-web gap described, therein, is not adequate for carrier slide composition as described in U.S. Pat. No. 6,579,569. Unwanted bands of non-uniform density, or longitudinal streaks, occur when the proximity shield is spaced far enough from the coating backing roller for the operator to view the coating bead.
PROBLEM TO BE SOLVED BY THE INVENTION
[0006] Longitudinal streaks appear as a result of slide bead coating a coating composition that includes higher viscosity layers and a bottom most layer having a viscosity of less than 1 cp. Accordingly, elimination of these streaks and bands is paramount for a high quality coating process.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to overcoming one or more of the problems set forth above. One aspect of the present invention provides a system for preventing gas currents from impacting a coating process for a multi-layer slide coating apparatus, the system includes a multi-layer slide coating apparatus for forming a multilayer composite including a carrier layer and an inclined slide surface; and a web for coating by the multi-layer slide coating apparatus. Additionally, a proximity shield is placed in close proximity to both the web and the inclined slide surface of the multi-layer slide coating apparatus such that gas currents do not disturb the multilayer composite on the inclined slide surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above and other features and advantages of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein identical reference numerals have been used, where possible, to designate identical features that are common to the figures, and wherein:
[0009] FIG. 1 is a schematic of an exemplary multi-slot slide bead coating apparatus including a proximity shield which may be used in the practice of the method of the present invention;
[0010] FIG. 2 shows the proximity shield in profile;
[0011] FIG. 3 is a close-up drawing of different embodiments of the shield lip area; and
[0012] FIG. 4 is a drawing of the edge of the shield and how it integrates with the edge guide.
DETAILED DESCRIPTION OF THE INVENTION
[0013] Referring to FIG. 1 , a schematic shows an exemplary multi-slot slidebead coating apparatus 10 suitable for practicing the method of the present invention. The multi-slot slide bead coating apparatus 10 is typically used to deliver and coat multiple coating compositions simultaneously as a stacked composite of layers. Multi-slot slide bead coating apparatus 10 is shown as having only four slots but multiple slot coating apparatuses may have fewer than four slots and are also known to deliver a composite layer comprised of five or six (or even more) coating composition layers.
[0014] Multi-slot slide bead coating apparatus 10 , shown in a side elevation cross-section in FIG. 1 , includes a front section 15 , a second section 20 , a third section 25 , a fourth section 30 , and a back plate 35 . There is an inlet 40 into second section 20 for supplying coating liquid to first metering slot 45 via pump 50 to thereby form a lowermost layer or carrier layer 55 . There is an inlet 60 into third section 25 for supplying coating liquid to second metering slot 65 via pump 70 to form layer 75 . There is an inlet 80 into fourth section 30 for supplying coating liquid to third metering slot 85 via pump 90 to form layer 95 . There is an inlet 100 into back plate 35 for supplying coating liquid to fourth metering slot 105 via pump 110 to form layer 115 . Each metering slot 45 , 65 , 85 , and 105 includes a transverse distribution cavity. Front section 15 includes a first inclined slide surface 120 , and a coating lip 125 . There is a second inclined slide surface 130 at the top of second section 20 . There is a third inclined slide surface 135 at the top of third section 25 . There is a fourth inclined slide surface 140 at the top of fourth section 30 . Back plate 35 extends above the fourth inclined slide surface 140 to form a back land surface 145 .
[0015] Residing adjacent to the multi-slot slide bead coating apparatus 10 is a coating backing roller 150 about which a web 155 is conveyed. Typically, the multi-slot slide bead coating apparatus 10 is movable from a non-coating position toward the coating backing roller 150 and into a coating position.
[0016] Still referring to FIG. 1 , the method of the present invention has a proximity shield 160 (also shown in greater detail in FIG. 2 ) placed a certain distance from the first inclined slide surface 120 , forming a shield-to-slide surface gap 165 between the proximity shield 160 and the first inclined slide surface 120 . The shield-to-slide surface gap 165 is defined as the closest distance between the proximity shield 160 and the first inclined slide surface 120 . The proximity shield is positioned to be substantially parallel to the first inclined slide surface 120 . The proximity shield 160 is also placed or designed in such a manner that there are shield-to-liquid gaps 170 , 175 , 180 , and 185 between the proximity shield 160 and the liquid layer 115 . The proximity shield 160 is positioned so that there is a specific shield-to-web gap 190 between the shield lip 195 and the web 155 . A seal 200 is made between the shield back 205 and the back land surface 145 . The shield-to-slide surface gap 165 can range from 4 mm to 13 mm. The more preferred range is 5 mm to 8 mm, with the most preferred value equal to 6 mm.
[0017] FIGS. 2 & 3 show the proximity shield in more detail. FIG. 2 shows a shield lip 195 and a front face 210 . Different embodiments of the shield lip 195 and front face 210 are shown in FIG. 3 . The shield lip 195 can be a sharp point as shown in configuration 3 A. The shield lip 195 can also be rounded as shown in configuration 3 B. The radius of curvature of the shield lip 195 can range from 1 micron to 10 mm. In the extreme, the radius can be infinite corresponding to the flat surface shown in configuration 3 C. In this embodiment, there is no shield lip 195 , only a front face 210 . In configurations 3 A and 3 B, the front face 210 is cut away forming an angle 215 so that the shield lip 195 is the closest point to the moving web 155 . This angle 215 can be between 10 and 80 degrees. For the exemplary embodiment shown in FIG. 2 , the angle is 56 degrees. The shield-to-web gap 190 is defined as the closest distance between the proximity shield 160 and the web 155 . For configurations 3 A and 3 B the closest point of the proximity shield 160 would typically be the shield lip 195 . For configuration 3 C, this would depend on location of the coating lip 125 in relation to the coating backing roller 150 , as well as the angle of the first inclined slide surface 120 .
[0018] Configuration 3 D is an alternative embodiment where the front face 210 is curved to match the curvature of the coating backing roller 150 . In this case the entire front face 210 is substantially the same distance from the web 155 . There is no shield lip 195 to define for configuration 3 D.
[0019] FIG. 2 demonstrates a step cutback angle 265 . For example, the proximity shield 160 may be angularly cut from 0-65°. This portion of the proximity shield 160 is cut back in order to maintain the shield-to-liquid gaps 175 , 180 , and 185 . If the combination of total coating layer thickness and any difference in height between the inclined slide surfaces 120 , 130 , 135 , 140 (not shown in FIG. 1 ) would cause the coating liquid to close the shield-to-liquid gaps 175 , 180 , 185 , then the proximity shield 160 can be cut back to avoid this. For some fluid and coating apparatuses, it may not be necessary to have a step cutback angle 265 .
[0020] FIG. 4 shows a nexus between the proximity shield 160 and an edge guide 220 . The edge guide 220 contains the fluid on the inclined slide surfaces 120 , 130 , 135 , and 140 (shown in FIG. 1 ) and defines the coating width (not shown). An edge guide holder 225 is used to hold the edge guide 220 to the inclined slide surfaces 120 , 130 , 135 , and 140 . A pin 230 is attached to the edge guide holder 225 . The edge guide 220 has an overhang portion 235 which extends over the coating layer 115 . The proximity shield 160 has a cut out area 240 which mates with the overhang portion 235 of the edge guide 220 . This mating forms an effective seal to prevent gas from leaking into or out of a gas space 245 located under the proximity shield 160 . The proximity shield 160 also has a bracket 250 , which has a hole (not shown) that fits over the pin 230 . The connection between the bracket 250 and the proximity shield 160 is adjustable so that the pin 230 maintains the desired shield-to-web gap 190 .
[0021] The gas contained within the gas space 245 may be air. It may also be an inert gas such as Nitrogen or Carbon Dioxide. The inert gas could also have added solvent vapors to retard drying of the coating fluids on the edge guide 220 or the back land surface 145 .
[0022] In addition to the embodiment shown in FIG. 4 , alternate arrangements for positioning the shield are possible. The pin 230 could be replaced with a notch or hook or screw. Instead of a pin 230 , the edge guide 220 could have a ledge on which the bracket 250 rests. Other arrangements are envisions that set both the shield-to-slide surface gap 165 and the shield-to-web gap 190 . The proximity shield 160 could also not include a cut out area 240 , in which case the proximity shield 160 would sit directly on top of the overhang portion 235 .
[0023] In one embodiment of the present invention, the lowermost or carrier layer 55 (shown in FIG. 1 ) is an organic solvent or blend of organic solvents that is substantially free of other constituents. The term “substantially free of other constituents” as used herein is intended to mean that the organic solvent or blend of organic solvents have a purity level of at least about 98% and that any contaminants or additives present do not affect the viscosity of the carrier layer 55 . Examples of suitable organic solvents include methanol, acetone, methylethyl ketone, methyl isobutyl ketone, methylene chloride, toluene, methyl acetate, ethyl acetate, isopropyl acetate, and n-propyl acetate. In another embodiment, the carrier layer 55 may also be a diluted version of the upper liquid layer 75 . The carrier layer 55 may also contain other addendum such as polymers or dyes as long as they do not significantly affect the viscosity of the carrier layer 55 .
[0024] The second liquid layer 75 which is metered through a second metering slot 65 , moves down the second inclined slide surface 130 , and is accelerated by the carrier layer 55 down the first inclined slide surface 120 to the coating bead 255 . The second liquid layer 75 should preferably be totally miscible with lowermost layer 55 and is therefore preferably organic, but may also contain water. As layers 95 and 115 in FIG. 1 are shown, additional upper layers may also be applied using the multi-slot slide bead coating apparatus 10 . These additional upper layers may be of a distinct composition relative to the second liquid layer 75 or of the same composition. Similarly, the number of upper layers may also be further increased by extension of the number of metering slots (not explicitly shown in FIG. 1 ).
[0025] Because the method of the present invention may involve application of highly volatile organic solvents, the temperature at which coating is performed is preferably less than or equal to 25° C. to avoid non-uniformities due to streaks and mottle. Methylene chloride, acetone, methyl acetate and methanol are examples of highly volatile organic solvents having a vapor pressure above 100 mm Hg at 25° C. The proximity shield 160 is typically maintained at the same temperature as coating fluids in order to avoid thermal gradients within the gas space 245 .
[0026] The carrier slide coating method, as described in U.S. Pat. No. 6,579,569, is extremely sensitive to stray gas currents as well as gas currents induced by the coating method itself. This is especially true when the coating layers are very thin (<5 microns for the carrier layer 55 and <10 microns for the sum of the subsequent layers 75 , 95 , and 115 ). Conventional slide coating typically uses layers that are much greater in thickness. This sensitive nature of the coating layers results in very precise requirements for the placement of a proximity shield 160 . Conventional methods teach that the shield-to-web gap 190 can be large enough that an operator can view the coating bead 255 . For carrier slide coating with coating construction described herein, if the shield-to-web gap 190 were allowed to be this large, the subsequent coating quality would be very poor. This is because the coating bead 255 would be disturbed by gas currents and longitudinal streaks would occur.
[0027] When the coating solutions contain volatile organic solvents, the drying at the static contact lines can be substantial. In order to prevent this drying, a clam shell must be created wherein the shield edges 260 and the shield back 205 are sealed. This clamshell can be either passive or solvent laden gas can be supplied. If the proximity shield 160 is sealed at the shield edges 260 outside the edge guides 220 , there will be a greater region of atmosphere requiring saturation as well as the risk of stray gas currents occurring at the edges. In order to prevent these problems, the proximity shield 160 is integrated with the edge guide 220 as shown in the FIG. 4 . This integration effectively creates the enclosure. Referring to FIG. 4 , the overhang portion 235 of the edge guide 220 serves as a means for creating a seal, as a means for holding the proximity shield 160 in place; as a means for setting the shield-to-slide surface gap 165 , as a means for maintaining a parallelism between the proximity shield 160 and the first inclined slide surface 120 ; and as a means for creating a partially saturated environment at the edges when the proximity shield 160 is not yet in place.
[0028] The proximity shield 160 can be sealed in the back in a number of ways. A gasket material, such as rubber, can be used to create a seal 200 . Alternatively, the proximity shield 160 can rest on the back land surface 145 of the multi-slot slide bead coating apparatus 10 . The proximity shield 160 can either be placed directly on the edge guides 220 and seal 200 or else a movable and/or hinged design could be envisioned. Another embodiment is to have no back seal 200 where there is an opening between the shield back 205 and the back land surface 145 .
[0029] When the proximity shield 160 is completely sealed, the only place for gas exchange between the outside and the gas space 245 under the proximity shield 160 is through the shield-to-web gap 190 . The placement of the proximity shield 160 relative to the web 155 , i.e. the shield-to-web gap 190 , was found to be instrumental to forming a coating without objectionable defects, such as longitudinal streaks.
[0030] The proximity shield 160 can be constructed from a variety of materials, such as plastic, glass, metal, metal alloys, wood, or paper. The proximity shield 160 can also be made from a combination of these materials. Example plastic materials are polyethylene, Teflon, and polycarbonate. The proximity shield 160 can be made from a transparent material in order to enable the operator to see the fluid underneath. A transparent plastic material, such as polycarbonate, could be coated with a protective layer. Some of the purposes for this protective layer are to provide static dissipation properties and to protect the material from attack by the organic solvents. Hence, a semi-transparent metal may coat the transparent plastic.
COMPARATIVE EXAMPLE 1
[0031] The multi-slot slide bead coating apparatus 10 illustrated in FIG. 1 was used to apply two organic layers to a moving web 155 of untreated polyethylene terephthalate (PET). The carrier layer 55 consisted of a mixture of solvents, having a viscosity of 0.9 cp and a wet thickness of 3.23 μm on the web 155 . The second layer was a mixture of polymer, dye and organic solvents. The second layer was delivered through the second, third and fourth metering slots 65 , 85 , 105 , respectively, and had a viscosity of 750 cp and a combined final wet thickness of 3.49 μm on the web 155 . Coatings were applied at a temperature of 23.9° C. The gap between the coating lip 125 and the moving web 155 was 200 μm. The pressure differential across the coating bead 255 was 1.8 cm H 2 O. The web speed was 190 m/min.
[0032] When the proximity shield 160 was used, the shield-to-slide surface gap 165 was set to 6 mm and the shield-to-web gap 190 was set to 3.18 mm. Table A demonstrates the effectiveness of the proximity shield 160 for preventing density bands (or longitudinal streaks).
TABLE A Proximity Shield 160 Resulting Coating Quality Off Severe wide variable bands On No bands or streaks
COMPARATIVE EXAMPLE 2
[0033] The same coating compositions were used as described in comparative example 1. In this case the shield-to-web gap 190 was varied according to Table B. There is an optimum value for the shield-to-web gap 190 . When the distance is too small, short narrow wavy bands occur. When the distance is too large, severe bands occur similar to that seen when there is no proximity shield 160 in place. The shield-to-web gap 190 that would allow the operator to see the coating bead 255 is the last value in Table B, 13 mm. At this distance, the bands are severe. The available range for shield-to-web gap 190 is between 2.5 and 4.5 mm. The most preferred shield-to-web gap 190 is 3.18 mm.
TABLE B Shield-to-Web Gap 90 (mm) Resulting Coating Quality 1.27 Short narrow wavy bands 1.91 Narrow bands or streaks 2.54 Narrow streaks that move 3.18 No bands or streaks 4.45 Wide variable bands 6.35 Severe wide variable bands 13.0 Severe wide variable bands
[0034] The invention has been described with reference to one or more embodiments. However, it will be appreciated that a person of ordinary skill in the art can effect variations and modifications without departing from the scope of the invention.
PARTS LIST
[0000]
10 Multi-slot slide bead coating apparatus
15 Front section
20 Second section
25 Third section
30 Fourth section
35 Back plate
40 Inlet
45 First metering slot
50 Pump
55 Carrier layer
60 Inlet
65 Second metering slot
70 Pump
75 Layer
80 Inlet
85 Third metering slot
90 Pump
95 Layer
100 Inlet
105 Fourth metering slot
110 Pump
115 Layer
120 First inclined slide surface
125 Coating lip
130 Second inclined slide surface
135 Third inclined slide surface
140 Fourth inclined slide surface
145 Back land surface
150 Coating backing roller
155 web
160 Proximity shield
165 Shield-to-slide surface gap
170 Shield-to-liquid gap
175 Shield-to-liquid gap
180 Shield-to-liquid gap
185 Shield-to-liquid gap
190 Shield-to-web gap
195 Shield lip
200 Seal
205 Shield back
210 front face
215 Angle
220 Edge guide
225 Edge guide holder
230 Pin
235 Overhang portion
240 Cut out area
245 Gas space
250 Bracket
255 Coating bead
260 Shield edge
265 Step cutback angle | A system prevents gas currents from impacting a coating process for a multi-slot slide bead coating apparatus. The system includes a multi-layer slide coating apparatus for forming a multilayer composite including a carrier layer and a slide surface; and a web for coating by the multi-slot slide bead coating apparatus. Additionally, a proximity shield is placed in close proximity to both the web and the slide surface of the multi-slot slide bead coating apparatus such that gas currents do not disturb the multilayer composite on the slide surface. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to rotating electrical machines and more particularly to synchronous machines such as alternators for motor vehicles, traction engines or other machines.
Among the known machines, mention may be made of machines with excitation by windings mounted in the rotor, machines with excitation by magnets mounted in the rotor and machines with double excitation by both windings and magnets mounted in the rotor.
Such machines are especially described in Patent Application FR 97/03429 filed on Mar. 20, 1997 by the Applicant.
Although giving acceptable results, the known double-excitation machines are relatively bulky because of the presence of brushes and slip rings.
SUMMARY OF THE INVENTION
The invention therefore aims to create a rotating electrical machine of the double-excitation type which, whilst still having good performance characteristics, is less bulky than the known machines of the same type.
The subject of the invention is therefore a rotating electrical machine comprising, mounted on a shaft, a rotor whose magnetic circuit carries at least one excitation element and a stator whose magnetic circuit carries a stator winding, characterized in that the at least one said excitation element of the rotor comprises at least one annular magnet associated with at least two discs each provided with radial teeth uniformly distributed around their periphery and at least one annular piece provided with slots in each of which a tooth of at least one toothed disc is engaged without any contact, and in that the magnetic circuit of the stator includes an even number, at least equal to two, of annular magnetic-circuit elements, at least one stator excitation winding being arranged between at least two adjacent elements among the said magnetic-circuit elements.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more clearly understood with the aid of the description which follows, given solely by way of example and with reference to the appended drawings, in which:
FIG. 1 is a cross-sectional partial schematic view of an elementary double-excitation rotating electrical machine according to the invention;
FIG. 2 is a cross-sectional partial schematic view of a variant of the elementary machine in FIG. 1;
FIG. 3 is a cross-sectional partial schematic view of complete double-excitation electrical machine produced frog the elementary machine in FIG. 1;
FIG. 4 is a cross-sectional partial view of a double-excitation electrical machine resulting from the juxtaposition of several elementary machines of FIG. 1;
FIG. 5 is a cross-sectional partial schematic view of a double-excitation machine of a particular type;
FIG. 6 is a cross section on the line 6 — 6 of the machine in FIG. 5 without its stator;
FIG. 7 is a cross-sectional partial view of a double-excitation machine with an offset stator excitation winding in the rotor; and
FIG. 8 is a cross-sectional partial schematic view of a double-excitation electrical machine according to the invention resulting from the juxtaposition of a machine of FIG. 7 and of machines similar to that of FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The electrical machine shown in FIG. 1 is a machine comprising, mounted on a shaft 1 made of non-magnetic material, a rotor 2 whose magnetic circuit includes toothed discs 3 provided with radial teeth 4 uniformly distributed around their periphery.
The radial teeth 4 of one plate 3 are offset with respect to the radial teeth of the other plate so that a tooth of one plate lies opposite a gap between the teeth of the other plate.
An annular piece 5 provided with slots 6 uniformly spaced around its periphery, which in the present example are made in the form of axial slots emerging at the opposite ends of the annular piece, is mounted coaxially with respect to the shaft 1 . The teeth 4 of the toothed discs 3 are engaged in corresponding slots 6 in the annular piece 5 without any contact with the walls of the said slots. The annular piece 5 is fastened to the shaft 1 by any suitable mechanical means (not shown).
Placed between the toothed discs 3 is an annular excitation magnet 7 .
Moreover, in the example shown in FIG. 1, magnets 8 are placed in the gaps between the teeth 4 of the toothed discs 3 and the walls of the corresponding slots 6 of the annular piece 5 .
However, the gaps between the teeth 4 may also be devoid of such magnets.
The rotor 2 is surrounded by a stator 10 comprising a laminated magnetic circuit formed from two magnetic-circuit elements 11 joined together by an external annular yoke 12 and on which an armature winding 13 is mounted. An excitation winding 14 is placed between the magnetic-circuit elements 11 .
The electrical machine shown in FIG. 2 is in every way similar to that of FIG. 1 apart from the fact that it has a shaft 15 made of a magnetic material and from the fact that the toothed discs 3 each have a central bore 16 ensuring that they are magnetically separated from the shaft 15 .
Advantageously, a ring of insulating material 17 is placed in each central bore 16 .
Furthermore, in the present embodiment, the gaps between the teeth 4 of the toothed discs 3 and the walls of the slots 6 of the annular piece 5 are devoid of magnets.
The electrical machine shown in FIG. 3 has a shaft 21 made of non-magnetic material carrying a rotor 22 which includes two end plates 23 between which two toothed discs 24 are placed, the said toothed discs 24 being provided with radial teeth 25 placed at regular angular intervals, the teeth of one of the discs being angularly offset with respect to the teeth of the other disc.
Mounted on the end plates 23 is an annular piece 26 provided with slots 27 which, in the present example, are axial slots and in which the teeth 25 of the toothed discs 24 are engaged without any contact.
Excitation magnets 28 , 29 are placed, on the one hand, between the toothed discs 24 and, on the other hand, between each toothed disc and the corresponding end plate 23 .
The excitation magnet 28 placed between the toothed discs 24 and the excitation magnets 29 placed between each toothed disc and its corresponding end plate 23 are of reverse polarities.
The rotor thus formed is surrounded by a stator 30 comprising a magnetic circuit formed from two magnetic-circuit elements 31 each placed opposite a corresponding toothed disc 24 and on which a stator winding 32 is mounted.
The magnetic-circuit elements 31 are joined together by a yoke 33 . Placed between the magnetic-circuit elements 31 is an excitation winding 34 .
The electrical machine shown in FIG. 4 results from the juxtaposition of several elementary machines such as that shown in FIG. 1 .
It has a common shaft 41 made of non-magnetic material which carries a rotor 42 formed from two end plates 43 and of toothed discs 44 a to 44 n , n being an even number at least equal to two.
Each of the toothed discs 44 a to 44 n has teeth 45 a to 45 n offset one with respect to another.
The end plates 43 and the toothed discs 44 a to 44 n have bores 46 and 47 a to 47 n through which the non-magnetic shaft 41 passes. An advantageous embodiment consists in producing this annular piece by assembling n coaxial elementary annular pieces. Mounted on the end plates 43 is an annular piece 48 perforated by slots 49 a to 49 n uniformly distributed around its periphery and offset one with respect to another. The teeth 45 a to 45 n of the toothed discs 44 a to 44 n are engaged in the corresponding slots 49 a to 49 n without any contact with the latter.
Placed in the gaps provided between the end plates 43 and the toothed discs 44 a to 44 n , defining with the shaft 41 and the perforated piece 48 forming a sleeve joined to the end plates, on the one hand, two end chambers 51 located between the first end plate 43 and the adjacent toothed disc 44 a and between the second end plate 43 and the adjacent toothed disc 44 n and, on the other hand, chambers 52 a to 52 n− 1 located between the toothed discs 44 a to 44 n , are annular magnets 53 and 54 a to 54 n− 1, respectively.
The arrangement of these annular magnets is such that the polarities of the two adjacent magnets are of opposite sign or polarity.
The excitation magnets 53 located in the end chambers 51 have a thickness equal to half that of the magnets 54 a to 54 n− 1 located in the chambers 52 a to 52 n− 1 defined between the successive toothed discs 44 a to 44 n.
The rotor that has just been described is mounted in a stator 55 having as many magnetic-circuit elements 55 a to 55 n as the rotor has toothed discs 44 a to 44 n . A common armature stator winding 56 is mounted on these magnetic-circuit elements.
Spaced between two successive adjacent magnetic-circuit elements is a corresponding excitation winding 57 a to 57 n− 1.
The electrical machine shown in FIG. 5 has a shaft 60 made of magnetic material on which is mounted a rotor 61 comprising two toothed discs 62 whose radial teeth 63 are uniformly distributed around the periphery of each disc, the teeth of one of the discs being offset with respect to those of the other.
The shaft 60 furthermore carries an annular piece 64 provided with slots such as the slot 65 which, in the present embodiment, consist of axial slots and in which the teeth 63 of the toothed discs 62 are engaged without any contact.
The annular piece 64 is linked to the shaft 61 by a disc-shaped central core 66 .
The toothed discs 62 each have, surrounding the shaft 60 , a bore 68 in which annular magnets 69 are placed.
Magnets 70 are also placed between the core 66 and each of the toothed discs 62 , while, as shown in FIG. 6, the gaps between the teeth 63 of each of the toothed discs 62 and the walls of the slots 65 in the annular piece 64 are furnished with magnets 72 .
The gaps between the teeth 63 of the toothed pieces 62 and the walls of the notches 65 in each annular piece 64 may also be devoid of such magnets.
The rotor that has just been described is surrounded by a stator 74 which has a magnetic circuit formed from two laminated annular magnetic-circuit elements 75 joined together by an external yoke 76 and carrying an armature winding 77 .
An excitation winding 78 is furthermore provided between the magnetic-circuit elements 75 .
The machine shown in FIG. 7 has a non-magnetic shaft 81 which carries a rotor 82 formed from a toothed double disc 83 mounted on the shaft 81 and provided with radial teeth 84 a , 84 b made on each of the elements 83 a , 83 b of the toothed double disc which thus define two toothed discs. The teeth 84 b are angularly offset with respect to the teeth 84 a.
Mounted on either side of the toothed double disc 83 are end plates 85 provided with teeth which between them define axial slots 86 in which the radial teeth 84 a and 84 b of the toothed double disc 83 are engaged without any contact.
The end plates 85 provided with axial teeth defining annular pieces similar to those of the embodiments described previously.
Placed between the end plates 85 and the opposite ends of the toothed double disc 83 are annular excitation magnets 87 .
Furthermore, magnets 88 are placed in the spaces left free between the teeth 86 of the end plates 85 and the teeth 84 a , 84 b of the toothed double disc 83 .
The magnets 88 may also be omitted.
The rotor thus formed is surrounded by a stator 90 comprising a magnetic circuit formed from two laminated magnetic-circuit elements 91 each placed opposite one of the elements 83 a , 83 b of the toothed double disc 83 and joined together on the outside by a yoke 92 .
An excitation winding 93 is placed between the two magnetic-circuit elements 91 .
Made in the toothed double disc 83 of the rotor 82 is a groove 94 in which a second stator excitation winding 95 is placed.
According to a variant, the machine shown in FIG. 7 may have only one excitation winding such as the winding 93 located between the magnetic-circuit elements 91 of the stator, or else a single excitation winding such as the winding 95 placed in the annular groove 94 of the toothed double disc 83 .
The electrical machine shown in FIG. 8 results from the juxtaposition of a double-excitation electrical machine of the type shown in FIG. 7 and of an elementary machine such as that described with reference to FIG. 3 .
It has a shaft 101 made of non-magnetic material which carries a rotor 102 comprising end plates 103 provided with teeth defining, between them, axial slots 104 which are uniformly distributed around their periphery and facing each other in order to form two perforated annular pieces or cages.
Placed between the end plates 103 made of magnetic material are intermediate toothed discs formed by a central toothed double disc 105 , an element 105 a of which has radial teeth 106 a and a second element 105 b of which has radial teeth 106 b . The teeth 106 a , 106 b of the first and second elements 105 a , 105 b of the toothed double disc 105 are uniformly distributed around the periphery of the double disc and angularly offset one with respect to another.
On either side of the toothed double disc 105 , the elements 105 a , 105 b of which form intermediate toothed discs, the rotor 102 has a first toothed disc 107 provided with radial teeth 108 and a second toothed disc 109 provided with radial teeth 110 . The teeth 108 and 110 of the toothed discs 107 and 109 are uniformly distributed around the periphery of the corresponding discs and angularly offset.
Engaged respectively in the axial slots 104 of the end plates 103 are the teeth 106 a of one of the elements 105 a of the toothed double disc 105 and the teeth 108 of the adjacent first toothed disc 107 , on the one hand, and the teeth 106 b of the other element 105 b of the toothed double disc 105 and the second teeth 110 of the corresponding toothed disc 109 , on the other hand.
Magnets 115 are placed in the spaces left free between the teeth 106 a and 106 b of the elements 105 a and 105 b of the toothed double disc and the slots 104 of the end plates 103 .
Annular excitation magnets 112 , 114 are inserted, on the one hand, between the end plates 103 and the first and second toothed discs 107 , 109 and, on the other hand, between the latter and the toothed double disc 105 .
The rotor thus formed is surrounded by a stator 116 comprising a magnetic circuit formed from four magnetic-circuit elements 116 a , 116 b , 116 c , 116 d and on which an armature stator winding 117 is mounted. Each of the annular circuit elements 116 a to 116 d is placed opposite the radial teeth of a toothed disc 107 , 109 and opposite each of the elements 105 a , 105 b of the toothed double disc 105 .
The magnetic-circuit elements 116 b , 116 c which are placed opposite the two elements 105 a , 105 b of the toothed double disc 105 are joined together by an external yoke 118 . A stator excitation winding 119 is placed between the elements of the magnetic circuit 116 b and 116 c.
Moreover, another stator winding 120 is placed in an annular slot 121 made in the magnetic circuit of the rotor between the two elements 105 a , 105 b of the toothed double disc 105 .
Because of the arrangement of this stator excitation winding inside a groove made in the body of the rotor, the machine described with reference to FIG. 8 is less bulky than that of known double-excitation machines. What is more together with the machine in FIG. 7, it is the least bulky of the machines according to the invention. | A double excitation, rotating electrical machine mounted on a shaft includes a rotor whereof the magnetic circuit carries at least one excitation element and a stator whereof the magnetic circuit carries a stator coil. The at least one excitation element includes at least a ring-shaped magnet associated with at least two disks each provided with radial teeth evenly distributed at their periphery and at least a ring-shaped part provided with slots in each of which is engaged contactless, one tooth of at least one toothed disk, and the stator magnetic circuit includes an even number, not less than two, of ring-shaped elements of magnetic circuit, at least an excitation stator coil being arranged between at least two neighboring elements among the magnetic circuit elements. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a power-loom harness fitted with an upper and lower, sectionally contoured, rail, for instance a bar rail, hereafter called "rail", the heddles being held to the rails by means of eyes in their ends.
2. Description of the Related Art
Several harnesses of the initially cited kind form a so-called harness system. The individual harnesses of this system are alternately raised and lowered by means of a harness machine in accordance with predetermined patterns in order that sheds shall be formed from warp yarns guided by the heddles, a filling yarn being transported into the sheds. Conventionally the heddle eyes and the rails are so structured that, for one direction of motion of the harness, one of the rails rests by a drive surface against a mating heddle eye and drives these heddles. As regards the other direction of motion, the other rail by means of a drive surface drives a mating surface of the heddle eyes associated with it. Because the heddles and also the harness expand thermally and both are subject to certain manufacturing tolerances, and because the heddles must furthermore be displaceable along the rails, for instance to allow insertion or repair of the warps, the heddles are provided with a play of on the order of 2 to 3 mm between the drive surface of one rail and the drive surface of the other rail.
When the harness is in the raised position, the heddles, that is their eyes, make contact with the drive surface of the upper rail. If thereupon the harness is lowered, the heddles disengage, due to tension in the warps and inertia, at a given time, from the drive surface of the upper rail and thereafter make contact with the drive surface of the lower rail. Similarly, the heddles disengage, at a given time during the upward motion of the harness, from the drive surface of the lower rail and thereafter make contact with the drive surface of the upper rail. The disengagement of the heddles from one rail and their subsequent application against the other rail following a free displacement in the direction of motion of the harness over a path of 2-3 mm causes impacts which entail noise on one hand and heddle vibration on the other hand. Especially at high speeds and in the long term, these impacts and the vibrations so incurred may cause rupture of the heddles and/or of the harnesses.
It is known from the German patent document U 94 13 705.6 to use only one rail as the drive rail to drive the heddles both during the raising and the lowering of the harness, so that the play may be reduced and the magnitude of the impacts may be lessened. In the known design, the rail acting as the drive rail is accordingly fitted with a thin, transverse leg that enters, with little play, a drive slot of the associated eye of the heddles.
SUMMARY OF THE INVENTION
The objective of the present invention is to improve a harness of the type including bar rails to hold heddles by means of eyes situated at ends of the heddles so that the magnitude of the impacts occurring during weaving shall be reduced.
This problem is solved by associating one or more insets with one of the rails and filling the gap between the drive surfaces of this rail as seen in the direction of motion on one hand and on the other hand the mating surfaces of the heddle eyes in the direction of motion of the harness to such an extent that the play shall be less than between the other rail and the heddle eyes pertaining to this latter rail.
The play in the harness' direction of motion between one of the rails and the associated eyes is reduced so much by means of the one or more insets that the one of the rails drives the heddles both during the raising and lowering of the harnesses, that is, the rail acts as a drive rail similarly to the case of the German patent document 94 13 705.6, while the other rail merely guides the heddles. As a result, play can be substantially reduced, for instance to less than 1 mm, and the magnitudes of the generated impacts substantially decreased.
In a further embodiment of the invention, the one or more insets are made of plastic. Thereby the generated noise may be reduced further, the inset or insets also providing damping in at least one of the directions of displacement of the harness.
In a first embodiment of the invention, the insets are mounted to the heddles. Illustratively these insets may be inserted in straddling manner in the heddle eyes.
In another embodiment of the invention, at least one strip-shaped inset is provided which runs essentially over the full length of the associated rail. Such a strip-inset is easy to assemble. Illustratively, after mounting the heddles, the one strip-shaped inset may be slipped into the heddle eyes.
In a further embodiment, the inset is a tubular element which can be expanded by a controlled supply of a pressurized medium. Due to the supply of the pressurized medium, the tubular element can be expanded to such an extent that the play between the heddles and the driving rail is in practice eliminated. If, however, the pressurized medium is exhausted from this tubular element, the element will contract so much that the heddles can easily be shifted on the rail.
Further features and advantages of the invention are elucidated in the following description of the illustrative embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevation of a harness of the invention,
FIGS. 2, 3 are partial sections along the line II--II of FIG. 1 for different drive positions of the harness,
FIGS. 4-13 are sections of further illustrative embodiments similar to those along line II--II of FIG. 1, shown in pairs,
FIGS. 14, 15 are sections similar to those of FIGS. 2 and 3 of an illustrative embodiment of the invention including an inset expandable by a pressurized medium, and
FIG. 16 is an elevation of a harness corresponding to the illustrative embodiment of FIGS. 14 and 15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The harness 1 shown schematically in FIG. 1 includes two side struts 2, 3 connected by cross-braces 4 and 5. A rail 6, 7 is affixed by fasteners 8 and screws 9 (also see FIGS. 10, 11) at predetermined spacings at each cross-brace 4, 5. Heddles 10 are mounted between the rails 6 and 7. Detachable collar elements 11 are present at the side edges of the rails 6 and 7 and prevent the heddles from slipping off the rails 6, 7. The heddles 10 include thread-eyes 12 to guide the warps (not shown).
As shown in FIGS. 2 and 3, the heddles 10, which are made of stamped sheetmetal, include eyes 13, 14 in the area of their two ends, each eye enclosing one rail 6, 7. In this embodiment the sizes of the eyes 13, 14 are equal. However, as elucidated below, the design is such that only the upper rail 6 drives the heddles 10 when the harness 1 moves up or down in the direction of arrow A, namely in the longitudinal direction of the heddles 10.
The upper rail 6 includes an upper drive surface 15 associated with a mating surface of the eyes 13 of the heddles 10. The rail 6 furthermore includes a lower drive surface 16 which is also associated with a mating surface of the eyes 13 of the heddles 10. A strip-shaped inset 35 is mounted between the lower drive surface 16 and its associated mating surface of the eyes 13 of the heddles 10 and determines the play by which the heddles 10 may shift relative to the upper rail 6 during the up and down motions of the harness. The strip inset 35 runs over substantially the full length of the rail 6 and preferably is made of plastic, for instance a polyamide. The strip inset 35 limits the possible play to 1 mm or less. Because a lateral play also is present in the eyes 13 relative to the rail 6 and further relative to the strip inset 35, the heddles 10 are very easily shifted on the rail 6. A play is present between the top sides and the bottom sides of the lower rail 7 and the eye 14, and this latter play is substantially larger than that between the upper rail 6 and the strip 35 relative to the eyes 13. Preferably the play between the rail 7 and the eye 14 in the direction of the harness-motion A (the longitudinal direction of the heddles 10), is at least twice the play in the zone of the upper rail 6, which may not only be less than 1 mm, but also may be on the order of 0.5 mm or even less.
In its position shown in FIG. 2, the drive surface 15 makes contact with the associated mating surface of the eyes 13 of the heddles 10. The play occurs between the lower drive surface 16 of the rail 6 and the strip 35 which is inserted only loosely, that is, it is affixed neither to the heddles 10 nor to the rail 6. In the position shown in FIG. 3, it is the lower drive surface 16 of the rail 6 which makes contact with the strip inset 35 which in turn makes contact with the mating surface of the eye 13 of the heddle 10. In this position the play arises between the upper drive surface 15 and the associated mating surface of the eye 13.
In a variation of this embodiment, the strip inset is inserted between the rail 7 and the eyes 14 of the heddles 10 so that the rail acts as the drive element driving the heddles 10 in the direction of motion A while the contour rail 6 only guides the heddles 10.
In another variation similar to the embodiment of FIGS. 2 and 3, shown in FIGS. 10 and 11, the heddles 10 include open eyes 18, 19. In this variation, insets 35, 35' are inserted between the upper drive surface 15 of the rail 6 and the lower drive surface 16 of the rail 6 on the one hand and the mating surfaces of eyes 18 on the other hand. The strip insets 35, 35' also are loosely inserted in the embodiments of FIGS. 10 and 11. However in another variation, the strip insets 35 or 35' are affixed to the rail, for instance by adhesive. Obviously, the embodiment variation of FIGS. 10 and 11 may also be modified in such a manner that the strip insets 35 and 35' are associated with the rail 7, which then acts as a drive element driving the heddles 10 during the up-and-down motion of the harness 1, the rail 6 in this case acting only as a guide.
In the embodiment shown in FIGS. 4 and 5, the heddles 10 are fitted with hooked, open eyes 22, 23 each including a bend pointing transversely to the harness' direction of motion A and entering channel-like recesses 24, 25 of the cross-sectionally contoured rails 6, 7. In this embodiment the lower rail 7 is a heddle drive-element and includes an effective drive surface 30 during its lifting motion and an effective drive surface 29 during its lowering motion, the effective drive surfaces being associated with mating surfaces of the bend of the eye 23 that enters the recess 24. A preferably plastic inset 28 is present between the drive surface 30 and the mating surface of the hooked eye 23 to limit the play in the direction A and by which play the heddles 10 can move relative to the rail 7. Individual insets 28 may be provided that are affixed to the heddles 10. Preferably however a strip inset 28 is used that runs at least approximately over the full length of the rail 7 and that is loosely inserted. The structures of the two rails 6, 7 are the same and they are mounted in mirror-symmetrical manner. Because the bend entering the recess 25 is without function in this embodiment, this bend also may be omitted in the region of this eye 22.
The embodiment of FIGS. 6 and 7 is basically that of FIGS. 4 and 5, but now the upper rail 6 is the drive element and the lower rail 7 merely serves as a guide. The eye 31 associated with the lower rail 7 therefore may be simplified, that is, the bend entering the recess of the lower rail 7 can be eliminated. In this case the recess 25 of the rail 6 constitutes two drive surfaces 26, 27 associated with the bend entering the recess 25 of the hooked eye 22. A substantially strip-shaped inset 32 is inserted into the recess 25 and runs substantially over the full length of the rail 6. This strip inset 32 determines the play by which the heddles 10 can move in the direction A. The strip inset 32 also preferably is made of plastic and can be affixed in the position shown in FIG. 6 to the rail 6 by, for instance, an adhesive. In practice, however, it is enough to merely loosely insert the inset 32, that is to bond it neither to the rail 6 nor to the heddles 10.
The heddles 10 fitted with hooked open eyes 22, 23 shown in the embodiment of FIGS. 8 and 9 are again associated with the lower rail 7 in such a manner that the rail acts as a drive element to drive the heddles 10 in the direction of the arrow A. Two preferably plastic insets 33, 34 are inserted into the longitudinal recess of the rail 7 and essentially run over the full length of the rail 7. These strip insets 33, 34 constitute drive surfaces 29, 30 associated with the bend of the hooked eye 23 entering the recess of the rail 7.
Insets 17 are inserted in the embodiment of FIGS. 12 and 13 between the lower drive surface 16 of the upper rail 6 and the mating surfaces of the eyes 13 of the heddles 10, and accordingly this embodiment operates in the manner of that of FIGS. 2 and 3. In this embodiment, however, the insets 17 are individual plastic elements inserted into the eyes 13 of the heddles 10 and affixed to them.
FIGS. 14 and 15 show an illustrative embodiment of the invention wherein a tubular element acting as an inset 36 is mounted between a lower drive surface 16 of the rail 6 and a mating surface of the eye 13 of the heddles 10. This inset 36 can implement a contact with the lower drive surface 16 of the rail 6 and direct contact between the upper drive surface 15 and the eye 13. On the other hand, the heddles 10 in the vicinity of the eyes 14 do not make contact with the lower rail in the direction of motion denoted by the arrow A. A pressurized medium is fed into the inset 36 which thereby expands and provides play-less connection between the rail 6 and the heddles 10. The inset 36 is connected to a controlled device .37, for instance a pump for supplying and evacuating the pressurized medium. Illustratively, the medium is water supplied or evacuated by a pump 37. The device is controlled by a control unit 38. The inset 36 runs over the full length of the rail 6 and thereby reliably cooperates with all heddles (FIG. 16). Consequently the inset 36 is at least as long as the zone of the rail holding the heddles 10. In a variation of this embodiment the inset 36 receives compressed air as the pressurized medium. In this instance, the device 37 is a valve unit by which to connect the inset 36 to a source of compressed air.
When a pressurized medium is fed into the tubular inset 36, the latter constrains the heddles 10 to come into direct contact with the upper drive surface 15 of the rail 6 while simultaneously itself setting up contact between the lower drive surface 16 of the rail 6 and the heddles 10. Thereby the heddles 10 are held in play-less manner at the rail 6 and free displacement of the heddles 10 in their lengthwise direction A relative to the rail 6 is precluded. Impacts, vibrations and noise are averted in this manner.
When the pressurized medium is evacuated from the tubular inset 36, the elastic inset 36 resumes its position shown in FIG. 14 and thereupon the heddles 10 can be displaced along the rail 6 in problem-free manner. This approach may be required for instance when ruptured warps must be fixed.
During weaving the device 37 is so controlled by the control unit 38 that the tubular inset 36 is fed with a pressurized medium and accordingly the heddles 10 will be in the position shown in FIG. 15. If warp rupture is ascertained, and the loom stopped, then the device 37 is so controlled by the control unit 38 that the pressurized medium escapes from the inset 36, whereby the heddles 10 thereafter are in the position shown in FIG. 14. When the power loom is started again, the control unit 38 controls the device 37 in such a manner that following a few seconds the pressurized medium is again fed into the inset 36 and thereby the position shown in FIG. 15 is reached again. As a result, following displacement along the rail 6 to repair a warp rupture, the heddles 10 may resume their pre warp-rupture position, before the heddles 10 are made to contact in play-less manner the rail by means of the inset 36.
The control unit 38 contains means which, depending on the mode of the power loom, that is normal weaving, weaving stoppage upon warp rupture, or resumption of weaving following warp rupture, controls whether or not the device 37 supplies the pressurized medium to the inset 36. The loom's operational mode is determined on the basis of warp-rupture signals or loom-starting signals.
The eyes of the heddles 10 which do not make contact with the associated rail 6 or 7 in the harness' direction of motion A only serve to preclude the heddles 10 from shifting in a direction perpendicular to the longitudinal direction A relative to the particular rail 6 or 7. The eyes of the heddles 10 which implement contact with the drive surfaces of one of the rails 6 or 7 in the harness' direction of displacement A obviously also serve to prevent the heddles 10 from moving in a direction perpendicular to their longitudinal direction A relative to the associated rail 6 or 7. By preventing a motion perpendicular to the longitudinal direction A of the heddles, these heddles 10 simultaneously are safe from being bent.
Using a wear-resistant plastic for the particular insets or for the strip-like continuous insets also is advantageous regarding noise.
Whether the heddles 10 are driven by the upper rail 6 or the lower rail 7 depends on the selected weave. As regards weaves for which more harnesses 1 are in the lower shed, for instance for a twill weave, or for a one-three or a two-three weave, driving is preferred by the lower rail 7. For weaves with more harnesses in the upper shed, for instance for two-one or three-one or three-two weaves, driving is preferably by the upper rail 6.
The invention is not limited to the shown embodiments. Differently cross-sectionally contoured rails and/or differently shaped eyes may be easily combined, for instance hooked eyes, or open and closed eyes. | A power loom harness fitted with an upper and a lower cross-sectional contoured rail is arranged to support heddles by extending through eyes at the ends of the heddles. An inset is combined with a first of the rails in order to reduce play, in the direction of motion of the harness, between drive surfaces of the first rail and corresponding mating surfaces of the heddle eyes, so that play between the first rail and corresponding heddle eyes is less than play between the second of the two rails and corresponding heddle eyes, so that the first rail drives the heddle in two directions and the second rails serves a guiding function. | 3 |
This invention was made in the course of work supported by the United States Government, which has certain rights in the invention.
BACKGROUND OF THE INVENTION
This invention relates to agents which decrease the immune response, i.e., immunosuppressive agents.
Cyclosporin A (CsA), a cyclic undecapeptide of fungal origin, and FK506, a neutral macrolide of fungal origin, are potent immunosuppressants. Despite their lack of structural similarities, CsA and FK506 have similar biological properties (Johansson et al., 1990, Transplant. 50:1001; Lin et al., 1991, Cellular Immunol. 133:269). Both molecules interfere with a T-cell receptor-mediated signaling pathway that results in the transcription of early T cell activation genes, although FK506 is able to do so at 100-fold lower concentrations (Tocci et al., 1989, J. Immunol. 143:718).
SUMMARY OF THE INVENTION
In general, the invention features a method of evaluating the immunosuppressive activity of a compound or agent. The method includes: contacting the compound or agent with calcineurin and determining the ability of the compound or agent to bind to the calcineurin, the ability to bind to the calcineurin being positively correlated to the immunosuppressive activity of the compound or agent.
In another aspect, the invention features a method of evaluating the immunosuppressive activity of a compound or agent. The method includes contacting the compound or agent with calcineurin and determining the ability of the compound or agent to modulate the phosphatase activity of the calcineurin, the ability to modulate, e.g., decrease, the phosphatase activity of the calcineurin being correlated to the immunosuppressant activity of the compound or agent.
In preferred embodiments the determination of the ability of the compound or agent to modulate the phosphatase activity includes contacting the compound (or agent)-contacted-calcineurin with a substrate and determining the ability of the compound (or agent)-contacted-calcineurin to dephosphorylate the substrate as compared to the ability of calcineurin which has not been contacted with the compound or agent to dephosphorylate the substrate.
In another aspect, the invention features a method of isolating an immunosuppressive compound or agent. The method includes contacting the compound or agent with calcineurin, allowing the compound or agent to form an affinity complex with calcineurin, and isolating said compound or agent by its affinity for calcineurin.
In another aspect the invention features a method of evaluating the immunosuppressive activity of a compound or agent. The method includes: contacting the compound agent with an immunophilin, e.g., a cyclophilin or an FKBP, and allowing a complex including the compound or agent and the immunophilin to form; contacting the complex with calcineurin; and determining the ability of the complex to bind to the calcineurin. The ability to bind to the calcineurin is positively correlated to the immunosuppressive activity of the compound or agent.
In preferred embodiments the method includes contacting the calcineurin with calmodulin prior to determining the ability of the complex to bind to the calcineurin.
In another aspect, the invention features a method of evaluating the immunosuppressive activity of a compound or agent. The method includes: contacting the compound or agent with an immunophilin and allowing a complex including the compound or agent and the immunophilin to form; contacting the complex with calcineurin; contacting the calcineurin with a substrate; and determining the ability of the calcineurin to dephosphorylate the substrate. The ability to dephosphorylate the substrate is correlated, e.g., inversely correlated, to the immunosuppressant activity of the compound or agent.
In preferred embodiments the method includes contacting the calcineurin with calmodulin prior to determining the ability of the calcineurin to dephosphorylate the substrate.
In another aspect the invention features a method of evaluating the immunophilin-activity of a compound. The method includes: contacting the compound with an immunosuppressive agent, e.g., cyclosporin or FK506, and allowing a complex including the compound and the immunosuppressive agent to form; contacting the complex with calcineurin; and determining the ability of the complex to bind calcineurin. The ability is positively correlated with immunophilin-activity.
In preferred embodiments the method includes: contacting the calcineurin with calmodulin prior to determining the ability of the complex to bind calcineurin.
In another aspect the invention features a method of evaluating the immunophilin-activity of a compound. The method includes: contacting the compound with an immunosuppressive agent, e.g., cyclosporin or FK506, and allowing a complex including the compound and the immunosuppressive agent to form; contacting the complex with calcineurin; contacting the calcineurin with a substrate; and determining the ability of the calcineurin to dephosphorylate the substrate. The ability to dephosphorylate the substrate is correlated, e.g., inversely correlated, to the immunophilin-activity of the compound.
In preferred embodiments the method includes contacting the calcineurin with calmodulin prior to determining the ability of the calcineurin to dephosphorylate the substrate.
In another aspect the inventor features a method for isolating an immunosuppressive compound or agent from a sample. The method includes: contacting the sample with an immunophilin, e.g., a cyclophilin or an FKBP, and allowing a complex to form between the immunophilin and the immunosuppressive compound or agent; and contacting the complex with calcineurin to allow the complex to form an affinity complex with calcineurin.
In preferred embodiments the method includes contacting the calcineurin with calmodulin prior to contacting the complex with calcineurin.
In another aspect the invention features a method for isolating an immunophilin from a sample. The method includes: contacting the sample with an immunosuppressive agent, e.g., CsA or FK506, and allowing a complex to form between the immunophilin and the immunosuppressive agent; and contacting the complex with calcineurin to allow the complex to form an affinity complex with calcineurin.
In preferred embodiments the method includes contacting the calcineurin with calmodulin prior to allowing the affinity complex to form.
In another aspect the invention features a method for isolating a complex including an immunosuppressive agent, e.g., CsA or FK506, and an immunophilin, e.g., an FKBP or a cyclophilin, from a sample. The method includes: contacting the complex with calcineurin; and isolating the complex by its affinity for calcineurin.
In preferred embodiments the method includes contacting the calcineurin with calmodulin prior to isolating the complex.
The invention also includes a: purified preparation of an affinity complex of calcineurin, an immunophilin, e.g., a cyclophilin or an FKBP, and an immunosuppressant, e.g., CsA or FK506; an immunophilin isolated by the methods described herein; an immunosuppressant isolated by the methods described herein; and an affinity complex including an immunophilin and an immunosuppressant isolated by the methods described herein.
In another aspect the invention features a method of treating an animal, e.g., a human, afflicted with a condition characterized by an inhibited or weakened immune response. The method includes increasing the dephosphorylation, preferrably the calcineurin-mediated dephosphorylation, of a substrate which is normally dephosphorylated by calcineurin, e.g., by administering calcineurin.
In another aspect, the invention features a method of treating an animal, e.g., a human, afflicted with a condition characterized by an unwanted immune response, e.g., an autoimmune disease; a cell growth related disorder, e.g., cancer; or transplant rejection. The method includes inhibiting the dephosphorylation of a substrate which is normally dephosphorylated by calcineurin, by administering an effective amount of a selected immunosuppressive compound or agent.
In another aspect, the invention features a method of isolating calcineurin from a sample. The method includes contacting the sample with an immunosupressive compound, or, with a complex including, essentially, an immunophilin, e.g., a cyclophilin or an FKBP, and an immunosuppressive agent, e.g., cyclosporine A or FK506, and isolating calcineurin by its affinity for the compound or the complex.
Immunophilin, as used herein, refers to a molecule capable of forming a complex with an immunosuppressive drug. The complex has greater in vivo or in vitro immunosuppressive activity than does either of the uncomplexed components.
Cyclophilin, as used herein, refers to an immunophilin which complexes with cyclosporine A.
Immunosuppressive agent, or drug, or immunosuppressant, as used herein, refers to a substance which can complex with an immunophilin and which can suppress or weaken the immune response. An immunosuppressive drug complexed with an immunophilin has greater in vivo or in vitro immunosuppressive activity than when in the uncomplexed state.
An immunosuppressive compound, as used herein refers to a substance which can suppress or weaken the immune response, preferrably through an interaction with calcineurin, but which is not necessarily capable of forming a complex with an immunophilin.
Calcineurin, as used herein, refers to any fragment or analog of calcineurin A, calcineurin B, or both, which is capable of complexing with an immunosuppressant-immunophilin complex, e.g., with a FK506/FKBP complex or a CsA/cyclophilin complex.
Complex or affinity complex, as used herein, refers to an association of a receptor and its ligand. The association can include either or both covalent and noncovalent bonds. Immunosuppressive, as used herein, refers to the ability to weaken the immune response.
Immunophilin activity, as used herein, refers to the ability to complex an immunosuppressant and preferably to increase the immunosuppressive activity of the complexed immunosuppressant.
Purified preparation of a substance, as used herein, refers to a preparation which is at least 10% and more preferably at least 50%, 75%, or 90% by weight, preferably dry weight, the substance.
A selected immunosuppressive compound or agent, as used herein, refers to an immunosuppresive compound or agent, other than cyclosporine A or FK506, which inhibits the dephosphorylation of a substrate which is normally dephosphorylated by calcineurin. Preferrably, the selected immunosuppressive compound or agent is isolated by the methods described herein.
The inventors have discovered that complexes between structurally diverse immunosuppressants and their respective immunophilins, e.g., the cyclophilin-A-CsA complex and the FKBP-12 FK506 complex, bind to and inhibit the activity of a common cellular target, the calcium-calmodulin dependent phosphatase calcineurin (also known as PP2B).
The methods and compounds of the invention are useful in the following: the identification of and isolation of immunosuppressive agents; the identification of and isolation of substances, e.g., immunophilins, involved in the immune response; the elucidation of mechanisms of action in the immune response; the suppression of the immune response; and in the treatment of conditions, e.g., AIDS, characterized by a weakened immune response.
Other advantages and features will become apparent from the following descriptions and from the claims.
DETAILED DESCRIPTION
Immunosuppressive Agent-Immunophilin Complexes Bind to Calcineurin and Inhibit its Phosphatase Activity
The experiments described below demonstrate the in vitro binding of a human cyclophilin A-CsA complex and a human FKBP12-FK506 complex to a common cellular target, which is not bound by cyclophilin A, FKBP12, FKBP12-rapamycin, or FKBP12-506BD. The target is a complex of 61 kDa calcineurin A, 19 kDa calcineurin B (collectively referred to as calcineurin, which is a Ca 2+ , calmodulin-dependent serine/threonine-phosphatase (Klee et al., 1978, Biochemistry 7:1205; Klee et al., 1979, Proc. Natl. Acad. Sci USA 76:6270; Stewart et al., 1982, FEBS Lett. 137:80) and calmodulin. Calcineurin was found to meet the biochemical requirements of the common target of immunosuppressive agent-immunophilin complexes and thus of a component of T-cell receptor-(TCR) and IgE receptor-signaling pathways involved in transcription and exocytosis.
As shown in Experiment 3 below, proteins of M r 61,000, 57,000, 17,000, and 15,000 from calf thymus were retained on FKBP 12-based affinity matrices only when the affinity matrices had been preloaded with FK506. Affinity matrices based on FKBP12, FKBP12-rapamycin, CsA, FK506, and rapamycin do not retain any of these proteins. The 17-kDa protein was identified as calmodulin, the 61-kDa and 57-kDa proteins as calcineurin A, and the 15-kDa protein as calcineurin B, as shown in Experiment 6 below.
Calcineurin is a Ca 2+ , calmodulin-dependent serine/threonine phosphatase previously shown to be the predominant calmodulin-binding protein in T lymphocytes (Kincaid et al., 1987, Nature 330:176). The gel mobilities on SDS-PAGE reported for calcineurin-A (61 kDa), calcineurin-B (19 kDa, M r 15,000 on SDS-PAGE), and calmodulin (17 kDa) and the proteins described above are the same as described above. Furthermore, calcineurin-A has been reported to undergo a facile proteolytic cleavage of a C-terminal peptide to yield a 57 kDa fragment (Hubbard et al., 1989, Biochemistry 28:1868). Treatment of the eluted proteins with Ca 2+ prior to gel electrophoresis resulted in a gel mobility shift for the M r 15,000 and 17,000 bands that are characteristic of myristoylated calcineurin-B and calmodulin (Klee et al., 1979, Proc. Natl. Acad. Sci. USA 76:6270), respectively. Blotting experiments with anti-calcineurin antibodies and 45 Ca 2+ , provide further support for the identification of the M r 61,000, 57,000, 17,000, and 15,000 bands as calcineurin-A, the C-terminal peptide cleavage product of calcineurin-A, calmodulin, and calcineurin-B, respectively.
Elution of the proteins from the immunosuppressive agent-immunophilin matrix was achieved with soluble cyclophilin-A-CsA or FKBP-12-FK506 complexes, as shown in Experiment 3 below. These results suggest the two immunosuppressive agent-immunophilin complexes bind to the common target competitively. The sensitivity of Ca 2+ -dependant signaling pathways to both CsA and FK506 is probably related to the finding that a calcium chelator, EGTA, is able to effectively elute the four proteins, as shown in Experiment 4 below.
The primary immunosuppressive agent-immunophilin interaction site within the target calcineurin-calmodulin complex was shown, in Experiment 6 below, to reside within calcineurin by affinity experiments with calcineurin samples that lacked calmodulin. In these experiments, only the cyclophilin-CsA and FKBP-FK506 matrices were able to retain purified calcineurin, as described below.
The phosphatase inhibition studies described in Experiment 6 below confirm the identity of calcineurin as the primary site of interaction. The influence of immunophilins or immunophilin-drug complexes on the phosphatase activity of calcineurin in the presence of Ca 2+ and calmodulin was assayed with both paranitrophenyl phosphate and a phosphopeptide substrate (H 2 N-Asp-Leu-Asp-Val-Pro-Ile-Pro-Gly-Arg-Phe-Asp-Arg-Arg-Val-Ser-(OPO 3 .sup.2-)Val-Ala-Ala-Glu-CO 2 H) (Sequence I.D. No. 1). In accord with the binding studies, a specific effect is seen with the complexes of both cyclophilin-A-CsA and FKBP-12-FK506. Whereas these complexes induce a slight increase in the phosphatase activity of calcineurin-Ca 2+ /calmodulin (by a factor of ca. 2-3) towards para-nitrophenyl phosphate, they potently inhibit activity towards the phosphopeptide substrate in the presence or absence of calmodulin. These results suggest that the biological function of the immunophilin-drug complexes may be to inhibit phosphatase activity of calcineurin, but that this may be achieved by binding to a site adjacent to the active site, rather than to the active site. The small para-nitrophenyl phosphate reagent presumably interacts with calcineurin nearly exclusively via active site residues, whereas the phosphopeptide, which is comprised of a sequence derived from the phosphorylation site on the RII subunit of cyclic AMP-dependent protein kinase (a calcineurin substrate) (Blumenthal et al., 1986, J. Biol. Chem 261:8140), is presumed to make extensive contact with the enzyme. In both phosphatase assays, no effect was observed with cyclophilin- A, FKBP-12, CsA, FK506, or rapamycin alone, or with the FKBP 12-rapamycin and FKBP12-506BD complexes.
These biological investigations suggest the calcium/calmodulin dependent phosphatase calcineurin is the common "downstream" biological target of CsA and FK506. As these agents exhibit specificity for activation pathways that induce an increase in intracellular Ca 2+ -concentration, such as those mediated by the TCR and IgE receptor, calcineurin may be involved in regulating the phosphorylation state of a downstream component of these signaling pathways. This model is able to reconcile the effects of CsA and FK506 on the disparate processes of exocytosis and transcription. For example, dephosphorylation of a cytoplasmic transcription factor-anchor protein complex would initiate nuclear translocation of the cytoplasmic unit of a transcription factor (e.g., NF-AT) resulting in transcription, whereas dephosphorylation of a "secretory vesicle transport protein" (e.g., synapsin I) would initiate exocytosis. The cellular specificity of the actions of CsA and FK506 may be related to their selective interactions with specific isoforms of calcineurin or due to the existence of cell-specific calcineurin substrates.
The identification of a common phosphatase target of cyclophilin A-CsA and FKBP12-FK506 complexes also provides support for the hypothesis that immunophilin-ligand complexes are the agents responsible for inhibition of cytoplasmic signaling. In this model, the immunophilin is not necessarily a component of the signaling pathway--its role in the uncomplexed state is not specified. Only upon complexation with its immunosuppressive ligand is an inhibitory complex formed.
CsA and FK506 appear to exhibit a novel mechanism of action. These molecules apparently "hijack" constitutively expressed cellular proteins to form an inhibitory complex that further interacts with a component of the signal transduction pathway to form a ternary complex. The ability of the immunosuppressants to bring together two proteins is reminiscent of the role of antigenic peptides, which mediate the binding of MHC molecules to the polymorphic TCRs. Especially interesting in this regard is the apparent ability of FKBP12 to present two ligands (FK506 and rapamycin) to distinct cellular targets.
As cyclophilin A is the predominant T cell and mast cell cyclophilin isoform, and is found in the cytosol, it appears that it is primarily responsible for mediating the actions of CsA in these cell lines. Other cyclophilin isoforms may mediate the actions of CsA analogs that bind weakly to cyclophilin A, yet have potent immunosuppressive activity. Although it is possible that these analogs may bind directly to calcineurin without the need for presentation by cyclophilins, a more likely possibility is that the complexes of cyclophilin A with these CsA analogs may bind to calcineurin with increased affinity (relative to the cyclophilin A-CsA complex). FK506 analogs with analogous properties may be analyzed in a similar matter.
The competitive binding of cyclophilin A-CsA and FKBP12-FK506 to calcineurin is interesting in light of the absence of apparent structural similarities between the immunophilins cyclophilin A and FKBP12, and their ligands CsA and FK506. It is possible that different binding elements within the same binding site on calcineurincalmodulin are used by these direct immunophilin-drug complexes.
Experiment 1
Construction of a Glutathione S-Transferase-FKBP12 fusion protein
To facilitate the expression, purification, and solid state immobilization of FKBP12, a fusion of FKBP12 encoding DNA to glutathione S-transferase encoding DNA was made. (Early binding studies involved covalently derivatized (e.g., biotinylated) immunophilins used in the context of ligand blotting, expression screening, and affinity chromatography techniques. The covalent modification of FKBP12 resulted, however, in significant reduction in drug affinity.)
A chimeric gene encoding glutathione S-transferase-FKBP12 fusion protein (GFK) was constructed by fusing the cDNA encoding FKBP12 (Standaert et al., 1990, Nature 346:671, hereby incorporated by reference) to the DNA encoding carboxyl terminus of glutathione S-transferase (Smith et al., 1988, Gene 67:31, hereby incorporated by reference). FKBP12 was amplified by PCR from an FKBP12 coding plasmid (pRFS) (Standeart et al., 1990, supra) using two primers: 5' primer, 5'-CAGGACACAGGATCCATGGGCGTGCAGGTGGA-3' (Sequence I.D. No. 2); 3' primer, 5'-GCTGGCTAACGAATTCAAGGGAGGAGGCCATTCCTGTCAT-3' (Sequence I.D. No. 3). The PCR fragment was purified by phenol-chloroform extraction and ethanol precipitation. It was then digested with EcoRI and BamHI and cloned into pGEX-2T (Smith et al., 1988, Supra), which had been linearized with the same restriction enzymes. The fusion construct, pGFK12, was transformed into E. coli XA90 (G.L. Verdine, Harvard University ) in which the expression of GFK can be induced with isopropyl-β-D-thiogalactopyranoside (IPTG).
Experiment 2
Purification of the GKF Fusion Protein
After transformation of the resulting construct pGFK12 into E. coli XA90, induction with IPTG yielded the fusion protein GFK as the major constituent of soluble, cellular proteins. GFK was partially purified by ammonium sulfate fractionation (40-80%), glutathione affinity chromatography, and DE 52 anion exchange chromatography. The purification was performed as follows. A 1 liter LB culture of XA90/pGFK12 was incubated at 37° C. At an OD 595 of 0.65, the culture was induced with 1 mM IPTG. The cells were harvested 6h after induction, resuspended in 20 mL of 20 mM Tris HCl (pH 7.8) with 1 mM PMSF, and lysed by two passes through a French press at 12,000 psi. The nucleic acids were precipitated by addition of one fifth volume of neutralized 2% protamine sulfate solution to the crude lysate followed by centrifugation (20,000×g, 20 min.). The crude cell extract was then fractionated with ammonium sulfate and the 40-80% protein pellet was resuspended in 30 mL of 20 mM TrisHCl (pH 7.8) and dialyzed against 4 liters of the same buffer.
The dialyzed protein solution was first purified with glutathione Sepharose as described previously (Smith et al. 1988, supra). The glutathione (5 mM) eluent from the glutathione sepharose affinity column was directly loaded onto a DE 52 column that had been equilibrated with 5 column volumes of 20 mM TrisHCl (pH 7.8). The column was then washed with another 5 column volumes of the buffer and the fusion protein was eluted with a step gradient of 0-200 mM KCl. GFK-containing fractions were collected and used directly.
GFK fractions after DE 52 chromatography were nearly homogeneous as judged by Coomassie blue staining. However, several other protein bands were visible with silver stain.
The rotamase activity of GFK and its ability to be inhibited by FK506 and rapamycin were determined in the presence and absence of reduced glutathione. GFK has rotamase activity and affinities for FK506 and rapamycin similar to those of recombinant human FKBP12; furthermore, neither its rotamase activity nor affinities for the drugs are affected by the presence of glutathione. Thus, it appears that immunophilin and glutathione S-transferase domains act independently in the fusion protein.
Experiment 3
A Common Set of Proteins Bind to Cyclophilin-CsA and FKBP-FK506, but not Cyclophilin, FKBP, CsA, FK506, Rapamycin, or FKBP-Rapamycin
Several factors were taken into account in the design of the first glutathione-Sepharose adsorption experiment. Since both CsA and FK506 inhibit Ca 2+ -dependent signaling pathways, Ca 2+ and Mg 2+ were included in the incubation buffer (see below). In addition, in some experiments, a homobifunctional cross-linking reagent, dimethyl 3,3'-dithiobispropionimidate (DTBP) (Wang et al. 1974, J. Biol. Chem. 249:8005) was added to the incubation mixture to retain target proteins whose affinity for immunophilin or immunophilin-drug complex was not sufficient to withstand the washes following adsorption of the complex to the solid phase. Under these conditions, four proteins of M r 61,000, 57,000, 17,000, and 15,000 from calf thymus extract were found to be specifically adsorbed by the GFK-FK506 complex but not by GFK alone or the GFK-rapamycin complex. Subsequently, it was found that the affinity of these four proteins for GFK-FK506 was sufficiently high that the cross-linking reagent was not necessary. Furthermore, the same set of proteins was detected in other tissues such as bovine brain and spleen, with brain being the most reliable source.
Adsorption of calcineurin-calmodulin with GFK-FK506 using glutathione Sepharose was performed as follows. Crude tissue extracts, fresh bovine calf brain, thymus, or spleen (Research 87, Revere, MA), were homogenized (1:3 W/V) in 20 mM Tris HCl (pH 6.8), 0.25 mM NaCl, 2 mM β-mercaptoethanal, 0.02% NaN 3 , 1 mM PMSF, and 5% glycerol. The homogenate was centrifuged at 8,000×g for 4 h. The supernatant was separated and the pellet was resuspended in an equal volume of the same buffer. Centrifugation at 8,000 ×g for 4 h gave a second supernatant. The two supernatants were mixed (1:1 v/v) and centrifuged at 30,000×g for 45 min. The supernatant was then filtered through a 0.45 μm filter and kept at 4° C. before use.
The crude tissue extracts were pre-incubated with glutathione Sepharose (about 1:100 to 1:200 dilution of the sepharose) at 4° C. for 1-3 h to remove the endogenous glutathione binding proteins, including glutathione S-transferases. A typical incubation mixture had a total volume of 0.2 mL consisting of buffer A (50 mM Tris HCl (pH 7.5), 100 mM NaCl, 2 mM MgCl 2 , 2 mM CaCl 2 ), 2 μM GFK, 20 μM FK506 (or rapamycin or CsA) and 0.05 to 0.1 mL tissue extracts. After incubation at 4° C. on a nutator for 1.5 h, 25 μL of 50% (V/V) glutathione Sepharose in buffer A was added and incubation was continued for an additional 0.5 to 2 h. The Sepharose beads were precipitated by centrifugation on a microcentrifuge at 5,000×g for 2 min. The glutathione Sepharose beads were washed three times with 0.5 mL buffer A containing 0.2% Triton X-100. The washed glutathione Sepharose was then resuspended in 25 μL of 2× SDS sample buffer, heated in boiling water for 3 min, and centrifuged for 2 min. The supernatant was subjected to SDS-PAGE followed by silver staining. For purification of the target proteins from calf thymus and brain extracts, each of the components was scaled up proportionally and the proteins were eluted with 20 mM EGTA in 50 mM Tris-HCl, pH 7.4 and 1 mM dithiothreitol after three washes with buffer A containing 0.2% Triton X-100.
Competitive binding experiments showed that both GFK-FK506 and cyclophilin A-CsA bind to the same set of proteins. A competitive binding experiment was carried out with recombinant FKBP12 and cyclophilin A (Standaert et al., 1990, supra, Lui et al., 1990, Proc. Natl. Acad. Sci. 87:2304) and their respective drug complexes. After the set of four target proteins were adsorbed onto the glutathione Sepharose affinity matrix, elution was attempted with immunophilins, the drugs, or the immunophilin-drug complexes. The set of four proteins were eluted from glutathione-sepharose immobilized GFK-FK506 with both recombinant complexes. In contrast, these proteins were not eluted by free immunophilins or unbound drugs. In addition, the FKBP12-rapamycin complex did not elute the target proteins, in agreement with previous observation.
Experiment 4
Divalent Metal Ion-Dependence of Immunophilin-Drug/Target Protein Complex Formation and Purification of the Target Proteins by EGTA Elution
When Ca 2+ and Mg 2+ were accidentally omitted from the incubation buffer, no target proteins were retained by GFK-FK506. To further test the importance of divalent metal ions for interaction between immunophilin-drug complexes and target proteins, the adsorption experiment was performed in the presence of the Ca 2+ chelator EGTA. GFK-FK506 complexes no longer retained the target proteins when EGTA was present. In addition, EGTA was found to be capable of eluting the four proteins from the GFK-FK506 complex immobilized on glutathione sepharose without a significant effect on the interactions between GFK and glutathione sepharose. This proved to be an effective way of purifying the target proteins.
GFK-FK506 bound to glutathione Sepharose matrix was loaded with calf thymus extract and eluted with EGTA. Two contaminant proteins were seen to coelute with the four target proteins, the 38kDa GFK and a less abundant M r 26,000 protein that may be a glutathione S-transferase either from the proteolytic cleavage of GFK or from the calf thymus extract. With this procedure, over 40 μg of proteins can be purified from 20 mL of calf thymus extract (120 mg of protein).
Experiment 5
Identification of the 17-kDa Protein as Calmodulin, the 61-kDa and 57-dDa Proteins as Calcineurin A, and the 15-kDa Protein as Calcineurin B
The metal ion-dependency (especially Ca 2+ -dependency) binding of the target proteins to the immunophilin-drug complexes supported the possibility that the M r 17,000 protein was calmodulin. One of the distinctive properties of calmodulin is its Ca 2+ -dependant gel mobility shift, i.e., calmodulin migrates faster in the presence of Ca 2+ during SDS-polyacrylamide gel electrophoresis (Klee et al., 1979, Proc. Natl. Acad. Sci. USA 76:6270). Indeed, when the EGTA eluent was subjected to SDS-PAGE beside a calmodulin standard (Sigma), the M r 17,000 protein bands exhibited the Ca 2+ -dependent gel mobility shift characteristic of calmodulin. Thus, the M r 17,000 protein is most likely calmodulin.
These results supported the possibility that the remaining three proteins could be part of a multi-subunit complex of calmodulin binding proteins, such as a Ca 2+ , calmodulin-dependent kinase or Ca 2+ , calmodulin-dependent phosphatase. Calcineurin is composed of two subunits, calcineurin A, a 61-kDa polypeptide, and calcineurin B, a 19-kDa polypeptide. As the 19-kDa calcineurin B migrates at about 15-kDa on SDS-PAGE, the M r 61,000 and 15,000 proteins could be calcineurin A and B respectively. It was also known that calcineurin A undergoes proteolysis to yield a 57-kDa protein.
When the four target protein bands were blotted onto PVDF membranes and subjected to N-terminal sequencing, they were all found to be N-terminally blocked. This is in agreement with the fact that both subunits of calcineurin, the 57-kDa proteolytic fragment of calcineurin A, and calmodulin have covalent modifications of their N-termini (Klee et al., 1988, supra, Aitken et al., 1984, Eur. J. Biochem. 139:663; Klee and Vanaman, 1982, Adv. Prot. Chem. 35:213). More importantly, 25- and 20-amino acid tryptic fragments derived from the M r 61,000 and 15,000 proteins obtained from the affinity experiments were sequenced by automated Edman degradation and shown to be 100% identical to sequences in calcineurin A Ser Gln Thr Thr Gly Phe Pro Ser Leu Ile Thr Ile Phe Ser Ala Pro Asn Tyr Leu Asp Val Tyr Asn Asn Lys. (Sequence I.D. No. 4) and calcineurin B Ile Tyr Asp Met Asp Lys Asp Gly Tyr Ile Ser Asn Gly Glu Leu Phe Gln Val Leu Lys. (Sequence I.D. No. 5), respectively.
Calcineurin B is a calcium binding protein with four Ca 2+ -binding "EF" hands (Aitken et al., 1984, supra) and, like calmodulin, exhibits a gel mobility shift in the presence of calcium during SDS-PAGE. The M r 15,000 EGTA-eluted protein migrated faster in the presence of calcium. It was also found to comigrate with a calcineurin B standard (Sigma) in the presence or absence of calcium. The M r 61,000 and M r 57,000 EGTA-eluted proteins comigrate with a calcineurin A standard (Sigma), which do not undergo a gel-mobility shift in the presence of Ca 2+ .
A western blot of the EGTA eluant from calf thymus with polyclonal antibodies against bovine brain calcineurin further established that the M r 61,000, 57,000, and 15,000 proteins are calcineurin A, a proteolytic fragment of calcineurin A, and calcineurin B, respectively. A 45 Ca 2+ ligand blotting experiment with the EGTA eluant further supports the identify of the 15-kDa protein as calcineurin B. The weaker response of calmodulin ( r 17,000) was anticipated as it is known that under the same blotting conditions calmodulin provides a weaker signal.
Western blots of calcineurin, gel mobility shift of calmodulin and calcineurin B, and detection of calcineurin B by 45 Ca autoradiography were performed as follows.
For the Western blot of calcineurin A and B, the proteins were subjected to 12% SDS-PAGE followed by electroblotting onto nitrocellulose using a Bio-Rad Mini-blotting apparatus. Development of the blot with rabbit anti-calcineurin IgG and alkaline phosphatase conjugated goat-anti-rabbit IgG was performed as previously described (Burnette, 1981, Anal. Biochem. 112:195). To detect the calcium-dependent gel mobility shift of calmodulin and calcineurin B, Ca 2+ , (1 mM) or EGTA (5 mM were added to the protein solution in SDS sample loading buffer before loading the gel. The 45 Ca 2+ -binding to calcineurin B and calmodulin and subsequent autoradiography were carried out as previously described (Maruyama et al., 1984, J. Biochem. 95:511). The 45 Ca 2+ was purchased from New England Nuclear (Cambridge, Mass.).
Experiment 6
Calcineurin Binds to FKBP-FK506 and Cyclophilin-CsA in a Ca 2+ -Dependent Fashion, and its Phosphatase Activity Towards a Phosphopeptide Substrate is Specifically Inhibited by the Two Immunophilin-Drug Complexes
The binding between calcineurin and the immunophilin-drug complexes was studied with calcineurin purified from bovine brain. Calcineurin was found to be retained by GFK-FK506, but not GFK, or GFK-rapamycin. Since calmodulin was precipitated together with calcineurin from bovine brain and thymus extracts, it remained to be established whether the FKBP-FK506 complexes bind to calcineurin or calmodulin, and whether binding requires the prior formation of the calcineurin-calmodulin complex. These questions were addressed by experiments that demonstrated that the GFK-FK506 complex binds directly to calcineurin in the presence of Ca 2+ without calmodulin, and that the binding is dependent on Ca 2+ and Mg 2+ . In the presence of calmodulin, however, increased amounts of calcineurin (both A and B subunits) appear to be adsorbed by the same amount of GFK-FK506 complex, and calmodulin is retained as well. The binding of calcineurin-calmodulin by GFK-FK506 was abolished by EGTA. Calmodulin alone does not bind to the GFK-FK506 complex in the presence of calcium.
Calcineurin is known to be a Ca 2+ , calmodulin-dependent protein phosphatase (Stewart et al., 1982, FEBS. Lett. 137:80). Using a phosphorylated peptide fragment from the regulatory subunit of cAMP-dependent kinase as a substrate, the phosphatase activity of the calcineurin was assayed in the presence of the immunophilins, the individual drugs, and their respective complexes with or without calmodulin. Both the intrinsic Ca 2+ -dependent and Ca 2+ , calmodulin-stimulated phosphatase activities of calcineurin are potently inhibited by FKBP12-FK506 and cyclophilin A-CsA complexes, in agreement with the glutathione Sepharose adsorption experiments. It is worth noting that complexes of FKBP-rapamycin and FKBP-506BD do not significantly inhibit the phosphatase activity, in full agreement with the competitive binding assay and the previous observations that rapamycin inhibits different, calcium-independent signaling pathways and that 506BD, although a potent rotamase inhibitor of FKBP12, does not inhibit TCR-mediated signaling.
Calcineurin phosphatase assays were carried out essentially as described previously (Manalan et al. 1983, Proc. Natl. Acad. Sci. USA 80:4291) with minor modifications. The substrate used was a synthetic peptide corresponding to the phosphorylation site of the RII subunit of cyclic AMP-dependent protein kinase Asp Leu Asp Val Pro Ile Pro Gly Arg Phe Asp Arg Arg Val Ser Val Ala Ala Glu. (Sequence I.D. No. 1), which was phosphorylated with 32 p-labeled ATP at the serine residue. The assay buffer consists of 40 mM TrisHCl (pH 7.5), 0.1 M NaCl, 6 mM MgCl 2 , 0.1 mM CaCl 2 , 0.1 mg/mL bovine serum albumin, and 0.5 mM dithiothreitol. The assay mixture (60 μl) contained 40 nM calcineurin, and 80 nM calmodulin (when present), and 2 μM phosphopeptide in addition to the assay buffer. It was found that the presence of methanol (3%) inhibits the phosphatase activity significantly. Therefore, the drug solutions were prepared in DMSO as follows. DMSO stock solutions of the drugs were prepared (3000×final concentration) and then diluted 100×with the assay buffer. 2 μL was added to the incubation mixture giving a final concentration of DMSO of less than 0.04% in the final assay mixture. The incubations were carried out at 30° C. for 10 min before the reaction was stopped by addition of the stop solution (5% trichloroacetic acid, 0.1 M potassium phosphate) and loaded onto 0.5 ml Dowex AG 50W-X8 (200-800 mesh, Bio-Rad) columns. After the [ 32 P]-inorganic phosphate was eluted from the column, it was mixed with 12 ml of ScintiVerse II (Fisher Scientific) and counted on a Beckman LS1801 Liquid Scintillation Systems. Bovine brain calcineurin and calmodulin were purchased from Sigma Chemical (St. Louis, Mo.). 32 P-labeled phosphorylated peptide substrate, bovine brain calcineurin, and rabbit anti-calcineurin IgG were generous gifts from Dr. Claude B. Klee (National Cancer Institute, Department of Biochemistry). Goat-anti-rabbit IgG conjugated with alkaline phosphatase and the alkaline phosphatase substrates (BCIP and NBT) were obtained from Pierce (Rockford, ILL.). Glutathione Sepharose 4B was from Pharmacia LKB (Uppsala, Sweden). 506BD was prepared by Thomas J. Wandless and Patricia K. Somers in the Harvard laboratory.
Use
The methods of the invention can be used to treat an animal, e.g., a human, suffering from a condition characterized by a weakened immune response, e.g., AIDS. Dosages will vary based on factors known to those skilled in the art, e.g., the condition of the patient, the potency of the treatment, and the desired therapeutic effect.
Other Embodiments
Other embodiments are within the following claims, e.g., the affinity of immunosuppressive agents or immunosuppressive agent-immunophilin complexes for calcineurin can be used to identify and purify new immunosuppressive agents and immunophilins. Calcineurin could be immobilized on a solid state matrix and contacted with a sample containing a complex of an immunosuppressive agent and an immunophilin to purify the complex. The components of the complex could subsequently be separated and purified.
A specific immunosuppressive agent, e.g., CsA or FK506, could be added to a sample to allow the formation of complexes between the added immunosuppressive agent and an immunophilin in the sample. Likewise an immunophilin could be added to a sample to form complexes with an immunosuppressant in the sample.
The immunosuppressive activity of a compound can be determined by the ability of a complex containing the compound and an immunophilin, e.g., cyclophilin or FKBP, to bind to calcineurin, or by the ability of the complex to alter the phosphatase activity of calcineurin. Likewise the immunophilin-activity of a compound can be determined by the ability of a complex containing the compound and an immunosuppressant, e.g., FK506 or CsA, to bind to calcineurin, or by the ability of the complex to alter the phosphatase activity of calcineurin.
The ability of immunosuppressive compounds to bind to calcineurin or to alter the phosphatase activity of calcineurin can be used to purify or isolate the compounds. Purification or isolation can be based directly on the affinity of the compounds for calcineurin or on the use of binding or phosphatase activity as an assay for the presence of the compounds.
__________________________________________________________________________SEQUENCE LISTING(1) GENERAL INFORMATION:(iii) NUMBER OF SEQUENCES: 5(2) INFORMATION FOR SEQ ID NO: 1:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 19(B) TYPE: amino acid(C) STRANDEDNESS:(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 1:AspLeuAspValProIle ProGlyArgPheAspArgArgValSerVal51015AlaAlaGlu19(2) INFORMATION FOR SEQ ID NO: 2:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 32(B) TYPE: nucleic acid (C) STRANDEDNESS: single(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 2:CAGGACACAGGATCCATGGGCGTGCAGGTGGA32(2) INFORMATION FOR SEQ ID NO: 3:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 40(B) TYPE: nucleic acid(C) STRANDEDNESS: single(D ) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 3:GCTGGCTAACGAATTCAAGGGAGGAGGCCATTCCTGTCAT40(2) INFORMATION FOR SEQ ID NO: 4:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 25(B) TYPE: amino acid(C) STRANDEDNESS:(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 4:SerGlnThrThrGlyPheProSerLeuIleThrIlePheSerAlaPro51015AsnTyrLeuAspValTyrAsnAsnLys202 5(2) INFORMATION FOR SEQ ID NO: 5:(i) SEQUENCE CHARACTERISTICS:(A) LENGTH: 20(B) TYPE: amino acid(C) STRANDEDNESS:(D) TOPOLOGY: linear(xi) SEQUENCE DESCRIPTION: SEQ ID NO: 5:IleTyrAspMetAspLysAspGlyTyrIleSerAsnGlyGluLeuPhe5 1015GlnValLeuLys20 | A method of evaluating the immunosuppressive activity of a compound including contacting the compound with calcineurin and determining the ability of the compound to bind to the calcineurin. The ability to bind to the calcineurin is positively correlated to the immunosuppressive activity of the compound. | 8 |
FIELD OF THE INVENTION
[0001] The present invention is related to the field of liquid toner imaging systems and in particular to the coating of various parts of the system to avoid sludge.
BACKGROUND OF THE INVENTION
[0002] Coating of parts of a liquid toner imaging system in order to avoid agglomerations of toner particles, colloquially known as “sludge”, is well known. In general, such coatings comprise silicone or fluorosilicone materials. Surfaces normally treated include surfaces to which the toner would normally plate due to an electric field, metal surfaces on which the toner sits for extended periods of time or in regions in which the toner is subjected to other types of stress.
[0003] In WO 90/05941, the disclosure of which is incorporated herein by reference, coating of surfaces onto which toner particles would plate, due to an electric field, is described. The coatings described include fluorosilicones and Zonyl a brand name for a series of Dupont fluorosurfactants. The Zonyl material is described (incorrectly) as a fluorosilicone. With respect to the use of Zonyl as a coating the reference states “Alternatively, coating the developer electrode with fluorosilicone surfactants such as Zonyl (DuPont) has been effective in inhibiting plating out of toner particles, but this expedient inhibits plating-out of toner particles for only a limited period of time.”
SUMMARY OF THE INVENTION
[0004] A general aspect of some embodiments of the invention is concerned with the use of fluorosurfactants having anionic groups as coating materials.
[0005] In an exemplary embodiment of the invention, such materials are coated onto surfaces that are to be protected from sludge formation, for example metal and especially aluminium parts. One method of coating is to dip the part to be protected from sludge into the surfactant and to allow the coating to surfactant to dry. Surprisingly, it has been found that not only does the material remain on the metal substantially permanently, but also that it is effective for protecting against the formation of sludge.
[0006] The formation of sludge, once thought to occur only where the toner was subject to plating or other stress, has been found to also be formed on surfaces which are not subject to an electric field or other stress and to which the liquid toner is periodically applied (as for example, when the imager is operating). It is believed that small amounts of the toner is left on the surfaces and on drying, attaches itself to the surface forming a focus for the formation of sludge on subsequent wettings of the surface with liquid toner This effect may be enhanced when the liquid toner comprises particles formed with fibrous extensions.
[0007] There is thus provided, in accordance with an exemplary embodiment of the invention, a metal product having a coating on at least a portion thereof, the coating having a thickness of between about 0.1 and about 2 microns thereon, said coating comprising an anionic fluorosurfactant
[0008] Optionally, the coating comprises more than 50% by weight of said surfactant.
[0009] There is further provided, in accordance with an embodiment of the invention, a metal product having a coating thereon said coating comprising an anionic fluorosurfactant in an amount greater than 50% by weight.
[0010] Optionally, the fluorosurfactant includes chemical anchors to bond it to the metal surface.
[0011] There is further provided, in accordance with an embodiment of the invention, a metal product coated with a fluorosurfactant having chemical anchors to bond it to the metal surface.
[0012] Optionally, the coating comprises more than 80%, 90%, 95% or 99% by weight of said surfactant.
[0013] In an embodiment of the invention, the surfactant comprises a material having the formulation: (RfCH 2 CH 2 O) x P(O)(OH) y , where Rf=F(CF 2 CF 2 ) z ; x=1 or 2; y=2 or 1; x+y=3; z=1 to about 7.
[0014] Alternatively or additionally, the surfactant comprises a material having the formulation: RfCH 2 CH 2 SCH 2 CH 2 CO 2 Li, where Rf=F(CF 2 CF 2 ) x and x=1 to about 9.
[0015] Alternatively or additionally, the surfactant comprises a material having the formulation: (RfCH 2 CH 2 O) x PO(ONH 4 ) y , where Rf=F(CF 2 CF 2 ) z ; x=1 or 2; y=2 or 1; x+y=3 and z=1 to about 7.
[0016] Alternatively or additionally, the surfactant comprises a material having the formulation: (RfCH 2 CH 2 O) x PO(ONH 4 ) y where Rf=F(CF 2 CF 2 ) z where x=1 or 2; y=2 or 1; and z=1 to about 7; x+y=3.
[0017] Optionally, the metal is aluminum.
[0018] Optionally, the thickness is greater than about 0.3 or 0.5 micrometers. Optionally, the thickness is less than about 1 micrometer.
[0019] There is further provided, a liquid toner imaging system having at least one metal product, according to the above description, said coating being in contact with liquid toner therein.
[0020] Optionally, the metal product includes at least one surface that is not in continuous contact with the liquid toner
[0021] Optionally, the metal product has at least one surface in contact with liquid toner that is not subject to an electric field that would tend to plate toner particles onto the surface. Optionally, none of the coated surfaces of the metal product that are in contact with liquid toner are subjected to an electric field that would tend to plate toner particles onto the surface. Optionally, none of the coated surfaces that are in contact with liquid toner are subjected to any substantial electric field.
BRIEF DESCRIPTION OF THE DRAWING
[0022] Exemplary, non-limiting embodiments of the invention are described with reference to the following drawing.
[0023] [0023]FIG. 1 is a schematic cross-sectional view of part of an imaging system in which the present invention has been tested.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0024] [0024]FIG. 1 shows a cross-sectional view of a development system 10 in which the formation of sludge was unexpectedly encountered. Similar systems have been described in the past in patents and patent applications of the assignee of the present application. It should be noted that the particular device chosen does not form a part of the present invention and is described here for reference purposes only to illustrate a use of the invention.
[0025] A latent image is formed on an imaging surface such as a photoreceptor 12 , by means that are not shown. Many methods of forming such latent images are well known in the art and the latent image can be temporary (as when an organic or selenium based photoreceptor is used) or can be permanent.
[0026] A developer apparatus 14 is used to develop the latent image with a liquid toner to form a developed image on imaging surface 12 for subsequent transfer to a substrate such as paper or plastic (not shown).
[0027] The exemplary development system shown is encased in a housing 15 . An electrode 16 is formed in two parts, a main electrode 18 and a back electrode 20 . Both the main and back electrodes are operatively associated with a developer electrode 22 , shown in the form of a developer roller. Electrode 16 is formed with a cavity 24 into which liquid toner is introduced via a toner input portal 26 . The liquid toner is forced by pressure via a passage 28 to enter narrow spaces between electrodes 18 and 20 and developer electrode 22 . Main and back electrodes 18 and 20 , on the one hand and developer electrode 22 on the other hand are electrified to different voltages, so that the charge toner particles are plated onto the developer electrode, providing a thin concentrated layer of toner particles. A, preferably electrified, squeegee roller 30 removes liquid from the plated concentrated developer to form a more concentrated layer. The layer is imagewise transferred to those portions of the latent image that are electrified to attract it, with developer roller preferably being electrified to aid in the transfer of the layer to image areas of the latent image and to prevent transfer to background areas of the latent image. All or a part of the thickness of the layer may be transferred, as known in the art.
[0028] A cleaning system 32 , comprising, in the exemplary embodiment shown, a cleaning roller 34 , a scraper 36 a sponge roller 38 and a squeezing roller 40 , is used to remove the layer (or portions of a layer) that remain on the developer roller. This material can be stored in the space 42 between electrode 16 and housing 15 , or it may be removed from the housing for reuse.
[0029] Sludge is believed to form at surfaces at which plating of the toner can take place and also in areas in which toner is left in contact with a metal surface, at which the toner particles can be discharged and aglomerate.
[0030] It should be understood that, utilizing prior art thinking, no sludge should form in the liquid toner path prior to the developer roller, since toner is not subject to any electrical stresses in this region and since the toner drains from space 24 when the imaging system is idle. This region is not subject to an electric field, except for the fields between electrode 16 and roller electrode 22 and the field between roller electrode 22 and squeegee roller 30 . However, these fields cause plating onto the developer roller and thus should not cause sludge in the system.
[0031] Nevertheless, sludge has been found to form in this system. While the cause of the sludge is not completely understood, its formation is believed to take place in passage 28 which is has a gap of only 1.5 mm. However, it may be that the sludge forms in other areas.
[0032] Attempts were made to stop the sludge formation, by plating the surfaces of electrode 18 with fluorosilicones. However, these attempts were only partially successful. Applicants discovered that some fluorosurfactants were more effective than fluorosilicones, while others either did not adhere to the surfaces for extended periods of time or were not overly effective in reducing the formation of sludge, anionic fluorosurfactants worked best. All of the anionic fluorosurfactants were effective, with some of them performing better at sludge reduction than fluorosilicone, the coating material previously thought to perform best.
[0033] In exemplary embodiments of the invention, the following fluorosurfactants gave the best results:
[0034] A-Zonyl® UR, made by DuPont and comprising a surfactant of the form (RfCH 2 CH 2 O) x P(O)(OH) y , where Rf=F(CF 2 CF 2 ) z ; x=1 or 2; y=2 or 1; x+y=3; z=1 to about 7.
[0035] B-Zonyl® FSA, made by DuPont and comprising a surfactant of the form RfCH 2 CH 2 SCH 2 CH 2 CO 2 Li, where Rf=F(CF 2 CF 2 ) x and x=1 to about 9.
[0036] C-Zonyl® FSP, made by DuPont and comprising a surfactant of the form (RfCH 2 CH 2 O) x PO(ONH 4 ) y , where Rf=F(CF 2 CF 2 ) z ; x=1 or 2; y=2 or 1; x+y=3 and z=1 to about 7.
[0037] D.-Zonyl® FSE, made by DuPont and comprising a surfactant of the form (RfCH 2 CH 2 O) x PO(ONH 4 ) y where Rf=F(CF 2 CF 2 ) z where x=1 or 2; y=2 or 1; and z=1 to about 7; x+y=3.
[0038] Other anionic Zonyls were not tested. In preliminary testing ionic Zonyls were found not to have the same effect as the anionic Zonyls. Ionic Zonyls were found to decay relatively quickly with time (as indicated in the above referenced WO 90/05941), and therefore they do not exhibit the sustainable prevention of sludge which has been surprisingly found for the anionic species.
[0039] In a first example of the use of the fluorosurfactant coating, Zonyl® UR is dissolved in warm (40° C.) isopropyl alcohol to form a 2% solids solution. The solution is stirred, for example, with a magnetic stirrer for 30 minutes and then cooled to room temperature and filtered. The part is then coated either by dip coating or spray coating.
[0040] In the dip coating method, the part is cleaned and then immersed in the solution, at room temperature, for 1 minute. The part was then removed from the solution at a constant speed, to aid in the formation of a uniform layer. The part is air dried for 15 minutes at room temperature. It is believed that during the immersion, the fluorosurfactant bonds to the metal electrodes to form a (calculated) thickness (after drying) of 0.05-0.1 micron layer of dry surfactant.
[0041] In the spray coating method, the part is cleaned and the solution is sprayed at the part from a distance large enough so that the spray is uniform over the part, for instance 15 cm. The spraying operation is from top to bottom and the part is dried for two minutes. The part is then sprayed from bottom to top at a somewhat larger distance (20 cm) from bottom to top. This process results in a uniform layer of dried material. The part is dried for 30 minutes at room temperature. The dry coating layer thickness is between 0.05 and 0.1 microns thick.
[0042] In a second example, Zonyl® FSP is diluted with isopropyl alcohol to form a 1% solids solution. The solution is stirred, for example, with a magnetic stirrer for 30 minutes and then cooled to room temperature and filtered. Coating is performed in either the dip or spray methods described for the first example.
[0043] Utilizing either method, the coating is believed to have more than 50% by weight of surfactant material and may have 80, 90 or even 99% or more by weight of the surfactant.
[0044] While the layer in the above examples is between 0.05 and 0.1 micrometers thick, other thicknesses, such as 0.1 to 1 or 2 micrometers are believed to work equally well. Intermediate, thicker or even thinner layers may also work well.
[0045] While not wanting to be bound to any particular theory applicants believe that the anionic fluorosurfactants achieve lasting prevention of sludge while the ionic surfactants do not for one or both of the following reasons:
[0046] 1—The anions form a chemical anchor to the metal surface, which is generally aluminum.
[0047] 2—The anions develop a repelling anionic surface on top of the aluminum surface. It should be understood that the toner is generally charged to a negative voltage.
[0048] While single surfactants have been used in the above examples, mixtures of suitable surfactants are also believed to be useful in the practice of the present invention.
[0049] The present invention has been described using non-limiting detailed descriptions of exemplary embodiments thereof that are provided by way of example and that are not intended to limit the scope of the invention. Variations of embodiments of the invention, including combinations of features from the various embodiments, use of other toner materials etc., will occur to persons of the art. The scope of the invention is thus limited only by the scope of the claims. The terms “comprise,” “include,” “have” or their conjugates, in the claims, mean “including but not necessarily limited to”. | A liquid toner imaging system having at least one metal product, having a coating on at least a portion thereof, the coating having a thickness of between about 0.1 and about 2 microns thereon, said coating comprising an anionic fluorosurfactant, said coating being in contact with liquid toner therein. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to continuous curb laying machines and methods therefor, more particularly, to such machines and methods wherein pieces of expansion joint material may be inserted at intervals into the cast green concrete curb without stopping the apparatus, and it is an object of the invention to provide improved apparatus and methods of this nature.
Continuous curb laying machines are known to the art. Concrete curbing is poured or cast, in a relatively stiff consistency so that it will retain its shape without significantly slumping after the slip form has passed over it. Typically, in the past, expansion joints have been formed in ribbons, or lines, of poured, or cast concrete curbing by hand operations. That is to say, after the concrete curbing has been poured, a workman with a trowel, or similar tool forms a slot in the concrete and inserts a piece of expansion joint material which is essentially a relatively stiff felt board. After the joint material has been inserted, the workman backfills the space on each side thereof with concrete from the original slot formation or from a supply that he may have at hand. In any event, the concrete on each side of the joint material must be smoothed and curved to fit the outline of the curbing in order for the job to appear finished and to have been correctly made. Not only in this process relatively tedious and expensive, but is it time consuming and it requires careful work.
It is also known to the prior art to have a machine for inserting an expansion joint into a road surface that has been cast, or poured, from concrete or the like. Because of the relatively wide expanse of road surfaces, machines for inserting expansion joint material or pieces have been of equal length, and thus, the apparatus for insertion of the joint material has been bulky and complicated. Schemes for supporting the expansion joint material during the insertion process have been complicated and have not lent themselves to utilization in curb forming apparatus because the curbing, ordinarily, has a shape different from straight or flat.
Certain expansion joint inserting machinery is known to the art. Reference may be made to U.S. Pat. Nos. 2,014,894 Heltzel, 3,200,482 Brown, 3,246,390 Brown, 3,335,647 Thorp, Jr., 3,473,450 Koch. In each of these patents road surfaces are poured first and a second machine is utilized to insert the expansion joint. In each case a slot or channel is first formed or the concrete previously treated at the place of insertion. Clearly these solutions are cumbersome and relatively inefficient when compared to the applicant's continuous apparatus and method.
SUMMARY OF THE INVENTION
It is an object of the invention to provide, in apparatus and methods for continuously laying curbing, an improved apparatus and method for inserting expansion joint material as part of a continuous process.
It is a further object of the invention to provide improved concrete curb forming machines including means for automatically inserting expansion joint material that will overcome the defects of the prior art.
In carrying out the invention according to one form, there is provided apparatus for inserting a piece of expansion joint material into a strip of cast material having a predetermined shape comprising a slip form of predetermined length and strip shape underneath which strip forming material is to be cast, a slot in the slip form, blade means adapted to move through the slot perpendicularly to the line of the slip form and through any green cast strip forming material, a template attached to one side of the blade for movement therewith, the template having a pushing surface whose outline conforms to the strip surface shape, and means for moving the blade into and out of the slot in the slip form.
In a preferred form of the invention, the template pushing surface outline would have the same image, or conforming, image shape of the strip curb or strip surface. The blade and template and the associated piece of expansion joint material may be forced, or rammed, into the green curbing strip by fluid pressure actuated pistons. Specifically, in some instances, air pressure may be used. The invention also contemplates the method of inserting pieces of expansion joint material into a continuously cast strip of concrete curbing which comprises the steps of providing a slip form of curb surface shape, continuously casting a concrete strip underneath the slip form, providing a slot forming blade to move vertically into the green concrete strip and providing a piece of expansion joint material on the downstream side of the blade on each movement thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete description of the invention reference may now be had to the accompanying drawings in which:
FIG. 1 is an outline view of a machine according to the invention showing the curbing at the left side;
FIG. 2 is a partial end view of the machine shown in FIG. 1;
FIG. 3 is a fragmentary view, in perspective, of certain operating components in operating position;
FIG. 4 is a fragmentary view, from a different perspective, of some of the components shown in FIG. 3;
FIG. 5 is a fragmentary end view, in perspective, of the machine shown in FIGS. 1 and 2;
FIG. 6 is a side view taken in the direction of the arrows 6--6 of FIG. 5;
FIG. 7 is a view similar to FIG. 6 with certain parts in a different operating position; and
FIG. 8 is a fragmentary diagrammatic front view of certain operating parts taken along the lines 8--8 of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, there is shown a continuous curb laying machine 10 embodying the expansion joint inserting mechanism and method of the invention shown generally by the reference character 11 in FIGS. 1 and 2.
The machine 10 moves in the direction of the arrow A under the influence of power-driven caterpillar treads 12. In so doing, the machine deposits pre-mixed concrete underneath a slip form 13, referred to in the trade as a mule, from a hopper 14 into which the concrete has been deposited from a spiral conveyor 15 to which the green concrete is supplied through a chute 16 by any concrete mix vehicle (not shown, but as is well understood in this art).
As the machine 10 moves forwardly in the direction of the arrow A, the curb 17 is formed by taking the shape of the undersurface of the mule, or slip form 13, which is in the shape of the curb, or conforms to it. In a sense, the shape of the mule, or slip form, is the reversed image of the curb itself. The machine is guided very accurately along a line determined by a guide line 18 disposed in the proper location and held by supports 19 as is well understood and which form no part of the present invention.
The machine 10 moves forwardly under power supplied from any convenient engine aboard such as, for example, diesel engines that are not shown and do not form part of the invention. The machine, however, can be accurately controlled to move forwardly at a steady pace so that the curbing 17 is laid down at a uniform rate and with uniform quality.
Referring to FIG. 2, two of the caterpillar treads 12 are shown as well as support members 21 resting thereon. It is understood that the remaining portion of the machine 10 would be disposed atop that portion shown in FIG. 2, but the detail of the machine is not necessary to the explanation of the invention and it is not shown in FIG. 2. Nevertheless, attached to the support, or frame work, 21 is an appropriate arm 22 and links 23 and 23A which support the curb laying apparatus 11 including the slip form or mule 13 and the green concrete supply mechanism including the hopper 14, the conveyor 15, the chute 16 and the expansion joint inserting blade mechanism 24.
The machine 10 moves at a relatively slow rate, the length of the mule 13 between the point where the concrete is fed into it at chute 14 and the exit end of the machine at a point defined by the reference character 25 (slightly beyond the blade inserting mechanism 24), being such that the curb will retain its desired shape as seen at the reference character 17, for example. For this to occur, the concrete has to be of the relatively quick set variety.
However, while the concrete has assumed its final shape and retains it, the concrete is still green so that the inserter blade and the expansion joint felt material can be rammed into it as will be described.
Referring more particularly to FIGS. 3-6, there is shown in fragmentary form the inserting blade machanism 24 and a piece 26 of expansion joint material, or felt. The finished curb 17 also is shown with a piece of curb expansion joint material 26 in place therein after having been rammed there into by the mechanism to be described.
The expansion joint inserting mechanism 24 includes a blade 27 disposed to move and guides 28. The blade is driveable downwardly and upwardly by means of connecting rods 29 driven by air cylinders 31 supplied from a tank 32 of air under pressure through appropriately operating air valves 33 which may be electrically controlled, as is well understood. All of the apparatus described for actuating the blade 27 is, of course, supported by the arm 22, the links 23 and 23A and any necessary other mechanism not shown, as is well understood.
A slot 34 (FIG. 3) is disposed between the forward and rearward portions of the mule 13 and provides a space for movement, downwardly and upwardly, of the blade 27.
Attached to the rearward, or downstream, side of the blade 27 by any suitable means such as, for example, welding, is a template, or inserting plate, 35 which has a shape conforming to that of the curb. Thus, it is adapted to receive the piece 26 of expansion joint material as may be visualized more clearly in FIGS. 2 and 4. The edge 36 of the felt piece 26 conforms to and interfits with the edge 37 of the template 35. The expansion joint piece 26 is of such dimensions as to be readily disposed along the edge 37 of the template 35 and is disposed between the facing edges of the guides 28. The blade 27 can move downwardly in the slots 28A of the guides 28 without any interference from the expansion piece. The blade 27 has a lower edge 38 that may be sharpened as shown for easier insertion into the concrete surface and thus to enable the dislodgement in the concrete mass of any rocks, gravel or the like.
When the expansion joint piece 26 is placed into position against the blade 27, the lower edge 39 thereof preferably is disposed slightly above the sharpened lower edge 38 of the blade 27. Thus, when the blade 27 is rammed downwardly the edge 28 can start a groove or kerf the continuation of which, as the blade 27 moves downwardly, enables the expansion joint piece 26 to move into the groove thus formed, thereby disposing the expansion joint piece into the resulting kerf in the partially cured concrete. When the blade 27 is retracted the expansion joint piece 26 remains in place, being held there by friction with concrete. The placement of the pieces 26 and the operation of this structure will be described more fully.
In operation of the machine 10, the machine moves forwardly in the direction of the arrow A at a specified velocity which might be, for example, ten to twenty-five feet per minute, and is continuous on the prepared roadway surface. During this movement, the concrete is supplied to the chute 14 and thus to the mule, or slip form, 13 from the conveying apparatus described and the concrete curbing is formed by the extrusion of the concrete into the slip form. At the appropriate places indicated by markers on the edge of the roadway surface, for example, or otherwise, without stopping the machine the air pressure is supplied, through suitable valves, to the cylinders 31 thereby ramming the blade 27 downwardly through the slot 34 as may be seen in FIG. 3, a piece of expansion joint felt 26 previously having been placed in position against the template 35. Thus as the blade 27 moves downwardly in the guillotine like slots 28A in the guides 28 the expansion joint piece 26 is forced into, or rammed into, the green concrete. As indicated, when the blade 27 is retracted by the reverse movement of the connecting rods 29, the expansion joint piece 26 remains in place. As may be seen in FIG. 3, the expansion joint piece 26 is in place between two adjacent sections of the concrete curbing and the curbing retains its shape. The distance of the slot 34 from the end 13A of the mule in a typical case may be about six feet.
With the insertion of the expansion joint piece 26 as described it has been found that the resulting joint is smooth and does not need any patching to provide an appropriate finished appearance. In other words, the ramming into the concrete of the expansion joint piece does not mar the surface of the curb in any significant way.
The expansion joint piece 26 may have any desired thickness, for example, three-eighths to one-half inch and is a relatively rigid piece of material in order to perform the function of being an expansion joint. This stiffness renders it adequate for ramming it through the concrete curb in the setting process.
As has been indicated the sharpened edge 38 enables the blade 27 to move into the concrete relatively easily, but the sharpened edge on the upstream side moves away any pebbles or gravel that tend to block the downward movement of the blade.
In the operation of the device it has been found that the cylinders 31 may be typical four inch by seventeen inch devices operating on an air pressure of about one hundred pounds per square inch.
Additional structure of the invention may now be described: Following the exit 25 of the slip form proper 13 (mule) just beyond the slot 34, the slip form terminates in a nose member 41 of the same cross-sectional shape as the mule. Such a nose member is sometimes referred to in the trade as a fresno. For any adjustability as may be necessary, the nose member 41 (fresno) is pivotally attached by a bolt 42, for example, which passes through an opening in a bracket 43 welded to the end of slip form 13. While not shown, there would be, ordinarily, two brackets 43, one on each side of the nose member 41. In addition, the upper portion of nose member 41 is attached by means of turn buckle links 44 to the vertical members 28. The adjustability provided by the links 44 enables the nose member 41 to assume the same line as that of the slip form. In addition, the presence of the nose member 41 provides any additional smoothing of the cast concrete with the expansion material 26 inserted therein as may be needed as a result of the ramming into the concrete of the inserting blade and the insertion joint material.
An inventory of expansion joint pieces 26 is provided as shown in FIGS. 5, 6 and 7 along with certain additional structure. As shown in these Figures the inventory of expansion joint pieces 26 is held on a tray 45 which is welded to the upright members 28. Welded, for example, to the ends of tray 45 is a pair of upright members 46 between which extends a shaft 47. Midway between the uprights 46 on shaft 47 there is a lever 48, one arm 49 of which is adapted to support a weight 51 and the other arm 52 of which bears against a plate 53, which in turn bears against the outermost of the pieces 26. As may be understood from FIGS. 5, 6 and 7, the weight 51 urges the insertion pieces 26 inwardly to be received, at the appropriate time, against the blade member 27.
Between the base of the tray 45 and the upper surface of the rearward end of the slip form 13 is a guide plate 54. The lower edge 55 of the guide plate conforms to and bears against the cooperating surface of the slip form 13 and may be welded thereto. The upper edge 56 of the guide plate 54 extends relatively straight across and, as indicated above, is welded to the lower surface of the tray 45 and forms therewith the surface along which the insertion members 26 are moved into position. The interior surface of the guide plate 54 adjacent the slots 34 conforms to the line 41A of the nose member 41 to form an in line director for the movement of the expansion joint piece 26 as may be visualized by comparing FIGS. 6 and 7. Thus, as the expansion piece 26 is being moved downwardly, the body thereof is squeezed between the interior surface of the guide plate 54 and the adjacent surface of the blade 27 to compress the expansion material as it moves into the green concrete. When all of the piece 26 has been inserted (FIG. 7), its fibrous nature causes it to expand due to the release of the compression it has gone through. Hence, the material thereupon expands underneath the surface of the guide plate and the slip form and does not have as great a tendency to be retracted along with the blade 27 on its retractive stroke.
Disposed atop the straight upper edge 35A of the template 35 is a stop plate 57 which may be welded to the cooperating edge of the template. As the template 35 moves downwardly, as can be seen in comparing FIGS. 5 and 7, the next adjacent insertion member 26 will tend to be moved into position by the action of weight 51 and the associated mechanism. The stop plate 57, however, moves into position inasmuch as this member is directly in line above the template 35 and consequently, the next in line insertion member 26 moves only until it is up against the stop plate 57 at which point it stops its movement. When, however, the inserting blade 27 has moved to its upper position as shown in FIG. 6 the stop plate 57 has moved out of the way and the next in line insertion member 26 moves into position for the coming insertion stroke. Closing the upper portion of the tray 45 is a top member 58 which lies just above the inventory of expansion members 26 and thus prevents these members from moving upwardly out of position when the blade 26 is moved in its upward stroke.
In FIG. 8 the relative positions of the operating members may be visualized before the insertion stroke has taken place, which is to say the view would be taken in the direction of lines 8--8 of FIG. 6. Thus in FIG. 8, there may be visualized the slip form 13 in sectional view, the guide plate 54, the insertion blade 13, the blade 27, the insertion member, or template, 35 and the stop plate 57 all arranged for the moving parts to move downwardly in the vertical guides 38. The corresponding view to FIG. 8 for the parts as shown in FIG. 7 would differ essentially only in that the blade 13 and the template 35 would exist in the downward or lowermost position.
It will be noted that the connecting rods 29 of the operating cylinders 31 are connected to the inserting blade 27 by pivotal connections 59 to relatively short arms 61 extending forwardly of the inserting blade. The length of the arms 61 forms a lever arm separating the blade 27 from the line of travel of the rods 29 so that as the rods 29 move down the blade 27 is tended to pivot clockwise as may be visualized best in FIG. 7. This clockwise tendency of the blade 27 tends to urge the expansion piece 26 clockwise which is to say against the concrete mass into which it is being inserted. This causes the piece 26 to be compressed against the mass of concrete. Hence, when the rods 29 move upwardly to retract the blade 27, the same lever arm 61 tends to pivot the blade 27 counter-clockwise which is to say away from adjacent surface of the expansion joint piece 26. Accordingly, the piece 26 tends to be released from the blade 27 and tends to remain, and in fact does remain, securely within the slot formed in the green concrete. Thus, in addition to the fact that the expansion piece 26 is first compressed and expands under the surface of the slip form, the blade 27 is rotated away from the expansion piece. The two effects combine to avoid removal of the expansion joint piece 26.
Referring to FIG. 3, there are shown two screw type stops 62 disposed in a cross-member 63 supported on, and attached to, the forward edge of the slip form. The stops 62 are adjusted to abut against the blocks 64 which hold the pivots 59. In this manner the extent of the downward travel of the blade 27 is adjusted to the desired value.
The rods 29 are caused to move upwardly by appropriate action of the valve to admit air into the cylinders 31 as is well understood. The valves may be controlled electrically or mechanically as desired without involving the present invention.
As may be seen in the Figures, the left side 13A of the slip form is higher than the right side 133. This is to conform the shape of curb 17 to the road surface which ordinarily has a crown, or slight angularity.
While one form of apparatus and method are shown, it will be clear that other forms may be devised without departing from the scope of the disclosure. | The continuously extruding curb forming machine for roads, for example, may be equipped with a downwardly moving sharpened blade for use in the insertion of an expansion joint piece at appropriate intervals into the curb without stopping the operation of the machine while the expansion joint piece is inserted. The expansion joint piece may be well known felt material for this purpose and the inserting blade has a template attached thereto the surface of which conforms to the surface of the curb and thus to the surface of the expansion joint piece. As the blade moves into the partially cured concrete, the template forces the joint piece into the same concrete. | 4 |
This is a division of application Ser. No. 06/432,257, filed Dec. 26, 1982, now U.S. Pat. No. 4,496,378.
This invention relates to a method of assembling accmulator dehydrators.
BACKGROUND OF THE INVENTION
In an automotive air-conditioning system, the compressor pumps heat-laden refrigerant from the evaporator, and compresses the refrigerant, sending it, under high pressure, to the condenser as a superheated vapor. Since the high pressure vapor delivered to the condenser is much hotter than the surrounding air, it gives up its heat to the outside air flowing through the condenser fins.
As the refrigerant vapor gives up its heat, it changes to a liquid. The condensed liquid refrigerant is filtered, dried and temporarily stored under pressure, in the receiver-drier, also known as the "accumulator dehydrator", until it is needed by the evaporator.
Liquid refrigerant is metered from the condenser into the evaporator by an orifice tube which controls the flow of refrigerant in the conditioning system. The orifice tube floods the evaporator with liquid refrigerant. In so doing, the liquid refrigerant picks up heat from the warm air passing through the fins of the evaporator. The warm liquid refrigerant boils into the accumulator dehydrator. The compressor then transmits the warm dehydrated vapor to the condensor for dissipation.
The present invention is concerned particularly with the method of making an accumulator dehydrator or receiver-drier, which, as stated, is a part of the system that is used to store refrigerant. It is located in the low-pressure side of the air-conditioning system and for the most part, contains liquid refrigerant.
The accumulator dehydrator usually consists of a cylindrical metal can with inlet and outlet fittings and, in most cases a a slight glass. It may be divided into two parts: the receiver and the drier.
The accumulator section of the tank or can is a storage compartment to accept the proper amount of excess refrigerant the system requires to insure operation. It is the function of the accumulator section to insure that a steady flow of vapor refrigerant is supplied to the compressor.
The dehydrator section of the tank or can is simply a bag of dessicant, such as molecular sieve, that is capable of absorbing and holding a small quantity of moisture.
A screen is placed in the dehydrator section to catch and hold any trash that may be in the system and prevent its circulation. Through this screen is not serviceable, the cleaned orifice tube that may be cleaned or replaced if necessary.
SUMMARY OF THE INVENTION
The method of assembling an accumulator dehydrator in accordance with the present invention comprises providing a dehydrator cap having an opening through it, providing a fitting having a portion which is smaller than the opening, providing a deflector having a body and an arcuate flange extending from it, then placing the fitting on the outside of the cap and inserting the portion of it into the opening in the cap, placing the deflector on the inside of the cap and inserting the flange into the opening, in exterior or surrounding relation to the fitting, and then welding the fitting to the cap.
It is an object of the present invention to provide an economical and reliable method of assembling an accumulator dehydrator, comprising a cap, a fitting and a deflector.
Another object of the present invention is the provision of such a method which will enable the fabrication of an accumulator dehydrator from readily available parts, and using readily available equipment and methods.
These and other objects and features of the invention will be apparent from the detailed description, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a preferred form of the accumulator dehydrator, embodying the invention;
FIG. 2 is a side elevational view of the accumulator dehydrator, as viewed from the lower side of FIG. 1;
FIG. 3 is a cross-sectional view of the accumulator dehydrator taken on the line 3--3 of FIG. 1;
FIG. 4 is a cross-sectional view, taken on the line 4--4 of FIG. 2;
FIG. 5 is a fragmentary cross-sectional view, taken on the line 5--5 of FIG. 1;
FIG. 6 is a fragmentary cross-sectional view, taken on the line 6--6 of FIG. 1;
FIG. 7 is a perspective or isometric view of the deflector of the accumulator dehydrator;
FIG. 8 is an end elevational view of the deflector of FIG. 7;
FIG. 9 is a plan view of the deflector of FIG. 7;
FIG. 10 is a cross-sectional view, taken on the line 10--10 of FIG. 9, and
FIG. 11 is a view similar to FIG. 1, but showing that the deflector on the inlet port will operate regardless of the position of the outlet port.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring more particularly to FIGS. 1 to 10 inclusive of the drawings, the accumulator dehydrator includes an accumulator cap 1, of generally cylindrical shape, having a dome-like upper end 2, and a series of circumferentially-spaced flats 3, 4 and 5 in the cylindrical wall of the cap. The cap is open at the bottom, as at 6.
The cylindrical side wall of the cap 1 is provided with openings 7, 8 and 9, the opening 7 extending through the flat 3, the opening 8 extending through the flat 4, and the opening 9 extending through the flat 5.
The accumulator dehydrator further includes a bottom cap 10, also of generally cylindrical shape, having a dome-like lower end 11, and open at its upper end, as at 12. The bottom cap 10 fits telescopically into the cap 1, and is welded to the cap 1, as at 13.
Secured to the cap 1, in axial alignment with the opening 7 in the flat 3 is a hex-headed fitting 14, which is welded, as at 15, and has a portion thereof extending through the opening 7. The fitting 14 is an inlet fitting, which is adapted to receive fluid from the evaporator (not shown) of the automotive air-conditioning system, and to be discharged into the accumulator dehydrator.
Secured to the cap 1 in axial alignment with the opening 8 in the flat 4 is a fitting 16, which is welded, as at 17, to the flat 4, and has a portion thereof extending through the opening 8. The fitting 16 is an outlet fitting, which is adapted to receive fluid from the accumulator dehydrator to the condenser (not shown) of the automotive air-conditioning system and returned to the evaporator.
Secured to the cap 1, in axial alignment with the opening 9 in the flat 5, is a valve core 18 of the Schrader type, which is welded, as at 19, to the flat 5, and extends through the opening 9. The core 18 is part of a charge fitting or valve through which the system is charged with refrigerant.
The accumulator dehydrator is provided interiorly thereof with a U-shaped tube 20 comprising a bight portion 21 and a pair of upstanding leg portions 22 and 23. The bight portion 21 has a bleed opening or port 24 through the bottom side thereof which is located adjacent to and faces the closed bottom 11 of the bottom cap 10, while the leg portions 22 and 23 are sized to extend substantially the height of the accumulator dehydrator. In addition, there is provided a cylindrical screen assembly 24 which is received about the bight portion 21 and serves to screen out particles in the collected liquid to prevent clogging of the bleed port 24.
The leg portion 22 has an open end 26 located adjacent the closed upper end of the cap 1. The other tube leg 23 has a right angle bend to its open end 27 which is adapted to be received in and permanently connected by swaging to the outlet fitting 16 thus providing for permanent attachment between the tube and the cap 1.
The accumulator dehydrator is further provided with a hollow porous dessicant container or molecular sieve 28, which is adapted to be received in the lower end of the accumulator dehydrator. The dessicant container is preferably made in the form of two bags or halves, 29 and 30, which as best seen is FIG. 3, are heated-sealed to each other, and are joined by a web 31, which encircles the screen 25. Each bag contains dessicant 32, such for example as molecular sieve.
An important feature of the invention resides in the provision of a deflector for the accumulator dehydrator, which is of unique design or construction, and which can be assembled with upper cap in a unique manner, without the aid of extraneous fasteners.
The deflector is clearly illustrated in FIGS. 3, 4, 6, 7, 8, 9 and 10.
The deflector is preferably made in one piece as a metal stamping, stamped or formed to provide a flat elongated body 33 having downturned flanges 34 and 35, at its side edges, and an arcuate flange 36 at one end. As seen in FIG. 7, the flange 36 extends inwardly beyond the edges of the flanges 34 and 35, to thereby form a tenon whereby the deflector may be attached to the cap 1.
In assembling the deflector with the cap 1 and the fitting 14, the flange 26 is inserted between the hole 7 in the cap, and the portion of the fitting 14 which extends into the hole 7 acts not only to hold the deflector in the position shown in FIG. 3, but also to prevent the deflector from being rotated about the axis of the hole 7. With the parts thus assembled, the weld material 15 is applied, and flows between the parts to permanently hold the deflector in its operative position, as shown in FIGS. 3 and 4.
The incoming vaporous refrigerant is caused to impinge against the body 33 of the deflector to encourage separation of the liquid components (refrigerant, oil, water) and cause same to be deposited in the bottom of the accumulator dehydrator.
With the dessicant (molecular sieve) stored in the dessicant bags, the deposited water is absorbed and retained thereby while the deposited liquid refrigerant and oil is eventually aspirated through the bleed port 24 in vaporous from into bight 21 of the tube 20, where it passes along with the vaporous refrigerant already flowing therethrough and then out the outlet fitting 16 into the compressor (not shown) of the air-conditioning system.
In FIG. 11 of the drawings, a modification is shown, in which the inlet and outlet fittings are disposed at diametrically-opposite sides of the cap. This accumulator dehydrator is basically the same on the inside and bottom half as that herein above described, the only difference being the location of the inlet and outlet fittings to fit different models of General Motors cars. The fittings on the accumulator dehydrators are located depending on how the accumulator is mounted on the car and the bend configuration of the tube and hose assembly that is secured to the accumulator. The accumulator serves the same purpose irrespective of the model car or the fitting location.
While this invention has been described as having a preferred method, it will be understood that it is capable of further modification. This application is, therefore, intended to cover any variations, uses, or adaptations of the invention following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art of which this invention pertains, as may be applied to the essential features hereinbefore set forth and fall within the limits of the appended claims. | A method for assembling an accumulator dehydrator comprising a cap, a fitting and a deflector, the deflector having a body and an arcuate flange extending from it, the method comprising providing a cap having an opening through it, the fitting having a portion smaller than the opening, the steps including placing the fitting on the outside of the cap and inserting the portion of it into the opening, placing the deflector on the inside of the cap and inserting the flange of it into the opening, exteriorly of the fitting, and welding the fitting to the cap. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from provisional application Ser. No. 60/226,295, filed Aug. 21, 2000, entitled “REPAIR OF COATINGS AND SURFACES USING REACTIVE METALS COATING PROCESSES” which is incorporated herein, in its entirety, by reference.
BACKGROUND OF THE INVENTION
[0002] This invention pertains to the repair of parts comprising metals, and surfaces and coatings of said parts using reactive metals coating processes. Coating and surface repair fall under U.S. Patent Class 427 (COATING PROCESSES), Subclass 140 (Processes directed to the restoration or repair of coatings or surfaces of objects). Surface treatments via reactive metal coating processes fall under U.S. Patent Class 148 (METAL TREATMENT), Class Definition C ( . . . processes of reactive coating of metal wherein an externally supplied carburizing or nitriding agent is combined with the metal substrate to produce a carburized or nitridized or carbonitrided coating thereon or a uniformly carburized, nitrided, or carbonitrided metal alloy containing a metal element from said substrate) and Class Definition D ( . . . processes of reactive coating of metal wherein an externally supplied agent combines with the metal substrate to produce a coating thereon which contains at least one element from said metal substrate). This invention is applicable in maintenance and restoration of parts in many industries including, but not limited to, aviation and space industries.
[0003] Coatings and Surface Treatments
[0004] Various processes are well-known for providing coatings or modified surfaces on metals to protect them from effects such as wear, erosion, and corrosion. Such processes include chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma spray, and reactive coating (boronizing, carburizing, nitridizing, carbonitridizing, etc.). For instance, U.S. Pat. No. 5,272,014 (Leyendecker) teaches a wear-resistant CVD coating for substrates such as forming or cutting tools. U.S. Pat. No. 5,656,364 (Rickerby) and U.S. Pat. No. 5,702,829 (Paidassi) teach multiple-layer erosion-resistant PVD coatings for substrates such as gas turbine engine compressor or turbine blades. U.S. Pat. No. 4,850,794 (Reynolds, Jr.) teaches solution-bath and gas nitriding to enhance the wear-resistance of steam turbine components. U.S. Pat. No. 4,588,450 (Purohit) teaches nitriding of nickel-based super alloys including inconel to improve their creep strength, fatigue strength, and resistance to oxidation. U.S. Pat. No. 6,129,988 (Vance, et al.) teaches gas nitriding of metallic bond coatings for thermal barrier coating systems. Nitriding of metallic bond coatings enhances oxidation resistance thereby prolonging the adherence of ceramic thermal barrier coatings applied thereon. CVD, PVD and plasma spray processes generally involve deposition of additional material on the surface of a substrate. Reactive coating processes generally involve incorporation or dispersion of additional chemical constituents into the existing lattice structure of a metal substrate.
[0005] Functionally Gradient Surfaces
[0006] Reactive coating processes are known for producing treated surfaces with chemical compositions that vary as a function of depth, also known as functionally gradient surfaces. For instance, surfaces produced via nitriding consist of a hard nitride layer above a nitrogen-containing diffusion zone, with nitrogen content gradually decreasing deeper into the substrate material. Richter discusses a plasma nitriding process for producing functionally gradient surfaces on stainless steel and aluminum alloys (“Nitriding of Stainless Steel and Aluminum Alloys by Plasma Immersion Ion Implantation”, Surface and Coatings Technology, Vol. 128-129, 2000, pp. 21-27). U.S. Pat. No. 4,762,756 (Bergmann) teaches a plasma nitriding process that is enhanced using arc discharge, whereby functionally gradient surfaces are produced on metals including stainless steel and titanium. Meletis discusses an enhanced plasma nitriding process for producing functionally gradient surfaces on titanium (“Characteristics of DLC Films and Duplex Plasma Nitriding/DLC Coating Treatments”, Surface and Coatings Technology, Vol. 73, 1995, pp. 39-45). This enhanced nitriding process is also taught in expired U.S. Pat. No. 4,460,415 (Korhonen, issued Jul. 17, 1984) and U.S. Pat. No. 5,334,264 (Meletis, issued Aug. 2, 1994). U.S. Pat. No. 4,568,396 (Vardiman) teaches a carburizing method via carbon ion implantation wherein carbon content of the treated surface varies as a function of depth. PVD and CVD processes are better-known for producing coatings of uniform composition as a function of depth (monolayers), but can also be adapted to produce functionally gradient surfaces. For example, U.S. Pat. No. 5,989,397 (Laube) teaches a method and apparatus for producing deposited surfaces with depth-varying compositions of titanium, carbon, and nitrogen.
[0007] Enhanced Plasma Nitriding
[0008] A review of enhanced nitriding processes is presented by Czerwiec et al (“Low-pressure, high-density plasma nitriding: mechanisms, technology and results”, Surface and Coatings Technology, Vol. 108-109, 1998, pp. 182-190). These processes can be classified under the following four categories: Thermionically assisted d.c. triode (TAT); plasma immersion ion implantation (PIII) or plasma source ion implantation (PSII); electron cyclotron resonance (ECR) systems; and thermionic arc discharge (TAD). A version of the TAT enhanced plasma nitriding method and apparatus presented by Meletis in U.S. Pat. No. 5,334,264 is previously taught by expired U.S. Pat. No. 4,460,415 (Korhonen), and also by earlier references including Matthews and Teer (“Characteristics of a Thermionically Assisted Triode Ion-Plating System”, Thin Solid Films, Vol. 80, 1981, pp. 41-48), Korhonen and Sirvio (“A New Low Pressure Plasma Nitriding Method”, Thin Solid Films, Vol. 96, 1982, pp. 103-108), Korhonen et al (“Plasma Nitriding and Ion Plating With an Intensified Glow Discharge”, Thin Solid Films, Vol. 107, 1983, pp. 387-394), Fancey and Matthews (“Some Fundamental Aspects of Glow Discharges in Plasma-Assisted Processes”, Surface and Coatings Technology, Vol. 33, 1987, pp. 17-29), Ahmed (“Ion Plating Technology, Developments and Applications”, John Wiley and Sons, New York, 1987, pp. 68-70), Fancy and Matthews (“Process Effects in Ion Plating”, Vacuum, Vol. 41, No. 7-9, 1990, pp. 2196-2200), and Leyland et al (“Enhanced Plasma Nitriding at Low Pressures: A Comparative Study of D.C. and R.F. Techniques”, Surface and Coatings Technology, Vol. 41, 1990, pp. 295-304. Furthermore, Molarius et al teaches that the process of U.S. Pat. No. 4,460,415 (Korhonen) can be used to treat titanium (“Ion Nitriding of Steel and Titanium at Low Pressures”, 4th Int. Congress on Heat Treatment of Materials. Jun. 3-7, 1985. Berlin (West), Proceedings, Vol I, p. 625-643. Härterei-Technische Mitteilungen 4(1986)6, 391-398.). These references establish prior art that pre-dates the filing of the Meletis Patent by 2 to 10 years. None of these references is cited in the Meletis Patent. U.S. Pat. No. 5,334,264 therefore teaches very little that was not previously taught by prior art.
[0009] Performance of Functionally Gradient Surfaces
[0010] Functionally gradient surfaces are known to have superior wear and erosion properties compared to monolayer coatings. Voevodin presents results of scratch tests for multiple-layer titanium, titanium carbide, and diamond-like carbon (DLC) surfaces prepared using the process of U.S. Pat. No. 5,989,397 (“Design of a Ti/TiC/DLC Functionally Gradient Coating Based on Studies of Structural Transitions in Ti-C Thin Films”, Thin Solid Films, Vol. 298, 1997, pp. 107-115). Meletis presents results of wear tests for functionally gradient, nitrided titanium surfaces (“Characteristics of DLC Films and Duplex Plasma Nitriding/DLC Coating Treatments”, Surface and Coatings Technology, Vol. 73, 1995, pp. 39-45). Gachon presents results of erosion tests for functionally gradient, multiple-layer tungsten carbide coatings (“Study of Sand Particle Erosion of Magnetron Sputtered Multilayer Coatings”, Wear, Vol. 233-235, 1999, pp. 263-274). Gupta presents results showing that PVD multilayer titanium nitride coatings have superior erosion resistance compared to titanium nitride monolayer coatings on turbine engine compressor blades (“Protective Coatings in the Gas Turbine Engine”, Surface and Coatings Technology, Vol. 68/69, 1994, pp. 1-9). Because of their superior performance, functionally graded surfaces are preferred over monolayer coatings. In general, thicker coatings or surface treatments (monolayer or functionally gradient) tend to provide better wear and erosion protection.
[0011] Surface Treatments and Fatigue Strength
[0012] Coating or surface treatment thickness determines not only wear and erosion resistance, but can also affect fatigue strength of the substrate. For instance, previous attempts to plasma nitride titanium and titanium alloys have most often produced surfaces with increased wear resistance, but often reductions in substrate fatigue strength. Morita presents a list of references dating from 1964 to 1996 for which this is true (“Factors Controlling the Fatigue Strength of Nitrided Titanium”, Fatigue & Fracture of Engineering Materials & Structures, Vol. 20, No. 1, 1997, pp. 85-92). Morita also shows the relationship between substrate fatigue strength, substrate grain size, and surface treatment depth (case depth) for nitrided titanium. Morita gas nitrided samples at temperatures from 620 degrees C. to 1200 degrees C. to achieve a range of case depths and grain sizes. Results show that for equivalent grain sizes, the fatigue strength of nitrided titanium with a case depth of 40 micrometers is greater than the fatigue strength of the untreated substrate. When the case depth is increased to 100 micrometers (same grain size), fatigue strength of the nitrided material is significantly decreased compared to the untreated substrate. These results apply over a wide range of grain sizes. The diffusion zone of the nitrided surface appears to help suppress crack propagation in the substrate, but only to a limited degree. The tendency of the 40 micrometer depth case to fracture and initiate substrate crack growth tends to be countered by decreased tendency for slip and dislocations in the diffusion zone. Under a similar level of substrate strain the 100 micrometer case is more likely to fracture, and the diffusion zone is unable to counter the increased tendency for crack growth. Morita's results also indicate that long nitriding times at high temperatures tend to degrade fatigue strength via excessive case thickness and excessive grain growth (e.g., material annealing).
[0013] Degradation of fatigue strength due to thick coatings on turbine engine compressor blades is mentioned by Friedrich (“Improving Turbine Engine Compressor Performance Retention Through Airfoil Coatings”, NASA Lewis Research Center Aircraft Engine Diagnostics, Document ID 19810022661 N (81N31203), January 1981, pp. 109-117) and in U.S. Pat. No. 4,761,346 (Naik). There appears to be a correlation between thick coatings and degradation in fatigue strength. Thicker coatings tend to provide better wear and erosion protection but often at the expense of fatigue strength. These factors must be considered carefully for coatings and surface treatments, particularly in applications where superior fatigue strength is important.
[0014] Surface Damage and Repair
[0015] Despite improved protection of the substrate, monolayer coatings or functionally gradient surfaces will eventually wear, erode, or corrode in-service and the underlying metal substrate can be exposed. In general, damage to coated or treated surfaces is not uniform, and consists of local damage sites surrounded by areas where the coating or surface treatment is intact. This is particularly true in cases where the surface has experienced impact or micro-chipping damage due to erosive service conditions. For instance, Gupta shows localized damage to a titanium nitride coated turbine engine compressor blade (“Protective Coatings in the Gas Turbine Engine”, Surface and Coatings Technology, Vol. 68/69, 1994, pp. 1-9). Once damaged, coated or treated parts must be restored or repaired to reestablish the original level of protection provided to the substrate.
[0016] Damaged areas of some coatings can be cleaned of loose debris and the surface spot-repaired or re-coated. For instance, U.S. Pat. No. 5,958,511 (DeCoursey) teaches a process for spot-repairing conversion coatings such as Alodine (Henkel Surface Technologies, Madison Heights, Mich.—formerly Parker-Amchem). U.S. Pat. No. 3,248,251 (Allen) describes aluminum-filled inorganic phosphate overlay coatings that are used to protect components in turbomachinery. A commercial version of this coating manufactured by Sermatech International Inc. (Limerick, Pa.) is reportedly spot-repairable. U.S. Pat. No. 6,042,880 (Rigney) teaches repair and spot-repair of metallic bond coats used under thermal barrier coatings (TBCs) on turbine blades, wherein the TBC is completely removed to expose the bond coat, then the bond coat spot-repaired. Rigney emphasizes that complete removal of the TBC and bond coat, and simultaneous unintentional removal of substrate is detrimental to blade fatigue life.
[0017] Other more durable coatings including some produced via CVD, PVD, or plasma spray processes are not typically spot-repaired. Usual practice for these coatings is to completely remove all old surface materials, thereby helping to ensure the integrity of the replacement coatings. For instance, U.S. Pat. No. 5,368,444 (Anderson) discusses the strip and re-coat of copper-nickel-indium anti-fretting and anti-wear coatings commonly employed on compressor and turbine blade dovetails. U.S. Pat. No. 5,813,118 (Roedl) and U.S. Pat. No. 6,049,978 (Arnold) describe grit blast and chemical stripping for turbine engine airfoils. U.S. Pat. No. 5,421,517 (Knudson) teaches a waterjet removal process for gas turbine engine components and also aircraft exterior surfaces. U.S. Pat. No. 6,036,995 (Kircher) teaches removal of the surface layer of a metallic coating by first applying a slurry of aluminum in an inorganic binder to the surface of a part coated with the coating, then heating the coated part to melt the aluminum which flows inward into the surface and reacts with the surface to form a brittle aluminide layer, and finally removing the layer via chemical or physical means. Coating removal processes such as these can be effective, but tend to be slow, equipment-intensive, or labor-intensive for removing durable coatings and are therefore expensive. A means to easily remove and/or spot-repair coatings such as these is needed in the art.
[0018] Another aspect of coating or surface treatment repair is addressing significant wear or damage that extends into the substrate material. In some applications, infrequent but severe damage events can occur that will breach protective coatings and penetrate deeply into the substrate. For instance, Gravett presents data from a field inspection campaign of foreign object damaged turbine engine compressor blades (“The Foreign Object Damage Project of the PRDA V HCF Materials and Life Methods Program”, 4th National Turbine Engine High Cycle Fatigue Conference, Monterey, Calif., USA, Feb. 9, 1999). Data presented shows that the depth of foreign object damage to compressor blades can range from 0.02 inches to 0.5 inches, with an average depth of 0.06 inches. This average damage depth is much greater than a typical protective coating or treated surface.
[0019] Surface damage to such depths is unacceptable for some applications, but is acceptable for others. In the case of cutting tools, significant erosion or wear of the tool will cause parts machined by the tool to be out of tolerance and therefore unacceptable. However, in the case of turbine engines, significant wear and erosion on in-service compressor blades is commonplace. Gupta presents data showing local compressor airfoil erosion can be on the order of 10 percent of the original airfoil chord (“Protective Coatings in the Gas Turbine Engine”, Surface and Coatings Technology, Vol. 68/69, 1994, pp. 1-9). Schwind presents similar, but more detailed information regarding blade erosion (“Blade Erosion Effects on Aircraft-Engine Compressor Performance”, Department of Energy Report DOE/CS/50095-T2, 1982) In fact, special procedures have been developed to classify and repair such damage to turbine engine blades. U.S. Pat. No. 5,625,958 (DeCoursey) teaches a method to determine the service life remaining in a blade after erosion has occurred. U.S. Pat. No. 5,197,191 (Dunkman) teaches a method and apparatus to repair gouged out and damaged leading and trailing edges of gas turbine engine blades by cutting away a curved section including the damaged area and forming a blend radius along the repaired edge. Clearly, it would be advantageous to coat or surface treat parts such as turbine engine airfoils to improve their erosion resistance and durability, yet retain the ability to repair the parts as is common in the art.
BRIEF SUMMARY OF THE INVENTION
[0020] The present invention discloses and teaches restoration of durable coatings or surface treatments on metal substrates and how to overcome deficiencies of the prior art.
[0021] Various embodiments of this invention disclose and teach the following methods of how to:
[0022] Restore damaged durable coatings or surface treatments on metal substrates.
[0023] Restore damaged CVD, PVD, plasma spray, and reactive coatings or surface treatments on metal substrates.
[0024] Restore damaged functionally gradient coatings or surface treatments on metal substrates.
[0025] Spot-repair damaged durable coatings or surface treatments on metal substrates.
[0026] Restore protective surfaces on the damaged areas of substrates without excessive buildup of repair material on undamaged areas.
[0027] Spot-repair durable coatings or surface treatments while allowing smoothing and blending of local part damage to acceptable conditions or dimensions prior to conducting the surface repair.
[0028] Spot-repair durable coatings or surface treatments to restore the protective surface over weld repair areas on metal substrates.
[0029] Reduce the difficulty of removing protective top-coats from metal substrates as part of surface repairs.
[0030] Reduce the difficulty of removing protective top-coats from metal substrates in conjunction with spot-repair of coatings or surface treatments that lie between the top-coats and the substrates.
[0031] Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of the preferred embodiment of the invention when taken in conjunction with the drawings and the appended claims.
[0032] All articles deriving from the methods disclosed in this invention are within the scope of this invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0033] [0033]FIG. 1 represents a portion of a functionally gradient surface with damaged and undamaged areas.
[0034] [0034]FIG. 2 represents a time vs. treatment depth curve for reactive metals processes.
[0035] [0035]FIG. 3A represents a portion of a functionally gradient surface with damaged and undamaged areas.
[0036] [0036]FIG. 3B represents the surface of FIG. 3A after repair of the present invention.
[0037] [0037]FIG. 4 represents a repair treatment curve of the present invention compared to a reactive metals process used to form the original surface.
[0038] [0038]FIG. 5 represents the present invention as applied to airfoil portions of gas turbine engine compressor blades and vanes.
[0039] [0039]FIG. 6 represents the present invention as applied to stem areas of gas turbine engine compressor variable vanes.
[0040] [0040]FIG. 7 represents the present invention as applied to dovetail areas of gas turbine engine compressor blades.
[0041] [0041]FIG. 8 represents the present invention as applied to airfoil portions of gas turbine engine turbine blades and vanes.
DETAILED DESCRIPTION OF THE INVENTION
[0042] Surface Repair Process
[0043] [0043]FIG. 1 represents a portion of a functionally gradient surface. Substrate atoms 1 comprise substrate 5 . Substrate atoms 1 may comprise a single metal or an alloy of several elements. Substrate atoms 1 and interstitial atoms 3 comprise gradient layer 7 and hard surface layer 9 . Interstitial atoms 3 may comprise a single element or multiple elements. Some interstitial atoms 3 in gradient layer 7 and surface layer 9 may be chemically combined with substrate atoms 1 to form compounds of the elements present. Surface layer 9 consists primarily of such compounds. Portions of gradient layer 7 and hard surface layer 9 are missing in damaged area 11 . Gradient layer 7 and hard surface layer 9 are intact in undamaged area 13 .
[0044] [0044]FIG. 2 represents a time vs. treatment depth curve 15 for a typical reactive metals process that could include but is not limited to boronizing, carburizing, nitridizing and carbonitridizing. In such processes, depth of treatment is dependant upon volume diffusion of interstitial atoms though the lattice of substrate atoms. Depth of treatment is proportional to the square root of time. Therefore, beginning treatment rate 17 is substantially higher than final treatment rate 19 . Diffusion of interstitial atoms slows as surface treatment depth increases, thereby decreasing treatment rate as time progresses.
[0045] Referring to FIGS. 1 and 2, the outcome of applying the process of FIG. 2 to the damaged surface of FIG. 1 is as follows: The missing surface layer and thinned gradient layer in damaged area 11 present less of a diffusion barrier to additional treatment. Damaged area 11 therefore initially experiences a much higher rate of interstitial atom diffusion than undamaged area 13 , e.g., initial treatment rate 17 . As the process continues treatment rate slows to final rate 19 , and surface treatment depth in the damaged area increases to nearly the same depth as in the original undamaged area—refer to FIG. 3. This results in repaired hard surface 21 and repaired gradient layer 23 . Note that damaged area 11 is not built-up to replenish the missing material, and that undamaged area 13 receives little additional treatment. The preferred reactive metals process for the present invention is enhanced plasma nitriding as taught in expired U.S. Pat. No. 4,460,415 (Korhonen). The use of this and other reactive metals processes to create such spot-repairs is not known in the prior art.
[0046] Repair Process Optimization
[0047] Minimal treatment of undamaged areas is extremely important from a surface repair standpoint. This means that damaged areas can effectively be “spot-repaired” without excessive build up in undamaged areas. This avoids problems associated with excessive surface treatment depth such as reduced fatigue strength. In fact, the repair treatment can be purposely made less efficient to ensure no additional treatment in undamaged areas. Refer to FIG. 4. Treatment curve 15 from FIG. 2 is shown along with repair curve 25 . Original treatment time 27 establishes original treatment depth 29 . Repair curve 25 is selected to produce a slightly decreased depth of treatment than original treatment curve 15 for an equivalent treatment time. For example, in plasma nitriding this can be accomplished using process changes that include, but are not limited to higher vacuum chamber pressures and lower treatment voltages. Repair treatment time 31 can be selected to be slightly longer than original treatment time 27 . This produces repair treatment depth 33 that is nearly the same as original treatment depth 29 . This repair optimization ensures that depth of treatment for damaged areas is nearly the same as the original treatment depth. However, no additional treatment of undamaged areas occurs since final repair treatment depth 33 is less than treatment depth 29 on the undamaged areas. Even if repair treatment time 27 were made significantly longer, the repair curve would not yield additional treatment in undamaged areas. The optimum repair process is defined as that which produces maximum treatment in damaged areas, minimum treatment in undamaged areas, all in minimum time.
EXAMPLE 1
[0048] Repair of Turbine Engine Blade Airfoils
[0049] One example application of the present invention is repair of durable surfaces for turbine engine airfoils. For instance, turbine engine compressor blades and vanes suffer from a multitude of degradation mechanisms including erosion, corrosion, impact damage, fretting wear and fretting fatigue. Erosion of airfoil portions of blades and vanes is common. Refer to FIG. 5. Untreated compressor airfoil 35 has damage 37 on the airfoil leading edge. Damage 37 could be due to erosion or foreign object damage (FOD). Standard industry practice for maintaining and repairing uncoated compressor blades involves smoothing and blending minor damage, then returning the blades to service. U.S. Pat. No. 5,197,191 (Dunkman) describes this process. The smoothing and blending produces results represented by smoothed area 39 on airfoil 35 .
[0050] This process is supplemented using the present invention as follows: A durable functionally gradient surface is applied to airfoil 35 prior to placing it in service. Processes including, but not limited to boronizing, carburizing, nitridizing and carbonitridizing could be used. The functionally gradient surface increases the service life of the blade, but it eventually receives damage and must be repaired. Damage 37 on the airfoil is smoothed and blended per industry standard practice as represented by smoothed area 39 , then airfoil 35 undergoes the repair process of the present invention to restore the functionally gradient surface only in the damaged and smoothed areas. As can readily be seen, the repair process of the present invention is compatible with and enhances established industry practices for airfoil repair and use.
EXAMPLE 2
[0051] Repair of Turbine Engine Variable Vane Stem Areas
[0052] The present invention can also be used to repair the stem areas of variable stator vanes in gas turbine engine compressors. Refer to FIG. 6. Variable stator vane 40 includes stem areas 41 and airfoil areas 42 . Also shown are bushing 43 and a portion of the engine casing 44 . Stem areas 41 act as rotating bearing surfaces for vane 40 during engine operation and therefore are subject to sliding wear. Stem areas 41 can be, and are preferably repaired simultaneously with airfoil areas 42 using the process described in Example 1. If airfoil areas 42 have experienced wear (erosion) and stem areas 41 have not, the present invention ensures repair of airfoil areas 42 whereas stem areas 41 receive little or no additional treatment.
EXAMPLE 3
[0053] Repair of Turbine Engine Blade Dovetail Areas
[0054] In Example 1, the focus was repair of the airfoil portion of a turbine engine blade. Dovetail areas of blades could also receive treatment as part of airfoil repair using the present invention. It is important to consider potential impacts of the present invention on repairing dovetail areas. This ensures the present invention does not conflict with existing operational or repair considerations.
[0055] Copper-nickel-indium and other soft anti-fretting and anti-wear coatings are commonly employed on compressor and turbine blade dovetails in the prior art. U.S. Pat. No. 5,368,444 (Anderson) describes the use of such coatings. Referring to FIG. 7, blade 45 has anti-fretting or anti-wear coating 47 applied to dovetail areas 49 . Coating 47 is often stripped and reapplied as part of blade repair, most often when excessive wear of coating 47 occurs. Dovetail areas 49 can be isolated from the repair process of the present invention by using masking and/or substrate holders that prevent reactive metals treatment of these areas. However, if coating 47 is excessively worn and must be stripped, the present invention is useful for expediting the stripping process.
[0056] The present invention is used to supplement repair of dovetail areas 49 as follows: Durable functionally graded surface 51 is applied to blade 45 , including dovetail areas 49 , prior to applying coating 47 . Coating 47 is then applied over functionally gradient surface 51 in the dovetail area, and the blade is placed into service. If coating 47 experiences excessive wear and must be stripped, functionally gradient surface 51 on the dovetail substrate makes these areas more resistant to erosion damage from the stripping process (e.g., grit blasting). Undesired minor dovetail area damage to surface 51 incurred while stripping coating 47 is then repaired using the present invention, preferably in conjunction with repair of airfoil portion 53 of the blade per Example 1. Coating 47 is then reapplied and blade 45 is returned to service.
EXAMPLE 4
[0057] Repair of Turbine Engine Blades with Thermal Barrier Coatings
[0058] Thermal barrier coatings are often used on turbine blades to protect the underlying metal substrate, and are also commonly stripped using processes including grit blasting as part of repair procedures. U.S. Pat. No. 4,576,874 (Spengler, et al) and U.S. Pat. No. 5,813,118 (Roedl, et al) describe thermal barrier coatings commonly employed. Referring to FIG. 8, thermal barrier coating 53 is applied to airfoil 55 of turbine blade 57 . A metallic bond coat 54 is often applied between thermal barrier coating 53 and airfoil 55 . Bond coat 54 is compositionally tailored to grow an adherent, predominately aluminum oxide scale to inhibit oxidation of the blade 57 and provide a satisfactory bonding surface for thermal barrier coating 53 . Dense overcoat 56 is also sometimes applied over thermal barrier coating 53 . Note that cooling holes 63 may be present in airfoil 55 . Coatings 53 and 56 are often stripped and reapplied as part arts of blade repair, most often upon excessive spalling of these coatings. Usual repair practice in the existing art is to strip coatings 53 and 56 using chemical and mechanical means while attempting to leave bond coat 54 intact. If bond coat 54 is damaged it too, must be stripped. U.S. Pat. No. 5,972,424 (Draghi, et al) discusses these repair procedures. Weld repairs of airfoil 55 can also be made as described in U.S. Pat. No. 5,686,001 (Wrabel, et al).
[0059] The present invention makes the stripping process more efficient, and is used to supplement repair of airfoil 55 as follows: Durable functionally graded surface 59 is applied to airfoil 55 , including fir tree portion 61 , prior to applying coatings 54 , 53 or 56 . Coatings 54 , 53 and if necessary 56 are then applied over functionally gradient surface 59 on airfoil 55 and the blade is placed into service. When coatings 53 and 56 experience excessive wear and must be stripped, functionally gradient surface 59 on the airfoil substrate makes these areas more resistant to erosion (e.g., grit blasting). Undesired minor damage to surface 59 incurred while stripping coatings 54 , 53 and 56 is then repaired using the present invention, preferably in conjunction with repair of fir tree portion 61 of the blade per Example 1. The present invention will also restore a functionally gradient surface over weld repair areas. The present invention does not clog cooling holes 63 as can occur with other coating processes. Coatings 54 , 53 and if necessary 56 are then reapplied and blade 57 is returned to service. Note that bond coat 54 and dense overcoat 56 may be omitted without departing from the present invention.
[0060] Alternatives
[0061] It should be understood that the present invention is not restricted to repairing surfaces originally produced using reactive metals coating processes. Functionally gradient surfaces produced using CVD, PVD, plasma spraying and other processes can also be repaired. The repair process of the present invention can also be used to repair such surfaces, providing the elements present and their concentrations by depth are similar to those expected for the repair process.
[0062] Conclusion
[0063] Therefore it may be seen that the present invention includes many advantages, most notably the ability to spot-repair durable functionally gradient surfaces.
[0064] While this invention has been described in specific detail with reference to the disclosed embodiments, it will be understood that many variations and modifications may be effected within the spirit and scope of the invention as described in the appended claims. | This invention pertains to the repair of parts comprising metals, and surfaces and coatings of these parts using reactive metals coating processes. Processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma spray, and reactive coating (boronizing, carburizing, nitridizing, carbonitridizing, etc.) are known for producing durable coatings or surfaces on metal parts, and the present invention provides a means to spot-repair these coatings or surfaces without excessive buildup of repair material on undamaged areas. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 10/933,843, filed Sep. 2, 2004, now U.S. Pat. No. 7,064,006, issued Jun. 20, 2006, which is a divisional of application Ser. No. 09/989,326, filed Nov. 20, 2001, now U.S. Pat. No. 6,911,723, issued Jun. 28, 2005, which is a continuation of application Ser. No. 09/247,009, filed Feb. 8, 1999, now U.S. Pat. No. 6,351,028, issued Feb. 26, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the packaging of integrated circuit devices by interposing a plurality of integrated circuit devices within a common package for increased semiconductor device density. More particularly, the present invention relates to multiple integrated circuit devices in a stacked configuration that uses a spacing element allowing increased semiconductor device density and allowing better thermal conductivity for dissipating heat for semiconductor memory devices, semiconductor processor type devices, or any desired type integrated circuit semiconductor device.
2. State of the Art
Integrated circuit semiconductor devices have been known since shortly after the development of the electronic transistor device. The goals in designing and manufacturing semiconductor devices have been to make the devices smaller, more complex, with higher densities, and to include additional features. One method that improves the features and the densities of the semiconductor devices is to shrink the line sizes used in the lithographic process step in fabricating semiconductor devices. For example, each one-half reduction in line width of the circuits of the semiconductor device corresponds to a four-fold increase in chip density for the same size device. Unfortunately, increasing density simply through improved lithographic techniques is limited because of physical limits and the cost factor of scaling down the dimensions of the semiconductor device. Accordingly, alternative solutions to increase semiconductor device density have been pursued. One such alternative has been the stacking of multiple semiconductor devices. However, conventional stacking of semiconductor devices can lead to excessive local heating of the stacked semiconductor devices as well as lead to restraints on how the heat may be removed from the stacked semiconductor devices.
One approach of semiconductor device (die) stacking uses a chip geometry known as cubic chip design and is illustrated in drawing FIG. 1 (Prior Art). The device 2 includes substrate 4 , upon which a plurality of semiconductor devices 6 is stacked. Each semiconductor device 6 is connected to another semiconductor device and to substrate 4 via bonding elements 8 , which are then encased in a suitable type of resin material 10 forming a package. The semiconductor devices 6 are designed such that an overhanging flange is provided by cutting the edges of a semiconductor device at approximately a 30- to 35-degree angle and inverting the device for the bonding connection. This allows the semiconductor devices 6 to stack one on top of another in a uniform and tight arrangement.
Unfortunately, the cubic design has several disadvantages that make it unsuitable for all types of semiconductor device packaging design. One disadvantage is that the cubic stacking of the semiconductor devices one on top of another causes stack stresses or bending, or both. Additionally, because of stack stressing or bending, there is a limit to the number of semiconductor devices that can be stacked one on top of another. Also, if the adhesive of the stack weakens and comes loose, the semiconductor device will shift, which can result in the breaking of the bonds between the various devices 6 and the substrate 4 . Furthermore, the stacking of the semiconductor devices generates thermal and mechanical problems where the semiconductor devices generate heat that cannot be easily dissipated when they are stacked one upon another.
Additional solutions have been developed in the prior art and are illustrated in U.S. Pat. Nos. 5,585,675 ('675 patent) and 5,434,745 ('745 patent). The '675 patent discloses a packaging assembly for a plurality of semiconductor devices that provides for stacking of the semiconductor devices. The packaging assembly uses angularly offset pad-to-pad via structures that are configured to allow three-dimensional stacking of the semiconductor devices. The electrical connection is provided to a via structure where multiple identical tubes are provided in which a semiconductor device is mounted and then one tube is mounted on top of another tube. The angularly offset via pads are provided through the stack tube structure for connection. One disadvantage with the angularly offset pad via structure is that the tubes must be precisely manufactured so that the vias are lined up properly. Further, the semiconductor devices must be set within strict tolerances for the tubes to stack one on top of another so the vias can be aligned properly as well.
The '745 patent discloses a stacked semiconductor device carrier assembly and a method for packaging interconnecting semiconductor devices. The carriers are constructed from a metal substrate onto which the semiconductor device attaches. Next, the semiconductor device is wired bonded to the conductor pattern on the substrate and each conductor is routed to the edge of the substrate where it is connected to a half circle of a metallized through-hole. Again, the '745 patent discloses a tube-like design with half circle vias for allowing interconnection to the stack of multiple semiconductor devices.
One disadvantage with the stack type semiconductor device carrier of the '745 patent is that the tubes are connected one with another. Any potential rework operation involving the wire connections is very difficult in that the tube assemblies must be disassembled for such a rework operation.
Accordingly, a multiple stacked arrangement of semiconductor devices and associated methods of stacking that reduce stack stresses or bending of the semiconductor devices, that allow easier reworking of the wiring interconnecting bond pads of the semiconductor devices, that protect the bond pads of each semiconductor device from the other devices, and that effectively remove heat from the semiconductor devices are needed.
BRIEF SUMMARY OF THE INVENTION
The present invention is directed to the packaging of integrated circuit devices by interposing a plurality of integrated circuit devices within a common package for increased semiconductor device density. The present invention relates to multiple integrated circuit devices in a stacked configuration that uses a spacing element for allowing increased device density and the removal of thermal energy from semiconductor devices and the methods for the stacking thereof.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a prior art cubic semiconductor device package;
FIG. 2 is a cross-sectional diagram of an embodiment of the T-interposer devices of the present invention used for the stacking of multiple semiconductor devices according to the present invention;
FIG. 3 is a perspective view of an embodiment of a single T-interposer of the present invention;
FIG. 4 is a cross-sectional view of multiple semiconductor devices mounted to an embodiment of a T-interposer according to the present invention;
FIG. 5 is a cross-sectional diagram of another embodiment of T-interposers having differing dimensions of the present invention;
FIG. 6 is a perspective view of an embodiment of an inverted T-interposer of the present invention;
FIG. 7 is a cross-sectional view of a multiple semiconductor device (die) package that has a sealant about the interconnections;
FIG. 8 is a cross-sectional view of another embodiment of the T-interposer of the present invention in a stacked configuration;
FIG. 9 is a cross-sectional view of another embodiment of the T-interposer of the present invention in a stacked configuration; and
FIG. 10 is a block diagram of an electronic system incorporating the semiconductor device of FIG. 2 and the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Illustrated in a cross-sectional diagram in drawing FIG. 2 is a multi-stacked semiconductor device structure utilizing a T-interposer device having a T-shape in cross-section of the present invention. Multiple stack unit 20 comprises a substrate 22 ; a first semiconductor device 24 disposed on substrate 22 , a first T-interposer 26 disposed on the first semiconductor device 24 , and multiple semiconductor devices 24 disposed on multiple T-interposers 26 . Each semiconductor device 24 includes a plurality of bond pads 28 thereon. Each T-interposer 26 includes a substantially vertical stem 27 having substantially vertical edges and T-bar cross portions or members 29 having substantially horizontal edges or surfaces with respect to the vertical edges of the stem 27 , the upper surface 29 ′ of the T-bar members 29 extending across the stem 27 to form a substantially horizontal surface with respect to the vertical upon which to mount one or more semiconductor devices 24 . The flange (horizontal) edges or surfaces of each T-interposer 26 are offset so that a portion of the active surface 25 of each semiconductor device 24 attaches to the base of the stem 27 of an adjacent T-interposer 26 while bond pads 28 of each semiconductor device 24 are exposed for wire bonding to substrate 22 or another semiconductor device 24 or the circuit of another T-interposer 26 . Each semiconductor device 24 is subsequently stacked one on top of another in a horizontal plane with a T-interposer 26 disposed between each semiconductor device 24 . Each semiconductor device 24 may be bonded either to the T-interposer 26 , another semiconductor device 24 , or to substrate 22 or both. In this structure, the T-interposer 26 is placed on an individual semiconductor device 24 as other semiconductor devices 24 are stacked one on top of another, each stacked semiconductor device 24 being located in a separate substantially horizontal plane. This provides for access and protection to bond pads 28 of the semiconductor devices 24 . The T-interposer 26 can be made of a variety of materials, including those materials having a coefficient of thermal expansion (CTE) matching or similar to the semiconductor device(s) 24 , such as silicon, ceramic, alloy 42 , etc., and having the desired thermal energy (heat transfer or conductivity) characteristics for the transfer of thermal energy or beat from semiconductor devices in contact with or around T-interposer 26 . Alternately, the material for the T-interposer 26 may be selected for thermal energy insulation effects to prevent thermal energy from being transferred from one semiconductor device 24 connected to the T-interposer to another semiconductor device 24 connected to the T-interposer.
This protects the semiconductor devices 24 during the stacking and enables a variety of interconnections to be used between semiconductor devices 24 , T-interposers 26 , and/or substrates 22 . The interconnection between semiconductor devices 24 or T-interposers 26 or substrates 22 , or both, uses conductor traces, tape, wire bonding, conductive paste, or conductive adhesives, or any other type of suitable semiconductor interconnection technique known to one skilled in the art. The T-interposer 26 allows bond pads 28 of the semiconductor device 24 to be exposed, so no additional rerouting steps are required to reroute a bond pad 28 to the edges. This is advantageous over the prior art structures, such as the cubic design shown in drawing FIG. 1 , in that the shell case or the interconnection requires additional processing in those materials and additional time. Further, the flanged edges forming the stem 27 of T-interposer 26 allow direct connection to the bond pads 28 and contact to all four sides of semiconductor devices 24 . This allows increased interconnect density between a substrate and a plurality of semiconductor devices.
In multiple stack unit 20 , if desired, the first semiconductor device 24 , which is mounted to substrate 22 , can be a microprocessor while the second semiconductor device 24 , located above T-interposer 26 mounted to the first semiconductor device 24 located on the substrate 22 , can be a semiconductor memory device, which allows for mixing and matching of the semiconductor devices such as memory devices and processing devices and control logic devices for a complete, integrated semiconductor device package.
Referring to drawing FIG. 3 , further illustrated is an inverted T-interposer 26 as shown in drawing FIG. 2 . Again, T-interposer 26 can be manufactured to match the same CTE of the semiconductor device 24 or the semiconductor device substrate 22 used for each of semiconductor devices 24 , or both. This allows T-interposer 26 to serve as a thermal or heat dissipation device between each semiconductor device 24 while allowing for greater heat dissipation than would otherwise be possible were the semiconductor devices 24 stacked directly upon each other. Further, T-interposer 26 provides electrical insulation between each semiconductor device 24 that would not be otherwise possible were the semiconductor devices to be stacked one upon another such as in the prior art described in drawing FIG. 1 . Additionally, the T-interposer 26 may be comprised of two different materials to provide both thermal conductivity from one semiconductor device and thermal insulation with respect to a second semiconductor device. For instance, the stem 27 may be of a thermally conductive material while the T-bar members 29 are formed of a thermally insulative material; the stem 27 may be joined to the T-bar member(s) 29 by any suitable means, such as adhesive bonding, etc. The T-interposer 26 of the present invention provides for much greater bonding edge relief for different types of connection devices with respect to the bond pad 28 location on the active surface 25 of the semiconductor device 24 than that shown in the prior art device illustrated in drawing FIG. 1 and greater insulation capacity for the bond pads 28 of the semiconductor devices 24 with the T-interposer 26 in place. Finally, a top T-interposer 26 is further provided for capping the device to protect and promote heat transfer from the last semiconductor device 24 forming the multiple stacked unit 20 .
Still referring to the T-interposer 26 illustrated in drawing FIG. 3 , an electrical bonding interconnect element 30 is manufactured into T-interposer 26 to provide subsequent connection should the bond pads 28 on active surface 25 of the semiconductor device 24 be mounted or connected to the T-shaped interposer 26 for electrical interconnection.
Referring to drawing FIG. 4 , illustrated is a cross-section diagram of multiple semiconductor devices 38 and 40 being mounted to a single T-interposer 26 . T-interposer 26 is mounted to a substrate 36 . Substrate 36 includes bond pads/circuits 28 thereon. Semiconductor device 38 can be a processor type semiconductor device while semiconductor device 40 can be a memory type semiconductor device. Semiconductor device 38 and semiconductor device 40 are interconnected via bond pads 28 and further connected to bond pads or circuits 28 on substrate 36 . Additionally, the bonding wire from one bond pad or circuit 28 , such as on device 40 , can connect directly to the device structure to which the substrate 36 is to be permanently mounted. This can be the actual circuit board, such as a mother board used in a computer system. Of course, other direct connection options will be readily apparent to one skilled in the art.
Referring to drawing FIG. 5 , illustrated is a cross-sectional diagram of an arrangement of multiple semiconductor devices 24 similar to that illustrated in drawing FIG. 4 . The present invention illustrated in drawing FIG. 5 further adds multiple stacking upon a particular semiconductor device 24 . Multiple T-interposers 26 are provided and are of similar sizes. Additionally, semiconductor device 24 can be directly connected to T-interposer 26 below bond pad 28 thereon. In this manner, substrate 36 mounts directly to mother board substrate 22 where additional bonding pads 28 are provided in substrates 22 and 36 .
Referring to drawing FIG. 6 , depicted is an alternative embodiment T-interposer 126 of the present invention, which is similar to the embodiment of the T-interposer 26 illustrated in drawing FIG. 3 . As illustrated in drawing FIG. 6 , the T-interposer 126 includes additional recessed sections all around. The entire recessed periphery allows semiconductor devices that have connection pads around the entire perimeter of the device to be exposed for connection. In this manner, greater inter-connectivity is achieved with the ability to connect very dense interconnected circuit devices to other semiconductor devices. Additionally, ball weld spots 128 are provided as well and allow direct electrical and mechanical connection of any subsequent semiconductor devices. The stem 127 of the T-interposer 126 includes T-members 129 therearound and substantially horizontal surface 129 ′ located thereabove as described hereinbefore with respect to T-interposer 26 .
Referring to drawing FIG. 7 , illustrated is a cross-sectional view of a multiple stack unit 20 that is completely sealed or packaged. Again, a substrate 22 is provided upon which a first semiconductor device 24 is mounted with a T-interposer 26 mounted to the first semiconductor device 24 . A final cap or top T-interposer 26 is further provided on top of the entire stack unit 20 . Lastly, an epoxy interconnect 50 is provided for sealing and/or packaging and electrically isolating the bonding performed between the multiple semiconductor devices 24 . If desired, the top of the unit 20 may include a heat sink 52 of suitable type material which may include one or more fins 54 (shown in dashed lines) for additional thermal control of the heat from the unit 20 .
Referring to drawing FIG. 8 , illustrated is another embodiment of the T-interposer 26 of the present invention in a stacked arrangement between semiconductor devices 40 , which are electrically connected by wires 56 to circuits 58 of the substrate 36 . In this embodiment of the T-interposer 26 of the present invention, one T-bar member 29 has a greater length or extends farther than the opposing T-bar member 29 of the T-interposer 26 to provide greater bonding edge relief for different types of connection devices with respect to the bond pad location on the active surface of the semiconductor device 24 than the bonding edge relief provided by the T-bar member 29 on the other side of the T-interposer 26 . In this manner, the T-interposer 26 is not centrally located on a portion of the active surface of the semiconductor device 40 but, rather, is located off-center on a portion of the active surface of the semiconductor device 40 . Such a T-interposer 26 allows for the accommodation of differing sizes and shapes of semiconductor devices 40 and bond pad arrangements thereon for interconnection to the circuits 58 of substrate 36 .
Referring to drawing FIG. 9 , illustrated is another embodiment of the T-interposer 26 of the present invention where the T-interposer 26 includes a plurality of stems 27 and T-bar members 29 to form the same, each stem 27 located on a portion of the active surface of a semiconductor device 40 , which is, in turn, located on a substrate 36 having circuits 58 located thereon connected by wires 56 while wires 62 electrically connect the semiconductor devices 40 located on surface 29 ′ of the T-interposer 26 to the circuits 60 located thereon. In this manner, the T-interposer 26 helps to increase the density of the semiconductor devices 40 located on the substrate 36 while providing thermal control of the heat generated from the semiconductor devices 40 located on the substrate 36 and on the surface 29 ′ of the T-interposer 26 .
Each T-interposer 26 can be manufactured in various manners; ideally, the T-interposer 26 consists of a unitary element that is milled or machined from a single piece. The side edges for producing the “T” effect are milled away to preserve the integral strength of the unitary piece. This design prevents fractures occurring in seams of the T-interposer where the top “T” portion is epoxied to the bottom as a separate element. If desired, T-interposer 26 can be made from separate pieces, one having a smaller width than the other, if the epoxy or adhesive used to connect the two elements is of sufficient strength to prevent fracturing or separation, or the strain and load placed on the seams were greatly reduced so as to minimize the possibility of fracturing.
The use of the T-interposer 26 for stacking bare dies has several advantages over prior art solutions. One advantage is that it reduces stack stresses or bending. Further, the T-interposer allows easier reworking of any bond interconnect when necessary. Additionally, as there are no stress problems inherent in stacking semiconductor devices upon other devices, as any number of devices can be stacked with T-interposer 26 used in separating device from device, thus allowing for greater device densities for memory devices and other type semiconductor devices. Also, several types of interconnect methods are possible with the T-interposer, such as wire bonding, ball bonding, flip-chip bonding, etc. Additional advantages include the bond pads of each semiconductor device being protected from one another in the device stack. Thermal and mechanical properties are improved because of the use of the T-interposer. The improved thermal and mechanical properties also allow for increased semiconductor device density for memory chips and SIMM type devices.
Those skilled in the art will appreciate that semiconductor devices according to the present invention may comprise an integrated circuit die employed for storing or processing digital information, including, for example, a Dynamic Random Access Memory (DRAM) integrated circuit die, a Static Random Access Memory (SRAM) integrated circuit die, a Synchronous Graphics Random Access Memory (SGRAM) integrated circuit die, a Programmable Read-Only Memory (PROM) integrated circuit die, an Electrically Erasable PROM (EEPROM) integrated circuit die, a flash memory die and a microprocessor die, and that the present invention includes such devices within its scope. In addition, it will be understood that the shape, size, and configuration of bond pads, jumper pads, dice, and lead frames may be varied without departing from the scope of the invention and appended claims. For example, the jumper pads may be round, oblong, hemispherical or variously shaped and sized so long as the jumper pads provide enough surface area to accept attachment of one or more wire bonds thereto. In addition, the bond pads may be positioned at any location on the active surface of the die.
As shown in drawing FIG. 10 , an electronic system 130 includes an input device 132 and an output device 134 coupled to a processor device 136 , which in turn, is coupled to a memory device 138 incorporating the exemplary semiconductor device 24 and T-interposer 26 of drawing FIG. 2 .
Accordingly, the claims appended hereto are written to encompass all semiconductor devices including those mentioned. Those skilled in the art will also appreciate that various combinations and obvious modifications of the preferred embodiments may be made without departing from the spirit of this invention and the scope of the accompanying claims. | Multiple integrated circuit devices in a stacked configuration that use a spacing element for allowing increased device density and increased thermal conduction or heat removal for semiconductor devices and the methods for the stacking thereof are disclosed. | 7 |
CLAIM OF PRIORITY
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/711,973, entitled “SYSTEM AND METHOD FOR MANAGING GARBAGE COLLECTION IN AN ON-DEMAND SYSTEM,” by Hunt et al., filed Oct. 10, 2012, the entire contents of which are incorporated herein by reference.
COPYRIGHT NOTICE
[0002] 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
[0003] One or more implementations relate generally to memory management, and more particularly to performing garbage collection on memory.
BACKGROUND
[0004] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions.
[0005] Many current systems utilize one or more automatic memory management mechanisms to address memory usage by one or more applications within the system. Unfortunately, techniques for performing such memory management have been associated with various limitations. Just by way of example, many memory management mechanisms may create a delay in application execution. Accordingly, it is desirable to provide techniques for conditionally performing garbage collection.
BRIEF SUMMARY
[0006] In accordance with embodiments, there are provided mechanisms and methods for conditionally performing garbage collection. These mechanisms and methods for conditionally performing garbage collection can enable reduced application delay, improved data management efficiency, enhanced customer response, etc.
[0007] In an embodiment and by way of example, a method for conditionally performing garbage collection is provided. In one embodiment, a predetermined portion of memory is identified within a system. Additionally, one or more aspects of the predetermined portion of memory are compared to a threshold. Further, garbage collection is conditionally performed on the predetermined portion of memory, based on the comparison.
[0008] While one or more implementations and techniques are described with reference to an embodiment in which conditionally performing garbage collection is implemented in a system having an application server providing a front end for an on-demand database system capable of supporting multiple tenants, the one or more implementations and techniques are not limited to multi-tenant databases nor deployment on application servers. Embodiments may be practiced using other database architectures, i.e., ORACLE®, DB2® by IBM and the like without departing from the scope of the embodiments claimed.
[0009] Any of the above embodiments may be used alone or together with one another in any combination. The one or more implementations encompassed within this specification may also include embodiments that are only partially mentioned or alluded to or are not mentioned or alluded to at all in this brief summary or in the abstract. Although various embodiments may have been motivated by various deficiencies with the prior art, which may be discussed or alluded to in one or more places in the specification, the embodiments do not necessarily address any of these deficiencies. In other words, different embodiments may address different deficiencies that may be discussed in the specification. Some embodiments may only partially address some deficiencies or just one deficiency that may be discussed in the specification, and some embodiments may not address any of these deficiencies.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] In the following drawings like reference numbers are used to refer to like elements. Although the following figures depict various examples, the one or more implementations are not limited to the examples depicted in the figures.
[0011] FIG. 1 illustrates a method for conditionally performing garbage collection, in accordance with one embodiment;
[0012] FIG. 2 illustrates a method for conditionally implementing a garbage collection event, in accordance with another embodiment:
[0013] FIG. 3 illustrates a block diagram of an example of an environment wherein an on-demand database system might be used; and
[0014] FIG. 4 illustrates a block diagram of an embodiment of elements of FIG. 5 and various possible interconnections between these elements.
DETAILED DESCRIPTION
General Overview
[0015] Systems and methods are provided for conditionally performing garbage collection.
[0016] As used herein, the term multi-tenant database system refers to those systems in which various elements of hardware and software of the database system may be shared by one or more customers. For example, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows for a potentially much greater number of customers.
[0017] Next, mechanisms and methods for conditionally performing garbage collection will be described with reference to example embodiments.
[0018] FIG. 1 illustrates a method 100 for conditionally performing garbage collection, in accordance with one embodiment. As shown in operation 102 , a predetermined portion of memory is identified within a system. In one embodiment, the predetermined portion of memory may include a portion of memory that may be available to/usable by/assigned to one or more applications within the system. For example, the predetermined portion of memory may include a portion of memory that may be occupied by one or more objects used by one or more applications within the system.
[0019] Additionally, in one embodiment, the predetermined portion of memory may include hardware memory. For example, the predetermined portion of memory may include volatile memory such as random access memory (RAM), static random access memory (SRAM), etc. In another example, the predetermined portion of memory may include non-volatile memory such as read-only memory (ROM), flash memory, mechanical memory (e.g. hard drive memory, etc.), etc. In another embodiment, the system may include a multi-tenant on-demand database system.
[0020] Further, in one embodiment, current application data may be stored in one or more locations of the predetermined portion of memory (e.g., such that those locations are allocated within the portion of memory, etc.). For example, data currently being used by one or more applications running within the system (e.g., live application data, etc.) may be stored in one or more available locations within the predetermined portion of the memory. In another embodiment, old application data may be stored in one or more locations of the predetermined portion of memory. For example, data that was previously used (and is not currently being used) by one or more applications (e.g., object data that is no longer being used by the one or more applications) within the system may be stored in one or more available locations within the predetermined portion of the memory.
[0021] Further still, in one embodiment, one or more locations of the predetermined portion of memory may be unused (e.g., deallocated, etc.). For example, one or more available locations within the predetermined portion of the memory may not be currently storing data used by one or more applications of the system. In another embodiment, the data used by one or more applications may include any type of data (e.g., metadata, etc.).
[0022] Also, it should be noted that, as described above, such multi-tenant on-demand database system may include any service that relies on a database system that is accessible over a network, in which various elements of hardware and software of the database system may be shared by one or more customers (e.g. tenants). For instance, a given application server may simultaneously process requests for a great number of customers, and a given database table may store rows for a potentially much greater number of customers. Various examples of such a multi-tenant on-demand database system will be set forth in the context of different embodiments that will be described during reference to subsequent figures.
[0023] In addition, as shown in operation 104 , one or more aspects of the predetermined portion of memory are compared to a threshold. In one embodiment, the one or more aspects that are compared to the threshold may include an occupancy level of the predetermined portion of memory. For example, the one or more aspects that are compared to the threshold may include an amount of free space within the predetermined portion of memory (e.g., the amount of memory within the predetermined portion of memory that is not currently assigned to an application within the system, etc.). In another example, the one or more aspects that are compared to the threshold may include an amount of used space within the predetermined portion of memory (e.g., the amount of memory within the predetermined portion of memory that is currently assigned to a running or non-running application within the system, etc.).
[0024] Furthermore, in one embodiment, the threshold may include a predetermined occupancy level for the predetermined portion of memory. For example, the threshold may include a predetermined amount of free space within the predetermined portion of memory, a predetermined amount of used space within the predetermined portion of memory, etc. In another embodiment, the threshold may be determined by a user. In yet another embodiment, the threshold may be determined dynamically based on one or more system characteristics (e.g., a size of the predetermined portion of memory, etc.). In still another embodiment, the threshold may include a percentage value, a numeric value, etc.
[0025] Further still, as shown in operation 106 , garbage collection is conditionally performed on the predetermined portion of memory, based on the comparison. In one embodiment, performing garbage collection on the predetermined portion of memory may include retrieving the predetermined portion of memory. For example, all data stored in the predetermined portion of memory may be retrieved.
[0026] Also, in one embodiment, performing garbage collection on the predetermined portion of memory may include determining, for each location of the predetermined portion of memory, whether such location is currently allocated. If it is determined that a location of memory is deallocated, then no action may be performed in association with that location. If it determined that a location of memory is allocated, then one or more additional actions may be performed in association with that location.
[0027] For example, for each location of the predetermined portion of memory, it may be determined whether data currently being used by one or more applications running within the system (e.g., live application data, etc.) is stored in that particular location within the predetermined portion of the memory. In another embodiment, if it is determined for a particular location that the data stored in that location is currently being used by one or more applications running within the system, no action may be taken (e.g., such location may not be reclaimed, etc.).
[0028] Further, in one embodiment, if it is determined for a particular location that the data stored in that location is not currently being used by one or more applications running within the system, one or more actions may be performed. For example, such location and/or data may be labeled as garbage. In another example, such location may be deallocated and returned to the available memory within the system.
[0029] Further still, in one embodiment, garbage collection may be performed on the predetermined portion of memory only if the threshold is met. For example, garbage collection may be performed on the predetermined portion of memory only if an occupancy level of the predetermined portion of memory exceeds a threshold occupancy level. In this way, garbage collection may only be performed when necessary on the predetermined portion of memory, which may avoid unnecessary retrieval of the predetermined portion of memory during the performance of garbage collection.
[0030] FIG. 2 illustrates a method 200 for conditionally implementing a garbage collection event, in accordance with another embodiment. As an option, the present method 200 may be carried out in the context of the functionality of FIG. 1 . Of course, however, the method 200 may be carried out in any desired environment. The aforementioned definitions may apply during the present description.
[0031] As shown in operation 202 , a garbage collection event is triggered within a system according to a schedule. In one embodiment, the schedule may include a garbage collection schedule that triggers the garbage collection event with a predetermined frequency. For example, the schedule may trigger garbage collection once every minute, once every five minutes, once every ten minutes, etc.
[0032] Additionally, as shown in operation 204 , a portion of memory associated with the garbage collection event is identified. In one embodiment, the portion of memory may include a plurality of locations within a predetermined portion of memory. For example, the portion of memory may include all locations within a portion of memory used for allocation by one or more applications within the system. In another embodiment, the portion of memory may be associated with a virtual machine (e.g., a Java® virtual machine, etc.). In yet another embodiment, the portion of memory may include metadata associated with one or more applications (e.g., an application metadata space, etc.).
[0033] Further, as shown in operation 206 , a current occupancy level of the associated memory is compared against an occupancy threshold. In one embodiment, the current occupancy level of the associated memory may include a comparison between an amount of locations within the predetermined portion of memory that have been allocated to one or more applications within the system (e.g., allocated locations, etc.) and an amount of locations within the predetermined portion of memory that have not been allocated to an application (e.g., free locations, etc.).
[0034] Further still, in one embodiment, the current occupancy level may be expressed as a percentage (e.g., a percent of the total associated memory that is not allocated, etc.). In yet another embodiment, the current occupancy level may be determined for a predetermined time (e.g., the time in which the garbage collection event was triggered within the system, etc.).
[0035] Also, as shown in operation 208 , the garbage collection event is conditionally implemented on the associated memory, based on the comparison. In one embodiment, the garbage collection event may be implemented on the associated memory if the current occupancy level of the associated memory is equal to or greater than the occupancy threshold. In another embodiment, the garbage collection event may not be implemented on the associated memory if the current occupancy level of the associated memory is less than the occupancy threshold.
[0036] In addition, in one embodiment, implementing the garbage collection event may conditionally reallocating one or more portions of the associated memory based on a determination as to whether the portion of memory is occupied by one or more objects no longer in use by one or more applications of the system. For example, a portion of the associated memory may be reallocated if it is determined that the portion of memory is occupied by one or more objects no longer in use by one or more applications of the system. In another example, a portion of the associated memory may not be reallocated if it is determined that the portion of memory is occupied by one or more objects that are still in use by one or more applications of the system.
[0037] Furthermore, in one embodiment, implementing the garbage collection may include retrieving the associated memory to reclaim available space. For example, the associated memory may be collected for analysis. In another embodiment, the execution of one or more applications may be suspended when garbage collections is being performed. For example, one or more applications that have allocated one or more objects to the associated memory may be temporarily suspended while garbage collection is being performed on the associated memory.
[0038] In this way, unnecessary garbage collections events may be avoided, which may prevent the unnecessary interruption of application execution within the system. Further, garbage collection pause times may be reduced, which may reduce average customer response times.
System Overview
[0039] FIG. 3 illustrates a block diagram of an environment 310 wherein an on-demand database system might be used. Environment 310 may include user systems 312 , network 314 , system 316 , processor system 317 , application platform 318 , network interface 320 , tenant data storage 322 , system data storage 324 , program code 326 , and process space 328 . In other embodiments, environment 310 may not have all of the components listed and/or may have other elements instead of, or in addition to, those listed above.
[0040] Environment 310 is an environment in which an on-demand database system exists. User system 312 may be any machine or system that is used by a user to access a database user system. For example, any of user systems 312 can be a handheld computing device, a mobile phone, a laptop computer, a work station, and/or a network of computing devices. As illustrated in FIG. 3 (and in more detail in FIG. 4 ) user systems 312 might interact via a network 314 with an on-demand database system, which is system 316 .
[0041] An on-demand database system, such as system 316 , is a database system that is made available to outside users that do not need to necessarily be concerned with building and/or maintaining the database system, but instead may be available for their use when the users need the database system (e.g., on the demand of the users). Some on-demand database systems may store information from one or more tenants stored into tables of a common database image to form a multi-tenant database system (MTS). Accordingly, “on-demand database system 316 ” and “system 316 ” will be used interchangeably herein. A database image may include one or more database objects. A relational database management system (RDMS) or the equivalent may execute storage and retrieval of information against the database object(s). Application platform 318 may be a framework that allows the applications of system 316 to run, such as the hardware and/or software, e.g., the operating system. In an embodiment, on-demand database system 316 may include an application platform 318 that enables creation, managing and executing one or more applications developed by the provider of the on-demand database system, users accessing the on-demand database system via user systems 312 , or third party application developers accessing the on-demand database system via user systems 312 .
[0042] The users of user systems 312 may differ in their respective capacities, and the capacity of a particular user system 312 might be entirely determined by permissions (permission levels) for the current user. For example, where a salesperson is using a particular user system 312 to interact with system 316 , that user system has the capacities allotted to that salesperson. However, while an administrator is using that user system to interact with system 316 , that user system has the capacities allotted to that administrator. In systems with a hierarchical role model, users at one permission level may have access to applications, data, and database information accessible by a lower permission level user, but may not have access to certain applications, database information, and data accessible by a user at a higher permission level. Thus, different users will have different capabilities with regard to accessing and modifying application and database information, depending on a user's security or permission level.
[0043] Network 314 is any network or combination of networks of devices that communicate with one another. For example, network 314 can be any one or any combination of a LAN (local area network), WAN (wide area network), telephone network, wireless network, point-to-point network, star network, token ring network, hub network, or other appropriate configuration. As the most common type of computer network in current use is a TCP/IP (Transfer Control Protocol and Internet Protocol) network, such as the global internetwork of networks often referred to as the “Internet” with a capital “I,” that network will be used in many of the examples herein. However, it should be understood that the networks that the one or more implementations might use are not so limited, although TCP/IP is a frequently implemented protocol.
[0044] User systems 312 might communicate with system 316 using TCP/IP and, at a higher network level, use other common Internet protocols to communicate, such as HTTP, FTP, AFS, WAP, etc. In an example where HTTP is used, user system 312 might include an HTTP client commonly referred to as a “browser” for sending and receiving HTTP messages to and from an HTTP server at system 316 . Such an HTTP server might be implemented as the sole network interface between system 316 and network 314 , but other techniques might be used as well or instead. In some implementations, the interface between system 316 and network 314 includes load sharing functionality, such as round-robin HTTP request distributors to balance loads and distribute incoming HTTP requests evenly over a plurality of servers. At least as for the users that are accessing that server, each of the plurality of servers has access to the MTS' data; however, other alternative configurations may be used instead.
[0045] In one embodiment, system 316 , shown in FIG. 3 , implements a web-based customer relationship management (CRM) system. For example, in one embodiment, system 316 includes application servers configured to implement and execute CRM software applications as well as provide related data, code, forms, webpages and other information to and from user systems 312 and to store to, and retrieve from, a database system related data, objects, and Webpage content. With a multi-tenant system, data for multiple tenants may be stored in the same physical database object, however, tenant data typically is arranged so that data of one tenant is kept logically separate from that of other tenants so that one tenant does not have access to another tenant's data, unless such data is expressly shared. In certain embodiments, system 316 implements applications other than, or in addition to, a CRM application. For example, system 316 may provide tenant access to multiple hosted (standard and custom) applications, including a CRM application. User (or third party developer) applications, which may or may not include CRM, may be supported by the application platform 318 , which manages creation, storage of the applications into one or more database objects and executing of the applications in a virtual machine in the process space of the system 316 .
[0046] One arrangement for elements of system 316 is shown in FIG. 3 , including a network interface 320 , application platform 318 , tenant data storage 322 for tenant data 323 , system data storage 324 for system data 325 accessible to system 316 and possibly multiple tenants, program code 326 for implementing various functions of system 316 , and a process space 328 for executing MTS system processes and tenant-specific processes, such as running applications as part of an application hosting service. Additional processes that may execute on system 316 include database indexing processes.
[0047] Several elements in the system shown in FIG. 3 include conventional, well-known elements that are explained only briefly here. For example, each user system 312 could include a desktop personal computer, workstation, laptop, PDA, cell phone, or any wireless access protocol (WAP) enabled device or any other computing device capable of interfacing directly or indirectly to the Internet or other network connection. User system 312 typically runs an HTTP client, e.g., a browsing program, such as Microsoft's Internet Explorer browser, Netscape's Navigator browser, Opera's browser, or a WAP-enabled browser in the case of a cell phone, PDA or other wireless device, or the like, allowing a user (e.g., subscriber of the multi-tenant database system) of user system 312 to access, process and view information, pages and applications available to it from system 316 over network 314 . Each user system 312 also typically includes one or more user interface devices, such as a keyboard, a mouse, trackball, touch pad, touch screen, pen or the like, for interacting with a graphical user interface (GUI) provided by the browser on a display (e.g. a monitor screen, LCD display, etc.) in conjunction with pages, forms, applications and other information provided by system 316 or other systems or servers. For example, the user interface device can be used to access data and applications hosted by system 316 , and to perform searches on stored data, and otherwise allow a user to interact with various GUI pages that may be presented to a user. As discussed above, embodiments are suitable for use with the Internet, which refers to a specific global internetwork of networks. However, it should be understood that other networks can be used instead of the Internet, such as an intranet, an extranet, a virtual private network (VPN), a non-TCP/IP based network, any LAN or WAN or the like.
[0048] According to one embodiment, each user system 312 and all of its components are operator configurable using applications, such as a browser, including computer code run using a central processing unit such as an Intel Pentium® processor or the like. Similarly, system 316 (and additional instances of an MTS, where more than one is present) and all of their components might be operator configurable using application(s) including computer code to run using a central processing unit such as processor system 317 , which may include an Intel Pentium® processor or the like, and/or multiple processor units. A computer program product embodiment includes a machine-readable storage medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the embodiments described herein. Computer code for operating and configuring system 316 to intercommunicate and to process webpages, applications and other data and media content as described herein are preferably downloaded and stored on a hard disk, but the entire program code, or portions thereof, may also be stored in any other volatile or non-volatile memory medium or device as is well known, such as a ROM or RAM, or provided on any media capable of storing program code, such as any type of rotating media including floppy disks, optical discs, digital versatile disk (DVD), compact disk (CD), microdrive, and magneto-optical disks, and magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data. Additionally, the entire program code, or portions thereof, may be transmitted and downloaded from a software source over a transmission medium, e.g., over the Internet, or from another server, as is well known, or transmitted over any other conventional network connection as is well known (e.g., extranet, VPN, LAN, etc.) using any communication medium and protocols (e.g., TCP/IP, HTTP, HTTPS, Ethernet, etc.) as are well known. It will also be appreciated that computer code for implementing embodiments can be implemented in any programming language that can be executed on a client system and/or server or server system such as, for example, C, C++, HTML, any other markup language, Java™, JavaScript, ActiveX, any other scripting language, such as VBScript, and many other programming languages as are well known may be used. (Java™ is a trademark of Sun Microsystems, Inc.).
[0049] According to one embodiment, each system 316 is configured to provide webpages, forms, applications, data and media content to user (client) systems 312 to support the access by user systems 312 as tenants of system 316 . As such, system 316 provides security mechanisms to keep each tenant's data separate unless the data is shared. If more than one MTS is used, they may be located in close proximity to one another (e.g., in a server farm located in a single building or campus), or they may be distributed at locations remote from one another (e.g., one or more servers located in city A and one or more servers located in city B). As used herein, each MTS could include one or more logically and/or physically connected servers distributed locally or across one or more geographic locations. Additionally, the term “server” is meant to include a computer system, including processing hardware and process space(s), and an associated storage system and database application (e.g., OODBMS or RDBMS) as is well known in the art. It should also be understood that “server system” and “server” are often used interchangeably herein. Similarly, the database object described herein can be implemented as single databases, a distributed database, a collection of distributed databases, a database with redundant online or offline backups or other redundancies, etc., and might include a distributed database or storage network and associated processing intelligence.
[0050] FIG. 4 also illustrates environment 310 . However, in FIG. 4 elements of system 316 and various interconnections in an embodiment are further illustrated. FIG. 4 shows that user system 312 may include processor system 312 A, memory system 312 B, input system 312 C, and output system 312 D. FIG. 4 shows network 314 and system 316 . FIG. 4 also shows that system 316 may include tenant data storage 322 , tenant data 323 , system data storage 324 , system data 325 , User Interface (UI) 430 , Application Program Interface (API) 432 , PL/SOQL 434 , save routines 436 , application setup mechanism 438 , applications servers 400 1 - 400 N , system process space 402 , tenant process spaces 404 , tenant management process space 410 , tenant storage area 412 , user storage 414 , and application metadata 416 . In other embodiments, environment 310 may not have the same elements as those listed above and/or may have other elements instead of, or in addition to, those listed above.
[0051] User system 312 , network 314 , system 316 , tenant data storage 322 , and system data storage 324 were discussed above in FIG. 3 . Regarding user system 312 , processor system 312 A may be any combination of one or more processors. Memory system 312 B may be any combination of one or more memory devices, short term, and/or long term memory. Input system 312 C may be any combination of input devices, such as one or more keyboards, mice, trackballs, scanners, cameras, and/or interfaces to networks. Output system 312 D may be any combination of output devices, such as one or more monitors, printers, and/or interfaces to networks. As shown by FIG. 4 , system 316 may include a network interface 320 (of FIG. 3 ) implemented as a set of HTTP application servers 400 , an application platform 318 , tenant data storage 322 , and system data storage 324 . Also shown is system process space 402 , including individual tenant process spaces 404 and a tenant management process space 410 . Each application server 400 may be configured to tenant data storage 322 and the tenant data 323 therein, and system data storage 324 and the system data 325 therein to serve requests of user systems 312 . The tenant data 323 might be divided into individual tenant storage areas 412 , which can be either a physical arrangement and/or a logical arrangement of data. Within each tenant storage area 412 , user storage 414 and application metadata 416 might be similarly allocated for each user. For example, a copy of a user's most recently used (MRU) items might be stored to user storage 414 . Similarly, a copy of MRU items for an entire organization that is a tenant might be stored to tenant storage area 412 . A UI 430 provides a user interface and an API 432 provides an application programmer interface to system 316 resident processes to users and/or developers at user systems 312 . The tenant data and the system data may be stored in various databases, such as one or more Oracle™ databases.
[0052] Application platform 318 includes an application setup mechanism 438 that supports application developers' creation and management of applications, which may be saved as metadata into tenant data storage 322 by save routines 436 for execution by subscribers as one or more tenant process spaces 404 managed by tenant management process 410 for example. Invocations to such applications may be coded using PL/SOQL 434 that provides a programming language style interface extension to API 432 . A detailed description of some PL/SOQL language embodiments is discussed in commonly owned co-pending U.S. Provisional Patent Application 60/828,192 entitled, PROGRAMMING LANGUAGE METHOD AND SYSTEM FOR EXTENDING APIS TO EXECUTE IN CONJUNCTION WITH DATABASE APIS, by Craig Weissman, filed Oct. 4, 2006, which is incorporated in its entirety herein for all purposes. Invocations to applications may be detected by one or more system processes, which manages retrieving application metadata 416 for the subscriber making the invocation and executing the metadata as an application in a virtual machine.
[0053] Each application server 400 may be communicably coupled to database systems, e.g., having access to system data 325 and tenant data 323 , via a different network connection. For example, one application server 400 1 might be coupled via the network 314 (e.g., the Internet), another application server 400 N-1 might be coupled via a direct network link, and another application server 400 N might be coupled by yet a different network connection. Transfer Control Protocol and Internet Protocol (TCP/IP) are typical protocols for communicating between application servers 400 and the database system. However, it will be apparent to one skilled in the art that other transport protocols may be used to optimize the system depending on the network interconnect used.
[0054] In certain embodiments, each application server 400 is configured to handle requests for any user associated with any organization that is a tenant. Because it is desirable to be able to add and remove application servers from the server pool at any time for any reason, there is preferably no server affinity for a user and/or organization to a specific application server 400 . In one embodiment, therefore, an interface system implementing a load balancing function (e.g., an F5 Big-IP load balancer) is communicably coupled between the application servers 400 and the user systems 312 to distribute requests to the application servers 400 . In one embodiment, the load balancer uses a least connections algorithm to route user requests to the application servers 400 . Other examples of load balancing algorithms, such as round robin and observed response time, also can be used. For example, in certain embodiments, three consecutive requests from the same user could hit three different application servers 400 , and three requests from different users could hit the same application server 400 . In this manner, system 316 is multi-tenant, wherein system 316 handles storage of, and access to, different objects, data and applications across disparate users and organizations.
[0055] As an example of storage, one tenant might be a company that employs a sales force where each salesperson uses system 316 to manage their sales process. Thus, a user might maintain contact data, leads data, customer follow-up data, performance data, goals and progress data, etc., all applicable to that user's personal sales process (e.g., in tenant data storage 322 ). In an example of a MTS arrangement, since all of the data and the applications to access, view, modify, report, transmit, calculate, etc., can be maintained and accessed by a user system having nothing more than network access, the user can manage his or her sales efforts and cycles from any of many different user systems. For example, if a salesperson is visiting a customer and the customer has Internet access in their lobby, the salesperson can obtain critical updates as to that customer while waiting for the customer to arrive in the lobby.
[0056] While each user's data might be separate from other users' data regardless of the employers of each user, some data might be organization-wide data shared or accessible by a plurality of users or all of the users for a given organization that is a tenant. Thus, there might be some data structures managed by system 316 that are allocated at the tenant level while other data structures might be managed at the user level. Because an MTS might support multiple tenants including possible competitors, the MTS should have security protocols that keep data, applications, and application use separate. Also, because many tenants may opt for access to an MTS rather than maintain their own system, redundancy, up-time, and backup are additional functions that may be implemented in the MTS. In addition to user-specific data and tenant specific data, system 316 might also maintain system level data usable by multiple tenants or other data. Such system level data might include industry reports, news, postings, and the like that are sharable among tenants.
[0057] In certain embodiments, user systems 312 (which may be client systems) communicate with application servers 400 to request and update system-level and tenant-level data from system 316 that may require sending one or more queries to tenant data storage 322 and/or system data storage 324 . System 316 (e.g., an application server 400 in system 316 ) automatically generates one or more SQL statements (e.g., one or more SQL queries) that are designed to access the desired information. System data storage 324 may generate query plans to access the requested data from the database.
[0058] Each database can generally be viewed as a collection of objects, such as a set of logical tables, containing data fitted into predefined categories. A “table” is one representation of a data object, and may be used herein to simplify the conceptual description of objects and custom objects. It should be understood that “table” and “object” may be used interchangeably herein. Each table generally contains one or more data categories logically arranged as columns or fields in a viewable schema. Each row or record of a table contains an instance of data for each category defined by the fields. For example, a CRM database may include a table that describes a customer with fields for basic contact information such as name, address, phone number, fax number, etc. Another table might describe a purchase order, including fields for information such as customer, product, sale price, date, etc. In some multi-tenant database systems, standard entity tables might be provided for use by all tenants. For CRM database applications, such standard entities might include tables for Account, Contact, Lead, and Opportunity data, each containing pre-defined fields. It should be understood that the word “entity” may also be used interchangeably herein with “object” and “table”.
[0059] In some multi-tenant database systems, tenants may be allowed to create and store custom objects, or they may be allowed to customize standard entities or objects, for example by creating custom fields for standard objects, including custom index fields. U.S. patent application Ser. No. 10/817,161, filed Apr. 2, 2004, entitled “Custom Entities and Fields in a Multi-Tenant Database System”, and which is hereby incorporated herein by reference, teaches systems and methods for creating custom objects as well as customizing standard objects in a multi-tenant database system. In certain embodiments, for example, all custom entity data rows are stored in a single multi-tenant physical table, which may contain multiple logical tables per organization. It is transparent to customers that their multiple “tables” are in fact stored in one large table or that their data may be stored in the same table as the data of other customers.
[0060] While one or more implementations have been described by way of example and in terms of the specific embodiments, it is to be understood that one or more implementations are not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | In accordance with embodiments, there are provided mechanisms and methods for conditionally performing garbage collection. These mechanisms and methods for conditionally performing garbage collection can enable reduced application delay, improved data management efficiency, enhanced customer response, etc. | 6 |
This application claims benefit of Provisional application Ser. No. 60/052,193 filed Jul. 10, 1997.
BACKGROUND OF THE INVENTION
The present invention relates to an axle system particularly usable for skates, and especially for skates employing a disc-braking system.
Currently, in known roller skates employing a disc-braking system, the axles have a complex shape in order to both support the braking wheel and carry the components of the disc-braking system (U.S. Pat. Nos. 5,375,859, 5,401,038, 5,752,707). The axle sections adjacent to the wheel are shaped specifically to provide proper interaction of the braking system with the axles, effecting braking action on the wheel when so desired. Cylindrical portions of the axles, sized to standard wheel bearing inner diameters, pass through the wheel for support thereof.
When removal of the braking wheel is desired, these axle sections are unfastened and removed from the skate frame, allowing the wheel to be freed. However, all the disc-brake system components supported on the axles must also be removed from the axles to allow complete disassembly of the axles for wheel removal. This results in a complex, and potentially difficult, sequence of assembly steps just to replace the wheel. Parts may be lost or re-assembled incorrectly, resulting in frustrations to the user.
SUMMARY OF THE INVENTION
The design herein provides for easy removal of the braking wheel and brake components of an in-line skate disc-braking system. It allows for removal of the braking wheel, for replacement or service, without requiring complete disassembly of the axle from the skate frame. An easily removable central axle provides the primary support for the braking wheel. Since the outer axles carry the components of the disc-braking system, the design eliminates the problem of having these parts become disassembled when the braking wheel is removed. It does allow easy replacement of the disc-braking system components by removing a retainer from the outer axle half being serviced, without the need to disassemble the outer axles from the skate frame.
The design consists of an in-line roller skate, equipped with a boot, a frame, a plurality of wheels, and a disc-braking system. The design further consists of two outer axles attached to the frame, which each carry a brake disc, a lever arm, and a spring, which are components of a disc-braking system. A central axle passes through the outer axles to support the braking wheel. The outer axles have cylindrical and non-cylindrical sections for proper interaction with a disc-braking system. The central axle is removed to service the braking wheel while the outer axles remain fixed to the frame. Removal of a retainer on the outer axles allows for servicing of the components of the disc-braking system.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and characteristics of the invention will be described with reference to the accompanying drawings in which:
FIG. 1 is an exploded perspective view of the main components of the embodiment;
FIG. 2 is an exploded perspective view of a prior art axle for comparison purposes;
FIG. 3 is a side view of a skate embodying the invention in the normal skating position;
FIG. 4 is a partial cross sectional rear view of a braking wheel with the two disc brake embodiment of the invention in the normal skating position, taken in the direction of cutting plane 4--4 of FIG. 3;
FIG. 5 is a partial cross sectional rear view of a braking wheel with the single disc brake embodiment of the invention in the normal skating position, taken in the direction of cutting plane 5--5 of FIG. 3;
FIG. 6 is a side view of a skate embodying the invention, similar to FIG. 4, only showing the brake mechanism in the braking position;
FIG. 7 is a partial cross sectional rear view of a braking wheel with the two disc brake embodiment of the invention in the braking position and the brake mechanism engaged, taken in the direction of cutting plane 7--7 of FIG. 6;
FIG. 8 is a partial cross sectional rear view of a braking wheel with the single disc brake embodiment of the invention in the braking position and the brake mechanism engaged, taken in the direction of cutting plane 8--8 of FIG. 6;
FIG. 9 is an exploded perspective view of the components of the two-disc skate brake embodiment; and
FIG. 10 is an exploded perspective view, similar to FIG. 9, of the components of the single-disc skate brake embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 and FIG. 3, there are shown left and right axle halves 1 and 2, which include keying portions 3 and 9, circular portions 4, 7, 13, and 10, and noncircular portions 5 and 11. Circumferential grooves 6 and 12 are located on circular portions 7 and 13. Clearance holes 8 and 14 passing through the center of axle halves 1 and 2 are provided to allow insertion of central axle 15 through both axle halves 1 and 2. An axle fastener 17 secures the axle assembly 36 by installing into threaded portion 16 of central axle 15. The axle assembly 36 comprises the means for mechanical support of a disc braking mechanism as well as the means for easy replacement of braking wheel 34D and brake components as described herein.
Referring to FIG. 2, there are shown prior art left and right axle halves 18 and 19, which include keying portions 20, circular portions 21, 23, 27, and 29, and non-circular portions 22 and 28. Alignment pin 25 inserts into right axle half 19 and provides rigidity to the axle assembly. Mounting bolts 31 pass through mounting holes 24 and 30 to fasten the left and right axle halves 18 and 19 to a skate frame 33.
Referring now to FIG. 3, FIG. 4, and FIG. 9, there is shown an in-line roller skate, 32, which includes a shell 70, and a skate frame which supports a plurality of wheels, here shown as wheels 34A, 34B, 34C, and 34D. The wheels are rotatably mounted to the skate frame 33 by means of axles 35A, 35B, and central axle 17.
The braking wheel 34D, which is in the rearmost location in this embodiment, is mounted to the rear of the frame 33 by means of the central axle 15. This central axle is positioned inside clearance holes 8 and 14 of axle halves 1 and 2, and is secured to the frame 33 by installing and tightening the axle fastener 17. Axle halves 1 and 2 are located in the frame 33 by seating keying portions 3 and 9 into cutouts 57 and 58, and are secured to the frame by the clamping forces of the assembled central axle 15 and the axle fastener 17.
The braking wheel is mounted to the central axle by means of integral bearings 53, which fit between an axle bushing 51 and the wheel hub 52. Two brake discs 41 and 42 are mounted to the non-circular axle portions 5 and 11. These non-circular axle portions are shown having a generally rectangular cross-section. However, a triangular or other non-circular shaped cross-section is within the purview of the invention. The brake discs have cutouts 66 and 67 that fit over the non-circular axle portions 5 and 11, allowing the disc brakes 41 and 42 to slide axially along the axle halves. Brake pads 49 and 50, integral to braking wheel 34D, form annular rings concentric with the central axis of the wheel.
Springs 45 are mounted between the brake discs 41 and 42 and retainers 47 and 48. The springs provide a means for applying force to the brake discs, preventing the brake disc surfaces and the brake pads 49 and 50 from contacting each other during normal skating. The retainers 47 and 48 are located in circumferential grooves 6 and 12 allowing the springs 45 and brake discs 41 and 42 to remain with the axle assembly 36 after the central axle 15 and the braking wheel 34D have been removed. Lever arms 37 and 38 are mounted to the circular axle portions 4 and 10. The lever arms have non-circular cutouts 62 and 63 that match and fit over non-circular axle portions 5 and 11. The cutouts are provided for assembly purposes, so the lever arms 37 and 38 may slide over the non-circular axle portions 5 and 11 and be properly positioned on circular axle portions 5 and 11. Springs 46 attach to lever arm cutouts 64 and 65 and frame tabs 54 and 55, providing lever arm tension during normal skating.
Lever arm ramp surfaces 61 located on either side of lever cutouts 62 and 63 contact mating ramp surfaces 59 on the brake discs 41 and 42 during brake engagement. A bearing surface 39 located at the rear of lever arms 37 and 38 is attached thereto by means of fasteners 40. Washers 43 and 44 provide a wear-resistant surface against which lever arms 37 and 38 may bear during braking.
The function of the axle assembly in the aforementioned embodiment of the invention is as follows. Referring to FIGS. 6-7, when the skater desires braking, the skater rotates the skate 32 rearward about the rear wheel 34D, lever arms 37 and 38 are urged to the ground 56. Bearing surface 39 contacts the ground causing clockwise rotation of lever arms 37 and 38 about circular axle portions 4 and 10. The rotation of the lever arms causes the lever arm ramp surfaces 61 to engage the brake disc ramp surfaces 59. This contact causes the brake discs 41 and 42 to slide laterally along the non-circular axle portions 5 and 11 toward the brake pads 49 and 50.
The moment generated in the brake discs 41 and 42 by the lever arms 37 and 38 during braking is transferred to the non-circular axle portions 5 and 11. The moment is further be transmitted through the axle halves 1 and 2 to the skate frame 33. Axle keying portions 3 and 9 are seated snugly into frame cutouts 57 and 58 allowing the skate frame to absorb the moment and prevent the axle halves 1 and 2 from rotating.
The friction between the brake discs 41 and 42 and the brake pads 49 and 50 causes the rotation of the braking wheel 34D to slow or stop, which will slow or stop the skater. Referring now to FIGS. 3 and 4, when the skater wishes to resume normal skating, the skater lowers the toe of the skate which lifts the bearing surface 39 off the ground 56. This results in counter-clockwise rotation of the lever arms 37 and 38 allowing ramps 59 and 61 to disengage. The outward force imparted by springs 45 pushes the brake discs 41 and 42 away from the brake pads 49 and 50, allowing the braking wheel 34D to rotate freely.
Alternatively, it may be advantageous to provide braking with only one brake disc, which would provide sufficient braking force, yet reduce manufacturing costs for supply as a more economical embodiment.
FIGS. 5 and 10 illustrate this further embodiment of the invention where the wheel brake assembly comprises one brake disc 41. A spacer 68 provides proper lateral alignment of brake lever 38 mounted to circular axle portion 69 of a simplified axle half 71. FIG. 8 illustrates the single brake disc embodiment during brake engagement.
Referring to FIG. 4 and FIG. 9, when it is desired to replace the braking wheel 34D or any other components of the brake assembly, fastener 17 is removed and central axle 15 is extracted from the axle assembly 36. The skate frame 33 is molded to spring outward slightly when central axle 15 is extracted. This allows the braking wheel 34D with brake pad surfaces 49 and 50 to be removed by sliding wheel 34D out between axle halves 1 and 2. Since retainers 47 and 48 remain fastened to the axle halves 1 and 2, all additional brake components remain captive to the skate. Braking wheel replacement can thereby be performed without concern for loss of brake parts.
The frame 33 may also be molded in such a fashion so as not to spring outward when central axle 15 is extracted. In this embodiment, wheel removal is effected by simply spreading the frame 33 slightly, allowing the braking wheel 34D to be removed.
When it is desired to replace brake discs 41 and 42, brake levers 37 and 38, or other brake assembly components, retainers 47 and 48 are removed after removal of the braking wheel 34D. This allows all remaining brake assembly components to be removed or replaced.
Re-assembly of brake components is performed by first replacing all removed components captive to the axle halves 1 and 2. Retainers 47 and 48 are then installed. Braking wheel 34D is installed by sliding it between axle halves 1 and 2, inserting central axle 15, and securing the central axle with fastener 17. It should be understood that the axle assembly 36 may be used with a disc braking mechanism located in any of the wheel positions 34A, 34B, 34C, and 34D. The axle assembly 36 is shown being used with a disc braking system activated by ground contact. It should be understood that the axle assembly 36 may be used with a disc braking system with the lever arms 37 and 38 engaged by cuff activation or other means. | A quick-release axle system for in-line skates employing a disc-braking system providing easy removal of the braking wheel and brake system components for replacement or servicing. Two outer axles located on each side of a wheel provide support and activating means for the components of a disc-braking system. A central axle passing through the outer axles supports the braking wheel, allowing the wheel to rotate freely. Wheel removal is performed by removing the central axle from the outer axles, thus freeing the wheel. The outer axles, carrying components of the disc-braking device, remain attached to the skate frame. Removal of a retainer located on each of the outer axles, allows easy removal of the components of the disc-braking device attached thereto. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable
BACKGROUND OF THE INVENTION
This invention relates to a lifting valve including a bellows to seal a valve rod passage.
Lifting valves of the generic type preferably are designed as shut-off valves and are used according. At this point, at least one component of the aperture and closing motions of the closing component is directed perpendicularly to the end surfaces, the seating surfaces. The passage of the valve rod actuating the closing component through the valve box is spanned by a bellows which concentrically encircles the valve rod. This bellows which may be formed as an expansion bellows (DE 32 15 799 C2), a corrugated tube or a diaphragm (EP 0 508 658 B1) extends, as a rule, from the closing component up to that portion of the valve box which is traversed by the valve rod.
Such a valve rod sealing by means of a bellows has the advantage that there is no sealing gap between the valve rod adapted to slide in an axial direction and the stationary valve box, into which a product carry-over can take place because of the motion of the valve rod relative to the valve box. It is known that such sealing gaps pose sanitary problem zones in which germ or bacteria formation may occur, which will then provoke reinfections of the product in the valve box because of the valve rod motion, the so-called “elevator effect”.
Using a bellows to seal the passage of a valve rod is compulsory for high sanitary requirements especially in the aseptic range of the pharmaceutical chemical, or foodstoff-processing industries. From the aforementioned DE 32 15 799 C2, an aseptic valve has been known which has a closing component cooperating with a conical seating in a valve box with an appropriate annular sealing surface with the closing component being connected to a servo-drive via a screw and is joined to an expansion bellows coaxially encircling the screw and constituting the screw seating which, at its free end, has a connecting flange adapted to be locked in place between the valve box proper and a valve lantern with a conical sealing surface which bears against a complementary annular seating surface of the box surface which bears against a complementary annular seating surface of the box where the closing piece, the expansion bellows, and its connecting flange form a rotation-symmetrical replacement unit which is exchangeable as a whole and is open to the top. This so-called replacement unit is made of a polytetrafluoroethylene material (PTFE such as Teflon) which, as positive properties, exhibits high elasticity, resistance to chemicals, and a long service life while putting up with relatively large plastic ductility (heavy propension to “flow” or “creep”).
The aforementioned replacement unit, amongst other things, has the two problem zones which now are indicated.
1. The connecting flange, along with its conical sealing surface, defines a sensible annular gap in an interaction with its complementary annular seating surface in the valve box. In order that this annular gap between the connecting flange and the stationary valve box parts bordering it on the other side permanently remain tight and do not “work” under varying conditions of operation (pressure and temperature) the connecting flange is squeezed between the valve box and a box closing component (box top), i.e. the connecting flange is kept under a bias in its locked position. It is known now that the material preferably used for the replacement unit at the beginning (PTFE) tends to exhibit a certain creep behaviour under varying pressures and temperatures, as seen over a prolonged period of time, which causes the shape of the connecting flange to slightly change. In operation, this causes the bias which prevents an expansion of the sealing gap and is produced by the squeezing action to gradually diminish and the sealing gap to “work”. This might cause a product to penetrate in the “breathing” sealing gap with the aforementioned consequences of product carry-over and subsequent reinfection.
2. The expansion bellows which has been known from DE 32 15 799 C2 is an integral part of the so-called replacement unit which may be exchanged in the valve, if required. To this end, it is necessary that the box aperture and, hence, the measure of the connecting flange which corresponds thereto be designed at least as large as the outer diameter of the closing component. As is shown in FIG. 2 of the aforementioned document the tensile forces acting onto the connecting flange if the expansion bellows is under a tensile stress and the reaction forces directed counter to these forces are not situated on a joint line of action at the locking point of the connecting flange, but are at a radial spacing from each other. This spacing and, hence, the bending moment produced by this couple of forces will even be increased, as a rule, because efforts are made to dimension the expansion bellows so as to be as small as possible for reasons of strength. This causes the point of application of the tensile force exerted by the expansion bellows onto the connecting flange to migrate further inwardly in a radial direction so that the aforementioned radial spacing between the two forces and, therefore, the bending moment will continue to increase.
The bending moment just discussed will now lead to the fact that the connecting flange squeezed between the box and the box closing component apart from being subjected to this squeezing stress, also experiences a bending stress which provokes an increased strain on the material and, hence, an intensified change in shape in this region. This aggravates the critical situation previously described with reference to the sealing gap under item 1.
In the document EP 0 508 658 B1 also mentioned at the beginning, in which an aseptic valve construction is described with a bellows of the generic type, the aforementioned problem existing in the region of the critical sealing gap on the conical sealing surface of the connecting flange was discussed as a subject already. To mitigate the problem encountered, a suggestion is made there that the complementary annular shoulder seating in the valve box which corresponds to the conical sealing surface of the connecting flange in the valve box should have a lip completely inside which is inclined downwardly from the inwardly and upwardly inclined annular surface of the valve box. Such a measure may possibly prevent the sealing gap from being expanded prematurely. However, it constitutes no long-lasting measure because if the bellows material creeps at this point the bias required will diminish as well and will not be permanently ensured by any further recognizable measures.
A satisfactory solution to this problem may be successful only if the influencing factors which were described as being adverse under items 1 and 2 above can be reduced and/or if they can be counteracted by appropriate measures.
The expansion bellows which has been known from DE 32 15 799 C2 encircles the valve rod at a relatively large radial clearance. Although the latter allows a view into and makes possible an intervention in the interior of the bellows in case of need and, thus, possibly favours a detection of a bellows defect on time it is rather infavourable with respect to the stability of the bellows because of an attack of the flow and squeezing forces from the space enclosing the bellows. A conditional remedy may be provided here either by decreasing the bellows diameter in the region of the bellows folds or increasing the rod diameter. The first action, however, leads to a larger stress on the box-end connecting flange of the expansion bellows at a bending moment, which stresses the critical gap between the conical sealing surface of the connecting flange and its complementary annular seating surface in the box in a dynamically alternating way. As a result of the existing propension of the bellows material to flow at a high product pressure and/or high product temperature, there is a risk of gap expansion and product penetration into this region with all of the adverse consequences known, amongst which are germ formation and product reinfection.
Leaving out attention to the aforementioned gap problems in the region of the connecting flange for a moment and directing attention exclusively to an increase in bellows stability in the region of the bellows folds such increase may be obtained by a decrease in the break between the bellows folds and the valve rod, either by reducing the bellows diameter or, if the bellows diameter is not changed, by a supporting action from the inside, e.g. by increasing the rod diameter or by retracting the supporting tube which tightly borders the bellows (DE 42 43 111 A1).
A supporting action from the inside has shown that if bellows materials are used which have a strong propension to undergo durable deformation, so-called “creeping”, when under a stress, such as polytetrafluoroethylene, the bellows fold regions adjoining the rod come to increasingly bear against the rod or the supporting pipe because of this permanent deformation so that the respective fold interior which is bordered by the bellows fold, on one hand, and the rod or supporting pipe itself in the inside region, on the other, defines a self-contained cavern from which the medium enclosed therein cannot or can insufficiently escape. The medium enclosed can either be a check medium with which the interior of the bellows is filled and which can be detected via suitable devices, or leaking media which enter the interior of the bellows and result from a defect in the bellows (e.g. a product). This puts in question any dependable and up-to-date indication of a bellows defect or its instant detection.
As a result of the axial shift of the rod, there is a relative motion between the expansion bellows and the rod, which approaches the zero at the point connecting the bellows to the rod and has its maximum rate at the box-side end of the bellows. As the bellows folds bear against the rod this relative motion is impeded because there is a friction between the bellows fold and the rod, This can go so far that the latter does not occur at all in regions of a small relative motion and it is only the bellows folds in the vicinity of the box-side connection of the bellows which perform the entire shifting motion of the rod. As a result, stresses higher than those on which the design was based will occur in this region with the possible consequence being a premature rupture of the bellows and, thus, a reduction in the service life of the bellows.
It is the object of the present invention to ensure for a lifting valve a reliable, hygienically proper, and durable static sealing of the connecting flange of the closing-member unit in the valve box under the occurring forces at an adequately long service life. In addition, a reliable indication of a bellows defect is intended to be ensured throughout the full service life of the bellows even for a bellows which tightly encircles the valve rod.
BRIEF SUMMARY OF THE INVENTION
The first measure consists in that the forces resulting from the valve-lift induced deformation of the bellows and/or the respective pressure in the box are absorbed where they are produced initially. An absorption free from bending moments of these forces is achieved in the proposed solution by the fact that the connecting flange of the closing-member unit, in the region of its connection to the bellows, has a fastening component indirectly supported on the box side which transmits the resultant forces from the bellows and the connecting flange into the box via the shortest path possible. This avoids the transmission of these forces. which has been necessary hitherto, as transverse forces through the connecting flange radially extending outwardly to the locking point in the region of which there are the conical sealing surface and the critical sealing gap. A bending moment applying a stress to the scaling gap does not virtually occur in the proposed solution. The fastening component which is proposed absorbs axial forces which are provoked, for example, by stretching the bellows into the closing position of the lifting valve or by negative pressures acting in the interior of the box against the environment of the lifting valve.
The second inventive measure consists in that the connecting flange, in the region of its conical sealing surface, is reduced to a minimal wall thickness meeting the strength-related requirements in the form of a diaphragm-shaped sealing element. This measure avoids the buildup of the ductile bellows material in the critical sealing region.
In order that the required bias and, hence, the required sealing contact with the complementary annular seating surface in the valve box, be maintained in the region of the diaphragm-shaped sealing element the proposed invention further provides that the diaphragm-shaped sealing element, on its side facing away from the conical sealing surface, has at least one biased elastic thrust ring which presses the sealing surface onto the complementary annular seating surface. The elastic thrust ring virtually acts like a spring which persistently keeps the conical sealing surface under a bias even in the event of the sealing material creeping in this point and, thus, reliably prevents the sealing gap from expanding with the drawbacks previously described involved.
An advantageous aspect of the bellows provides that the diaphragm-shaped sealing element in the form of a prolongation oriented towards the complementary annular seating surface is formed on a closing plate of the connecting flange, the closing plate radially originating from the inside of the bellows and radially extending outwardly, substantially in the form of a disk, in a plane perpendicular to the axis of the valve rod. Acting on the diaphragm-shaped sealing element formed in such a material-saving way is the biased elastic thrust ring. A “creep” of the bellows material in this region may be compensated, without any loss in sealing force, by the biased elastic thrust ring.
In order to definedly fix and support the diaphragm-shaped sealing element and the closing plate of the connecting flange in the box another embodiment provides for a supporting body which is accommodated in an upper box aperture of the box coaxially to the valve rod and is axially supported towards the interior of the box on a stop surface adjoining the upper box aperture and is also supported indirectly or directly in the opposed direction. In addition, the supporting body receives and partially encircles the thrust ring in a groove-shaped recess adjacent to the surface area of the upper box aperture. This measure and the aforementioned stop of the supporting body in the box ensure a defined bias of the thrust ring and, thus, a defined contact pressure of the diaphragm-shaped sealing element on the complementary annular seating surface in the box.
In addition, the supporting body assumes the task of supporting the closing plate of the connecting flange under forces acting from the inside to the outside. To this end, the closing plate and the supporting body are formed to be complementary to each other. If a force acts from the outside to the inside, e.g. because of a negative pressure in the box as against the environment of the lifting valve, the fastening component is supported, via a preferably positive-fit connection, on the side of the supporting body facing away from the closing plate.
In order to prevent the diaphragm-shaped sealing element from slipping out of its locked position between the annular seating surface in the box and the elastic thrust ring another aspect of the bellows provides that the prolongation of the diaphragm-shaped sealing element lengthens to become an annular collar extending towards the valve rod and widens to form a wedge and that the collar is accommodated between the supporting ring and the surface area of the upper box aperture.
Another aspect of the bellows proposes that the collar, as seen in the axial direction, should be applied to at the end side by an elastic thrust ring which is squeezed by the supporting ring in conjunction with the surface area of the upper box aperture. This measure causes the collar to be keyed in place between the supporting ring and the surface area of the upper box aperture.
In order to ensure that any leakages that might occur after all be discovered and that reinfections ensuing therefrom be avoided another aspect of the bellows according to the invention provides that a leakage cavity annularly encircling the collar should be formed in the surface area of the upper box aperture, which cavity is connected to the environment of the lifting valve via at least one joining duct.
A further embodiment forming an aspect of the fundamental inventive features of the proposed bellows provides that the diaphragm-shaped sealing element should be formed by the fact that a continuous groove engages and constricts the connecting flange on the side facing away from the sealing surface, and that the groove should receive at least one thrust ring which is adapted to be squeezed in the groove by means of a continuous thrust edge on a box top portion traversed by the valve rod.
In order to reduce local stresses inside the permanently elastic thrust ring an advantageous embodiment further provides that the thrust edge should be flanked on either side by a continuous annular balancing chamber each which directly widen the space defined by the groove.
For reasons of strength, efforts are made to configure the bellows as small as possible in diameter. In order to stabilize the bellows additionally, an advantageous aspect provides that this one and the fastening component joining it should be fitted, at the inside, with a valve rod bore which encircles the valve rod at a minimal play ensuring its functionality. This aspect causes the valve rod to impart an additionally stabilizing effect onto the bellows and the fastening component from inside.
With regard to the anchoring of the fastening component, the invention provides both embodiments releasable with no damage involved and embodiments releasable with a damage involved. In this context, all sufficiently known non-positive and/or positive forms of anchoring can be realized.
A particularly advantageous aspect which releasably anchors the fastening component in the top of the box releasably, on one hand, and in a positive-fit and non-positive fit connection, on the other, is provided if the fastening component is screwed into the top of the box by means of a screw thread, preferably an acme thread.
Another option of anchoring the fastening component in the top of the box is to provide a locked joint, i.e. a non-positive fit connection.
If a damage to or a destruction of the closing-member unit is considered acceptable or even desirable while it is being replaced in the aseptic lifting valve another aspect provides that the fastening component should be anchored by a hook-shaped or barb-shaped positive-fit connection in the top of the box. Such a solution is very cost-effective, as a rule. At this point, an assembly of the closing-member unit in the valve is very easy and poses no problems, but its disassembly is feasible, as a rule, only by damaging or destroying the closing-member unit, especially in the region of the fastening component. In this context, the suggestion is that the fastening component should be formed on the closing-plate side facing away from the bellows in the shape of several drawhooks which preferably are spaced uniformly across the circumference of the closing plate and concentrically encircle the valve rod and which back up their free hook-shaped ends on a supporting surface defined by an annular recess in the top of the box.
The proposed reinforcement durably supports the bellows fold region adjoining the rod and, thus, will prevent this area from bearing against the rod because of its flow. As a result, the relatively narrow gap will be maintained between the supported bellows fold and the rod, which causes the propping function of the rod to be provided as before and the stability of the bellows to be acted on in a way which is favourable in all.
According to a favourable aspect, a durable support of the bellows and, specifically, the bellow folds is achieved by the fact that the reinforcement consists of a material which is temperature-resistant, is of a low plastic ductility and has a low coefficient of friction towards the material of the rod. These imperative properties which include positive properties (temperature resistance and low coefficient of friction towards the material of the rod) which, as a rule is employed for the bellows (polytetrafluoroethylene), on one hand, and the decisive drawback of the bellows material, namely its relatively large plastic ductility, on the other narrow down the materials to be considered for the reinforcement. It is primarily metallic and ceramic materials and temperature-resistant plastic materials which are employed here.
In order to join the reinforcement to the bellows material in a relatively simple way in the course of the manufacturing process the suggestion is that the reinforcement should border the bellows fold from inside.
The possible ways suggested for connection between the material of the bellows and the material of the reinforcement either are a material-fit connection or a positive-fit and/or non-positive fit connection.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Embodiments of the invention are shown in the drawing and are now briefly described. In the drawings,
FIG. 1 shows a central section extending below the servo-drive through a lifting valve having a bellows of the generic type in conjunction with a connecting flange in a first embodiment;
FIG. 2 shows a central section through a closing-member unit above the valve seat having a bellows of the generic type in conjunction with a connecting flange in a second embodiment;
FIG. 3 shows an enlarged representation of a central section through the connecting flange of first embodiment in a region marked by the detail “X” in FIG. 1;
FIG. 4 also shows an enlarged representation of a central section through the connecting flange of the first embodiment according to FIG. 3 where the prolongation of the diaphragm-shaped sealing element lengthens to form a annular collar extending towards the valve rod region and, thus expands to form a wedge;
FIG. 5 also shows a central section through the closing-member unit of FIG. 2 for itself alone and in an enlarged representation;
FIG. 6, in a very enlarged representation, shows a central section through the continuous groove, the continuous thrust edge at the top of the box, and the elastic thrust ring squeezed between the two components in a region marked by the detail “Z” in FIG. 2;
FIG. 7 shows a central section through the fastening component of the connecting flange at the point marked by the detail “Y” in FIG. 2 wherein the features of a solution differing from the aspect of Figure are illustrated in this region; and
FIG. 8 shows a central section through the closing-member unit in one of the two fundamental embodiments with a reinforcement provided in the bellows region adjoining the rod.
DETAILED DESCRIPTION OF THE INVENTION
While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated.
A lifting valve 1 (FIG. 1) has a box 1 a which, as referred to the position illustrated, is provided with a lateral box connection 1 b and a downwardly facing box connection 1 l . The latter connects the interior of the box 1 a , via a lower box aperture 1 c , to another box portion (not shown) which is flanged below to the box 1 a in case of need. Formed in the region where the box 1 a transits to the lower box aperture 1 c is a seating surface 1 e which preferably is conical and faces the interior and interacts with an appropriate closing component 4 a . The latter is rigidly connected to a valve rod 6 which is passed upwardly through the box 1 a and a lantern 12 joining it and ends in a servo-drive 13 connected to the latter. The valve rod 6 is concentrically encircled by a bellows 4 , a so-called expansion bellows, or even a so-called corrugated tube or a diaphragm as is known from EP 0 508 658 B1, each of these sealing elements which preferably are expandable in an axial direction being fastened, in a material-fit connection, to the closing component 4 a , on one hand, and the connecting flange 40 , on the other. The latter, amongst other things, comprises a closing plate 4 c which has a protrusion which essentially is in the form of a disk and is oriented in a plane perpendicular to the axis of the valve rod 6 and radially extends from the inside of the bellows 4 b , and which radially extends outwardly to a degree such as to allow, in conjunction with a corresponding upper box aperture 1 d , the disassembly of a closing-member unit 4 which, apart from the connecting flange 40 , consists of the closing component 4 a and the bellows 4 b , in an upward direction.
The disk-shaped closing plate 4 c is radially reduced at the outside to a minimal wall thickness meeting the strength-related requirements in the form of a diaphragm-shaped sealing element 4 l (cf. the enlarged representation shown in FIG. 3 of the region marked by the detail “X” in FIG. 1 ). The diaphragm-shaped sealing element 4 l is formed in the shape of a prolongation oriented towards a complementary annular seating surface 1 k (cf. especially FIG. 3) on the closing plate 4 c in the box 1 a and has a conical seating surface 4 h cooperating with the annular seating surface 1 k . The latter is pressed onto the complementary annular seating surface 1 k via a biased elastic thrust ring 5 which is disposed on the side facing away from the conical seating surface 4 h of the diaphragm-shaped sealing element 4 l . The elastic thrust ring 5 is received by a groove-shaped recess 30 a in a supporting body 30 and is enclosed, in an interaction with the surface area of the upper box aperture 1 d , leaving out only that portion which is in contact with the diaphragm-shaped sealing element 4 l . The supporting body 30 is received coaxially to the valve rod 6 in the upper box aperture 1 d of the box 1 a , and it axially bears towards the interior of the box 1 a via a first supporting surface 30 b on a stop surface 1 f adjoining the upper box aperture 1 d.
Thus, if the system is in a stressed condition the elastic thrust ring undergoes a defined bias with the metallic stop of the locking component, the supporting body 30 . The supporting body 30 is embedded and bears against the stop surface 1 f via a lantern flange 12 a of the lantern 12 which is received and coaxially centered inside a box flange 1 g . The positive-fit and non-positive fit embedding of the lantern flange 12 in the box flange 1 g is performed by a locking flange 10 , which is squeezed with the box flange 1 g by means of a connecting element 11 e.g. a so-called tip-up ring. The supporting ring 30 , proceeding from the recess 30 a and as referred to its further range of radial extension, has a second supporting surface 30 c which supports the complementary closing plate 4 c with its first supporting surface 4 m from outside as seen in an axial direction. This enables forces acting to the outside from the interior of the box 1 a to be absorbed by the supporting body 12 and to be abducted into the box flange 1 g and, thus, into the box 1 a via the lantern flange 12 a , the locking flange 10 , and the connecting element 11 . If the closing plate 4 c is stressed in an inverse direction, i.e. to the inside from the outside, e.g. by stretching the bellows 4 b into the closing position of the lifting, valve 1 or as a consequence of negative-pressure build-up in the interior of the box 1 a , the forces resulting therefrom are transmitted from the fastening component 4 f , via a securing element 9 engaging the latter in a positive-fit connection, to the supporting body 30 which if this direction of stress exists is supported onto the stop surface 1 f on the box 1 a directly via its first supporting surface 30 b . To this end, the fastening component 4 f has provided in it a securing groove 4 o which rests on the securing ring 9 by a second supporting area 4 p.
The closing component 4 a (FIG. 1) has embedded in it a securing insert 7 which comprises a disk-shaped fastening plate 7 a which radially extends far outwardly and a centric fastening socket 7 b . The valve rod 6 is screwed into the fastening socket 7 b by means of a threaded pin 6 a.
In order to be sure that the diaphragm-shaped sealing element 4 l is prevented from being torn out of its locked position between the annular seating surface 1 k and the thrust ring 5 even in case of very extreme stresses a further development of the above described arrangement of FIG. 3 provides that the prolongation of the diaphragm-shaped sealing element 4 l should lengthen to form a annular collar 4 g extending towards the valve rod 6 (FIG. 4) while expanding so as to form a wedge, and that the collar 4 g should be received between the supporting ring 30 and the surface area of the upper box aperture 1 d . Thus, the collar 4 g is of a wedge-like shape in its lower region so that if the diaphragm-shaped sealing element 4 l is under a tensile stress directed towards the interior the collar 4 g connected thereto is keyed between an annular recess 30 d in the supporting body 30 , which ends in a wedge-shaped surface 4 h and the opposed surface area of the upper box aperture 1 d . The wedge-shaped surface 4 q is formed on a projection 30 e which borders a part of the groove-shaped recess 30 a for the elastic thrust ring 5 .
In order that the collar 4 g be biased and keyed in place already in a condition free from operating forces in its environment embedding it is further provided that it should be applied to, at its end side as seen in an axial direction, by an elastic thrust ring 5 * which is squeezed in place by the supporting ring 30 in conjunction with the surface area of the upper box aperture 1 d (FIG. 4 ).
With a view to supervising and possibly removing leaks from the region between the diaphragm-shaped sealing element 4 l and the elastic thrust ring 5 * each of which is in a sealing contact with the annular seating surface 1 k or the surface area of the upper box aperture 1 d another suggestion provides that a leakage cavity 1 h enclosing the collar 4 g preferably in the form of a ring should be formed in the surface area of the upper box aperture 1 d , which cavity is connected to the environment of the lifting valve 1 via at least one joining duct 1 i.
FIG. 2 shows a lifting valve 1 which only is illustrated in part with the connecting flange 40 configured in a second fundamental embodiment. In contrast to the lifting valve 1 of FIG. 1, a lower box aperture 1 c has sealingly inserted in it a seating ring 2 which connects the interior of the box 1 a to a box portion flanged below to the box 1 a in case of need via a communicating aperture 2 b . The seating ring 2 has a seating surface 2 a which preferably is conical and is directed to the interior of the box 1 a and which cooperates with the closing component 4 a . The rest of the structure of the lifting valve 1 is substantially identical to the one of FIG. 1 except for the shape of the connecting flange 40 which is described below and its way of embedding into the box 1 a.
The first invention idea of the present invention refers to the region marked as the detail “Z” (FIG. 2) which is shown more distinctly in FIG. 6 . Since a gradual variation in the shape of the connecting flange 40 defining a gap S with the box 1 a has been unavoidable till this date in the region of its conical sealing surface 4 h has been unavoidable hitherto under changing conditions of operation (pressure, temperature) for the material (PTFE) which is employed, as a rule, in designs according to the state of the art the diaphragm-shaped sealing element 4 l formed on the connecting flange 40 at the outside radial end of the closing plate 4 c (FIG. 5) is configured by causing a continuous groove 4 c to engage and constrict the connecting flange 40 on the side facing away from the sealing surface 4 h . The groove 4 e accommodates at least one thrust ring 5 which, by means of a continuous thrust edge 3 c (FIG. 6 ), is squeezed on a box portion 3 traversed by the valve rod 6 in the groove 4 e.
The connecting flange 40 (FIG. 5) which is constricted to a minimal wall thickness meeting the strength-related requirements in the region of the conical sealing surface 4 h via the groove 4 e consists of a collar 4 g extending towards the axis of the valve rod 6 which connects the substantially disk-shaped closing plate 4 c oriented in a plane perpendicular to the axis of the valve rod and radially extending from the inside of the bellows 4 b to a annular flange projection 4 d disposed at the end of the connecting flange 40 . The engagement of the groove 4 e appropriately is so profound that the region which is left is made so thin as is just possible for reasons of safety.
As a consequence of the squeeze provoked by the thrust edge 3 c , the permanently elastic thrust ring 5 A is bulged out into a first and a second annular balancing chamber 3 a and 3 b , respectively, as is provided by an advantageous aspect (FIG. 6 ). The latter serve for reducing local stresses inside the permanently elastic thrust ring 5 in this region. A respective escaping motion of the thrust ring 5 as a consequence of a change in volume and a deformation will be ensured by the balancing space designated 14 there in the embodiment of FIGS. 3 and 4.
The permanently elastic thrust ring 5 (FIGS. 2, 5 , 6 ), using its ability to reversibly change its shape, compensates the comparatively small deformations of the annular flange projection 4 d and the adjoining collar 4 g and, partially, even those of the closing plate 4 c in this region, and it almost acts like an independently acting resetting device to permanently ensure the sealing action to conform to aseptic conditions between the conical sealing area 4 h and the adjoining complementary annular seating surface 1 k of the box 1 a . As far as a durable bias of the diaphragm-shaped sealing element 4 l is concerned on the associated annular seating surface 1 k the mechanisms of action correspond to those of the first embodiment of FIGS. 1, 3 , and 4 .
If it proves to be opportune or necessary several of the aforementioned permanently elastic thrust rings 5 are disposed to permanently ensure the bias in the region of the continuous groove 4 a as spread over the critical range.
The second idea of the invention as was addressed above is apparent from the region designated by the detail “Y” in FIG. 2 . This detail “Y” is also shown in an enlarged representation in FIG. 5 . To avoid a bending moment resulting from a couple of forces which is formed, for example, by a tensile force in the bellows 4 b and the corresponding force of reaction in the region of the closing plate 4 c the whole connecting flange 40 of the closing-member unit 4 is provided with a fastening component 4 f anchored in the box top 3 in the region where it is connected to the bellows 4 b . In the embodiment shown, the fastening component 4 f is provided, at its outside, with a screw thread 4 n , preferably an acme thread, via which a non-positive fit and a positive-fit connection is possible with the box top 3 . This allows the tensile forces exerted by the expansion bellows 4 b onto the closing plate 4 c to be introduced directly into the box top 3 and to be absorbed there with no formation of a bending moment influencing the critical sealing gap S.
The bellows and the adjacent fastening component 41 are provided, at their inside, with a valve rod bore 4 k which encircles the valve rod 6 at a minimal clearance ensuring, its functionality. This aspect gives the bellows 4 b and the fastening component 4 f additional stability from inside. An appropriate aspect within the scope of the first embodiment of the proposed invention is shown in FIG. 1 . The bellows 4 b (see the illustration on the right of the valve rod 6 ) is supported by a supporting component 60 * here whereas the illustration on the left of the valve rod 6 shows a supporting component 60 which is encircled by the bellows 4 b at a relative large clearance.
Another aspect in this range provides (FIG. 7) that the fastening component 4 f should be configured in the form of several drawhooks which preferably are spaced across the circumference of the closing plate 4 c and concentrically encircle the valve rod 6 . The drawhooks 4 f are formed like hooks at their free end and are supported on a supporting surface 3 e which is defined by a recess 3 f in the box top 3 . In a favourable aspect, several of these drawhooks 4 f are constituted by a cylinder-shaped elongation which extends on the side of the closing plate 4 c which faces away from the bellows 4 b . To make it possible to mount the closing plate 4 c , in connection with the drawhook 4 f , in an internal bore 3 d in the box top 3 , the cylinder-shaped continuation part constituting the drawhooks 4 f is slotted at several points, preferably at equal spacings. After the drawhooks 4 f are introduced into the recess 3 f they are retained there by the valve rod 6 in their anchored position. Tensile forces provoked by a bellows 4 b stretching in the closing position of the lifting valve 1 are now transmitted directly onto the box top 3 via the drawhooks 4 f and the supporting surface 3 e and are supported there so that no flexural stress occurs on the closing plate 4 c with the concomitant consequences for the sealing gap S.
The above described effects and advantages of the drawhooks 4 f are equally achieved if the closing-member unit configuration is according to the FIGS. 2 and 5 (positive-fit and non-positive-fit connection by means of a screw thread). In addition, other force transmissions are also possible, it having to be ensured in any other case that the tensile forces exerted by the bellows 4 b while it is lengthened or the forces resulting from the respective pressure in the box (such as forces resulting from the negative pressure as against the ambient pressure of the lifting valve) are directly introduced into the box top 3 . This can also be accomplished by means of barbs, other positive-fit connections such as the locking ring 9 in the complementary locking groove 4 o (cf. FIGS. 1, 3 , and 4 ) or an appropriate non-positive fit locking of the closing plate 4 c in this region rather than by the above described bolted joint 4 f of drawhooks.
If the possible fastening of the closing plate 4 c in the above mentioned region is designed as a positive-fit connection there are two alternative options here again. The positive-fit connection may be designed as being releasable with no damage involved, on one hand, or as being releasable with a damage involved, on the other. In those instances where this destruction can be or will be put up with as planned if the closing-member unit 4 is exchanged the fastening can be designed, for example, as a non-releasable snap connection which will also be destroyed during the disassembly of the closing-member unit 4 . In all of the other instances, this snap connection will be designed as being releasable. A glance at the configuration of the lifting valve of FIG. 1 shows that the closing-member unit 4 if drawhooks 4 f are provided in the region concerned can be disassembled with no destruction involved if the valve rod 6 is initially removed from the valve-rod bore 4 k of the closing-member unit 4 and the adjoining drawhook 4 f is removed subsequently. Thereupon, the drawhooks 4 f may be radially bent inwardly and may be removed from the bore 3 d in the box top 3 . If the fastening component 4 f is configured in the form of a releasable bolted joint it will be no problem to disassemble it.
FIG. 8 shows the closing-member unit 4 which was already described previously and, in its central portion comprises the bellows 4 b which, at its end sides, is connected to a box-end connecting flange 40 each, on one hand, and the closing component 4 a , on the other. The bellows 4 b itself comprises a multiplicity of convex-shaped and concave-shaped bellows folds 40 b which alternately are lined up in this configuration with each convex-bulged bellows fold 40 b as referred to the bellows interior defining a cavity H. The closing-member unit 4 is coaxially traversed by the valve rod 6 which runs to end in a threaded pin 6 a and, along with it, is screwed into the fastening socket 7 b with the latter, like the fastening plate 7 a , is embedded in a recess 4 i in the closing component 4 a (see also FIG. 5 ).
According to the invention, the suggestion is to provide an annular reinforcement 8 or 8 * durably supporting this region in the region adjoining a bellows fold 40 b . In the embodiment, the reinforcement 8 or 8 * borders the bellows fold 40 b from the inside. In the embodiment, the connection may then be realized as a material fit or a non-positive fit.
As far as the respective annular reinforcements 8 , in this shape, are connected to the respective bellows fold 40 b or are inserted in the material of the bellows fold or are moved to this one the reinforcements in question are given the reference number 8 .
The above Examples and disclosure are intended to be illustrative and not exhaustive. These examples and description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the attached claims. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims attached hereto. | The invention relates to a bellows to seal a valve rod passage in a lifting valve, specifically formed as an expansion bellows or corrugated tube, which ensures a reliable, hygienically proper and durable static sealing of the connecting flange of a closing-member unit in the box of the lifting valve under the occurring forces at an adequately long service life. This is achieved by the fact that the connecting flange ( 40 ) of the closing-member unit ( 4 ), in the region where it is connected to the bellows ( 4 b ), has a fastening component ( 4 f ) indirectly supported on the box side to absorb, in a way free from bending moments to a very large extent, the forces resulting from the valve-lift induced deformation of the bellows ( 4 b ) and/or the respective pressure in the box ( 1 a ) and is reduced, in the area of its conical sealing surface ( 4 h ), to a minimal wall thickness meeting the strength-related requirements, in the form of a diaphragm-shaped sealing element ( 4 l ), and that the diaphragm-shaped sealing element ( 4 l ), on its side facing away from the conical scaling surface ( 4 h ) has at least one biased elastic thrust ring ( 5 ) which presses the sealing surface ( 4 h ) onto the complementary annular seating surface ( 1 k ). | 5 |
BACKGROUND
1. Field of the Invention
The present invention relates generally to an assay for a ligand. More particularly, the invention relates to the use of monoclonal antibodies in an assay for L-thyroxine.
2. Description of the Prior Art
Immunologically based diagnostic assays have traditionally used mixtures of antibodies, referred to herein as polyclonal antibodies. Polyclonal antibodies are elaborated in animals by B-lymphocytes in response to the challenge of an antigen, such as a toxin, bacteria, virus or a foreign cell, which invades or is introduced into the animal. Antigens have one or more surface markers, or determinants, which are recognized as foreign by the lymphocytes.
A given lymphocyte recognizes only one determinant of the antigen, and elaborates only a single antibody. The antibody which it elaborates is specific only for an antigen having that determinant. However, most antigens have many determinants, and other lymphocytes will produce antibodies against each of these determinants. In addition, since the number of antigens is unlimited, the individual will likely possess antibodies from previous antigenic challenges. As a result, the individual will possess in its serum a large pool of different, or polyclonal, antibodies.
Known antisera are based on polyclonal antibodies. Even after many isolation and purification steps, polyclonal antibodies are still heterogeneous. Such heterogeneity may limit the specificity of the antiserum and thereby reduce its effectiveness as an immunological reagent, such as a diagnostic reagent.
Monoclonal antibodies are homogeneous and thereby eliminate many of the problems associated with conventional antisera based on polyclonal antibodies. In the preparation of monoclonal antibodies, a mouse is typically injected with the antigen (the immunization step), and, after a period of time, antibody-making lymphocytes are isolated, usually from the spleen. The lymphocytes are fused with myeloma cells to provide fused cells, referred to as hybridomas. The hybridomas are separated from unfused lymphocytes and myeloma cells. Specific hybridomas are isolated and tested to establish that the isolated hybridoma does indeed produce antibody specific for the antigen used in the immunization step. The hybridoma so produced combines the ability of the parent lymphyocyte cell to produce a specific single antibody with the ability of its parent myeloma cell to continually grow and divide, either in vitro as a cell culture or in vivo as a tumor after injection into the peritoneal cavity of an animal.
Monoclonal antibodies possess several advantages over polyclonal antibodies. They are produced by a single hybridoma cell line and are thus absolutely homogeneous. The antigen used in the immunization step does not have to be pure. Monoclonal antibodies are produced by a hybridoma which can grow indefinitely in cell culture or in an animal. Monoclonal antibodies can be obtained in almost unlimited quantity, and the supply is not limited to the lifetime of a producing animal.
Haptens are low molecular weight non-protein substances which are capable of interacting with an antibody, but which are not immunogenic themselves. When haptens are coupled with a protein carrier, they can be made to elicit an immune response by a lymphocyte to produce an antibody. The antibodies thus formed do recognize and react with the hapten in the absence of the protein carrier. Exemplary of haptens are steroids, prostaglandins, thyroxine and various drugs.
Until relatively recently, sensitive and specific methods for measuring the concentration of haptens in serum were not available. In recent years, various immunoassay procedures have been developed. The technique of competitive radioimmunoassay is described in general by the following equation wherein the asterisk represents a radioactive label: ##STR1##
In this procedure, the unlabeled hapten competes with labeled hapten for a limited number of available antibody binding sites, thereby reducing the amount of labeled hapten bound to antibody. The level of radioactivity bound is, therefore, inversely related to the concentration of hapten in the patient sample or standard. After an adequate incubation period, the bound and free fractions are separated and the radioactivity is quantitated.
The amino acid 3,5,3',5'-tetraido-L-thyronine is commonly called thyroxine and is often referred to as T 4 . The designation T 4 is understood to mean the L isomer. It is a hormone having as its principal function a stimulating effect on metabolism.
T 4 is the predominant iodothyronine secreted from the thyroid, and the measurement of serum T 4 concentration has become the test commonly employed as an initial procedure in the diagnosis of states of altered thyroid function, such as hyperthyroidism or hypothyroidism. In addition, it is well known that several conditions other than thyroid disease may cause abnormal serum levels of T 4 . Among these are pregnancy, estrogenic or androgenic steroids, oral contraceptives, hydantoins and salicylates, stress, hyper- and hypo-proteinemia, and conditions (hereditary or acquired) which cause alterations in serum levels of thyroid binding globulin (TBG) the major serum T 4 transport system.
Early T 4 determinations were indirect measurements of the concentration of protein-bound or butanol-extractable iodine in serum. Later, competitive protein binding (CPB) assays were developed. More recently, radioimmunoassay procedures have been developed which use both polyclonal and monoclonal antibodies.
In general, radioimmunoassay procedures in the art measure counts of radioactivity which are related to the affinity of the antibody for the hapten. Two parameters, B 0 and B, related to the counts of labeled hapten, are used in radioimmunoassay procedures. The B 0 value is the number of counts of labeled hapten bound under specific conditions by a given amount of antibody in the absence of unlabeled hapten. The B value is the number of counts of labeled hapten bound under the same conditions in the presence of unlabeled hapten. In a radioimmunoassay, radioactivity counts are conventionally presented as B/B 0 ×100, referred to in the art as assay curve parameters, and are compared by plotting curve parameters against hapten concentration.
In order for antibodies to be suitable for use in a radioimmunoassay for T 4 , the antibodies must have an affinity for T 4 which is neither too high nor too low. If the affinity of the antibody for T 4 is too low, the assay may not reach equilibrium between bound T 4 and unbound T 4 , and any assay design may be invalid. If the affinity of the antibody for T 4 is too high, curve parameters, such as the 100, 90, 50, 10 and 0% ratios of B/B 0 may exhibit excessive deviations from the theoretical straight line plot. A radioimmunoassay for T 4 generally is configured so that the 50% B/B 0 ratio occurs within the accepted "normal" range of serum T 4 concentrations. In the absence of this configuration, determinations of serum T 4 concentrations above and below the normal range may be inaccurate.
Numerous monoclonal antibodies derived from mouse lymphocytes and mouse myeloma cells (mouse-mouse antibodies) have been produced and reported. Representative disclosures are found in the following patents and published applications:
International Application No. PCT/US81/01291, publication No. WO 82/01192 to Trowbridge, and U.S. Pat. Nos. 4,172,124, 4,349,528 and 4,196,265 to Koprowski.
Conventional polyclonal antisera have been used for many years for identifying antigens and haptens. In recent years monoclonal antibodies have been applied to such assays. European Patent Application No. 82302231, publication No. 0064401, to Gillis discloses preparation of antibodies for use in serological detection of the T-cell activator interleukin-2. European Patent Application No. 81303286.9, publication No. 0044722, to Kaplan et al discloses human-human monoclonal antibodies directed to a wide variety of haptens and antigens.
European patent application No. 81105024.4, publication No. 44441, to Molinaro et al. describes mouse-mouse monoclonal antibodies specific to various haptenic drugs, such as gentimicin. Monoclonal antibodies to digoxin were described by Hunter in the J. of Immunology, 129,1165 (1982).
A monoclonal antibody kit for radioimmunoassay of serum T 4 levels is presently marketed by Mallinkrodt, Inc., Immunoassay Systems St. Louis, Mo. under the tradename SPAC® T 4 . Monoclonal antibodies to T 4 are described by Wang et al., in two articles entitled "Monoclonal antibodies to Thyroid Hormones," Monoclonal Antibodies and T-Cell Hybridomas, p. 357, G. Hammerling et al., ed., Elsevier North Holland Biomedical Press, Amsterdam, Netherlands, 1981, and "Monoclonal Antibodies in Clinical Diagnosis," Protides of the Biological Fluids, p. 817, H. Peeters, ed., Pergamon Press, New York, N.Y. 1981. The antibodies described by Wang et al. are hereinafter referred to as Miles antibodies.
SUMMARY OF THE INVENTION
The method of the present invention for the immunoassay of T 4 uses a combination of particular monoclonal antibodies. The monoclonal antibodies are produced by two new and separate hybridoma cell lines, identified as American Type Culture Collection (ATCC) Numbers HB 8499 and HB 8500. Each of the hybridomas was produced by inoculation of mice with T 4 conjugated to a carrier protein and fusion of the resulting lymphocytes with mouse myeloma cells. The use of the combination of monoclonal antibodies to T 4 provides an immunoassay for T 4 with improved affinity and accuracy.
The method for immunoassay of the invention is preferably a solid phase assay, which may be carried out by any immunoassay technique, such as a sandwich assay, an inhibition assay, or a competitive assay.
The two monoclonal antibodies of this invention have different affinities for T 4 and can be used in the combination in any suitable proportion. When combined in suitable proportions, the two monoclonal antibodies of this invention achieve the desired curve parameters. The curve parameters may be chosen such that the 50% B/B 0 ratio falls within the accepted "normal" range for serum T 4 . The desired parameters may be attained with different batches of the monoclonal antibodies merely by variation of the proportion. By use of the antibody combination, the assay may be configured to operate in the range of maximum accuracy of radioimmunoassay design and thereby provide high sensitivity and accuracy over the range of T 4 concentrations encountered in a serum sample.
In the following detailed description of the invention, the following abbreviations are used:
ATCC--American Type Culture Collection
CGG--chicken gamma globulin
cpm--counts per minute
FBS--fetal bovine serum
FCA--Freund's complete adjuvant
FIA--Freund's incomplete adjuvant
HAT--hypoxanthine-aminopterin-thymidine
HT--hypoxanthine-thymidine
ID--intradermal
Ig--immunoglobulin
IP--intraperitoneal
IV--intravenous
LPRIA--liquid phase radioimmunoassay
MSID--multiple sites intradermal
PBS--phosphate buffered saline
PEG--polyethylene glycol
RIA--radioimmunoassay
RPMI--Roswell Park Memorial Institute medium
RT--room temperature
SC--subcutaneous
SPRIA--solid phase radioimmunoassay
TBG--thyroxine binding globulin
T 4 --L-thyroxine
T 4 *--L-thyroxine 125 I
DETAILED DESCRIPTION OF THE INVENTION
While this invention is satisfied by embodiments in many different forms, there will herein be described in detail a preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and is not intended to limit the invention to the embodiment described. The scope of the invention will be measured by the appended claims and their equivalents.
T 4 is a hapten, and as such it can interact with combining sites on a specific antibody. T 4 is non-immunogenic by itself, and thus does not cause the formation of antibodies when introduced into a host animal. However when T 4 is coupled to a carrier protein, it does elicit an immune response to produce antibodies capable of binding T 4 . In the present invention, T 4 is chemically conjugated by conventional means to a carrier protein of molecular weight from about 5,000 to about 1,000,000 daltons, preferably from about 30,000 to about 200,000 daltons. Particularly useful carrier proteins to provide the conjugate are albumins or globulins, as for example CGG, although other classes of proteins, such as enzymes, may be used. Methods to attach such carrier materials to haptens are well known in the art and have been described by Parker in Radioimmunoassay of Biologically Active Compounds, Prentice-Hall, 1976.
For the production of monoclonal antibodies specific for T 4 in accordance with this invention, immunization is initiated by inoculation of a host animal with the conjugate. Although the preferred embodiment herein described utilizes a mouse as the host animal, it is understood that the invention is not limited to mouse-derived monoclonal antibodies and other species, as, for example, rat or human, may be used.
Particularly advantageous strains of mice for this invention are BALB/c mice and C 3 H mice. The mice may be from about 3 weeks to 30 weeks old at the time of the first inoculation, preferably 3 to 6 weeks old for the BALB/c mice and 25-30 weeks old for the C 3 H mice. Multiple inoculations are made over a period of from about 1 to about 300 days, preferably from about 1 to about 200 days. Inoculations may be made by the IP, IV or ID routes at one or more body sites with a dose of from about 5 to about 50 ug of conjugate per injection. The conjugate may be injected alone or may be mixed with a substance which increases the immunogenicity of the conjugate. Exemplary of such substances are, for example, a suspension of B. pertussis, or FCA or FIA. For injections made intravenously, the conjugate is dissolved in a physiologically acceptable vehicle, such as, for example, saline or PBS.
At the conclusion of the immunization period, the sensitized lymphocytes are harvested from various sites such as the lymph nodes or, preferably the spleen. The lymphocytes are suspended in a medium such as serum free RPMI 1640 medium (Seromed, Muchen, Federal Republic of Germany) at a concentration of about 5×10 7 cells/ml.
The isolated lymphocytes are fused with mouse myeloma cells whereby the ability of the lymphocytes to produce antibodies is joined with the ability of the myeloma cells to grow indefinitely in tissue culture. In the selection of the myeloma cells to be used for the fusion, it is preferred that the myeloma cells and lymphocytes be derived from the same species to enhance the likelihood that the genetic and biochemical properties of the parent cells will be compatible and thus produce viable hybridomas. For the present invention, it is advantageous to select a myeloma line which does not produce antibodies itself, i.e., a non-producing cell line, so that the resulting hybridoma will only produce antibodies specific for T 4 . In addition, it is advantageous to select a myeloma cell line in which a deficiency of an enzyme essential for nucleotide synthesis has been introduced by pretreatment with a cytotoxic agent, to thereby facilitate subsequent separation of hybridoma cells from unfused lymphocytes and myeloma cells. Preferred enzyme deficient myeloma cell lines are those which cannot grow in the culture medium conventionally known as HAT medium as described in Science 145,709 (1964). A particularly preferable myeloma cell line for the present invention is the non-antibody-producing P3X63-Ag8.653 (ATCC CRL 1580), described by Kearney, et al., J. of Immunology, 123, 1548 (1979). It is understood, however, that other tumor cell lines may be used, as, for example, P3/NS1/1-Ag4-1 (ATCC TIB 18). These and other mouse myeloma cell lines have been characterized and are on deposit with the ATCC.
In preparation for fusion, the myeloma cells are selected at mid-log growth phase. The cells are counted, isolated from their stock medium by centrifugation, and the pellet is suspended in serum free RPMI at a concentration of about 5×10 6 cells/ml.
Fusion usually occurs at a rate of about 1 hybridoma per 1×10 5 parent lymphocyte cells used. In order to get sufficient hybridomas for subsequent processing, it is advantageous to use from about 1×10 6 to 1×10 10 preferbly about 1×10 7 to about 1×10 8 lymphocytes for the fusion. Any ratio of lymphocytes to myeloma cells may be used, but a higher percentage of fusion events takes place if a ratio of lymphocytes to myeloma cells of from about 5:1 to about 20:1, preferably about 8:1 to 12:1 is used. Thus, preferably, about 1×10 7 myeloma cells are used for fusion with about 1×10 8 lymphocytes. A conventional fusing agent is used, as, for example, sendai virus or, preferably, PEG. The PEG may be of any molecular weight from about 1000 to about 6000, preferably about 3500 to 4500. It is used as a solution of from about 25% to about 50% in RPMI medium, preferably a concentration of about 35% to about 40% is used.
Fusion is carried out by mixing the fusion agent with the desired cell quantities and ratio. The quantity of fusing agent solution used is about 20-40% of the total volume of the fusion mixture, preferably about 25%. A particularly preferable fusion mixture is about 0.5 ml of 37.5% PEG 6000 in RPMI added to a cell pellet containing 5×10 7 lymphocytes and 5×10 6 myelomas. The mixture is maintained at room temperature for from about 5 to about 20, preferably about 10 minutes.
The hybridomas are separated from unfused myeloma and lymphocyte cells by addition of the fusion mixture to a medium which will support growth of the hybridomas but not the unfused cells. Conventional HAT concentration as defined in Science 145, 709 (1964) in the presence of RPMI and FBS may be used for this purpose. Preferably a mixture of 4 ml RPMI and 1 ml FBS containing the defined HAT concentration is used. Aliquots of the mixture are added to a multiplicity of wells of a microtiter plate. After an appropriate incubation period, usually about 2 weeks, some of the wells will show growth by macroscopic observation. However, since a mixed lymphocyte population was presented to the myeloma cells for fusion, the resulting hybridomas will secrete antibodies of differing specificities to T 4 .
Conventional assay means, as, for example, SPRIA and LPRIA, are used to determine these specificities. In a typical procedure, polyvinyl chloride microtiter plates are coated with anti-mouse Ig and incubated with culture supernatants from wells showing hybridoma growth. Incubation with known amounts of T 4 * is also carried out, and the amount of bound T 4 * is determined using a gamma counter. The amount of radioactivity is proportional to the amount of antibody specific for T 4 in the supernatant.
The sensitivity, affinity and cross-reactivity of the monoclonal antibodies to T 4 may be determined using conventional LPRIA. Further specificity determination may be made using a competitive LPRIA using triiodothyronine (T 3 ). The hybridoma cells in those wells thus determined to contain antibodies of sufficient specificity and affinity for T 4 are cloned by conventional limiting dilution procedures to ensure monoclonality. This procedure is repeated at least 3 times to confirm stability of the hybridoma cell lines. From the final limiting dilution clone plate indicating stability of the hybridoma, one hybridoma clone is isolated from each individual hybridoma cell line and expanded to about 2×10 8 cells per ml. Seed stocks of this hybridoma are frozen and stored in ampoules, preferably at less than -100° C., under nitrogen, at about 1×10 7 cells per ml. Stability is evaluated after freezing by further cloning at limiting dilution.
For production of monoclonal antibodies from the selected hybridoma, growth may be carried out in vitro according to known tissue culture techniques, such as is described by Cotton et al. in European Journal of Immunology, 3, 136 (1973), or preferably the hybridoma may be grown in vivo as tumors in a histocompatible animal. In this preferred embodiment, a seed ampoule is thawed, and the hybridoma cells are expanded and injected into, for example, syngeneic mice at 1×10 6 cells/per animal. In a particularly preferred embodiment, the mice are primed with a substance as, for example, pristane (2,6,10,14-tetramethyl pentadecane) one week before injection to increase the formation of ascites fluid. After a time period of from about one to three weeks, tumor bearing animals are tapped for ascites fluid. Further testing of the monoclonal antibodies thus prepared for specificity to T 4 is carried out by RIA as described above.
The hybridomas of the present invention, obtained by immunization of BALB/c mice and C 3 H mice are designated ATCC HB 8499 and ATCC HB 8500, respectively and have been deposited with the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Md. 20852. The monoclonal antibodies elaborated by the hybridoma designated ATCC HB 8499 and by the hybridoma designated ATCC HB 8500 are homogeneous and react with concentrations of T 4 as low as 1.8 ng/ml. They have high specificity for T 4 and show cross reactivity to T 3 which may be as low as 0.12%. The monoclonal antibody from the hybridoma designated ATCC HB 8500 has greater affinity for T 4 than any known T 4 specific monoclonal antibody. This affinity may be as high as 2.6×10 9 liters per mole. The monoclonal antibodies of the invention may be used in a method for solid phase immunoassay of T 4 . The assay may be performed by any immunoassay technique, such as inhibition assay, sandwich assay, or competitive assay. Any suitable solid phase may be used, preferably a polymeric solid phase, such as polypropylene, polyvinyl chloride, polystyrene, polyethylene, latex or polyacrylamide.
The quantity of the monoclonal antibody from the hybridoma designated ATCC HB 8499 which may be used in the assay may be from 0.0025% to 0.05%, preferably 0.013% to 0.025%. The quantity of the monoclonal antibody from the hybridoma designated ATCC HB 8500 which may be used in the assay may be from 0.005% to 0.025%, preferably from 0.0067% to 0.0083%.
In the competitive assay technique of the invention the solid phase having suitable quantities of the two monoclonal antibodies attached may be reacted with a solution containing a predetermined number of counts of 125 I labeled T 4 and a serum sample containing an unknown amount of T 4 . A binding reaction between the monoclonal antibodies and the T 4 and the labeled T 4 may be induced, preferably by incubating the assay medium at a suitable temperature for a suitable time. The solid phase may be separated from the liquid phase of the assay medium and the number of counts of radioactivity from the solid phase determined. The procedure may be repeated with a plurality of solutions containing predetermined and different amounts of T 4 , and with a solution devoid of T 4 . The unknown amount of T 4 in the serum sample may be determined by comparing the number of counts of radioactivity measured upon assay of the serum sample with the number of counts measured upon assay of the solutions containing predetermined amounts of T 4 .
The present invention will be illustrated by the following examples, but is not intended to be limited thereby.
EXAMPLE 1
Preparation of T 4 -CGG Conjugate
T 4 (116.5 mg, 150 uM) was placed in 5 ml of 0.1 m phosphate buffer, pH 11.9. Eighty five ul of toluene diisocyanate (TDIC) was added and the mixture was stirred vigorously at 0° C. for 30 minutes, centrifuged at 0° C., and the supernatant allowed to incubate for 1 hour at 0° C. and added to a solution of 70 mg of CGG, MW 170,000 in 5 ml of 0.1M phosphate buffer, pH 11.9. After 1 hour at 37° C. the mixture became cloudy. The mixture was dialyzed against 0.1M (NH 4 ) 2 CO 3 solution overnight to destroy any excess TDIC, and then dialyzed against 0.1M phosphate buffer, pH 11.9. The solution thus prepared was used for inoculation.
Immunization
BALB/C mice which were 5 weeks old on day 1 were immunized according to the following protocol:
______________________________________ QUANTITY (ug)DAY INJECTANT of T.sub.4 -CGG ROUTE______________________________________ 1 T4-CGG 1:1 CFA* 50 IP 33 T4-CGG 1:1 FIA 10 IP 49 " 10 IP110 " 10 IP140 T4-CGG 3:1 FIA 10 IP168 T4-CGG 1:1 FIA 10 IP207 T4-CGG in PBS 10 IV208 " 10 IV209 " 10 IV210 Spleens harvested for fusion______________________________________ *A mixture of equal parts by volume.
C 3 H mice 27 weeks old on day 1 were immunized by MSID injection with 10 ug of T4-CGG and 50 ul of B. pertussis suspension on days 1, 14, 33, 49, 63, 77 and 100. On day 245, a solution of 10 ug of T4-CGG in saline was injected IP. On day 248, the spleens were harvested for fusion.
Isolation of Spleen Cells
The mice from each group were sacrificed by cervical dislocation and the spleens were removed into a 60 mm. petri dish containing 5 ml of sterile RPMI containing 5% FBS. After rinsing, the spleens were transferred to a second dish and perfused. The spleen sacks were teased apart and the cells were pipetted into a 15 ml centrifuge tube. Centrifugation was carried out at 500 rpm for 5 min. The pellet was suspended in serum free RPMI to yield 5×10 7 lymphocytes/ml.
Preparation of P3X68-Ag8.653 Myeloma Cells
Myeloma cells at the midpoint of the log growth phase were counted, centrifuged at 500 rpm for 5 min. and suspended in serum free RPMI at room temperature to give a suspension of 5×10 6 cells/ml.
Fusion
One ml each of spleen and myeloma cells was mixed in a 17×100 mm round bottom tube and topped with about 10 ml of serum free RPMI at RT. The supernatant was decanted, the tube was tapped to break up the pellet, and 0.5 ml of 37.5% PEG in RPMI previously incubated under 7% CO 2 was added. The tube was tapped to mix and incubated at RT for 10 min., during which a 3 minute spin at 500 rpm was carried out.
Serum free RPMI (4 ml) was added to quench the reaction and the tube was tapped to mix and poured into a mixture of 5 ml RPMI-20% FBS, 1 ml FBS and 0.1 ml of modified HAT. Incubation overnight at 37° C. was then carried out.
Growth and Selection
On day 1 after fustion, 23.5 ml of RPMI-20% FBS-HAT medium were added so that the concentration of spleen cells was 2×10 7 /14 ml. Using a sterile 10 ml glass pipet, 2 drops of the mixture were added to each well of a 96-well microtiter plate. On day 9, 1 drop of RPMI-20% FBS-HT medium was added to each well. When growth appeared macroscopically (about day 14), the supernatants were taken for testing and replaced with RPMI-20% FBS-HT medium.
Screening of Supernatants for Antibodies
The supernatant from wells showing growth were tested by solid phase RIA for antibodies to T 4 . Ninety six well polyvinyl chloride microtiter plates (Dynatech Labs) were charged with 100 ul of antimouse IgG diluted in pH 9.6 carbonate buffer, leaving several wells for positive and negative controls. The negative control for this assay was P3X63-Ag8.653 supernatant diluted 1:5 with PBS-0.05% Tween 20 (polyoxyethylenesorbitan monolaurate). Positive control was a 1:300 dilution of Miles antibodies, diluted in PBS-0.05% Tween 20 or a 1:5 dilution of an established T 4 hybridoma that is available either as fresh or frozen supernatant. The microtiter plate was covered with Parafilm and incubated overnight at 4° C. The plate was emptied and the wells were washed 3 times with PBS-0.05% Tween 20. Samples and appropriate negative and positive controls were diluted 1:5 with PBS-0.05% Tween 20 and 50 ul dispensed per well to the washed plate. The plate was covered with parafilm, incubated 1 hour at 37° C., and washed 3 times with PBS-0.05% Tween 20. T 4 * was diluted with PBS-0.05% Tween 20 to obtain approximately 70,000 cpm per 50 ul, and 50 ul was dispensed to each well and to duplicate 12×75 mm polypropylene tubes labeled "total cpm." The plates were covered with Parafilm, incubated 1 hour at 37° C., aspirated to remove the label, and the wells were washed 3 times with PBS-0.05% Tween 20. After drying the plates on a paper towel, the radioactivity was counted in the gamma counter for 30 seconds per sample. The radioactivity in the "total cpm" tubes was also counted.
Stability Test of Selected Clones
The cultures of those hybridomas shown by SPRIA and LPRIA to produce antibodies specific to T 4 were counted by staining with Trypan Blue and diluted to about 10 viable cells/ml. About 100 ul of cell suspension were added per well to a 96 well plate (calculated to provide about 1 cell per well), and the plate was incubated under 7% CO 2 . About day 14, visible hybridomas were tested for antibody production. The screening and stability test steps were repeated several times with the T 4 specific antibody-producing hybridomas showing the highest stability and antibody specificity. A final selection of the best hybridoma from each mouse line was made and the hybridomas designated as follows:
from BALB/c mice'ATCC HB 8499
from C 3 H mice--ATCC HB 8500 | Monoclonal antibodies specific for thyroxine (T 4 ) are produced by two new and separate hybridoma cell lines. Combinations of the monoclonal antibodies from the two cell lines are used in an immunoassay for T 4 of high accuracy over the range of T 4 concentrations encountered in serum samples. | 8 |
This is a Continuation-In-Part Application of U.S. Ser. No. 08/013,527, filed Feb. 4, 1993, now abandoned, which is a Continuation-In-Part application of U.S. Ser. No. 07/831,724, filed Feb. 5, 1992, now U.S. Pat. No. 5,382,654, Ser. No. 07/842,017 filed Feb. 25, 1992, now abandoned; and U.S. application Ser. No. 08/183,270, filed Jan. 19, 1994, now abandoned, which is a Continuation of U.S. application Ser. No. 07/584,317, filed Sep. 14, 1990, now abandoned. The entirety of each of these applications is incorporated herein by reference hereto.
FIELD OF THE INVENTION
The present invention relates to novel ligands for forming radionuclide complexes, new complexes incorporating such ligands, processes for preparing such complexes, imaging agents incorporating such complexes, and methods of imaging using such imaging agents.
BACKGROUND OF THE INVENTION
Scintigraphic imaging and similar radiographic techniques for visualizing tissues in vivo are finding ever-increasing application in biological and medical research and in diagnostic and therapeutic procedures. Generally, scintigraphic procedures involve the preparation of radioactive agents which upon introduction to a biological subject, becomes localized in the specific organ, tissue or skeletal structure of choice. When so localized, traces, plots or scintiphotos depicting the in vivo distribution of radiographic material can be made by various radiation detectors, e.g., traversing scanners and scintillation cameras. The distribution and corresponding relative intensity of the detected radioactive material not only indicates the space occupied by the targeted tissue, but also indicates a presence of receptors, antigens, aberrations, pathological conditions, and the like.
In general, depending on the type of radionuclide and the target organ or tissue of interest, the compositions comprise a radionuclide, a carrier agent designed to target the specific organ or tissue site, various auxiliary agents which affix the radionuclide to the carrier, water or other delivery vehicles suitable for injection into, or aspiration by, the patient, such as physiological buffers, salts, and the like. The carrier agent attaches or complexes the radionuclide to the carrier agent, which results in localizing the radionuclide being deposited in the location where the carrier agent concentrates in the biological subject.
Triamidethiolate and diamidedithiolate ligands have been used successfully for radiolabeling macromolecules. In general, amide-thiolate systems require harsh (75° C.-100° C.) radiolabeling conditions for preparing Tc and Re complexes. Under these conditions, the stability and biological properties of the small and medium bioactive peptides are often degraded.
In order to avoid harsh labeling conditions, pre-formed complexes have been coupled to the protein with some success. See Fritzberg et al., U.S. Pat. Nos. 4,965,392 and 5,037,630 incorporated herein by reference. In the "pre-formed approach," the ligand is complexed with the radionuclide and then conjugated to the bioactive peptide. A major disadvantage of the pre-formed approach is that the end user must perform both the radiolabeling step and the coupling step (attaching the complex to the bioactive peptide). The final product must be purified prior to administration. In the case of small and medium sized peptides, the metal-complex may potentially react with "active sites" of the peptide. Thus, site specific attachment of a ligand to a bioactive molecule is only possible with post-formed complexes.
In the conventional "post-formed approach," the ligand is first conjugated to the peptide and the resulting conjugate is labeled with the radioisotope under complex forming conditions. In the present invention, the post-formed approach has the additional advantage of allowing preparation of the conjugated bioactive peptide in kit form. The end users would perform only the radiolabeling step.
It has been found that the presence of free thiol (instead of protected thiol) and/or replacement of an amide with an amine causes labeling of N 2 S 2 and N 3 S ligands to proceed under milder conditions, but at the expense of some complex stability. See Rao et al., "Tc-Complexation of N 2 S 2 Monoaminemonoamides," Int. J. Radiat. Part B, (1991) (in press). In addition, Misra et al., "Synthesis of a Novel Diaminodithiol Ligand for Labeling Proteins and Small Molecules with Technetium-99 m," Tetrahedron Letters, Vol. 30, No. 15, pp. 1885-88 (1989) and Baidoo et al., "Synthesis of a Diaminedithiol Bifunctional Chelating Agent for Incorporation of Technetium-99 m into Biomolecules," Bioconjugate Chemistry, Vol. 1, pp. 132-37 (1990), report that diaminedithiol (DADT) ligands label with 99m Tc at ambient temperatures.
Gustavson et al., "Synthesis of a New Class of Tc Chelating Agents: N 2 S 2 Monoaminemonoamide (MAMA) Ligands," Tetrahedron Letters, Vol. 32, No. 40, pp. 5485-88 (1991), compares the radiolabeling efficiency of a N 2 S 2 -diamidedithiol (DADS) ligand with a N 2 S 2 -monoamine amide (MAMA) ligand. It was found that substitution of the amide nitrogen in the DADS ligand with an amine nitrogen in the MAMA ligand produced a threefold increase in radiochemical yield when labeling with 99m Tc at 37° C. for 30 minutes. ##STR1## Notwithstanding the improved metal complex formation kinetics reported with amine-containing N 2 S 2 and N 3 S ligands, Tc and Re amide-thiolate complexes assure maximum in vivo stability and inhibit metal oxidation to the pertechnetate or perrhenate oxidation state.
From the foregoing, what is needed in the art are novel ligands for forming radionuclide complexes, complexes incorporating such ligands, processes for preparing such complexes, imaging agents incorporating such complexes, methods of imaging using such imaging agents, and, in particular, an amide-thiolate ligand with improved complex formation kinetics which can be labeled under mild conditions and which has excellent in vivo complex stability.
SUMMARY OF THE INVENTION
The present invention is directed to novel aminothiol ligands that are suitable for complexing with a radionuclide and which are useful as general imaging agents for diagnostic purposes and novel amide-thiolate ligands having improved complex formation kinetics. The present invention also includes radiolabeled peptide compounds utilizing the disclosed ligands, methods of preparing these compounds, pharmaceutical compositions comprising these compounds and the use of these compounds in kits for therapeutic and diagnostic applications.
The N 3 S amide-thiolate ligands according to the present invention contain an amine within the N 3 S core, to enhance initial complex formation kinetics, which converts to a thermodynamically stable amide during complex formation. Metal chelate complex formation occurs under mild conditions which do not adversely affect the targeting ability or biological activity of the carrier molecule. For most purposes, a complexing temperature in the range from about 25° C. to about 50° C. and a pH in the range from about 3-8 are sufficiently mild for small and medium peptides.
The amide-thiolate and aminothiol ligands within the scope of the present invention can be coupled as conjugates with biologically active molecules or biomolecules that are known to concentrate in the organ or tissues to be examined. These biomolecules include, for example, growth factors and synthetic analogs such as somatostatin, hormones such as insulin, prostaglandins, steroid hormones, amino sugars, peptides, proteins, lipids, conjugates with albumins, such as human serum albumin, antibodies, monoclonal antibodies specific to tumor associated antigens, or antimycin, and the like. The diagnostic media formed therefrom may be used in diagnostic and therapeutic applications.
In the present invention, the amide-thiolate and/or amino thiol ligand is coupled to a biomolecule according to standard procedures known in the art. In the case of small to medium peptides, the active sites of the biomolecules are protected so that the ligand is specifically attached to functional groups that are not involved in binding the biomolecules to the target receptor.
The ligands and biomolecule conjugates described above are useful in diagnostic and radiotherapy applications. The compounds of the present invention may be labeled with any suitable radionuclide favorable for these purposes. Such suitable radionuclides for radiotherapy include but are not limited to 186 Re, 188 Re, 67 Cu, 90 Y, and 60 Co. For diagnostic purposes the most suitable radionuclides include, but are not limited to, the transition metals as exemplified by 99m Tc, 111 In, and 62 Cu.
It is therefore an object of the present invention to provide amide-thiolate ligands having improved complex formation kinetics which can be labeled under mild conditions and which have excellent complex stability and aminothiol ligands suitable for use as a radionuclide when complexed with a suitable metal.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates, in one significant aspect, to novel aminothiol ligands that are suitable for complexing with a radionuclide and which are useful as general imaging agents for diagnostic purposes. In particular the present invention relates to novel ligands having the general formula: ##STR2## wherein R 1 is selected from the group consisting of hydrogen, alkyl, hydroxyl, alkoxyl, hydroxyalkyl, alkoxyalkyl, alkoxycarbonyl, or carbamoyl, wherein the carbon containing portion of such group contains 1 to 10 carbon atoms; R 2 is a suitable sulfur protecting group selected from the group consisting of acetyl, benzoyl, methoxyacetyl, 1-3-dioxacyclohexyl, 1,3-dioxacyclopentyl, alkoxycarbonyl, carbamoyl, alkoxyalkyl, dialkoxyalkyl, tetrahydropyranyl, tetrahydrofuranyl, p-methoxybenzyl, benzhydryl, trityl, and the like; L is selected from the group consisting of ##STR3## wherein k, l, m and n are 0 to 10, preferably 1 to 6; E is --O--, --S--, or --NR 3 , wherein R 3 and R 4 are defined in the same manner as R 1 above, and wherein X is a suitable coupling moiety selected from the group consisting of formyl, carboxyl, hydroxyl, amino, t-butoxycarbonylamino, chloro-carbonyl, N-alkoxycarbamoyl, succinimidoloxycarbonyl, imidate, isocyanate, isothiocyanate, tetrafluorophenoxy, and the like; A is selected from the group consisting of ##STR4## wherein R 5 to R 7 are defined in the same manner as R 1 above, and wherein Y is defined in the same manner as L above; and B is selected from the group consisting of ##STR5## wherein R 8 and R 9 are defined in the same manner as R 1 above, and wherein Z is defined in the same manner as L above.
In a preferred embodiment, ligands according to the present invention have the general Formula (I) above, wherein A is ##STR6## wherein R 5 and Y are hydrogens; B is ##STR7## wherein R 8 is hydrogen and Z is ##STR8## wherein R 4 is hydrogen, E is an --NH-- group, m is 2, n is 3, and X is carboxyl; R 2 is a benzoyl or a tetrahydropyranyl group; and L is hydrogen.
In another preferred embodiment, ligands according to the present invention have the general Formula (I) wherein A is ##STR9## wherein R 5 and Y are hydrogens; B is ##STR10## wherein R 8 is hydrogen and Z is --(CH 2 ) k --X wherein k is 2 or 4, and X is one of an amino, a carboxyl or a hydroxyl; R 2 is a benzoyl or a tetrahydropyranyl group; and L is hydrogen.
The novel ligands described above may be incorporated into radionuclide complexes used as radiographic imaging agents. Further, these ligands or complexes can be covalently or non-covalently attached to biologically active carrier molecules, such as, antibodies, enzymes, peptides peptidomimetics, hormones, and the like. The complexes of the present invention are prepared by reacting one of the aforementioned ligands with a radionuclide containing solution under radionuclide complex forming reaction conditions. In particular, if a technetium agent is desired, the reaction is carried out with a pertechnetate solution under technetium 99 m complex forming reaction conditions. The solvent may then be removed by any appropriate means, such as evaporation. The complexes are then prepared for administration to the patient by dissolution or suspension in a pharmaceutically acceptable vehicle.
The ligands of the present invention may be prepared from commercially available starting materials such as 2-(2-aminoethyl) pyridine, 2-aminomethyl pyridine, lysine, glutamic acid, aminoadipic acid, mercaptoacetic acid, etc. by standard synthetic methods as described in the Examples.
Radionuclide complexes of the above-described ligand may have the general formula: ##STR11## wherein M represents an appropriate radionuclide, such as technetium or rhenium and wherein R 1 , L, A and B are as defined above in Formula (I).
In a preferred embodiment, a technetium radionuclide complex having the general Formula (II) may be formed from a pertechnetate solution and a ligand having the general Formula (I) above, wherein R 1 and L are hydrogens; A is ##STR12## wherein R 5 and Y are hydrogens; and B is ##STR13## wherein R 8 is hydrogen and Z is ##STR14## wherein R.sup. 4 is hydrogen, E is an --NH-- group, m is 2, n is 3, and X is carboxyl.
In another preferred embodiment, a technetium complex having the general Formula (II) may be formed from a pertechnetate solution and a ligand having the general Formula (I) above, wherein R 1 and L are hydrogens; A is ##STR15## wherein R 5 and Y are hydrogens; and B is ##STR16## wherein R 8 is hydrogen and Z is --(CH 2 ) k --X wherein k is 2 or 4, and X is one of an amino, a carboxyl or a hydroxyl.
The radionuclide containing solution may be obtained from radionuclide generators in a known manner. For example, when forming a technetium complex, the pertechnetate solution may be obtained from a technetium generator in a known manner. The radionuclide complex forming reaction is then carried out under appropriate reaction conditions. For example, the technetium 99 m complex forming reaction is carried out under technetium complex forming temperatures, e.g. 20° C. to 100° C. for 10 minutes to several hours. The pertechnetate is used in technetium complex forming amounts, e.g. about 10 -6 to 10 -2 molar amounts.
The present invention also relates to imaging agents containing a radionuclide complex as described above, in an amount sufficient for imaging, together with a pharmaceutically acceptable radiological vehicle. The radiological vehicle should be suitable for injection or aspiration, such as human serum albumin; aqueous buffer solutions, e.g tris(hydromethyl) aminomethane (and its salts), phosphate, citrate, bicarbonate, etc; sterile water; physiological saline; and balanced ionic solutions containing chloride and or dicarbonate salts or normal blood plasma cations such as Ca +2 , Na + , K + , and Mg +2 .
The concentration of the imaging agent according to the present invention in the radiological vehicle should be sufficient to provide satisfactory imaging, for example, when using an aqueous solution, the dosage is about 1.0 to 50 millicuries. The imaging agent should be administered so as to remain in the patient for about 1 to 3 hours, although both longer and shorter time periods are acceptable. Therefore, convenient ampules containing 1 to 10 mL of aqueous solution may be prepared.
Imaging may be carried out in the normal manner, for example by injecting a sufficient amount of the imaging composition to provide adequate imaging and then scanning with a suitable machine, such as a gamma camera.
The present invention relates, in another significant aspect, to novel aminothiol ligands that are suitable for complexing with a radionuclide, and are useful as general imaging agents for diagnostic purposes. In particular, the present invention relates to novel ligands having the general formula: ##STR17## wherein R 1 and R 2 may be the same or different and are selected from the group consisting of hydrogen, alkyl, aryl, hydroxyl, alkoxyl, mono- or poly- hydroxyalkyl, mono- or poly- alkoxyalkyl, acyl, alkoxycarbonyl, or carbamoyl; A is selected from the group consisting of ##STR18## wherein n is 1 to 3, wherein R 3 , R 4 and R 5 are defined in the same manner as R 1 and R 2 above, and wherein Y is ##STR19## wherein m is 1 to 3, wherein Z is selected from the Group consisting of ##STR20## wherein R 6 and R 7 are defined in the same manner as R 1 and R 2 above, and wherein J is hydrogen or another suitable protecting group such as ethylaminocarbonyl; and B is selected from the group consisting of ##STR21## wherein p is 1 to 3, wherein 1 is 0 or 1, wherein R 8 and R 9 are defined in the same manner as R 1 and R 2 above, and wherein Y is as defined above.
In a preferred embodiment, ligands according to the present invention have the general formula (III) above, wherein R 1 is hydrogen; R 2 is selected from the group consisting of butoxycarbonyl, acetyl, ethyl, or hydrogen; A is --(CH 2 ) n -- wherein n=2; and B is ##STR22## wherein 1=0, R 8 is hydrogen and Y is ##STR23## wherein m=1, Z is --H, and J is a suitable protecting group.
The present invention also relates to novel ligands having the general formula: ##STR24## wherein R 10 is selected from the group consisting of hydrogen, alkyl, aryl, hydroxyl, alkoxyl, mono- or poly- hydroxyalkyl, mono- or poly- alkoxyalkyl, acyl, alkoxycarbonyl, or carbamoyl; R 11 is a suitable sulfur protecting group selected from the group defined in the same manner as R 10 above; D is selected from the group consisting of ##STR25## wherein i is 1 to 3, wherein R 12 , R 13 and R 14 are defined in the same manner as R 10 above, and wherein X is ##STR26## wherein g is 1 to 3, wherein Q is selected from the group consisting of ##STR27## wherein R 15 and R 16 are defined in the same manner as R 10 above, and wherein L is hydrogen or another suitable protecting group such as ethylaminocarbonyl; and E is selected from the group consisting of ##STR28## wherein h is 1 to 3, wherein R 17 , R 18 and R 19 are defined in the same manner as R 10 above.
In another preferred embodiment, ligands according to the present invention have the general formula (IV) above, wherein
R 10 is hydrogen; R 11 is ##STR29## D is --(CH 2 ) i -- wherein i=1; and E is ##STR30##
The novel ligands described above, may be incorporated into radionuclide complexes used as radiographic imaging agents. The complexes of the present invention are prepared by reacting one of the aforementioned ligands with a radionuclide containing solution under radionuclide complex forming reaction conditions. In particular, if a technetium agent is desired, the reaction is carried out with a pertechnetate solution under technetium 99 m complex forming reaction conditions. The solvent may then be removed by any appropriate means, such as evaporation. The complexes are then prepared for administration to the patient by dissolution or suspension in a pharmaceutically acceptable vehicle.
The ligands of the present invention may be prepared from commercially available starting materials such as 2-(2-aminoethyl)pyridine, 2-aminomethyl pyridine, homocysteinethiolactone, etc. by standard synthetic methods as described in the Examples.
Radionuclide complexes formed from the above-described ligands may have the general formula: ##STR31## wherein M is an appropriate radionuclide such as technetium or rhenium, and R 1 and R 2 are as defined above in formula (III). In a preferred embodiment a technetium radionuclide complex having the general formula (V) may be formed from a pertechnetate solution and a ligand having the general formula (III) above, wherein R 1 is hydrogen; R 2 is butoxycarbonyl, acetyl, ethyl or hydrogen; A is --(CH 2 ) n -- wherein n=2; and B is ##STR32## wherein 1=0, R 8 is hydrogen and Y is ##STR33## wherein m=1, Z is --H, and J is a suitable protecting Group.
Also, radionuclide complexes according to the present invention may have the general formula: ##STR34## wherein M represents an appropriate radionuclide, such as technetium or rhenium and wherein R 10 is as defined above in formula (IV). In a preferred embodiment, a technetium radionuclide complex having the general formula (VI) may be formed from a pertechnetate solution and a ligand having the general formula (IV) above, wherein R 10 is hydrogen; R 11 is ##STR35## D is --(CH 2 ) i -- wherein i=1; and E is ##STR36##
The radionuclide containing solution may be obtained from radionuclide generators in a known manner. For example, when forming a technetium complex, the pertechnetate solution may be obtained from a technetium generator in a known manner. The radionuclide complex forming reaction is then carried out under appropriate reaction conditions. For example, the technetium 99 m complex forming reaction is carried out under technetium complex forming temperatures, e.g. 20° C. to 100° C. for 10 minutes to several hours. A large excess of the appropriate ligands over the radionuclide complex forming amounts is preferably used. For example, when forming a technetium complex, at least a ten fold excess of the ligands over the pertechnetate solution is used. The pertechnetate is used in technetium complex forming amounts, e.g. about 10 6 to 10 12 molar amounts.
It is believed that certain radionuclide complexes of the present invention incorporating the ligands of the present invention have particular functional use as brain imaging agents. In particular, it is believed that these agents will act as opium alkaloid (e.g. morphine) mimics which may be selectively localized in the brain receptors, and may therefore exhibit optimal properties to function as diagnostic agents for the detection of brain disorders such as Alzheimer's disease, Parkinson's disease, narcotic addiction, etc.
A preferred complex for use in a brain imaging agent according to the present invention has the following formula: ##STR37## wherein R 1 is as defined above in formula (III), and wherein Z is a primary, secondary or tertiary amino functionality. This complex may be formed by reaction of a pertechnetate solution with a ligand according to the present invention having the general formula (III) above, wherein R 1 is, in particular, hydrogen, hydroxyl, or methoxyl; R 2 is CH 3 ; A is ##STR38## wherein R 4 and R 5 are hydrogen and Y is ##STR39## wherein m=1, Z is ##STR40## wherein R.sup. 6 is hydrogen or CH 3 and R 7 is hydrogen or CH 3 , and J is a suitable protecting group; and B is ##STR41## wherein 1=1, R 8 is hydrogen and Y is --H.
A further preferred complex for use in a brain agent according to the present invention has the following formula: ##STR42## wherein R 10 is as defined above in formula (IV), and wherein Q is a primary, secondary or tertiary amino functionality. This complex may be formed by reaction of a pertechnetate solution with a ligand having the general formula (IV) above, wherein R 10 is, in particular, hydrogen, hydroxyl, or methoxyl; R 11 is hydrogen or another suitable protecting group; D is ##STR43## wherein R 13 and R 14 are hydrogen and X is ##STR44## wherein g=1, Q is ##STR45## wherein R 15 is hydrogen or CH 3 and R 16 is hydrogen or CH 3 , and L is a suitable protecting group; and E is ##STR46## wherein R 18 and R 19 are hydrogen.
The present invention also relates to imaging agents containing a radionuclide complex as described above, in an amount sufficient for imaging, together with a pharmaceutically acceptable radiological vehicle. The radiological vehicle should be suitable for injection or aspiration, such as human serum albumin; aqueous buffer solutions, e.g tris(hydromethyl) aminomethane (and its salts), phosphate, citrate, bicarbonate, etc; sterile water; physiological saline; and balanced ionic solutions containing chloride and or dicarbonate salts or normal blood plasma cations such as Ca +2 , Na + , K + , and Mg +2 .
The concentration of the imaging agent according to the present invention in the radiological vehicle should be sufficient to provide satisfactory imaging, for example, when using an aqueous solution, the dosage is about 1.0 to 50 millicuries. The imaging agent should be administered so as to remain in the patient for about 1 to 3 hours, although both longer and shorter time periods are acceptable. Therefore, convenient ampules containing 1 to 10 ml of aqueous solution may be prepared.
Imaging may be carried out in the normal manner, for example by injecting a sufficient amount of the imaging composition to provide adequate imaging and then scanning with a suitable machine, such as a gamma camera.
In a further significant aspect of the present invention, novel N 3 S amide-thiolate ligands are disclosed. These ligands are distinguished from conventional amide-thiolate ligands by having an amine group in the N 3 S core which is rapidly converted to an amide upon complexation. The presence of the amine enhances the initial kinetics of chelate formation while the presence of the final amide provides a more a thermodynamically stable triamide-thiolate complex. Overall, the metal chelate formation kinetics are enhanced.
The "amine group" is preferably part of a pyridine ring containing a lower alkoxyl substituent in the 2 or 4 position. O -dealkylation occurs upon complexation which causes the amine to become a vinylogous amide. Thus, the amine is a masked amide. In the claimed compounds, the amide necessary to form the chelate is masked as an amine by the presence of 2 or 4 alkoxyl substituent in the pyridine ring. Upon initial complex formation, O-dealkylation occurs to regenerate the amide.
The following Generalized structure illustrates a typical N 3 S ligands containing a masked amide group within the scope of the present invention. ##STR47## Where A is an H, alkyl, a functionalized substituent of an α-amino acid, or --(CH 2 ) n' --X, where X is a functional group for coupling the ligand to a biomolecule, n' is from 1 to 10; R 1 or R 2 is a lower alkoxyl group, preferably methyoxyl, and the remaining R 1 or R 2 is H, alkyl, electron withdrawing group, or optionally --(CH 2 ) n' --X if A is not --(CH 2 ) n' --X; A' or A" is H, alkyl, electron withdrawing group, or optionally --(CH 2 ) n' --X if A, R 1 , R 2 is not --(CH 2 ) n' --X; n is 1 or 2; and PG is a protecting group. Examples of possible functional groups for coupling the ligand to a biomolecule include carbonyl, active ester, isocyanate, isothiocyanate, imidate, maleimide or an activated electrophilic center such as C═C, halocarbonyl, halosulfonyl, and haloacetyl. Electron withdrawing groups, such as carboxylic acid, are well known to those skilled in the art and include functional groups containing unsaturation or electronegative atoms, such as halogen.
The protecting group prevents potential oxidation of the sulfur and prevents the sulfur from reacting with other reactive groups in the biologically active molecule during attachment of the ligand. The protecting group remains stable during kit formulation and stable until the metal (radioisotope) is added by the end user for conversion to the chelate. The protecting groups are removed concomitantly during complex formation, i.e., the protecting groups are removed only under labeling conditions and in the presence of the metal. Examples of typical protecting groups known in the art include hemithioacetal groups such as ethoxyethyl, methoxymethyl, substituted and unsubstituted tetrahydrofuranyl and tetrahydropyranyl, acetamidoalkyl such as actetamidomethyl, S-acyl such as S-alkanoyl, S-benzoyl, and S-substituted benzoyl groups.
The following examples are offered to further illustrate the preparation of ligands and radionuclide complexes within the scope of the present invention. These examples are intended to be purely exemplary and should not be viewed as a limitation on any claimed embodiment.
EXAMPLE 1
Preparation of 2-aza-4-[N-(S-benzoyl)mercaptoacetyl-8-[N-(t-butoxy)carbonyl]amino-3-oxo-1-(2-pyridyl)octane
A mixture of 4-amino-2-aza-8-[N-(t-butoxy)carbonyl]-amino-3-oxo-1-(2-pyridyl)octane (1.70 g, 5 mmol) and N-[(S-benzoyl) mercapto]acetoxy-succinimide (1.53 g, 5.5 mmol) in acetonitrile (15 mL) was stirred at ambient temperature for 4 hours. The reaction mixture was poured onto water (100 mL) and kept at 4° to 8° C. (refrigerator) for about 16 hours. The precipitate was collected by filtration, washed well with water, dried, and recrystallized from acetonitrile to give 1.2 g of colorless solid, mp 133°-135° C. Anal. Calcd. for C 25 H 34 N 4 O 5 S: C, 60.70; H, 6.61; N, 10.89; S, 6.26. Found: C, 60.79; H, 6.65; N, 10.91; S, 6.30.
EXAMPLE 2
Preparation of 2-aza-4-[N-(S-tetrahydropyranyl)-mercapto]acetyl-8-N-(t-butoxy)carbonyl]amino-3-oxo-1-(2-pyridyl) octane
A mixture of 4-amino-2-aza-8-[N-(t-butoxy)carbonyl)]amino-3-oxo-1-(2-pyridyl)octane (3.36 g, 10 mmol) and N-[(S-tetrahydropyranyl)mercapto-acetoxy]-succinimide (2.40 g, 10 mmol) in acetonitrile (25 mL) was stirred at ambient temperature for 4 hours. The reaction mixture was poured onto water (100 mL) and extracted with methylene chloride (3×25mL). The combined organic extracts were washed with water, dried (MgSO 4 ), filtered, and the filtrate taken to dryness under reduced pressure. The gummy residue was chromatographed over silica gel (200 g) using chloroform/methanol (95:5) as eluent to give 3.2 g of off-white solid, mp 87°-90° C. 13C--NMR (CDCl 3 )δ171.8, 171.7, 170.0, 156.9, 156.7, 156.3, 149.3, 137.0, 122.5, 121.9, 84.0, 83.6, 79.0, 66.2, 65.7, 53.2, 44.4, 44.3, 40.0, 35.0, 34.6, 31.7, 31.0, 29.4, 28.2, 25.0, 24.9, 22.4, 21.9, 21.6.
EXAMPLE 3
Preparation of 6-aza-4-[N-(S-benzoyl)mercapto]acetyl-5-oxo-7-(2-pyridyl)-heptanoic acid
A mixture of t-butyl 6-aza-4-[N-(S-benzoyl)-mercapto]acetyl-5-oxo-7-(2-pyridyl)heptanoate (2.35 g, 5mmol) and trifluoroacetic acid (5 mL) was kept at ambient temperature for 1 hour. The solution was then poured onto ether (100 mL). The precipitate was then collected by filtration, washed well with ether, and dried to yield 1.5 g of off white solid. 1 H--NMR (DMSO-d 6 ) δ8.49-8.71 (m, 3H), 7.85-8.00 (m, 3H), 7.60-7.70 (m, 1H), 7.40-7.60 (m, 4H), 4.45 (d, 2H), 4.31 (m, 1H), 3.87 (dd, 2H), 2.27 (m, 2H), 1.95 (m, 1H), 1.80 (m, 1H). 13 C--NMR (DMSO-d 6 ) δ191.1, 174.4, 172.0, 167.7, 157.5, 146.7, 140.3, 136.3, 134.5, 129.5, 127.2, 123.5, 122.5, 52.7, 42.9, 32.6, 30.1, 27.0. FAB mass spectrum, m/Z 416 (M+1).
EXAMPLE 4
Preparation of 7-aza-5-N-[(5-benzoyl)mercapto]acetyl-1-N-(t-butoxy-carbonyl) amino-6-oxo-9-(2-pyridyl)nonane
A mixture of N-t-BOC-lysine-2-(2-pyridyl)ethylamide (1.75 g, 5 mmol) and N-[(5-benzoyl)mercapto]acetoxy-succinimide (1.53 g, 5.5 mmol) in acetonitrile (15 mL) was stirred at ambient temperature for four hours. The reaction mixture was poured onto water (100 ml) and cooled in ice-salt bath for two hours. The precipitate was collected by filtration, washed with water, dried, and recrystallized from acetonitrile to give 2.3 g (88%) of colorless solid. m.p. 138°-140° C. Anal. Calcd. for C 26 H 36 N 4 O 5 S: C, 61.36; H, 7.27; N, 10.67; S, 6.10. Found: C, 61.39; H, 7.18; N, 10.62; S, 6.01.
EXAMPLE 5
Preparation of technetium-99 m complex of the ligand in Example 1
A solution of the ligand in Example 1 (130 μL of 0.8 mg/mL stock solution in isopropyl alcohol) was incubated for 10 minutes at pH 12 (25 μL of 0.5M sodium phosphate). The mixture was then transferred to a vial containing stannous chloride solution (25 μL of 4 mg/mL stock solution in 0.05N HCl) and sodium pertechnetate solution (1 mL, 4 mCi/mL). The entire mixture was heated in boiling water bath for 5 minutes. The product was isolated and purified by reverse phase HPLC to give neutral 99m Tc (V) complex in about 50% yield.
EXAMPLE 6
Preparation of technetium-99 m complex of the ligand in Example 2
To a mixture of sodium gluconate (50 mg) and stannous chloride (1.2 mg) in water (1 mL) was added sodium pertechnetate (1 mL, 4 mCi/mL), 0.1N HCl (5 μL), and the ligand in Example 2 (115 μL of 1 mg/mL stock solution in isopropyl alcohol). The entire mixture was heated in boiling water bath for 5 minutes. The product was isolated and purified by reverse phase HPLC to give neutral 99m Tc (V) complex in about 75% yield.
EXAMPLE 7
Preparation of 10-[(S-tetrahydropyranyl)mercapto]-acetamido-5,12-diaza-4,11-dioxo-13(2-pyridiyl)tridecanoic acid
A mixture of 4-(4-amino)butyl-3,6-diaza-2,5-dioxo-1-(S-tetrahydropyranyl)mercapto-7-(2-pyridyl)heptane (790 mg, 2.0 mmol) and S-tetrahydropyranylmercaptoacetic acid (220 mg, 2.2 mmol) in acetonitrile (10mL) was heated under reflux for four hours and stirred at ambient temperature for sixteen hours. The solvent was removed under reduced pressure and the residue was purified by flash chromatography over reverse phase (25 g) eluted with water followed by methanol/water (1:1). Evaporation of the solvent afforded the desired ligand (510 mg) as colorless, amorphous solid. Anal. Calcd. for C 23 H 34 N 4 O 6 S ×0.33 H 2 O: C, 55.20; H, 6.93; N, 11.20; S, 6.40: H 2 O, 1.20Found: C, 54.81; H, 6.99; N, 11.18; S, 6.39: H 2 O, 1.19. Mass spectrum (thermospray) M/Z 495 (M+1).
The choice of protecting groups for the ligands according to the present invention has been found to be important. In particular, finding the proper protecting group for protection of the sulfur moiety has created difficulty in past ligand technology. It has been discovered that the use of hemithioacetal protecting groups such as tetrahydropyrannyl (THP) are especially useful during the labelling procedures.
Labelling of pyridine ligands as described above having a hemithioacetal protecting group has been carried out as shown in the following examples.
EXAMPLE 8
Preparations were made as follows:
To 0.1 mL stannous gluconate (from a lyophilized kit containing 50 mg sodium gluconate and 1.2 mg stannous chloride, and reconstituted with 1.0mL of degassed water) was added 1.0 mL pertechnetate, Tc-99 m (about 3 mCi). The above is allowed to stand for 5 min at room temperature, before it is adjusted for pH with either HCl or NaOH (target Ph were 5, 6, 7 and 8). 0.12 mL of a pyridine ligand (SN 2 Py) (0.88 mg/mL, 33% IPA/water) was then added. The preparations were incubated in a boiling water bath for 5 minutes.
An aliquot of the preparation was injected on an HPLC (C18 reverse phase), and the results of the radioactive profiles were integrated. Radiolabelling yields (RCY) are expressed as a percent of the peak of interest (Tc-99 m SN 2 Py). Recovery studies were performed by measuring the amount of activity injected on the system vs recovered. The pH of the preparations were also measured with a pH electrode.
Example 8: Results
______________________________________Target pH RCY Recovery (%) Measured pH______________________________________5 43.1 90 5.16 53.6 ND 6.07 89.9 84 7.68 86.7 91 8.8______________________________________
EXAMPLE 9
Three preparations were done following the same protocol set forth in Example 8, except that dilute Tc-99 pertechnetate was added to the Tc-99 m in order to carry more Tc mass.
One preparation was a control (prep pH 7) and the two other preparations contained an additional 5 nanomoles of Tc-99 (since 1 mL TcO 4 - is used, the preparation would be made with 5 μM Tc, the highest usually eluted from a Mo-99/Tc-99 m generator). Among these preparations, one was done at 50° C. for 30 min instead of the 100° C. (boiling water bath) for 5 min.
Example 9: Results
______________________________________Preparation RCY Recovery (%) Measured pH______________________________________control 89.9 89 7.3100° C., 5 min 70.2 83 7.6 50° C., 30 min 25.4 79 ND______________________________________
The results above clearly indicate that pyridine ligands having a THP protecting group can be labelled in a wide range of pH conditions ranging from acidic to basic. The preparations made with additional Tc-99 showed somewhat reduced kinetics but still provided good yield of product. This precludes the possibility that the results could be explained by radiolabelling of an impurity of the ligand. Radiolabelling was shown to occur even at reduced temperature.
Based on the above results, it is believed that the pyridine ligand plays a major role in the radiolabelling properties. In addition, it is believed that the THP protecting group, previously thought to be an acid cleavable protector can be used to protect the ligand and allow excellent radiolabelling of the product, even under neutral and basic conditions.
EXAMPLE 10
Preparation of 5-aza-3-(N-t-butoxycarbonyl)amino-1-mercapto-4-oxo-7-(2-pyridyl)-heptane ##STR48##
A mixture of 2-(2-aminoethyl)pyridine (2.44 g, 0.02 mol) and N-t butoxycarbonyl-homocysteinethiolactone (4.22 g, 0.02 mol) in acetonitrile (50 ml) was heated under reflux for 12 hours. Thereafter, the reaction mixture was kept at room temperature for 6 hours by which time colorless crystals had separated. The solid was collected by filtration, washed with cold acetonitrile, and dried. 13 C--NMR (CDCl 3 ) δ171.2, 159.3, 155.4, 149.2, 136.4, 123.3, 121.5, 79.9, 53.7, 38.8, 36.9, 34.8, 32.6, 28.3.
EXAMPLE 11
Preparation of 3-acetamido-5-aza-1-mercapto-4-oxo-7-(2-pyridyl) heptane ##STR49##
A mixture of N-acetylhomocysteinethiolactone (4.77 g, 0.03 mol) and 2-(2-aminoethyl) pyridine (3.66 g, 0.03 mol) in acetonitrile (50 ml) was heated under reflux for 12 hours. The solvent was removed under reduced pressure and the residue was treated with ethyl acetate (50 ml). The precipitate was collected, dried and recrystallized from acetonitrile to give colorless solid. 13 C--NMR (CDCl 3 ) δ1 171.4, 170.6, 159.4, 149.3, 136.6, 123.4, 121.8, 51.7, 38.5, 36.8, 34.9, 32.7, 22.8.
EXAMPLE 12
Preparation of 3-amino-5-aza-1-mercapto-4-oxo-7-(2-pyridyl) heptane ##STR50##
A solution of the butoxycarbonyl derivative from Example 10, (4 g) and trifluoroacetic acid (20 ml) was kept at room temperature for 1 hour. The reaction mixture was poured onto ether (500 ml). The precipitate was collected, washed with ether and dried. The compound was pure enough for the next step.
EXAMPLE 13
Preparation of 5-aza-3-ethylamino-1-mercapto-4-oxo-7-(2-pyridyl) heptane ##STR51##
A solution of diborane in tetrahydrofuran (1M, Aldrich) (60 ml) was added dropwise to an ice-cold solution of the diamide of Example 2 (4 g) in tetrahydrofuran (20 ml). After the addition, the reaction mixture was heated under reflux for 2 hours. The reaction mixture was then cooled in an ice bath and excess diborane was decomposed by dropwise addition of ice-cold water. The solution was taken to dryness under reduced pressure and the residue was redissolved in methylene chloride (100 ml) washed with water (2×100 ml), dried (Na 2 SO 4 ), filtered and the filtrate was taken to dryness under reduced pressure. The residue was chromatographed over silica gel (200 g) using CH 2 Cl 2 /CH 3 OH (9:1) as eluent to furnish the desired compound as colorless gum (1 g). 13 C--NMR (CDCl 3 ) δ174.7, 159.0, 148.9, 137.2, 123.7, 121.9, 61.2, 49.8, 42.3, 38.3, 37.4, 36.8, 20.8, 14.7.
EXAMPLE 14
Preparation of 7-(S-benzoyl) mercapto-2,5-diaza-3,6-dioxo-1-(2-pyridyl) heptane ##STR52##
A mixture of S-(benzoyl)mercaptoacetoxy succinimide (1.4 g) and 1-amino-3-aza-2-oxo-4-(2-pyridyl) butane (0.8 g) in acetonitrile (20 ml) was stirred at room temperature for 1 hour. The white precipitate was collected, washed with water, dried, and recrystallized from acetonitrile to give 700 mg of colorless solid. 13 C--NMR (CDCl 3 ) δ191.9, 168.9, 156.5, 149.2, 137.0, 136.1, 134.3, 128.9, 127.7, 122.5, 122.0, 44.3, 43.3, 32.5.
EXAMPLE 15
99m Tc labelling of the ligand of Example 10 ##STR53##
A mixture of the ligand produced in Example 10 (10 mg) in ethanol (0.9 ml) was treated with 0.01N NaOH (0.1 ml) and technetium tartarate solution (0.1 ml). The entire mixture was heated at 100° C. for 30 minutes. After cooling, the neutral complex was purified by reverse phase HPLC.
EXAMPLE 16
99m Tc labelling of the ligand of Example 14 ##STR54##
A mixture of the ligand produced in Example 14 (10 mg) in ethanol (0.1 ml) and 0.0001N NaOH (0.9 ml) and technetium tartarate solution (0.1 ml) was heated at 100° C. for 45 minutes to yield neutral complex in high yield and purity. No HPLC purification was required.
EXAMPLE 17
Preparation of 5-aza-3-(N-t-butoxycarbonyl)amino-1-S-[(N-ethyl)carbamoyl]mercapto-4-oxo-7-(2-pyridyl)-heptane ##STR55##
A mixture of 2-aminomethyl pyridine (2.44 g, 0.02 mol) and N-t butoxycarbonyl-homocysteinethiolactone (4.22 g, 0.02 mol) in acetonitrile (50 ml) was heated under reflux for 16 hours. Thereafter, the reaction mixture was cooled to room temperature and was treated with ethyl isocyanate (2 ml). The solution was stirred at room temperature for 16 hours. The solvent was removed under reduced pressure and the residue was treated with CH 2 Cl 2 (50 ml) and water (50ml). The organic layer was separated, washed with water, dried (MgSO 4 ), filtered, and the filtrate taken to dryness under reduced pressure to give the desired compound as a pale yellow gum. Purification by silica gel chromatography (ethyl acetate acetone, 4:1) yielded pure ligand (1.2 g) as an off white solid. 13 C--NMR (CDCl 3 ) δ171.6, 156.6, 155.6, 149.0, 136.7, 122.3, 121.7, 80.0, 53.7, 44.6, 36.4, 33.9, 28.3, 26.1, 14.9.
The following examples illustrate exemplary methods of preparing various pyridine derivatives which may be used to prepare ligands within the scope of the present invention.
EXAMPLE 18
The following diagram illustrates the synthesis of a pyridine derivative having a methoxyl substituent in the 2 position. Commercially available 2,6-dichloropyridine is converted to 2-cyano-6-methoxypyridine by successive nucleophilic substitution with cyanide and methoxide followed by catalytic reduction to give compound (A). ##STR56##
The final compound (A) may be used to prepare a ligand within the scope of the present invention in which n=1.
EXAMPLE 19
The following diagram illustrates the synthesis of a pyridine derivative having a methoxyl substituent in the 4 position. The initial 4-chloropyridine starting material is commercially available. The individual reactions are known to those skilled in the art. ##STR57##
Support for the first step conversion of the chloro pyridine to the 2-cyano derivative is found in Yakugaku Zasshi, Vol. 65B, p. 582 (1945). The final compound (B) may be used to prepare a ligand within the scope of the present invention in which n=1.
EXAMPLE 20
The following diagram illustrates the synthesis of a pyridine derivative having a methoxyl substituent in the 2 position. Commercially available 2,6-dichloropyridine is converted to α-cyano-α-methylthio-6-methoxypyridine by successive nucleophilic substitution with the anion of methylthioacetonitrile and methoxide. Dethiation and reduction of the nitrile is accomplished with Ra--Ni in a single step to give compound (C). ##STR58## The final compound (C) may be used to prepare a ligand within the scope of the present invention in which n=2.
The following examples are offered to further illustrate the synthesis of potential triamide-thiolate ligands within the scope of the present invention.
EXAMPLE 21
In this example, compounds A (for n=1) or B (for n=2) are used as starting materials for the synthesis of ligands containing masked amides within the scope of the present invention. The other starting material, Z-glutamic acid γ-benzyl ester, is commercially available. The individual reactions are known to those skilled in the art. ##STR59## The same reaction conditions described above may be used when the alkoxyl group is in the 4 position (for compound B).
The quartenization of nitrogen heterocycles followed by O-dealkylation according to the Hilbert and Johnson reaction (alkoxyl group in the 2 position) reported in J. Amer. Chem. Soc., Vol. 52, p. 2001 (1930) as shown below: ##STR60## Where R is alkyl or acetal and X is a halide or anionic counter ion. Dealkylation of the alkoxyl group in the 4 position is reported by Fry et al., J. Chem. Soc. p. 5062 (1960) as shown below: ##STR61## Where X is O or S, and when X is O, then R is phenyl and when X is S, then R is CH 3 .
The ligands are labeled according to standard labeling techniques. The following diagram illustrates the O -dealkylation and formation of a vinylogous amide for ligands in which the alkoxyl substituent is in the 2 position. ##STR62##
The following diagram illustrates the O-dealkylation and formation of a vinylogous amide for ligands in which the alkoxyl substituent is in the 4 position. ##STR63##
As described above, the amide-thiolate ligands within the scope of the present invention may be coupled to biomolecules according to standard procedures known in the art. The conjugated biomolecules are then labelled with suitable radionuclides and administered to a patient for diagnostic imaging or therapeutic use.
After the amide-thiolate ligands of the present invention are prepared and labelled according to the procedure described above, the compounds may be used with a pharmaceutically acceptable carrier in conventional diagnostic imaging procedures. In this procedure, a diagnostically effective quantity of the compound, for example in the form of an injectable liquid, is administered to a warm-blooded animal and then imaged using a suitable detector, e.g. a gamma camera. Images are obtained by recording emitted radiation of tissue or the pathological process in which the radioactive peptide has been incorporated, which in the present care of tumors, thereby imaging at least a portion of the body of the warm-blooded animal.
Pharmaceutically acceptable carriers for either diagnostic or therapeutic use include those that are suitable for injection or administration such as aqueous buffer solutions, e.g. tris(hydroxymethyl)aminomethane (and its salts), phosphate, citrate, bicarbonate, etc., sterile water for injection, physiological saline, and balanced ionic solutions containing chloride and/or bicarbonate salts of normal blood plasma cations such as Ca +2 , Na + , K + and Mg 2+ . Other buffer solutions are described in Remington's Practice of Pharmacy, 11th edition, for example on page 170. The carriers may contain a chelating agent, e.g. a small amount of ethylenediaminetetraacetic acid, calcium disodium salt, or other pharmaceutically acceptable chelating agents.
The concentration of labelled biomolecule and the pharmaceutically acceptable carrier, for example in an aqueous medium, varies with the particular field of use, A sufficient amount is present in the pharmaceutically acceptable carrier in the present invention when satisfactory visualization of the tumor is achievable or therapeutic results are achievable.
The inventions described herein may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | The present invention relates particularly to novel pyridine based nitrogen-sulfur ligands that are suitable for complexing with a radionuclide, and are useful as general imaging agents for diagnostic purposes, novel aminothiol ligands that are suitable for complexing with a radionuclide, and are useful as general imaging agents for diagnostic purposes, and amide-thiolate ligands having improved metal chelate formation kinetics. The amide-thiolate ligands include an amine which converts to a vinylogous amide upon complexation, thereby providing rapid complexation and thermodynamic stability. The ligands may be used for post formed labeling of biological substances for use in the fields of diagnosis and therapy. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to supports, and more particularly to a swiveling support for supporting an elongated rifle or the like in a horizontal orientation.
BACKGROUND OF THE INVENTION
[0002] Hunters frequently avail themselves of hunting blinds when hunting game. A hunting blind is a small shelter, typically built rigid and fixed in configuration. The hunting blind serves to shelter a hunter and conceal the hunter from game animals. A hunting blind has windows through which projectiles are fired.
[0003] Hunting can be difficult in that a weapon must be held in carefully controlled position until the moment of firing. Any deviation from the controlled position can cause the hunter to miss his or her target. Weapons used by hunters can include long rifles, which are difficult to hold steady merely by manual grasp.
[0004] Gun rests have been provided to address this problem. A gun rest may be fixed to a suitable structural portion of the hunting blind, such as a vertical wall. However, construction of hunting blinds typically does not anticipate any specific type of gun rest. Hence it falls to the gun rest to conform to and accommodate the hunting blind. There exists a need for a gun rest which is well adapted for mounting to a hunting blind, accommodating a hunter's weight and preferred body position, and is suitable for use with diverse styles of guns.
SUMMARY OF THE INVENTION
[0005] The present invention addresses the above stated situation by providing a gun rest which readily mounts to a hunting blind, provides a flat support table unencumbered by complicated construction or by projections, thereby accommodating diverse placement of a gun and different body positions when leaning on the gun support, and which accommodates different gun styles and configurations.
[0006] To these ends, the gun rest includes a mounting unit for mounting to a wall of the hunting blind, and a support unit for supporting a gun and a body of a person using the gun. A swivel joint accommodates swivel of the support unit relative to the mounting unit about a vertical axis, thereby enabling the gun to fire through any one of the windows of the hunting blind. The mounting unit includes a foot located to be able to contact a floor of the hunting blind, thereby reducing loads imposed on mounting bolts securing the mounting unit to the wall of the hunting blind. The swivel joint may comprise an upper socket and lower socket on the mounting unit, and corresponding fingers on the swiveling support unit.
[0007] The support unit comprises a support member including a flat planar horizontal support surface, enabling a variety of gun supports to be laid thereon, with the hunter supporting some of his or her upper body on the support unit as well as the gun.
[0008] It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes.
[0009] This and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:
[0011] FIG. 1 is a perspective view of a swiveling gun rest mounted in a hunting blind, according to at least one aspect of the invention;
[0012] FIG. 2 is an exploded view of two major components of the swiveling gun rest of FIG. 1 ; and
[0013] FIG. 3 is a perspective exterior view of the hunting blind shown in FIG. 1 .
DETAILED DESCRIPTION
[0014] Referring first to FIGS. 1 and 2 , according to at least one aspect of the invention, there is shown a swiveling gun rest 100 comprising a mounting unit 102 configured to be mounted on a surface (e.g., a wall 204 ) of a hunting blind 200 or the like. Mounting unit 102 comprises a mast 104 including an upper end 106 , a lower end 108 , and a bracket member 110 attached to the lower end 108 . Bracket member 110 includes an adjuster configured to raise and lower bracket member 110 relative to mast 104 . Swiveling gun rest 100 also comprises a support unit 112 for supporting a gun (not shown) and a body of a person (not shown) using the gun. Support unit 112 comprises a support member 114 including a flat planar horizontal support surface 116 . Swiveling gun rest 100 further comprises at least one swivel joint configured to swivel support unit 112 relative to mounting unit 102 about a vertical axis 118 when mounting unit 102 is on the surface of hunting blind 200 .
[0015] The adjuster will be described hereinafter. Axis 118 is an axis of rotation of support unit 112 as the latter swivels on mounting unit 102 . Swivel joints will be further explained hereinafter.
[0016] It should be noted at this point that orientational terms such as upper and lower refer to the subject drawing as viewed by an observer. The drawing figures depict their subject matter in orientations of normal use, which could obviously change with changes in body posture and position. Therefore, orientational terms must be understood to provide semantic basis for purposes of description only, and do not imply that their subject matter can be used only in one position. For example, axis 118 is vertical in an orientation of normal use illustrated in FIGS. 1 and 2 .
[0017] Support member 114 is used to support a gun, cushions or other structure holding the gun in an operable position, and weight of the upper body of a person using the gun. To comfortably and stably support these items, support member 114 comprises a yielding material, such as cotton batting or an open cell or closed cell synthetic resinous foam. A fabric or other cover (not shown) may be provided to protect the yielding material from contamination. Support member 114 has a length 122 ( FIG. 1 ) between two feet and four feet, and a width 120 between six and fifteen inches.
[0018] Support unit 102 comprises a frame 124 . Support member 114 is coupled to frame 124 . Support member 114 is removably mounted to frame 124 of support unit 112 . Support unit 112 comprises a plurality of fasteners 126 ( FIG. 2 ) removably securing support member 114 to frame 124 of support unit 112 . Referring principally to FIG. 2 , frame 124 of support unit 112 comprises a vertical first member 128 proximate mast 104 of mounting unit 102 , a horizontal second member 130 fixed to vertical first member 128 , and a spanning member 132 fixed to vertical first member 128 and to horizontal second member 130 . Horizontal second member 130 of frame 124 of support unit 112 comprises a frame upper surface 134 and a plurality of laterally projecting tabs 136 having tab upper surfaces 138 coplanar with frame upper surface 134 . Vertical first member 128 of frame 124 has a height between fifteen inches and twenty-five inches. Horizontal second member 130 of frame 124 has a length between twenty-five and forty inches. In FIG. 2 , the height is vertical and the length is horizontal.
[0019] Unless otherwise indicated, the terms “first”, “second”, etc., are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the times to which these terms refer. Moreover, reference to, e.g., a “second” item does not either require or preclude the existence of, e.g., a “first” or lower-numbered item, and/or, e.g., a “third” or higher-numbered item.
[0020] In the example of swiveling gun rest 100 illustrated in FIGS. 1 and 2 , the swivel joint comprises at least one socket 140 on one of mounting unit 102 and support unit 112 , and at least one finger 142 rigidly coupled to the other one of mounting unit 102 and support unit 112 . Finger 142 is dimensioned and configured to slidably penetrate socket 140 in close cooperation therewith. In the example of swiveling gun rest 100 illustrated in FIGS. 1 and 2 , the swivel joint comprises a first socket 140 on one of mounting unit 102 and support unit 112 , a second socket 140 axially aligned with the first socket 140 on the one of mounting unit 102 and support unit 112 , a first finger 142 on the other one of mounting unit 102 and support unit 112 , and a second finger 142 axially aligned with the second socket 140 on the other one of mounting unit 102 and support unit 112 . The first socket 140 and first finger 142 are proximate upper end 106 of mast 104 , and the second socket 140 and second finger 142 are proximate lower end 108 of mast 104 . Locating one socket 140 and associated finger 142 at each end of 128 results in the most stable support arrangement for support unit 112 , in that torques applied to potentially one swivel joint are minimized by distribution over two such joints. Spreading the two joints apart vertically further reduces maximum loading at any one point along mast 104 .
[0021] Also, using sockets 140 and associated fingers 142 enables ready assembly of swiveling gun rest 100 after mounting unit 102 is fixed to hunting blind 200 . Additionally, support unit 112 may be readily removed from hunting blind 200 to dissuade likelihood of theft or vandalism.
[0022] Foot 110 of mounting unit 102 comprises a horizontal surface 144 engaging floor 202 of hunting blind 200 and a vertical surface 146 engaging a vertical wall 204 of hunting blind 200 when horizontal surface 144 engages floor 202 . Mounting unit 102 comprises an adjuster selectively and adjustably coupling foot 110 to mast 104 , wherein direction of adjustability is the same as that of axis 118 of rotation of the at least one swivel joint. In the example of FIGS. 1 and 2 , the adjuster comprises telescoping fit of mast 104 with a cooperating tube 148 of foot 110 , and a setscrew 150 which threads to mast 104 . Setscrew 150 clamps mast 104 and cooperating tube 148 together at any selected mutual position. Adjustment of foot 110 can reduce some of the weight that would otherwise be imposed on fasteners used to affix mounting unit 102 to vertical wall 204 .
[0023] Mast 104 of mounting unit 102 comprises a plurality of laterally projecting tabs 152 each bearing at least one hole 154 for receiving a fastener (not shown) to accommodate mounting mounting unit 112 to vertical wall 204 of hunting blind 200 .
[0024] The invention may be thought of either as swiveling gun rest 100 , or alternatively, as hunting blind 200 incorporating swiveling gun rest 100 .
[0025] Referring also to FIG. 3 , hunting blind 200 incorporating swiveling gun rest 100 may comprise a shelter structure including a roof 206 , and at least one vertical wall 204 having at least one window 208 , and swiveling gun rest 100 for hunting blind 200 . Swiveling gun rest 100 comprises mounting unit 102 for mounting to the at least one vertical wall 204 of hunting blind 200 . Mounting unit 102 comprises mast 104 including upper end 106 , lower end 108 , and foot 110 at lower end 108 . Foot 110 is located to be able to contact an upwardly facing ground surface of hunting blind 200 . Swiveling gun rest 100 further comprises support unit 112 for supporting a gun (not shown) and a body of a person (not shown) using the gun, support unit 112 comprising support member 114 including flat planar horizontal support surface 116 . Swiveling gun rest 100 further comprises at least one swivel joint accommodating swivel of support unit 112 relative to mounting unit 102 about vertical axis 118 . Flat planar horizontal support surface 116 is aligned with a window 208 such that a gun supported on flat planar horizontal support surface 116 fires through window 208 . Preferably, windows 208 are distributed about the perimeter of hunting blind 200 to provide three hundred sixty degrees of aiming coverage of the environs of hunting blind 200 .
[0026] In the example of FIGS. 1 and 3 , hunting blind 200 incorporating swiveling gun rest 100 comprises a shelter structure including roof 206 , floor 202 , and four vertical walls 204 between roof 206 and floor 202 . Each one of vertical walls 204 has a window 208 . Hunting blind 200 comprises swiveling gun rest 100 comprising mounting unit 102 for mounting to one vertical wall 204 of hunting blind 200 . Mounting unit 102 comprises mast 104 including upper end 106 , lower end 108 , and foot 110 at lower end 108 . Foot 110 is located to be able to contact floor 202 of hunting blind 200 . Hunting blind 200 comprises support unit 112 for supporting a gun (not shown) and a body of a person (not shown) using the gun, support unit 112 comprising support member 114 including flat planar horizontal support surface 116 and at least one swivel joint accommodating swivel of support unit 112 relative to mounting unit 102 about vertical axis 118 . Flat planar horizontal support surface 116 is aligned with each one of windows 208 such that a gun supported on flat planar horizontal support 116 surface fires through any one of windows 208 .
[0027] Although presented thus far as having four vertical walls 204 , hunting blind 200 may have fewer or more vertical walls 204 . For example, hunting blind 200 may be open at one end where it is anticipated that hunting blind 200 will be pushed against a bluff or other vertical environmental surface, which may render at least one of the four vertical walls unnecessary. Alternatively, a single curved wall (not shown) may replace the four discrete vertical walls 204 . Floor 202 of hunting blind 200 may be eliminated if ground conditions are deemed sufficient as not to warrant floor 202 . Therefore, reference to an “upwardly facing ground surface”, where the term is applied to hunting blind 200 , will be understood to encompass both floor 202 and also natural ground surfaces where floor 202 is absent.
[0028] In addition to hunting blinds, swiveling gun rest 100 may be mounted on or incorporated into other structures (none shown), such as houses, garages, sheds, carports, fences, shooting range structures, fences, docks, piers, vehicles, boats, and other structures, both stationary and mobile, presenting a generally vertical surface for mounting.
[0029] Although the invention has been described in terms of certain components being referred to in either the singular or the plural, other arrangements are possible. For example, hunting blind has been presented as comprising four walls. It would be possible to have a single curved wall instead. Alternatively, in a hunting blind adapted to be pushed against a bluff or other natural vertical surface, one or more walls may be omitted, as may be floor.
[0030] While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all modifications and equivalent arrangements which are possible.
[0031] It should be understood that the various examples of the apparatus(es) disclosed herein may include any of the components, features, and functionalities of any of the other examples of the apparatus(es) disclosed herein in any feasible combination, and all of such possibilities are intended to be within the spirit and scope of the present disclosure. Many modifications of examples set forth herein will come to mind to one skilled in the art to which the present disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.
[0032] Therefore, it is to be understood that the present disclosure is not to be limited to the specific examples presented and that modifications and other examples are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated drawings describe examples of the present disclosure in the context of certain illustrative combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative implementations without departing from the scope of the appended claims. | A swiveling gun rest is disclosed, comprising a mounting unit for mounting to a surface of a hunting blind, and a swiveling support unit for supporting a gun and a body of a person using the gun. The mounting unit may include a mast having a foot able to contact a floor of the hunting blind. A swivel joint accommodates swivel of the support unit about a vertical axis, so as to be able to fire through windows of the hunting blind. The foot may accommodate the combined weights of the gun rest, gun, and a portion of the body weight of the person. The swivel joint may comprise a plurality of sockets fixed to the mounting unit and an equal number of fingers fixed to the support unit, the fingers configured to occupy the sockets. The support unit may comprise a frame and a cushion atop the frame. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of and priority to German patent application no. DE 10 2008 037 612.4-14, filed on Nov. 28, 2008. The disclosure of the above application is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The invention relates to a method for producing highly dimensionally accurate, deep-drawn half shells with a base region, a body region and a flange region, wherein a pre-formed half shell is firstly formed from a blank and is then shaped into the finally formed half shell, wherein the pre-formed half shell has excess blank material due to of its geometric shape and wherein owing to the excess material during the shaping of the pre-formed half shell into its final shape the half shell is compressed into the finally formed half shell by at least one further pressing process. The invention also relates to a tool set for producing a highly dimensionally accurate deep-drawn half shell with flange regions with a first tool for producing a pre-formed half shell, the first tool comprising a first bottom die, and with a second tool for producing the finally formed half shell, the second tool comprising a second bottom die, the shape of which substantially corresponds to the negative of the outer shape of the finally formed half shell.
BACKGROUND
Closed hollow profiles, which have cross-sections and material thicknesses specially adapted to the application are increasingly being used in motor vehicles. Closed hollow profiles were previously generally produced in that firstly a tube is formed, the tube is subjected to corresponding bending and pre-forming processes and then a hydro-forming of the pre-bent or pre-formed tube into the final shape of the closed hollow profile takes place. On the one hand, not all components can be produced in this manner as in hydro-forming local elongations of the material are exceeded and thus cracks may form. In addition, there may be a non-manageable formation of folds during the hydro-forming. Moreover, the method steps previously used to produce a closed hollow profile adapted to the application are very complex and therefore expensive. A closed hollow profile may, in principle, also be produced from two deep-drawn half shells. During the deep-drawing of a blank, stresses are, however, introduced into the blank and lead to a spring-back of the half shell. The spring-back of the half shells makes the precise positioning of the half shells in a bottom die for welding the half shells into a closed hollow profile more difficult.
Assembling half shells which spring back strongly in a vehicle structure is very complex, however, because of the strong distortion. These parts alternatively have to be straightened and this entails very high costs.
A method for press-forming half shells, which are then welded to form a closed hollow profile, is known from the published European patent application EP 1 792 671 A1. The object of the European patent application mentioned is to provide half shells with thickened edge regions between the base region and the body. For this reason, a pre-formed half shell is firstly produced from a blank which provides excess material which is pressed during shaping into the final form from the base region into the edge regions between the body and the base region of the half shell. In comparison, the present invention deals with reducing the spring-back of deep-drawn half shells.
SUMMARY OF THE INVENTION
Proceeding from this, the present invention is based on the technical problem of providing a method and a tool set for producing highly dimensionally accurate flanged half shells, with which, with a low outlay for apparatus, highly dimensionally accurate flanged half shells can be economically produced.
This technical problem is achieved according to the invention in that the pre-formed half shell has the excess blank material in the transition region between the body region and flange region. This transition region is taken to mean the body region adjoining the flange region and the flange region adjoining the body region. When producing half shells by simple deep drawing, strong geometrical deviations from the intended shape frequently occur in the transition region. This transition region is therefore particularly critical when producing highly dimensionally accurate flanged half shells. For example, deep drawing in the transition region may lead to the formation of cracks or premature material fatigue. Such problems are reliably avoided by the excess material in the transition region.
According to a preferred embodiment, the pre-formed half shell has the excess blank material at least in the base region and in the body region or in the base region and in the flange region, so the half shell is highly dimensionally accurate after the second pressing process in its entire cross-section and a spring-back is prevented. Furthermore, the finally formed half shell has a shape corresponding very precisely to the geometry of the second bottom die. The invention is based on the recognition that to produce highly dimensionally accurate flanged half shells, it is necessary to compress the pre-formed half shell over its entire cross-section. Therefore, the excess material required for compression also has to be available over the entire cross-section.
The excess blank material is provided in a further preferred embodiment of the invention in that the central flange radius in the transition region between the body region and flange region in the pre-formed half shell is greater or smaller than in the final shape. The central flange radius is taken to mean the radius of the circle, with the periphery of which the course of the half shell best coincides in the transition region between the body region and flange region. It is thus unnecessary for the transition region of the half shell between the body region and flange region to actually be arc of a circle-shaped. Thus, the transition region may, for example, have the shape of an elliptical arch, a parabola or another shape. The provision of excess blank material is achieved in a very simple manner by this embodiment.
Furthermore, a very simple first bottom die can be used to produce the pre-formed half shell. The formation of a larger flange radius is advantageous, in particular, in the case of large drawing depths and leads to a smaller wall thinning of the pre-formed half shell in the body region. Formation of a smaller flange radius is advantageous for the lateral wall ironing of the flange region and thus reduces the spring-back of the pre-formed half shell. To reduce the spring-back of the pre-formed half shell, additional measures may also be provided in both variants, such as, for example, body wall ironing, via flange moderation by means of moderating crimps/beads and/or by adjusting the forces of the holding-down device.
A further improvement of the dimensional accuracy of the half shell, in particular in the flange region, is achieved in a further preferred embodiment in that the material flow of the half shell at the flange edges of the half shell is blocked, at least intermittently, during the pressing process. This means that no blank material is pressed out of the pressing region and thus the entire excess blank material is completely compressed into the finally formed half shell, so the half shell is reinforced in particular at the critical points for the dimensional accuracy.
The blocking of the material flow of the half shell to the outside can be achieved in a particularly preferred manner by a blocking wall provided on the calibration top die used for the pressing process. This, on the one hand, has the advantage that no additional moveable component has to be provided to block the material flow to the outside. On the other hand, it is thus achieved that the blocking wall blocking the material flow travels into the position provided for blocking precisely during the pressing process bringing about the material flow.
In a further preferred embodiment, the pre-formed half shell is trimmed in the flange region before or during the pressing process in the same bottom die. This means that the half shell already has its completely finished final shape after the pressing process. This saves a working step and therefore time and costs.
The precision and cleanness of the trimming of the half shell is achieved in a further preferred embodiment in that the pre-formed half shell is fixed by a holding-down device in the flange region before trimming. This prevents a change of the position of the half shell during trimming and therefore the formation of an unclean cutting edge. An advantageous control of the material flow in the half shell is achieved by maintaining the fixing during the pressing process with simultaneous blocking of the material flow to the outside. Thus the fixing during the pressing process leads to a material flow of the excess material from the flange region into the transition region between the body region and flange region. Furthermore, the pre-formed half shell is reliably held in the second bottom die by the fixing so the calibration top die of the second bottom die can travel more precisely into the bottom die.
A particularly precise and clean cutting edge in the flange region of the half shell is achieved in a further preferred embodiment by the use of a laser for trimming the flange region.
The blocking of the material flow of the half shell to the outside is blocked in a further preferred embodiment by the cutting top dies carrying out the trimming. If the half shell in the second bottom die is trimmed, this is particularly advantageous as no additional components are necessary to block the material flow to the outside. This allows the method to be carried out more easily, faster and more economically.
The method according to the invention is particularly suitable for producing half shells made of steel or a steel alloy. Therefore, the blank to produce the pre-formed half shell in a preferred embodiment consists of steel or a steel alloy.
The technical problem is furthermore achieved by a tool set in that the bottom die of the first tool in the transition region between the body region and flange region differs from the shape of the bottom die of the second tool in such a way that the pre-formed half shell in the transition region has more material than is required for the finally formed half shell. During deep-drawing, in particular in the transition region between the body region and flange region of the half shell, strong geometric deviations frequently occur. The tool set according to the invention means that the half shell pre-formed in the first bottom die differs, in particular in this region, from the shape of the second bottom die and therefore excess material is available in the second bottom die during the pressing process and leads to a high dimensional accuracy in this region.
According to a first embodiment, the bottom die of the first tool deviates at least in the base region and in the body region or in the base region and in the flange region from the shape of the bottom die of the second tool in such a way that the pre-formed half shell in the base region and in the body region or in the base region and in the flange region has more material than is required for the finally formed half shell. In the pressing process, a material flow of the excess blank material is produced in the second bottom die in order to orientate the stresses in the blank material which then counteract an uncontrolled spring-back. Moreover, the half shell is to be reinforced by the material flow in the regions otherwise thinned by the deep-drawing. This leads to a high dimensional accuracy of the finally formed half shell. The deviations of the shape of the first bottom die from the shape of the second bottom die can thus be formed as undulating, convex or concave, inward or outward bulges.
The deviations of the shape of the first bottom die from the shape of the second bottom die are achieved in a further preferred embodiment in that the bottom die of the first tool in the transition region between the body region and flange region has a larger or smaller flange radius than the bottom die of the second tool. The pre-formed half shell inserted into the second bottom die, in the transition region between the body region and the flange region, thus does not rest on the second bottom die, but has a deviating course with an increased material quantity. The latter is produced in the case of a larger flange radius owing to the extended flange region, and with a smaller flange radius, owing to the relatively large curvature length in the transition region between the body region and flange region. During the pressing process, the half shell is pressed onto the second bottom die and the excess blank material reinforces the half shell above all in the transition region.
So that the excess blank material remains completely in the second bottom die during the pressing process and thus leads to a reinforcement and therefore higher dimensional accuracy of the half shell, the second tool comprises means in a preferred embodiment which block the material flow to the outside, at least intermittently during the pressing process of a half shell to be shaped into the final shape on the flange edges of a component inserted into the second tool.
This can be achieved in a further preferred embodiment in that the second tool comprises a calibration top die and a blocking wall for blocking the material flow or a cutting top die for the flange trimming with an integrated blocking wall. The calibration top die and the blocking wall may, in this case, form a unit or be moved separately. When providing a cutting top die, the half shell is directly trimmed in the second bottom die. The work sequence can thus be reduced by one working step. The cutting top die is also suitable, in particular, for the integration of the blocking wall, as the latter thus does not need to be moved individually.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention are described in more detail in the description of some embodiments, reference being made to the accompanying drawings, in which:
FIG. 1 shows an embodiment of the first tool of a tool set according to the invention for producing a pre-formed half shell from a blank,
FIG. 2 shows a half shell pre-formed in the first bottom die,
FIG. 3 shows a first embodiment of the second tool of a tool set according to the invention with a pre-formed half shell inserted therein, produced with a first tool of a tool set according to the invention,
FIG. 4 shows a first embodiment of the second tool from FIG. 3 with a pre-formed half shell inserted therein, produced with a further first tool of a tool set according to the invention,
FIG. 5 shows a second embodiment of the second tool of a tool set according to the invention with a pre-formed half shell inserted therein, produced and trimmed with a first tool of a tool set according to the invention,
FIG. 6 shows a third embodiment of the second tool of a tool set according to the invention with a pre-formed half shell inserted therein, produced and trimmed with a first tool of a tool set according to the invention and
FIG. 7 shows a finally formed half shell produced with a tool set according to the invention.
DESCRIPTION
The first tool 2 of an embodiment of a tool set according to the invention for producing a pre-formed half shell from a blank 4 , shown in FIG. 1 , comprises a first bottom die 6 and a deep-drawing top die 8 . The general shape of the inside 10 of the bottom die 6 is similar to the shape of the outside of the finally formed half shell to be produced with the tool set. In the transition region 14 between the body region 16 and the flange region 18 of the bottom die 6 and in the base region 12 , the inside 10 of the bottom die 6 deviates with respect to its shape, however, from the shape of the outside of the finally formed half shell to be produced with the tool set. Thus, the inside 10 of the bottom die 6 in the base region 12 has an undulating shape. Alternatively, a simple concave or convex shape or another shape deviating from the intended shape of the base region or the finally formed half shell is also conceivable. Furthermore, the flange radius in the transition region 14 and the height of the shape, in other words the distance between the base region 12 and the flange region 18 , is increased. Alternatively, a bottom die is conceivable, in which the flange radius is reduced, but the height is not increased. The deep-drawing top die 8 has a shape adapted to the shape of the bottom die 6 , so the blank 4 is deep drawn by lowering the deep-drawing top die 8 into the bottom die 6 to form a pre-formed half shell.
FIG. 2 shows a pre-formed half shell 24 after deep drawing with the first tool shown in FIG. 1 . The outside 26 of the pre-formed half shell 24 substantially corresponds to the inside 10 of the bottom die 6 , but deviates through spring-back from the precise shape of the inside 10 of the bottom die 6 . In the transition region 30 between the body region 32 and the flange region 34 , the pre-shaped half shell 24 has an enlarged flange radius 36 . The base region 28 of the pre-formed half shell 24 is undulating in accordance with the shape of the base region 12 of the bottom die 6 .
The second tool 42 shown in FIG. 3 of a tool set according to the invention comprises a second bottom die 44 , a calibration top die 46 and a holding-down device 48 . A pre-formed half shell 50 , which was produced by the tool shown in FIG. 1 , is inserted into the bottom die 44 . The shape of the inside 52 of the bottom die 44 corresponds to the shape of the outside of the finally shaped half shell to be produced. The half shell 50 therefore does not rest completely on the inside 52 of the bottom die 44 , but stands away from the inside 52 of the bottom die 44 , in particular, in the base region 54 owing to its undulating shape and, in the transition region 56 between the body region 58 and flange region 60 and in the flange region 60 owing to the greater flange radius in the transition region 56 . The height of the pre-formed half shell 50 is thus greater than the height of the finally formed half shell to be produced. The pre-formed half shell 50 , owing to these regions standing away, has excess blank material which is distributed during the lowering of the calibration top die 46 by a material flow on the half shell and leads to a high dimensional accuracy of the finally shaped half shell. The calibration top die 46 has a shape corresponding to the inside of the half shell to be produced. A cutting top die 62 with a cutting edge 64 is integrated into the calibration top die 46 . When lowering the calibration top die 46 , the pre-formed half shell 50 is thus trimmed in the flange region 60 by the cutting edge 64 on the edge 65 of the bottom die 44 to the intended size. The bottom die 44 , in the region of the cutting top die 62 , has a recess 66 , so the cutting die 62 can be lowered and the cut-off piece of the pre-shaped half shell can fall down. The pre-formed half shell 50 in the flange region 60 is fixed by the holding-down device 48 and this leads to a very clean trim of the pre-formed half shell 50 by the cutting edge 64 . In a preferred manner, the calibration top die 46 with the cutting top die 62 is firstly positioned at an adequate height above the pre-formed half shell 50 in the bottom die 44 . It thus has no contact with the base region and the flange region of the pre-formed half shell 50 . The holding-down device 48 is then moved down, for example, by means of sleeves let into the calibration top die and fixes the pre-formed half shell 50 in the flange region 60 . When using a pre-formed half shell 50 with the greater flange radius this leads to an arcuate deformation of the pre-formed half shell 50 in the flange region. With a pre-formed half shell 50 with a smaller flange radius no such deformation occurs and there is therefore a cleaner trim. This is advantageous, in particular in the case of greater sheet metal thicknesses. Finally, the calibration top die 46 and the cutting top die 62 move down completely. In the process, the cutting top die 62 firstly cuts off the projecting flange region of the pre-shaped half shell 50 and blocks the material flow of the blank material to the outside during the further downward movement. The pre-formed half shell 50 is compressed over its entire cross-sectional area by the calibration top die 46 into the finally formed half shell by the excess blank material in the transition region 30 as well as in the base region 54 and in the flange region 60 or in the base region 54 and in the body region 58 of the half shell 50 . Said half shell can only change with respect to its sheet metal thickness during the compression process and is therefore formed with good dimensional accuracy.
FIG. 4 shows the second tool 42 from FIG. 3 . A pre-formed half shell 72 produced by means of a second embodiment of the first tool of a tool set according to the invention is inserted into the bottom die 44 . The pre-formed half shell 72 differs from the pre-formed half shell 50 shown in FIG. 3 in that the transition region 74 between the flange region 76 and the body region 78 has a smaller flange radius than the bottom die 44 . Furthermore, the height of the pre-formed half shell 72 coincides with the height of the finally formed half shell to be produced and therefore with the depth of the bottom die 44 . Owing to the smaller flange radius, the pre-formed half shell 72 in the transition region 74 does not rest on the inside 52 of the bottom die 44 . Thus, excess blank material is available at this point owing to the extended curvature region during the lowering of the calibration top die 46 .
The second tool of a tool set according to the invention shown in FIG. 5 , in contrast to the second tool 42 shown in FIG. 3 , has no holding-down device and no cutting edge. Instead of a cutting top die, the calibration top die 86 has a blocking wall 88 . A pre-formed half shell 92 is inserted into the bottom die 90 . In contrast to the pre-formed half shell 50 shown in FIG. 3 , the pre-formed half shell 92 in the flange region 94 already has the size of the finally formed half shell to be produced. This is achieved, for example, in that a pre-formed half shell produced by a first tool is trimmed in a separate working step before insertion into the bottom die 90 . In this manner, the structure of the second tool and the method sequence are simplified, as no holding of the calibration or cutting top die in an intermediate position is necessary to lower the holding-down device.
The second tool 102 of a tool set according to the invention shown in FIG. 6 differs from that shown in FIG. 5 in that the blocking wall 104 is configured as a separate part from the calibration top die 106 and can be moved independently of the calibration top die 106 .
A finally formed half shell 112 produced by a tool set according to the invention is shown in FIG. 7 . In particular in the transition region 114 between the body region 116 and flange region 118 as well as in the transition region 120 between the base region 122 and flange region 118 , it has high dimensional accuracy and great stability. | A method for producing highly dimensionally accurate, deep-drawn half shells with a base region, a body region and a flange region, includes firstly forming a pre-formed half shell from a blank and then shaping the pre-formed half shell into a finally formed half shell, wherein the pre-formed half shell has excess blank material due to its geometric shape and wherein, owing to the excess material during the shaping of the pre-formed half shell into its final shape the half shell is compressed into the finally formed half shell by at least one further pressing process. The method requires that the pre-formed half shell has excess blank material in a transition region between the body region and flange region. | 1 |
BACKGROUND OF THE DISCLOSURE
This disclosure is directed to a formation testing tool and particularly highlights certain methods of operations thereof. After an oil well has been partly drilled and has passed through formations which are thought to be producing formations, one of the next steps in the completion procedure of the well is to perform various and sundry test on formations penetrated by the oil well. One of the test techniques is to lower a formation testing tool into the oil well. Tests can then be performed for the purpose of making certain measurements (e.g. formation pressure) of interest relating to the formation. An exemplary formation testing tool is described in U.S. Pat. No. 4,375,164 assigned to the assignee of the present disclosure. As described in that particular disclosure, the tool is adapted to be lowered into the well borehole, supported on the armored logging cable which includes several conductors for providing power to the tool and surface control of the logging tool. The logging cable extends to the surface where it passes over a sheave and is stored by spooling onto a reel or drum. The conductors in the armored logging cable connect from surface control apparatus and power supplies. They also connect to a surface recording system.
One procedure known heretofore is to lower the formation testing tool a specified depth in the well. At that depth, a backup shoe is extended on one side of the formation tester and formation testing apparatus is extended diametrically opposite the backup shoe. The formation testing equipment includes a snorkel system. Primarily, this involves a surrounding elastomeric sealing pad which isolates an extendable snorkel which penetrates the formation to a specified depth. The snorkel is isolated from fluid and pressure in the well borehole to be able to test the formation only. That is, testing of the formation is conducted while isolating the formation tester from fluids and pressures in the well borehole. When the snorkel is extended into the formation, this enables direct fluid communication from the formation into the tool. This permits taking of a sample, and it isolates the sample from invasion of pressure in the well borehole. This permits a sample to be taken free of contamination of other fluids, and it permits pressure tests to be made by means of a pressure sensor to thereby obtain an accurate readout of formation pressure without distorting the data.
It has been found desirable to run a pretest, a procedure known heretofore. A pretest is implemented after a sealing pad has isolated the formation from the well borehole fluids and the snorkle has penetrated into the formation of interest. In part, the pretest is used to determine whether or not the snorkle has been properly sealed with the surrounding sealing pad, and it is also used to measure the original or beginning pressure at the snorkel in the formation undergoing test. It is possible to obtain formation pressure drawdown and buildup during the pretest sequence which aids in measuring formation permeability. This enables preliminary data to be obtained which is very useful in evaluating the particular formation. Another use is to drawdown sufficient fluid to reduce or overcome formation invasion by drilling fluid.
The present apparatus is directed to a formation tester which has the capacity of obtaining both a pretest and post test sequence, typically formation pressure drawback and buildup sequences. The post test pressure drawdown permits evaluation of formation pressure recovery. Post test data is addition information significant in evaluating the formation.
An important procedure in execution of such test is to have the capacity of extending and retracting the snorkle on command. The snorkel is routinely constructed with a filter screen on the snorkle which may become clogged or plugged at any time in the operation. Retraction and extension after retraction of the snorkel is an important feature to enable the screen area on the snorkel to be wiped clear. When this can be done, this assures additional tests can thereafter be run without distorting the data as a result of clogging the screen on the snorkel.
With the foregoing in view, the present apparatus is described as an improved formation testing apparatus capable of execution of certain improved procedures. One of the enhancement methods of operation is the post test formation pressure drawdown and formation pressure buildup sequence wherein post test formation data can be obtained. Another important procedural advantage of the present invention is the ability to periodically retract and extend the snorkel to thereby wipe the screen on the snorkel clean to prevent clogging. More will be noted concerning these and other features of the disclosed apparatus and method of use hereinafter.
DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, 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 shows a formation pressure testing tool in accordance with the present disclosure suspended in a well borehole for conducting formation pressure testing;
FIG. 2 is hydraulic schematic of the formation tester of the present disclosure showing the circuit thereof;
FIG. 3 is a detailed view of the probe of formation tester in the extended position showing the screen thereof which may be blinded by clogging wherein retraction and extension wipe the snorkle screen clean;
FIG. 3A is a detailed view of snorkel construction; and
FIGS. 4 through 12 are similar hydraulic schematics showing certain lines pressurized to illustrate certain operational steps.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is directed to FIG. 1 of the drawings where a formation tester 10 is suspended in an open well borehole 12. The well is filled with drilling fluid commonly known as drilling mud indicated at 14. The formation tester is supported on an armored logging cable 16 which extends upwardly to a sheave 18. The cable 16 passes over the sheave and is stored on a drum 20. The armored logging cable 16 encloses several conductors which connect with a control system 22. The control system 22 also connects with a power supply 24 which furnishes power for operation of the formation tester 10 through the cable 16. Data obtained from the formation tester 10 is supplied through the cable 16 to a recorder system 26. The depth of the formation tester 10 in the well borehole is indicated for recording by electrical or mechanical depth measuring apparatus 28 connected to the sheave 18. It is input to the recorder 26 so that the data obtained is matched with the particular depth of the formation tester 10 in the well borehole 12.
Proceeding further in FIG. 1, the formation tester 10 supports a laterally extended probe 30. The probe is driven by a piston to extend from the tool body. It supports a surrounding ring 32 of elastomeric material. The soft material 32 forms a seal pad which seals against the side wall of the well at the formation 34. Assume that the formation tester 10 aligns with the formation 34 suspected to have formation fluids worth producing. The formation 34 is tested by extending a snorkel 36 into the formation. In operation, the snorkel 36 is isolated to enable it to respond only to fluids within the formation 34. This enables a true and accurate measure of formation pressure to be obtained. It is important to obtain such measurements isolated from drilling fluid intrusion. Normally, the drilling fluid forms a mud cake against the side wall of the drilled hole 12. This mud cake is desirable because it helps isolate the various formations penetrated by the well borehole. When the drilling mud packs against the side wall, there is a tendency for fluid in the drilling mud to penetrate into adjacent formations. The solid particles which make up the drilling mud form a filtrate cake against the formation wall. Liquid from the mud cake invades the adjacent formations. It is necessary for the snorkel 36 to then penetrate through the mud cake and sufficiently deep into the formation 34. As will be understood, the snorkel 36 is pushed through the mud cake and deep into the formation. This runs the risk of clogging an entry screen 38 (see FIG. 3). Retraction and extension of the snorkel 36 enables wiping the screen 38 to reduce screen clogging.
The probe is ordinarily extended in the manner shown in FIG. 3. To assure alignment and positioning, double acting backup pistons extend backup shoes 40 shown in FIG. 1. Ideally, there two backup shoes. They are vertically aligned along the tool body and are diametrically opposite the seal pad and snorkel. Preferably, one or more is located above the snorkel and a similar arrangement is made below the snorkel. This fixes the tool body at a particular location in the well borehole and assists in securing the tool body during formation testing operation.
Tool operation involves use of the snorkel 36 to fill various pressure vessels within the formation tester 10. The timed relationship of operation of the snorkel to fill the sample chambers in the formation tester 10 will be described in detail hereinafter. Some detail must be given to enhance he understanding of FIG. 3 which includes the hydraulic system generally indicated at 50.
FORMATION TESTER HYDRAULIC SYSTEM
In FIG. 2 of the drawings, the hydraulic system 50 is shown in detail. The components will be described first and the operation of this system will be set forth in detail later. A chamber 51 establishes a particular hydrostatic pressure level. The chamber is loaded from the exterior pressure above the pressure in the borehole. A motor 52 drives a pump 53 which delivers hydraulic fluid at some pressure greater than the pressure of the drilling fluid. It will be understood that the formation tester 10 is located at different depths in different weights of drilling mud and is therefor eexposed to a highly variable external pressure. The hydraulic system operates at a pressure which is equal to the external or mud pressure plus an increment sufficiently higher to assure operation. It connects with an outlet line 54 which delivers oil at an elevated pressure. A relief valve 55 dumps to sump in the event that pressure is excessive. A check valve 56 in the line 54 prevents back flow. Downstream of the check valve, another relief valve 57 is also incorporated. Additionally, this downstream location is connected with a pressure detector 58 which forms an indication of instantaneous pressure. A serial priority valve 59 is also included to isolate certain control valves in the event the hydraulic system is unable to sufficiently supply all of the control valves at once if there is a momentary high demand for hydraulic oil.
The hydraulic control system 50 incorporates several similar, or even identical control valves. They all have similar construction. They are identified by the letters A-F. Preferably, the valves A-F are all solenoid operated. In the deactivated position they all connect to sump. Connection of each solenoid valve to the sump in the deactivated position has two benefits, (1) to relieve pressure on a component when it is no longer being operated; and (2) to provide a fail-safe method of relieving hydraulic pressure on operated components in the event of power failure. This feature eliminates the need for an emergency dump valve, as used by other systems. When the solenoid is operated, a connected path through the respective control valves is then created.
Going now to additional components in FIG. 2, the backup shoes 40 are also shown spaced on both sides of the snorkel 36. The snorkel is able to receive formation fluid into the snorkel which is received in the formation tester 10 through the sample line 60. The sample line 60 runs from the snorkel 36 to other components as will be described. The sample line includes a branch which connects with the equalizing valve 61, a double acting valve. This valve includes an external port which opens to the exterior to the formation tester 10 to be exposed to drilling mud. The external mud is at a pressure represented by the symbol H, this pressure being introduced by the external port to equalize across the snorkel and seal pad 32 to avoid sticking of the formation tester 10. The equalizing valve 61 selectively opens the external port, to connect the port to the sample line 60.
The sample line 60 also connects with drawdown chambers 63 and 64. The drawdown chambers 63 and 64 have double acting pistons. The sample line 60 also connects to a pressure detector 65. The detector 65 measures the pressure in the sample line.
The sample line 60 additionally connects with first and second storage chamber valves 66 and 67. The two storage valves in turn connect with first and second storage chambers 68 and 69. They are sized to hold samples delivered through the sample line 60 of a specified volume.
In general terms, the apparatus for handling the samples actually obtained has now been described. However, the system 50 includes additional apparatus which should be identified. There are three additional valves identified by the numerals 71, 72 and 73. The system 50 includes check valves 75, 76, 77 and 78. For purposes of easy identification, selected hydraulic fluid lines need to be described. The numeral 80 identifies the setting line. That connects from the control valve B to the equalizing valve 61, the backup pistons 40, and the valve 71. The fluid line 85 is the retract line, and it connects to the equalizing valve 61, backup pistons 40, and control valve F. The numeral 90 identifies the extension line involved in operation of extending the snorkel.
Operation of the hydraulic system 50 shown in FIG. 2 is enhanced by review of additional drawings. The same structure 50 is shown in all these drawings. However, the supplemental views of the system 50 are highlighted to bring emphasis to the system 50 operation. The views following FIG. 4 can be considered in a sequence, but the sequence maybe varied for a number of reasons. The additional views show fluid flow routes during operation. Accordingly, going now to FIG. 4, hydraulic fluid under pressure is delivered through the setting line 80. This line has been graphically marked in a different fashion to bring this fact out. This sequence is accomplished by switching the control valve B to deliver oil under pressure to close the equalizing valve 61 and to set the backup shoes 40. Also, the pressure on the setting line 80 is delivered to the valve 71 to operate that valve. The setting line 80 powers the double acting pistons 40 to force oil into the retraction line 85. FIG. 4 shows the line 85 highlighted to illustrate this flow path. This oil is returned to sump through the vontrol valve F. When this operation is completed, the equalizing valve 61 has been closed and the pistons 40 have been extended. In FIG. 4, the lines 80 and 85 marked to show the high pressure fluid delivered through the line 80 and fluid returned through the retraction line 85.
FIG. 4 should be contrasted with FIG. 5 involved with extension of the snorkel. This is accomplished by the control valve D which delivers oil under pressure through the valve 73 into the extension line 90. As the snorkel is extended, hydraulic fluid is returned to the retraction line 85. The two particular flow paths specially marked in FIG. 5 should be contrasted with FIG. 4. To this point, the control valve sequence is first operation of the control valve B and subsequent overlapping operation of the control valve D. The valve operating sequence will be summarized in a chart.
In FIG. 6, the snorkel has been retracted. This is achieved by operation of the control valve F. This delivers fluid under pressure to retract the snorkel. This utilizes the retraction line 85 with part of that line isolated by the check valve 75. Return is through the extension line 90 to the valve 73 (partially blocked by the check valve 77) and return sump through the control valve D.
The operator may by application of suitable control signals extend and retract the snorkel many times to be sure that it is wiped clean. This can be done simply by repeating the sequence of operations shown for FIGS. 5 and 6. Again, both of these steps occur with the valve B sustained open, the equalizing valve 61 closed, the probe 30 extended, and the backup shoes 40 extended. FIG. 6 highlights the involved lines.
Going now to FIG. 7, the next step is to perform a pretest drawdown from the extended snorkel. In other words, the operation shown with FIG. 7 follows the operation of FIG. 5. Recall that the snorkel may be extended and retracted several times; this pretest sequence is undertaken with the snorkel extended, the position accomplished in FIG. 5.
FIG. 7 shows operation of the control valve C which delivers hydraulic fluid to the drawdown chamber 64 to initiate pretest drawdown. This sequence of operation is best related to the pressures experienced at the snorkel. When the snorkel is first extended into the formation undergoing test, the snorkel is exposed to pressure which is influenced by the drilling fluid in the well. It may also be influenced by the filtrate from the mudcake on the side wall. When the snorkel is extended into the adjacent formation, there maybe a compacting of sand in front of the snorkel which localizes a pressure increase. The snorkel is extended into the formation to observe formation pressure. The initial intrusion of the snorkel and the potential intrusion of mud filtrate are factors tending to provide initial short or long term misleading high reading. To overcome this possibility of an initial high reading, there is a formation pressure pretest drawdown and formation pressure buildup sequence. The pressure detector 65 reads the pressure observed in the sample line 60 from the snorkel. For elimination of the pretest pressure buildup, it is desirable that pressure in the sample line be momentarily reduced. This reduction may draw fluid through the snorkel into the sample line, thereby reducing the pressure disturbances arising from snorkel disturbance of the formation. This is accomplished by pulling a partial vacuum in the means 64. This chamber is filled by the rush of fluid coming through the sample line from the snorkel. After this occurs, fluid from the formation then flows into the snorkel and the pressure in the sample line can then increase. The pressure is observed at the detector 65 and data can be taken representative of formation pressure before testing. The data of pressure versus time implies fluid flow in the formation, or permeability.
Proceeding in sequence, the next step after a pretest drawdown is to fill the first sample chamber 68. This is accomplished by operation of the control valve E. As shown in FIG. 8, this control valve in conjunction with the valve 72 operates the chamber valve 66. When high pressure is applied to the chamber valve 66, a return route through the valve 71 opens into the retract line 85. That returns fluid to sump by the valve F. After some interval in which the chamber 68 is filled with sample drawn through the snorkel into the sample line 60, it is then necessary to end this sequence by closing the valve 66 to isolate the sample chamber 68. This operation is best understood by reversing that which is shown in FIG. 8. The sample chamber 68 is filled when high pressure is applied through the valve E while the valve F is used to return fluid to sump. The two valves are reversed so that the sequence of operations highlighted in FIG. 8 is then reversed as shown in FIG. 10, high pressure is delivered from the control valve F to close the chamber valve 66 while the control valve E returns to the original position, thereby defining return fluid path to sump. It is to be noted that control valve D is operated while filling the sample chamber 68 to insure that snorkel 36 remains in its extended position.
Attention is now directed to FIG. 9 of the drawings. Here, the sequence of operations opens the second sample chamber 69 to receive the second sample. This sequence involves opening both valves C and D simultaneously. The control valve C is operated to apply control pressure to the valve 73. When the control valve C operates, pressure to the means 64 and the valve 72 cause no change. The valve 73 enables high pressure fluid from the control valve D and the valve 73 to operate the chamber valve 67. The chamber valve 67 is operated, thereby enabling the sample chamber 69 to accumulate the second sample. This sample collection is carried on for a period of time until the chamber is sufficiently full. This operation is accompanied by a return of fluid from the chamber valve 67 along the common return path previously discussed with FIG. 8. In this regard, the chamber valves 66 and 67 are connected in common to this return path.
Attention is next directed to FIG. 10 of the drawings which shows joint closure of both of the sample chambers 68 and 69. To accomplish this, the control valve F is operated to apply high pressure fluid from the valve F through the valve 71. This route is through the retraction line 85. The high pressure closes the chamber valve 66 and 67. Return fluid from the chamber valves 66 and 67 flows through two separate routes. The chamber valve 66 return fluid passes through the check valve 76 and then to sump through the control valve E. The chamber valve 67 return fluid is through the check valve 77 and then to the control valve D and to sump.
Going now to FIG. 11, the next sequence of operation is shown. Before this step is described, it should be noted that the activities accomplished to this point include the pretest drawdown, filling of the first sample chamber 68 and/or filling of the second sample chamber 69. The sample chambers are isolated by closing off the chamber valves 66 and 67 described in conjunction with FIG. 10. At this time, the pressure in the sample line 60 should settle to formation pressure; if not, pressure in the line 60 will settle a few seconds after closing the chamber valves 66 and 67. A post-test drawdown sequence is then implemented. In this sequence, the means 63 is expanded. This expansion momentarily reduces pressure in the sample line 60. When this occurs, pressure is read at the pressure detector 65. Moreover, this permits additional formation fluid from the snorkel to flow into the sample line. This connects the sample line 60 with the formation to measure formation pressure. In FIG. 11 of the drawings, the post-test drawdown sequence is accomplished by the simultaneous opening of control valves C and E. The control valve C sets the valve 72 for operation, and high pressure fluid from the control valve E flows through the valve 72 and then to the post test drawdown means 63. This is operated for the necessary interval. The pressure information is obtained from the pressure detector 65. In turn, the means 63 delivers return fluid through the outlet line into the retraction line 85, then through the check valve 75 and along the line 85 to the control valve F and then to sump.
At this point, testing is over and the formation tester can be retrieved. However, after testing is over, the formation tester must be disengaged from the formation 34. This requires that the seal pad 32 and the snorkel be retracted. This is done by reversing the means 63 and 64, that is, reverse the pretest and post-test drawdown. Recall that the means 63 and 64 are chambers which expand, thereby filling with fluid from the sample line. FIG. 12 shows several events which occur in this sequence. It is important to note that the control valve B is closed and thereafter the control valve F is opened. During all the steps (FIG. 4-11) from initial landing of the formation tester 10 opposite the formation 34 to the situation prevailing at the end of FIG. 11 operation, the control valve B was open so that the backup pistons 40 were extended and the equalizing valve 61 was closed. Therefore, FIG. 12 shows the control valve B returned to the initial condition in which it is not operated.
The setting line 80 then becomes a return line for return fluid. This return will be described first. The equalizing valve 61 is opened and a return fluid path is made available for both of the backup pistons 40. Further, the line 80 permits the valve 71 to be reversed, this valve being held under control of the control valve B for the entire sequence of operation beginning with FIG. 4 and extending to FIG. 12. The valve 71 is then reversed. This also opens the sample line 60 to hydrostatic pressure in the well through the equalizing valve 61. This aids in unsticking at the seal pad and snorkel. Assume for purposes of illustration that the pressure in the well is 2000 psi while formation pressure is only 1000 psi. When the equalizing valve 61 is opened, well fluid is permitted to flow through the valve 61 into the sample line 60 and reduces the tendency for pressure differential sticking of the seal pad and snorkel. The seal pad has a greater tendency to stick than does the snorkel. The valve F is thereafter opened. This provides high pessure fluid through the valve F and to the retraction line 85. This retraction line connects with both of the drawdown means 63 and 64. The volumetric capacity of each is reduced, thereby forcing fluid backward through the sample line 60. This tends to increase the fluid delivered through the snorkel, reducing pressure differential sticking potential at the exposed seal pad and snorkel. Moreover, when the pressure from the control valve F is introduced into the line 85, it also is applied to the equalizing valve 61 to provide positive drive for opening. Thus, the double acting equalizing valve is properly powered and a returned fluid path is opened. The pressure in the sample line is thus simultaneously increased while the equalizing valve is opened; these two operations together assure delivery of fluid through the sample line 60 out through the snorkel to accomplish equalization at the snorkel into the formation.
Another facet of operation resulting from the control valve F is application of high pressure fluid to achieve retraction of the snorkel. Additionally, the retraction line 85 accomplishes retraction of the backup pistons 40. The backup pistons have a return flow path through the setting line 80. The snorkel is provided with a return fluid flow path through the extension line 90. This line connects through the valve 73 and then into the control valve D and to sump.
To summarize the sequence of operations, the chart below will assist in understanding the various sequences. The three columns are appropriately labeled as the control valve, operation or the event occurring, and the particular figures (referring to FIG. 4-12) which shows this operation.
______________________________________ FIG-CONTROL VALVE OPERATION URE______________________________________Open B Extend Backup Shoe 40 FIG. 4 Close Equalizer Valve 61Hold B Open Extend Snorkel 36 FIG. 5& Open DHold B Open, Retract Snorkel 36 FIG. 6Close D &Open FHold B Open, Pretest Drawdown at 63 FIG. 7Open CHold B Open, Fill Sample Chamber 68 FIG. 8Close C, Open E,Open DHold B Open, End Sample Filling FIG. 8Close E & Open FHold B Open, Fill Sample Chamber 69 FIG. 9Open C & Open DHold B Open, Close Both Sample Chambers FIG. 10Close C & Close D 68-69& Open FHold B Open, Post-test Drawdown 64 FIG. 11Close F &Open C & EClose C & E; Open Equalizer 61, FIG. 12Close B & Retract Snorkel 36,Open F Retract Backups 40, Reset Drawdowns 63 & 64______________________________________
As will be understood, the foregoing procedure is not the only sequence of operation. Through the appropriate operation of control valves A-F, other sequences of operation can be obtained. The control valves A-F are either operated independently, or programmed in the computer for a sequence of operation, or operations.
In use, the present apparatus particularly enables the execution of formation testing with the means 10 to obtain isolated pretest and post-test pressure in the measurements. The drawdown sequence is particularly helpful to remove fluid from the sample line and thereby remove any bias which may arise to obtaining formation pressure measurements. The measurements from the formations are ideally obtained free of bias. The bias, as mentioned before, may arise as a result of filtration from the mudcake of drilling fluids, and may also arise as a result of snorkel intrusion into the formation. It is helpful to have static formation measurements both before and after sample draw. For instance, if after a specified sample is obtained in the sample of chamber(s) in a measured interval, an additional post-sample formation drawdown and pressure buildup observation may be important to observe the duration of rate of formation pressure recovery plus additional formation properties such as an estimate of formation permeability through correlation of pressure/time curves, and deepest possible fluid contacts in part of the formation not penetrated by the borehole. This is indicative of lateral fluid flow (or permeability) in the formation. The second or post-test, formation pressure drawdown and formation pressure buildup versus time gives an additional indication of formation fliud flow, or permeability. This second formation drawdown and formation pressure buildup typically will provide different and more valuable data than formation pretest data since the second or post-test sequence involves more of connate formation fluids and is likely more valuable. An important facet is reduction of differential pressure sticking at the seal pad and snorkel. Recall that the snorkel is extended into the formation and may well be exposed to a significantly reduced pressure. If that is the case, differential sticking is reduced by reversing the flow from the drawdown means 63 and 64. By reversing the flow from the two separate means connected to the sample line, a larger feedback is obtained and thus, the sticking which might occur around the seal pad and snorkel is markedly reduced. As mentioned earlier, the snorkel can be reciprocated several times to wipe the screen of the snorkel clean and reduce the tendency to blind.
There are many other advantages, some perhaps arising from alternate modes of operation of the formation tester 10 of this disclosure. While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow. | A formation tester is set forth. The device utilizes a snorkel extending from the formation tester to obtain a pressure test and collect samples from a formation of interest. The apparatus includes multiple sample storage containers. The sample line is connected to storage containers and also to pretest and post-test drawdown elements which alter the sample line back pressure, thereby cooperating with an equalizing valve to selectively isolate the snorkel from fluid and fluid pressures in the well. | 4 |
This is a division of Ser. No. 09/330,228, filed Jun. 10, 1999 now U.S. Pat. No. 6,228,390, which is a continuation of Ser. No. 09/137,916, filed Aug. 20, 1998, abandoned, which is a continuation of Ser. No. 08/940,358, filed Sep. 30, 1997, abandoned, which is a continuation of Ser. No. 08/463,147, filed Jun. 5, 1995, abandoned, which is a division of Ser. No. 08/285,617, filed Aug. 3, 1994, now U.S. Pat. No. 5,480,717, which is a continuation of Ser. No. 07/990,722, filed Dec. 15, 1992, abandoned.
FIELD OF THE INVENTION
This invention relates to novel processes for adhering polymeric hydrogels to an adhesive coated surface of a substrate and to novel hydrogel laminates and bandages and methods for forming the same.
BACKGROUND OF THE INVENTION
The integumentary system is the exterior organ that, although often taken for granted, is vital to physical well being. The most obvious function of the integument is to protect against infection. Any alteration in the integrity of the skin compromises this natural defense. To minimize the risk of soft tissue infection, it is desirable to protect burns and wounds from infectious agents such as airborne fungi, bacteria and viruses. Traditional gauze type dressings are inadequate because they do not exclude infectious agents. Further, exudation from many types of skin lesions is normal during the healing process. If wound exudate has dried and consolidated the gauze dressing and wound, removal of the dressing is not only painful, it interferes with the healing process.
The use of hydrogels in the treatment and management of burns and wounds is well known in the art. Hydroqel dressings are desirable, in part, because they provide protection against infectious agents. Hydrogel dressings are further desirable because wound exudate does not generally dry and consolidate with hydrogels or hydrogel laminates. Consequently, removal of a hydrogel dressing is usually neither painful nor detrimental to the healing process. It has been suggested that hydrogel dressings may be particularly desirable for treatment of burns because they may accelerate healing. Although the mechanism by which hydrogels stimulate healing is not fully elucidated, it is documented that the high water content of hydrogels enables them to effect an immediate cooling of the wound surface and to sustain the reduced temperature for up to six hours. Davis, et al., “A New Hydrogel Dressing Accelerates Second-Degree Burn Wound Healing,” Poster Presentation, Wound Healing Society First Annual Meeting, Galveston, Tex., Feb. 6, 1991. In addition, water swollen hydrogels may provide a cushioning effect that helps protect the burn or wound from physical trauma.
U.S. Pat. No. 4,438,258 relates to hydrogels which may be used as interfaces between damaged skin tissue and its external environment. As disclosed therein, hydrogels may be polymerized about some type of support, such as a mesh of nylon, used as an unsupported film, spun in fibers and woven into a fabric, or used as a powder. Further, hydrogels may be used to provide a controlled release of a medical composition.
U.S. Pat. No. 4,552,138 discloses a wound dressing material of at least one layer of a polymeric, hydrophilic gel wherein the gel is cross-linked and acetalized with formaldehyde. As disclosed therein, a gel film may be formed by spreading a pre-crosslinked gel on an auxiliary carrier, drying and at the same time cross-linking the same by heat treatment. As used in this disclosure, un-crosslinked polyvinyl alcohol is dissolved in water, acidified, preferably by hydrochloric acid, and combined with an aqueous formaldehyde solution and left to react or pre-crosslink at 50-80° C. for several hours to obtain a gelatinous mass wherein no further free aldehyde can be detected. Such gel films may be placed on the wound as such, but they are preferably processed to a laminated product with one or more carrier materials and used in this form. The carrier layers are laminated into or onto the pre-crosslinked gel layer and may be further cross-linked to bond more firmly with the gel.
U.S. Pat. No. 4,554,317 discloses a synthetic hydrophilic membrane prepared by graft polymerization of hydrophilic monomers with a polyurethane substrate. This membrane is particularly useful as a wound covering material. In one embodiment of this invention, the graft polymerization is initiated by X-ray or gamma radiation or an initiator such as a cerium salt.
EPO Publication No. 0 107 376 A1 discloses a tacky, non-rigid transparent and absorbent dressing comprising a layer of cross-linked polyvinylpyrrolidone gel containing from about 75-85% water. The dressing may be prepared by dissolving between 15% and 25% by weight of polyvinylpyrrolidone in water and cross-linking the polyvinylpyrrolidone by means of ionizing radiation.
U.S. Pat. No. 4,567,006 discloses a moisture vapor permeable, adhesive surgical dressing comprising a continuous film of a hydrophilic polymer. Such a dressing is suitable for use on moist wounds because it allows water to evaporate rapidly from the wound area in the presence of an excess of exudate but, as the amount of exudate diminishes, so does the rate of evaporation. The resulting amount of exudate is enough to keep the wound moist without causing blistering of the dressing.
U.S. Pat. No. 4,798,201 discloses a surgical dressing consisting essentially of a film which carries an adhesive layer for securing the dressing to the body. This dressing is also suitable for use on exuding wounds.
U.S. Pat. No. 4,407,846 discloses a method of producing a hydrophilic membrane from a polyethylene base film by first irradiating the film of thickness not more than 150 μm with ionizing radiation in air or an oxygen atmosphere. Then, without additional radiation, acrylic acid and/or methacrylic acid present in the form of an aqueous solution is grafted onto the irradiated film.
U.S. Pat. No. 3,669,103 discloses a flexible support adapted to be caused to conform to a surface of a body, wherein the support confines a dry, solid, water-swellable, water-insoluble polymeric sorbent to absorb aqueous fluid elaborated by the body to which the support is applied. The polymer sorbent is a lightly cross-linked polymer.
U.S. Pat. No. 4,192,727 discloses a polyelectrolyte hydrogel and method for preparing the same. The polyelectrolyte hydrogel is formed by exposing an acrylate salt and acrylamide to a controlled intensity and dose of ionizing radiation to effect simultaneous cross-linking and polymerization thereof. The resulting hydrogel is an insoluble hydrophilic copolymer which can contain or absorb aqueous fluid.
U.S. Pat. No. 4,646,730 discloses a color stabilized sulfadiazine hydrogel dressing comprising a non-rigid layer of cross-linked polyvinylpyrrolidone gel having incorporated therein at least 0.1% by weight of silver sulfadiazine, which gel has been exposed to electron beam radiation and which gel also contains a color stabilizing amount of magnesium trisilicate.
U.S. Pat. No. 4,750,482 discloses a wound or burn dressing comprising a web-like substrate coated with a layer of crosslinked, water-insoluble, hydrophilic, elastomeric, pressure-sensitive adhesive gel of a gel-forming, water-soluble polymer derived from repeating units, predominantly of vinylpyrrolidone, polyethylene glycol wherein the cross-linked gel is formed by radiation cross-linking of a solution or dispersion of the polymer in the plasticizer and water. The gel retains the plasticizer within a cross-linked three-dimensional matrix of the polymer.
EPO Publication number 0 304 536 A2 discloses an occlusive wound dressing comprising an adhesive layer, a fabric layer bonded to the adhesive layer, a hydrophilic absorbent polymeric layer applied to the fabric layer, and at least one occlusive backing layer. The hydrophilic absorbent polymeric layer of this dressing is applied by pouring a monomer solution onto the fabric layer and thereafter curing to yield the polymeric layer.
Japanese Patent Application No. 57-7414 issued in the name of Saburo Otsuka and assigned to Nitto Electric Ind. KK, discloses a medicinal plaster formed by spraying or spreading a solution or dispersion containing a monomer, a medicine, a releasing aid for medicine, etc., on the surface of a tacky layer formed on a support, and then irradiating it with UV or ionizing radiation.
U.S. Pat. No. 4,871,490 discloses a method of manufacturing hydrogel dressing from synthetic and natural polymers by radiation cross-linking. The method involves an aqueous solution comprising 2-10% by weight polyvinylpyrrolidone, no more than 3% by weight of agar and 1-3% by weight of polyethylene glycol. The solution is poured into a mould to shape the dressing. The mould is then tightly closed and subjected to an ionizing radiation dose in the range of 25-40 KGy.
At present, there are a few commercially available hydrogel dressings, for example, Second Skin from Spenco and Vigilon from C. R. Bard. However, a significant problem with hydrogel dressings is that the high water content of the hydrogel makes a good adhesion with a substrate problematic. Failure to establish an adequate bond between the hydrogel and the substrate may lead to delamination and failure of the product. Consequently, currently available hydrogel dressings utilize a secondary dressing to keep the hydrogel in place. This is both inefficient and costly. It also makes the product hard to use on certain body areas. Accordingly, there is a need for adhesive bandages having a hydrogel pad securely adhered to a substrate and for processes by which a polymeric hydrogel can be securely adhered to a substrate.
It is an object of this invention to provide hydrogel laminates with improved delamination resistance and processes by which a polymeric hydrogel can be securely adhered to an adhesive coated surface of a substrate. It is a further object of this invention to develop improved adhesive bandages having absorbent hydrogel pads.
SUMMARY OF THE INVENTION
These objects have been met with the present invention. This invention relates to a hydrogel laminate comprising a substrate, such as a moisture impermeable film, a layer of polymeric adhesive on at least one surface of said substrate, and, adjacent to said adhesive coating, a layer of hydrogel. The hydrogel is formed by crosslinking of one or more hydrophilic polymers. The hydrophilic polymer(s) which form the hydrogel and the base polymer(s) of the adhesive are selected so that the these polymers are capable of copolymerizing with one another, for example, upon exposure to ionizing irradiation. The laminate so formed may be used as a component in a bandage for wound dressing, and, because of the excellent delamination strength of the laminate, such bandages offer advantages over hydrogel dressings previously known.
This invention also relate to a process for forming a hydrogel laminate. In this process, a substrate is coated on at least one surface with one or more polymeric adhesives. An aqueous solution of one or more hydrophilic polymers is cast onto the coated surface of the substrate, and the resulting composite is exposed to ionizing irradiation suitable to cross-link the hydrophilic polymers to form a hydrogel and to copolymerize the base polymers of the hydrogel and of the polymeric adhesive.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a laminate 10 comprising a substrate 16 , an adhesive 18 , and a hydrogel 20 .
FIG. 2 is a cross sectional view of the hydrogel illustrated in FIG. 3 taken along line 1 — 1 .
FIG. 3 is a perspective view of a bandage utilizing a hydrogel laminate of this invention.
FIG. 4 is a cross sectional view of a laminate containing a reinforcing layer disposed within the hydrogel.
FIG. 5 is a cross sectional view of the laminate of FIG. 4 during pressing in a mold.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to the preparation of hydrogel laminates, useful in absorbent products such as bandages. Hydrogels are three-dimensional networks of hydrophilic polymers, generally covalently or ionically cross-linked, which interact with aqueous solutions by swelling to some equilibrium value. These cross-linked gels are generally formed from synthetic polymers (such as polyvinylpyrrolidone, polyethyleneoxide, acrylate and methacrylate polymers and copolymers), multivalent alcohols (such as polyvinylalcohol), biopolymers (such as gelatin, agar), or combinations thereof. For the purpose of preparing bandages or wound dressings, as in this invention, additional agents may be incorporated into the hydrogel, such as, but not limited to, color stabilizers or coloring agents, and medicaments such as antibacterial agents.
A preferred hydrogel for use in this invention is crosslinked polyvinyl pyrrolidone (PVP). Best results have been achieved using PVP polymers having a viscosity average molecular weight of about 150,000-450,000 and preferably about 200,000-300,000. An especially preferred PVP polymer is PVP K-60, available from GAF Corporation, Wayne, N.J., having a viscosity average molecular weight of about 220,000. The viscosity average molecular weight was derived by the method described by W. Scholtan, Makromol Chem., 7, 209 (1951) and J. Hengstenberg et al. Makromol Chem., 7, 236 (1951). The hydrogel preferably comprises about 30 to 60, preferably about 40 to 50, weight % of the polymer complemented by about 40 to 70, preferably 50 to 60, weight % water. If the molecular weight of the PVP is too high, e.g. 700,000, it is not possible to make a solution with a high enough PVP concentration, and the resulting adhesion to the polymeric adhesive layer after irradiation is not acceptable. If the molecular weight of the PVP is too low, e.g., 40,000, the PVP chains are too short to entangle with and polymerize with the polymeric adhesive layer.
The hydrogel laminate according to this invention includes a base substrate onto which the polymeric adhesive and hydrogel layer are placed. Suitable substrates include woven or nonwoven fabrics, plastic films, and laminates of woven or nonwoven fabrics and plastic films. It is generally preferred that the substrate include a moisture-impermeable thermoplastic film, examples of such films including copolyester ether elastomers, such as those sold under the tradename HYTREL by the DuPont Company, Wilmington, Del.
Polymeric adhesive is coated onto at least one surface of the substrate. As previously mentioned, the base polymer of the adhesive is selected so that it is copolymerizable with a polymer in the hydrogel, i.e., so that there are moieties on the adhesive polymer capable of covalently bonding with moieties on the hydrophilic polymer. It is also preferred that the adhesive polymer be a medical grade, pressure-sensitive adhesive which can be used to adhere the substrate to a patient's body. As an example, when the hydrogel is formed from PVP, it has been found that adhesives based on vinyl acetate, acrylic acid, acrylates or mixtures thereof are suitable since these are capable of copolymerizing with the PVP. Excellent results have been achieved using a copolymer of vinyl acetate, acrylic acid and 2-ethyl hexyl acrylate. A preferred adhesive for use with PVP hydrogel is GELVA® 2478, available from Monsanto Co., St. Louis, Mo., which is an acrylic multipolymer emulsion containing 2-propenoic acid polymer with ethenyl acetate, 2-ethylhexyl 2-propenoate and methyl 2-propenoate; water; and ethanesulfonic acid, 2-2-2 (octylphenoxy)ethoxy-ethoxy, sodium salt.
An aqueous solution of the hydrophilic polymer(s) which will crosslink to form the hydrogel is placed, or cast, onto the adhesive-coated surface of the substrate. The amount of water and polymer in the aqueous solution will be that required to produce a hydrogel of the desired water/polymer content. The composite formed by coating the polymer solution onto the adhesive-coated substrate is exposed to ionizing irradiation in a dose suitable to cross-link the hydrophilic polymer(s) to form the hydrogel and to copolymerize those hydrophilic polymer(s) and the adhesive polymer(s). Electron beam irradiation is the preferred type of ionizing irradiation. The suitable dose will, of course, depend upon the nature of the hydrophilic polymer(s) and of the adhesive polymer(s), and can be determined by one skilled in the art. Tests suggest that the electron beam irradiation dose should preferably be at least about 2.0 Mrads and no more than about 4.0 Mrads. In a preferred embodiment, the electron beam irradiation is applied in two doses. Dose rates of about 2.0 and 2.5 Mrads, 2.5 and 2.5 Mrads, 3.0 and 2.5 Mrads and 3.5 and 2.5 Mrads have been shown to directly adhere the hydrophilic polymer to the substrate, whereas adhesion was not achieved with a single dose of 4.5, 5.0, 5.5 or 6.0 Mrads. The time between each dose is not critical.
Irradiating the hydrogel laminate in two doses also provides a manufacturing benefit. After the first dose of ionizing irradiation, the hydrogen layer is partially cross-linked and has sufficient strength to be die cut into the desired shape and size. These die cut laminates may be processed into bandages using conventional techniques and then packaged in hermetically sealed containers, such as foil packs. The sealed containers are then subjected to the second dose of irradiation, which fully cross-links the hydrogel and sterilizes the product.
It is believed that the delamination resistance of the hydrogel laminates provided by this invention depends on the ability of the hydrophilic polymers of the gel and the polymers of the adhesive to copolymerize with each other to make strong covalent bonds.
Various reinforcing materials may be incorporated into the hydrogel layer for the purpose of strengthening the laminate. These materials are preferably porous or mesh-like layers about which the hydrogel polymerizes. Upon exposure to ionizing radiation, the reinforcing material is tightly bound to the hydrogel layer. The reinforcing layer is generally embedded within the hydrogel layer prior to exposure to ionizing radiation. Suitable reinforcing materials include mesh, scrims and reticulated or non-woven layers, such as nylon gauze, rayon mesh, DELNET film, available from Hercules, Inc., Wilmington, Del., and fusible fiber fabric containing polyethylene, polypropylene, polyesters and mixtures thereof.
Laminates of this invention are illustrated in FIG. 1 . The hydrogel laminate 10 comprises a thin substrate 16 , coated on one surface with an adhesive 18 , and a hydrogel 20 . The hydrogel 20 is crosslinked and covalently bonded to the adhesive 18 by electron beam irradiation.
The hydrogel laminates descried herein may be used to form bandages. The bandages may have various configurations including, for example, an island pad configuration or strip bandage configuration. In such configurations, the substrate, preferably a thermoplastic film coated on one surface with adhesive, generally extends beyond the hydrogel laminate in at least two opposing directions. Accordingly, the laminate is sized to be dimensionally smaller in length and/or width than the thermoplastic film to which it is adhered.
Referring to FIGS. 2 and 3, a hydrogel bandage 24 broadly comprises a thin, polymeric film 26 , coated on one surface with an adhesive 28 , and a hydrogel layer or pad 30 . The hydrogel 30 is crosslinked and covalently bonded to the adhesive 28 by electron beam irradiation. Adhesive 28 is preferably a medical grade, pressure-sensitive adhesive. The thin polymeric film 26 may be an embossed thermoplastic film. Suitable embossing patterns and methods for embossing thin polymeric films are known in the art and disclosed, for example, in U.S. Pat. Nos. 3,484,835, 4,298,647 and 4,376,147, incorporated herein by reference. In the illustrated bandage configuration, the hydrogel layer 30 may be in the form of an island pad, i.e., it would not be as long as either the thermoplastic film 26 or the adhesive layer 28 . Portions of the adhesive layer 28 are exposed and would be used to secure the bandage 24 to the body in the same fashion as a conventional adhesive bandage. The exposed adhesive portions may be covered by release papers which may be provided with central tabs to facilitate their removal. The dressing is packaged and sterilized prior to use.
Laminates of this invention containing the reinforcing layer are illustrated in FIG. 4 . The hydrogel laminate 40 contains a substrate 46 , coated on one surface with an adhesive 48 , and a hydrogel 50 . Embedded with the hydrogel 50 is a reinforcing layer 52 , such as a scrim. A polymeric release layer 54 , such as polyethylene, is provided over the exposed surface of the hydrogel 50 . The release layer 54 is peeled from the top of the laminate before use. The hydrogel laminate 40 may also be used to form bandages.
The mold illustrated in FIG. 5 is used to embed the reinforcing layer into the hydrogel 50 . The mold consists of a bottom plate 60 having a cavity 62 and a top plate 64 . The substrate 46 , containing the adhesive layer 48 , is placed in the bottom of the cavity. The hydrogel 50 is spread over the adhesive layer 48 and then covered with the reinforcing layer 52 , such as a nylon mesh. The release layer 54 is applied over the reinforcing layer 52 before pressure is applied to the laminate by the top plate 64 . As this pressure is applied, the reinforcing layer is forced into the hydrogel 50 and becomes embedded. This pressure also causes the hydrogel 50 to spread uniformly across the adhesive layer 48 . The laminate is removed from the mold and then irradiated.
EXAMPLE I
A 2 mil thick copolyester ether elastomer substrate (HYTREL® 4778) was coated on one side with an acrylic multipolymer emulsion adhesive (GELVA® 2478) at 1.2 ounces per square yard (oz/yd 2 ). The adhesive coated substrate was placed in a cavity of a two piece metal mold (14 in.×14 in.) having the construction shown in FIG. 5 . The cavity in the bottom plate was also square (10 in.×10 in.) and had a depth of 60 mil. The adhesive coated side of the substrate faced upward.
The hydrogel layer was prepared by spreading sixty grams of a 45% (by weight) solution of polyvinyl pyrrolidone having a viscosity average molecular weight of about 220,000 (PVP K-60 from GAF) over the adhesive coated side of the substrate. The PVP solution was preserved with ascorbic acid by the manufacturer.
A reinforcing layer (fusible fiber fabric containing polyethylene and polypropylene) was placed over the hydrogel. A 7 mil thick polyethylene release film was placed over the reinforcing layer.
The top plate of the mold was placed over the bottom plate for a few minutes to allow the reinforcing layer to become embedded in the hydrogel. The resulting structure was then removed from the mold.
The structure was then irradiated using a two pass election beam irradiation process. The first pass was at 2.0 Mrads while the second pass was at 2.5 Mrads.
After irradiation the adhesion between the hydrogel and the substrate was examined. Very strong adhesion was observed, and the hydrogel layer would not readily peel (by hand) from the substrate.
EXAMPLE II
Example I was repeated except that a 20% (by weight) solution of polyvinyl pyrrolidone having a viscosity average molecular weight of about 700,000 (PVP K-90 from GAF) was substituted for the PVP used in Example I.
After irradiation, the adhesion between the hydrogel and the substrate was examined. The hydrogel layer readily peeled (by hand) from the substrate.
Variations and modifications of the aforementioned bandage can, of course, be made without departing from the spirit and scope of the invention as disclosed herein, and those skilled in the art will recognize multiple utilizations of the present invention that are within the scope of this disclosure. | The present invention provides processes by which a polymeric hydrogel can be securely adhered to a substrate to form a hydrogel laminate with greatly improved delamination resistance. The laminate is formed by casting onto a polymeric adhesive-coated substrate an aqueous solution of hydrophilic polymer, then exposing this composite to ionizing radiation which cross-links the hydrophilic polymer to form a hydrogel and also induces copolymerization of the hydrophilic polymer and the adhesive polymer. | 8 |
This application is a Continuation-In-Part application of International Application No. PCT/EP97/01465, filed on Mar. 22, 1997 which claims priority from Fed. Rep. of Germany Patent Application No. 196 11478.0, filed on Mar. 23, 1996. International Application No. PCT/EP97/01465 was pending as of the filing date of the present U.S. application and the U.S. was an elected state in the International Application No. PCT/EP97/01465.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a process and an apparatus for vault-structuring, in which curved material sheets are pressurized using supporting elements spaced at certain distances from each other.
2. Background Art
Numerous processes for profiling thin material sheets are known, including well-known deformation technologies such as rolling-in or embossing of beads with the aid of complicated form tools to create three-dimensional stiffening. The drawback of these mechanical deformation processes is that sophisticated and expensive form tools are required, that the material sheets to be profiled are heavily plastified, and that the surface quality of the raw material is degraded by the mechanical surface pressure.
The European patent application 0 441 618 A 1 describes a profiling technique in which polyhedral structures are produced with the aid of two embossing rolls. An apparatus is known for embossing axial beads into cans by supporting the can by axial, rigid elements on the inside and applying pressure from the outside by means of an elastic press roller (DE 35 87 768 T 2). U.S. Pat. No. 4,576,669 suggests feeding plastic foil over a roll that carries small cups into which the plastic foil is sucked by vacuum pressure. This process, however, does not enhance the inherent stability of the material. A process in which round, dome shaped structures are impressed in a foil does likewise not considerably improve the inherent stability of the material because large regions remain undeformed between the dents (French patent application no. 1,283,530).
Furthermore, a process is known in which thin material sheets or foils are profiled dent-like. In the process, the curved thin material sheet or foil is supported by line-shaped supporting elements on the inside and hydraulically pressurized from the outside. Offset quadrangular dent structures result that considerably improve the inherent stability of the material sheet (Deutsche Offenlegungsschrift 25 57 215 [=Patent Application Open To Public Inspection], German printed patent specification DE 43 11 978). In principle, this dent-profiling process differs from the one described in patent application no. 0 441 618 A 1 in that not two mechanically acting embossing rollers are required but only a supporting core on which the material sheet rests and against which it is hydraulically pressed. The hydraulic production of polyhedral structures, e.g. hexagonal profiles, has been described in the International Patent Application published as PCT/EP 94/01043, FIGS. 5 b and 5 c ). Instead of hydraulic pressure, an unprofiled, elastic cushion or an unprofiled elastomer can be used for pressurization. The supporting elements against which the material sheet is pressed are made of a flexible material which is either fixed or can move on the core.
The purely mechanical forming process described in the European printed patent specification no. 0 441 618 A 1 considerably affects the surface quality of the raw material by great mechanical deformation. The apparatus for producing axial beads described in DE 35 87 768 T 2 uses line-shaped, axial, rigid supporting elements and an elastic pressure element. However, the inherent stability of the material furnished with axial beads in this way is insufficient because, for geometrical reasons, beads do not yield multi-dimensional inherent stability. In contrast to beads the forming techniques described in O.S. 25 57 215, DE 43 11 978, and PCT/EP 94/01043 produce multi-dimensional inherent stability by creating offset vault structures without degrading the surface quality.
One of the problems of the known vault-structuring techniques is that, where the vaults in the profiled material are deep, local stretching and elongation occur, which can be so severe that considerable plastic deformation results, weakening the material so that it may tear.
Another problem of the known vault-structuring techniques for thin material sheets or foils is that the self-organizing of the folds that bring about the improvement of the inherent stability is not, or only insufficiently, made possible in some applications. Self-organization of the vault folds means a process in which the material is folded in several dimensions in a such way that its inherent stability is enhanced. For example, such vault-structuring is effected by the curved, thin material, which is supported on the inside by supporting collars spaced at certain distances from each other or a helical, rigid supporting spiral (O.S. 25 57 215), becoming instable due to external pressure. The instability triggers multi-dimensional folding of the material and offset, quadrangular vault structures are created. Thus the thin material is transferred into a new state, the most important characteristic feature of which is its improved inherent stability. One problem of these quadrangular vault structures is that severe plastic deformation may occur in the region of the vault folds which weaken the material. If, instead of rigid ones, flexible supporting elements (e.g. of rubber) are used which are allowed to move on a core in axial direction during the vault-structuring process, hexagonal vault structures are created. Such hexagonal vaults can also be produced by hexagonal, rigid supporting elements (PCT/EP 94/01043). Studies have shown that severe plastic deformation weakening the material may occur in the area of the hexagonal vault structures as well, similar as in the case of the offset, quadrangular vault structures. In addition, the material sheets thus profiled with quadrangular or hexagonal vault structures is difficult to flatten from the cylindrical into a flat shape without substantial loss of isotropic inherent stability. Studies have shown that the lateral vault folds arranged in the direction of feed of the material sheet can be bent into a flat shape only by application of considerable force. Because in this flattening process the vault folds perpendicular to the direction of feed of the material sheet are leveled and arched somewhat, the vault folds lose a portion of their initial inherent stability. The thicker the material sheets the more serious the problem, and no isotropic inherent stability of the profiled material sheets can be achieved in this way. Therefore, the known profiling techniques are limited to angular structures such as quadrangular and hexagonal profiles. Due to this limitation, the structure of the vault folds could not yet be optimized. Such optimization includes the geometry of the structure as well as the geometrical shape of the fold itself. The structure of the vaults, such as their size and depth, determines the increase in inherent stability at a given thickness of the material. The contours of the folds must adopt such a shape that despite their being smoothed only a minimum of plastic deformation occurs.
SUMMARY OF THE INVENTION
The solution of the task according to the invention is that the optimal shape of the vault folds is found out by presetting merely the macroscopic vault structure by means of supporting elements when profiling the material sheets by means of hydraulic or elastic pressure. The supporting elements subside in the course of the structuring, the structural folds themselves take over the function of the supporting elements, and the vault folds and troughs assume the optimal shape in such a way that they withstand the prevailing forming pressure with a minimum of plastification.
An embodiment of the process is that a curved thin material sheet or foil is supported on the inside by a flexible, helical supporting spiral and pressurized from the outside. The flexible supporting spiral slightly subsides to the external pressure, twisting in the process, so that the diameter of the supporting spiral slightly decreases. In this way first vault folds of roughly quadrangular shape form, which then self-adjust to an optimized shape. In the process the initially little developed vault folds of roughly quadrangular shape gradually take over the supporting effect of the supporting spiral, because the vault folds more and more support each other as the depth of the vault folds increases. On the other hand, the supporting effect of the supporting spiral gradually decreases as it yields more and more to the increasing pressure from outside of the material sheet. In this way the vault folds form themselves quasi automatically and, in a self-organizing process, assume the optimal shape that withstands the deformation pressure. This not only holds for the optimized geometrical arrangement of the vault structure but likewise for the shape of the individual vault folds, i.e. their outer contour or curvature.
The geometrical arrangements of the vault folds optimized through this process are, for example, structures shaped like a pointed spade with S-shaped flanks that arose from parallelograms the narrow sides of which are tapered and the long sides of which are rounded. The tapering vault folds are created in an optimized way by the fact that the self-organizing of the vault-structuring of a curved material sheet, which is supported on the inside by means of a helical supporting spiral, favors shortened vault folds parallel to the rotational axis of the supporting spiral, i.e. perdendicular to the direction of feed of the material sheet. The optimization of the shape of the individual vault folds in the direction of feed is demonstrated by the fact that only rounded (e.g. S-shaped) vault folds are created in that direction, i.e. vault kinks with a high degree of plastic deformation do not occur. In the regions of the material sheet where the vault folds meet, flattened folding saddles with smooth bending radii form. Thus multi-axis bending folds that would cause severe plastifications of the material are avoided.
Because the vault folds in the direction of feed of the material sheet are rounded and therefore can easily be deformed, they can be bent to a flat shape with little expenditure of force and a minimum of plastification. Additionally, the vault folds parallel to the rotational axis of the supporting spiral, i.e. perpendicular to the direction of feed of the material sheet, are shortened. The result is easy flattening of the material sheets structured in this way, while the isotropic inherent stability of the profiled material sheet is preserved. The result is a high degree of inherent stability of the material sheet at a minimum of plastic deformation. Therefore, thicker material sheets can be structured and flattened in this way.
However, the spade-shaped vault structures thus produced are not precisely uniform. The reasons for this are inevitable non-homogeneity and wall thickness tolerances of the material to be processed as well as uneven pressurization of the material sheet. Therefore, another embodiment of the process according to the invention is that the best possible conditions for the optimal forming of the vault structure are created. To achieve this, first the optimal folding is determined under self-organizing conditions, and then the supporting elements are designed thus that the vault structures evolving, in particular the contours of the folds, to a large extent correspond with the geometry as formed through self-organization.
The characteristic feature of the supporting elements optimized in this way is that the lateral supporting elements are rounded (e.g. S-shaped) and that the supporting elements result in a flattened or just slightly curved contour in the region where several supporting elements converge. The radii of the individual rounded (e.g. S-shaped) lateral supporting elements are not fixed. The result is a wide variation range of roughly spade-shaped vault structures with a high inherent stability and low plastic deformation of the raw material. The shortened vault folds perpendicular to the direction of feed of the material sheet are to be just slightly plastified as well, and therefore the supporting elements receive rounded contours.
The geometrical dimensions of the optimized supporting elements can be calculated by approximation with the aid of equation (1). Equation (1) was developed by trial for the self-organization of roughly quadrangular vault structures (O.S. 25 57 215) and it can also be used for roughly spade-shaped vault structures. n = 2.45 * D 0.5 h 0.333 * s 0.2 ( 1 )
where
n=number of vault structures in the direction of feed of the material sheet referred to one turning cycle of the supporting elements
D=diameter in mm of the supporting elements
h=mean distance in mm of the lateral supporting elements from each other
s=thickness in mm of the material sheets
With the geometric relation (2) for the vault number n on the circumference of the supporting elements n = D * π b ( 2 )
relation (3) results for the dimensions of roughly square vault structures (h=b):
h=b= 1.45 *D 0.75 *s 0.3 (3)
This equation valid for roughly square vault structures can by approximation be applied to roughly spade-shaped vault structures as well, with the mean distance in mm of the lateral supporting elements chosen for h. Because equation (3) is just an approximation for roughly spade-shaped vault structures, the conditions of equation (3) can to some extent be altered.
From equations (1), (2), and (3) it follows, for example, that the greater the wall thickness s of the material sheet to be profiled, the greater the distance h between the supporting elements will be, and the greater the diameter D of the supporting elements has to be chosen. Therefore, material sheets of greater wall thickness s receive larger vault structures than thin material sheets.
The process according to the invention guarantees high inherent stability of profiled material sheets and a small degree of plastic deformation of the material. The plastification reserves still in the material sheet can be used for secondary forming processes. Another embodiment of the process according to the invention is the use of the remaining plastification reserves of the profiled material sheet to improve the inherent stability even further. In the process according to the invention this is achieved, for example, by initiating the vault-structuring process described above by means of an elastic or hydraulic cushion, which is pressed against the material sheet and the supporting elements, and then pressing the cushion against the material sheets with increased pressure, so that the material is re-elongated in the region of the vault troughs. At the same time the friction between material sheet and supporting elements stops or restricts the movement of the material sheet in the direction of the vault trough, so that the material does not tear in the area of the supporting elements. The frictional effect is obtained by geometrical adjustment of an involute to the supporting elements in direction of the vault trough. The geometrical design of the contour of the supporting elements takes into account the minimum bending radii, which depend, among other things, from the wall thickness and the material properties of the material sheet to be profiled.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clause are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantageous design features as a result of the invention are described below. Various embodiments of the invention are described in the attached drawings and described in more detail.
FIG. 1 : schematic design of a device for producing vault-structured material sheets and/or foils by means of a flexible pressure roller and a roller on which supporting elements are arranged (radial section).
FIGS. 2 A and 2 B: aspect of two vault structures produced by means of a device equipped with an elastic, single-thread, helical supporting spiral.
FIG. 3 : aspect of a vault structure produced by means of a device equipped with an elastic, multi-thread, helical supporting spiral.
FIG. 4 : aspect of a vault structure produced by means of a device equipped with spade-shaped, rigid supporting elements.
FIGS. 5A, 5 B, 5 C, 5 D and 5 E: schematic design of supporting elements for producing spade-shaped vault-structured material sheets: aspect of supporting elements and four cross sections of supporting elements.
FIGS. 6 A and 6 B: schematic design of rigid supporting elements for producing spade-shaped vault-structured material sheets with re-elongation of the material.
FIGS. 7 A and 7 B: exemplary schematic design of a device for application of the process according to the invention, with a roller with supporting elements and a flexible pressure roller, for producing spade-shaped vault-structured cans.
FIG. 8 : exemplary schematic design of a device for application of the process according to the invention, with a roller with supporting elements and a concave flexible pressure cushion, for producing vault-structured cans.
FIG. 9 : side view of a spade-shaped vault-structured can.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts the basic structure of a device for application of the process according to the invention for producing vault-structured material sheets or foils. The material sheet 1 is bend around roller 2 , on which supporting elements 3 are arranged, and pressurized by means of the elastic pressure roller 4 to create the vault structures of the material sheet.
FIGS. 2A, 2 B and 3 show the aspect of unrolled vault-structured material sheets:
In FIGS. 2A, 2 B and 3 structures are shown that result if the vault folds adjust by self-organizing. This happens, for example, if a flexible helical spiral that gives way in the direction of the pressure is used as supporting element instead of a rigid helical spiral. In this case spade-shaped structures with tapered vault folds are created perpendicular to the direction of feed of the material sheet, and lateral, roughly S-shaped, vault folds in the direction of feed. The direction of feed in FIGS. 2A and 2B is along the long side of the sheet of paper. In FIGS. 2A and 2B a single-thread, helical supporting spiral was used. FIGS. 2A and 2B show two spade-shaped structures that differ in the shape of their lateral and tapered vault folds. The lateral vault folds are at the mean distance h from each other, while the vault folds perpendicular to the direction of feed of the material sheet are at the mean distance b from each other. In FIG. 3 a multi-thread helical supporting spiral was used. In this way different angles between the arrangement of the vault structures and the direction of the material sheet can be adjusted, because due to the directional dependence of the inherent stability it can be to advantage to produce the vault structures not by means of supporting elements arranged in the direction of or perpendicular to the direction of feed, but at an adjustable angle to it.
FIG. 4 shows an aspect of a vault structure produced by means of a device equipped with spade-shaped, rigid supporting elements. The shape and the contour of these rigid supporting elements correspond to a large extent with the spade-shaped vault folds that arise from self-organization. Because the radii of the individual rounded (e.g. S-shaped) supporting elements are not fixed, the variation range for roughly spade-shaped vault structures is wide.
FIGS. 5A, 5 B, 5 C, 5 D and 5 E explain the schematic design of rigid supporting elements for producing spade-shaped vault-structured material sheets by showing an aspect and four cross sections. In the aspect the regions of the supporting elements for which the contours of the supporting elements are depicted in cross sections are indicated by broken lines. Marking 1 . . . 1 is the cross section of a supporting element in the area of the lateral, roughly S-shaped vault fold. The design of the rounded contour of the supporting element has to take into consideration the minimum bending radius of the material sheet to be profiled. Marking 2 . . . 2 is the cross section of a supporting element in the area of the vault fold perpendicular to the direction of feed of the material sheet. The contour of this supporting element is likewise rounded. Markings 3 . . . 3 and 4 . . . 4 are exemplary cross sections of a rounded saddle of several converging supporting elements. Although the supporting element shows a tapered shape in the aspect, the contours of the cross section of this saddle are smoothly rounded.
FIGS. 6A and 6B show two enlarged cross-sections of the schematic design of rigid supporting elements for producing spade-shaped vault-structured material sheets with re-elongation of the material in order to further improve the inherent stability. In FIG. 6A, the elastic or hydraulic cushion 5 presses against material sheet 1 and supporting element 3 and thus triggers the vault-structuring process. In this process the vault troughs of material sheet 6 at first form freely and possess large plastification reserves. In FIG. 6B, if cushion 5 presses against the material sheet with increased pressure, the material is re-elongated in the area of the vault troughs 7 . The flow of the material 1 in the direction of the vault trough is stopped or restricted due to the friction between material sheet 1 and supporting element 3 , so that the material sheet 1 does not tear in the region of the upper rounded contour of supporting element 3 . This frictional effect is obtained by geometrical adjustment to the supporting elements 3 of an involute 8 .
FIGS. 7A and 7B show the basic structure of a device for application of the process according to the invention for producing a profiled can 9 by means of a supporting element roller 10 and a flexible pressure roller 11 (in cross section in FIG. 7 A and longitudinal section in FIG. 7 B). The supporting roller 10 , which is smaller than the diameter of the can, is inside the can and the pressure roller is outside it, so that the vault-structuring described above takes place.
FIG. 8 shows the basic structure of another device for application of the process according to the invention for producing profiled cans. Instead of the flexible pressure roller, a concave-shaped, flexible cushion 12 , which closely conforms to the can body and ensures even distribution of the pressure on the can body and the supporting element roller 14 , presses against the can body 13 .
FIG. 9 shows the side view of a spade-shaped vault-structured can with tapering vault folds in axial direction.
A benefit of the vault-structuring according to the invention is that rolled material sheets with increased inherent stability in the direction of rolling (anisotropic) can be provided with the same inherent stability in all directions (isotropic behavior).
Although the present invention has been described with reference to specific embodiments, it is appreciated by those skilled in the art that changes in various details may be made without departing from the invention defined in the appended claims.
The published PCT application to which the present U.S. application corresponds, namely PCT/EP97/01465, the published Fed. Rep. of Germany application from which it claims priority 196 11478.0, as well as all documents cited in the International Search Report issued thereon, including Fed. Rep. of Germany Patent No. DE 44 37 986 issued to Mirtsch on Apr. 25, 1996, International Application No. WO 94 22612 issued to Mirtsch on Oct. 13, 1997, Fed. Rep. of Germany Patent No. DE 43 11 978 issued to Mirtsch on Apr. 21, 1996, Fed. Rep. of Germany Patent DE 23 18 680 issued to Baier K G Maschinenfabrik GEB on Oct. 31, 1974, French Patent No. 1 463 640 issued to Hartman on Dec. 23, 1966, Fed. Rep. of Germany Patent No. DE 20 23 775 issued to Deutsche Tafelglas A G on Jan. 13, 1972, Patent Abstracts of Japan, vol. 007, no. 244 (M-252) dated Feb. 28, 1983, and Japanese Patent No. JP 58 131036 issued to Tokyo Shibaura Denki K K on Aug. 4, 1983, are hereby expressly incorporated by reference as if set forth in their entirety herein.
The components disclosed in the various publications, disclosed or incorporated by reference herein, may be used in the embodiments of the present invention, as well as, equivalents thereof.
The appended drawings in their entirety, including all dimensions, proportions and/or shapes in at least one embodiment of the invention, are accurate and to scale and are hereby included by reference into this specification.
All, or substantially all, of the components and methods of the various embodiments may be used with at least one embodiment or all of the embodiments, if more than one embodiment is described herein.
Some examples of structures in which the present invention may possibly be used are as follows:
U.S. Pat. No.
Inventors
Title
German Laid Open
Hollman,
Lining for shafts and
Patent Appln. DE-0S
Meissner,
roadways in mining and
28 00 221.3
Spickernagel
tunneling
and German Patent
No. P 28 00 221
German Laid Open
Hollman,
Lining for shaft and
Patent Appln. DE-0S
Spickernagel
roadways in mining and
28 00 222.4
Rawert
tunneling
and German Patent
No. P 28 00 221
U.S. Pat. No. 4389792
Fuchs
Drill core inclinometer
U.S. Pat. No. 4251108
Nocke
Method of and an
arrangement for longwall
mining
U.S. Pat. No. 4344357
Mittelkotter
Apparatus for extending
ventilating conduits
U.S. Pat. No. 4361079
Christensen et al.
Apparatus for extending
ventilating conduits
All of the patents, patent applications and publications recited herein, and in the Declaration attached hereto, are hereby incorporated by reference as if set forth in their entirety herein.
The corresponding foreign and international patent publication applications, namely, Fed. Rep. of Germany Patent Application No. 196 14478.0, filed on Mar. 23, 1996, and PCT/EP97/01465, filed on Mar. 22, 1997, having inventors Frank Mirtsch, Olaf Büttner, and Jochen Ellert, and International Application No. PCT/EP97/01465 filed on Mar. 22, 1997, as well as their published equivalents, and other equivalents or corresponding applications, if any, in corresponding cases in Fed. Rep. of Germany and elsewhere, and the references cited in any of the documents cited herein, are hereby incorporated by reference as if set forth in their entirety herein.
The above discussed embodiments of the present invention will be described further hereinbelow with reference to the accompanying figures. When the word “invention” is used in this specification, the word “invention” includes “inventions”, that is, the plural of “invention”. By stating “invention”, the Applicants do not in any way admit that the present application does not include more than one patentably and non-obviously distinct invention, and maintains that this application may include more than one patentably and non-obviously distinct invention. The Applicants hereby assert that the disclosure of this application may include more than one invention, and, in the event that there is more than one invention, that these inventions may be patentable and non-obvious one with respect to the other.
The details in the patents, patent applications and publications may be considered to be incorporable, at applicant's option, into the claims during prosecution as further limitations in the claims to patentably distinguish any amended claims from any applied prior art.
The invention as described hereinabove in the context of the preferred embodiments is not to be taken as limited to all of the provided details thereof, since modifications and variations thereof may be made without departing from the spirit and scope of the invention. | According to the invention thin sheets of foil are stiffened in a particular way by means of vault-structuring. The vault-structuring occurs either by self-organizing or following a self-organized design with a spade-shaped or drop-shaped pattern. | 1 |
This application is a continuation of application Ser. No. 245,611, filed Sept. 19, 1988, now abandoned.
BACKGROUND OF THE INVENTION
This invention relates to electronic postage meters and metering systems, and particularly to an improved method and apparatus for insuring the validity of a postal indicia printed by a postage metering system. The terms electronic postage meter and metering system, as used herein, also refer to other similar systems, such as parcel registers and tax stamp meters that dispense and account for value, and generally to systems for applying indicia to items to verify payment, or other status for that item.
Since a postage meter may be looked upon as a machine for printing money (i.e. symbols having value) security has always been considered the heart of postage meter operation. In prior postage meters indicia are printed by letter press, using a uniquely engraved dye containing postal information; the information being such that the metered postage indicia is traceable to a particular postage meter. Newer postage meters have been developed that include electronically controlled printers such as thermoprinters, ink jet, or dot matrix pin printers for printing the indicia. While these newer meters work well in concept, they have significant security problems which must be addressed since such indicia are easily printed by anyone having a suitably programmed computer and an appropriate printer. One way to insure the validity of a particular indicia has been to encode a message in the indicia in such a manner that an unauthorized person who does not know the encryption scheme cannot reproduce the appropriate encoding. Such meters using encoded information in the indicia are disclosed, for example in co-pending application Ser. Nos. 724,372, to: Arno Mueller, filed Apr. 7, 1985 and in a co-pending application by R. Sansone, entitled: POSTAGE AND MAILING INFORMATION APPLYING SYSTEM, filed Aug. 6, 1985, both assigned to the assignee of the present application.
In a system disclosed in application Ser. No. 515,073, to: John Clark, filed July 18, 1983, and assigned to the Assignee of the present invention, there is taught another method and apparatus for producing coded indicia. This application teaches encoding such that the indicia is printed in human readable form with the pixels forming the indicia modified, by voids or displacements or the like, to produce a coded message which can then be decoded to verify that the coded information is identical to the human readable information of the indicia.
Such systems generally are operative for their intended purpose, but suffer from limitations and disadvantages. First, in many cases the encryption scheme used to encode the information may be relatively simple and subject to attack by sophisticated computer analysis. Once a dishonest user is in possession of the encryption scheme used, he would be in a position to generate undetectable counterfeit indicia. When it is considered that high volume mailers, such as insurance companies, credit card companies, or oil companies may spend hundreds of thousands, if not millions, of dollars per year on postage, the incentive for such attacks can easily be seen. Another disadvantage of the above schemes is that, while it is highly desirable to use a distinct encryption key for each postage meter so that a breach of security for a single meter will not jeopardize the entire meter population, using conventional encryption, this approach would require that the postal service maintain a data base of keys for each of the hundreds of thousands of postal meters in service.
As is described in the commonly assigned U.S. Pat. application Ser. No.: 140,051; to: Jose Pastor; for: SYSTEM FOR CONVEYING INFORMATION FOR THE RELIABLE AUTHENTICATION OF A PLURALITY OF DOCUMENTS; filed Dec. 31, 1987 (C335) these problems are solved by the use of "public key" encryption systems, such as the generally known RSA encryption system. These systems provide two keys, one of which may be used to encrypt, but not decrypt, a message, and a second key which is used to decrypt the message. By use of such a public key system in the manner described in the above referenced patent application, the disclosure of which is hereby incorporated by reference, distinct encryption systems may be provided for each meter, yet the postal service need only maintain a single public key system to validate indicia. However, the use of the system taught in the above referenced patent application and the security of public key encryption schemes, both require that large amounts of information, on the order of from 100 to 200 decimal digits be printed on mail piece. Clearly, printing of such information in a conventional form as a string of decimal digits would be unacceptable.
Accordingly, it is an object of the present invention to provide a method for the validation of the status of an item, and particularly to validate the payment of postage on a mail piece.
More particularly, it is an object of the present invention to validate a status of an item by applying an indicia representative of large amounts of encrypted data in an acceptable manner.
BRIEF SUMMARY OF THE INVENTION
The above objects are achieved and the disadvantages of the prior art are overcome in accordance with the subject invention by means of an indicia applied to such item, and a method and apparatus for applying such indicia, which indicia represents an encrypted message and has the form of one or more characters selected from a set of characters consisting of N characters formed as connected graphs; the N characters forming a base N number system. In accordance with the subject invention, each of the characters is at least partially identified by the number of type 1 points and the number of type 3 points in each of said characters. (As used herein, the phrases "type 1", "type 2", "type 3", etc. refer to nodes in a graph at which the specified number of branches connect. That is, a "type 1, " is node at which one branch connects, a "type 2, " is a node at which two branches connect, etc.
In another, embodiment of the subject invention the nodes of the graphs comprising the characters are positioned on a predetermined grid and the numeric values are further determined by the spatial relationship between the type 1 and type 3 points.
In still another embodiment of the subject invention, the numeric values are still further determined by geographic features of the characters. ("Geographic features" as used herein refers to areas of a character which are partially or fully enclosed by the graph comprising the character. More particularly, fully enclosed areas are sometimes referred to herein as "lagoons" and partially enclosed areas are sometimes referred to as "bays".)
In still another preferred embodiment of the subject invention, the message is encrypted using a public key encryption system such as RSA.
Thus, it may be seen that the above objects are achieved in accordance with the subject invention in a manner which is particularly advantageous for use with postage meters and similar systems using various forms of conventional, computer control printing, such as ink-jet printers, or matrix printers. Other objects and advantages of the subject invention will become apparent to those skilled in the art from consideration of the attached drawings and the detailed description set forth below.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a block diagram of a system for printing an indicia in accordance with the subject invention.
FIG. 2 shows a flow chart of the operation of the system of FIG. 1.
FIG. 3 shows an illustration of requirements placed on characters in accordance with one embodiment of the subject invention to enhance recognition.
FIGS. 4-6 shows characters in accordance with one embodiment of the subject invention having zero type 1 and zero type 3 points, 2 type one and zero type 3 points, and 1 type one and one type 3 points, respectively.
FIG. 7 shows an illustration of the recognition of characters in the group of characters having zero type 3 and 2 type 1 points in accordance with one embodiment of the subject invention.
FIG. 8 shows a flow chart of the generation of a unique character set in accordance with the subject invention.
FIG. 9 shows a mail piece marked with postal indicia in accordance with the subject invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a postage metering system 10 in accordance with the present invention. System 10 includes CPU, or microprocessor 12 which operates under control of a program residing in PROM 14 and controls the basic meter functions, performs calculations based on any input data, and controls the flow of data into various memories. Typically, a random access memory (RAM) 15 is connected to CPU 12 for the storage of real time information and for real time accounting of critical information including the updating of ascending and descending meter registers, which record the postage value expended and available respectively. The register values are then stored in more permanent form in non-volatile memory 16 either when power is interrupted or on a real time basis, as is well known in the art.
The system operates in accordance with data (e.g. the postage value to be metered) supplied from an input, such as keyboard 18 or from another remote communication device. Such operation of postage meters is well known and is described, for example in U. S. Pat. No. 4,301,507 to Soderberg.
Metering system 10 differs from conventional postage meters using letter press printing in that CPU 12 is coupled to conventional, non-secure printer 20. Printer 20 receives print signals from CPU 12 for printing of postal information on an envelope, label or the like. Printer 20 may be a conventional dot-matrix pin printer, or anyone of a number of like devices, such as ink jet printers, thermal printers, or LED printers, suitable for receiving electronic signals and applying corresponding pixels to an item.
As also seen in FIG. 1 CPU 12 is coupled to encryption/transformation module 22. Module 22 operates on data to generate an encrypted message in the manner described in the above referenced commonly assigned patent application Ser. No.: 140,051. This message is preferably encrypted using a public key encryption system, most preferably RSA, and formatted as a number in a base N number system as will be described further below.
FIG. 2 shows a flow chart of the functions performed in module 22. It will be understood by those skilled in the art that, while module 22 is shown as a physically separate module including a microprocessor, which communicates in a conventional manner with CPU 12, that, depending upon the computational power of CPU 12, the functions shown in FIG. 2 may be performed by means of a program stored in PROM 14 and executed in a conventional manner by CPU 12.
Digital data is input and encrypted at 30 in accordance with public key 34 as is described in the above referenced commonly assigned patent application Ser. No. 140,051. At 38 the encrypted data is formatted as a number in a base N number system and, preferably, an error code is generated and added. (The error code is conventional and may be a simple parity bit or may be a more extensive error detecting or correcting code.) At 40 appropriate characters to represent the encoded data as a number in a base N number system are selected.
To represent 100 decimal digits in a base N number system, approximately 100 divided by log 10 N characters selected from an N character set are required. As will be described further below in accordance with one embodiment of the subject invention, a character set having in excess of 1,000 characters may be defined on a two by three rectangular grid (i.e. a grid having 12 intersections) and (assuming 200 pixels per inch, 10×15 pixels per character) the 100 decimal digits can be printed as a block of approximately 33 characters in an area approximately 1.6×0.2 inches. Further, as will be described below, since the character set is particularly selected in accordance with the subject invention for ease of recognition and is easily partitioned into sub groups, it is believed that this recognition can be achieved with equal or superior accuracy to the recognition of conventional decimal digits without substantial increase in the time required for recognition.
In one embodiment of the subject invention, the characters are selected from the set of connected graphs which may be drawn on a 2×3 rectangular grid. That is the allowed nodes of the graphs are arranged in a 3×4 rectangular array and only horizontal or vertical branches are allowed. For such graphs the following properties may be demonstrated (where n1 and n3 equal the number of type 1 and type 3 points respectively and a type 4 point is, by definition, taken as two type 3 points.):
n.sub.1 +n.sub.3 is even, and
n.sub.1 max=n.sub.3 +2
For further ease in recognition the possible characters are limited in accordance with one embodiment of the subject invention by the requirements that:
The character completely traverse the grid. That is a connected path exist from the left edge to right edge and from the top to bottom of the grid for each character.
All bays must be completely open. That is, if a bay opens to the east, that opening must be coextensive with the west boundary of the bay.
All bays must be concave and simple. That is, all bays must be formed by only three or two segments.
Characters 50, 52 and 54 shown in FIG. 3 illustrate the failure to meet each of the above requirements respectively.
FIGS. 4-6 show characters generated in accordance with the above requirement which have zero type 1 points and zero type 3 points, 2 type 1 points and zero type 3 points, and 1 type 1 point, and 1 type 3 points. Table 1 below shows the total number of graphs meeting the above requirements grouped according to the numbers of type 1 and type 3 graphs. The total number of points meeting the above requirements has been determined to be, as shown in Table 1, 8,497; which would result in a reduction by a factor of log 10 8,497=3.92 in the number of characters required to represent a number expressed in decimal digits. (i.e. 100 decimal digits requires approximately 20 characters, 200 approximately 51 characters, etc.)
TABLE ONE__________________________________________________________________________ Type 3 PointsType 1 Points 0 1 2 3 4 5 6 7 8 Total__________________________________________________________________________0 1 40 411 96 296 3922 42 611 724 13773 394 1204 652 22504 89 885 942 216 21325 340 698 316 20 13746 56 322 222 41 1 6427 94 100 28 2228 13 32 10 1 569 8 2 1010 1 1Total 202 932 1890 2300 1898 996 258 20 1 8497__________________________________________________________________________
While it is within the contemplation of the subject invention to use the entire character set identified in Table 1, and even to reduce the requirements set forth above to make use of even larger character sets, it is preferred to further restrict the character set so that the characters may be unambiguously identified using a minimal number of descriptive characteristics. This is illustrated with respect to one subgroup of characters in FIG. 7. In accordance with a feature of the subject invention, a scanned character is first grouped by the number type 1 points and the number of type 3 points in the graph, in this case characters having 2 type 1 points and 0 type 3 points. If no further recognition were done, only one character could be selected for the character set from each subgroup of characters. Accordingly, in a preferred embodiment of the subject invention the characters are further identified by the spatial relationships between the type 1 and type 3 points. Thus, at step 60 shown in FIG. 7, each character is classified in accordance with the spatial relationship between the two type 1 points. Thus, where the points are above each other, the character is classified I, where the points are adjacent, the characters classified II, where the points are on a positive diagonal, the character is classified III, and where the points are on a negative diagonal, the character is classified IV. Thus, four characters may be identified from the group having two type 1 points and zero type 3 points based upon a simply determined relationship between the two points. Those skilled in the art will immediately recognize that a much larger number of characters can be recognized from other subgroups based simply upon the spatial relationship between the type 1 and type 3 points, and that if the total number N of characters points selected based on this description is considered sufficient, a remarkably simple and efficient character recognition scheme is provided.
However, in other embodiments of the subject invention, a larger value for N may be desired. In this case the characters must be further described. Thus, at 62 in FIG. 7 the characters classified in classification 3 are further described in accordance with geographical features. This description shows that one character has a bay opening to the northeast, two characters have bays opening to the northeast over bays opening to the southwest, one character has a bay opening to the southwest, one character has a bay opening to the southwest adjacent to a bay opening to the northeast, two characters have bays opening to the west over bays opening to the east, and one character has a bay opening to the west over a bay opening to the west over a bay opening to the east over a bay opening to the southwest. By discarding one character from each of the two sets of duplicate characters, six characters may be generated from the subgroup having two type 1 points and 0 type 3 points, classification 3. Again, those skilled in the art will recognize that description in terms of geographical features will again greatly increase the number of characters which may be distinguished and provide a larger value for N.
If it is desired to use the entire set of possible characters (i.e. the full 8,497), metric characteristics must be obtained to distinguish those characters which may not be distinguished in terms of the spatial relationships between the type 1 and type 3 points and the descriptions in terms of geographic features. At step 64 it may be seen that the two pairs of duplicate characters can be distinguished on the basis of whether the larger feature is above or below the smaller. In general however, it is believed preferable to limit the character set to characters which may be distinguished without resort to metric characteristics.
Those skilled in the art will recognize that other characteristics of the characters could be used to identify them. For example, characters in FIG. 7 classified in the zero classification could be further distinguished based on whether the points were on the left or right edge of the grid.
FIG. 8 shows a flow chart of the generation of an unambiguous character set in accordance with the subject invention.
At 70 the character requirements, e.g. that the characters are defined on a 2×3 rectangular grid, that the characters traverse the length and width of the grid, etc. are input along with the relevant descripters, e.g. the number of type 1 and type 3 points, the spatial relationship between such points, geographic features, etc. An index counter m is said equal to 0 and a file, herein referred to as the "Dictionary", is established.
By Dictionary herein is meant a listing in terms of the input descriptors and an associated identification, typically a number from 0 to N-1.
A convenient and preferred arithmetic whereby a description of a character may be notated and ordered is described in commonly assigned, co-pending U.S. application Ser. No.: 924,473; to: Jose Pastor et al.; for: OPTICAL CHARACTER RECOGNITION BY FORMING AND DETECTING MATRICES OF GEO FEATURES; filed: Oct. 29, 1986 (C-273), which is hereby incorporated by reference.
At 72 counter m is incremented and at 74 the mth graph is generated. A correspondence between graphs and the value of counter m is easily established by associating each possible branch, of which there are 17 for a 2×3 grid, with one digit of a binary number, the graph then includes a branch for each digit having a value of 1, thus giving 2 17 -1 possible graphs. At 78 the mth graph is tested to see if it meets the requirements, e.g. does it fully traverse the length and width of the grid, are all bays completely opened, etc. If not, at 72 m is incremented again, and at 74 the next graph is generated. Then at 80 a description in terms of the relative descriptors is generated and compared to all other descriptions in the Dictionary. At 82 the description is tested to see if it is not in the dictionary. If it is in the dictionary, the process again returns to 72 to generate the next graph. If it is not in the dictionary, at 86 the graph is stored, as a description associated with a unique selected value, i.e. a number from zero to N-1, and at 88 counter m is tested to determine if all possible graphs have been generated. If they have not, the process again returns to 72, if they have the process exits.
The result of the process shown in FIG. 8 is a set of characters with unique descriptions each associated with a number from 0 to N-1. If it is believed that the value for N is not great enough, the process may be repeated using a further level of description to generate a larger character set, the character requirements may be relaxed, or a larger grid may be used to generate the characters. Conversely, if it is believed that the recognition logic for the resultant descriptions is too complex, a simpler set of descripters may be selected.
In recognizing a character, it is within the contemplation of the subject invention to fully scan each character to determine a complete description in accordance with the selected descripters and find the resulting description in the dictionary or to first scan the character to determine the number of type 1 and type 3 points and then select appropriate levels of description based on the number of such points. For example, it may prove desirable to describe the smaller subgroups in terms of the number of type 1 and type 3 points, the spatial relationship between such points, and geographic features; while describing larger subgroups, which as can be seen from Table 1 may include up to more than 1,000 possible graphs, only in terms of the number of type 1 and type 3 points and their spatial relationship. However, as noted above, it is a feature of the subject invention that the primary classification of each scan character is based on the number of type 1 and type 3 points and further rules for recognition, whether in the form of a dictionary or otherwise, are selected accordingly. It is preferred that, in this initial classification, type 4 points be considered equivalent to two type 3 points, though a distinction between type 4 and type 3 points may be made in any further recognition rules.
FIG. 9 shows an item to be mailed 50 (i.e. an envelope) marked with an indicia 52 produced in accordance with the subject invention. Indicia 52 includes the following plain text information relating to the item, a postage amount 54, a date 58 on which the item was metered, and I.D. number 60 for the meter, and a second I.D. number 62 for the postal station to which the item is to be delivered in accordance with U.S.P.S. regulations for metered mail. Indicia 52 also includes a number in an N base numeric system 66 representing the result of a public key encryption of at least a portion of the plain text information together with additional information as described in the above reference commonly assigned U. S. Pat. application Ser. No. 140,051. The 40 characters shown are equivalent, assuming that the entire 8,497 character set is used, to approximately 157 decimal digits; ample to provide security for a message encrypted with the preferred RSA encryption technique.
The above description and drawings have been provided by way of illustration only and will enable those skilled in the art to recognize numerous other embodiments of the subject invention. Accordingly, limitations on the subject invention are to be found only in the claims set forth below. | An item bearing an indicia which verifies a status of the item and a method and apparatus for applying such indicia. The indicia represents an encrypted message and has the form of a number n base N number system represented by characters selected from an unambiguous machine-readable character set having n characters. The characters consist of connected graphs drawn on a predetermined grid and meeting certain selected requirements. A set of descripters is selected, including a number of type 1 and type 3 points in a character and a subset of characters is selected from the set of all possible characters meeting the requirements so that each character is unambiguously described in terms of the selected descripters. In one embodiment disclosed the item is a mail piece and the status is the payment of postage. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a printing system and to a printer unit for use in such a system.
BACKGROUND TO THE INVENTION
[0002] In the state of the art, a number of printers arranged to be manually placed on an image receiving medium are known. The printing means of the printer or the entire printer is operable to scan over the image receiving medium in the printing operation. Thus, the medium is not fed through the printer—as in most office sheet printers, but the printer is placed upon the medium.
[0003] Such a printer is known from EP 564297-A. The printer has an ink jet print head which is scanning in two orthogonal directions over the image receiving medium, onto which the printer is placed manually. The printer is connected to a computer and capable e.g. of printing addresses onto envelopes, but can also be used separately from the computer for printing data downloaded from the computer to the printer.
[0004] Another ink jet printer to be placed on a printing medium is disclosed in U.S. Pat. No. 5,634,730 A. This printer is provided with a keyboard for data inputting, but can also print images downloaded from a computer. The print head scans over the image receiving medium along a special path, e.g. helically or like a pendulum. It can print data downloaded from a computer or one of a set of predetermined words such as “PAID” etc.
[0005] DE 3142937-A refers to a so-called hand stamp which is placed manually on the image receiving medium. It can print data downloaded from an accounting machine, or images consisting of user-selected fixed phrases. The hand stamp has a thermal print head and an ink ribbon for printing.
[0006] The printers known in the prior art are thus capable of printing an image onto an image receiving medium, and make use of a scanning print head. Printing is performed in two steps: the first one is alignment of the printer on the image receiving medium such that the image can be printed in the desired position and the second step is printing. However, although the printers can communicate with a computer to receive data to be printed, that is the limit of their interaction. There is no other active cooperation between the printer unit and a computer.
SUMMARY OF THE INVENTION
[0007] It is one aim of the present invention to provide a printing system in which there is more active cooperation between a computer and the printer unit.
[0008] According to one aspect of the invention there is provided a printing system comprising:
[0009] a printing unit;
[0010] a base station configured to receive the printing unit when not in use and having means for detecting movement of the printing unit from the base station;
[0011] a computer connected to the base station and configured to execute a printing application for generation of printing data for the printing unit,
[0012] wherein said printing application is initiated by the computer when movement of the printing unit from the base station is detected.
[0013] Another aim of the invention is to provide a printer unit for use in a printing system which has a wider range of user interface functions.
[0014] According to another aspect of the invention there is provided a printing system comprising:
[0015] a printing unit; and
[0016] a computer connectable to the printing device and configured to execute a printing application for generation of printing data for transmission to said printing device for printing;
[0017] wherein the printing system includes a memory which holds a plurality of default printing data options each having associated therewith a time activation period and means for determining the time at which the printing application is initiated, wherein the printing application includes a default output sequence for generating one of said default printing data options in accordance with the detected time of initiation of the printing application.
[0018] This allows a user profile to be recognised so that the printing system is responsive to a user's requirements. The memory may be in the computer or within the printing unit.
[0019] A further aspect of the present invention provides a printer adapted for communication with a host computer, the printer comprising:
[0020] communication means for receiving printing data to be printed from the host computer while a communication link exists between the printer and the host computer, said printing data defining a sequence of images to be printed;
[0021] a data path for conveying data received at the communication means to a printing mechanism for printing said data;
[0022] a user input means for instigating a print command; and
[0023] a controller connected to the printing mechanism and operable to allow the printing mechanism to print successive images in the sequence, each successive image being printed responsive to the user instigated print command.
[0024] This feature can be used with the printer connected to the computer and for receiving successive images therefrom, or at a location remote from the host computer when the communication link is broken. In that case, the printer can have a store for holding the printing data.
[0025] In addition, this aspect of the invention provides a method of printing a series of images comprising:
[0026] establishing a communication link between a printer and a host computer;
[0027] transferring printing data defining said images from the host computer to the printer;
[0028] breaking the communication link and moving the printer unit to a location remote from the host computer; and
[0029] at the remote location, printing successively each image in the sequence responsive to a user instigated print command at the printer unit at said remote location.
[0030] According to an alternative aspect of the present invention, there is provided a method of printing a series of images comprising:
[0031] establishing a communication link between a printer and a host computer, the printer including user input means for instigating a print command; and
[0032] successively transferring printing data defining each image in the sequence from the host computer to the printer and printing said each image responsive to a user instigated print command.
[0033] Another aspect of the invention provides a printing system comprising:
[0034] a printing unit including user input means for instigating a print command;
[0035] a base station configured to receive the printing unit when not in use;
[0036] a computer connected to the base station and configured to execute a printing application for generation of printing data for the printing unit, the computer comprising a keyboard; and
[0037] wherein execution of the printing application is interrupted by operation of any key on the keyboard of the computer or the user input means on the printing unit.
[0038] One key of the keyboard may be defined as a “hot key” which remains active as the application is running such that when the hot key is depressed, a particular function is initiated.
[0039] For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] [0040]FIG. 1 is a plan view showing a printer, a base station and a computer;
[0041] [0041]FIG. 2 is a view of the printing mechanism of the printer;
[0042] [0042]FIG. 3 is a view of a printer in use;
[0043] [0043]FIG. 4 is a flow diagram of the software printing application;
[0044] [0044]FIG. 5 is a block diagram illustrating time related activation default options; and
[0045] [0045]FIG. 6 illustrates a sequence of images to be printed.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] [0046]FIG. 1 shows a printing system consisting of a computer 10 , a computer controlled display 12 , which is in the described embodiment of the invention a CRT, a keyboard 14 linked to the computer 10 by means of a cable 16 , another cable 18 , connecting the computer 10 with a base station 20 , which is connected to a printer 24 by means of a cable 22 . Thus, the printer 24 is linked to the computer via the cables 18 , 22 and the base station 20 .
[0047] As known in the prior art, the computer 10 comprises a processor on which a software is running, comprising an operating system, a printer driver to enable printing with the printer 24 from the operating system and a software application by which data can be created, selected and formatted on the PC, for defining image patterns to be printed by the printer 24 . The software application can be activated in a number of ways:
[0048] selected by the user at start-up or from the desktop: the user places the software application in the start-up directory or creates an icon on the desktop;
[0049] from within another application: the user invokes the software application from a button (displayed on the display 12 ) in the toolbar of another software application or from its own floating toolbar.
[0050] from the handheld printer 24 itself: if the application is not running, the user presses a print button 34 on the handheld printer 24 , which will automatically invoke the software application in the first instance.
[0051] According to an embodiment of the invention, however, the software application is activated on the computer 10 for controlling the printer 24 by lifting the printer 24 off the base station 20 . A switch 32 is provided in the base station 24 sensing the presence or absence of the printer 24 by means of a pin 30 . When the printer 24 is placed upon the base station, the pin 30 is depressed, and the switch 32 is closed. In the case that the printer 24 is removed from the base station 20 , the pin 30 which is biased in the vertical direction moves upwardly and the switch 32 opens. The switch is connected via some electronic circuits to the computer 18 and activates the software application for printing. Conversely, when the printer 24 is returned to the base station, the state of the switch is detected to automatically return the computer to the main application which it was executing when the printer was removed. This functionality is described in more detail later with reference to FIG. 4.
[0052] That is, a default printing application on the computer changes to the present printing application when it is “activated” by one of the techniques mentioned. When it is “deactivated”, the default printing application is returned to an original printing application.
[0053] The base station 20 is connected to the computer 10 by means of the cable 18 , which can be a parallel or a USB cable. Electric power is supplied to the base station 20 by a separate mains transformer, but could also be supplied from the computer via the cable 18 , preferably when the cable 18 is a USB cable. The cable 18 can be hard-wired to the base station 20 , or connected to a socket of the base station, which is preferably provided at the rear thereof. When the printer 24 is not in use, the handheld printer will be placed in the base station 20 . The base station 20 will ensure that the ink jet print head of the printer 24 is protected when not in use by a capping device that will be automatically triggered whenever the printer is inserted into the base station 20 . The base station 20 will also cause the print head of the printer 24 to eject ink into a reservoir and mechanically clean the surface of the print head. These measures are necessary to maintain optimum print quality.
[0054] The umbilical cable 22 connects the base station 20 to the hand held printer 24 , providing both power and data. A LED on the printer will indicate that power is on. The printer 24 is removed from the base station 24 and positioned on the surface to be printed. The length of the cable 22 limits the distance of travel from the base station.
[0055] In another embodiment of the invention, the printer is arranged to be disconnected from the base station by unplugging the umbilical cable 22 and moved to another location wherein printing of the contents of on-board memory, i.e. downloaded image data, can be effected. The user will employ scroll buttons on the printer to select the required print data, which appear in a small LCD. Once a selection has been made, pressing the print button 34 will activate printing. Having selected the data to print using the software application (or the scroll buttons on the printer), the user will activate printing from the print button 34 on the hand held printer 24 itself.
[0056] According to a further alternative, data for printing can be sent to the printer using RF or IR technology. The scroll buttons may be used to select data which may be stored on the “smart card” or which resides in the computer.
[0057] Print alignment is achieved visually through a transparent window 36 in the print casing. This window 36 can also be opened for inserting an ink cartridge into the printer 24 before use. The cartridge is then clamped in a carriage of the printer 24 . The window 36 must be closed before printing; thus there is a switch provided in the housing of the printer for detecting whether the window is closed or not. When the window 36 is not closed, the switch disables printing. Changing a cartridge is achieved by lifting a retaining lever and extracting the cartridge in use and replacing this with a new or different colour cartridge in the way described above. If the removed cartridge still contains ink and is to be reused it must be capped to avoid the ink drying out.
[0058] Alternatively a Think jet type head from Hewlett Packard may be used which utilises a different type of ink which does not dry out in the print head.
[0059] The printer 24 contains a print mechanism with the ink jet print head having a number of print nozzles, and an ink supply. The print head is moved by means of motor driven scanning means within the housing in two (generally orthogonal) directions such that a rectangular area can be imprinted through an aperture of the printer 24 at the bottom of its housing. Thus, the printer 24 is placed manually on an image receiving medium and—when the print button 34 is depressed—the print head scans over the medium and imprints it by spitting ink droplets onto it.
[0060] [0060]FIG. 1 shows the presence of a “Smart Card” reader 28 in the base station 20 . Smart cards 26 , i.e. memory cards, may be used for storing data or images or as a substitute for additional RAM in the base station.
[0061] In another embodiment, a printer is provided which can only be used as a standalone device, i.e. in cooperation with a base station. The functionality of the printer is then as follows: the user removes the printer from the base station. A single button 36 (see FIG. 2) will switch the printer on and off, and a LED on the printer will indicate that power is on. A ROM card containing the selected image data is inserted into the printer. The ROM card is printed with images of its content and the sequence of images provided on the ROM card is indicated numerically on a display of the printer. Thus, the user will select the desired image using scroll buttons to scroll forward or backwards through the numbered content. The user will activate printing from the button 36 on the handheld printer itself.
[0062] The print mechanism of the printer will now be described with reference to FIG. 2. The printer 24 has a housing, the underside of which can be abutted against the surface of the image receiving medium to be printed. A print face 11 is defined by the scanning range of an ink jet print head cartridge 126 which can be replaced using the cartridge release mechanism described above. The ink jet print head cartridge 126 is mounted for movement along a write axis 128 by virtue of a cooperating lead screw 130 and nut 132 . The movement is controlled by a stepper motor 134 . The position of the writing axis 128 can be altered by an indexing axis lead screw and bush 136 controlled by a further stepper motor 138 . Reference numeral 140 designates a stability bar which extends parallel to the write axis 128 , the ink jet print head cartridge 126 being mounted between the write axis 128 and the stability bar 140 . Reference numeral 142 designates an indexing axis stability bar and bush.
[0063] The printer also includes an electronic controller 100 having a microprocessor for controlling movement of the stepper motor 34 and generating signals for controlling the print head and having a buffer memory for storing data. The microprocessor is capable of converting data from a computer to which the device is connected into a format suitable for driving the print head. The buffer memory can store information in a variety of formats to enable the printer to work with a variety of computer equipment.
[0064] If a Think jet print head is used, a DC motor and encoder may be used in place of a stepper motor.
[0065] In FIG. 3, a printer 24 positioned on an image receiving medium 40 is shown ready for use. That is, it has been removed from the base station 20 and placed on the medium 40 to be printed. In doing so, the application software is automatically initiated to allow printing data to be selected and configured by a user using the computer 12 and keyboard 14 .
[0066] Some aspects of the application software will now be described with reference to FIGS. 4 to 6 . In addition to the automatic initiation of the application, the application allows for a number of default print options depending on a user profile as will now be described. FIG. 4 is a flow chart of the printing application. Assume the computer is executing a main application (step SO) and the printer 24 stands ready for use on the base station 20 . At step S 1 , the state of the switch is monitored by the application software to determine whether or not the printer unit 24 is on the base station 20 . When the printer unit 24 is removed from the base station 20 , at step S 2 the printing application is initiated by the computer. At step S 3 , the printing application determines whether or not default options are set. If no default options are set, a number of print options are displayed on the PC display at step S 4 from which a user may select his required option at step S 5 . Alternatively, a user may simply use the printing application initiated at step S 2 to create, select and format printing data using the keyboard 14 and the display 12 as with any existing printing application. However, the provision of default options simplifies use of the printing system for a user, in particular a user who has predictable requirements.
[0067] If default options are found to be set at step S 3 , the application software selects one of the default options based on the time of use, as indicated at step S 6 . This is described in more detail later. At step S 7 , print data is generated in accordance either with the user selected option at step S 5 or the default option selected by the application software at S 6 . Then, at step S 8 the printing data is transmitted to the printer 24 ready for printing.
[0068] Step S 1 is periodically implemented to check the status of the printer 24 . If it is determined to have been returned to the base station, the computer automatically returns to the main application, step S 0 .
[0069] [0069]FIG. 5 is a block diagram illustrating elements of the system to implement default options with time related activation periods. A default control block 50 selects from a plurality of default options held in a memory 52 . The selected option is used by a default output sequence 54 to generate default printing data for the printer unit 24 . Default control block 50 can be responsive to an internal clock 56 or diary function 58 of the computer system so that a default options is selected in accordance with the time of day or day of the week. Alternatively, the default options may be supplied to the display 12 where a user selects a particular option, for example using user activated icons.
[0070] For example, for options with a time related activation period, a user could set the default output to be “RECEIVED” when the internal clock 56 of the computer indicates the time between 9 am and 11 am, and from 11.01 am and 5.30 pm the default output could be an address format.
[0071] During printing, the system may be interrupted at any stage by pressing any key on the keyboard 14 or any button on the printer unit 24 itself, in particular the print command button 34 .
[0072] One of the advantages of the system described herein is that the printer unit may be used at locations remote from the computer. In particular, this is the case where the cable 22 which normally connected the printer unit 24 to the base station 20 can be detached. It may be the case that it is desired to print sequential information at a number of different remote locations, for example so as to print on a number of different products. FIG. 6 illustrates a sequence of images denoted 11 , 12 , 13 each of which carry a common part 60 of information and a sequentially varying part 62 , that is the numbers 1, 2, 3. The system described herein allows the whole sequence of images to be transmitted to the printer unit during operation of the application software (step S 8 in FIG. 4). Subsequently, each image in the sequence can be individually printed responsive to operation of the print command button 34 on the printer unit 24 . After an image in the sequence has been printed, the controller in the printer automatically selects the next image for printing on the next print command. This technique is useful for example in printing sequential numbers as illustrated in FIG. 6, barcodes or a sequence of database information.
[0073] [0073]FIG. 3 illustrates the printer in use to print a sequence of images. The first image, 11 , has been printed by the printer 24 . The printer 24 has been lifted up and relocated in a different position. On actuation of the print command button 34 , the next image, 12 , in the sequence will be printed at the new printer location. | A portable printer is provided which provides active cooperation between a computer and the portable printer unit. A number of different features are introduced into the printing unit which allow greater responsiveness from the computer responsive to actions taken at the printer unit. | 1 |
BACKGROUND OF THE INVENTION
This invention pertains to the art of vehicle instrument panels or other trim panels and more particularly to a vehicle trim panel having an air bag deployment system mounted therein and in which a door through which the air bag is to be deployed is invisible to vehicle occupants prior to such deployment.
RELATED ART
Automotive vehicles have long utilized restraint systems for the safety of vehicle passengers. Initially, such restraint systems included seat belts which fit over the occupant's lap. Later many restraint systems were modified to add an additional strap, or shoulder harness, which crossed the occupant's chest and further protected them against impacts. Of late, air bag supplemental restraint systems have become increasingly popular. A typical air bag supplemental restraint system includes an inflatable bag which is stored in a deflated condition within the vehicle steering wheel or trim assembly. Upon a relatively severe impact, the air bag is rapidly inflated and deployed into the passenger compartment through various means and openings.
Early air bag deployment systems included a requirement that the opening through which the air bag would be deployed was weakened or somehow configured to insure its successful deployment. Usually the weakened areas were thin spots or cuts in the vehicle interior trim components. The cuts were visible to the vehicle occupants and they detracted from the appearance of the vehicle interior. As such, a need arose for an effective air bag deployment system which was obscured or hidden from the view of vehicle occupants until such deployment.
U.S. Pat. No. 5,072,967 to Batchelder et al. discloses a cover assembly for an air bag restraint which has a smooth cover. An outer cover member has weakened sections on an inboard surface to facilitate deployment of the air bag through the opening created thereby. To reduce the probability of such weakened sections being visible to vehicle occupants, a filler material is placed between the weakened outer cover member and an insert to prevent inward collapse of the outer cover member at the weakened sections. In addition, an insert of aluminum is formed in the filler material and, upon deployment of the air bag, is stressed against the weakened sections of the cover member to deploy the air bag. It is a more complicated system than that of the invention.
U.S. Pat. No. 5,082,310 to Bauer discloses an arrangement enclosure for an air bag deployment opening to be formed in the interior trim structure of an automotive vehicle. The closure includes a substrate section which is weakened in a pattern to form contiguous doors or subsections which split apart along purportedly invisible seams when an air bag is inflated. Upon such inflation, the resulting pressure on the inside of the opening causes the preweakened skin of the foam plastic layer to split apart along the seams, allowing the air bag to be deployed into the vehicle interior. This arrangement requires the skin of the foam plastic layer to be weakened in a matching pattern above the seams in the substrate section. It is believed this embodiment is also more complicated than the present invention and requires that the outer skin of the vehicle interior be weakened over a substantial portion of its area for proper deployment of the air bag.
The present invention contemplates a new and improved vehicle trim panel for use with an air bag deployment system which is simple in design and which overcomes the foregoing difficulties in others while providing better and more advantageous overall results.
SUMMARY OF THE INVENTION
A door and frame in a motor vehicle interior instrument panel or other trim panel includes the panel having an inner side adapted to at least partially enclose an air bag supplemental restraint system. The panel has an outer side having a trim element designed to be viewed by a passenger in the motor vehicle. The trim element overlaps door and frame and obscures a joint between the door and frame when the panel is installed in a motor vehicle. The trim material is able to self-heal small punctures or cuts within it. A foam material on the inner side of the panel is prevented from passing through the punctures or slits in the trim material due to its self-healing characteristic. The frame is reinforced by a reinforcing member to be relatively strong in comparison to the door and deflecting much less than the door when the door and frame are equally loaded.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take physical form in certain parts and certain arrangement of parts, a preferred embodiment of which will be described in detail in the specification and illustrated in the accompanying drawings, which form a part hereof and wherein:
FIG. 1 is a side elevational view in cross-section of a door and frame in a motor vehicle interior trim panel according to the invention.
FIG. 2 is a cross-sectional view of the trim panel shown in FIG. 1 and taken at section 2--2.
FIG. 3 is a plan view of the underside of a reinforced trim element according to the invention.
FIG. 4 is a cross-sectional view of the initial configuration of slits in the trim element taken through the joint.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3.
FIG. 6 is a schematic perspective view of a typical vehicle interior in which such door and frame of the invention might be utilized.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings, the same numerals are used to designate the same components or items in several views.
With reference to FIG. 6, a typical vehicle interior is illustrated. A prominent feature of such vehicle interior is the interior instrument panel or other trim panel. For example, a typical trim panel 10 includes a trim element 12 which may cover or overlap a door 14 which is hidden from view beneath phantom joint 44.
The door 14 is inserted into and adhesively bonded to a substrate 32. The door 14 should be made of a rigid material of good impact resistance at both high and low temperatures. A preferred material is a Thermoplastic Urethane and Nitrile-Butadiene Rubber (hereinafter TPR-NBR) blend or a metal such as steel or aluminum.
The frame 16 is generally referred to as the area of the trim panel 10 near or contiguous to area 14A and which works together with the door 14 to support its movement, just as a door and frame in a house or other dwelling work together. As illustrated by the dotted lines, it is preferable that the door 14 be hidden from view by occupants in the vehicle interior until deployment of the air bag through trim panel 10 through joint 44.
With reference to FIGS. 1 and 2, the trim panel 10 includes a trim element 12 on an outer side of the trim panel 10. In the preferred embodiment, the trim element 12 is 1.5 mm thick and is made of a trim material. The trim material is preferably polyurethane or polyurea with an outer paint coating. The paint coating is also preferably a two component polyurethane. An alternative construction would be a cast vinyl trim element 12 with or without a coating. A further alternative would be a trim element 12 made of an Thermoplastic Olefin (TPO) sheet or an TPO that has polypropylene foam laminated to it. In the preferred embodiment, the trim element 12 is manufactured by spraying the urethane into a mold as will be described hereafter.
With continuing reference to FIGS. 1 and 2, the next element of the trim panel 10 is a scrim or reinforcing member 24. As will be later discussed and illustrated in FIGS. 3 and 5, the reinforcing member 24 is generally rectangular and positioned around the area 14A much like a frame is positioned around a picture, although the reinforcing member 24 is to be distinguished from the frame 16. The reinforcing member 24 can be made of any appropriate material such as scrim might be made of, but is preferably made of a fabric such as nylon or polyester. The preferred reinforcing member 24 has a pressure sensitive adhesive to attach it to the trim element 12. In an alternate embodiment the reinforcing member 24 could utilize a two component 100% solids urethane adhesive which is spread onto the trim element 12. The reinforcing member 24 is then pressed into the adhesive and pressed into position.
With continuing reference to FIGS. 1 and 2, the next layer of the trim panel 10 is a foam material 28. The foam material 28 can be any appropriately chosen adhesive foam, although the preferred foam is a two-component polyurethane foam based on polyether/polyesther type polyols with polymeric 4,4'-Diphenylmethane Diisocyanate, hereinafter MDI. In the preferred embodiment, the foam is between 5 mm and 6 mm thick and has a typical foam density of between 5.0 and 20.0 pounds per cubic foot (0.08 grams/cubic centimeter-0.32 grams/cubic centimeter).
Finally, the panel 10 includes the substrate 32 which is normally manufactured of plastic. The preferred material is SMA copolymer such as is available from Arco under the trade name Dylark. Alternate materials include GE's Noryl EM-7304 polycarbonate, steel, aluminum, magnesium, reinforced RIM or S-RIM urethanes. The substrate 32 should provide a molded-in chute for the air bag, i.e. flanges 36. The flanges 36 are formed into the substrate 32 and are useful for attaching the air bag canister (not shown). The substrate has a thickness of 3 mm to 4 mm.
With reference to FIGS. 3 and 5, the reinforcing member 24 and its function will be described in more detail. FIG. 3 is a bottom view of the inner side of reinforced trim element 12. The location and configuration of area 14A and frame 16 is seen by the joint 44 which separates them and forms their respective boundaries.
As can be seen with reference to FIG. 3, the reinforcing member 24 is generally rectangular and surrounds area 14A much like a picture frame surrounds a picture. The reinforcing member performs an important and novel function in that it strengthens the frame 16 around area 14A so that the frame 16 near the joint 44 is relatively strong compared to area 14A. Therefore, when an air bag is inflated in the process of being deployed door 14 moves toward trim element 12. The stresses generated thereby and impressed upon 14A and frame 16 are approximately equal, but the ability of area 14A to withstand those stresses without significant deflection is much less than that of the frame 16. The force applied by the upward motion of the door 14 and foam 28 immediately thereabove causes the trim element 12 to tear along joint 44. Therefore, area 14A, along the joint 44 breaks loose, allowing the air bag to be deployed. The door 14 is bonded onto the substrate 32 around upper half 90 of door 14 and lower half 92 of door 14. A first stronger adhesive is used for the upper half 90 of the door 14 while a second weaker adhesive is used for the lower half 92 of the door 14. This is to encourage the leading edge 96 of the door 14 to open before the upper half of the door 14.
In a preferred embodiment of the invention, the door 14 is hinged at one side via a door hinge 48. In such an embodiment, the reinforcing member 24 includes at least one reinforcing member hinge 52. As shown in FIG. 3, reinforcing member hinge 52 extends beneath a portion of area 14A by crossing under phantom joint 44. Upon the occasion of the deployment of the air bag, the reinforcing member hinge 52 assists and restrains area 14A foam 28 and the door 14 in their opening and revolution about the door hinge 48.
With continuing reference to FIG. 3, another important aspect of the preferred embodiment of the invention is a release element 56 which is configured on the inner side of the trim element 12 along the joint 44. Preferably, the joint 44 is coaxial with a centerline of the release element 56. A preferred release element 56 is a wax-based mold release such as is available from Chemtrend and sold under the trade name XCTWA4090. The release element 56 assists the separation of the door assembly comprising area 14A, foam 28, and door 14, from the frame 16 upon deployment of the air bag. It also performs the important function of preventing foam material 28 from adhering to the trim element 12 at joint 44 or from passing through slits or punctures 66 in the joint 44. As shown in FIG. 3, release element 56 prevent the foam material 28 from adhering to trim element 12 along a substantial portion of joint 44.
With continuing reference to FIGS. 3 and 4, a further aspect of the preferred embodiment includes weakened regions 60,61,62. Within the weakened regions 60,61,62 are weakening means for weakening the trim element 12, such as punctures or slits 66. The slits 66 have an initial configuration, immediately after their formation, as illustrated in FIG. 4. The trim element 12 has an outer side 70 and an inner side 72. This initial configuration of the slit 66 is generated by a knife or puncturing tool having the general configuration of the slit 66. More specifically, the cutting tool or initial configuration of the slit 66 has a outer surface 74 having a width of about 1 mm and an inner surface 76 having a width of about 2 mm.
One of the most important aspects of the invention is the ability of the slit 66 to transform from its initial configuration, as shown ill FIG. 4, to a second configuration where the slit 66 is undetectable from outer side 70 of trim element 12. In such case, the sidewalls 80,82 of the slit 66 move toward each other until they are adjacent, effectively closing the slit 66. This quality or characteristic is defined herein as "self-healing" meaning the punctures or slits 66 used to create the weakened regions 60,61,62 remain invisible from the outer side 70 of the trim element 12. This self-healing characteristic is dependent on the materials used for the trim element 12. The self-healing characteristic of the trim material also helps prevent foam material 28 from passing through the trim material. As stated previously, in the preferred embodiment, the trim material is a urethane or polyurethane material which is preferably sprayed to create the trim element 12. While the slit 66 appears closed and essentially invisible, the trim element 12 is weakened in certain areas by the slits 66.
A preferred method of manufacturing the trim panel 10 will now be described. The trim element 12 is placed or sprayed into a mold. Trim element 12 is reinforced around a phantom joint 44 with a reinforcing member 24. Slits 66 are formed in trim element 12 along phantom joint 44. Slits 66 are initially wider toward inner side 72 of trim element 12 and narrower toward the outer side 70 of trim element 12. Release element 56 is applied to the inner side 72 of trim element 12 along a portion of phantom joint 44 at least covering slits 66. The substrate 32 with the adhesively bonded TPU-NBR door is positioned on the lid of the mold. The foam material 28 is then introduced onto the inner side of the trim element 12 either by pouring into the open mold or by injecting it into the center of a closed mold. The urethane foam then reacts and expands to fill the mold and bond the substrate 32 and trim element 12 together. After the foam has hardened, the mold is opened and the finished part removed.
The invention has been described with reference to a preferred embodiment. Obviously, modifications and alterations will occur to others upon a reading and understanding of this specification. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A door and frame in a motor vehicle interior instrument panel or other trim panel is obscured to a vehicle occupant before deployment of an air bag located behind the trim panel. A trim element cover overlaps a joint between the door and frame. The trim element cover is able to self-heal small punctures or slits so that foam materials on an inner side of the panel are prevented from passing through the holes or slits. The frame is stronger relative to the opening due to a reinforcing element applied to the inside perimeter of the opening on the underside of the trim element. | 1 |
RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 10/249,821, filed May 9, 2003, U.S. Pat. No. 6,809,024.
FIELD OF THE INVENTION
The present invention relates generally to a bipolar transistor and, more particularly, to a method for forming a bipolar transistor with a raised extrinsic base in an integrated bipolar and complementary metal oxide semiconductor (BiCMOS) transistor circuit.
BACKGROUND OF THE INVENTION
Bipolar transistors are electronic devices with two p-n junctions that are in close proximity to each other. A typical bipolar transistor has three device regions: an emitter, a collector, and a base disposed between the emitter and the collector. Ideally, the two p-n junctions, i.e., the emitter-base and collector-base junctions, are in a single layer of semiconductor material separated by a specific distance. Modulation of the current flow in one p-n junction by changing the bias of the nearby junction is called “bipolar-transistor action.”
If the emitter and collector are doped n-type and the base is doped p-type, the device is an “npn” transistor. Alternatively, if the opposite doping configuration is used, the device is a “pnp” transistor. Because the mobility of minority carriers, i.e., electrons, in the base region of npn transistors is higher than that of holes in the base of pnp transistors, higher-frequency operation and higher-speed performances can be obtained with npn transistor devices. Therefore, npn transistors comprise the majority of bipolar transistors used to build integrated circuits.
As the vertical dimensions of the bipolar transistor are scaled more and more, serious device operational limitations have been encountered. One actively studied approach to overcome these limitations is to build transistors with emitter materials whose band gaps are larger than the band gaps of the material used in the base. Such structures are called heterojunction transistors.
Heterostructures comprising heterojunctions can be used for both majority carrier and minority carrier devices. Among majority carrier devices, heterojunction bipolar transistors (HBTs) in which the emitter is formed of silicon (Si) and the base of a silicon-germanium (SiGe) alloy have recently been developed. The SiGe alloy (often expressed simply as silicon-germanium) is narrower in band gap than silicon.
The advanced silicon-germanium bipolar and complementary metal oxide semiconductor (BiCMOS) technology uses a SiGe base in the heterojunction bipolar transistor. In the high-frequency (such as multi-GHz) regime, conventional compound semiconductors such as GaAs and InP currently dominate the market for high-speed wired and wireless communications. SiGe BiCMOS promises not only a comparable performance to GaAs in devices such as power amplifiers, but also a substantial cost reduction due to the integration of heterojunction bipolar transistors with standard CMOS, yielding the so-called “system on a chip.”
For high-performance HBT fabrication, yielding SiGe/Si HBTs, a conventional way to reduce the base resistance is through ion implantation into the extrinsic base. The ion implantation will cause damage, however, to the base region. Such damage may ultimately lead to degradation in device performance.
To avoid the implantation damage, a raised extrinsic base (Rext) is formed by depositing an extra layer of polycrystalline silicon (or SiGe) atop the conventional SiGe extrinsic base layer. There are essentially two processes that may be utilized to achieve such a raised extrinsic base. The first process involves selective epitaxy; the other involves chemical-mechanical polishing (CMP).
In a typical selective epitaxy process, the raised extrinsic base polycrystalline silicon is formed before the deposition of the intrinsic base SiGe. The intrinsic base SiGe is deposited selectively onto the exposed surface of silicon and polycrystalline silicon inside an over-hanging cavity structure. The selective epitaxy with a cavity structure mandates stringent process requirements for good selectivity, and suffers from poor process control. U.S. Pat. No. 5,523,606 to Yamazaki and U.S. Pat. No. 5,620,908 to Inoh, et al. are some examples of prior art selective epitaxy processes.
As mentioned above, CMP can be applied to form a raised extrinsic base. U.S. Pat. No. 5,015,594 to Chu et al. discloses the formation of extrinsic base polysilicon by CMP. The isolation, which is achieved by thermal oxidation, is not feasible in high performance devices due to the high temperature thermal process.
U.S. Pat. No. 6,492,238 to Ahlgren, et al. provides a self-aligned process for forming a bipolar transistor with a raised extrinsic base, an emitter, and a collector integrated with a complementary metal oxide semiconductor (CMOS) circuit with a gate. An intermediate semiconductor structure is provided having a CMOS area and a bipolar area. An intrinsic base layer is provided in the bipolar area. A base oxide is formed across, and a sacrificial emitter stack of silicon layer is deposited on both the CMOS and bipolar areas. A photoresist is applied to protect the bipolar area and the structure is etched to remove the emitter stack silicon layer from the CMOS area only such that the top surface of the emitter stack silicon layer on the bipolar area is substantially flush with the top surface of the CMOS area. Finally, a polish stop layer is deposited having a substantially flat top surface across both the CMOS and bipolar areas suitable for subsequent chemical-mechanical polishing (CMP).
Despite being capable of forming an HBT having a raised extrinsic base, the self-aligned-CMP process disclosed in the '238 patent is complicated requiring many different processing steps to achieve the desired structure. As such, there still exists a need for providing a simple and reliable method for fabricating high-performance HBTs that have a raised extrinsic base.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a simple, yet reliable method of fabricating a high-performance HBT in an integrated BiCMOS process.
A further object of the present invention is to provide a method of fabricating a HBT having a raised extrinsic base.
A still further object of the present invention is to provide a method of fabricating a high-speed HBT having a raised extrinsic base in which unity current gain frequency fT and unity unilateral power gain frequency fmax can reach 200 GHz or greater.
A yet further object of the present invention is to provide a method of fabricating an npn transistor in a BiCMOS process flow.
A still yet other object of the present invention is to provide a method of fabricating a HBT in which the reliability of the transistor is improved by reducing the leakage between the emitter region and the base region.
These and other objects and advantages are achieved in the present invention by providing and utilizing a patterned emitter landing pad stack in a non-self-aligned process. The patterned emitter landing pad stack of the present invention comprises polySi and/or SiN located atop an oxide. In the case when a combination of polySi and SiN is employed, the polySi is located atop the SiN. The patterned emitter landing pad stack which is located atop the base region serves the following three functions in the present invention: First, the patterned emitter landing pad stack aides in improving the alignment for the emitter-opening lithography. Secondly, the patterned emitter landing pad stack acts as an etch stop layer for the emitter opening etch. Thirdly, non-removed portions of the patterned emitter landing pad stack at the end of the process provides isolation between the emitter region and the raised extrinsic base region, together with the isolation spacers to be described later.
One aspect of the present invention is directed to a method of fabricating a high-performance HBT having a raised extrinsic base which includes the steps of:
forming a patterned emitter landing pad stack atop portions of a base region, said patterned emitter landing pad stack comprising at least a bottom oxide; forming a doped semiconducting layer atop the patterned emitter landing pad stack as well as atop portions of the base region that does not contain said patterned emitter landing pad stack; forming a material stack atop the doped semiconducting layer; providing an emitter opening in portions of said material stack and said doped semiconducting layer stopping on an upper surface of said bottom oxide of said patterned emitter landing pad stack; removing portions of said bottom oxide of said patterned emitter landing pad exposing a portion of said base region; and forming an emitter in said opening.
In a preferred embodiment of the present invention, the exposed portions of the bottom oxide are removed utilizing an etching method such as a chemical oxide removal process in which minimal undercut or substantially no undercut is formed beneath the patterned emitter landing pad stack.
In the present invention, the base region includes a monocrystalline region that is surrounded on either side by adjoining polycrystalline regions. The monocrystalline region is formed atop a Si substrate, whereas the polycrystalline regions are located atop trench isolation regions that are located in the Si substrate. The raised extrinsic base of the present invention includes the doped semiconducting layer that is located above the polycrystalline regions of the base region. Because of the presence of a monocrystalline region in the base region, there is no interface formed between that portion of the base region and the intrinsic base that is formed under the emitter opening. As such, the link resistance between these two regions is very low in the HBT of the present invention.
Another aspect of the present invention relates to a structure which comprises
a base region having a monocrystalline region located atop a Si substrate and polycrystalline regions located atop trench isolation regions that are present in the Si substrate, with said monocrystalline region separating the polycrystalline regions; a raised extrinsic base located atop the polycrystalline regions of the structure and part of the monocrystalline region that does not contain a patterned emitter landing pad stack; an emitter opening located above said monocrystalline region, said emitter opening is defined by said patterned emitter landing pad stack; and an emitter region located in said emitter opening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-5 are pictorial representations (through cross sectional views) illustrating the basic processing steps that are employed in the present invention in forming a high-performance HBT.
FIGS. 6A-6B are pictorial representations showing an alternative embodiment of the present invention which occurs after the emitter opening has been formed.
DETAILED DESCRIPTION OF THE INVENTION
The present invention, which provides a method for fabricating a high-performance transistor in a BiCMOS process in which a patterned emitter landing pad stack is employed as well as the resultant structure that is formed from the inventive method, will now be described in greater detail by referring to the drawings that accompany the present application. The drawings of the present application are directed to the HBT device area. For clarity, the CMOS device area as well as other areas of a typically BiCMOS structure are not shown in the drawings of the present application.
FIG. 1 shows an initial structure of the present invention. The initial structure includes a Si substrate 10 having trench isolation regions 12 formed therein. The Si substrate 10 may be a Si-containing semiconductor structure such as Si, SiGe or a silicon-on-insulator. Alternatively, the Si substrate 10 may be a Si layer such as epi-Si or a:Si formed atop of a semiconductor substrate. The Si substrate 10 may include various doping or well regions formed therein. Moreover, the Si substrate 10 may include a subcollector region which connects the HBT device to an adjacent collector region.
The trench isolation regions 12 that are located in the Si substrate 10 are made using conventional techniques that are well known to those skilled in the art including, for example, lithography, etching, trench filling, and planarization. The trench fill material includes a dielectric such as a high-density oxide or tetraethylorthosilicate (TEOS).
The initial structure shown in FIG. 1 also includes base region 14 located atop the Si substrate 10 as well as the trench isolation regions 12 . The base region 14 is formed on exposed surfaces of the structure using a low temperature epitaxial growth process (typically 450 °-700° C.). The base region 14 , which may comprise Si, SiGe or a combination of Si and SiGe, is monocrystalline 16 on top of exposed portions of Si substrate 10 and polycrystalline 18 on top of trench isolation regions 12 . The region in which a change from monocrystalline to polycrystalline occurs is referred to in the art as the facet region. The base region 14 that is formed at this step of the present invention typically has a thickness after epitaxial growth of from about 200 to about 6000 A. It is noted that monocrystalline region 16 is thicker than the polycrystalline regions 18 .
Next, an oxide layer is formed atop the base region 14 using either an oxidation process or a conventional deposition process such as plasma-enhanced chemical vapor deposition (PECVD). The oxide layer, which serves as the bottom layer of the emitter landing pad, has a thickness of from about 5 to about 50 nm. Next, a layer of polySi and/or SiN, which serves as the top layer of the emitter landing pad, is formed atop the oxide layer utilizing a conventional deposition process such as CVD, PECVD, atomic layer deposition, chemical solution deposition, sputtering or evaporation. In embodiments in which a combination of polySi and SiN is employed, the polySi is located atop the SiN. Alternatively, and when the top layer of emitter landing pad is comprised of SiN, a thermal nitridation process may be used in forming the SiN layer. The layer of polySi and/or SiN has a thickness of from about 5 to about 200 nm.
The oxide and polySi and/or SiN layer are then patterned by lithography and etching to provide a patterned emitter pad stack 20 which includes bottom oxide layer 22 and top polySi and/or SiN layer 24 . Note that the patterned emitter landing pad stack 20 is located atop the monocrystalline region 16 .
Following formation of the patterned emitter landing pad stack 20 atop the monocrystalline portion of the base region 14 , a doped semiconducting layer 26 such as polysilicon, Si or SiGe (hereinafter doped layer 26 ) is formed on the patterned emitter landing pad stack 20 as well as atop portions of the base region 14 that do not contain the patterned emitter landing pad stack. The doped layer 26 can be a layer with a variable doping concentration, or Ge composition that can be grown in a state-of-the-art low temperature epitaxy system. The resultant structure is shown, for example, in FIG. 2 . The doped layer 26 may also be formed by either an in-situ doped deposition process or by first depositing a polysilicon, Si or SiGe layer and then doping by ion implantation and annealing. In a preferred embodiment of the present invention, an in-situ doping deposition process is utilized. The doped layer 26 typically has a thickness from about 20 to about 400 nm.
It is noted that the portions of doped layer 26 that are located above the polycrystalline regions 18 of base region 14 form the raised extrinsic base of the inventive HBT. It is noted that doped layer 26 may have polycrystalline portions 26 a and 26 c and monocrystalline portions 26 b . The polycrystalline portions 26 a are located atop the polycrystalline portions 18 in base region 14 . The polycrystalline portion 26 c is located above the patterned emitter landing pad stack. The monocrystalline portion 26 b is located atop monocrystalline region 16 of base region 14 that does not include the patterned emitter landing pad stack.
Following formation of the doped layer 26 , a material stack 28 (see FIG. 2 ) comprising a bottom dielectric isolation layer 30 and an optional top polysi layer 32 is formed atop the doped layer 26 . The bottom dielectric isolation layer may be comprised of any dielectric material including, for example, an oxide or nitride. It is noted that the top polysi layer 32 is optional therefore it may be omitted from the method of the present invention; the remaining drawings omit top polysi layer 32 . The bottom dielectric isolation layer 30 is employed in the present invention to isolate the base from the emitter, while the top polySi layer 32 is employed in the present invention to protect the dielectric isolation layer. The material stack 28 is formed by first depositing or thermally growing the dielectric isolation layer 30 having a thickness of from about 10 to about 400 nm. After formation of the dielectric isolation layer 30 , the optional polySi layer 32 having a thickness of from about 5 to about 300 nm may be formed by deposition.
A photoresist mask 34 having an opening 36 (see FIG. 2 ) is formed atop the material stack 28 by conventional lithography which includes applying a photoresist atop the material stack 28 , exposing the photoresist to a pattern of radiation and developing the pattern into the photoresist by utilizing a conventional developer solution. The opening 36 in the photoresist mask 34 defines the emitter opening in the structure which will be formed in a subsequent step.
FIG. 3 shows the resultant structure after performing an etching step and removing the photoresist mask 34 . Note that the etching step forms emitter opening 38 which extends from the upper surface of optional polySi layer 32 (if present), through dielectric isolation layer 30 , doped layer 26 and polySi and/or SiN layer 24 stopping atop oxide layer 22 of patterned emitter landing pad 20 . The etching is performed utilizing one or more etching steps in which dry etching such as reactive-ion etching (RIE), wet etching or a combination thereof is employed. As is shown in FIG. 3 , the photoresist mask 34 is typically removed after the etching process.
An emitter region is then formed in the emitter opening 38 . In one embodiment of the present invention, the emitter region is formed by first providing an insulating spacer 40 on each sidewall of the emitter opening 38 . In this embodiment of the present invention, the insulating spacers 40 are comprised of a nitride or oxynitride and they are located atop the pad oxide layer 22 . The insulating spacers 40 are formed by deposition followed by an etching step. Next, the exposed oxide layer 22 in the emitter opening 38 is removed from the structure providing the structure shown, for example, in FIG. 4 . Note that the removing step exposes a surface portion of the underlying base region 14 . In particular, the monocrystalline region 16 is exposed.
The exposed portions of oxide layer 22 are removed utilizing a chemical oxide removal (COR) process or similar process that induces minimal undercut or substantially no undercut of the patterned emitter landing pad stack. In the COR process, a gaseous mixture of HF and ammonia is employed. The ratio of HF to ammonia employed in the COR process is typically from 1:10 to 10:1, with a ratio of 2:1 being more highly preferred. Moreover, the COR process employed in the present invention is performed at a pressure between about 1 mTorr to about 100 mTorr and at a temperature of about 25° C. As is depicted in FIG. 4 , the COR process provides minimal or substantially no undercut region beneath the insulating spacers 40 .
After the COR process, an emitter polysilicon 42 is deposited and patterned providing the structure shown, for example, in FIG. 5 . The emitter polysilicon is a doped polysilicon material that can be formed utilizing an in-situ doping deposition process or deposition, followed by ion implantation and annealing. Note that the emitter polysilicon is in contact with the monocrystalline portion 16 of the base layer 14 . It is should be noted that the doping of the emitter polysilicon 42 , the base 14 and the collector can be tailored to provide either an npn or a pnp HBT, with preference given herein to npn HBT transistors.
FIGS. 6A-6B show another embodiment of the present invention. In this embodiment of the present invention, the processing steps employed in fabricating the structure shown in FIG. 3 are first performed. Next, oxide or oxynitride 50 is formed on the sidewalls of the emitter opening by a thermal oxidation process, with or without additional active nitrogen sources. Following oxide 50 formation, insulating spacers 40 are formed on the sidewalls of oxide 50 as well as atop surface portions of oxide layer 22 . The insulating spacers are formed as described above. FIG. 6A shows the HBT structure including oxide layer 50 and insulating spacers 40 . FIG. 6B shows the structure that is formed after etching of pad oxide layer 22 and depositing and etching the emitter polysilicon 42 .
The method and structure of the present invention improve isolation between the emitter and the raised extrinsic base.
While the present invention has been particularly shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present invention. It is therefore intended that the present invention not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims. | A method of forming a quasi-self-aligned heterojunction bipolar transistor (HBT) that exhibits high-performance is provided. The method includes the use of a patterned emitter landing pad stack which serves to improve the alignment for the emitter-opening lithography and as an etch stop layer for the emitter opening etch. The present invention also provides an HBT that includes a raised extrinsic base having monocrystalline regions located beneath the emitter landing pad stack. | 7 |
This application is a continuation of application Ser. No. 07/533,857, filed Jun. 6, 1990, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a tool for applying a ferrule to a lock wire passing through a plurality of threaded fasteners to prevent the unintentional unthreading of such fasteners.
In rotating machinery having close tolerances between rotating and stationary elements, such as turbines, it is imperative that all objects, no matter how small, be kept from contact with the rotating elements of the machinery. The presence of any foreign object could result in the catastrophic failure of the entire machine.
Such machinery is inherently complex and requires many nuts, bolts, screws and other threaded fasteners to assemble all of its components. Since the operation of such machinery may involve very high rotating speeds, which may induce vibrations into the machine elements, it is necessary to provide some means for preventing the inadvertent unthreading of the numerous threaded fasteners.
It is known to apply lock wires to threaded fasteners to prevent their inadverent unthreading. Typically, the lock wire passes through a transverse hole in at least two threaded fasteners and is twisted back on itself in alternating clockwise and counterclockwise directions between the threaded fasteners. The process is duplicated between additional threaded fasteners until the entire threaded fastener pattern has been wired. Following the required stringing and twisting, the lock wire is cut and bent into a certain position.
While the known lock wire technique has provided satisfactory results, it requires a very time consuming and laborious application process. Often the final result is unsatisfactory due to variations in the quantity and tautness of the twists, and the variations in the tension of the lock wire. It has been estimated that annual losses of approximately $10,000,000 are incurred just from re-working unacceptable lock wire assemblies.
SUMMARY OF THE INVENTION
The present invention relates to a device for automatically inserting a ferrule over the safety cable, tensioning the wire crimping the ferrule onto the safety cable, and cutting off the excess cable.
The apparatus is used with a safety cable having a ferrule applied to one end and which is placed through a plurality of threaded fasteners in the pattern. A free end is inserted through a ferrule (held in the apparatus) and clamped onto a tension cylinder. Movement of the tension cylinder exerts a predetermined tension on the safety cable. The device then crimps the ferrule onto the safety cable to retain the safety cable in place at the desired tension. The end of the safety cable extending beyond the attached ferrule is cut off automatically by the tool to complete the process.
The device eliminates the necessity of hand twisting the lock wire and the problems associated with this technique.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a safety cable applied with the known techniques.
FIG. 2 is a plan view of a safety cable wire applied using the apparatus according to the present invention.
FIG. 3 is a side elevational view of the apparatus according to the present invention.
FIG. 4 is a partial, longitudinal cross-sectional view of the apparatus shown in FIG. 3.
FIG. 5 is a partial cross-sectional view of the crimping head of the apparatus according to the present invention taken along the V--V in FIG. 4.
FIG. 6 is a rear view of the wire gripping device used with the present invention.
FIG. 7 is a front view of the wire gripping device shown in FIG. 6.
FIG. 8 is a rear view of a tension cylinder plate used in conjunction with the present invention.
FIG. 9 is a front view of the tension cylinder plate shown in FIG. 8.
FIG. 10 is a side view of the ferrule crimping piston used with the apparatus according to the present invention.
FIG. 11 is a partial, transverse, cross-sectional view illustrating the ferrule crimping piston retainer used with the present invention.
FIG. 12 is a longitudinal, cross-sectional view of the valve assembly used with the apparatus according to the present invention.
FIG. 13 is a schematic diagram illustrating the fluid flow when the valve is in a first position.
FIG. 14 is a schematic diagram illustrating the fluid flow when the valve is in a second position.
FIG. 15 is a side view of the apparatus according to the present invention applying a ferrule to a safety cable.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A lock wire applied by known techniques is illustrated in FIG. 1 wherein threaded fasteners 10, 12 and 14 are engaged with a portion 16 of a rotating apparatus (not otherwise shown). The lock wire 18 comprising two strands 18a and 18b twisted together at one end are separated such that strand 18a passes through a transverse opening in fastener 10 while strand 18b passes around the exterior of the fastener 10. The strands are twisted together on the opposite side of fastener 10 and pass through a transverse opening formed in fastener 12. The lock wire 18 continues until the last fastener, in this particular instance fastener 14, whereupon one strand passes through a transverse opening in the fastener, while the other strand passes around and contacts the exterior of the fastener. The strands are twisted together on the opposite side of the fastener 14.
FIG. 2 illustrates a safety cable system applied using the apparatus according to the present invention. Threaded fasteners 10, 12 and 14 are once again engaged with the machinery portion 16. Lock wire 20 comprises a multi strand cable having a ferrule 22 affixed to end 20a. Safety cable 20 passes through transverse openings formed in the threaded fasteners 10, 12 and 14 until ferrule 22 bears against one side of fastener 10. At this point, ferrule 24 is inserted over the end of cable 20 against the side of fastener 14, a tension is applied to the safety cable 20 and the ferrule 24 is crimped onto the safety cable such that it bears against a side of the fastener 14. Safety cable 20 is then automatically trimmed. The pre-determined is tension is maintained in safety cable 20 by the contact of ferrules 22 and 24 with the sides of the threaded fasteners 10 and 14, respectively.
The device for applying tension to the safety cable and applying the ferrule can be seen best in FIG. 3 and comprises a tension cylinder 26, a valve assembly 28 and a tension piston 30 slidably mounted in the tension cylinder and having a portion extending exteriorly of the tension cylinder 26 upon which is mounted wire gripper 32. Outer tube 34 extends generally concentrically through the tension cylinder 26 and the tension piston 30, and has crimping head 36 attached to its distal end. Fitting 38 attaches the valve assembly 28 to a source of pressurized fluid, while valve actuator button 40 actuates the valve of the valve assembly 28.
Although the tool according to the present invention has been successfully operated and will be described as using compressed air as the pressurized fluid, it is to be understood that other pressurized fluids may be utilized without exceeding the scope of this invention.
A longitudinal cross-sectional view of the tension cylinder 26, the tension piston 30, the outer tube 34 and the crimping head 36 is illustrated in FIG. 4. As can be seen, tension piston 30 is slidably mounted within tension cylinder 26. Tension piston 30 has a piston portion with a first face 30a and a second face 30b located on opposite sides, as well as a portion which extends exteriorly of the tension cylinder 26.
Wire gripper 32 is fixedly attached to the exterior end of the tension piston 30. As illustrated in FIGS. 6 and 7, wire gripper 32 defines an opening 42 which slidably accommodates the end of the tension piston 30. The wire gripper 32 may be fixedly attached to the tension piston 30 by set screw 44 or similar means. Wire gripper 32 defines a longitudinally extending slot 46 passing inwardly from one side and has mounted on its rear portion, a gripper plate 48 such that a portion of gripper plate 48 extends over the rear of the slot 46. An edge 48a of the plate 48 is tapered with respect to the sides of the slot 46 such that a safety cable inserted into the slot 46 from the open side and urged toward the center of the gripper 32 will be gripped by the edge 48a of the plate 48.
A guide tube 50 is concentrically arranged within the outer tube 34, tension cylinder 26 and the tension piston 30, and extends substantially from the rear portion of the tension cylinder 26 to the gripping head 36. Guide tube 50, which may be formed of brass or similar material, slidingly receives crimping piston 52 in its interior. The dimensions of the exterior of crimping piston 52 and the interior of guide tube 50 are such that crimping piston 52 will readily slide within the guide tube, but will not allow the passage of a significant amounts of pressurized air between them. It may also be possible to use a seal attached to the crimping piston 52 to slidably seal against the inner surface of guide tube 50.
Guide tube 50 is also concentrically arranged within outer tube 34 so as to define an annular space there between. This annular space communicates with a first passage 54 defined by the tension cyliner 26 as illustrated in FIG. 24. Passageway 54 also provides communication with the interior of the tension cylinder 26 such that pressurized air passing through this passage 54 will act on first fact 30a of tension piston 30. Since passage 54 also communicates with the annular space between outer tube 34 and guide tube 50, pressurized air will also enter this space and communicate with the interior of the guide tube 50 via a plurality of holes 56 formed near the cutting head end of guide tube 50. Pressurized air passing through passage 54, and the annular space, holes 56 and the interior of guide tube 50 will act on a first end 52a of the crimping piston 52.
Tension cylinder 26 defines a second passage 58 which communicates with the interior of tension cylinder 26 such that pressurized air passing through passage 58 will act on the second face 30b of tension piston 30. As also illustrated in FIG. 4, second passage 58 communicates with the interior of the guide tube 50 via slot 64, so that any pressurized fluid within this passage will also act on the second end 52b of crimping piston 52.
FIGS. 8 and 9 illustrate rear and front views of a tension cylinder end plate 60, the cross-sectional side view of which is illustrated in FIG. 4. FIG. 8 illustrates the rear view end plate 60 (when viewed in the direction or arrow 62 in FIG. 4), while FIG. 9 illustrates the opposite or front side of the end plate. AS seen in FIG. 9, the front face of end plate 60 defines a slot 64 which facilitates communication between the passage 58 and the interior of guide tube 50. The front face also defines an opening 66 which communicates with passage 54. On the opposite, or rear, side of end plate 60, opening 68 communicates with slot 64, while opening 66 communicates with slot 70.
Valve assembly 28 attaches to the end of the tension cylinder 26 and the end plate 60, as illustrated in FIG. 3. Valve assembly 28 is shown in detail in FIG. 12 and comprises a valve housing defining outlet ports 72 and 74 which communicate with openings 68 and slot 70 formed in the rear or end plate 60, respectively. A generally vertically oriented spool assembly 75 is slidably mounted in valve assembly 28, such that pressurized fluid inlet port 76, which is attached to a source of pressurized air via fitting 38, selectively communicates with either outlet port 72 or outlet port 74. Ports 78 and 80 also formed as part of the valve housing serve as return vents and may be open to atmospheric pressure.
Valve assembly 75 may comprise a spool valve having lands 82 and 84 sealingly slidable against the inner surface of opening 86 formed in the valve housing. Spring 88 bears against the lower land 84 so as to urge the valve assembly 85 upwardly to the position shown in FIG. 12. In this first or normal position, the pressurized air inlet 76 communicates with outlet port 74 while port 72 is vented through port 78. When the valve assembly 75 is pushed downwardly via actuator button 40, land 82 will prevent fluid communication between inlet port 76 and outlet port 74. This movement will also move land 84 downwardly so as to allow communication between the inlet port 76 and the outlet port 72. In this downward position, outlet port 74 will then be vented through port 80.
As can be seen in FIGS. 4 and 5, crimping head 36 defines a generally triangularly shaped opening 90 which may extend only partially through the height of the crimping head 36. Opening 92 extends from the bottom of opening 90 to the opposite side of the crimping head 36 to facilitate the passage therethrough of the lock wire.
A crimping punch 94 is operatively associated with the crimping head 36 and extends through the crimping head 36 such that an end portion 94a extends into the opening 90. An opposite end of the crimping punch 94 extends into the interior of the guide tube 50. The crimping punch 94 is readily slidable within the guide tube 50 as well as the crimping head 36 such that the impact force exerted on the crimping panel 94 by the crimping piston 52 will push the crimping punch 94 into a ferrule held in opening 90 with sufficient force to permanently deform the ferrule and attach it to a safety cable.
The crimping punch 94 also serves as a means to hold a ferrule in the opening 90 with sufficient frictional, non-deforming force to enable the tool to be manipulated into any position without the ferrule falling out of the opening 90. When ferrule 96, illustrated in dotted lines in FIGS. 4 and 5, is manually inserted into the opening 90, it bears against end portion 94a of the crimping punch 94 such that the crimping punch 94 is urged slightly attached to the shank of the crimping punch 94 is moved in resilient contact with the end of the crimping head 36. Resilient sleeve 98 resiliently urges crimping punch 94 towards the left, as viewed in FIGS. 4 and 5, with sufficient force to hold the ferrule 96 within the opening 90, but with a force insufficient to cause any deformation of the ferrule. Thus, the ferrule is frictionally retained between the end 94a of the crimping punch 94 and the two side walls of the generally triangularly shaped opening 90.
The tool according to the invention also provides means to retain the crimping piston 52 in a retracted position displaced away from crimping punch 94. This position is generally indicated in FIG. 4 and is toward the rear end of the tension cylinder 26. As illustrated in this figure as well as in FIG. 10, crimping piston 52 defines an annular groove 52c extending around its periphery near second end 52b. Groove 52c is adapted to be engaged by a plurality of screw retainers 100 that extend through the wall of the rear portion of tension cylinder 26. One of these screw retainers is illustrated in FIG. 11 and comprises a threaded shank portion that is threadingly engaged with a wall of the tension cylinder 26 and a slotted head portion accessible from the exterior of tension cylinder 26 so that the radial position of the screw retainer may be readily adjusted merely by threading and unthreading its relative to the tension cylinder 26. The radial inner end portion of the screw retainer element 100 has a spring biased ball 102 that is biased in a radially inward direction, as viewed in FIG. 11, but which may be radially displaced in an outward direction. As is well known in the art, these retaining elements may be radially positioned within the tension cylinder 26 such that the end with the ball 102 extends through the guide tube 50 into the interior of the guide tube 50. When balls 102 engage groove 52c, the crimping piston 52 is retained in its retracted position. As will be described in more detail hereinafter, the fluid pressure acting on the rear portion 52b will initially be insufficient to overcome the retaining force exerted on crimping piston 52 by the screw retainer 100. However, when the pressure acting on end 52b reaches a predetermined value, it overcomes the retaining force and forces the crimping piston 52 along guide tube 50 into contact with the crimping punch 94 with sufficient force to deform the ferrule 96 and lock it onto the lock wire.
The operation of the tool will now be described with particular reference to FIGS. 13, 14 and 15. As illustrated in FIG. 13, when valve element 75 is in its normal position, inlet port 76, which is connected to a source of pressurized fluid 104 communicates with outlet port 74. This applies pressurized air to passage 54 through slot 70 and opening 66 such that the pressurized fluid acts on side 30a of tension piston 30, thereby urging the tension piston 30 toward the left as viewed in FIGS. 13 and 4 until tension piston 30 reaches an extreme position. The fluid pressure also acts on the first end 52a of the crimping piston 52 to urge it toward the right, as viewed in FIGS. 4 and 13 with sufficient force such that groove 52c will be engaged by the balls 102 of the locking elements 100. The air within the interior of guide tube 50 on the opposite side of piston 52 as well as in tension cylinder 26 on the opposite side of tension piston 30 will be vented to atmosphere via passage 58, slot 64, opening 68 and valve ports 72 and 78.
When tension cylinder 30 reaches its most extreme extended position and crimping piston 52 is retained in its retracted position, as illustrated in FIG. 4, the tool is ready for use. A ferrule is manually inserted into opening 90 and, as previously discussed, is retained therein by frictional contact with crimping punch 94. The tool may be manipulated such that lock wire 20 passes through the ferrule, retained in opening 90, and opening 92, as illustrated in FIG. 15. After the safety cable 20 has been inserted through the ferrule and the opening 92, the distal end is placed into and gripped by wire gripper 32. The tool is then positioned such that the gripping head 36 is against the side of the fastener 14 and valve actuator button 40 is manually depressed. This moves the lands 82 and 84 to the positions shown in FIG. 14. Thus, pressurized air inlet 76 now communicates with passage 58 through valve outlet port 72 opening 68 and slot 64. The pressurized air acts on face 30b of tension piston 30 to urge it toward the light as viewed in FIGS. 4 and 14.
Pressurized air also acts on the second end 52b of crimping piston 52. However, the retaining elements 100 are now engaged with the groove 52c and prevent any movement of crimping piston 52. Movement of tension piston 30 continues until the wire 20 has been tensioned to a predetermined amount. At this time movement of the tension piston 30 ceases thereby causing the pressure acting on end 52b of the crimping piston 52 to increase. This increase in pressure subjects the crimping piston 52 to forces sufficient to overcome the retaining elements 100, thereby urging crimping piston 52 rapidly toward the left, as illustrated in FIGS. 4 and 14 through guide tube 50 and into contact with the crimping punch 94. The impact between the crimping piston 52 and the crimping punch 94 is such that crimping punch 94 deforms the ferrule 96 and locks it onto the lock wire 20.
Once the crimping operation has been completed, the push button 40 is released thereby returning the lands 82 and 84 to their positions shown in FIG. 13. This allows the pressurized air to return the crimping piston 52 to its retracted position and to also move the tension piston 30 to its initial, extended position. The safety cable extending between the opening 92 and the wire gripper 32 may then be cut off and the tool removed. The frictional force exerted on the ferrule by the crimping punch 94 is insufficient to dislodge it from the safety cable after it has been crimped. Once the tool had been removed, the tension piston 30 and the crimping piston 52 are in their positions ready for a subsequent crimping operation.
While the wire gripper 32 has been shown to be oriented such that it grips a wire after having passed through the ferrule, it should be understood that both the wire gripper 32 as well as the tension piston 30 may be rotated about the longitudinal axis of the tool so as to achieve any desired orientation of the wire gripper. Then length and size of the crimping head and the outer tube may be made to any dimension so as to facilitate the application of ferrules and lock wires to positions that were heretofore rendered inaccessible by known lock wire techniques.
The foregoing description is provided for illustrative purposes only and should not be construed as in any way limited this invention, the scope of which is defined solely by the appended claims. | A device is disclosed for automatically inserting a ferrule over a safety cable, tensioning the cable and crimping the ferrule onto the safety cable, and cutting off excess cable. The apparatus is used with a safety cable having a ferrule applied to one end and which is placed through a plurality of threaded fasteners in a pattern. A free end is inserted through a ferrule held in the device and gripped by a tension cylinder. Movement of the tension cylinder exerts a predetermined tension on the safety cable. The device then crimps the ferrule onto the safety cable to retain the safety cable in place at the desired tension. The end of the safety cable extending beyond the attached ferrule is automatically cut off to complete the process. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). [62/321,946] filed in American United States Apr. 13, 2016, the entire contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a pharmaceutical composition for treating cerebral atrophy associated disease.
BACKGROUND OF THE INVENTION
[0003] Alzheimer's Disease, also known as senile dementia disease, has become a global epidemic as the aging population increases rapidly. According to the International Association dementia statistics, there are 46.8 million global dementia patients in 2015, and one person suffering from dementia disease every 3 seconds. It is expected the global dementia patients will be twice in 2030, thus, how to prevent and treat dementia disease is an important issue.
[0004] Dementia disease is a chronic, progressive degenerative disease, can be divided into two categories: degenerative dementia and vascular dementia disease. The majority of patients are degenerative dementia, wherein the Alzheimer's disease, frontotemporal lobe degeneration, and Dementia with Lewy Bodies are the most common disease.
[0005] Vascular dementia disease is caused by stroke or cerebral vascular disease, the mental retardation is also caused by brain cell death due to poor blood circulation in the brain. Symptoms of early dementia may include: irritability, aggression, inability to normal speech, easy to get lost, emotional instability, loss of motivation to survive, loss of long-term memory, difficult to remember the recent occurrence, difficult to take care of themselves and behavioral abnormalities. Therefore, when the patient's condition deteriorates, they often begin to leave the family and social relations, and the gradual loss of physical function, then leading to death.
[0006] In the current study of dementia prevention is mainly focus on Alzheimer's disease. Although the true cause of Alzheimer's disease is still unknown, the abnormal accumulation of beta-amyloid, neurofibrillary tangles, and extensive neuro-inflammation, are the main pathological features, and so as cause serious impact on nerve repair and regeneration function.
[0007] The current treatment of dementia, mainly using acetylcholine inhibitor (acetyl-cholinesterase inhibitor) or NMDA receptor antagonist (NMDA anatagonist) to delay the development of the disease or improve the patient's mental and behavioral symptoms. However, the drugs cannot effectively prevent or restore damaged brain cells, in addition, the above-mentioned drugs on the patients themselves have convulsions, dyspnea and other side effects. Therefore, there is still a need for better medical treatment to treat the dementia disease.
SUMMARY OF THE INVENTION
[0008] Accordingly, the present invention provides a pharmaceutical composition for treating cerebral atrophy associated disease. Said pharmaceutical composition comprising adipose-derived stem cells, can improve the function of excitatory synapses in dementia patients and improve the function of memory storage area in brain.
[0009] The present invention provides a method for treating cerebral atrophy associated disease in a subject, wherein the method comprising administering to said subject a pharmaceutical composition, wherein the pharmaceutical composition is having an adipose-derived stem cell.
[0010] In one embodiment, the treating cerebral atrophy associated disease is through improving the function of memory storage area in brain of dementia patients.
[0011] In one embodiment, the treating cerebral atrophy associated disease is through increasing the function of excitatory synapses in dementia patients.
[0012] In one embodiment, the treating cerebral atrophy associated disease is through increasing the numbers of pyramidal neuron synapses in the cerebral prefrontal cortex in dementia patients.
[0013] In one embodiment, the treating cerebral atrophy associated disease is through increasing the numbers of pyramidal neuron synapses in the hippocampus in dementia patients.
[0014] In one embodiment, the concentration of the adipose-derived stem cells is 6×10 4 /ul˜7×10 4 /ul.
[0015] In one embodiment, the pharmaceutical composition is implanted near the fornix area in right cerebral hemisphere, wherein AP is −0.2, ML is −0.5 and DV is −6.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A shows the histochemistry stain of brain slices in control group and dementia group, in comparison with control group the histochemistry stain is darker in dementia group.
[0017] FIG. 1B shows the amyloid β-protein expressions of control group and dementia group, in comparison with control group the amyloid β-protein expression is higher in dementia group.
[0018] FIG. 2A shows the histochemistry stain of brain slices in the experimental group in day 3, wherein the blue fluorescence is DAPI and the yellow fluorescence is Anti-Human nuclei antigen (MAB1281).
[0019] FIG. 2B shows the histochemistry stain of day 14 brain slices in the experimental group, wherein the blue fluorescence is DAPI and the yellow fluorescence is Anti-Human nuclei antigen (MAB1281)
[0020] FIG. 3 shows the spatial memory learning analysis of rats in all group, wherein the points in the figures represent the escaping time from water maze, the longer time represents the worse memory function; wherein the memory function of rats in the experimental group is improved as similar as rats in the control group, and is significantly different with the rats in dementia group (the rats in dementia group are having worse memory function) in day 5.
[0021] FIG. 4 shows the test result of excitatory synapses function of rats in all groups; as shown in the figure, the glutamatergic postsynaptic expression of rats in dementia group is significantly lower than the rats in control group; however, the glutamatergic postsynaptic expression of rats in experimental group is significantly higher than the rats in dementia group.
[0022] FIG. 5A shows four portions of medial prefrontal cortical pyramidal neurons of rats, which includes: proximal end of basal dendrite, distal end of basal dendrite, proximal end of apical dendrite and distal end of apical dendrite, calculating the numbers of neurons, wherein the proximal end means closer to neuron body.
[0023] FIG. 5B shows the statistic data of dendritic spine density of medial prefrontal cortical pyramidal neurons of rats, in comparison with control group, the numbers of dendritic spine in dementia group is decreased; however, the dendritic spine density of degenerated neurons in experimental group is increased significantly, which is similar to the dendritic spine density of degenerated neurons in control group
[0024] FIG. 6A shows the pictures of all portions of CA1 hippocampal pyramidal neurons, which is photographed by 10 μm from 2nd branch of distal end of basal dendrite near neuron body, and from the 3rd branch of apical dendrite near neuron body.
[0025] FIG. 6B shows the statistic data of dendritic spine density of CA1 hippocampal pyramidal neurons, wherein the in comparison with the control group, the numbers of dendritic spine in dementia group is decreased; however, the dendritic spine density of degenerated neurons in experimental group is increased significantly, which is similar to the dendritic spine density of degenerated neurons in control group
DETAILED DESCRIPTION OF THE INVENTION
[0026] Adipose-derived stein cells (ADSCs) of the present invention are mesenchymal stem cells (MSC) in adipose tissue, which can be obtained from liposuction or lipectomy. That means, it is easy and convenient to obtain the adipose-derived stem cells without causing trauma in patients. Besides, the adipose-derived stein cells can be autologous implanted, which is easily be compatible, so as to reduce the anti-rejection drugs, long-term in vitro culture and other shortcomings. Furthermore, the adipose-derived stem cells are easy to isolate and can be rapidly and stably amplified in vitro, and are also less susceptible to aging, thus being suitable for use as pharmaceutical compositions of the present invention.
[0027] Experimental Animals
[0028] The Wistar rats are divided into three groups: control group, dementia group and experimental group, 300 pmole Amyloid-β-protein is implanted daily into the rats in dementia group and experimental group in day 0-28, the implantment position is AP: 0.4, ML: 1.5, DV: 3.3 so as to cause dementia disease. The pharmaceutical composition of the present invention (containing 1×10 6 /15 ul adipose-derived stem cells, which is 6×10 4 /ul˜7×10 4 /ul adipose-derived stem cells) is implanted into the rat brain of experimental group in day 14, the implantment position is near the fornix area in right cerebral hemisphere (AP: −0.2, ML: −0.5, DV: −6) and the rat brain in control group is punctures in day 14.
Example 1. Amyloid β-Protein Staining
[0029] The rat brain of control group and dementia group is stained by anti-Aβ 1-42 antibody. Please refer to FIG. 1A-1B , the historical staining color of dementia group is darker than control group, therefore, the level of amyloid β-protein of dementia group is higher.
Example 2. Immunofluorescence Staining
[0030] The rats of experimental group is implanted with the pharmaceutical composition of the present invention, and then sacrificed in day 3 ( FIG. 2A ) and week 2 ( FIG. 2B ) respectively. The brain samples are stained by anti-Human nuclei antigen (MAB1281), the results are shown in FIG. 2A and FIG. 2B , wherein the blue fluorescence is DAPI and the yellow fluorescence is Anti-Human nuclei antigen (MAB1281).
[0031] In FIG. 2B , the Adipose-derived stem cells are survive in rat brain after the pharmaceutical composition implantment for 14 days, wherein the cell morphology is same as the cells in rat brain after the implantment for 3 days ( FIG. 2A ).
Example 3. Spatial Memory Test
[0032] The rats in control group, dementia group and experimental group were placed in a Morris water maze for 5 days to observe the movement patterns of rats in each group for the test of spatial memory. Please refer to FIG. 3 , the points represent the various groups of rats to escape the water maze of time, the longer time means the worse memory function. The results of the day 5 in the experimental group showed that the memory function of the experimental group was improved to be similar to the control group (50% to 60% improvement in the experimental group compared with the dementia group) and significantly different from the dementia group (dementia group are having worse memory function), it can be seen that the pharmaceutical composition of the present invention can improve the function of memory storage area in brain of dementia patients.
Example 4. Efficacy Test of Excitatory Synapses
[0033] The rat brain of control group, dementia group and experimental group rats were analyzed by Western-style dot-blot method using the antibody of synaptic density protein 95 (PSD-95). The level of glutamatergic postsynaptic in the brain of the rat is shown in FIG. 4 .
[0034] As shown in FIG. 4 , the level of glutamatergic postsynaptic in the dementia group was significantly decreased (80% to 90% in the dementia group compared with the control group). However, the level of rat brain glutamate acid synaptic (glutamatergic postsynaptic) in experimental group is higher than dementia group (50% to 60% higher in the experimental group compared with the dementia group). Therefore, the pharmaceutical composition of the present invention is effective to improve the function of excitatory synapses in dementia patients.
Example 5. Dendritic Spine Density Analysis
[0035] The neurons in the control group, dementia group and experimental group rats were labeled with Lucifer yellow to analyze the density of nerve dendrites in the brain of each group.
[0036] FIG. 5A shows the dendritic spine density of four portions of medial prefrontal cortical pyramidal neurons of rats, which includes: proximal end of basal dendrite, distal end of basal dendrite, proximal end of apical dendrite and distal end of apical dendrite, calculating the numbers of neurons, wherein the proximal end means closer to neuron body. The calculating method is to count the number of synapses, and then calculate the mean value within a distance of 10 μm in four representative regions of each group in the pictures. Statistical results as shown in FIG. 5B , the rats in dementia group had significantly lower nerve synapses compared with the control group (40% to 45% less in the dementia group than in the control group), whereas the experimental group showed the number of synapses in degenerative nerves increased significantly (the experimental group increased by 90% to 108% compared with the dementia group), and the number of synapses with the control group recovered to similar amount with control group. Therefore, the pharmaceutical composition of the present invention is effective to increasing the numbers of pyramidal neuron synapses in the cerebral prefrontal cortex in dementia patients.
[0037] FIG. 6A shows the pictures of all portions of CA1 hippocampal pyramidal neurons, which is photographed by 10 μm from 2nd branch of distal end of basal dendrite near neuron body, and from the 3rd branch of apical dendrite near neuron body. The number of synapses in the picture is counted, and then average was calculated.
[0038] Statistical results is shown in FIG. 6B , the dementia group had significantly lower neuronal synapses compared to the control group (30% to 40% reduction in the dementia group compared with the control group), whereas the experimental group showed degenerative nerves processes (Experimental group increased 70%˜80% compared with dementia group), and number of synapses is recovered to similar amount with control group, it can be seen that the pharmaceutical composition of the present invention can increase the numbers of pyramidal neuron synapses in the hippocampus in dementia patients.
[0039] From the above results, the pharmaceutical composition of the present invention can effectively increase the density of nerve dendrites of dementia patients.
[0040] Although the present invention has been described in terms of specific exemplary embodiments and examples, it will be appreciated that the embodiments disclosed herein are for illustrative purposes only and various modifications and alterations might be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims. | The present invention provides a pharmaceutical composition to treat cerebral atrophy associated disease. Said pharmaceutical composition comprising adipose-derived stem cells, can reverse the function of excitatory synapses in dementia patients and improve the function of memory storage area in brain. | 0 |
FIELD OF INVENTION
This invention relates to spring action footwear and more specifically to such footwear which amplify the stride of the user.
DESCRIPTION OF PRIOR ART
It has long been known, that when people walk, jog, or run, a significant percentage of their forward kinetic energy is wasted and lost. This loss results in shock which is caused by a person's foot impacting with the ground. How to store and release this energy loss is the overall problem. Existing embodiments usually involve an assemblage of springs adhered to the base of a shoe. Generally, the higher the assemblage elevates a user's foot above the ground, the more thrust imparted to the user. This fact leads to a problem with lateral stability. Generally, the higher a user's foot is elevated above the ground, the easier it will be for a user to twist an ankle. Coil springs are inherently unstable in a lateral direction causing unwanted sidesway, especially upon release. Devices that employ a group of coil springs arranged under a shoe generally lack adequate lateral stability and may pose a safety risk. An example of such a device is U.S. Pat. No. 4,660,299 to Omilusik (1987) which utilizes four vertically disposed coil springs adhered to the sole of a shoe. Since Omilusik mounts the four springs independently with one end free, the energy released from each can be misdirected and unsynchronized with it's neighbor.
A solution to the lateral stability problem is to add a guiding mechanism to the spring assembly. Embodiments of this type usually include two vertically spaced plates biased apart by the spring assembly. U.S. Pat. No. 4,912,859 (1989) to Ritts is an example of this type. Ritt arranges a grid of vertically disposed coil springs between two horizontal plates, elastically connecting the plates with a diagonal arrangement of broad flat cross bars. These cross bars stabilize the top plate against excessive sidesway or lateral instability while permitting vertical motion. The cross bars serve as the guiding mechanism, however, as the complexity of a device increases, so does the weight of the device. Generally, the greater the weight placed on a person's lower extremities, the less comfortable is a person's forward motion. A solution to the weight dilemma is to employ spring devices between the plates which are intrinsically, laterally stable thereby eliminating the need for an added guiding mechanism.
Many embodiments utilize a broad leaf spring to elastically connect the upper and lower plates. These constructions avoid the problems associated with coil springs and usually offer the advantage of a dual-spring action. A person's foot in natural forward motion undertakes three basic movements; a heel impact, followed by a rolling-over movement, and ending with a metatarsal thrust. Comfort to the wearer is increased when a device emulates these three natural movements in sequence. These devices attempt to emulate this natural motion. An example of this type of footwear is U.S. Pat. No. 4,534,124 (1985) by Schnell. Schnell relies on a broad leaf spring connected from the front or rear of the upper plate to the front or rear of the lower plate for primary energy storage. The diagonal leaf forms cavities in the heel and toe areas permitting alternate deflections to occur in those areas. Since this device employs only one spring to mimic the foot's three natural movements, the emulation is vague. Another disadvantage is the lack of adjustability. Because thrust is directly related to deflection, it is desirable to have a spring rate adjusted to approach maximum deflection, based on the users weight and velocity. To achieve this, the spring rates need to be adjustable. Other examples of leaf spring based footwear are; U.S. Pat. No. 4,360,978 (1982) by Simpkins, and U.S. Pat. No. 5,343,636 (1994) by Sabol.
Many other types of mechanisms have been proposed. There are devices that provide heel rebound only; such as, U.S. Pat. No. 4,894,934 (1990) by Illustrato, which confines the apparatus within a thin sole, and U.S. Pat. No. 5,282,325 (1994) by Beyl, who proposes heel rebound cartridges. U.S. Pat. No. 5,343,637 (1994) by Schindler offers a pair of heel and toe spiral leaf springs. All of these inventions lack either:
(a) sufficient deflection to provide ample thrust,
(b) emulation of a person's natural foot movements,
(c) lateral stability,
(d) spring rate adjustability, or
(e) low relative weight.
The solution to the overall problem involves the design of a unique group of components that directly correspond to the three essential elements of the foot's natural movements, while conforming to above listed specifications.
OBJECTS AND ADVANTAGES
A primary object of the present invention is to provide a spring-equipped sole construction capable of storing and releasing foot impact energy in a manner which closely resembles the natural movements of a person's foot in forward motion.
Another object is to provide a sole construction of the aforesaid nature having a stable, stride-amplifying effect.
An additional object is to provide a sole construction as in the foregoing object having user-adjustable internal spring assemblies.
A further object is to provide a lightweight sole construction that will overcome the shortcomings of the prior art devices.
A still further object is to provide a foot prosthesis of the aforesaid nature having an upper body resembling an upper foot, for pivotable attachment at the ankle area of an artificial leg.
Further objects and advantages will become apparent from a consideration of the drawings and ensuing descriptions.
Many previous embodiments employed groups of coil springs arranged under an article of footwear. Examples of this type are Omiluslk U.S. Pat. No. 4,660,299, and U.S. Pat. No. 4,457,0849. The primary problem with this type is that they permit unwanted lateral motion or sidesway. To remedy this problem, stabilizing mechanisms were added to stabilize the coils as seen in Ritt U.S. Pat. No. 4,912,859. The addition of more mechanisms unfortunately adds weight which is uncomfortable. Another large group of prior inventions utilize broad leaf springs, which are generally deployed diagonally between two horizontal plates, for primary energy storage. Examples of this type are Sabol U.S. Pat. No. 5,343,636, Simpkins U.S. Pat. No. 4,360,978, Schnell U.S. Pat. No. 4,534,124 and Whatley U.S. Pat. No. 5,060,401. Although this type provide a heel toe dual action, the emulation to a foot's three natural movements during footplant or contact with the ground is vague and uncomfortable. There are other attempts which offer various types of heel cartridges built within a sole such as Beyl U.S. Pat. No. 5,282,325, Illustrato U.S. Pat. No. 4,894,934 and Jacinto U.S. Pat. No. 4,592,153. The shortcomings with these are a general lack of thrust due to their constricted spring path or distance above the ground. Still other devices have employed groups of spiral leaf springs as seen in Schindler U.S. Pat. No. 5,343,637, or a large number of spring washers such as U.S. Pat. No. 4,267,648.
None of these stride amplifying devices accurately emulate the foot's natural movements during footplant while also offering dual adjustability, inherent lateral stability and low relative weight.
A BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective side view of an embodiment of the invention in position beneath an article of footwear. The often referred to longitudinal direction extends from the user's heel to toe, and the lateral direction extends from the user's right to left side.
FIG. 2 shows a perspective rear view of an embodiment of the invention in position beneath an article of footwear.
FIG. 3 shows an exploded view of the hinged leaf spring 30.
FIG. 4 shows a side elevation of the hinged leaf spring 30 in an uncompressed state.
FIG. 5 shows a side elevation of the hinged leaf spring 30 in a fully compressed state.
FIG. 6 shows a side elevation of the hinged leaf spring 30 at the onset of the roll-over phase with arrows 29, 31 depicting the area of central support.
FIG. 7 shows a perspective front view of an embodiment of the invention in position beneath an article of footwear.
FIG. 8 shows an exploded view of the x-shaped leaf spring 46.
FIG. 9 shows a perspective front view of the x-shaped leaf spring 46 in an uncompressed state.
FIG. 10 shows a perspective front view of the x-shaped leaf spring in a fully compressed state.
FIG. 11 shows a perspective side view of a second embodiment of the invention attached to the base of an artificial leg.
______________________________________Reference Numerals In Drawings______________________________________18 sole construction 20 shoe22 z-shaped platform 24 tab26 heel angled strip 27 hinge pin29 arrow, central support 30 hinged leaf spring31 arrow, central support 2 32 ringed elastics33 longitudinal shaft 34 top plate35 heel connection 36 diagonal plate37 toe connection 38 base plate40 non-skid covering 44 guide46 x-shaped leaf spring 47 angled strips48 posterior x-spring leaf 50 anterior x-spring leaf52 hinged leaf spring leaves 53 lower shaft54 upper end 55 rounded end apertures56 lower ends 57 curved end apertures58 upper cutouts 59 lower cutouts62 x-spring aperture 63 planar surface64 screw studs 66 lobe67 foot prosthesis 68 lobe aperture______________________________________
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and to FIG. 1 in particular, there is shown a sole construction 18 built in accordance with the invention, which is designed to be mounted on the base of a shoe 20. The sole construction 18 is comprised of a z-shaped platform 22, having a toe and heel area corresponding respectively, with a toe and heel area of the shoe. The platform is fabricated of lightweight, semi-flexible, resilient, material such as nylon, or the like, having a longitudinal cross sectional area resembling the letter z. The lateral direction extends from the user's right to left side, and the longitudinal direction extends from the user's heel to toe. The z-shaped frame is further comprised of a horizontally disposed top plate 34, spaced parallel to a base plate 38, and a coplanar diagonal plate 36. The top plate 34, whose outline resembles the sole of a shoe, is integrally connected, in the heel area, to the diagonal plate 36 forming a heel connection 35. The diagonal plate 36 extends downward toward the toe area where it is integrally connected to the base plate 38 forming a toe connection 37. These connections are spaced a distance from the longitudinal ends such that the heel area connection is laterally centered under the calcaneus or heel bone of a user, and the toe area connection is laterally centered under the metatarsals or forward foot bones of the user. The length and width of the platform being generally equivalent, respectively, to the length and width of the shoe. The height of the sole construction, as measured vertically from the base plate 38 to the top plate 34 inclusive, is generally equal to the width of the shoe. The lower surface of the base plate 38 is covered with a non-skid material 40 for improved adherence with the ground.
A hinged leaf spring 30 is positioned contiguously under, and parallel to, the heel connection of the z-shaped frame 22 as shown in FIG. 2. The hinged spring 30 is comprised of two rectangular, planar leaves 52 fabricated of a lightweight, rigid material, such as nylon. These leaves 52 are vertically oriented with upper ends 54 being rounded and lower ends 56 being outwardly curved as shown FIG. 3. The upper ends 54 also have alternate, interlocking cutouts 58 and an aperture 55 centered within the rounded end and extending laterally through each leaf. A hinge pin 27 extends through the aperture 55 and is pivotably secured by two tabs 24 which extend below the heel connection. The hinge pin 27 pivotably secures the upper ends 54 under the heel connection in the manner of a hinge. An angled strip 26 of resilient material such as spring steel, is juxtaposed contiguously to the upper ends 54. The angled strip 26 has a fixed end secured under the top plate 34 and a free end slidably engaged with the leaves. The lower ends 56 have opposing cutouts 59 and apertures 57 extending through laterally. A pair of shafts 53 extend through the apertures 56 and pivotably engage an outer ring of a group of ringed elastics 32. The ringed elastics 32 are comprised of three chain links with the outer links being rigid, and the inner link comprising a group of endless elastic bands.
An x-shaped leaf spring 46 having a lateral cross sectional area resembling the letter x, is sandwiched between the top plate 34 and the baseplate 38. The spring 46 is positioned such that its x-shaped cross section extends laterally across the toe area of the platform 22 as shown in FIG. 7. The x-shaped spring 46 is comprised of two s-shaped, interlocking leaves 48, 50, each having curved outer ends which are slidably engaged with the inner sides of the top plate 34 and the base plate 38. The leaves have a vertically centered aperture 62 located at the inflection point of their s-shape as illustrated in FIG. 8. A shaft 33 emerges longitudinally from a central location of the heel connection 35 and pivotably secures the leaves 48, 50 by extending through the aperture 62. The shaft 33 extends through a slotted guide 44 which restricts lateral movement of the spring assembly 46. Concentric to the aperture 62, the leaves have opposing, central area, notches extending a distance equaling one half their longitudinal depth. The notches extend toward the curved ends and taper to points. The points being separated by generally perpendicular planar surfaces 63 which project out, in a longitudinal direction, causing the leaves to interlock. Angled strips of resilient material 47, such as spring steel, have a fixed end secured to a generally horizontal planar surface of a leaf and a free end slidably engaged with a generally vertical surface of an adjacent leaf. The curved ends fixedly secure screw studs 64 in a central location on their longitudinal surfaces. The studs 64 pivotably secure a group of ringed elastics 32. The elastics 32 are apositioned in horizontal pairs on the upper curved ends and the lower curved ends. These elastics 32 are similarly constructed as the ringed elastics 32 of the hinged leaf spring 30, only sized to fit the minimum horizontal distance separating each pair of studs 64.
A second embodiment 67 of the invention is disclosed in which the top plate 34 inclines downward toward the toe area of the platform 22 as shown in FIG. 11 such that the sole construction 18 fits within the outer covering of a shoe. A lobe 66 of lightweight, rigid, material, having a lower planar surface, is fixedly secured to the upper surface of the top plate 34. The lobe 66 is shaped to resemble, in combination, a portion of an upper foot and a lower ankle. The lobe 66 has a tapered upper end which contains a lateral aperture 68. The aperture 68 provides access for an axle to pivotably connect the foot prothesis 67 to the lower end of a user's artificial leg.
The sole construction 18 is comprised of three main elements; a heel mechanism or a hinged leaf spring 20, a frame or z-shaped platform 22, and a front mechanism or an x-shaped leaf spring 46. In use, these three elements relate directly to the three basic movements of a user's foot in forward motion which are; heel impact, roll-over, and metatarsal thrust. Roll-over is a pendulum-like movement which occurs as a person's weight seesaws from the heel area to the metatarsal area of the foot. As the user enters a stride, the heel's impact with the ground causes a downward force which urges the lower ends of the hinged leaf spring 30 to slide in opposite directions on the upper surface of the base plate 38 and tension the resilient, elastic material in the ringed elastics 32 as shown in FIGS. 4 and 5. As the lower ends of spring 30 separate, the upper ends rotate in opposite directions around hinge pin 27 and rotate the free end of angled strip 26 toward it's fixed end, thereby absorbing energy. The hinge pin 27 restricts the leaves to longitudinal, vertical movement only, and eliminates the possibility of unwanted sidesway or lateral instability in the heel area.
The z-shaped frame 22 serves to precisely position the heel mechanism 30 under the heel of the user, and the front mechanism 46 under the metatarsals as shown in FIG. 1. The platform 22 also provides the central vertical support for roll-over to occur over, by acting as a double cantilever beam. The first cantilever is the diagonal plate 36, which has a fixed end at the toe connection 37 and a free end at the upper heel connection 35. The second cantilever is the top plate 34, which has a fixed end at the heel connection 35 and a free end at the toe end. Since resistance in a cantilever beam gradually increases toward the fixed end, an upwardly resisting force occurs at the midpoint of each cantilever as illustrated by arrows 29, 31 of FIG. 6. This upward resisting force provides the support which engages, and transmits to the ground, the user's natural roll-over movement.
The front mechanism, or x-spring 46 relates directly to the metatarsal thrust of a person's natural forward footplant movements. After heel impact, the user's weight rolls-over, or shifts forward and simultaneously releases the heel spring 30 as the weight is removed. During this release, the lower curved ends snap-back together and the angled strip 26 is also discharged, thereby providing thrust to the user as shown in FIG. 4, 5. Towards the latter part of the curved end's snap-back, and towards the latter phase of the roll-over, the front x-spring 46 is quickly depressed and released, adding thrust as shown in FIG. 9, 10. The downward force of weight and momentum sandwiches the outer curved ends of the x spring 46 between the inner surfaces of the top plate 34 and the base plate 38. The outer ends slide apart as the leaves 48, 50 rotate in opposite directions around the shaft 33. As the outer ends separate, the elastic inner link of the ringed elastics 32 is stretched apart and the angled strips are rotated closed. When the weight is released, the outer ends snap-back, the angled strips are released, and thrust is added to the user. Since the leaves 48,50, are s-shaped and pivotably secured at their inflection point, as the right lateral side descends, so does the left lateral side, thereby precluding independent sidesway or lateral instability. As the outer ends separate, the distance between their balance points increase, and lateral stability also increases.
Adjustability is affected by exchanging the ringed elastics in the front 46 and rear 30 mechanism. The hinged leaf spring 30 is rotated rearward, the lower shafts 53 are pulled and a different set of ringed elastics 32 are rethreaded on shafts 53. The front elastics 32 are simply pulled off the screw studs 64 and exchanged. The rigid, outer chain links of the ringed elastic assembly 32 are comprised of coils of spring steel, similiar to a key ring, where an end can be pryed apart and a certain quantity of elastic bands can be inserted within the coils, thereby permitting the user to simply and quickly adjust the spring rates by varying the quantity of elastics.
The theory of operation assumes that a person in forward motion, first lands on the heel, then rolls his or her weight over a midpoint, and concludes with a metatarsal thrust. It is further assumed that a device designed to amplify the stride must directly emulate these three basic movements in order to provide comfort to the user. It is still farther assumed that forward kenetic energy is lost, in the form shock, during heel impact. The theory predicts that a device can be built that provides comfort and stride amplification to the user if it is comprised of energy storage mechanisms and a supporting structure which closely relate to the above stated basic natural movements. Additional requirements for lateral stability, low relative weight, and adjustability are implied in the basic need for comfort.
The sole construction 18 is designed to meet the specifications required by the theory. The hinged leaf spring 30, acting in combination with the angled strip 26, closely relates to, a person's natural heel impact and also stores all the heel impact energy which may be as high as three times the user's weight. When the weight is rolled over, the stored energy is released in the form of thrust. The thrust is partially dependent on the rate of snap-back of the hinged spring 30, therefore it is advantageous to choose an elastic material with the highest rate of snap-back or resiliency. The thickness of the angled strip 26 determines it's energy absorption ability and is sized by the user's weight class. The user can adjust the spring rate of the hinged spring 30 by varying the quantity of elastics in the center link of the ringed elastics 32. In order to maximize thrust, the deflection should be gaged to closely approach it's maximum during use, based on the user's weight and anticipated rate of forward motion, such as a walk, jog, or run. The heel mechanism 30, having it's upper ends pin connected in a lateral direction to the frame 22, precludes unwanted lateral motion or sidesway, and restricts the movement to longitudinal axial motion only. It is also advantageous to use construction materials having the lowest weight to strength ratios along with the desired flexibility per component.
The z-shaped platform 22 as shown in FIG. 1 provides the supporting structure which houses and precisely aligns the energy storage mechanisms. Although the frame 22 is comprised of flexible and resilient material, it does not serve to store and release a significant quantity of energy. The frame's double cantilever arrangement allows significant deflection to occur in the heel and toe areas, but supports the user's weight in a central area, dining the roll-over phase. The diagonal plate 36 acts as the first cantilever beam with a fixed end at the toe connection 37, and the top plate 34 acts as the second cantilever with a fixed end at the heel connection 35. These cantilever beams provide upward resistance across a lateral midsection, which serves, in effect, as a central, lateral, support for the user's weight to seesaw across. The z-shaped frame 22 closely relates to, and transmits to the ground, a person's natural roll-over movement.
As the rear assembly 30, 26 is providing thrust, and towards the latter part of the roll-over phase, the x-spring assembly 46 engages the user's metatarsal thrust. This occurs toward the end of footplant and is a quick action, which, upon release, adds thrust. Lateral stability is inherently derived due to the s-shape of the leaves 48, 50 and their pin connection at their inflection point as shown in FIG. 9, 10. When the spring 46 is depressed, an upper curved end of a leaf separates from it's neighbor, the diagonal lower curved end, being the lower half of the same s-shaped leaf, must also separate from its neighbor due to the pinned connection at 62, which, thereby, precludes independent lateral movement. Indeed, as the curved ends separate, stability increases because the distance between the balance points also increases. Adjustability is affected by varying the quantity of elastics in the tinged elastics 32 and by varying the thickness of the angled strips 47. The angled strips 47, 26 also serve as stops against excessive deflection as shown in FIGS. 5, 10. Since their radii are essentially incompressible, the angled strips provide a hardening spring rate toward the state of maximum deflection.
A still further assumption is that a person, in forward motion, will tend to maintain a constant velocity. This would infer that a device such as the sole construction 18 would undergo a regular, cyclic, pattern of spring compressions and expansions. This regular cycle of spring actions constitute a forcing frequency. The sole construction 18 tends to have a predominant natural frequency which lies within the range of possible forcing frequencies. When the forcing frequency equals the natural frequency resonance occurs which results in an amplification factor or a zone of enhanced effect. It is advantageous for the user to attain this zone by adjusting the various spring rates.
Accordingly, the reader will see that the sole construction 18 of this invention can provide stride amplification to the user in a comfortable and safe manner;
by emulating a person's natural foot movements,
by providing adjustable spring mechanisms,
by being inherently laterally stable,
and by having low relative weight.
Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. For example, the longitudinal shaft 33 can emerge from the guide 44 rather than the heel connection 35.
Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given. | A lightweight sole construction to be secured beneath a shoe for comfortable stride amplification by absorbing and releasing a user's impact energy. The invention accomplishes this by providing three primary elements which emulate, in sequence, the three basic movements of a forwardly moving foot in contact with the ground which are; heel impact, roll-over, and metatarsal thrust. A hinged leaf spring, having a pair of hinged leaves sandwiched in the heel area of a frame, absorbs energy by tensioning a group of ringed elastics as it's lower curved ends separate. An x-shaped leaf spring, being sandwiched in the toe area between a top and base plate, engages and emulates the user's metatarsal thrust by having free ends which slide apart when depressed and stretch a group of ringed elastics while pivoting about a central axis. A z-shaped platform houses and aligns the spring devices while providing a central support for the user's weight to roll-over. The device affords comfort to the user by employing spring mechanisms that inherently resist unwanted movements such as sidesway, and which are easily adjustable. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to European application 13175484.8 filed Jul. 8, 2013, the contents of which are hereby incorporated in its entirety.
TECHNICAL FIELD
[0002] The invention refers to a combined cycle power plant with integrated fuel gas preheating. The invention additionally refers to a method for operating a combined cycle power plant with integrated fuel gas preheating.
BACKGROUND OF THE DISCLOSURE
[0003] A CCPP (combined cycle power plant) is a power plant in combination of a gas turbine and a steam turbine with a high thermal efficiency so constructed as to lead high temperature exhaust gas from the gas turbine to a heat recovery steam generator (HRSG) and to generate steam by heat energy retained in the exhaust gas. This steam enables the power generation by the steam turbine, and coupled with power generated by the gas turbine, it is possible to improve thermal efficiency equivalent to thermal energy retained in exhaust gas compared with the independent power generation by a gas turbine.
[0004] For improving thermal efficiency of a CCPP, it is most effective to increase the hot gas temperature at the inlet of gas turbine to a higher temperature. However, even with the latest material and combustion technology, the hot gas temperatures are limited due to life time and emission reasons. To further increase the efficiency of CCPPs fuel gas preheating has been proposed.
[0005] The EP0931911 A2 describes the extraction of high pressure feed water upstream of a high pressure drum to preheat the fuel gas. The cold HP water is then sub-cooled and discharged to the main condenser.
[0006] The use of such fuel gas preheating systems improves the overall efficiency. However, it incurs mayor energy losses because high grade heat from a high pressure level is used.
[0007] The DE 10 2007 054 467 A1 describes a stepwise preheating using different heat sources from the intermediate pressure and low pressure level of the water steam cycle. After extracting heat the water used for preheating is returned to the is low pressure system of the HRSG. The system described in DE 10 2007 054 467 A1 can lead to improved efficiency but is complex and expensive. In addition all return streams lead to the low pressure system thereby incurring corresponding losses.
SUMMARY OF THE DISCLOSURE
[0008] The object of the present disclosure is to propose a CCPP (combined cycle power plant) with a fuel gas preheating which effectively uses heat from the water steam cycle to achieve high plant efficiency and a minimum power loss due to fuel gas preheating.
[0009] According to one embodiment such a CCPP comprises a gas turbine, and a water steam cycle with a steam turbine, and a HRSG (heat recovery steam generator) with at least two pressure levels. It further comprises a fuel gas preheating for preheating the fuel of the gas turbine with a first heat exchanger for preheating the fuel gas to a first elevated temperature and a second heat exchanger for further preheating the fuel gas to a second elevated temperature. The first heat exchanger uses heat extracted from a lower pressure level of the water steam cycle, and a second heat exchanger uses heat extracted from the highest pressure level of the water steam cycle. To this end the first heat exchanger for preheating the fuel gas to the first elevated temperature is connected to a feed water line from a pressure level of the HRSG, which is below the highest HRSG pressure level, for feeding feed water into the first heat exchanger. The second heat exchanger for further preheating the fuel gas to the second elevated temperature is connected to the high pressure feed water with the highest pressure level of the HRSG for feeding high pressure feed water to the second heat exchanger.
[0010] The proposed fuel preheating leads to noticeable advantages over the prior art. First of all, the use of two heat sources with different temperatures leads to an increased efficiency. Further, the re-introduction of the return water into the feed water system reduces the total pressure losses incurred on the water side due to the fuel preheating.
[0011] Due to the use of two stage pre-heaters the size of the heat exchanger operating at the high pressure level can be reduced. The first heat exchanger has a lower design pressure thereby reducing the cost.
[0012] Because water leaving the fuel gas preheater is reintroduced to the feed water system the size of the feed water pump for the respective pressure level into which the water is returned can be reduced.
[0013] By using a two stage fuel pre-heater the fuel can economically be preheated to higher temperatures. The fuel gas can be preheated to a temperature in the range of for example 270 to 350° C. In particular it can be preheated to a temperature in the range of for example 290 to 310° C.
[0014] The use of water for preheating is thermodynamically more efficient than the use of steam. Further it allows the use of smaller heat exchangers.
[0015] In an embodiment of the CCPP the first heat exchanger is connected to a low pressure feed water line or to a medium pressure feed water line of the HRSG for preheating the fuel gas to the first elevated temperature. The second heat exchanger for fuel preheating is connected to the exit of the economizer of the HRSG using high pressure feed water to preheat the fuel gas to the second elevated temperature. The first heat exchanger can for example be connected to the low pressure feed water line or to the medium pressure feed water line downstream of the economizer. It can also for example be connected to the feed water lines in the middle of the economizer.
[0016] In this context the expression feed water line can be used for the lines for feeding water into the drums of the HRSG. For each pressure level a HRSG typically comprises a feed water supply with an economizer for preheating the feed water, a drum, an evaporator, and a superheater.
[0017] According to a further embodiment of the CCPP a booster pump is connected to a water outlet of the second heat exchanger to re-pressurize the feed water leaving the second heat exchanger to the inlet pressure of the high pressure economizer.
[0018] Alternatively or in combination the water outlet of the second heat exchanger can be connected to feed water line of a lower pressure level of the HRSG or to a drum of a lower pressure level of the HRSG. For a HRSG with three pressure levels, i.e. a low, medium, and high pressure level the water outlet of the second heat exchanger can for example be connected to the medium pressure feed water line or to the low pressure feed water line.
[0019] According to yet a further embodiment of the CCPP a booster pump is connected to the water outlet of the first heat exchanger to re-pressurize the feed water leaving the first heat exchanger to the pressure level of the feed water used for the first heat exchanger.
[0020] Alternatively or in combination the water outlet of first heat exchanger is connected to the next lower feed water line or to a drum of the next lower pressure level.
[0021] For a HRSG with three pressure levels the first heat exchanger can be connected to the medium pressure feed water line, for example downstream of the economizer. The outlet of the first heat exchanger can be connected to a booster pump that re-pressurize the feed water leaving the first heat exchanger to the pressure level of the medium pressure feed water for feeding the return water back into the medium pressure economizer.
[0022] The water outlet of the first heat exchanger can also be connected to the feed water line or to a drum of the next lower pressure level, i.e. the low pressure feed water line or drum.
[0023] According to one embodiment the water steam cycle comprises a low pressure level, a medium pressure level and a high pressure level. In this plant the first heat exchanger for preheating fuel gas is connected to the exit of a low pressure economizer or the exit of a medium pressure economizer and the second heat exchanger for preheating fuel gas is connected to the exit of a high pressure economizer.
[0024] The typical pressure range for the high pressure level is 130 to 250 bar, preferably 150 to 220 bar at base load operation. For the medium pressure level the typical pressure range is 30 bar to 100 bar, preferably 50 to 80 bar at base load operation.
[0025] According to a further embodiment of a CCPP with a HRSG having three pressure levels the first heat exchanger for preheating the fuel gas to the first elevated temperature is connected to the low pressure economizer or to the medium pressure economizer ( 31 ), and the second heat exchanger for further preheating the fuel gas to the second elevated temperature is connected to the high pressure economizer.
[0026] Alternatively or in combination the exit of the second heat exchanger can be connected to the inlet of an intermediate pressure drum or to the inlet of a low pressure drum.
[0027] According to a further embodiment of a combined cycle power with a HRSG having three pressure levels the exit of the second heat exchanger can be connected to the inlet of the high pressure economizer or to middle of the high pressure economizer. Typically a booster pump can be used to re-pressurize the water leaving the second heat exchanger to feed it back into the high pressure economizer.
[0028] According to a further embodiment of a combined cycle it comprises a flash tank connected to the water outlet of the second heat exchanger. In the flash tank the pressure is lowered by flashing the inlet water into the tank and thereby releasing steam. The flashed steam can be used in steam turbine to produce power and the remaining water returned to a feed water system of the HRSG at a suitable pressure vessel. For this the water outlet of the flash tank can be connected to the feed water system of the water steam cycle, and the steam outlet of the flash tank can be connected to the steam turbine via a steam line. The use of a flash tank can be considered if the water leaving the second heat exchanger is not re-pressurized but returned to a feed water system at a lower pressure level. If the pressure of the water leaving second heat exchanger is much higher than the pressure level of the feed water system's pressure to which it is added and its temperature still above the boiling temperature at the feed water system pressure use of flash tank can be advantageous. The remaining heat in the return water can be used for power production and the water is available at the required pressure.
[0029] The flash tank can for example be connected to a medium pressure or low pressure inter-stage steam feed of the steam turbine.
[0030] The fuel preheating can be arranged and used for preheating the fuel gas of the gas turbine of the CCPP. Optionally the HRSG can comprise a supplementary firing. An optional separate fuel gas preheating can be arranged for preheating the fuel of the supplementary firing or one fuel gas preheating can be provided which has sufficient capacity to preheat the fuel for the gas turbine and the supplementary firing. Fuel gas preheating for the supplementary firing can increase the net efficiency of the plant operating with supplementary firing but leads to additional cost and complexity of the plant. Its application needs to be carefully evaluated based on the expected operating time and regime with supplementary firing.
[0031] Typically the feed water is branched off to the fuel preheater from the HRSG feed water system after it is heated in an economizer in a line from the economizer to the drum of respective pressure level. Depending on the heat requirements and the temperature level of the feed water the line from feed water system to heat exchanger for fuel gas preheating can be branched off in the middle of the economizer or even upstream of the economizer.
[0032] Besides the CCPP a method for operating such a CCPP is subject of the present disclosure. Such a method can be used for operating a CCPP comprising a gas turbine, a steam turbine, a water steam cycle with HRSG with at least two pressure levels, and a fuel gas preheating for preheating the fuel of the gas turbine. According to the proposed method the fuel is preheated to a first elevated temperature using feed water from a pressure level of the HRSG, which is below the highest HRSG pressure level, in a first heat exchanger. After passing through the first heat exchanger the fuel is further preheated to a second elevated temperature in a second heat exchanger using high pressure feed water with the highest pressure level of the HRSG. The high pressure feed water is branched off from the HRSG feed water system and fed to the second heat exchanger.
[0033] According to one embodiment of the method the HRSG is operated with three pressure levels. Low pressure feed water or medium pressure feed water is fed to the first heat exchanger for preheating the fuel gas to the first elevated temperature, and in that high pressure feed water is heated in a high pressure economizer, and at least part of the heated high pressure feed water is fed into the second heat exchanger for preheating the fuel gas to the second elevated temperature.
[0034] According to a further embodiment of the method the water leaving the second heat exchanger is returned into the feed water system of a lower pressure level. During low load operation of the gas turbine a medium pressure feed water control valve, which controls the feed water flow from the economizer to the drum in the respective pressure level of the HRSG, is closed. The water flowing through the economizer can be fed to the first heat exchanger. At the same time a second heat exchanger control valve, which controls the water flow through the second heat exchanger, is used to control the water level of the drum into which the high pressure return water is returned. In this operating mode the fuel gas temperature after the second heat exchanger cannot be controlled to the design level but is a result of the available heat provided with the resulting water flow. The resulting temperature control is also called sliding temperature control.
[0035] At high part load operation and base load operation of the gas turbine the medium pressure feed water control valve is at least partly open and used to control the water level of the drum. A second heat exchanger control valve can be used to control the temperature to which the fuel gas is preheated by controlling the feed water flow through the second heat exchanger.
[0036] According to another embodiment of the method the water discharged from the second heat exchanger is re-pressurize by a booster pump to the inlet pressure of the high pressure economizer. Alternatively the water discharged from the second heat exchanger is fed to a feed water line or to a drum of a lower pressure level of the HRSG.
[0037] The method can be used for preheating the fuel of the gas turbine. In addition or combination it can be used for preheating fuel gas of a supplementary firing of the HRSG.
[0038] Typically two stage fuel preheating is used for fuel gas; however it can also be used for liquid fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The disclosure, its nature as well as its advantages, shall be described in more detail below with the aid of the accompanying schematic drawings. Referring to the drawings:
[0040] FIG. 1 schematically shows a CCPP with a gas turbine, a HRSG with supplementary firing, and fuel gas preheating.
[0041] FIG. 2 schematically shows a HRSG with three pressure levels and fuel gas preheater.
[0042] FIG. 3 schematically shows a HRSG with two pressure levels and fuel gas preheater.
[0043] FIG. 4 schematically shows a HRSG with three pressure levels, fuel gas preheater and a booster pump to re-pressurize the return water from second heat exchanger of the fuel gas preheater to the high pressure feed water of the HRSG.
[0044] FIG. 5 schematically shows a HRSG with three pressure levels, fuel gas preheater and release of the first and second heat exchanger outlet water to the respective next lower feed water pressure level of the HRSG.
[0045] FIG. 6 schematically shows a HRSG with three pressure levels, fuel gas preheater and a flash tank to generate steam from the return water of the second heat exchanger.
[0046] FIG. 7 schematically shows a HRSG with three pressure levels, a once through steam generator at high pressure and fuel gas preheater.
DETAILED DESCRIPTION
[0047] A power plant for execution of the proposed method comprises a conventional CCPP, and a fuel preheater 2 . Optionally the HRSG can be equipment a supplementary firing 10 ,
[0048] A typical arrangement with fuel gas preheating is shown in FIG. 1 . A gas turbine 6 , which drives a first generator 25 , is supplied with compressor inlet gas 3 , and fuel 17 . The compressor inlet gas 3 is compressed in the compressor 1 and the fuel 17 is heated to supply preheated fuel 18 in the fuel preheater 2 . The compressed gas is used for combustion of preheated fuel 18 in a combustor 4 , and pressurized hot gasses expand in a turbine 7 . The gas turbine's 6 main outputs are electric power, and hot flue gasses 8 .
[0049] The gas turbine's hot flue gasses 8 pass through a HRSG 9 , which generates steam for a steam turbine 13 . In the HRSG 9 or the flue gas duct from the gas turbine 6 to the HRSG 9 a supplementary firing 10 can optionally be integrated. The supplementary firing 10 is supplied with fuel 11 . Optionally preheated fuel 18 can be supplied to the supplementary firing 10 .
[0050] The steam turbine 13 is either arranged as a single shaft configuration with the gas turbine 6 and the first generator 25 (not shown), or is arranged as a multi shaft configuration to drive a second generator 26 . The steam leaving the steam turbine 13 is condensed in the condensator 14 . The condensate is collected in the feed water tank 15 , re-pressurised by a feed water pump 12 and returned to the HRSG 9 . In FIG. 1 only one feed water pump 12 , one line for feed water 16 , and one steam turbine 13 are shown.
[0051] The steam cycle is simplified and shown schematically without different steam pressure levels, feed water pumps, etc. Depending on the HRSG 9 design the feed water is pressurized to two, three or more pressure levels. Accordingly the number of feed water pumps feed water supply lines, and steam turbine will increase to two, three or a higher number. Examples with two and three pressure levels are shown in more detail in the subsequent Figures.
[0052] Different exemplary embodiments of the HRSG 9 with fuel preheater 2 are shown in FIGS. 2 to 6 . For simplification no subsequent firing is shown in these Figures and the steam turbines with different pressure levels and additional feed lines are omitted.
[0053] The embodiment of FIG. 2 shows a HRSG with three pressure levels (low, medium and high pressure) and a fuel preheater 2 . The hot flue gases from the gas turbine 8 flow through the HRSG 9 . In the schematic the hot flue gases pass through a high pressure evaporator 22 , a high pressure economizer 30 , a medium pressure evaporator 23 , a medium pressure economizer 31 , and a low pressure evaporator 24 , a low pressure economizer 32 . Typically a superheater is arranged upstream of each evaporator 22 , 23 , 24 in the hot flue gas 8 flow path. After the useful heat is extracted from the flue gas it leaves the HRGS 9 as flue gas to the stack 19 .
[0054] High pressure feed water is supplied to the high pressure economizer 30 via a high pressure feed water line 43 , medium pressure feed water is supplied to the medium pressure economizer 31 via a medium pressure feed water line 44 , and low pressure feed water is supplied to the low pressure economizer 32 via a low pressure feed water line 45 . The flow of low pressure feed water to the low pressure drum 29 is controlled by a low pressure feed water control valve 35 . The flow of medium pressure feed water to the medium pressure drum 28 is controlled by a medium pressure feed water control valve 34 , and the flow of high pressure feed water to the high pressure drum 27 is controlled by a high pressure feed water control valve 33 .
[0055] Water from the low pressure drum 29 is evaporated in the low pressure evaporator 24 and returned as steam to the low pressure drum 29 . Water from the medium pressure drum 28 is evaporated in the medium pressure evaporator 23 and returned as steam to the medium pressure drum 28 , and water from the high pressure drum 27 is evaporated in the high pressure evaporator 22 and returned as steam to the high pressure drum 27 . The steam of each respective drum 27 , 28 , 29 is fed to respective super heaters (not shown) and further to the steam turbine 13 , respectively to corresponding low, medium and high pressure steam turbines.
[0056] For fuel preheating medium pressure feed water 38 is branched off from the medium pressure feed water line after it is heated in the medium pressure economizer 31 and feed into the first heat exchanger 20 of the fuel preheater 2 to preheat the cold fuel 17 to a first temperature level. The medium pressure return water 39 leaving the first heat exchanger 20 is discharged to the feed water tank 15 . The pressure in first heat exchanger 20 can for example be maintained by an orifice or control valve at the discharge into the feed water tank 15 .
[0057] High pressure feed water 36 is branched of the high pressure feed water line after it is heated in the high pressure economizer 30 . The branched off high pressure feed water 36 is fed into the second heat exchanger 21 of the fuel preheater 2 to further preheat the fuel to a second temperature level. The high pressure return water 37 leaving the second heat exchanger 21 is fed to the medium pressure drum 28 thus further utilizing its high pressure level and remaining heat in the water steam cycle. The heat release in the second heat exchanger 21 can be controlled by controlling the water flow through the second heat exchanger 21 . In the example shown the water flow is controlled by the second heat exchanger control valve 40 .
[0058] The schematic FIG. 3 is a simplification of a HRSG 9 with fuel preheater 2 based on FIG. 2 . In this example the HRSG 9 has only two pressure levels. For cost reasons and simplification of the plant one pressure level is omitted. Based on FIG. 2 the low pressure level is omitted. The medium pressure level could also be called low pressure level; however the naming remains unchanged in this example. Based on FIG. 2 simply the low pressure economizer 32 with low pressure feed water line 45 , low pressure feed water control valve 35 as well as low pressure drum 29 and low pressure evaporator 24 are omitted. The flue gas to the stack 19 is released from the HRSG 9 downstream of the medium pressure economizer 31 .
[0059] FIG. 4 schematically shows another example of a HRSG 9 with three pressure levels. This example is a modification based on the arrangement of FIG. 2 . Instead of feeding the high pressure return water 37 leaving the second heat exchanger 21 to the medium pressure drum 28 it is re-pressurized in by booster pump 48 and returned to the high pressure feed water line 43 upstream of the high pressure economizer 30 . Thereby the high pressure feed water flow coming from the high pressure feed water pump can be reduced and the high pressure level and remaining heat of the return water from the second heat exchanger 21 can be efficiently used. Also in this example the heat release in the second heat exchanger 21 can be controlled by controlling the water flow through the second heat exchanger 21 . In the example shown the water flow is controlled by controlling the booster pump 48 , e.g. with a variable speed drive.
[0060] FIG. 5 schematically shows another example with a modification based on FIG. 2 . In this example the medium pressure return water 39 leaving the first heat exchanger 20 is not discharged to the feed water tank 15 . Here the medium pressure return water 39 is fed to the low pressure drum 29 thus using its pressure level and remaining heat. The heat release in the first heat exchanger 20 can be controlled by controlling the water flow through the first heat exchanger 20 . In the example shown the water flow is controlled by the first heat exchanger control valve 41 .
[0061] FIG. 6 schematically shows yet another example of a HRSG 9 with three pressure levels, and a fuel preheater 2 . It shows a modification based on the example of FIG. 2 . Instead of feeding the high pressure return water 37 leaving the second heat exchanger 21 to the medium pressure drum 28 it is discharged into a flash tank 42 to generate steam from the return water 37 of the second heat exchanger 21 . The steam can be fed via a flash steam line 46 to the steam turbine 13 . The remaining water can be fed back into the medium pressure feed water line 44 . To control the second heat exchanger 21 a second heat exchanger control valve 40 is arranged upstream of the flash tank 42 .
[0062] FIG. 7 schematically shows another example of a HRSG 9 with three pressure levels, and a fuel preheater 2 . It shows a modification based on the example of FIG. 2 . The steam generator of the high pressure level does not comprise an evaporator, boiler and super heater. Instead, it comprises a once through steam generator 49 at high pressure level.
[0063] A once through steam generator can also be used for the medium and low pressure level and in any combination of pressure levels.
[0064] All the explained advantages are not limited to the specified combinations but can also be used in other combinations or alone without departing from the scope of the disclosure. Other possibilities are optionally conceivable, for example, for the return water from the first heat exchanger can also be supplied to a flash tank for producing low pressure steam for a low pressure steam turbine. | The invention refers to a CCPP comprising a gas turbine, a water steam cycle with a steam turbine and a HRSG with at least two pressure levels, and a fuel preheater for preheating the fuel of the gas turbine. The fuel preheater includes a first heat exchanger for preheating the fuel to a first elevated temperature, which is connected to a feed water line from a pressure level of the HRSG, which is below the highest HRSG pressure level, and a second heat exchanger for further preheating the fuel gas to a second elevated temperature, which is connected to the high pressure feed water with the highest pressure level of the HRSG. The disclosure further refers to a method for operating a CCPP with such a fuel preheater. | 8 |
FIELD
In exemplary embodiment is directed toward enhancing communications understandability. More specifically, an exemplary embodiment is directed toward an automatic real-time correction of a type of mispronunciation that is common when people speak a language other then the one to which they are accustomed.
BACKGROUND
Even when two people are speaking the same language, and have a good command of that language's vocabulary and grammar, differences between them in their manner of speaking, e.g., accent, pronunciation accuracy, prosody, speech, pitch, cadence, intonation, co-articulation, syllable emphasis, and syllable duration, can affect the ease with which they understand each other's speech.
In theory, it should be possible to process the speech from person A and manipulate it digitally so that the aspects of A's speech that make it hard for B to understand are reduced or eliminated. In practice, it is hard to envision being able to do this reliably for all of the above factors in anything close to real-time. This is because appropriate automatic manipulation of most of the above factors cannot be achieved by a straight-forward acoustic analysis, and would instead require a syntactic and semantic understanding of what is being said. One exception of this is syllable duration.
Nearly all modern speech-based computer and communication systems transmit, route, or store speech digitally. One obvious advantage of digital techniques over analog is the ability to provide superior audio quality (for example, compact discs versus phonograph records, or digital cellular telephones versus analog). Other advantages include the ability to send many more simultaneous transmissions over a single communications channel, route speech communication through computer-based switching systems, and store the speech on computer disks and in solid-state memory devices.
The following describes techniques that reduce the amount of data required to digitize speech.
Speech Digitization
The simplest way to encode speech digitally is to generate a sequence of numbers that, in essence, trace the ‘ups and downs’ of the original speech waveform. For example, if one wished to digitize a waveform in which all of the important acoustic information is below 4000 Hertz (4000 cycles per second), the basic steps of this analog-to-digital conversion would include the following:
(1) Filter from the original signal all information above 4000 Hertz.
(2) Divide the original signal into 8000 segments per second.
(3) Go through the segments in order, measuring and recording the average amplitude of the waveform within each segment.
The purpose of the first step is to prevent ‘aliasing’—the creation of false artifacts, caused by the undesired interaction of the sampling rate with the frequency of the observed events. The phenomenon in motion pictures, where the spokes of a rapidly rotating wheel may appear to be standing still or even moving backwards, is an example of aliasing.
The second step, sampling at twice the frequency of the highest-frequency sine wave, is necessary in order to capture both the peaks and the valleys of the wave.
To envision the third step more easily, imagine that the original waveform is drawn on a sheet of paper. Within every segment, each of which represents 1/8000 of a second, the height of the waveform is measured with a ruler. The sequence of numbers obtained in this manner constitutes a digital representation of the original waveform.
Regarding the ‘ruler’ used to measure within-segment speech amplitudes, speech quality comparable to that of a modern telephone requires twelve bits per segment, 8000 segments per second. (As a point of comparison, audio compact discs use 16 bits per segment, with 44,100 segments per second.) The resulting data rate of 96,000 bits per second means that a typical 1.44 MB floppy diskette can hold only about two minutes of telephone-quality speech.
Modest reductions in the data rate can be achieved by using logarithmic amplitude encoding schemes. These techniques, which represent small amplitudes with greater accuracy than large amplitudes, achieve voice quality equivalent to a standard twelve-bit system with as few as eight bits per segment. Examples include the μ-law (pronounced ‘myoo law’) coding found on many U.S. digital telephones, and the A-law coding commonly used in Europe.
For many applications in which the cost of transmission or the cost of storage is important, such as wireless telephony or voice mail systems, the data rate reductions achieved with simple μ-law and A-law encoding are inadequate. One way to achieve significant reductions in the data rate is to extract and digitize the frequency content of the waveform (rather than simply digitize the shape of the waveform).
Many coders that work in this manner have software components that map to physical components of the human vocal mechanism. They reduce the data rate by encoding only the parameters that control the changeable components of the speech production model—for example, the parameter that controls overall amplitude and the parameter that adjusts the fundamental pitch of the electronic ‘vocal cords.’
The Human Speech Production Mechanism
Given that many components in these coders have physiological counterparts, it is helpful to understand the human vocal mechanism prior to examining the coders.
The major physical components of the human speech mechanism include the lungs, the vocal cords, and the vocal cavity. When a person speaks, the lungs force air past the vocal cords and through the vocal cavity. The pressure with which the air is exhaled determines the final amplitude, or ‘loudness,’ of the speech. The action of the vocal cords on the breath stream determines whether the speech sound will be voiced or unvoiced.
Voiced speech sounds (for example, the ‘v’ sound in ‘voice’) are produced by tensing the vocal cords while exhaling. The tensed vocal cords briefly interrupt the flow of air, releasing it in short periodic bursts. The greater the frequency with which the bursts are released, the higher the pitch.
Unvoiced sounds (for example, the final ‘s’ sound in ‘voice’) are produced when air is forced past relaxed vocal cords. The relaxed cords do not interrupt the air flow; the sound is instead generated by audible turbulence in the vocal tract. A simple demonstration of the role of the vocal cords in producing voiced and unvoiced sounds can be had by placing one's fingers lightly on the larynx, or voice box, while slowly saying the word ‘voice’; the vocal cords will be felt to vibrate for the ‘v’ sound and for the double vowel (or diphthong) ‘oi’ but not for the final ‘s’ sound.
The mechanisms described above produce what is called the excitation signal for speech. Many properties of the excitation signal will differ when comparing one person to another. However, when examining a single individual, only three parameters in the excitation signal will vary as the person speaks: the amplitude of the sound, the proportion of the sound that is voiced or unvoiced, and the fundamental pitch. This can be demonstrated easily. If one were to hold one's mouth wide open, without any movement of the jaw, tongue, or lips, the only remaining changeable characteristics of sound generated by the vocal system are the above three parameters.
At any given time, excitation signals actually contain sounds at many different frequencies. A voiced excitation signal is periodic. The energy in its frequency spectrum lies at multiples of the fundamental pitch, which is equal to the frequency with which the vocal cords are vibrating. An unvoiced excitation signal contains a random mixture of frequencies similar to what is generally called white noise.
The vocal cavity ‘shapes’ the excitation signal into recognizable speech sounds by attenuating certain frequencies in the signal while amplifying others. The vocal cavity is able to accomplish this spectral shaping because it resonates at frequencies that vary depending on the positions of the jaw, tongue, and lips. Frequencies in the excitation signal are suppressed if they are not near a vocal cavity resonance. However, vocal cavity resonances tend to amplify, or make louder, sounds of the same frequency in the excitation signal. The resulting spectral peaks in the speech sounds are called formants. Typically, only the three or four lowest-frequency formants will be below 5000 Hertz. These are the formants most important for intelligibility.
(The upper frequency limit for many audio communication systems, including the public telephone system in the United States, is on the order of 3400 Hertz. This is why speech sounds that differ chiefly in their upper-frequency formant structure, such as ‘f’ and ‘s’, tend to be hard to distinguish on these systems.)
For spoken English, a simple classification of speech sounds according to manner of formation would include vowel, nasal, fricative, and plosive sounds. In the formation of vowels, such as the ‘ee’ sound in ‘speech’ and the diphthong ‘oi’ in ‘voice,’ the breath stream passes relatively unhindered through the pharynx and the open mouth. In nasal sounds, such as the ‘m’ and ‘n’ in ‘man,’ the breath stream passes through the nose. Fricative sounds are produced by forcing air from the lungs through a constriction in the vocal tract so that audible turbulence results. Examples of fricatives include the ‘s’ and ‘ch’ sounds in ‘speech.’ Plosive sounds are created by the sudden release of built-up air pressure in the vocal tract, following the complete closure of the tract with the lips or tongue. The word ‘talk’ contains the plosive sounds T and ‘k’. Except when whispering, the vowel and nasal sounds of spoken English are voiced. Fricative and plosive sounds may be voiced (as in ‘vast’ or ‘den’) or unvoiced (as in ‘fast’ or ‘ten’).
Speech Compression
The parameters computed by coders that follow this vocal tract model fall into two categories: those that control the generation of the excitation signal, and those that control the filtering of the excitation signal.
Two different signal-generating mechanisms are required in order to produce a human-like excitation signal. One mechanism generates a periodic signal that simulates the sound produced by vibrating human vocal cords. The other produces a random signal, similar to white noise, that is suitable for modeling unvoiced sounds. Thus, when a voiced sound must be produced, such as the ‘ee’ in ‘speech,’ the output from the periodic signal generator is used; for the unvoiced ‘sp’ and ‘ch’ sounds in ‘speech,’ the random output from the other generator is used.
In some systems, a weighted combination of the random and periodic excitation is used. This can be helpful in modeling voiced fricative sounds, such as the ‘z’ sound in the word ‘zoo.’ However, many coders restrict the excitation so that it is modeled entirely by either the voiced or unvoiced excitation source. In these coders, selection of the excitation is controlled by a two-valued voicing parameter, typically referred to as the voiced/unvoiced decision.
In addition to the voiced/unvoiced decision, the excitation function is scaled by an amplitude parameter, which adjusts its loudness. Finally, if the system is to generate something other than a monotone, it is necessary for the period of the voiced excitation source to be variable. The parameter that controls this is called the pitch parameter. In summary, three parameters are sufficient to control a simple excitation model (i.e., a model that does not take into account vocal tract differences among people): an amplitude parameter; a voiced/unvoiced parameter; and, if voiced, a pitch parameter that specifies the fundamental periodicity of the speech signal.
Various techniques have been used to simulate the manner in which the human vocal cavity imposes a particular spectral shape on the excitation signal. One of the first techniques developed uses a bank of bandpass filters, similar in many respects to the adjustable multi-band ‘graphic equalizers’ found on some high-end stereo systems. The center frequencies of these filters are fixed; an adjustment in the gain of each filter or channel allows the desired spectrum to be approximated, in much the same way that the spectral characteristics of a stereo system may be varied by adjusting the tone controls.
The chief drawback to this approach is the large number of filters it requires. The number of filters can be reduced if it is possible to control their center frequencies. Specifically, by matching the center frequencies of filters to the desired formant frequencies, one can encode speech with only three or four tunable bandpass filters. The important point here is that, even though the center frequencies of the filters must now be encoded along with the gains of the filters, the total number of parameters required for accurate shaping of the excitation signal is reduced greatly.
Although early speech synthesis systems relied on analog mechanisms to filter and shape the excitation signal, modern speech compression systems rely entirely on digital filtering techniques. With these systems, the decoded speech signal heard at the receiving end is the output of a digitally controlled filter that has as its input the appropriate excitation sequence. Digital control of the filter is accomplished through the use of a mathematical model—in essence, an equation with constants and variables, in which the desired spectral filtering is specified by setting the appropriate values for the variables. Great reductions in the data transmission rate are achievable with this approach because the same mathematical model is pre-loaded into both the encoder and the decoder. Therefore, the only data that must be transmitted are the relatively small number of variables that control the model.
A good example is the technique known as linear prediction, in which speech samples are generated as a weighted linear combination of previous output samples and the present value of the filter input. This yields the following expression for each output sample (S[i]) as a function of previous samples (S[i−1], S[i−2], . . . , S[i−n]), the prediction weights (A[1], A[2], . . . , A[n]) and the filter input (U[i]):
S[i]=A[ 1 ]S[i− 1 ]+A[ 2 ]S[i− 2 ]+ . . . +A[n]S[i−n]+U[i]
The filter input in this equation (U[i]) is the product of the amplitude parameter and the excitation sequence. The total number of coefficients in the equation (n) determines how many spectral peaks, or formants, may be approximated.
Once the complete set of parameters (amplitude, voicing, pitch, and spectral parameters) has been specified, a speech decoder can produce a constant speech-like sound. In order to generate intelligible natural-sounding speech, the model parameters need to be updated as often as 40 to 50 times each second. To envision this process, it is helpful to recall how motion pictures work: apparent motion—in this case, a smoothly varying speech sound, rather than a smoothly varying image—is achieved by updating with sufficient frequency what are, in fact, still images. (Some systems that store speech in this format, such as Avaya's Intuity™ AUDIX® multimedia messaging system, allow users to adjust the playback rate without the shift in tone that would accompany, for example, playing a 33⅓ RPM phonograph record at 45. This is accomplished by adjusting how long each set of speech production parameters stays ‘in the gate’ before being updated, in much the same way that ‘slow motion’ is achieved with motion pictures.)
One of the first products to incorporate this style of speech compression was a children's learning aid introduced by Texas Instruments in 1978, the Speak & Spell®. It used ten-coefficient Linear Predictive Coding (LPC-10) to model speech. The data rate for this LPC-10 model was 2400 bits per second. (The actual data rate in the Speak & Spell is considerably less than 2400 bits per second because a one-bit repeat code was used when adjacent parameters were judged to be sufficiently similar.) This low data rate was achieved, in part, by ‘hard-wiring’ the excitation parameters that tend to vary from person to person. This meant that, if people's vocal tract characteristics differed from those that had been built into the speech production model, their voices could not be reproduced without distortion.
The ability to model a wide variety of voices accurately—as well as a variety of non-voice sounds, such as TTY/TDD tones—is achieved by systems in which the excitation function is not hard-wired, but is instead under software control. A good example is the Intuity AUDIX voice messaging system, which uses Code-Excited Linear Prediction (CELP) to model speech. The data rate for typical CELP-based systems ranges from 4800 bits per second to 16,000 bits per second. (The higher data rates are seen more frequently in systems where it is important to maximize the speech quality or reduce the computational complexity of the coder.) Compared with similar-quality uncompressed digitized speech, these techniques yield data rate reductions of at least six-to-one, and as high as twenty-to-one.
SUMMARY
A very common problem is that, when people speak a language other than the language which they are accustomed, syllables can be spoken for longer or shorter than the listener would regard as appropriate. An extreme example of this phenomenon can be observed when people who have a heavy Japanese accent speak English. Since Japanese words end with vowels instead of consonants (the only exception being words that end “n”), there is a tendency for native speakers of Japanese to add a vowel sound to the end of English words that should end with a consonant. Illustratively, native Japanese speakers often pronounce “orange” as “orenji.” An exemplary aspect of the technology described herein provides an automatic speech-correcting process that would not necessarily need to know that fruit is being discussed; the system would only need to know that the speaker is accustomed to Japanese, that the listener is accustomed to English, that “orenji” is not a word in English, and that “orenji” is a typical Japanese mispronunciation of the English word “orange.”
The ability to detect mispronunciations easily is just one of the factors that make appropriate syllable duration a correctable problem. The other is that frame-based speech encoding and compression techniques of the sort commonly used in telecommunication systems, such as linear predictive coding (LPC) and code excited linear prediction (CELP), include a parameter that specifies how long a specific speech sound should be reproduced. For this reason, a process that determines whether a sound (or syllable) has been spoken with the appropriate duration could, in real-time or close to real-time, correct the duration of errors it detects prior to presenting the speech to the listener by adding to or subtracting from the duration parameter that was computed during the initial coding of the speech. In addition, using the “orenji” example above, the “i” could be eliminated or reduced by the system by shortening or eliminating the time that the “i” spends in the gate. In addition, or optionally, the amplitude associated with the “i” could similarly be adjusted to reduce or eliminate it from the speech being presented to the listener.
Accordingly, an exemplary aspect is directed toward an automated telecommunication system adjunct that aids in speech understandability.
An additional aspect is directed toward a telecommunication system module that one or more of adjusts an amplitude or duration of a syllable to correct or improve the pronunciation of a mispronounced word.
According to a more specific exemplary embodiment, an automated telecommunication system adjunct performs the following:
(1) Encodes the received speech digitally, using a technique that permits the duration of distinct speech events, such as syllables, to be identified and represented as a specific, adjustable speech production parameter. Suitable speech encoding techniques include the aforementioned LPC, CELP, and the like.
(2) Detects that language A is being spoken. Automatic language identification techniques that are well known can be used for this step. Additionally, a repository can store information regarding which words, based on the language that is being spoken and the native language of the speaker, have a certain predisposition to mispronunciation.
(3) Detect that the person who is speaking language A is actually accustomed to speaking language B. Again, automatic accent identification techniques that are well known can be used with the systems, methods, and techniques disclosed herein.
(4) Use a knowledge of language A's and language B's pronunciation patterns and vocabularies to detect when a word in language A has been spoken with incorrect syllable duration because the pronunciation patterns of language B were applied inappropriately.
(5) Adjust the duration parameters associated with the misspoken syllable, lengthening or shortening the syllable to match the duration appropriate for language A. Optionally, the amplitude associated with the misspoken syllable thereby also assisting with matching the duration appropriate for language A.
(6) Use the modified speech product parameters to regenerate and present speech with the correct syllabic timing to the listener.
In addition to the above exemplary embodiment, the techniques disclosed herein can further include checks to confirm that the modifications in steps 4 and 5 above would be sensible.
More specifically, a first check could include determining whether the utterance, without modification, is a legitimate word in language A. A second check could include determining whether the utterance, if modified, would be a legitimate word in language A. A third exemplary check could determine whether the utterance is a known, common mispronunciation of a legitimate word is language A by people who are accustomed to speaking language B. A fourth exemplary check would determine whether the utterance that would be produced by step 5 above might be an inappropriate word or phrase in language A, e.g., an utterance that would be interpreted as rude or offensive.
Based on the above checks, a decision could be made to skip step 5.
In accordance with another exemplary embodiment, for step 5, a partial, rather than full adjustment, of the syllable could be performed such that the duration error is reduced but not eliminated.
In accordance with another exemplary embodiment, real-time visual feedback could be provided to one or more of the talker and listener to indicate when the voice stream has been modified.
In accordance with another exemplary embodiment, one or more of the parties, such as the listener, could be provided with an appropriate interface that allows them to enable, disable, or adjust the syllable-modification procedures.
In accordance with another exemplary embodiment, and in addition to unidirectional processing, i.e., processing person A's speech to person B, an exemplary implementation could support bi-direction processing, i.e., person A's speech to person B and person B's speech to person A.
In accordance with yet another exemplary embodiment, the speaker's original unmodified speech and modified speech could be simultaneously provided to a listener via separate audio channels and/or via separate audio transducers at the listener's location. The listener could monitor both simultaneously or choose the signal that sounds best at that point in time. Such a configuration might also be helpful if there are multiple listeners at multiple locations, each with his or her own listening preferences. For example, the modified, or unmodified, speech could be presented in a second channel of information, such as a whisper channel, and this could prove especially useful for calls that are recorded such that both the original verse the modified call is maintained.
In accordance with yet another exemplary embodiment, the techniques disclosed herein may also be useful in voice messaging systems, where the system could process messages to make it easier for the mailbox owner to understand what was said.
These and other advantages will be apparent from the disclosure contained herein. The above-described embodiments and configurations are neither complete nor exhaustive. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
As used herein, “at least one”, “one or more”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together.
BRIEF DESCRIPTION OF THE DRAWINGS
The exemplary embodiments of the invention will be described in detail, with reference to the following figures, wherein:
FIG. 1 illustrates an exemplary communication enhancement system;
FIG. 2 is a flowchart illustrating a method for enhancing communication; and
FIG. 3 is a flowchart illustrating in greater detail method of enhancing communication.
DETAILED DESCRIPTION
Some embodiments will be illustrated below in conjunction with an exemplary communication system. Although well suited for use with, e.g., a system using switch(es), server(s) and/or database(s), the embodiments are not limited to use with any particular type of communication system or configuration of system elements. Those skilled in the art will recognize that the disclosed techniques may be used in any communication application in which it is desirable to provide enhanced understandability of one party by another.
Referring initially to FIG. 1 an exemplary communication environment 1 will be described in accordance with at least some embodiments. The communication system comprises a communication network connecting a plurality of communication devices optionally to, for example, a conference bridge.
In one embodiment, the communication system may include a switch that may include a private branch exchange (PBX) system or any similar type of switching system capable of providing a telephone service to one or more entities such as an enterprise associated with the switch. The switch may be one of a number of known exchange systems including, but not limited to, Private Automated Branch Exchange (PABX), Computerized Branch Exchange (CBX), Digital Branch Exchange (DBX), or Integrated Branch Exchange (IBX). The switch may also comprise a switching fabric that provides for the connection of multiple endpoints such as communication devices associated with the conference participants, servers, and databases. The switching fabric can provide the functionality to direct incoming and/or outgoing calls to various endpoints and further provides for conferencing capabilities between endpoints.
The communication devices associated with the participants may be packet-switched or circuit-switched and can include, for example, IP hardphones such as the Avaya Inc.'s, 4600 Series IP Phones™, IP softphones such as Avaya Inc.'s, IP Softphone™, Personal Digital Assistants or PDAs, Personal Computers or PCs, laptops, packet-based H.320 video phones and conferencing units, packet-based voice messaging and response units, packet-based traditional computer telephony adjuncts, and conventional wired or wireless telephones.
FIG. 1 illustrates an exemplary communications environment 1 according to an exemplary embodiment. The communications environment 1 includes a normalization system or adjunct 100 , and one or more endpoints, such as endpoint A 200 and endpoint B 300 . Associated with each endpoint can be an optional feedback/input module, such as feedback/input modules 210 and 310 . The various endpoints are connected via one or more networks 10 , and links 5 and 7 , with link 7 being for example of an alternative communication path.
The endpoints can be any communications endpoint, such as a phone, speaker phone, microphone, multimedia endpoint, or the like, which is capable of communicating over one or more networks 10 such as a public-switch telephone network, a packet-switch telephone network, VOIP network, SIP-enabled network, or in general any communications network utilizing any one or more communications protocols.
The normalization system or adjunct 100 includes an analysis module 110 , a profile module 120 , controller 130 , memory 140 , storage/buffer 150 , duration/amplification modification module 160 , language detection module 170 , distinct speech event recognition module 180 , coding and compression module 190 and repository 105 .
In an exemplary operational mode, a normalization system 100 , in cooperation with the analysis module 110 , receives speech from one or more endpoints. Next, and in cooperation with the distinct speech event recognition module 180 , distinct speech events are detected. This is accomplished by encoding received speech and using a technique that permits the duration of distinct speech events, such a syllables, to be identified and represented as a specific, adjustable speech production parameters. Examples of these types of techniques include LPC and CELP as discussed above. Once the received speech is encoded, the identified distinct speech events are represented as specific, adjustable speech production parameters.
In cooperation with the language detection module 170 , and repository 105 , the analysis module 110 , cooperating with one or more of the profile module 120 , controller 130 , memory 140 , and storage/buffer 150 determines the language being spoken. In addition, the “native” language of the speaker can also be detected. This can be done, for example, in real-time on the received speech or, alternatively or in addition, retrieve the profiles stored in the profile module 120 . This profile can be associated with an endpoint and/or a person based on one or more identities, such as caller ID information, or information received from the person via the feedback/input module.
The analysis module 110 , cooperating with the repository 105 , then utilizes the knowledge of the language being spoken and the native language of the speaker to detect when a word or words in the language being spoken have incorrect syllable duration because the pronunciation patterns of the “native” language were applied inappropriately. Once these one or more incorrect syllable durations have been identified, and in cooperation with the duration/amplification modification module 160 , controller 130 , memory 140 , and storage/buffer 150 , one or more of the duration and amplitude parameters associated with the misspoken syllable are adjusted to one or morel of lengthen, shorten, emphasized, deemphasized, or otherwise adjust as appropriate in an attempt to align the misspoken word with the correct pronunciation of that word.
Once these one or more parameters have been adjusted, this modified speech product is used as the basis of a regenerated speech product that can then be presented with the correct or more correct syllabic timing/emphasis to a listener. In accordance with one exemplary embodiment, this modified speech product is provided on the normal communication channel, as an alternative to the actual speech spoken by the speaker. In accordance with another exemplary embodiment, this modified speech product is provided on alternative communication path 7 such as via a whisper channel to the listener. The controller 130 , cooperating with the input module 210 / 310 is able to allow the user to select various options regarding how the normalization system operates. For example, a user can select whether they would like the normalization system to be turned on or off, they can set up delivery options, e.g., to hear the modified speech on a whisper channel, to have the modified speech on the main channel, and the original speech on a whisper channel, only hear the modified speech, or the like. In addition, the user can select how to handle the various streams, such as recording of one or more of the original or modified speech streams as well as optionally saving meta information about the processing performed by the duration/amplification modification module.
In greater detail, the adjusting of the parameters associated with the misspoken syllable can be based on a number of criteria. For example, and in cooperation with the repository 105 , after the adjustment is made a determination can be made whether the utterance, without modification, is a legitimate word in the spoken language. For example the repository 105 can be queried, and more particularly, the dictionary and pronunciation rules therein, to determine if the word is legitimate. In addition, a determination can be made whether the utterance, if modified, is a legitimate word in the spoken language in the same manner.
In even greater detail, the repository 105 can be queried to determine if the utterance is a known, common mispronunciation of a legitimate word in the spoken language by people who are accustomed to speaking the “native” language. For example, the normalization system 100 can a mask this data by comparing numerous conversations between numerous participants to one or more portions of information being logged and stored in the repository 105 to optionally enhance the performance and accuracy of the normalization system.
As another check, the duration/amplification modification module 150 can cooperate with the repository 105 to determine whether the utterance that would be produced by the duration/amplification modification module 160 might be an inappropriate word or phrase in the spoken language. For example, if an utterance could be interpreted as rude or offensive, the analysis module 110 could one or more of further modify, delete, and provide information to the speaker about that particular utterance. For example, if it is determined that the utterance would be interpreted as rude or offensive, real-time feedback could be provided to the speaker via the input module indicating their mispronunciation of the word could cause problems.
In accordance with an additional or alternative exemplary embodiment, the duration/amplification modification module could make a partial rather than full adjustment to a syllable such that the duration error is reduced but not eliminated.
In a similar manner, feedback can also be used to optionally provide information to the speaker and/or listener to indicate when the voice stream being presented has been modified. This can again be provided via the feedback/input module 210 / 310 in one or more of an audible, visual, graphical, multimedia-based or comparable notification technique.
As previously discussed, this feedback/input module could also be used to optionally allow a party to enable, disable, or otherwise adjust the syllable modification techniques performed by the normalization system 100 . For example, an interface can be provided that allows a user to adjust the “aggressiveness” or the “corrections” made by the normalization system 100 as well to modify how the modified speech and/or original speech are delivered. This could be especially useful in situations where both the original and modified speech need to be preserved. In this example, both the modified and the original speech could be present and/or saved on different channels, such as via communications link 5 and the alternative communication path 7 .
One of the benefits of using LPC and CELP by the duration/amplification modification module 160 is that the amount of time a syllable spends in a gate is varied, with the net effect being the lengthening or shortening of a syllable, without causing a pitch shift. This in combination with optionally adjusting the amplitude of the syllable can be utilized very effectively to correct mispronunciation errors, such as “orenji” as discussed above.
FIG. 2 outlines an exemplary method of operation of a normalization system or adjunct. In particular, control begins in step S 200 and continues to step S 210 . In step S 210 , speech is received and encoded. Next, in step S 220 , distinct speech events are identified. Then, in step S 230 , the distinct speech events are represented as specific, adjustable speech production parameters. Control then continues to step S 240 .
In step S 240 , the language being spoken is detected. Then, in step S 250 , the “native” language of the speaker is one or more of detected or retrieved from, for example, a profile associated with the speaker. Control then continues to step S 260 .
In step S 260 , knowledge, such as pronunciation patterns and vocabularies, of the language being spoken and the “native” language of the speaker are utilized to detect when one or more words in the language being spoken have an incorrect syllable duration because the pronunciation patterns of the “native” language were applied inappropriately to the spoken language. Next, in step S 270 , one or more of the duration and amplitude parameters associated with the misspoken syllable are adjusted to one or more of lengthen, shorten, emphasized, or deemphasized as appropriate to correct the incorrect syllable duration for the language being spoken. Then, in step S 280 , the modified speech product parameters are used to regenerate and present corrected speech that has the modified syllabic timing/emphasis for presentation to one or more listeners. Control then continues to step S 290 where the control sequence ends.
FIG. 3 illustrates in greater detail steps S 260 -S 280 . More specifically, control begins in step S 300 and continues to step S 310 . In step S 310 , a determination is made whether the utterance, without modification, is a legitimate word in the spoken language. This can be done by comparing the utterance with a dictionary and optionally one or more pronunciation rules. Next, in step S 320 , a determination can be made whether the utterance, if modified, would be a “more legitimate” or legitimate word in the spoken language. Again, this can be done with a comparison to one or more of a dictionary and pronunciation rules that can be stored in, for example, a repository.
Then, in step S 330 , a determination can be made if the utterance is a known, common mispronunciation of a legitimate word in the spoken language by people who are accustomed to speaking “native” language. Again, this can be done by a comparison of the utterance to a word stored in the repository. Control then continues to step S 340 .
In step S 340 , a determination can optionally be made whether the utterance would be an inappropriate word or phrase in the spoken language. If this is the case, feedback can optionally be immediately relayed to the presenter indicating that their pronunciation is inappropriate, which may lead to problems. Control then continues to step S 350 .
In step S 350 , and instead of making a full adjustment to a syllable, a partial adjustment can optionally be made such that the duration error is reduced, but not eliminated. Next, in step S 360 , and as eluded to above, optional feedback can be provided to one or more of the speaker and listener to indicate, for example, when the voice stream has been modified. As will be appreciated, this can be provided back to the speaker, to the listener, or to both.
An optional exemplary step S 330 allows one or more of the parties to enable, disable, or adjust the modifications made by the normalization system. For example, a party can be allowed to turn on, turn off, and/or adjust the “aggressiveness” with which the normalization system is applying its syllabic modification techniques. Moreover, in step S 380 users can optionally be provided with the ability to modify delivery modification options. For example, a user can select which one or more audio streams, e.g., original, modified, or both they would like to receive. For example, in a stereo environment, a user may elect to receive the original version in channel A and the modified version in channel B. In another exemplary embodiment, the user may want to receive the modified version, with the original version being presented in a whisper channel. In yet another exemplary embodiment, the user may want to receive the modified speech, but have the original recorded. In yet another exemplary embodiment, both the original and the modified speech could both be recorded or, for example, archival purposes. As will be appreciated, a device associated with the input can be utilized to receive various inputs from a listener that allows them to modify exactly how they would like to hear one or more of the original and modified speech of a speaker. Control then continues to step S 390 where the control sequence ends.
In accordance with another exemplary embodiment, it should appreciated that the techniques disclosed herein are not limited to two parties, but can be extended to multiparty calls. In this example, it may be appropriate to utilize the techniques herein for only a portion of the communications channels in that some of the speakers may be speaking their native language, while others may be speaking in a language other than their native language.
Another optional feature is to utilize a profile, and in cooperation with a profile module 120 , have this profile cooperate with the duration/amplification modification module 160 correct commonly mispronounced words by a party. For example, the profile module 120 can store a directory of words that are always misspoken by a particular person. The duration/amplification modification module 160 , knowing that a particular person historically always mispronounces a particular word, can use this historical information to assist with dynamically correcting the mispronunciation in real or near real-time. Utilizing this stored historical information can also help reduce the computational burden placed on the normalization system in that if the modified word has already been vetted to be a legitimate word, is in the dictionary, does not violate any pronunciation rules, and is not interpretable as rude or offensive, then clearly steps could be bypassed by the normalization system each time that mispronunciation occurs.
In accordance with another exemplary embodiment, and again to further assist reducing the computation burden on the system, buffer 150 can be utilized such that words identified as misspoken in the same conversation can have the corrected version retrieved from the buffer and presented as the modified utterance to the other participant(s). Thus, instead of having to perform a majority of the steps enumerated above, once the misspoken word is (again) detected, the analysis module 110 can immediately substitute the modified version of the utterance as stored in the buffer.
The various embodiments include components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.
The foregoing discussion has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as separate preferred embodiments.
Moreover, though the description of the invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the disclosure, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.
While the above-described flowcharts have been discussed in relation to a particular sequence of events, it should be appreciated that changes to this sequence can occur without materially effecting the operation of the invention. Additionally, the exact sequence of events need not occur as set forth in the exemplary embodiments. The exemplary techniques illustrated herein are not limited to the specifically illustrated embodiments but can also be utilized with the other exemplary embodiments and each described feature is individually and separately claimable.
The systems, methods and protocols described herein can be implemented on a special purpose computer in addition to or in place of the described communication equipment, a programmed microprocessor or microcontroller and peripheral integrated circuit element(s), an ASIC or other integrated circuit, a digital signal processor, a hard-wired electronic or logic circuit such as discrete element circuit, a programmable logic device such as PLD, PLA, FPGA, PAL, a communications device, such as a phone, any comparable means, or the like. In general, any device capable of implementing a state machine that is in turn capable of implementing the methodology illustrated herein can be used to implement the various communication methods, protocols and techniques disclosed herein.
Furthermore, the disclosed methods may be readily implemented in software using object or object-oriented software development environments that provide portable source code that can be used on a variety of computer or workstation platforms. Alternatively, the disclosed system may be implemented partially or fully in hardware using standard logic circuits or VLSI design. Whether software or hardware is used to implement the systems in accordance with this invention is dependent on the speed and/or efficiency requirements of the system, the particular function, and the particular software or hardware systems or microprocessor or microcomputer systems being utilized. The communication systems, methods and protocols illustrated herein can be readily implemented in hardware and/or software using any known or later developed systems or structures, devices and/or software by those of ordinary skill in the applicable art from the functional description provided herein and with a general basic knowledge of the computer and communication arts.
Moreover, the disclosed methods may be readily implemented in software that can be stored on a non-transitory storage medium, executed on a programmed general-purpose computer with the cooperation of a controller and memory, a special purpose computer, a microprocessor, or the like. In these instances, the systems and methods of this invention can be implemented as program embedded on personal computer such as an applet, JAVA® or CGI script, as a resource residing on a server or computer workstation, as a routine embedded in a dedicated communication system or system component, or the like. The system can also be implemented by physically incorporating the system and/or method into a software and/or hardware system, such as the hardware and software systems of a communications device or system.
It is therefore apparent that there has been provided, in accordance with the present invention, systems, apparatuses and methods for enhanced communications understandability. While this invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, it is intended to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of this disclosure. | A very common problem is when people speak a language other than the language which they are accustomed, syllables can be spoken for longer or shorter than the listener would regard as appropriate. An example of this can be observed when people who have a heavy Japanese accent speak English. Since Japanese words end with vowels, there is a tendency for native Japanese to add a vowel sound to the end of English words that should end with a consonant. Illustratively, native Japanese speakers often pronounce “orange” as “orenji.” An aspect provides an automatic speech-correcting process that would not necessarily need to know that fruit is being discussed; the system would only need to know that the speaker is accustomed to Japanese, that the listener is accustomed to English, that “orenji” is not a word in English, and that “orenji” is a typical Japanese mispronunciation of the English word “orange.” | 6 |
PRIORITY
This application claims the benefit of U.S. Provisional Application Ser. Nos. 60/615,684 and 60/615,759, both filed on Oct. 5, 2004, the contents of which are incorporated by reference herein in their entirety.
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to biomedical electrodes attached to the body of a human being or an animal. These electrodes, often referred to as dispersive electrodes, return electrodes, grounding pads, patient plates or Bovie pads, are used to deliver or receive current from the body during various electrosurgical procedures such as, but not limited to, general surgery, arthroscopy, laproscopy, gastroentrology, gynecology, urology, ENT, cardiology, spinal and cosmetic surgery.
BACKGROUND OF THE INVENTION
Biomedical electrodes are used in a variety of medical and veterinary applications and are configured to operate according to the amplitude, duration, type and direction of the current flowing into or out of the body of the subject. In monopolar electrosurgery, as in all situations where electrical current is flowing, a complete circuit must be provided to and from the current source. For example, a current that enters the body at the location where the electrosurgical procedure is being performed leaves it in another place and returns to the electrical generator. It is clear that when current of enough intensity to deliberately cut, ablate, heat or stimulate is brought into contact with the body of a subject in one location, great care must be taken to ensure that unintentional damage is not done to the subject at the place where the current is leaving the body. An electrode attached to the subject's body performs the task of collecting the current safely. This electrode is supposed to perform this task by providing a large surface area through which the current can pass. When the collected current is spread over a large area, the current density is low enough so as to render the process harmless to the subject. This electrode is often referred to as a dispersive electrode, return electrode, electrosurgical pad, electrosurgical plate, grounding pad subject plate, subject return electrode or Bovie plate. These return electrodes are used in many medical procedures, including, but not limited to, monopolar electrosurgery, arthroscopy, urology, gynecology, laproscopy, open surgery, cardiac defibrillation, heating and many others. The electrodes are available commercially from such vendors as ConMed Corp., Valleylab (div of Tyco), Minnesota Mining and Manufacturing (3M), Erbe, Bovie Medical, Megadyne as well as others.
In many monopolar electrosurgical applications, radio frequency (RF) power is delivered to the field of surgery by a surgical electrode or probe. The probe strongly focuses the RF current/power in a small contact area in the vicinity of the metallic tip of the probe and in the tissue in contact with it (often less than few square millimeters). As a result, the desirable effect of heating, coagulation, ablation, cutting etc. takes place in this small area. The probe is connected to the “output” of the electrical generator by an insulated wire which, in many cases, goes through the subject body. The return current conductor is connected to the “ground” or “return” terminal of the generator through a large area electrode placed on the surface of the subject body. This electrode collects the current induced in the subject body.
In electrosurgery, it is essential that the RF power be strongly focused in the immediate vicinity of the location where the desired procedure is performed. Not less important is a strong defocusing or dispersion of the electrical current beyond the target point of the surgery. This strongly dispersed current, or “return current”, should go through the subject body without harmful effects; for example, heating above a safe level can possibly lead to burns. Eventually all current is collected by the large area (on the order of few hundred square centimeters) electrode (i.e., the dispersive electrode) attached to the surface of the subject body and returned to the electrical generator by an insulated “ground” wire. Peak current density collected by the return electrode is affected by the current distribution over the area of that electrode. The distribution of the “return” current over the area of the dispersive electrode is affected, among other things, by the location of the surgical area with respect to the location of the dispersive electrode, the dispersive electrode area, and by the physical size of the subject's body between these areas. Many cases of the calculated non-uniform current density distribution under biomedical electrodes are described in the literature (e.g., Vessela Tz Krasteva et al., “Estimation of the current density distribution under electrodes for external defibrillation”, BioMedical Engineering Online Journal, 16 Dec. 2002). Subject's safety is achieved by dispersing the “return” current over the large surface area of the return electrode.
Accordingly, it is extremely difficult, but very important, to ensure that the current density distribution in the proximity of the dispersive electrode be as uniform (homogeneous) as possible. Since the return electrode is usually placed on the surface of subject's body, the cross section of the return current channel (i.e., the physical size of the subject's body) is sharply and abruptly decreased to the size of the dispersive electrode itself at the position where the electrode is attached to, and in contact with, the body. As a result, the dispersive electrode always compresses, or focuses, the return current in its vicinity. In all cases, unless special corrective measures are taken, the collected current distribution over the area of the return electrode is different from the desired uniform, smooth distribution. The result is that an extremely non-homogeneous distribution exists on the surface of the dispersive electrode, and in the proximity of the electrode below its surface (in the subject's body). Often current density near the outer edge of the dispersive electrode may be 10 times higher than at the center. In practice, this means that undesirable heating of the subject's body is strongly enhanced in the proximity of the outer edge of the dispersive electrode; this is often called the “edge effect”. The tendency of electrosurgical return current to cluster and generate heat in the vicinity of the corners and the outer edges of the return electrodes has been a long-standing design/safety problem that can lead to subject burns. Because of this inefficient current distribution, safety consideration have dictated that:
(a) Return electrodes must be much larger than necessary so as to provide homogeneous current distribution (i.e., the physical area of the electrode must be much larger than its “effective” area), and (b) Most return electrodes must be positioned on the subject body with the long edge facing the surgical site to avoid burns.
Dispersive electrodes are also used for external defibrillation. Defibrillation of the heart is a widespread and well-established procedure for resuscitation of cardiac arrest victims. The most accessible approach for electrical cardiac therapy is via external electrodes, placed on selected locations on the surface of the thorax. The electrodes have a large surface area, and provide the high, and supposedly uniform, current density distribution in the heart needed for excitation of most myocardial cells, thus forcing them to return to normal rhythm. However, it has been reported that with conventional electrodes about 25% of the myocardium volume could be subject to current densities more than four times higher than the threshold density. Another aspect of the problem is the predominance of high current density along the perimeter of defibrillator electrodes applied on human skin (same edge effect discussed earlier). This can lead to unwanted damage and even severe skin burns or electroporation.
As current density is highly non-uniform across the return electrode, and is very high close to its edge, there is a risk of burns due to the tendency of the current and heat to cluster at the edges of the return electrode. Therefore, for safety reasons the pads are made much larger than needed. However, the larger the pad, the more difficult it is to place on subjects with limited muscle tissue, especially the elderly, babies and children. Suitable pad placement on burn victims and subjects with implants, excessive hair, scar tissue or skin problems has also proven to be difficult.
Accordingly, it is readily apparent that the art needs biomedical return electrodes capable of reducing the “clustering” of current at the edges of the electrode. The present invention solves the problems discussed above by providing a novel biomedical return electrode in which the current density distribution in the proximity of the dispersive electrode is much more uniform. In particular, the electrodes of the present invention are capable of altering and greatly improving the uniformity of current density profile in the proximity of the interface between the electrode and mammalian tissue. As a result, the chance for burns and other tissue damage to the skin as well as discomfort experienced by subject during or after usage is reduced.
In sum, the present invention provides a biomedical dispersive electrode which favorably redistributes the current in the subject's body in the proximity of the interface between the electrode and subject tissue, increases subject safety, and reduces the chance for burns and other tissue damage as well as discomfort experienced by subjects during or after usage. This new approach makes it possible to substantially reduce the size of the electrode, without compromising subject safety. Smaller size will improve the ease of use required in subject care environment.
SUMMARY OF THE INVENTION
The present inventors discovered that reshaping and splitting the electrically conducting component into multiple components of various, specially designed configurations resulted in a favorable current redistribution in the subject body. This goal is achieved since the combination of multiple electrically conducting components of the device, the conductive dielectric, as well as the electrical properties of the subject tissue are all integrated as part of an equivalent electrical circuitry. With proper design, discussed in detail below, the result is that the current distribution in the subject body can be “tailored” as needed for a specific use or application. In some applications, a favorable condition is created by a homogeneous current density distribution. In other applications, a specially tailored non-homogeneous current density can be advantageous.
The electrical circuitry that allows the favorable redistribution of the current in the subject body can be composed of passive, active, lumped, distributed, internal or external components, and includes the tissue of the subject.
Accordingly, in the biomedical electrode of the present invention the current distribution over the electrode is controlled in a unique way by using an advanced electrode design. The return current distribution in the proximity of the electrode is affected by the voltage (active, or passive) distribution applied along the surface of the electrode. Herein, the term “passive” means that the desired voltage is self-generated by the current flowing through the return electrode assembly in contact with the subject. Conversery, the term “active” means that the voltage is supplied externally. For illustration purposes, consider the case where the return electrode is not a solid material of high conductivity, like metal, but rather consists of multiple metallic components, or segments, electrically connected in a defined way according to the principles of this invention. Properly chosen passive or active voltage distribution can be used to “tailor” the current density distribution in a desired way, e.g., to redistribute current nearly homogeneously over the surface of the return electrode. In the context of the present invention, it is important to properly design a favorable voltage distribution. Non-favorable voltage distribution in a multi component dispersive electrode can substantially worsen, instead of improve, the current density distribution compared to a commonly used dispersive electrode.
As indicated, smoothing the current distribution over the surface of the biomedical return electrode can be achieved by creating a favorable voltage distribution. Herein, the present invention provides three different approaches for the implementation of these concepts: category (1)—passive resistive-capacitive dividers; category (2)—passive resistive-inductive dividers, and category (3)—active voltage distributors. The implementation of these three principles, or combinations of these principles, will result in many versions of electrodes according to the principles of this invention, as will be described below.
Accordingly, following the passive resistive capacitive divider approach of category (1), the present invention provides a metallic electrode that, instead of being a single conducting plate (or two in the case of a split-pad), is mechanically and electrically divided into multiple elements, such as rings or other combinations of metallic electrodes (i.e., a multi element/segment return pad). These conductive elements or conductors are electrically incorporated into a voltage divider in the form of distributed or lumped resistors, capacitors, or combinations thereof, including a conductive dielectric adhesive (sometimes referred to as a gel) as a resistive-capacitive element. Note that conductive dielectric materials of various kinds are well known for those skilled in the art, and are widely used in order to create good contact between the biomedical electrode and the body of the subject.
In use, a return wire (ground/neutral) is connected to one or more of the central elements of the electrode. In the present invention, the voltage induced on the periphery elements increases as you move farther away from the center element. A resistive-capacitive voltage divider according to the principles of this invention will redirect the return current towards the center of the electrode, thus creating the desired more uniform and homogeneous current distribution over the entire area of the biomedical electrode.
The resistive-capacitive connection can be provided, for example, by appropriate use of distributed-circuit-elements, such as conductive/dielectric layers (conductive gel or some other conducting material including metallic foil) placed on the subject side or the opposite side of the dispersive pad; by appropriate use of lumped (discrete) circuit elements; or by combinations of these approaches. Note that the subject tissue itself can be described as a conductive dielectric, and is “included” into the equivalent electrical circuitry of the voltage divider.
Many variations are possible according to the principles of this invention, and illustrative examples are described in detail below. All are designed to create more optimal voltage and current distribution in the subject body and therefore increase subject safety. Examples of dispersive electrodes according to the present invention include, but are not limited to single and split-pads; circular and non-circular; symmetric and non symmetric; disposable and non-disposable.
Note, herein a dispersive electrode is referred to as a “split-pad” when it constructed in a way that allows for the measurement of the quality of contact impedance between the pad and the patient body. Alternatively, when the dispersive electrode is not constructed in such a way, it is referred to as non-split or single pad. A split-pad can be implemented by adding an additional conducting electrode, or by cutting the conducting electrodes of a non-split pad (thus doubling the number of conducting electrodes). In the figures, the non-split pads are often shown schematically with a conducting wire connection, while the split-pads are often shown with two conducting wires.
In another embodiment, the present invention provides a dispersive electrode that facilitates the creation of a favorable voltage distribution in the subject's body below the conducting element of the electrode, rather than on the electrode itself. This is done by using a continuous metallic electrode (non-segmented) and controlling the thickness and or the conductivity of the conductive dielectric layer situated between the metallic component of the dispersive pad and the subject's skin.
Following the resistive-inductive divider approach of category (2), the present invention provides a dispersive electrode comprising, for example, a return electrode shaped in the form of flat, multi-turn spiral. This construction has intrinsic self-inductance that can function as an inductive voltage divider. When current is collected on this style of dispersive electrode, a voltage distribution is self-generated along the surface of the electrode (between the turns of the spiral). When the ground wire is connected to one or more electrodes at the center of the spiral, the voltage increases from the center to the edge of the spiral. This voltage increase redistributes the return current away from the edge and toward the center, thus creating a more homogeneous current distribution.
Many variations to the dispersive electrodes designed according to the principles of (2) above are possible. For example, the electrode may comprise a solid central area surrounded by a spiral in the periphery. Other variations include, but are not limited to, single and split-pads; circular and non-circular; symmetric and non-symmetric; disposable and non-disposable, spiral; non-spiral (ring) and more. The resistive-inductive connection can be provided, for example, by appropriate use of distributed circuit elements like conductive dielectric layers (conductive gel or some other conducting material including metallic foil), or lumped (discrete) circuit elements placed on the subject side or the opposite side of the dispersive pad; or by combinations of these approaches. Furthermore, the lumped element approach can be used effectively with the two other categories according to the principles of this invention (namely the resistive-capacitive and the active).
Following the active voltage distribution approach of category (3), the present invention provides a dispersive electrode comprising an active voltage distributor. In this embodiment, the favorable voltage distribution on the return electrode is created by supplying voltages from external sources.
Accordingly, one aspect of the present invention involves the use of distributed, or lumped, resistive components, capacitive components, inductive components, or a combination thereof, to alter and greatly improve the uniformity of current density profile in the proximity of the interface between the electrode and mammalian tissue.
Another aspect of the present invention involves the selection of geometrical configurations, shapes and materials to alter and greatly improve the uniformity of current density profile in the proximity of the interface between the electrode and subject tissue.
Another aspect of the current invention involves dividing of the metallic, electrically conductive portion of the biomedical electrode into multiple conductive elements, in order to redistribute the current in the subject body.
Thus, it is an object of the present invention to provide a biomedical electrode, comprised of multiple electrical conductors in contact with a conductive dielectric material (conductive gel) that interfaces the subject for exchanging electromagnetic energy. The conductive dielectric preferably takes the form of a thin layer of variable geometry, including, but not limited to, circles, ellipses, polygons, and combinations thereof, both linear and non-linear. Furthermore, the outer edges of the conductive dielectric layer may comprise a series of curves or waves, having, for example, a sinusoidal configuration. Note, the outer edges of the conductive dielectric layer may extend beyond the perimeter defined by the electrical conductors.
Another object of the present invention is to provide a more universal biomedical electrode that can be used effectively and safely for large variety of subject population, such as babies; children; adults; the elderly; subjects with excessive hair, limited muscle tissue, scar tissue or skin problems, and burn victims that normally proved very difficult. An advantage of this aspect is the reduction in the required inventory of electrodes in medical care facilities.
Another object of the present invention is to provide a biomedical electrode having a small size. Because of its ability to disperse the current more uniformly, most of the area of an electrode of the present invention is utilized effectively. At present, return electrodes must be much larger than necessary if the current distribution is to be made homogeneous (in other words, the “effective” area is much larger than its physical area). Electrodes according to the principles of this invention are characterized by an “effective area” that is roughly equal to the geometrical area of the electrode.
Another object of the invention is to provide a biomedical electrode for electrosurgical applications that has a maximum rise in temperature of less than 6° C. from beginning of use with an electrosugical generator, when methodology according to industry testing standard AAMI Standard HF18 (American National Standard for Electrosurgical Devices, Maximum safe temperature rise).
Another object of the invention is to provide a biomedical electrode characterized by a more uniform temperature distribution profile as compared to electrodes based on known art.
An advantage of the biomedical electrode of the present invention is its ability to reduce the chance for burns and other tissue damage to the skin during or after usage in electrosugery.
Another advantage of the biomedical electrode of the present invention is its ability to reduce the pain, irritation and discomfort experienced by subjects during and after removal of the electrode from the subject skin because the electrode is generally smaller than electrodes based on known prior art.
Another advantage of the biomedical electrode of the present invention is its ability to be positioned on the subject body without special regards to orientation relative to the surgical site.
Accordingly, in one preferred embodiment, the dispersive electrode of the present invention is comprised of an electrically non-conductive backing, and at least one, and in many cases more than one, conductive plates with a configuration and shape as shown, for example, by some of the embodiments of this invention. The plates will most often be adhered to the electrically non-conductive backing. In addition, a layer of conductive dielectric material, such as a conducting gel, is preferably disposed between the conductive plates and the surface of the electrode in contact with the body of the subject. A film of conductive adhesive may be present in contact with the conductive plate(s) and the gel like material. In some cases, it may be advantageous to place the conductive dielectric material on both sides of the conductive plates. As noted above, in some embodiments, the conductive dielectric gel-like material may extend beyond the outer edges of the metallic plate(s). Note, the outer edges the metallic plates may comprise a curvilinear or waved-edge configuration.
Another aspect of this invention involves the use of electrically insulative (non-conductive) material for the backing. The electrically non-conductive backing material is preferably comfortable to the various contours of the subject body. Many materials can be used for this purpose, as will be apparent to those skilled in the art.
For electrosurgical applications, the conductive adhesive can serve three purposes. First, it serves to adhere and create intimate contact between the biomedical electrode and the body of the subject. Second, it provides for transfer of the electrosurgical current into and out of the subject body. Third, it provides for transfer of the current in a way which permits the electrode to register an alarm condition (CQM) if a portion of the electrode unpeels from contact with the body of the subject.
All the advanced pads according to the principals of this invention are characterized by high efficiency (i.e., the physical area is approximately equal to the effective area), high current carrying capabilities and small surface area as compared to standard electrosurgical pads. As such, the pads can be used by adults, children and babies while maintaining subject safety.
While the invention has been described with reference to a number of specific embodiments, it will be appreciated that the description is illustrative of the invention and is not constructed as limiting of the invention. Various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims. For example, the pads can take the shape of various geometries beyond those described in the figures; the edge of the conducting material can take the form of wiggles or corrugations both on the inside and outside, segmented electrode and segmented conductive dielectric with different electrical and thermal properties at each segment or section; as well as other forms without deviating from the scope of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration showing the calculated, highly non-uniform current density distribution over a conventional circular return electrode having an area of ˜80 cm 2 and that of an “ideal” return electrode.
FIG. 2 depicts an example of a prior art single (non-split) return electrode.
FIG. 3 depicts an example of an active voltage distributor return electrode according to the present invention.
FIG. 4 is a diagram of the electrical circuit of a passive capacitive voltage divider dispersive electrode according to the present invention.
FIG. 5 is a diagram of the electrical circuit of a passive resistive voltage divider electrode according to the present invention.
FIG. 6 is a diagram of the electrical circuit of a passive resistive-capacitive voltage divider according to the present invention.
FIG. 7 depicts an example of a split pad according to the principles of category (1) of the present invention (resistive-capacitive divider). A perspective view of a symmetric (circular), two-ring (three component), split return electrode is provided. The voltage induced on the periphery components increases as you move away from the center element, thus redistributing the return current towards the center of the electrode. Numerous other shapes, including, for example, elliptical, rectangular, square, square with rounded corners and wiggled or waved edges are contemplated by the present invention.
FIG. 8 depicts an example of a single (non-split) pad according to the principles of category (2) of this invention (resistive-inductive divider). A perspective view of a spiral, single (non-split) return electrode is provided. The voltage increases as you move away from the center, thus redistributing the return current towards the center of the electrode. Numerous other shapes, including, for example, elliptical, rectangular, square, polygonal, square with rounded corners and waved edges are contemplated by the present invention.
FIG. 9 provides top and cross-sectional views of another example of a resistive-capacitive divider electrode of the present invention, namely a circular two component (one central plate and one ring), single (non-split) pad.
FIG. 10 provides top and cross sectional views of another example of a resistive-capacitive divider electrode of the present invention, namely a two component (one central plate and one ring), split pad.
FIG. 11 provides top and cross sectional views of another example of a resistive-capacitive divider electrode of the present invention, namely a circular three component (one central plate and, two rings), split pad.
FIG. 12 provides top and cross sectional views of another example of a resistive-capacitive divider electrode of the present invention, namely a circular, three component (one central plate and, two rings), single (non-split) pad.
FIG. 13 provides top and cross sectional views of another example of a resistive-capacitive divider electrode of the present invention, namely a rectangular, two component (one central plate and one rectangular ring), split pad. Many other variations are contemplated, such as, multi-electrode and single (non-split) pads.
FIG. 14 provides top and cross sectional views of another example of a resistive-capacitive divider electrode of the present invention, namely an elliptical, two component (one central plate and one elliptical ring), split pad. Many other variations are contemplated, such as, multi-electrode and single (non-split) pads.
FIG. 15 provides a cross sectional view of another example of a resistive-capacitive divider electrode of the present invention, including a non-segmented return pad.
FIG. 16 provides a cross sectional view of another example of a resistive-capacitive divider electrode of the present invention, including a non-segmented return pad.
FIG. 17 provides a cross sectional view of another example of a resistive-capacitive divider electrode of the present invention, including a non-segmented return pad.
FIG. 18 provides a cross sectional view of another example of a resistive-capacitive divider electrode of the present invention, including a non-segmented return pad.
FIG. 19 provides a cross sectional view of another example of a resistive-capacitive divider electrode of the present invention, including a segmented return pad.
FIG. 20 provides a top view of a resistive-inductive divider electrode of the present invention, namely a single (non-split), single-spiral return electrode.
FIG. 21 provides a top view of another example of a resistive-inductive divider electrode of the present invention, namely a split, single-spiral return electrode.
FIG. 22 provides a top view of another example of a resistive-inductive divider electrode of the present invention, namely a split, double-spiral return electrode.
FIG. 23 provides a top view of another example of a resistive-inductive divider electrode of the present invention, namely a split, double-spiral return electrode.
FIG. 24 provides a top view of another example of a resistive-inductive divider electrode of the present invention, namely a split, single-spiral return electrode.
FIG. 25 provides a top view of another example of a resistive-inductive divider electrode of the present invention, namely a single, rectangular single-spiral return electrode.
FIG. 26 provides a top view of another example of a resistive-inductive divider electrode of the present invention, namely a split, rectangular double spiral return electrode.
FIG. 27 provides a schematic diagram for a system for active voltage distribution according to the present invention. Herein, a favorable voltage distribution on the return electrode is created by supplying voltages from an external source.
FIG. 28 is an illustration depicting the calculated current density distribution over a circular return electrode designed based on principles of known prior art, and that of a four component (one central plate and, three rings) return electrode according to the principles of this invention. Note that with the prior art pad, the current distribution is highly non-uniform and tends to cluster in the vicinity of the edge, but the distribution is much more uniform for a pad designed according to the principles of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The words “a”, “an”, and “the” as used herein mean “at least one” unless otherwise specifically indicated.
The biomedical electrodes of the present invention have both medical and veterinary applications. Accordingly, the term “subject” as used herein refers to both humans and animals, more preferably mammals.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.
Hereinafter, reference is made to the accompanying drawings which form part thereof, and in which is shown, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and is to be understood that other embodiments may be utilized, and that structural, logical and electrical changes may be made without departing from the spirit and the scope of the present invention. Referring now to the drawings, like elements are designated by like reference numerals when appropriate.
FIG. 1 shows, as an example, the calculated, highly non-uniform current density associated with a circular pad 1 having an area of about 80 cm 2 . The tendency of the return current to cluster, and heat the subject, at the edges of the return electrode (also known as “edge effect”) has been a long-standing problem that can lead to subject burns. This calculated “clustering” 2 is shown in the figure. Also shown as a dotted line, for illustration purposes, is a hypothetical, ideal, uniform current distribution 3 . To overcome the overheating in the areas of current “clustering”, the return electrodes must be much larger than necessary if the current distribution is to be made homogeneous.
FIG. 2 shows, for illustration purposes, a schematic perspective view of a conducting plate 5 of a single (non-split) return electrode 4 having a circular geometry based on known art. Also shown is the electrical wire 6 connecting the electrode to the ground, or neutral, of the electrical generator or to a sensing unit. For clarity, other elements needed for proper operation are not shown in this figure. Those elements and other features will become apparent in the discussion follows.
For illustration purposes only, FIG. 3 shows a schematic, perspective view of a four component (three rings and a central conducting plate) of a single (non-split) return electrode 7 according to the principles of active voltage distribution. The central conducting plate 8 is connected to the ground of the electrical generator through wire 6 . A conducting plate in the form of a ring 9 is connected to the external voltage source through electrical wire 11 . Another conducting plate in the form of a second conducting ring 10 is connected to an external voltage source through electrical wire 12 . In the case of externally generated active voltage distribution, the external voltage sources should be synchronized with the main electrical generator. Other electrode configurations are contemplated by the present invention. For example, the electrode may be provided with more or less conducting rings and segments. For clarity purposes, other elements required for proper device operation are not shown in this figure. These additional elements and other features will become apparent in the discussion follows.
FIG. 4 shows a schematic diagram of one half (around a line of symmetry) of the equivalent electrical circuit of a passive capacitive voltage divider (category (1)). Shown in this figure is a cutaway of a three-component geometry (two-rings and a conducting plate). The central conducting plate 40 , as well as the conducting rings 41 and 42 are attached to the subject tissue 43 through an interface, or intermediate layer, or field of conductive dielectric material 44 . In this example of a non-split pad, the device is connected to an external electrical generator through an electrical wire 6 . The capacitive elements 400 can be distributed or lumped.
FIG. 5 shows a schematic diagram of one half (around a line of symmetry) of the equivalent electrical circuit of a passive resistive voltage divider (category (1)). Shown in this figure is a cutaway of a three-component geometry (two-rings and a conducting plate). The central conducting plate 40 , as well as the conducting rings 41 and 42 are attached to the subject tissue 43 through a field of conductive dielectric, gel-like, material 44 . In this example of a non-split pad, the device is connected to an external electrical generator through an electrical wire 6 . The resistive elements 500 can be distributed or lumped, external or internal.
FIG. 6 shows a schematic diagram of one half (around a line of symmetry) of the equivalent electrical circuit of a combination passive capacitive-resistive voltage divider. Shown in this figure is a cutaway of a three-component geometry (two-rings and a conducting plate). The central conducting plate 40 , as well as the conducting rings 41 and 42 are attached to the subject tissue 43 through a field of conductive dielectric, gel-like, material 44 . In this example of a non-split pad, the device is connected to an external electrical generator through an electrical wire 6 . The capacitive 400 and resistive 500 elements can be distributed or lumped.
The embodiments shown in FIGS. 4 , 5 and 6 can be also be implemented as a split-pad version, which permits the electrode to register a detection system of a CQM alarm condition if a portion of the electrode unpeels from contact with the body of a mammalian subject. The conductor plates 40 , 41 , 42 are conveniently made of metal, preferably in the form of a foil. However, other conventional conducting, non-metal materials are also contemplated. In addition, although the figures depict a device that is cylindrically symmetric around the centerline, other embodiments are contemplated. For example, the geometries can be rectangular, elliptical, polygonal or many other shapes, both symmetric and non-symmetric, without deviating from the spirit of this invention.
As indicated, the conducting plates may be attached to the subject tissue 43 through an intermediate interface layer, or multiple layers, of a field of conductive dielectric material 44 . Many compositions for this material are known and available for use by people experienced in the art. Non-limiting examples useful in connection with the present invention include various compositions made by U.S.-based companies like ConMed, Tyco-Valleylab, Minnesota Mining and Manufacturing, Bovie Medical as well as European companies such as Erbe, as well as others in China and Korea. An important property of these conductive dielectric materials is their specific electrical resistivity (which is defined as the inverse conductivity). Some non-limiting examples of the specific electrical resistivity of various known and used material compositions 44 are given in Table 1. The field of conductive dielectric material, in a form of one or more intermediate interface layers, itself acts as the distributed element described in the equivalent circuit of FIGS. 4 , 5 , and 6 . In other cases, devices based on the principles of this invention can be used with or without additional lumped elements shown in the equivalent circuits described above. Furthermore, the embodiments of FIGS. 4 , 5 , and 6 may be modified to be category (2) electrodes simply by replacing the capacitive components with inductive components (lumped or distributes).
TABLE 1
Specific
Specific
Specific
Resistivity
Resistivity
Resistivity
at 60 kHz
at 200 kHz
at 500 kHz
Example
[Ohm · m]
[Ohm · m]
[Ohm · m]
1
5.3
5.5
5.1
2
160
130
98
3
15.1
16.2
16.1
4
3.1
3.1
3.1
5
4.8
4.8
4.7
6
2
2.1
2.2
Because of its electrical resistivity, the conductive dielectric material creates voltage distribution if electrical current is flowing through it, as is the case in electrosurgery. Also, this material dissipates electrical energy, meaning it converts current into heat or, in other words, the conductive dielectric material is electrically heated. Accordingly, it is sometimes also referred to as a dissipative material or lossy dielectric. Specific designs of devices based on the principles of this invention will take into account the specific properties of a conductive dielectric material 44 , and specific dimensions will therefore depend on the properties of the materials used, among other things.
Note that the range of useful electrical resistivity is typically 0.1-200 Ohm·m, more preferably 1-20 Ohm·m. The conductive dielectric can be solid or gel-like material can be used in the form of non-uniform thickness layer, or layers, of various geometries, as will be shown in some of the illustrative embodiments that follow.
FIG. 7 depicts a perspective view of a preferred embodiment of a dispersive pad 70 based on the principles of the present invention, category (1). It particularly shows a three-component (two-rings and central plate) split pad, where the gel-like material 44 is partly peeled off for better visualization of internal construction details. More specifically, the split inner conducting plates 71 , 72 , the split first conducting ring 73 and 75 , and the split second conducting ring 74 and 76 , all mounted on, or glued to, the pad backing material 78 suitable for protecting the device. The pad backing material 78 is electrically non-conducting. The two electrical wires, 79 , are each connected to the split inner conducting plates 71 and 72 . Note that only one wire is needed for a single, non-split pad, while two are needed for a split pad to form a connection to the electrical control unit, not shown. Note that for simplicity, a release liner, suitable for protecting the gel-like material during shipping and handling while releasing easily before the time of use, is not shown in FIG. 7 . The material 44 will be in contact with the mammalian skin, or tissue, during use.
FIG. 8 is a perspective view of yet another preferred embodiment of a dispersive pad 80 , based on the principles of the present invention category (2). It shows a spiral, single pad, where the gel-like material 44 is partly peeled off for better visualization of internal construction details. More specifically, the spiral conducting plate 86 mounted on, or glued to, the pad backing material 78 suitable for protecting the device. The pad backing material 78 is electrically non-conducting. The electrical wires, 6 , are connected to the center of the spiral, hidden from view in this figure. Note that only one wire is needed for a single, non-split pad. Also note that for simplicity, a release liner, suitable for protecting the gel-like material during shipping and handling while releasing easily before the time of use, is not shown in FIG. 8 . The liner is generally electrically non-conductive and can be made from any number of commercially available materials. The material 44 will be in contact with the mammalian skin, or tissue, during use.
FIGS. 9 , 10 , 11 , 12 , 13 and 14 illustrate four different illustrative examples of preferred embodiments according to the principles of this invention. For simplicity, the backing material 78 is omitted from these figures.
FIG. 9 shows both a bottom view and a cross sectional view YY of one preferred embodiment of a two component (one central conducting plate, one ring), single (non-split), dispersive pad based on the principles of category (1) according to this invention. The central conducting plate 90 and one conducting ring 92 are attached to the conductive material 44 which extends radially to, or beyond, the outermost radius of the conducting ring 92 . The conducting plate 90 is connected to the electrical generator (not shown) via an electrical connection 6 .
FIG. 10 shows both a bottom view and a cross sectional view YY of a split version of the single (non-split) dispersive pad shown in FIG. 9 , also based on the principles of category (1) according to this invention. In the split pad version, the central conducting plate 90 of FIG. 9 is split here into two halves 100 and 101 . The conducting ring 92 of FIG. 9 is split here to two halves 102 and 103 . All the conducting elements 100 , 101 , 102 , 103 are attached, or glued, to the material 44 , which extends radially to, or beyond, the outermost radius of the conducting rings 102 , 103 . The conducting plates 100 , 101 are connected to the electrical generator (not shown) via electrical connections 110 , 120 respectively.
FIG. 11 shows both a bottom view and a cross sectional view YY of a split version of three component, two ring dispersive pad, also based on the principles of category (1) according to this invention. In the split pad version shown, the central conducting plate is split here into two halves 100 and 101 . The first conducting ring is split into two halves 102 and 103 , and the second conducting ring is split into two halves 104 , 106 . All the conducting elements 100 , 101 , 102 , 103 , 104 , 106 are attached to the conductive dielectric material 44 , which extends radially to, or possibly beyond the outermost radius of the conducting rings 104 , 106 . The conducting plates 100 , 101 are connected to the electrical generator (not shown) via two electrical connections 110 , 120 respectively. As in previous figures, for simplicity purposes, the backing material 78 is omitted. This backing material 78 would have been on top of the conducting plates, away from the pad side which would be in contact with the subject.
FIG. 12 shows both a bottom view and a cross sectional view YY of a single (non-split) version of three component (one central plate, two rings) dispersive pad shown in FIG. 11 . In the single pad version shown, the central conducting plate is 90 , the first conducting ring is 92 , and the second conducting ring 96 . All the conducting elements 90 , 92 , 96 are attached to the gel-like material 44 , which can extend to, or beyond, the outermost radius of the conducting rings 96 . The conducting plate 90 is connected to the electrical generator (not shown) via electrical connection 6 . As in previous figures, for simplicity the electrically non-conductive backing material 78 is omitted. This electrically non-conductive backing material 78 would have been on top of the conducting plates, away from the pad side which would be in contact with the subject.
While the invention has been described so far with reference to a number of specific embodiments, it will be appreciated that the description is illustrative of the invention and is not constructed as limiting of the invention. Various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims. For example, the pads can take the shape of various geometries beyond those described in the figures; likewise, the edges of the conducting material can take the form of curved lines or waves, both on the inside and outside, segmented electrode and segmented conductive dielectric gel, or solid, with different electrical and thermal properties at each component or section; appropriate use of distributed circuit elements like conductive/dielectric layers (conductive gel or other conducting material including metallic foils); lumped (discrete) circuit elements placed on the subject side or the opposite side of the dispersive pad. Other variations are single and split-pads; circular and non-circular; symmetric and non-symmetric; disposable and non-disposable, or by combinations of these approaches. Furthermore, the distributed or lumped-element approach can be used effectively in accordance with category (1), category (2) and category (3) according to the principles of this invention.
As indicated above, the dispersive electrodes can take the shape of various geometries beyond those described thus far, including circular and non-circular; symmetric and non-symmetric. FIGS. 13 and 14 illustrate two illustrative examples of non-circular embodiments. FIG. 13 shows a top view of a rectangular, two-component (one center plate, one rectangular ring) split pad according to the principles of category (1) of this invention (i.e., a resistive-capacitive divider). Many other variations are possible, including multi-component, multi-ring electrodes, as well as single (non-split) pads. Referring now to FIG. 13 , the two central conducting elements 105 , 107 are electrically connected to the external electrical source with two electrical conductors 110 , 120 . The two halves of rectangular conducting rings 109 , 111 , as well as the elements 105 , 107 are mounted on material 44 which can extend to, or beyond, the outermost edges of the conducting elements 109 , 111 . The corners of all elements may be rounded, as shown in this figure, rectangular or any other shape. For simplicity, the backing material 78 is not visible in this figure.
FIG. 14 is a top view of yet another example of a device similar to that shown in FIG. 13 , with the exception that the shape is elliptical. The two central conducting elliptical elements 105 , 107 are electrically connected to an external electrical source with two electrical conductors 110 , 120 . The two halves of the elliptical conducting rings 109 , 111 , as well as the elements 105 , 107 are mounted on, or glued to, the gel-like material 44 which can extend to, or beyond, the outermost radius of the conducting elements 109 , 111 . Again, for simplicity, the backing material 78 is not visible in FIG. 14 .
FIGS. 15 , 16 , 17 , 18 , 19 illustrate yet other variations in accordance with the principles of this invention. The examples shown are in accordance with category (1) of this invention; however, similar variations equally apply to category (2) and category (3). It will be appreciated that the description is illustrative of the invention and is not constructed as limiting of the invention. Various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims like multi-component, multi-ring electrodes; single (non-split) and split pads; symmetric and non-symmetric; disposable and non-disposable, uniform and non-uniform thickness of gel-like material.
FIG. 15 is cross sectional view of a non-segmented return electrode according to the principles of category (1) of this invention. The conductive dielectric intermediate layer 44 between the conducting element 109 and of the subject tissue 43 , not shown, is applied with a thickness increasing smoothly from the center of the device toward its outer edge, covering the entire area of the conducting element 109 . The conducting element 109 is connected to the return or neutral or ground terminal of the electrical unit. The conducting element 109 may be attached, or glued, to the backing material 78 with a field of glue 121 . The material 44 extend radially to the edge of the conducting element 109 .
Another variation of non-uniform application of the conductive dielectric intermediate layer 44 is illustrated in FIG. 16 , which is cross sectional view of a non-segmented return electrode according to the principles of category (1) of this invention. The intermediate layer 44 between the conducting element 109 and of the subject tissue 43 , not shown, is applied with a thickness increasing in steps toward the outer edge of the device, covering part, or all, area of the conducting element 109 . The field 44 can extend to, or beyond, the outermost radius of the conducting element 109 . The conducting element 109 is connected to the return or neutral or ground terminal of the electrical unit. The conducting element 109 may be attached, or glued, to the backing material 78 with a field of glue 121 .
Yet another variation of non-uniform application of the intermediate layer 44 is illustrated in FIG. 17 , which is cross sectional view of a non-segmented return electrode according to the principles of category (1) of this invention. The intermediate layer 44 between the conducting element 109 and of the subject tissue 43 , not shown, is applied with a uniform thickness up to a certain radius and then increases in one step toward the outer edge of the device, covering part, or all, area of the conducting element 109 . The field 44 can extend to, or beyond, the outermost radius of the conducting element 109 . The conducting element 109 is connected to the return or neutral or ground terminal of the electrical unit. The conducting element 109 may be attached, or glued, to the backing material 78 with a field of glue 121 .
Yet another variation of uniform application of the intermediate layer 44 is illustrated in FIG. 18 , which is cross sectional view of a non-segmented return electrode according to the principles of category (1) of this invention. The intermediate layer 44 between the conducting element 109 and of the subject tissue 43 , not shown, is applied with a uniform thickness covering part, or all, area of the conducting element 109 . The field 44 can extend to, or beyond, the outermost radius of the conducting element 109 . The conducting element 109 is connected to the return or neutral or ground terminal of the electrical unit. The conducting element 109 may be attached, or glued, to the backing material 78 with a field of glue 121 .
FIG. 19 is cross sectional view of yet another possible variation, which shows a single (non-split) three-component (one center plate, two-rings) device, similar to the device shown in FIG. 12 , with the difference being that the conductive dielectric layer 44 attached on both sides of the conducting electrodes 130 , 131 , 132 . The central conducting element 130 , as well as the first conducting ring 131 and the second conducting ring 132 are sandwiched between two layers of the intermediate material 44 . One layer of 44 is attached to the backing material 78 . The second layer of 44 is attached to the subject skin or tissue. The central conducting element 130 is connected to the return or neutral or ground terminal of the electrical unit with an electrical wire 6 .
FIGS. 20 , 21 , 22 , 23 , 24 , 25 , 26 depict illustrative examples in accordance with category (2) of this invention, i.e., a passive resistive-inductive divider. It will be appreciated that the description is illustrative of the invention and is not constructed as limiting of the invention. Various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims like multi-component electrodes; single (non-split) and split pads; symmetric and non-symmetric; disposable and non-disposable, uniform and non-uniform thickness of gel-like material.
A top view of non-split device, with an electrically conducting element 201 in a form of a single spiral, according to the principles of category (2) of this invention is illustrated in FIG. 20 . The intermediate layer 44 between the conducting element 201 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness covering part, or all, area of the spiral conducting element 201 . The field 44 can extend to, or beyond, the outermost radius of the conducting element 201 . The center of the conducting element 201 is connected to the return or neutral or ground terminal of the electrical unit with an electrical wire 6 . The conducting element 201 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 21 depicts a top view of a split pad, with an electrically conducting element 202 in a form of a single spiral and a center conducting element 203 , according to the principles of category (2) of this invention. The intermediate layer 44 between the conducting elements 202 , 203 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness. The field 44 can extend to, or beyond, the outermost radius of the conducting element 202 . The conducting elements 202 , 203 are connected to the electrical unit with electrical wires 120 , 110 . The conducting elements 203 , 202 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 22 shows a top view of a yet another version of a split pad, with two electrically conducting elements 204 , 205 in the form of symmetric split spirals, according to the principles of category (2) of this invention. The intermediate layer 44 between the conducting elements 204 , 205 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness. The field 44 can extend to, or beyond, the outermost radius of the conducting element 204 , 205 . The conducting elements 205 , 204 are connected to the electrical unit with electrical wires 120 , 110 as shown. The conducting elements 204 , 205 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 23 shows a top view of a yet another version of a split pad, with two electrically conducting elements 206 , 207 in the form of nested spirals, according to the principles of category (2) of this invention. The intermediate layer 44 between the conducting elements 206 , 207 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness. The field 44 can extend to, or beyond, the outermost edges of the conducting element 206 , 207 . The conducting elements 206 , 207 are connected to the electrical unit with electrical wires 110 , 120 as shown. The conducting elements 206 , 207 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 24 shows a top view of a yet another version of a split pad, with two electrically conducting elements 208 , 209 according to the principles of category (2) of this invention. Conducting element 209 can be in form of a spiral, as shown in the figure. The intermediate layer 44 between the conducting elements 208 , 209 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness. The field 44 can extend to, or beyond, the outermost radius of the conducting element 209 . The conducting elements 208 , 209 are connected to the electrical unit with electrical wires 110 , 120 as shown. The conducting elements 208 , 209 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 25 shows a top view of a yet another version of a single, non-split pad, with one conducting element 211 according to the principles of category (2) of this invention. Conducting element 211 can be in form of a rectangular spiral, as shown in the figure. The intermediate layer 44 between the conducting element 211 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness. The field 44 can extend to, or beyond, the outermost edge of the conducting element 211 . The conducting element 211 is connected to the electrical unit with electrical wires 6 as shown. The conducting elements 211 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 26 depicts yet another version of a split pad with two conducting elements 212 , 213 according to the principles of category (2) of this invention. The conducting elements 212 , 213 can be in the form of a pair of rectangular spirals, as shown in the figure. As noted previously, the conductive spiral may be in the form of other geometries such as circles, ellipses, polygons, and combinations thereof, both symmetric and non-symmetric. The intermediate layer 44 between the conducting elements 212 , 213 and of the subject tissue 43 , not shown, is applied with either a uniform, or non-uniform, thickness. The field 44 can extend to, or beyond, the outermost edge of the conducting elements 212 , 213 . The conducting elements 212 , 213 are connected to the electrical unit with electrical wires 110 , 120 as shown. The conducting elements 212 , 213 may be attached, or glued, to the backing material 78 , not shown in this figure.
FIG. 27 illustrates an example for implementing a system for active voltage distribution in accordance with category (3) of this invention, i.e., an active voltage distribution. Here, the favorable voltage distribution on the electrode is created by supplying the desired voltages from external sources, as opposed to a self generated voltage distribution by using resistive-capacitive or resistive-inductive lumped or distributed elements as described above. The particular example shown in FIG. 27 , represents a single (non-split), four component (one central plate, three-rings) dispersive pad 43 based on active voltage distribution. External voltage source, schematically represented by a transformer 280 , generates voltages V 1 , V 2 and V 3 , supplied to the conducting components—central conducting plate 269 and concentric rings 271 , 274 and 275 —with electrical wires 270 , 277 , 273 and 276 respectively, with the neutral/ground wire represinted by element 268 .
The invention is further described by way of a specific example shown in FIG. 28 . It shows the calculated current density distribution over a circular return electrode designed based on principles of known prior art 290 , and the calculated current density distribution 291 over a four component, three ring circular return electrode designed based on the principles of active voltage distribution according to the principles of this invention. Note that with the prior art pad, the current distribution is highly non-uniform and tend to cluster in the vicinity of the edges, but the distribution is much more uniform for a pad designed according to the principles of this invention.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention. For example, various modifications and applications may occur to those who are skilled in the art, without departing from the spirit and the scope of the invention, as described by the appended claims like multi-component electrodes; single (non-split) and split pads; symmetric and non-symmetric; disposable and non-disposable, uniform and non-uniform thickness of conductive dielectric material; combinations of categories (1), (2) and (3) described above, as well as various combinations of active and passive approaches for generating voltage distributions.
All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. | Herein is disclosed a biomedical dispersive electrode which can redistribute the current in the subject body, increase subject safety, reduce the chance for burns and other tissue damage as well as discomfort experienced by subject during or after usage. Electrodes based on the principles of this invention can be made smaller than electrodes based on the principles of the prior art. | 0 |
FIELD OF THE INVENTION
The present invention relates to the field of dispersed multicolor electroluminescent (EL) lamps employed as backlights of liquid crystal displays and switch keys in a variety of small mobile equipment, and more particularly to dispersed multicolor EL lamps and EL lamp units employing thereof which not only satisfy practical functions such as visibility but also are aesthetically appealing.
BACKGROUND OF THE INVENTION
A conventional dispersed multicolor EL lamp is described using its sectional view in FIG. 9 . In FIG. 9, the thickness dimension is magnified for illustrative purposes.
In FIG. 9, indium tin oxide, for example, is deposited on a transparent resin film 1 using a deposition method such as vacuum sputtering to form a transparent electrode 2 . Then a phosphor layer 3 is formed by dispersing phosphor particles such as zinc sulfide doped with copper in a resin with high dielectric constant such as cyanic resin or fluororubber resin. A dielectric layer 4 is made of the same synthetic resin system as the phosphor layer 3 in which ferroelectric powder such as barium titanate is dispersed. A back electrode layer 5 is made of silver resin system or carbon resin system paste. An insulative cover resist 6 , followed by external electrodes 7 A and 7 B are then formed.
When multicolor text or graphics are displayed using the above conventional EL lamp, the text or graphics are directly drawn onto the surface of the transparent insulative film 1 using optically transmissive color paint; or a sheet on which text or graphics are drawn with optically transmissive color paint is attached to the transparent insulative film 1 . Alternatively, the luminescent color of the phosphor layer 3 is partially changed to match the text or graphics.
In the above conventional dispersed multicolor EL lamps, however, only one type of text or graphics can be displayed.
SUMMARY OF THE INVENTION
In the dispersed multicolor EL lamp in accordance with an exemplary embodiment of the present invention, a first transparent electrode layer is formed on a transparent resin film, and then a first luminescent layer at least containing a phosphor layer in which phosphor powder is dispersed is formed. Then, a transparent electrode layer and luminescent layer are formed layer by layer as a set to form N (N is an integer of N≧2) transparent electrode layers and N luminescent layers. One or more layers in the first to Nth luminescent layers are divided into multiple luminescent color regions for the required text or graphics in the same luminescent layer. A back electrode layer is then formed on the Nth luminescent layer.
The above configuration enables the display of multiple text and graphics in multiple luminescent colors using a single dispersed EL lamp.
In the dispersed multicolor EL lamp in accordance with an exemplary embodiment of the present invention, one or more layers in the first to Nth luminescent layers which are divided into multiple luminescent color regions show an almost colorless monocolor in the same luminescent layer when they are not illuminated, but emit multiple luminescent colors when they are illuminated. When the first to Nth luminescent layers are illuminated independently, multiple divided regions are illuminated in multiple luminescent colors without mutually affecting the coloring of each luminescent layer.
Also in the dispersed multicolor EL lamp in accordance with an exemplary embodiment of the present invention, one or more layers in the first to Nth transparent electrode layers or back electrode layer are electrically separated into two or more regions in the same transparent electrode layer or back electrode layer. This makes it possible to illuminate each divided region of the first to Nth luminescent layers in more than one luminescent color.
Also in the dispersed multicolor EL lamp in accordance with an exemplary embodiment of the present invention, each of the first to (N−1)th luminescent layers is formed of two layers. The first layer is a phosphor layer in which phosphor particles are dispersed. The second layer is formed of a light transmissive insulation layer with higher dielectric constant than that of the first layer. This enables even higher luminance to be achieved when any of the first to (N−1)th luminescent layers are illuminated.
In the dispersed multicolor El lamp in accordance with an exemplary embodiment of the present invention, the Nth luminescent layer is practically formed of two layers. The first layer is a phosphor layer in which phosphor particles are dispersed. The second layer is formed of a white insulation layer with higher dielectric constant than that of the first layer. This makes it possible to achieve even higher luminance when the Nth luminescent layer is illuminated.
Furthermore, in the dispersed multicolor EL lamp in accordance with an exemplary embodiment of the present invention, transparent electrode layers at least other than the first transparent electrode layer are formed of light-transmissive conductive paste with sheet resistance of 50 k or less by printing and drying transparent synthetic resin in which conductive indium tin oxide powder is dispersed. This facilitates the manufacture of the transparent electrode layer, such as by screen printing, at low cost.
Still furthermore, in the dispersed multicolor EL lamp in accordance with an exemplary embodiment of the present invention, the light-transmissive conductive paste for transparent electrode layers may be colored. This allows the overall luminescent color of each of the first to Nth luminescent layers to be changed.
In an EL lamp unit in accordance with an exemplary embodiment of the present invention, a microcomputer is employed to control the turning on and off and flashing of the first to Nth luminescent layers of the dispersed multicolor EL lamp separately or in combination. This makes it possible to automatically turn on, turn off, or flash each of the first to Nth luminescent layers independently or in combination in accordance with predetermined conditions.
Furthermore, in the EL lamp unit in accordance with an exemplary embodiment of the present invention, the microcomputer controls each of the electrically separated electrodes in the first to Nth transparent electrode layers and back electrode layer to automatically apply, shut, or intermittently apply voltage to each of the electrode layers electrically separated into multiple regions independently or in combination. This makes it possible to automatically turn on, turn off, or flash each of divided regions in the first to Nth luminescent layers corresponding to electrically separated electrode layers in the first to Nth transparent electrode layers and back electrode layer independently or in combination, in accordance with predetermined conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a dispersed multicolor EL lamp, displaying text, in accordance with a first exemplary embodiment of the present invention.
FIG. 2 is a sectional view taken along a line 2 — 2 in FIG. 1 .
FIG. 3 is a sectional view taken along a line 3 — 3 in FIG. 1 .
FIG. 4 is a front view of the dispersed multicolor EL lamp, displaying another text different from that in FIG. 1, in accordance with the first exemplary embodiment of the present invention.
FIG. 5 is a plan view of a second transparent electrode layer of a dispersed multicolor EL lamp in accordance with a second exemplary embodiment of the present invention.
FIG. 6 is a plan view of a back electrode layer of the dispersed multicolor EL lamp in accordance with the second exemplary embodiment of the present invention.
FIG. 7 is a sectional view of the dispersed multicolor EL lamp in accordance with the second exemplary embodiment of the present invention.
FIG. 8A is a plan view of a first luminescent layer of dispersed multicolor EL lamp in accordance with a third exemplary embodiment of the present invention.
FIG. 8B is a plan view of a second luminescent layer of dispersed multicolor EL lamp in accordance with the third exemplary embodiment of the present invention.
FIG. 9 is a sectional view of a dispersed multicolor EL lamp of the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Exemplary Embodiment
A first exemplary embodiment of the present invention is described with reference to FIGS. 1 to 4 . Components having the same configuration as those of the prior art are given the same numbers, and thus their detailed explanation is omitted here.
FIG. 1 shows a plan view of a dispersed multicolor electroluminescent lamp (hereafter referred to as an EL lamp) in accordance with the first exemplary embodiment of the present invention. FIG. 2 shows a sectional view taken along a line 2 — 2 in FIG. 1 . FIG. 3 shows a sectional view taken along a line 3 — 3 in FIG. 1 . FIG. 4 shows a front view of the dispersed multicolor EL lamp displaying another text different from that in FIG. 1. A light-emitter of an EL lamp 8 of the present invention consists of the lamination of a first light-emitter 9 and second light-emitter 12 . Looking at the plan view in FIG. 1, the first light-emitter 9 includes a text light-emitter 10 for “PLAY” and background light-emitter 11 . The second light-emitter 12 includes a text light-emitter 13 for “STOP” and background light-emitter 14 . Looking at its sectional view in FIG. 2, the first light-emitter 9 includes a first luminescent layer and first transparent electrode layer 18 . The first luminescent layer includes a first phosphor layer 19 and first dielectric layer 20 . A part of the first phosphor layer 19 corresponding to the text light-emitter 10 is 19 A, and a part of the first phosphor layer 19 corresponding to the background light-emitter 11 is 19 B. The second light-emitter 12 includes a second luminescent layer, a second transparent electrode layer 21 , and a back electrode layer 24 . The second luminescent layer includes the second phosphor layer 22 and second dielectric layer 23 . A part of the second phosphor layer 22 corresponding to the text light-emitter 13 is 22 A, and a part of the second phosphor layer 22 corresponding to the background light-emitter 14 is 22 B. Each of the above layers is protected by an insulation layer 25 . The second transparent electrode layer 21 , first transparent electrode layer 18 , and back electrode layer 24 are respectively connected to the external electrodes 15 , 16 , and 17 .
In FIGS. 2 and 3, the part 19 A of the first phosphor layer 19 corresponding to the text light-emitter 10 and the part 19 B corresponding to the background light-emitter 11 consist of a phosphor with different luminescent color. The part 22 A of the second phosphor layer 22 corresponding to the text light-emitter 13 and the part 22 B corresponding to the background light-emitter 14 also consist of a phosphor with different luminescent color. When an AC electric field is applied between the external electrodes 15 and 16 to illuminate the first luminescent layer, the text light-emitter 10 for “PLAY” and its background light-emitter 11 in FIG. 1 are displayed in different luminescent colors. When an AC electric field is applied between external electrodes 15 and 17 to illuminate the second luminescent layer, the text light-emitter 13 for “STOP” and its background light-emitter 14 in FIG. 4 are displayed in different luminescent colors.
In this exemplary embodiment, each of the transparent electrode layers 18 and 21 , and back electrode layer 24 are uniformly formed on the entire EL light-emitting regions , and each phosphor layer is divided into multiple luminescent color regions in the same phosphor layer.
In the above configuration, a transparent conductive film pre-deposited on a polyester film by sputtering or electron beam evaporation is employed as the first transparent electrode layer 18 . For the second transparent electrode layer 21 , a light transmissive sheet which is a conductive paste with sheet resistance of 50 kΩ or below made by dispersing indium tin oxide dendrite powder in polyester resin, epoxy resin, acrylic resin, phenoxy resin, fluororubber resin, or the like is employed. For the first phosphor layer 19 and second phosphor layer 22 , paste is made by dispersing EL phosphor powder with different luminescent colors for the text and background in resin with high dielectric constant such as cyano ethyl cellulose resin, cyano ethyl pullulan resin, or fluororubber resin containing fluorovinylidine. For the first dielectric layer 20 , milky-white optically transmissive paste is made by dispersing a small amount of ferroelectric powder, typically of barium titanate, in the same resin system as the phosphor layer paste. For the second dielectric layer 23 , paste which reflects white light is made by dispersing ferroelectric powder, typically of barium titanate, in the same resin system as the phosphor layer paste. For the back electrode layer 24 and external electrodes 15 , 16 , and 17 , silver resin paste or carbon resin paste which is normally used for membrane switches is employed. For the insulation layer 25 , electrically insulating paste typically of a polyester system, urethane system, or epoxy system is employed. The above pastes for each layer are printed into a predetermined pattern, typically by screen printing, and then dried to form each layer.
The first transparent electrode layer 18 may also be formed by screen printing the same material as the second transparent electrode layer 21 .
As described above, in the first exemplary embodiment, the first luminescent layer is formed of the first phosphor layer 19 and first dielectric layers 20 and the second luminescent layer are formed of the second phosphor layer 22 and second dielectric layer 23 . By configuring the dielectric layers 20 and 23 with materials having a higher dielectric constant than that of the phosphor layers 19 and 22 , voltage can be more effectively applied to the phosphor than if configuring the luminescent layer only with the phosphor layer, thus achieving higher luminance light emissions.
The first and second phosphor layers may also be colored by adding phosphor dye or phosphor pigment to both pastes. This makes it possible to achieve luminescent color that is different from the natural color of the phosphor.
For the second phosphor layer, phosphor dye or phosphor pigment may be added to the phosphor layer paste for coloring, as well as EL phosphor, when adjusting the luminescent color of the text and background. Addition of phosphor dye or phosphor pigment is not apparent from the light-emitting side when the EL lamp is not turned on. At the same time, there is less color interference when the first phosphor layer is lighted.
In the first exemplary embodiment, the luminescent layer is made of two layers, i.e., the first and second luminescent layers. It is naturally possible to laminate three or more layers. In general, N layers (N is a positive integer) of the luminescent layer may be laminated by providing a transparent electrodes in-between.
In the first exemplary embodiment, each phosphor layer is divided into two luminescent color regions in the same phosphor layer. It may also be divided into three or more, in general to M (M is an integer of N≧2) luminescent color regions.
In the first exemplary embodiment, the external electrodes 15 , 16 and 17 are disposed on opposite ends of the EL light-emitting region. It is apparent that each external electrode may also be disposed on any end independently or all together.
As described above, the dispersed EL lamp in the first exemplary embodiment enables the display of multiple indications by emitting multiple colors from the same light-emitting face.
Second Exemplary Embodiment
Points that differ in a dispersed multicolor electroluminescent (EL) lamp in accordance with the second exemplary embodiment of the present invention from the first exemplary embodiment are as follows. The second transparent electrode layer and back electrode layer are divided into two regions, and an external electrode is provided for each divided region.
FIG. 5 shows a plan view of the second transparent electrode layer of the dispersed multicolor EL lamp in the second exemplary embodiment. FIG. 6 is a plan view of the back electrode layer. FIGS. 5 and 6 show that the second transparent electrode layer and the back electrode layer in the first exemplary embodiment are divided into two regions. FIG. 7 shows a sectional view of the dispersed multicolor EL lamp in the second exemplary embodiment, which corresponds to FIG. 2 illustrating the first exemplary embodiment.
In FIG. 5, a text electrode 26 A is a region of a second transparent electrode layer 26 formed at a position corresponding to the text light-emitter 10 for “PLAY” in FIG. 1. A background electrode 26 B is a region of the second transparent electrode layer 26 corresponding to the background light-emitter 11 . An external electrode 27 A is an electrode for the text electrode 26 A, and an external electrode 27 B is an electrode for the background electrode 26 B. In FIG. 6, a text electrode 28 A is a region of a back electrode layer 28 which is formed in a position corresponding to the text light-emitter 13 for “STOP” in FIG. 4. A background electrode 28 B is a region of the back electrode layer 28 corresponding to the background light-emitter 14 . An external electrode 29 A is an electrode for the text electrode 28 A, and an external electrode 29 B is an electrode for the background electrode 28 B. The first transparent electrode layer is uniformly formed on the entire face.
The materials used for each layer of the EL lamp in the second exemplary embodiment is the same as that used in the first exemplary embodiment.
In the second exemplary embodiment, as described below, different indications may be displayed by changing the combination of selected transparent electrode layers and the back electrode layer when applying voltage to each transparent electrode layer and back electrode layer through each external electrode.
First, when voltage is applied between the first transparent electrode layer 18 and the text electrode 26 A of the second transparent electrode layer 26 , i.e. voltage is applied between the external electrode 16 and external electrode 27 A, the lamp may be controlled to illuminate only the text light-emitter 10 for “PLAY” without illuminating the background light-emitter 11 . In the same way, when voltage is applied between the first transparent electrode layer 18 and the background electrode 26 B of the second transparent electrode layer 26 , i.e. voltage is applied between the external electrode 16 and external electrode 27 B, the lamp may be controlled to illuminate only the background light-emitter 11 for “PLAY” without lighting the text light-emitter 10 . When the external electrode 27 A and external electrode 27 B of the second transparent electrode layer 26 are short circuited, and voltage is applied between the short circuited part and external electrode 16 , the text light-emitter 10 for “PLAY” and its background light-emitter 11 are both illuminated simultaneously in different luminescent colors.
In the same way, when the external electrode 27 A and external electrode 27 B of the second transparent electrode layer 26 are short circuited, and voltage is applied between the short circuited part and the external electrode 29 A for the text electrode 28 A of the back electrode layer 28 , only the text light-emitter 13 for “STOP” is lighted. When the external electrode 27 A and external electrode 27 B of the second transparent electrode layer 26 are short circuited and voltage is applied between the short circuited part and the external electrode 29 B for the background electrode 28 B of the back electrode layer 28 , only the background light-emitter 14 for “STOP” is lighted. When voltage is applied between a short circuited part of the external electrode 27 A and external electrode 27 B for the second transparent electrode layer 26 and a short circuited part of the external electrode 29 A and external electrode 29 B for the back electrode layer 28 , the text light-emitter 13 for “STOP” and its background light-emitter 14 are both illuminated simultaneously in different luminescent colors.
As described above, in the second exemplary embodiment, a range of indications which are also aesthetically appealing may be displayed by selecting the transparent electrode layer and back electrode layer to apply voltage to change the display color and background color as well as the display pattern.
For easier understanding, in the second exemplary embodiment, each of the boundary between different luminescent color regions in the first phosphor layer is patterned such that it approximately coincides with the boundary between electrically separated regions in the second transparent electrode layer. Also the boundary between different luminescent color regions in the second phosphor layer approximately coincides with the boundary between electrically separated regions in the back electrode layer. However, the present invention is not limited to this configuration. A boundary between different luminescent color regions in the phosphor layer and a boundary between electrically separated regions in the transparent electrode layer or back electrode layer may be varied to achieve a wider range of indications.
In this exemplary embodiment, EL lamp includes two luminescent layers: the first and second luminescent layers. Three or more luminescent layers may be laminated by providing a transparent electrode in-between, each luminescent layer may be divided into multiple different luminescent color regions, and each transparent electrode layer may be electrically separated into two or more regions.
Third Exemplary Embodiment
FIG. 8A and 8B show top views of flying image patterns of butterflies 34 and 36 in the first luminescent layer 32 and the second luminescent layer 33 respectively in a dispersed multicolor electroluminescent (EL) lamp in a third exemplary embodiment of the present invention. Each luminescent layer is composed of a phosphor layer and a dielectric layer, as described in the previous exemplary embodiments.
In this EL lamp, an orange EL phosphor is used for the butterflies 34 and 36 , and green EL phosphor is used for backgrounds 35 and 37 to form the first luminescent layer 32 and second luminescent layer 33 respectively.
Each layer is formed using the same materials as in the first exemplary embodiment.
There are two methods for partially changing the luminescent color of the EL lamp: 1) Changing the luminescent color of the EL phosphor contained in the phosphor layer, and 2) additionally dispersing phosphor dye or phosphor pigment, colored to a different color from the luminescent color of the EL phosphor, in the phosphor layer. The light generated in the second phosphor layer must pass through the first phosphor layer before it is finally emitted from the transparent resin film. Therefore, if the luminescent color of the butterfly part and the background in the first phosphor layer are changed using method 2), it is anxious that the color emitted from the second phosphor layer is affected or interfered by the added phosphor dye or phosphor pigment in the first phosphor layer.
Thus, in the third exemplary embodiment, the luminescent color of each EL phosphor for butterflies 34 and 36 and backgrounds 35 and 37 of the first and second luminescent layers 32 and 33 are respectively changed. With this configuration, both first and second luminescent layers 32 and 33 are virtually colorless when they are not illuminated, so the coloring of the first luminescent layer 32 does not affect the second luminescent layer 33 when only the second luminescent layer 33 is lighted. When the first and second luminescent layers 32 and 33 are lighted independently, the butterflies 34 and 36 are illuminated in orange, and the backgrounds 35 and 37 are illuminated in green.
If the EL lamp of the present invention is configured as an EL circuit unit, controlled by the microcomputer 44 (as shown in FIG. 7 ), to illuminate the first and second luminescent layers 32 and 33 alternately, the butterfly may be made to appear as if it is flying by alternately turning on the first and second luminescent layers 32 and 33 .
It is apparent that the EL lamps described in the first and second exemplary embodiments may also be configured to be controlled by a microcomputer to automatically change, turn on, turn off, or flash the displayed indication by selecting the transparent electrode layer or back electrode layer to which voltage is to be applied.
As described above, the present invention offers a dispersed EL lamp which enables multiple colors to be emitted from the same light-emitting face of a single EL lamp. Furthermore, multiple text or graphics may be displayed independently or simultaneously.
Reference Numerals
1 transparent resin film
2 transparent electrode
3 phosphor layer
4 dielectric layer
5 back electrode layer
6 cover resist
7 A, 7 B external electrode
8 EL lamp
9 first light-emitter
10 , 13 text light-emitter
11 , 14 background light-emitter
15 , 16 , 17 , 27 A, 27 B, 29 A, 29 B external electrode
18 first transparent electrode layer
19 , 32 first phosphor layer
19 A, 22 A part corresponding to text light-emitters 10 and 13
19 B, 22 B part corresponding to background light-emitters 11 and
20 first dielectric layer
21 , 26 second transparent electrode layer
22 , 33 second phosphor layer
23 second dielectric layer
24 , 28 back electrode layer
25 insulation layer
26 A, 28 B text electrode
26 B, 28 B background electrode
34 , 36 butterfly
35 , 37 background
Reference Numerals
1 transparent resin film
2 transparent electrode
3 phosphor layer
4 dielectric layer
5 back electrode layer
6 cover resist
7 A, 7 B external electrode
8 EL lamp
9 first light-emitter
10 , 13 text light emitter
11 , 14 background light-emitter
15 , 16 , 17 , 27 A, 27 B, 29 A, 29 B external electrode
18 first transparent electrode layer
19 , 32 first phosphor layer
19 A, 22 A part corresponding to text light-emitters 10 and 13
19 B, 22 B part corresponding to background light-emitters 11 and 14
20 first dielectric layer
21 , 26 second transparent electrode layer
22 , 33 second phosphor layer
23 second dielectric layer
24 , 28 back electrode layer
25 insulation layer
26 A, 28 B text electrode
26 B, 28 B background electrode
34 , 36 butterfly
35 , 37 background | A set of a transparent electrode layer and a luminescent layer in which phosphor particles are dispersed are formed on a transparent resin film, and this set is formed layer by layer to create more than one luminescent layer. One or more luminescent layers are divided into multiple luminescent color regions. Or, the transparent electrode layer is electrically separated into two or more regions. This configuration enables the display of multiple patterns in multiple luminescent colors using one dispersed EL lamp. Accordingly, the multicolor EL lamp, which is aesthetically appealing as well as good visibility, can be provided for a display unit of a range of electronic equipment and backlight for LCDs. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application No. 60/599,510, filed Aug. 6, 2004 and entitled “Suspensions for Wheeled Transport Devices,” which is incorporated by reference herein.
TECHNICAL FIELD
[0002] This invention relates to suspensions for wheeled transport devices such as luggage, carts or containers, configured to be manually pulled in an inclined position behind a pedestrian user.
BACKGROUND
[0003] Wheeled travel luggage and other hand pulled carts such as wheeled garbage cans and garden carts can create discomfort or injury to the user's hand or arm when the wheels inadvertently strike objects in their path or encounter uneven surfaces or sudden changes in elevation that send shock loads to the handle and into the arm, or in some cases flip over causing a twisting of the hand and arm.
[0004] Improvements to such hand-pulled, wheeled devices are desired.
SUMMARY
[0005] According to one aspect of the invention, a wheeled transport device, such as a piece of personal luggage configured to be manually wheeled in an inclined position by a pedestrian user, includes a main body defining a compartment for containing goods to be transported, a handle disposed at an upper end of the body when the transport device is in an operative, inclined position, the handle manually graspable by the pedestrian user while walking, and at least two wheels disposed at a lower end of the body when the transport device is in an operative, inclined position. Each of the two wheels is secured to the body by respective suspensions for independent rotation along a surface upon which the user is walking, and each suspension exhibits a compliance, in response to forces applied to its respective wheel by the surface in a direction opposing wheel motion, selected to sufficiently alter a geometry of the suspension to temporarily change an attitude of its respective wheel with respect to the main body to counter a tendency of the wheeled transport device to rotate about its axis of inclination in response to the applied forces.
[0006] Preferably, the suspension compliance is sufficient to maintain a center of gravity of the wheeled transport device disposed between contact areas between the wheels and the surface, as the suspension deflects and resumes an equilibrium state in response to an impact force imparted to its respective wheel by traversing a sharp step of 5.0 centimeters in height, at a walking speed of about 4.8 kilometers per hour.
[0007] In many cases, the temporarily changed attitude of the respective wheel is its rolling direction. For example, in some cases the suspension is geometrically configured to toe the respective wheel outward in response to the applied forces.
[0008] In some other cases, the temporarily changed attitude of the respective wheel is its camber or its caster.
[0009] In some configurations, each suspension and its respective wheel is detachable as a unit from the main body.
[0010] In some embodiments, each suspension includes a spring to store energy imparted by the applied forces, and a damper to dissipate energy imparted by the applied forces. The damper has an adjustable resistance to suspension deflection in some example, and in some cases the spring is adjustable. In some versions the spring is a leaf spring.
[0011] In some cases, the device is advantageously provided with multiple, interchangeable suspensions of differing properties.
[0012] In some embodiments, the suspension includes an elastomeric travel stop positioned to limit suspension deflection.
[0013] Some examples also include a wheel-driven electric generator that generates electrical power while the device is wheeled along the surface.
[0014] In some cases, the wheels themselves provide the suspension resilience, and the device may be provided with multiple, interchangeable wheels of differing properties.
[0015] In many versions, the handle is collapsible for storage, such as by telescoping motion. In some particularly advantageous embodiments, the wheels are interconnected to the collapsible handle, such that the wheels are automatically retracted when the handle is collapsed.
[0016] Various aspects of the invention feature a hand-pulled/pushed transport device, such as a suitcase, trash can, garden cart, hand cart or any other device, that is supported by at least two wheels connected to the transport device by a linkage system that allows wheel movement in response to impact loads to the wheels. The linkage system preferably has a pivoting attachment to the body of the transport device and the loads imparted to the wheel and linkage are transmitted to the body of the transport device by a spring and damper combination that dissipates at least some of the imparted energy. When a wheel of the transport device encounters an obstacle, the force of the impact is preferably absorbed and dissipated by a spring/damper system, such that less kinetic energy is transferred to the main body of the transport device, reducing the tendency to deviate from the travel path or turn about the long (i.e., inclined) axis of the device. To the extent that the energy of impact causes compression of the spring, the linkage preferably controls wheel movement in a deliberate way so that the wheel moves along a path that increases negative camber and increases toe-out which action causes the wheel to move the transport device in the direction that encourages the center of gravity of the device to stay within the wheelbase of the device, thus reducing the tendency toward overturning.
[0017] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0018] FIG. 1A is a side views of a wheeled transport device as pulled by a person.
[0019] FIGS. 1B and 1C are top and rear views, respectively, showing movement of the near wheel of FIG. 1A in response to hitting a bump.
[0020] FIG. 1D illustrates retracting luggage wheels by collapsing an extendable luggage handle.
[0021] FIG. 2 is an exploded view of a first wheel suspension configuration.
[0022] FIG. 3 is a perspactive view of a second wheel suspension configuration.
[0023] FIG. 4 is an exploded view of a third wheel suspension configuration, with means for retracting the wheel.
[0024] FIG. 4A illustrates a wheel-driven generator.
[0025] FIG. 5 is an exploded view of a fourth wheel suspension configuration, with means for retracting the wheel.
[0026] FIG. 6 is an exploded view of a fifth wheel suspension configuration, with means for retracting the wheel.
[0027] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0028] Referring to FIG. 1A , many two-wheeled, human-powered, pull/push carts, luggage or the like can be rendered unsteady, uncomfortable or overturned by impacts to the wheels caused by rough surfaces, obstructions and/or sudden changes in elevation, such as stairs and curbs, particularly when the impact is to one wheel only, causing an upward motion on that corner and a torque around the pulling axis of the device, which can cause overturning. In the two-wheeled luggage 8 shown, as one wheel 10 hits a bump, the spring and damper 12 of the suspension connecting that wheel to the main luggage body 9 absorb some of the impact load imparted to the device by the bump. Furthermore, referring also to FIG. 1B , when the spring 12 is compressed and the single-pivot axle moves rearward, rotating about axle pivot 11 along the plane of inclination, perpendicular to line 14 , the suspension is configured to move the wheel to toe the wheel outward, increasing the wheel's toe-out angle 18 . The plane of inclination is defined as the plane passing through the wheel/ground contact patch and the handle, in side view, forming an inclination angle 16 with respect to the ground plane of about 45 degrees plus or minus 15 degrees, depending upon luggage dimensions and handle height during rolling. As depicted in FIG. 1C , the wheel is controlled to provide negative camber angle 20 as viewed from the rear. This change in wheel attitude helps to prevent overturning of the device by redirecting the wheels under the center of gravity. The change of wheel attitude occurs on both sides of the device, as the uplift created by the force of the bump on one wheel transfers weight to the opposite wheel, compressing that spring as well. As the device rolls about the longitudinal pulling axis, the negative camber of the wheel that remains in contact with the ground has the positive effect of keeping the wheel more perpendicular to the ground surface 22 , while the toe-out moves the whole device away from the point of upward deflection and in the surface direction corresponding to the angular direction of the torque couple, thereby keeping the center of gravity between the wheels, whereas if it moves outside either wheel the device will overturn. The illustrated embodiment depicts the plane of the axle movement as parallel to the bottom side of the luggage, which makes for an advantageously compact configuration, helping to minimize reductions in cargo space to accommodate suspension components and movement.
[0029] FIG. 1D shows the preparation of a piece of luggage for storage, where collapsing the handle 21 of the luggage retracts the wheels 10 inside the outer faces of the luggage, making for a more compact storage configuration that permits more space internal to the luggage.
[0030] FIG. 2 shows one of many possible solutions to supporting a range of loads imposed on the luggage or other transport device, by interchangeable spring/damper units. The axle 24 that carries the wheel is mounted on the luggage body to pivot about a pivot axis 26 . Axle 24 has mounting bosses 28 to which one of multiple interchangeable spring/damper units, including a light spring/damper 32 and a heavy spring/damper 34 , can be selectively mounted for rotation about an axis perpendicular to axis 26 , but that also allow for some movement about other axes so as to allow the misalignment caused by motion through an arc as dictated by the overall geometry. The body of the luggage or other transport device provides a similarly misalignment-tolerant pivot 30 at which an opposite end of the spring/damper is mounted. Thus, springs/damper units may be originally selected, replaced or interchanged to configure the luggage for a particular loading and/or intended use.
[0031] FIG. 3 shows another of many possible solutions to supporting a range of loads imposed on the luggage or other transport device, by interchangeable spring/damper units. In this case, the axle 36 that carries the wheel 10 pivots on a sub-frame 44 secured to the luggage body 9 . Sub-frame 44 is modular and may be fitted to numerous variations of transport devices. The spring/damper 38 includes a bump stop device 40 that provides a resilient overload stop, and is mounted to a carrier 42 that can be selectively positioned in any of several spaced-apart positions along the axle, so as to provide greater or lesser mechanical advantage to the spring of the spring/damper assembly, thus providing tuneability of the system to accommodate a large range of loads.
[0032] FIG. 4 shows a suspension system configured to provide a spring damper system for a piece of luggage as previously described, but that also retracts the entire wheel system when the handle of the luggage is collapsed to the stored position as shown in FIG. 1D . As in the above embodiments, the luggage or other transport device with a collapsing handle is supported by two wheels 10 rotating on an axle 46 and has the wheels connected to the main body of the luggage by a pivoting knuckle 48 that allows wheel axle pivoting about a linear pivot axis 50 in response to impact loads to the wheels. Loads imparted to the wheel and knuckle are transmitted to the body of the transport device by a spring 60 and damper 62 combination that dissipates at least some of the imparted energy. When wheel 10 encounters an obstacle, force of the impact is absorbed and dissipated by the spring/damper system and less energy is imparted to the main body of the transport device, reducing the tendency to deviate from the travel path or turn on the long axis of the device. To the extent that the energy of impact causes compression of the spring, the linkage controls wheel movement in a way predetermined to cause the wheel to move along a path that increases negative camber and increases toe-out, causing the wheel to move the transport device in the direction that encourages the center of gravity of the device to stay within the wheelbase of the device. The spring/damper combination is contained by a seat 56 and a spindle 58 that pivots on the knuckle, extends through holes 62 defined in mounting block 68 , and is threaded into an adjusting wheel, allowing for adjustment of spring assembly preload. Mounting block 68 travels is free to travel along a track 72 defined in the main luggage body, and is pinned to locating arm 66 at hole 70 . Arm 66 is attached to an extendable telescoping arm 84 of the pulling handle assembly of the transport device. When this arm 84 is pushed inward to its storage position, the bottom of the arm pushes down on the platform end 80 of the locating arm, disengaging the detent pin 76 from its locked position 74 along pin track 75 and enabling the locating arm to slide rearward, permitting the carriage 68 to also move rearward, followed by the entire spring/damper assembly and axle 46 , such that the wheel 10 is retracted into a cavity of the transport device body.
[0033] Referring to FIG. 4A , electrical generator 86 is mounted in the body of the pivoting knuckle 88 and is driven by a spur gear 89 that engages gear teeth 90 internal to road wheel 10 a . It is also possible to mount the generator within the body of the luggage or transport device and drive it by a rotating axle internal to the linkage.
[0034] FIG. 5 shows an alternative suspension system for a piece of wheeled luggage employing a leaf spring rather than a coil spring and providing the ability to tune the system for varying loads, as well as providing retraction of the entire wheel system when the handle of a piece of luggage is collapsed to the stored position. The luggage is supported by two wheels 10 rotating on respective axles 94 connecting the wheels to the transport device by leaf springs 96 that constrain wheel movement along a linear pivot axis by trapping the spring in carrier hub 98 . The leaf spring is located by a detent pin 102 that the user can engage in various holes in the spring to adjust the spring rate. The detent pin is held in engagement by a second leaf spring 100 or other similar mechanism. The entire wheel/hub assembly is positioned by a rigid rod 104 that has a pivoting attachment to the body of the transport device. The location of the wheel inboard or outboard of the body of the luggage is dependent on the angular position of the rigid rod linkage. With rod 104 releasably engaged in a recess 105 in spring clip 106 , the wheel is outboard in the transit position. When the extendable telescoping arm 114 of the pulling handle assembly is pushed down, a cam block 112 disengages spring 106 and pushes the rigid rod 104 through an arc, retracting the wheel assembly. When the extendable telescoping arm is pulled out, a flexible cord 110 pulls up on the crank portion 108 of rod 104 , returning the rod into releasably engagement within recess 105 of spring 106 and pivoting the unloaded wheel assembly again into the outboard transit mode.
[0035] FIG. 6 shows an alternative suspension system for a piece of wheeled luggage, employing an elastomeric wheel 10 b with molded internal ribs that resiliently deform when loaded, both providing effective springing of the load and providing damping of the system. These wheels are preferably interchangeable and each designed to accommodate a different load range. The luggage is supported by two such wheels, each rotating on an axle 118 connected to the transport device by a rigid rod linkage 124 that has a pivoting attachment to the body of the transport device. As with the embodiment of FIG. 5 , the location of the wheel inboard or outboard of the body of the luggage is dependent on the angular position of the rigid rod linkage, and similar means are provided for extending and retracting the wheels. Electrical generator 120 is mounted on a square portion 122 of rigid rod linkage 124 and is driven by a spur gear 125 that engages a rigid gear (not shown) internal to the elastomeric wheel 116 . It is also possible to mount the generator within the body of the luggage or transport device and drive it by a rotating axle internal to the linkage. Further details of wheel-driven generators can be found in a provisional U.S. patent application filed concurrently herewith and entitled “ELECTRICAL POWER GENERATION,” the entire contents of which are incorporated herein by reference.
[0036] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | A wheeled transport device, such as luggage, a trash can, a garden cart or other hand cart configured to be manually wheeled in an inclined position by a pedestrian user, includes a collapsible handle at one end and wheels at the other end. The wheels are independently connected to the device by respective suspensions that exhibit a compliance, in response to forces applied to their respective wheels by the surface in a direction opposing wheel motion, selected to sufficiently alter suspension geometry to temporarily change an attitude, such as toe, camber or caster, of their respective wheels to counter a tendency of the device to overturn in response to the applied forces. | 0 |
TECHNICAL FIELD
The invention relates to a support for the reed of a seam-weaving machine to make a plastic woven fabric continuous by means of a woven seam. To make the woven seam, a seam-weaving shed is formed from seam-warp threads and seam-weft threads are inserted into the seam-weaving shed and shifted against the fell. To shift the seam-weft threads against the fell, the reed has reed dents which are pivotably housed and, starting from the fabric end from which the respective seam-weft thread projects as a warp-thread fringe, press one after the other against the seam-weft thread to be shifted. According to a first mode of operation, the position of the reed dents can be staggered by means of a tilt bar and a pressure bar such that the points at which the reed dents touch the seam-weft thread to be shifted lie approximately on a straight or slightly curved line, the distance of which from the fell constantly changes across the reed.
STATE OF THE ART
Industrial-grade plastic woven fabric for uses where there is an absolutely even surface structure of the fabric, in particular in the case of flat woven plastic paper-forming screens, are made continuous by a woven seam, such as is known from EP-A-0 236 601. To produce a woven seam, warp threads are exposed to a length of e.g. 15 cm at the fabric ends which are to be joined to each other, by removing the weft threads in this area, cf. DE-A103 30 958 (=WO-2005/005718). The so-called woven seam, in which the original weave is exactly reproduced, is then formed from these warp-thread fringes and the weft threads removed from the fabric. To this end, a seam-weaving shed comprising the removed weft threads is stentered, wherein the removed weft threads serve as seam-warp threads. The warp-thread fringes are inserted alternately from the two fabric ends into this seam-weaving shed as seam-weft threads by means of draw-through grippers (cf. EP-A-0 597 494). The warp thread fringes, i.e. the seam-weft threads, and the removed weft threads, i.e. the seam-warp threads, are as a rule monofilaments from 0.1 to 0.5 mm in diameter, and the woven seam is produced after the thermosetting of the fabric, with the result that the threads already have the corrugation or knuckle corresponding to the respective weave. To obtain a woven seam which has a high tensile strength and does not differ from the rest of the fabric in the pattern of the surface which is decisive for the marking in the paper, the seam-warp threads and the knuckles of the seam-weft threads must interweave in the fabric so that a form locking results. The interweaving of the seam-warp threads and seam-weft threads according to their knuckle is achieved inter alia because the reed does not shift the seam-weft threads simultaneously over the whole length, but the seam-weft threads are progressively shifted through the seam-weaving shed, starting from their point of emergence from the fabric end (root position).
A reed which makes possible such a progressive shift of the seam-weft threads is described in DE-U-81 22 448. The reed can be pivoted into an operating position brought close to the fell. The reed dents housed pivotable on a shaft are held back from the fell by a rubber strip. A roll movable across the reed on a guide track presses the reed dents, against the elasticity of the rubber strip, one after the other against the seam-weft thread. Starting from the fabric end at which the seam-weft thread projects as a warp fringe, the roll is moved along the array of reed dents over the whole seam width for each shifting process.
The same object is achieved according to EP-A-0 043 441 by a rotatable needle cylinder which has a plurality of bending needles which are arranged in helical rows of needles. As a further possibility the shifting of seam-weft threads by means of Z-shaped needles, which are arranged in a guide bed alongside each other and individually axially displaceable, is described in this document. The needles engage in the shed with their front Z-end. The Z-shaped needles are pressed one after the other against the fell by means of a slide, with the result that the seam-weft thread is progressively shifted in a wave motion starting from its point of emergence from the fabric end.
A support for the reed of a seam-weaving machine of the type named at the outset is known from EP-A-0 586 959 in which the position of the reed dents can be staggered such that the points at which the reed dents touch the seam-weft thread to be shifted lie on a straight or slightly curved line, the distance of which from the fell increases starting from the point of emergence of the seam-weft thread from the fabric end. The weaving process can thereby be accelerated as, because of the staggering of the reed dents, the movement of the sley is already enough to progressively shift the seam-weft thread out of the fabric starting from its emerging end.
While the process known from DE-U-81 22 448, in which the reed dents are pressed one after the other against the seam-weft thread to be shifted by means of a roll running past them, can also be used with very complex fabrics, the quicker process, known from EP-A-0 586 959, in which the reed dents are arranged staggered on the sley, cannot be used with very complex fabrics, in particular with some structure-tied fabrics. By structure-tied fabrics are meant multi-layered fabrics in which the binding weft is tied into the fabric structure. If when making a woven seam firstly a sley with staggered reed dents is used according to EP-A-0 586 959 and then too many weaving faults and machine stoppages occur during the seam-weaving process, thus it is very troublesome and time-consuming to change to the process in which a sley with a running roll is used according to DE-U-81 22 448. To change over, the whole sley must actually be removed and replaced by a corresponding different sley. In cases of doubt the process with the running roll is therefore used, although there would be a time saving of 20 to 30% with the process with the staggered reed dents.
DESCRIPTION OF THE INVENTION
Technical Object
The object of the invention is to simplify in a seam-weaving process the change from the seam-weaving process using staggered reed dents to the process using a running roll.
Technical Achievement
According to the invention this object is achieved in that, with a support of the type named at the outset, a roll is provided which can be moved on a guide path across the width of the reed in order to pivot the reed dents one after the other to the fell for operation in a second mode of operation and the tilt strip or the pressure strip can be removed from the reed dents for operation in the second mode of operation.
Advantageous Effects
The tilt strip and the pressure strip impact on the reed dents with opposite torque, with the result that together they determine the position of the reed dents. The reed dents are acted on by the torque created by the tilt strip such that their top ends are pressed towards the fell at one end of the reed and away from the fell at the other, while the pressure strip presses the upper ends of the reed dents towards the fell. Expediently both strips are arranged on the rear of the reed dents, the side facing away from the fell, wherein the tilt strip acts on the reed dents underneath the shaft and the pressure strip acts on the reed dents above this shaft. The tilt strip and the pressure strip are both housed at the support such that they can be pivoted in an approximately horizontal plane. Expediently both are rotatably housed in the centre about a vertical shaft and are acted on at the two side ends by adjustment devices, e.g. pneumatic tilt cylinders and, respectively, bearing pressure cylinders. The tilt cylinders can be controlled such that they take up a specific extended position while the bearing pressure cylinders are controlled such that they apply a specific pressing force.
Preferably the bearing pressure cylinders are controlled such that the bearing pressure cylinder on the side of the root position applies approximately 50% more force than the bearing pressure cylinder on the opposite side, wherein it is assumed that the pressure strip is housed at the centre.
As the sley advances the reed dents push the seam-weft thread to be inserted against the fell. Once the seam-weft thread is attached to the fell it presses the reed dents slightly rearward against the force of the pressure strip. In order to permit this rearward pivot movement of the reed dents, the pressure strip is housed such that it can give rearward. To this end, the normally present pivot bearing in the centre of the pressure strip is housed on a sliding block which allows a movement in the direction of the sley movement. Simultaneously the rearward end-position of the reed dents reached by the sliding block when beating up the reed dents is sensed in order to control the progressive rearward movement of the seam-weaving machine along the fabric ends.
The first mode of operation, in which the reed dents are set tilted, has been previously described. The support according to the invention can be modified with few handles such that the seam-weaving machine can also operate in a second mode of operation, in which the seam-weft threads are shifted by means of a running roll, such as is known from DE-U81 22 448 and has been described above. The roll is moved across the width of the reed on a guide track in order to pivot the reed dents one after the other towards the fell. The guide track of the roll is preferably arranged on the front of the support with the result that the roll acts on the reed dents below the shaft. The reed dents are held approximately vertical by a U-shaped bar which extends over the width of the sley. The U-shaped bar is arranged approximately at the level of the shaft with the result that the upper arm of the U-shaped bar abuts the reed dents above the shaft and the lower arm of the U-shaped bar below the shaft. The upper arm of the U-shaped bar is provided with a microcellular rubber strip and the reed dents are pivoted forwards one after the other by the roll and pressed into the microcellular rubber strip in the process. Depending on the arrangement of the tilt strip and the pressure strip, these interfere when operating in the first mode of operation and must be removed or at least pulled back from the reed dents.
For the change from the first mode of operation into the second mode of operation, the tilt strip and/or the pressure strip, if they interfere, are removed from the reed dents or dismantled, the bearing pressure and tilt cylinders or the other adjustment devices are connected without pressure or drive and the U-shaped bar is attached.
For the change from second mode of operation into the first mode of operation, the U-shaped bar is removed and the roll is moved into a parking position on the edge of the support. Also, the tilt strip and the pressure strip are brought into their operating position and the tilt and bearing pressure cylinders or the other adjustment devices subjected to pressure.
Preferably the support is structured such that the tilt strip and the pressure strip act on the reed dents on the rear, the tilt strip below the shaft and the pressure strip above the shaft, and the roll acts on the reed dents on the front below the shaft and the U-shaped bar abuts the front of the reed dents, wherein the arm of the U-shaped bar abutting the shaft has a microcellular rubber strip. For the change from the first mode of operation into the second mode of operation, the tilt strip then merely needs to be removed and the U-shaped bar screwed on. For the change from second mode of operation into first mode of operation, the U-shaped bar is unscrewed, the roll moved into a lateral parking position and the tilt strip fitted. The pressure strip is present in both modes of operation in this version of the invention as already mentioned, in the first mode of operation its task is to press the reed dents against the seam-weft thread to be shifted and thus this against the fell, and it also has the task of controlling the progressive rearward movement of the seam-weaving machine. In the second mode of operation it has no role and is thus moved back until it no longer abuts the reed dents.
The sley customarily consists of an arm hinged to the bottom end on which a crossarm or sley head is arranged which in turn carries the reed. The sley head is preferably attached to the upper end of the arm by means of a joint, wherein the joint shaft runs parallel to the pivot shaft of the sley.
In the first mode of operation this joint is blocked, with the result that the sley head is rigidly connected to the arm of the sley.
In the second mode of operation, on the other hand, the sley head can be pivoted. By means of adjustment devices, e.g. pneumatic cylinders, the sley head is pressed with an adjustable force against a stop with the result that the reed is in its basic position. In the basic position the reed is aligned approximately parallel to the arm of the sley. In the second mode of operation the angle piece is sensed or scanned in order that the sley head, when beating up the seam-weft thread, pivots rearward, and corresponding to this angle piece the progressive rearward movement of the seam-weaving machine along the fabric ends is controlled according to the advance of the seam.
The forces applied by the draw-through gripper and the bearing pressure cylinders are as small as possible in order to achieve the form locking between the seam-weft thread and the seam-warp threads. A particularly preferred procedure in the first mode of operation is that the stress which the draw-through gripper exerts on the seam-weft thread to be shifted and the force with which the bearing pressure cylinder acts on the pressure bar are not constant during the rolling-in or shifting of the seam-weft thread. These forces are preferably greater at the start, while the seam-weft thread is e.g. being pressed into the first three seam-warp threads, and are then reduced. These increased forces make sense, as the shifting of the seam-weft thread at the so-called root position, i.e. the position from which it emerges from the fabric end as a warp-thread fringe, is particularly difficult and according to experience requires greater forces. If the seam-weft thread is made to engage with say the first three warp threads it makes sense to lower the stress applied by the draw-through gripper in order to prevent the corrugation or knuckle of the seam-weft thread from being partly pulled flat. Generally the tension applied by the draw-through gripper is reduced by approximately half and the force applied by the bearing pressure cylinders is likewise approximately halved. As already mentioned, the bearing pressure cylinder on the root side applies in each case approximately 50% more force on the pressure strip than the bearing pressure cylinder on the other side. Reducing the applied forces requires a short period of time, and the sley therefore preferably remains stationary during this period of time once the seam-weft thread has been made to engage with the first seam-warp threads.
This reduction in force when shifting a seam-weft thread in a seam-weaving machine in which the seam-weft thread is progressively introduced by means of a tilted reed is particularly useful when operating the seam-weaving machine with the support according to the invention. However, this process for operating a seam-weaving machine is also suitable and advantageous for operating a seam-weaving machine which can be operated only in the first mode of operation (EP-0 586 959).
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment example of the invention is explained below with reference to the drawing. There are shown in:
FIG. 1 in a side view, the whole sley including the drive;
FIG. 2 the support of the reed dents in a spatial representation from above and the rear;
FIG. 3 the support of the reed dents in a spatial representation from above and the front;
FIG. 4 the support in a side view, set up for the first mode of operation and
FIG. 5 the support in a side view, set up for the second mode of operation.
WAY(S) OF CARRYING OUT THE INVENTION
In FIG. 1 a sley 10 is shown which is pivoted in customary manner by a linear motor 12 as a sley drive. The sley 10 consists of an arm 14 which can be pivoted at the bottom end in a bearing and at the top end carries a sley head 16 , wherein the drive rod of the linear motor 12 is articulated to the arm 14 just below the sley head 16 . Bearing supports 18 in which a shaft 20 , removable by means of a shaft bar 21 ( FIG. 4 ), is fixed, project upwards at the lateral ends of the sley head 16 . Reed dents 22 which in their totality form the reed are ranged on the shaft 20 . For reasons of clarity, however, only one of the reed dents is represented. In their lower region the reed dents 22 have a bore with which they are strung onto the shaft 20 . Spacing rings lying between keep them at the distance which is predetermined by the thread count of the fabric.
As can be seen from FIG. 2 , on the rear of the sley head 16 which faces the linear motor 12 , a tilt strip 24 which extends over almost the whole width of the sley head 16 is housed pivotable about a vertical axis, wherein the pivot point is located in the middle of the tilt strip 24 . Tilt cylinders 26 which act on the lateral ends of the tilt strip 24 are attached to the two lateral bearing supports 18 ( FIGS. 2 and 4 ). The degree of extension of the tilt cylinders 26 can be set. The tilt strip 24 is arranged below the shaft 20 with the result that it engages with the reed dents 22 below the shaft 20 .
A pressure strip 30 is housed similar to the tilt strip 24 above the tilt strip 24 and above the shaft 20 rotatable about a vertical axis. The pressure strip 30 also extends over the whole width of the sley head 16 . Bearing pressure cylinders 32 which act on the pressure strip 30 at their lateral ends are also attached to the bearing supports 18 . The pressure strip 30 is housed in the middle at a sliding block 34 which can be displaced in a guide in longitudinal direction, i.e. in the direction of the sley movement. The front of the pressure strip 30 which acts on the reed dents 22 is provided with a rubber bearing support 36 .
The seam-weaving machine is operated in a first mode of operation by means of the tilt strip 24 and the pressure strip 30 . By way of explanation it is assumed that first of all a seam-weft thread which projects from the right-hand fabric end as a warp-thread fringe and has been inserted into the seam-weaving shed by means of a draw-through gripper is now to be rolled in and shifted against the fell by means of the sley. The points at which the reed dents 22 beat up the fell lie approximately in the centre of the length of each of the reed dents 22 . These points always lie on a straight or slightly curved line, the so-called beat-up line. When the sley 10 is located at its rear reversal point, the left-hand tilt cylinder 26 is extended and the right-hand tilt cylinder 26 withdrawn. The tilt strip 24 thus rotates in a roughly clockwise direction viewed from above. As the tilt strip 24 engages below the shaft 20 onto which the reed dents 22 are strung, the part of the reed which is located above the shaft 20 , and thus the beat-up line, moves in the opposite direction, and the reed is deformed such that the reed dents 22 on the right-hand side are pivoted slightly forwards and the reed dents on the left-hand side slightly rearward. The outermost right-hand reed dent 22 is thus the first to meet the seam-weft thread and presses it against the fell. At the rear reversal point of the sley 10 the pressure in the right-hand bearing pressure cylinder 32 is increased with the result that the seam-weft thread is pressed into the shed with particularly great force immediately after emerging from the fabric end. The draw-through gripper still applies to the seam-weft thread the relatively high draw-through stress with which it has drawn the seam-weft thread through the seam-weaving shed. Because of the high bearing pressure which is applied by the bearing pressure cylinder 32 to the seam-weft thread, and because of the draw-through stress which is applied by the draw-through gripper, it is ensured that the knuckles of the seam-weft thread grip in form locking manner and precisely with the knuckles of the first, i.e. the outermost right-hand, seam-warp threads. As mentioned at the outset, fabric-weft threads are used as seam-warp threads and fabric-warp threads as seam-weft threads, after the thermofixing of the fabric, with the result that the threads have a residual knuckle or corrugation. In order that the woven seam in the woven pattern does not differ from the fabric, the seam-warp threads and the seam-weft threads must interlock with their knuckles again corresponding to the weave. The creation of this engagement between seam-weft thread and seam-warp threads is particularly critical in the first three seam-warp threads. In order to bring the seam-weft thread into engagement with the first three seam-warp threads, the pressure in the bearing pressure cylinders 32 is approximately doubled. When the engagement with the first three seam-warp threads is created, the pressure is reduced to the normal value, thus approximately halved. The sley 10 remains stationary during the period of time necessary for the pressure reduction. This period of time is e.g. approximately 50 ms. Simultaneously the stress applied by the draw-through gripper is also reduced from the draw-through stress to the hold or roll-in stress.
While the outermost right-hand reed dents 22 press the seam-weft thread into the seam-warp threads, the sley 10 moves on. The chosen pressure in the bearing pressure cylinders 32 is such that the pressure strip 30 is pressed rearward by the reed dents 22 which have reached the fell, i.e. pivoted clockwise in the chosen example. The reed dents 22 act progressively from right to left on the seam-weft thread to be shifted with the result that finally this is completely pressed against the fell and engages with the seam-warp threads. Generally, the next seam-weft thread to be shifted is a warp-thread fringe which projects from the left-hand fabric end. The tilt cylinders 26 and the bearing pressure cylinders 32 are therefore controlled in mirror-image fashion, i.e. the right-hand tilt cylinder 26 is now extended and the pressure in the left-hand bearing pressure cylinder 32 raised to the pressure necessary to press the seam-weft thread into the first left-hand seam-warp threads.
Depending on the horizontal distance of the bearing of the sley 10 from the fell, the sliding block 34 at which the pressure strip 30 is housed is shifted rearward to a greater or lesser degree after the shifting of a seam-weft thread. The rearward end-position reached by the sliding block 34 when beating up the reed dents 22 is sensed by a first sensor 35 . If the displacement of the end-position exceeds a predetermined extent, the seam-weaving machine is moved rearward from the fell by a predetermined step. The progression of the fell is thereby taken into account. As both fabric ends fest are clamped fast, it is the seam-weaving machine which must be moved on according to the progress of the seam.
The seam-weaving process according to this first mode of operation is very quick, but cannot be used with all fabrics. With very complex fabrics, in particular with structure-tied fabrics, it has thus far not been possible to use it. If too many faults occur when making a continuous fabric and therefore the seam-weaving machine too often remains stationary, then it is possible to change the invention over to a second mode of operation with which almost all fabric can be made continuous. This requires a modification of the sley 10 . In FIGS. 1 to 3 both the components necessary for the first mode of operation and those necessary for the second mode of operation are fitted to the sley 10 . FIG. 4 shows, on the other hand, the sley 10 with the components which are necessary for the first mode of operation, and FIG. 5 shows the sley 10 with the components which are necessary for the second mode of operation, wherein in each case the interfering components of the other mode of operation are removed or have been moved out of the operating position.
To modify the sley 10 from the first into the second mode of operation, the reed dents 22 can remain on the shaft 20 , but the tilt strip 24 is removed and a bar 40 with a U-profile is attached in front of the reed dents 22 , added to which the bearing pressure cylinders 32 are connected without pressure, with the result that the pressure strip 30 no longer abuts the rear of the reed dents 22 . As will be explained later in more detail, the fixing of a joint 64 between the sley head 16 and the arm 14 is also released for the second mode of operation. The U-shaped bar 40 is screwed on at approximately the level of the shaft 20 to the shaft bar 21 to which the shaft 20 with the reed dents 22 is attached. The lower arm 42 of the U-profile of the bar 40 abuts the reed dents 22 below the shaft 20 , and the upper arm 44 of the U-profile abuts the reed dents 22 above the shaft 20 . The upper arm 44 carries a microcellular rubber strip, not shown, which is inserted into a groove 46 on the rear of the upper arm 44 .
Below the lower arm 42 on the sley head 16 there is a guide track 50 which extends over the whole width of the sley head 16 and in which a roll 52 is guided. In the second mode of operation the roll 52 acts on the bottom ends of the reed dents 22 below the lower arm 42 , with the result that the upper, substantially longer part of the reed dents 22 is pivoted forwards and in the process is pressed into the microcellular rubber strip on the rear of the upper arm 44 of the bar 40 . When the roll 52 is moved into the guide track 50 over the front side of the sley head 16 , it presses the reed dents 22 forward one after the other. The roll 52 is carried by a sliding block, sliding in the guide track 50 , which is fixed to a toothed belt 54 which is guided over two cogged-belt pulleys 56 which are arranged laterally at the bearing supports 18 . The left-hand cogged-belt pulley 56 is driven by a step motor 58 ( FIG. 3 ). In the first mode of operation the roll 52 is not needed and is therefore moved into a lateral parking position.
To shift the seam-weft threads in the second mode of operation, the sley 10 is pivoted into its front end-position in which the reed dents 22 , the beat-up line of which is aligned parallel to the fell in the second mode of operation, stand immediately in front of the fell or can already touch the seam-weft thread to be shifted. The sley 10 stops briefly in its front end-position, while the roll 52 is pulled along the guide track 50 and in the process briefly pivots out the individual reed dents 22 one after the other, with the result that these can then roll the seam-weft thread into the shed. After the roll 52 has passed, the individual reed dents 22 are pivoted back into their starting situation by the microcellular rubber strip in the groove 46 . The roll 52 thus creates a continuous wave in the reed dents 22 .
A sheet-metal strip 60 which extends over the whole width of the sley head 16 and is attached to the lower arm 42 is arranged before the bottom ends of the reed dents 22 . The roll 52 thereby does not directly act on the bottom ends of the reed dents 22 , but firstly displaces only the sheet-metal strip 60 which transmits this displacement onto the reed dents 22 . The shape of the continuous wave can be influenced by the elasticity of the sheet-metal strip 60 . The more elastic the sheet-metal strip 60 , the steeper the edges of the wave. If a flatter wave is desired, a thicker sheet-metal strip 60 of lower elasticity can be used, or two sheet-metal strips 60 can be inserted.
As is seen in FIG. 1 , the arm 14 of the sley 10 has a joint 62 approximately in the middle of its length. The angle which the sley head 16 and thus the reed dents 22 adopt vis-à-vis the fell can be set by means of this joint 62 .
The sley head 16 is articulated to the top end of the arm 14 by means of the joint 64 already mentioned above ( FIG. 3 ). The joint 64 is operative only in the second mode of operation. The sley head 16 can be tilted by two pneumatic pressure cylinders 66 , 68 . The left-hand pressure cylinder 66 is smaller in size and is used in the second mode of operation to control the force with which the reed is pressed against the fell. A second sensor 69 is fitted to the arm 14 of the sley 10 and senses the angle of tilt of the sley head 16 around the joint 64 . The second sensor 69 ascertains the end-position reached under the force of the left-hand pressure cylinder 66 and thereby controls the progressive rearward movement of the seam-weaving machine.
The larger right-hand pressure cylinder 68 serves likewise in the second mode of operation to support the sley head 16 at the rear reversal point of the sley movement in order that this and the reed dents 22 do not strike the harness. When the sley 10 moves rearward the right-hand pressure cylinder 68 is therefore subjected to pressure.
Attached to the bottom of the sley head 16 is an angle piece 70 , the vertical arm of which rests against the front of the arm 14 when the reed is aligned parallel to the arm 14 , and which thereby prevents the sley head 16 from tilting forwards. In the first mode of operation the joint 64 is fixed by solidly connecting the angle piece 70 to the arm 14 by means of a threaded bolt 72 ( FIGS. 3 and 4 ). The pressure cylinders 66 , 68 are thereby without effect in the first mode of operation. For the second mode of operation, on the other hand, the threaded bolt 72 is removed ( FIG. 5 ), with the result that the joint 64 becomes operative.
In a recess of the U-shaped bar 40 a thrust block 74 is arranged which in the first mode of operation serves to bend the shaft 20 , as shown in FIGS. 5 and 6 of EP-0 586 959, in order to match the shape of the reed to the curvature of the fell.
LIST OF REFERENCE NUMBERS
10 sley
12 linear motor
14 arm
16 sley head
18 bearing supports
20 shaft
21 shaft bar
22 reed dents
24 tilt strip
26 tilt cylinder
30 pressure strip
32 bearing pressure cylinder
34 sliding block
35 first sensor
36 rubber bearing support
40 U-shaped bar
42 bottom arm
44 top arm
46 groove
50 guide track
52 roll
54 toothed belt
56 cogged-belt pulley
58 step motor
60 sheet-metal strip
62 joint
64 joint
66 left-hand pressure cylinder
68 right-hand pressure cylinder
69 second sensor
70 angle piece
72 threaded bolt
74 thrust block | The support is provided for a reed of a seam weaving machine used for joining two opposite ends of a synthetic fabric by means of a woven seam. The reed is provided with pivotally mounted reed dents ( 22 ). The support includes a tilt strip ( 24 ) and a pressure strip ( 30 ), as well as devices ( 26, 32 ) for positioning the tilt strip ( 24 ) and the pressure strip ( 30 ) at angles relative to the bearing mechanism. A roll is also provided which can be moved along a track across the width of the reed. A U-shaped bar ( 40 ) can also be placed on the front side of the reed dents ( 22 ). | 3 |
BACKGROUND
This disclosure relates generally to an acoustic source, and more particularly to a suspension element associated with an acoustic source.
SUMMARY
In accordance with an aspect, an apparatus comprises first and second rigid elements and a suspension element which couples the first rigid element to the second rigid element such that the first rigid element is movable in a reciprocating manner relative to the second rigid element. The suspension element comprises a concave surface, a convex surface, and at least first and second radial segments of opposite concavity, the first segment extending away from the concave surface and the second segment extending away from the convex surface.
In some implementations the first and second radial segments are oriented such that lines which bisect the segments lengthwise are tangential to a circle with a radius less than an inner radius of the suspension element.
In some implementations the apparatus further comprises a first radial feature comprising the first and second radial segments of opposite concavity.
In some implementations the apparatus further comprises a second radial feature which extends away from the concave surface.
In some implementations the first and second radial features traverse a semi-circular roll of the suspension element.
In some implementations the first and second radial features are presented in alternation.
In some implementations the second radial segment extends from an apex of the roll to an outer edge of the roll.
In some implementations the second radial segment is characterized by a curved cross-section with a minimum height proximate to the apex of the roll and a maximum height proximate to the outer edge of the roll.
In some implementations the first radial segment extends from an inner edge of the roll to the apex of the roll.
In some implementations the first radial segment is characterized by a curved cross-section with a maximum depth proximate to a midpoint between the apex of the roll and an inner edge of the roll.
In some implementations the second radial feature is characterized by a curved cross-section with a maximum depth proximate to the apex of the roll.
In some implementations the first and second radial features span only a portion of the distance between an inner edge and outer edge of the roll.
In some implementations the suspension element comprises a rolled shape.
In some implementations the rolled shape comprises two or more rolls.
In some implementations the first and second radial features are spaced regularly along the suspension element.
In some implementations the second radial feature has a depth that varies along a length of the second radial feature.
In some implementations the suspension element comprises a surround.
In some implementations the suspension element comprises a spider.
In some implementations a material thickness of the second radial segment varies along a length of the second radial segment.
In some implementations the thickness of the second radial segment is greatest at the portion of the second radial segment proximate to an outer edge of the roll.
In accordance with an aspect, an apparatus comprises a diaphragm, a frame, and a suspension element which couples the diaphragm to the frame such that the diaphragm is movable in a reciprocating manner relative to the frame. The suspension element comprises a roll which defines a concave surface and a convex surface. The roll comprises at least one feature having inner and outer ends proximate to an inner edge of the roll and an outer edge of the roll, respectively, and first and second segments of opposite concavity, the first segment extending away from the concave surface and the second segment extending away from the convex surface.
In some implementations the first feature comprises the first and second segments of opposite concavity.
In some implementations the roll further comprises a second feature which extends away from the concave surface.
In some implementations the first and second features are oriented such that lines which bisect the features lengthwise are tangential to a circle with a radius less than an inner radius of the suspension element.
In some implementations the second segment extends from an apex of the roll to an outer edge of the roll.
In some implementations the second segment is characterized by a curved cross-section with a minimum height proximate to the apex of the roll and a maximum height proximate to the outer edge of the roll.
In some implementations the first segment is characterized by a curved cross-section with a maximum depth proximate to a midpoint between the apex of the roll and an inner edge of the roll, and minimum depths proximate to the apex of the roll and the inner edge of the roll.
In some implementations the second feature is characterized by a curved cross-section with a maximum depth proximate to the apex of the roll, and minimum depths proximate to the inner edge of the roll and the outer edge of the roll.
In some implementations the first and second features are presented in alternation.
In accordance with an aspect, a loudspeaker suspension comprises a loudspeaker suspension structure having an inner circumferential border and an outer circumferential border, and a first feature extending from the inner circumferential border to the outer circumferential border, wherein the first feature comprises a first segment having a first concavity and a second segment having a second concavity, the second concavity being an inverse of the first concavity.
In some implementations the loudspeaker suspension further comprises a second feature extending from the inner circumferential border to the outer circumferential border and having the first concavity.
In some implementations, the first and second features are oriented such that lines which bisect the features lengthwise are tangential to a circle with a radius less than an inner radius of the suspension structure.
In some implementations the first and second features are presented in alternation.
In some implementations the suspension structure comprises a roll.
In some implementations the first feature transitions from the first concavity to the second concavity proximate to an apex of the roll.
In some implementations the first and second features span only a portion of the distance between the inner circumferential border and the outer circumferential border.
In accordance with another aspect an apparatus comprises: means for coupling a first rigid element to a second rigid element such that the first rigid element is movable in a reciprocating manner relative to the second rigid element, the coupling means comprising first and second radially oriented features of opposite concavity.
BRIEF DESCRIPTION OF THE FIGURES
For purposes of illustration some elements are omitted and some dimensions are exaggerated.
FIG. 1 is a perspective view of an acoustic device with a suspension element characterized by radial features with variations of concavity.
FIG. 2 is a top view of the suspension element of FIG. 1 .
FIG. 3 illustrates a groove feature of the suspension element of FIG. 1 .
FIG. 4 is a cross-sectional view of a groove feature of the suspension element of FIG. 2 along section A-A.
FIG. 5 is an expanded view of the groove feature of FIG. 3 including a series of cross-sections.
FIG. 6A illustrates a groove portion of a rib-and-groove feature of the suspension element of FIG. 1 .
FIG. 6B illustrates a rib portion of a rib-and-groove feature of the suspension element of FIG. 1 .
FIG. 6C illustrates a rib-and-groove feature of the suspension element of FIG. 1 .
FIG. 7 is a cross-sectional view of a rib-and-groove feature of the suspension element of FIG. 2 along section B-B.
FIG. 8 is an expanded view of the rib-and-groove feature of FIG. 6C including a series of cross-sections.
FIG. 9 illustrates an exemplary force versus displacement curve for a suspension element of similar dimensions and materials to the suspension element of FIG. 1 , but without the rib-and-groove features.
FIG. 10 illustrates an exemplary force versus displacement curve for the suspension element of FIG. 1 .
FIGS. 11A and 11B illustrate a portion of a rib-and-groove feature of FIG. 1 .
DETAILED DESCRIPTION
FIG. 1 illustrates an acoustic device such as a loudspeaker, driver or transducer. The acoustic device includes a diaphragm 100 (sometimes referred to as a cone, plate, cup or dome) coupled to a frame 102 via a suspension element 104 sometimes referred to as a surround. However, the features described herein could be utilized in a spider or other suspension element. The diaphragm may be circular or non-circular in shape. For example, and without limitation, the diaphragm could be an ellipse, square, rectangle, oblong, or racetrack. The frame may be coupled to an enclosure (not illustrated). The suspension element 104 allows the diaphragm 100 to move in a reciprocating manner relative to the frame 102 and enclosure in response to an excitation signal provided to a motor that outputs a force to diaphragm 100 . Movement of the diaphragm causes changes in air pressure which result in production of sound.
In some examples, as shown in FIGS. 1 and 2 , the suspension element 104 is a circular half roll having an inner edge 306 and an outer edge 308 , separated by a radial width or span. The suspension element 104 can include an inner landing 310 extending radially inward from the inner edge 306 and an outer landing 312 extending radially outward from the outer edge 308 for connection to the diaphragm 100 and frame 102 , respectively. The half roll may have a convex surface 300 facing away from the interior of the enclosure, and a concave surface 302 (shown in FIGS. 3 and 4 ) facing toward the interior of the enclosure. Although the suspension element 104 is shown as a half roll having a single convolution, the suspension element 104 could be, without limitation, a full roll, an inverted half roll (i.e., flipped over 180 degrees), or a roll having multiple convolutions, and could include variations of concavity and other features. A convolution as used herein comprises one cycle of a possibly repeating structure, where the structure typically comprises concatenated sections of arcs. The arcs are generally circular, but can have any curvature. Although the suspension element 104 is shown as circular in shape, the suspension element 104 could also be non-circular in shape. For example, without limitation, the suspension element 104 could be an ellipse, toroid, square, rectangle, oblong, racetrack, or other non-circular shapes. In places where the terms circumferential, radial, or other circle-specific terminology is mentioned, it should be understood that we also mean to encompass non-circular geometries.
The suspension element 104 includes rib and groove features which may enhance axial stiffness, free length, force-deflection relationships, and buckling resistance, and may reduce the overall mass of the suspension element. For example, the suspension element 104 may include one or more radial rib features, groove features, and rib-and-groove features. Examples of these features are described below.
Referring to FIG. 2 , suspension element 104 includes radial groove (or trench) features 304 and radial rib-and-groove features 500 . The groove features 304 and rib-and-groove features 500 generally extend from an inner edge 306 to an outer edge 308 of the roll. In other examples, the groove features 304 and rib-and-groove features 500 need not extend over the entire span from the inner edge 306 to the outer edge 308 .
In some examples, the groove features 304 and rib-and-groove features 500 generally extend at an angle to the radial direction, or more generally, at an angle to the normal of the inner edge 306 of the suspension element 104 , at the point of the groove or rib-and-groove closest to the inner edge 306 . In other words, the groove features 304 may be radially oriented such that line 202 which bisects the groove features 304 lengthwise is tangential to a circle with a radius less than the inner radius (R i ) of the suspension element 104 . Similarly, the rib-and-groove features 500 may be radially oriented such that line 204 which bisects the rib-and-groove features 500 lengthwise is tangential to a circle with a radius less than the inner radius (R i ) of the suspension element 104 .
As shown in FIG. 2 , each groove feature 304 and rib-and-groove feature 500 may be skewed by an angle alpha (a) relative to radius lines R 1 , R 2 which are normal to the inner edge of the suspension element 104 . For example, alpha represents the angle between line 202 and radius line R 1 in FIG. 2 . Alpha can vary over a wide range, and need not be the same for the groove features 304 and the rib-and-groove features 500 . Where the path of the groove feature 304 or rib-and-groove feature 500 traverses a substantially straight line from inner edge to outer edge, the angle alpha is preferably between 30 and 60 degrees (or −30 to −60 degrees), although useful behavior is obtained with an angle between 10 and 80 degrees (or −10 to −80 degrees). Negative angles of alpha refer to groove features 304 or rib-and-groove feature 500 that incline in the opposite direction from the radial (or normal) to that shown in FIG. 2 . Groove features 304 and rib-and-groove features 500 can be straight or curved. The radius of curvature along the length of the groove or rib-and-groove can be infinite (i.e. a straight line), a finite constant, or smoothly or otherwise varying. For examples with constant, smoothly or otherwise varying curvature, alpha can vary between 0 and 90 degrees.
Referring to FIGS. 3 and 4 , the groove features 304 are further described. Groove features 304 extend outward from the concave surface 302 of the roll toward the interior of the enclosure. Groove features 304 may traverse the roll from approximately an inner edge 306 to an outer edge 308 of the roll. In other words, inner end 314 and outer end 316 of the groove feature 304 may be proximate to the inner landing 310 and outer landing 312 of the suspension element 104 , respectively. Alternatively, groove features 304 may traverse the roll from a point offset from the inner edge 306 to a point offset from the outer edge 308 , or onto the inner and/or outer landings 310 , 312 .
FIG. 5 is an expanded view of a groove feature 304 including a series of cross-sections 400 , 402 , 404 , 406 , 408 , 410 , 412 . As shown in the cross-sections, the groove feature 304 may include a curved trough or a generally V-shaped notch 416 with a rounded tip 414 that extends downward from the concave surface 302 of the roll toward the interior of the enclosure. Various geometries are possible for the notch, including without limitation a square-shaped notch with rounded edges. Other geometric aspects of the notch, including the curvature and angle of the notch and the radius of the rounded tip, may be constant or may vary along the length of the groove feature 304 . The depth of the groove feature 304 relative to the roll may vary as the notch traverses from the inner edge 306 to the outer edge 308 of the roll. For example, the depth of the groove feature 304 may range from zero depth at ends 314 , 316 to a maximum depth somewhere between the ends 314 , 316 . In one example, the maximum depth may be located at radius R m (as shown in FIG. 2 ), which is the midpoint between the inner and outer edges 306 , 308 of the roll. In other words, the groove defined by groove feature 304 may be deepest proximate to the apex of the roll. A transition radius may be provided at the boundary between the groove feature 304 and the roll, in lieu of sharp edges. It should be understood that a wide variety of variations could be implemented and symmetry need not be maintained. For example, the point where the groove is deepest may vary. Moreover, in some examples, the groove depth may remain constant over a large portion of the length of the groove. In other examples, the groove depth may have a plurality of local maxima and minima along the groove path, forming undulations in the bottom of the groove, which could help minimize the impact of “pull up” due to stiffening of the suspension element at the extremes of the excursion path.
Referring to FIGS. 6 and 7 , the rib-and-groove features 500 are further described. Rib-and-groove features may include an inner segment 502 and an outer segment 504 . As shown in FIG. 6A , the inner segment 502 may extend outward from the concave surface 302 of the suspension element toward the interior of the enclosure, thereby presenting a groove in the convex surface of the suspension element 104 . The outer segment 504 defines an inflexion of concavity relative to the inner segment 502 . In other words, if the inner segment 502 is concave when facing the interior of the enclosure, the outer segment 504 is convex when facing the interior of the enclosure. As shown in FIG. 6B , the outer segment 504 extends outward from the convex surface 300 of the suspension element toward the exterior of the enclosure, thereby presenting a rib in the convex surface of the suspension element 104 . FIG. 6C shows the inner segment 502 of FIG. 6A (the groove portion) combined with the outer segment 504 of FIG. 6B (the rib portion) which together form a rib-and-groove feature 500 . Although the examples shown in FIGS. 6A-6C show a groove for the inner segment 502 and a rib for the outer segment 504 , other examples may include a rib for the inner segment 502 and a groove for the outer segment 504 .
The rib-and-groove features 500 may traverse the roll from approximately the inner edge 306 to the outer edge 308 of the roll. In other words, inner end 510 and outer end 516 of the rib-and-groove feature 500 may be proximate to the inner landing 310 and outer landing 312 of the suspension element. Alternatively, rib-and-groove features 500 may traverse the roll from a point offset from an inner edge 306 to a point offset from an outer edge 308 , or onto the inner and/or outer landings 310 , 312 . In some examples, inner and outer ends 510 , 512 of the inner segment 502 (the groove portion) may be proximate to the inner edge 306 of the roll and the apex of the roll (R m ), respectively, while inner and outer ends 514 , 516 of the outer segment 504 (the rib portion) may be proximate to the apex of the roll (R m ) and the outer edge 308 of the roll, respectively. However, other locations are contemplated for inner and outer ends 510 , 512 , 514 , 516 . For example, for the inner segment 502 (the groove portion), inner end 510 may be at a point offset from an inner edge 306 of the roll and outer end 512 may be at a point offset from the apex of the roll. Similarly, for the outer segment 504 (the rib portion) outer end 516 may be at a point offset from an outer edge 308 of the roll, and inner end 514 may be at a point offset from the apex of the roll.
In some examples, the rib-and-groove feature 500 transitions from the inner segment 502 (the groove portion) to the outer segment 504 (the rib portion) approximately at the apex (R m ) of the roll. However, this transition could occur at other locations on the roll. Moreover, in some examples, the outer end 512 of the inner segment 502 transitions directly into the inner end 514 of the outer segment 504 . In other words, the groove transitions directly into a rib, so there is no overlap of, or gap between, the ends 512 , 514 of the inner and outer segments. In other implementations, however, there could be a gap between the ends 512 , 514 of the inner and outer segments.
FIG. 8 is an expanded view of a rib-and-groove feature 500 including a series of cross-sections 600 , 602 , 604 , 606 , 608 , 610 , 612 . As shown in the cross-sections, the rib-and-groove feature 500 may include a curved trough or a generally V-shaped notch 616 with a rounded tip 614 that extends downward from the concave surface 302 of the roll toward the interior of the enclosure in the inner segment 502 (groove portion) and upward from the convex surface 300 of the roll away from the interior of the enclosure in the outer segment 504 (rib portion). Various geometries are possible for the notch, including without limitation a square-shaped notch with rounded edges. Other geometric aspects of the notch, including the curvature and angle of the notch and the radius of the rounded tip, may be constant or may vary along the length of the rib-and-groove feature 500 . The depth and height of the rib-and-groove feature 500 relative to the roll may vary as the notch traverses from the inner edge 306 to the outer edge 308 of the roll. For example, the maximum depth of the inner segment 502 (the groove portion) may be at the midpoint between the inner edge 306 and the apex of the roll. In other words, the groove presented by the inner segment 502 may be deepest halfway between the apex and the inner edge 306 . The maximum height of the outer segment 504 (the rib portion) may be at the outer edge 308 of the roll, and the minimum height may be at the inner end 514 (the end proximate to the apex of the roll). In other words, the rib presented by the outer segment 504 may be tallest at the outer edge 308 of the roll. A transition radius may be provided at the boundary between the rib-and-groove feature 500 and the roll, in lieu of sharp edges. It should be understood that a wide variety of variations could be implemented and symmetry need not be maintained. For example, the extent to which the inner and outer segments 502 , 504 protrude from the concave and convex surfaces of the suspension element may vary. Further, the cross-sections of maximum and minimum height and depth between the inner segments and outer segments are not necessarily equal in magnitude, and the point where the inner segment 502 and outer segment 504 are deepest and tallest, respectively, may vary. Moreover, in some examples, the depth of the inner segment 502 and the height of the outer segment 504 may remain constant over a large portion of their length. In other examples, the inner and outer segments 502 , 504 may have a plurality of local maxima and minima along their path.
The different types of radial features may be presented alone or in any combination, and in any suitable number, spacing, pattern and ratio. FIGS. 1 and 2 , for example, illustrate a suspension element with radial groove features in alternation with radial rib-and-groove features. But a wide variety of modifications and variations of the radial features are possible. For example, a suspension element may have radial rib features in alternation with radial rib-and-groove features, or may have all three radial features (ribs, grooves and rib-and-groove features). Moreover, the radial features need not be presented in alternation, but could be presented in any proportion, e.g., rib-and-groove features 500 could be presented every third, fourth, fifth (or any suitable number) radial feature.
Adjacent ribs, grooves and/or rib-and-groove features are separated by a pitch distance, which can be defined as a circumferential distance taken at a specified radial distance from the origin. For convenience, the distance will be defined at the midpoint between the inner and outer edges of the suspension element. The pitch distance between adjacent ribs, grooves and/or rib-and-groove features may vary. In some examples, the pitch distance is uniform for all of the successive pairs of ribs, grooves and/or rib-and-groove features around the circumference of the suspension element, so that the features are regularly spaced. In other examples, the pitch distance could vary between successive pairs.
The path of the grooves, ribs and rib-and-groove features may be straight or may comprise a plurality of sections and a plurality of transition regions. The angle of orientation of each section, where angle of orientation is defined as the angle of the section at the point along the section closest to the inner edge, to a normal to the inner edge that intersects the closest point, as well as the radius of curvature of the path section, can vary. The radius of curvature of the path section can vary over the section. Transition regions can smoothly join the ends of adjacent path sections. For the case where the radius of curvature at the end of one section and the beginning of the section to which it is joined have opposite sign, the transition region may include an inflection point. The number of inflection points in a groove, rib, or rib-and-groove feature path may vary.
The rib, groove and rib-and-groove features described above provide added stiffness in the primary axis of vibration (Z-axis). More particularly, the outer segments 504 (the rib portions) of the rib-and-groove feature 500 provide additional axial stiffness in the direction of the interior of the enclosure. In general, a suspension element having only radial grooves can undergo greater excursion without non-circumferential distortion in comparison with a suspension element of similar dimensions and materials, but without radial grooves. FIG. 9 illustrates an exemplary force versus displacement curve for such a suspension element. Note the asymmetry of the curve in different directions of excursion, e.g., +2.9 N of force at +6.0 mm excursion and −1.4 N of force at −6.0 mm of excursion. Suspension element 104 can undergo similar excursion without non-circumferential distortion, and also exhibits more symmetrical force versus displacement in comparison with a suspension element with only radial grooves. FIG. 10 illustrates an exemplary force versus displacement curve for the suspension element 104 . Note the enhanced symmetry of the curve in different directions of excursion, e.g., +3.2 N of force at +6.0 mm excursion and −3.4 N of force at −6.0 mm of excursion.
Among the wide variety of variations that are contemplated are variations of placement of the radial features. For example, the number of radial features, spacing between radial features and all dimensions of radial feature geometry could be varied. Further, the radial features are not limited to grooves and rib-and-groove features, but may also include ribs, and more than two different types might be utilized. Further, all of the radial features could be characterized by inflexions of concavity, e.g., in a manner similar to that of the rib-and-groove features 500 . The ends of the radial features could be in any of various locations. In one example, the rib-and-groove features 500 traverse the roll from approximately the inner edge 306 to the outer edge 308 whereas the groove features 304 traverse the roll from a point offset from the inner edge 306 to the outer edge 308 . Moreover, the maximum extent of the radial features could be varied, and transitions from zero protrusion to the maximum extent could be defined by any of various mathematical functions. Further, material thickness could be varied at the radial features and within individual radial features. For example, referring to FIG. 11A , in examples where the rib-and-groove feature 500 has a substantially uniform thickness, the outer segment 504 of the rib-and-groove features 500 may extend onto the outer landing 312 (as shown in FIG. 6B ). Consequently, a perimeter defined by the outer edge 308 of the suspension element 104 may be non-circular, including V-shaped protrusions (as shown in FIG. 2 ). These V-shaped protrusions may be undesirable from the standpoint of manufacturability. Thus, in some implementations, as shown in FIG. 11B , the material used to create the suspension element 104 is under-compressed at least at the portion 702 where the outer segment 504 meets the outer landing 312 of the suspension element 104 , thereby eliminating the V-shaped portions. Accordingly, the rib-and-groove feature 500 has varying material thickness along the length of the outer segment 504 (the rib portion). More particularly, the rib-and-groove feature 500 has increased material thickness in at least a portion 702 of the outer segment 504 proximate to the outer landing 312 .
A number of implementations have been described in the above examples, but it will be understood by those of ordinary skill in the art that a wide variety of modifications and variations are possible without departing from the concepts herein disclosed. Moreover, all examples, features and aspects can be combined in any technically possible way. Accordingly, other implementations are within the scope of the following claims. | An apparatus includes a suspension element coupling a first rigid element to a second rigid element such that the first rigid element is movable in a reciprocating manner relative to the second rigid element. The suspension element includes radial features, some of which may have radial segments of opposite concavity. The segments with opposite concavity provide added stiffness in the primary axis of vibration and may contribute to a more symmetrical force-deflection relationship. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
BACKGROUND
[0003] The various embodiments and aspects discussed herein relate to an apparatus for blocking unwanted calls. Telephone marketing over the years has grown into a multibillion-dollar industry. As such, companies will call a large number of homes either through machine automation or with the help of live people. Unfortunately, homeowners do not want to be bothered by these telemarketing calls. Moreover, these calls are typically made when the families do not want to be bothered such as dinnertime. Prior art call blocking apparatuses exists but may be complicated to use and ineffective at blocking unwanted calls.
[0004] Accordingly, there is a need in the art for an improved call blocking apparatus.
BRIEF SUMMARY
[0005] The various aspects and embodiments described herein address the needs discussed above, discussed below and those that are known in the art.
[0006] An apparatus for blocking unwanted calls is disclosed. The apparatus may be connected to the telephone in series or in parallel in the home. Regardless, the apparatus intercepts a telephone signal and determines whether the caller ID information contained in the telephone signal is found on a whitelist, blacklist or on neither lists. If the caller ID is on the whitelist, then the call is not interrupted and the telephone signal is allowed to access the telephone so that the user may answer the telephone. If the caller ID is on the blacklist, then the telephone signal is not allowed to access the telephone and the apparatus may hang up on the caller. If the caller ID is on neither the blacklist or the whitelist, then the caller is presented with a message that indicates that should the caller be a telemarketer or solicitor, the caller should hang up or if the caller is not a telemarketer or solicitor that the caller should press zero. If the apparatus detects a zero tone, then the telephone signal is allowed to access the telephone so that the telephone may ring and the user may pick up the call.
[0007] More particularly, an apparatus for blocking unwanted telephone calls is disclosed. The apparatus may comprise a line input, a line output and a processor. The line input may be attached to a telephone jack for receiving a telephone signal which includes a caller id. The line output may be attached to a telephone having a caller id capability. The processor may perform the steps of receiving the telephone signal including the caller id information; comparing the caller id information to a whitelist; and ringing the telephone if the caller id information is matched to a telephone number on the whitelist.
[0008] The steps of the processor may further comprise blocking the telephone signal from the telephone if the caller id information is matched to a telephone number on a blacklist; and presenting a preprogrammed new message to the incoming caller if the caller id is not matched to a telephone number on either of the blacklist or the whitelist.
[0009] The processor further performs the steps of presenting one caller id information to the user from a list of new caller id information; adding the presented caller id information to the whitelist if the user depresses an accept button; and adding the presented caller id information to the blacklist if the user depresses a reject button.
[0010] The processor may further perform the steps of blocking the telephone signal from the telephone if the telephone signal does not include caller id information.
[0011] The preprogrammed new message may indicate that the caller should hang up if the caller is a telemarketer, or press a number on a keypad of the telephone.
[0012] The processor may further perform the steps of deleting one telephone number from a master list of caller IDS, blacklist or whitelist by depressing a delete button.
[0013] In another aspect, a home with a telephone system for blocking unwanted telephone calls is disclosed. The home may comprise a communication link, a first telephone jack, a first telephone cable, an apparatus and a first telephone. The communication link may be in communication with a telephone company for receiving a telephone signal from the telephone company. The first telephone jack may be in communication with the telephone link for providing the telephone signal to an interior of the home. The first telephone cable may be connected to the first telephone jack. The apparatus may block unwanted telephone calls. The apparatus may be in communication with the first telephone cable for receiving the telephone signal. The apparatus may comprise a processor performing the steps of receiving the telephone signal including caller id information; comparing the caller id information to a whitelist; ringing the telephone if the caller id information is matched to a telephone number on the whitelist; a first telephone in communication with the apparatus and controlled by the apparatus. In this setup, the apparatus and the first telephone are connected to each other in series.
[0014] The home may further comprise a second telephone jack in communication with the telephone link for providing the telephone signal to the interior of the home. A second telephone cable may be connected to the second telephone jack. A second telephone may be in communication with the second telephone cable so that the second telephone is connected to a telephone system of the home in parallel to the first telephone.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which:
[0016] FIG. 1 is a perspective view of an apparatus for blocking unwanted calls;
[0017] FIG. 2 is a first schematic diagram for setting up the apparatus and telephone in a home;
[0018] FIG. 3 is a second schematic diagram for setting up the apparatus and telephone in the home;
[0019] FIG. 4 is an operational flowchart for handling incoming calls received by the apparatus; and
[0020] FIG. 5 is a flowchart for assigning and deleting caller IDs from a whitelist, blacklist or a master list of caller IDs.
DETAILED DESCRIPTION
[0021] Referring now to the drawings, an apparatus 10 for blocking unwanted telephone calls that is easy to use and works is disclosed. The apparatus 10 accepts all incoming calls and compares the incoming caller identification (ID) to a whitelist of caller IDs. If the incoming caller ID is not found on the whitelist of caller IDs, then the call is not allowed to access the telephone 12 and the caller is presented with a pre-recorded message that indicates that he or she should hang up if the caller is a telemarketer or solicitor of any kind or press zero. Friends and family that call the user's telephone and that are on the whitelist will not hear the pre-recorded message. The call is allowed to access the telephone 12 without the pre-recorded message prompt so that the user (i.e., homeowner) may easily answer the call. Thereafter, the user may add the caller ID of the friend or family to the whitelist of caller IDs by depressing an add to whitelist buttton. If the caller hangs up, then the user may easily add the caller ID of the telemarketer to the blacklist of caller IDs by depressing an add to blacklist button. Due to the whitelist and blacklist of caller IDs, friends and family are interrupted only once by the pre-recorded message while Robo calls are always blocked and telemarketers are significantly discouraged and effectively do not press zero.
[0022] Referring now to FIG. 1 , the apparatus 10 has a display 14 and a plurality of buttons 16 - 26 . The buttons 18 - 26 are used to access a master list of caller IDs, the whitelist of caller IDs, the blacklist of caller IDs and to add or delete a caller ID from the whitelist, blacklist and master list. The button 16 is used to select a language for the message. The apparatus 10 additionally has two phone jacks 28 , 30 .
[0023] Referring now to FIG. 2 , the phone jack 28 may be in electrical communication with the phone jack 32 that comes into the home 34 from the phone company 36 . The phone jack 30 may be in electrical communication with the telephone 12 in series. In this setup, the apparatus 10 receives all calls coming in through the phone jack 32 and does not allow the telephone signal to ring the telephone 12 . The apparatus 10 either (1) allows the caller ID from the telephone signal to reach the telephone 12 and be displayed on the telephone display or (2) sends only the caller ID read from the telephone signal to the telephone 12 without ringing the telephone 12 . Additional telephones 12 may be connected to other phone jacks 32 located in the home 34 . When a telephone signal comes into the home 34 via the telephone company 36 , the telephone signal is received by the apparatus 10 and the telephone 12 which is directly connected to the phone jack 32 shown in dash lines in FIG. 2 does not ring. The telephone 12 directly connected to the phone jack 32 at other locations in the house rings only once. The apparatus 10 retrieves the caller ID from the telephone signal which is compared to the whitelist and blacklist in the apparatus 10 . If the caller ID is matched to a number on the whitelist, then the telephone signal is allowed to continue ringing the telephone 12 directly connected to the phone jack 32 at other locations in the house and the telephone 12 directly connected to the apparatus 10 . If the caller ID is matched to a number on the blacklist, then the telephones 12 are not allowed to ring and the call is terminated by the apparatus 10 . The telephone 12 is directly connected to the other jacks 32 throughout the home 34 may ring only once. Thereafter, the apparatus 10 blocks the call. If the caller ID is new, then the apparatus 10 prompts the caller with the pre-recorded message.
[0024] Other configurations are also contemplated. By way of example and not limitation, referring now to FIG. 3 , the apparatus 10 may be in electrical communication with phone jack 32 . A telephone 12 is not directly connected to the apparatus 10 . Instead, the telephone 12 may be connected to a different phone jack 32 in the home 34 . When the telephone signal comes in from the phone company 36 , the telephone signal is received by both the apparatus 10 and the telephone 12 . As such, the telephone 12 rings once. The apparatus 10 retrieves the caller ID information from the telephone signal which is compared to the whitelist and blacklist in the apparatus 10 . If the caller ID is matched to a number on the whitelist, then the telephone signal is allowed to continue ringing the telephone 12 . If the caller ID is matched to a number on the blacklist, then the telephone is not allowed to ring and the call is terminated by the apparatus 10 . If the caller ID is new, then the apparatus 10 does not allow the telephone 12 to ring and prompts the caller with the pre-recorded message. The apparatus 10 may be placed in series (see FIG. 2 ) with the telephone 12 . Alternatively, the apparatus 10 may be placed in parallel (see FIG. 3 ) with the telephone 12 .
[0025] Referring now to FIG. 4 , a flowchart of the steps that the apparatus 10 takes when receiving a telephone signal is shown. The apparatus 10 receives 100 the telephone signal from the telephone company 36 through the phone jack 32 . The apparatus 10 then determines 102 the caller ID from the telephone signal. If the telephone signal does not contain a caller ID, then the apparatus 10 hangs up 104 on the caller. Alternatively and optionally, the apparatus 10 may answer the call and provide a different pre-recorded message that the call is being hung up 104 since the caller has a blocked caller ID and that should the caller desire to speak to the homeowner, then the caller should unblock their caller ID. After presenting the caller with such message, then the apparatus 10 may hang up 104 on the caller.
[0026] Provided that the telephone signal contains the caller ID information, the apparatus 10 retrieves the caller ID information and compares 106 the caller ID in the telephone signal to the caller IDs on the whitelist and the blacklist If the caller ID is matched 108 to a number on the whitelist, then the apparatus 10 allows the telephone signal to access the telephone 12 so that the telephone 12 will ring 110 and the user can answer the call. If the caller ID is matched 112 to a number on the blacklist, then the apparatus 10 either hangs up 114 or may optionally play 116 the pre-recorded blacklist message discussed above then hang up 118 . If the caller ID is not matched to a number on the whitelist or the blacklist but is a new number 120 , then the apparatus 10 prompts the caller with the pre-recorded new message. The new message states that if the caller is a telemarketer or solicitor that he or she should hang up 114 , or press zero if he or she is not a telemarketer or solicitor. After playing the new message, the apparatus 10 listens 122 for a tone. If the apparatus 10 detects that the zero button or the tone indicated in the message has been depressed, then the apparatus 10 allows 124 the telephone signal to access the telephone 12 .
[0027] Referring now to FIGS. 1 and 5 , the apparatus 10 reads the caller ID from the telephone signal of all the incoming calls. It places all of the caller IDs on a master list of caller IDs which is shown on the display 14 . The user may scroll up or down the list (i.e., review 126 list of caller IDs) by depressing the up button 24 or the down button 26 . For each of the caller IDs, the display 14 will indicate whether the caller ID is on the whitelist, blacklist or on neither lists (i.e., new). If the caller ID is on the whitelist, then the display 14 will show the word “ACCEPT”. If the caller ID is on the blacklist, then the display 14 will show the word “REJECT”. If the caller ID is neither on the whitelist or the blacklist, then the display 14 will show the word “NEW”. If the caller ID is new, then the user may place the caller ID on the whitelist by depressing 128 the whitelist button 18 or place the caller ID on the blacklist by depressing 130 the blacklist button 20 . The user may also delete the caller ID from the whitelist, blacklist or the master caller ID list by scrolling to the number by depressing the up or down buttons 24 , 26 and depressing 132 the delete button 22 .
[0028] The apparatus 10 may optionally have three language presets. By way of example and not limitation, the apparatus 10 may present the messages in English, Spanish or German. The language may be selected by depressing the voice button 16 one or more times. For English, the letter A will be shown on the display 14 . For Spanish, the letter B will be shown on the display 14 . For German, the letter C will be shown on the display 14 . Other languages are also contemplated.
[0029] Optionally, the apparatus 10 may also have the capability of allowing the user to record his or her own voice so that the messages provided to the callers are in the homeowner's own voice. To this end, the apparatus 10 may be supplied with power 38 to operate the microphone 40 . The apparatus 10 may prompt the user to speak into the microphone 40 to record the messages to be provided to the caller during operation of the apparatus 10 . The apparatus 10 may also have memory and a processor to store the prerecorded messages or personalized messages of the user which are provided to the caller during operation of the apparatus 10 .
[0030] The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including various ways of arranging the buttons 16 - 26 . Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments. | An apparatus for blocking unwanted calls is disclosed. The apparatus incorporates a whitelist which the user can program so that known friendly callers are not interrupted by the apparatus. The apparatus also incorporates a blacklist which automatically rejects known unwanted callers so that the user is not interrupted by these calls. Additionally, the apparatus allows the user to easily add new numbers to either the blacklist or white list and also to delete numbers from the white list, blacklist or master list of caller IDs. For new numbers, callers are presented with a simple but yet effective message that states that the caller should hang up if the caller is a solicitor or telemarketer, or otherwise press zero so that the apparatus can allow the call to go through to the telephone. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/643,747, filed May 7, 2012, hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to ultrasound modulation of the brain and more particularly relates to a method for ultrasound modulation of the brain for treatment of stroke, brain injury, and other neurological disorders.
[0004] 2. Description of the Related Art
[0005] Causes of brain damage include stroke, traumatic brain injury (TBI), and other disorders of the brain that require the brain to remap its function and organization. Physical therapy is generally the standard treatment for brain injury. However it is a long, tedious, and expensive process whose outcome is often far from satisfactory.
[0006] Electrical stimulation applied to the brain cortex for treatment of brain damage has been under investigation for many years and it has been shown to be effective in improving patient outcomes of physical therapy. The exact mechanism of its therapeutic effect in the brain is unknown but thought to be a result of producing a subthreshold excitation of brain cells that enables them to more readily change in their synaptic connections and functionality. The effects may include facilitated learning and may last for long periods of time.
[0007] Electrical energy however needs to be applied locally to the brain tissue to areas that are relearning with therapy. Reported electrical methods such as those of Northstar Inc. generally require electrodes to be directly placed locally on or near portions of the brain that are expected to change in their function by remapping.
[0008] The process of brain remapping for lost function is evoked by patient physical therapy. Other approaches include transcranial magnetic stimulation (TMS) that, although noninvasive, fails to provide the needed localization of induced electrical stimulatory effects on the brain. Studies have shown that TMS is able to produce a lasting change in neural activity within the cortex that persists after terminating the treatment. Transcranial electrical stimulation (TES) also cannot provide location-specific current delivery in the brain and may also produce pain.
[0009] Functional changes that occur in the brain are a result of a re-learning nature of brain cells to perform new functions, called neural plasticity. There is an invasiveness to electrical devices that limits their application because highly invasive surgery is required to access the brain.
[0010] Biological tissues are known to be responsive to other forms of applied energy. It is known that ultrasound energy has effects on the brain and nervous tissues. For example, U.S. Pat. No. 7,702,395 to Towe et al. discloses an application of high frequency ultrasound energy used in medical imaging that affect changes in neural excitability. Ultrasound at considerably lower frequencies than used in ultrasound medical imaging has bioelectrical effects on the brain as evidenced by the production of muscle action events.
[0011] Ultrasound applications have been described in the patent literature for bioelectrical stimulatory effects on the brain. The reason for the ultrasound effectiveness in creating neural effects is a matter of current scientific debate. A popular theory is that there is a type of cell membrane stretch activation that results from the compression-rarefaction nature of ultrasound; another is that there is a cavitation or stirring effect that affects sodium channels.
[0012] There are also different effects on excitable tissues depending on the ultrasound pulse protocol. For example on nerve axons the effects of relatively slowly repeating ultrasound pulses of high peak amplitude effects are inhibitory where the effects of high amplitude fast repeating ultrasound pulses are excitatory.
[0013] Stroke is neurological damage resulting from a restricted blood flow to the brain caused by emboli, hemorrhages, or clotting that causes a diminished brain function according to the function of the region where the blood flows. Surviving patients are usually subjected to physical therapy to retrain healthy parts of the brain to regain some loss of function of a limb or another affected body part. By repetitive physical motion of limbs, practicing speech, or other training methods, undamaged parts of the brain re-map at least some of their functionality to restore lost function. Unfortunately, physical therapy is a long process and is not always effective.
[0014] It is known that applying electrical energy to the brain can affect its relearning after brain damage. For example, low levels of TMS stimulation, where movement was not induced in neuro-block models that mimic amputation, is able to modify the lasting changes in neural activity that normally accompany amputation.
[0015] Electrical stimulation methods have been used for accelerating the process of stroke rehabilitation. This is performed by applying electrical currents to brain regions surrounding the stroked area and in combination with a physical therapy whereby the patient attempts to exercise the lost functionality.
[0016] Electrical current applied to brain tissue, even when applied to regions that are neuroplastic, however is not sufficient to achieve therapeutic benefits. Rather it is a combination of applying the electrical energy with physical therapy whereby the patient actively attempts to exercise lost function such as muscle control, speech, or other body function. One problem with application of electrical energy is that currents must be localized and so this requires invasive techniques. This is typically performed through the use of electrode arrays implanted in the brain connected to an implanted or external electrical pulse generator. Implantation of these devices involves trauma to the patient, risks of surgery, and high expense. The device may not be easily removable when the process of neuroplastic change is complete.
[0017] Local electrical application to the brain also requires a relatively high current drain on batteries to stimulate a relatively large amounts of cortex; depending on the tissue volume that is being treated. This lends to weight and bulk to any implantable neuroprosthesis making it uncomfortable and even impractical in some cases.
SUMMARY OF THE INVENTION
[0018] A method is presented for ultrasound therapy of the brain for treatment of stroke, brain injury, and other neurological disorders. In some embodiments, the method includes identifying a stimulation site of a brain, where the stimulation site is associated with a brain disorder, applying ultrasound to the stimulation site, and initiating exercise of the parts of the brain involved, such as through physical therapy. In some embodiments, identifying the stimulation site of the brain may include providing a diagnostic brain image of a patient. Furthermore, identifying the stimulation site of the brain may include selecting a stimulation site from the diagnostic brain image.
[0019] In some embodiments, identifying the stimulation site of the brain may include assessing a symptom, functional change, or functional characteristic associated with the brain (e.g. that can be correlated to the known structure-function relationships of the brain) to identify the stimulation site. In some embodiments, applying ultrasound to the stimulation site may include varying ultrasound parameters. This application of ultrasound in combination with a corresponding therapy to the patient may be effective in producing neuroplastic events. The exercise of the targeted brain functionality may be invoked coincident with the application of ultrasound and continue while the ultrasound is in continuous application according to the above parameters. In some embodiments, the exercise may be applied following the ultrasound application over a duration of, for example, 1 minute to 10 minutes. The exercise of the faculty may also follow immediately after cessation of the ultrasound.
[0020] In some embodiments, applying ultrasound to the stimulation site may include applying a plurality of ultrasound generators to the patient's head proximate to the stimulation site. In addition, applying ultrasound to the stimulation site may include focusing ultrasound beams such that the ultrasound beams intersect at the stimulation site. In some embodiments, applying ultrasound to the stimulation site may include implanting ultrasound transducers under the scalp of the patient. Furthermore, applying ultrasound to the stimulation site may include implanting transducers under the patient's skull.
[0021] In some embodiments, applying ultrasound to the stimulation site may include providing ultrasound in the frequency range of 100 kHz to 1 MHz, which may transfer the sound noninvasively through the skull. In some embodiments, ultrasound may be applied at frequencies of 1 MHz to 10 MHz. In some embodiments, an ultrasound transducer may be placed external to the scalp, under the scalp, and/or under the skull bone. In addition, applying ultrasound to the stimulation site may include providing ultrasound pulses having a duration in the range of 10 milliseconds to 1000 milliseconds, and may have a duration in the range of 10 milliseconds to 300 milliseconds and have pulse duty cycles on the order of 1-10%, for example, such that the mechanical index (MI) of the ultrasound and thermal index (TI) of ultrasound may be within legal regulatory limits.
[0022] In some embodiments, applying ultrasound to the stimulation site may include repetition rates in the range of 0.1 Hz to 100 Hz, 1 Hz to 30 Hz, or 5 Hz to 10 Hz. In addition, in some embodiments, applying ultrasound to the stimulation site may include applying ultrasound in sets of pulses, where the pulse duration is between 100 milliseconds to 200 milliseconds long and the sets are repeated at a rate of 0.01 Hz to 25 Hz for durations as short as one group of pulses to continuous duty as long as the exercise of the brain continues.
[0023] In some embodiments, applying ultrasound to the stimulation site provides an ultrasound spatial peak temporal average (SPTA) amplitude greater than 0.01 watt/cm2 and less than or equal to 180 mW/cm2. In some embodiments, applying ultrasound to the stimulation site may raise the expected resting potential of a population of neurons at the stimulation site by approximately 10% to 80% of a difference between the expected resting potential and an action potential for the population of neurons.
[0024] In some embodiments, applying ultrasound to the stimulation site may include applying ultrasound stimulation to the motor cortex sufficient to cause a physically noticeable motor activity. In addition, applying ultrasound to the cortical stimulation site may include reducing the power of the ultrasound stimulation by a predetermined amount and then exercising the desired faculty in accordance with the procedure outlined above. For example, the predetermined amount may be 50% from its peak value that directly stimulates the faculty. In another embodiment, ultrasound is applied coincident with the patient strongly imagining physical movement of the affected portion of the body, which may be used if actual movement is not possible.
[0025] In some embodiments, initiating the exercise occurs later in time than applying ultrasound to the stimulation site.
[0026] The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically.
[0027] The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise.
[0028] The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
[0029] Other features and associated advantages will become apparent with reference to the following detailed description of specific embodiments in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the detailed description of specific embodiments presented herein.
[0031] FIG. 1 is a flow chart illustrating one embodiment of a method for providing ultrasound modulation of the brain for treatment of stroke, brain injury, and other neurological disorders.
[0032] FIG. 2 is a flow chart illustrating one embodiment for identifying a stimulation site.
[0033] FIG. 3 is a flow chart illustrating another embodiment for identifying a stimulation site.
[0034] FIG. 4 is a schematic block diagram illustrating a method for providing ultrasound modulation of the brain.
[0035] FIG. 5 is a graph showing ultrasound pulse durations and repetition rates.
[0036] FIG. 6 is a graph showing the amplitude applied in some embodiments for providing ultrasound modulation of the brain.
DETAILED DESCRIPTION
[0037] Various features and advantageous details are explained more fully with reference to the nonlimiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well known starting materials, processing techniques, components, and equipment are omitted so as not to unnecessarily obscure the invention in detail. It should be understood, however, that the detailed description and the specific examples, while indicating embodiments of the invention, are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and/or rearrangements within the spirit and/or scope of the underlying inventive concept will become apparent to those skilled in the art from this disclosure.
[0038] Therapeutic methods are disclosed that do not apply electrical current directly to the brain. Moderate levels of ultrasound energy applied to the brain concurrent with physical therapy can be used as a method to accelerate the remapping of the brain to more rapidly recover lost neurological function. The ultrasound energy and physical therapy may promote brain plasticity.
[0039] The physiologic mechanism by which ultrasound affects this remapping process is unknown. It may be for example that ultrasound affects brain cells through pressure wave stirring and flexure movements at the fundamental level of the cell membrane where remapping and remodeling events ultimately occur. Stretch activation processes may occur at the membrane and initiate cellular processes through intermediary bioelectrical events that are dedicated to creating new connections and functionality of the cell. It is believed that ultrasound effect is intrinsically inhibitory while at higher duty cycles there is a transient thermal rise in tissue that becomes excitatory. Thus it is possible to apply ultrasound in multiple ways to excitable tissue to cause different outcomes.
[0040] Some of the methods disclosed require an ability to localize the brain region that is candidate for ultrasound-promoted neural plasticity. This may be defined by a physician but typically is at the edges of the damaged region of the brain. The indiscriminate application of ultrasound to the brain globally, or in a focused manner at a specific location will be ineffective except when the brain is exercising the functionality associated with the specific location. Physical therapy activates portions of the brain, for example, the motor and pre-motor cortex to be receptive to remodeling. These exercises may be guided by a therapist, guided by robots, the patient, or even where the patient strongly imagines to be utilizing the lost function. The combination of ultrasound therapy and physical therapy may promote improved brain remapping. In other applications, accelerated remapping of the brain may be desirable as a type of learning tool and in order to promote its enhanced functioning through ultrasound application. This may make up for deficits that are associated with pathology or promote the improved functionality of an otherwise normal brain. For example, application of ultrasound to the frontal regions of the brain may be used in combination with desirably intense voluntary exercise of this part of the brain. Such exercises will then lead to neuroplastic changes leading to increased rate of learning, improved attention, and/or improved memory as these are known functions of this part of the brain.
[0041] As a method of treating brain damage, this may require ultrasound application to the parts of the brain that will naturally remap in function to take over the function of the parts of the brain that were lost to damage. The determination of the damaged parts of the brain is generally performed by imaging such as PET, MR, CT, etc. The physician then uses his experience and taking into account the known ways that the brain recovers from such damage in order to apply ultrasound to still-functional parts of the brain where re-mapping is occurring. The ultrasound is not causing the remapping of the brain but rather promoting a natural neuroplastic process.
[0042] Some of the methods disclosed herein also monitor the effects of pulsed ultrasound on the brain as a method and tool useful in determining the ultrasound intensity and pulse parameters needed to be effective. It employs ultrasound evoked neural field potentials. Changes in brain neural field potentials are associated with a class of bioelectric responses known as evoked responses. There are for example, visual, auditory, somatosensory evoked bioelectrical responses monitored from the brain that result from corresponding stimuli to these senses.
[0043] The ultrasound energy pulse protocols needed to achieve neural plasticity effects may additionally use a dose reference point of pulse parameters required to achieve specific action events in the brain, such as evoked skeletal muscle events. After a skeletal muscle event is detected in response to an amplitude of ultrasound stimulation, the ultrasound energy may be reduced by 40% to 80%, for example, to achieve therapeutic neuroplastic effects.
[0044] The schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown.
[0045] FIG. 1 shows method 100 for promoting brain remapping. The method 100 begins with 102 identification of a stimulation site associated with a brain disorder. In some embodiments the stimulation site may be the portion of the brain that has suffered pathology, but in some embodiments the stimulation site may be a portion of the brain that is learning to perform functions previously performed by the damaged portion. After the stimulation site is identified, the method 100 applies ultrasound to the stimulation site 104 . Ultrasound may be provided, for example, by a piezoelectric transducer. Method 100 also includes the step of initiating physical therapy 106 . In some embodiments, the physical therapy is provided simultaneously with the ultrasound, while in other embodiments the physical therapy may be provided after the ultrasound energy. For example, five minutes or more may elapse between the application of ultrasound to the stimulation site and the physical therapy.
[0046] FIG. 2 shows a method 200 for identifying a stimulation site of a brain 102 . In this method, a diagnostic brain image of a patient is first provided 202 . The diagnostic brain image may include a map of neural activity in the brain such as a fMRI, PET, or TMS. The method 200 also includes step 204 , where a stimulation site is selected from the diagnostic image 204 . A stimulation site is a site where a change in the natural remapping of the brain is expected to occur. The diagnostic image may identify a portion of the brain that is damaged, or portions of the brain that may be able to learn to perform functions lost by the damaged portion.
[0047] FIG. 3 shows an alternative method, method 300 , for identifying a stimulation site of a brain 102 . In this method, a symptom, functional change, or functional characteristic with a brain disorder is assessed 302 . For example, a particular limb may be observed to have reduced functionality due to a brain disorder. At step 304 , the method includes the identification of a location of a brain associated with the symptom, functional change, or functional characteristic. For example, if a particular limb is observed to have reduced functionality, the particular portion of the brain responsible for that functionality may be identified. Finally, the stimulation site may be identified in response to identifying the location of the brain associated with the symptom, functional change, or functional characteristic.
[0048] FIG. 4 shows a schematic representation of the application of ultrasound to the stimulation site. Pulse generator 402 produces electrical signals that are provided to the ultrasound transducer 404 . The ultrasound transducer 404 may be a piezoelectric transducer, for example. In response to the electrical signals from the pulse generator 402 , the ultrasound transducer 404 creates ultrasound signals 406 that stimulate brain 408 at the stimulation site 410 . In this figure, only one ultrasound transducer is shown. However, in some embodiments, a plurality of ultrasound transducers may be used to stimulate one or more stimulation sites simultaneously. For example, two ultrasound transducers may be configured to emit ultrasound signals 406 from two different locations, and the ultrasound signals may intersect at the stimulation site 410 . In some embodiments, signals 412 from the brain 408 may be detected by sensor 414 , which may in turn be use by pulse generator 402 to modulate the ultrasound signals 406 .
[0049] In some embodiments, the ultrasound transducer 404 may be implanted under the scalp, but outside the skull of a patient. The transducer 404 may be connected to a pulse generator 402 that is battery powered and implanted underneath the scalp. Alternatively, the pulse generator 402 may be inductively coupled to the ultrasound transducer 404 through the skin. In some embodiments, the ultrasound transducer may be implanted inside a patient's skull and provide ultrasound energy through the brain dura and/or pia. If the ultrasound transducer is implanted inside the patient's skull, there may be increased accuracy in the location and amplitude of applied ultrasound. However, implanting an ultrasound transducer increases the invasiveness of the method.
[0050] FIG. 5 shows a simplified representation 500 of ultrasound pulses that can be used to provide ultrasound energy in the methods disclosed herein. In this example, there are two sets 506 of pulses 502 . The pulses 502 within a set 506 are separated by a space in time 504 . In some embodiments, the pulses may be square waves as shown in FIG. 5 . However the pulses may have different shapes such as a sinusoidal shape, and may vary in pulse amplitude, width, and repetition rate. The frequency of ultrasound pulses 502 may be in the range of 200 kHz to 999 kHz. Moreover, the ultrasound pulses may have a duration (on-time) in the range of 10 milliseconds to 1000 milliseconds. In some embodiments, the pulses have a duration in the range of 100 milliseconds to 300 milliseconds.
[0051] As shown in FIG. 5 , the application of ultrasound pulses may not be continuous. There may be a period 508 between applications of ultrasound pulses. The period 508 may be the time between individual pulses 502 , or may be the time between sets 506 of pulses 502 . The period 508 may vary between about 10 milliseconds to about 10 seconds, which corresponds to a repetition rate of about 0.1 Hz to 100 Hz. In some embodiments, the repetition rate may be between 1 Hz and 30 Hz, or 5 Hz and 10 Hz. The sets 506 of pulses may have a duration between 100 and 200 milliseconds. Furthermore, the repetition rate may be between 0.01 Hz to 5 Hz.
[0052] The use of sets 506 of pulses 502 may help keep temperatures down. The frequency of pulses 502 within a set 506 may be in the range of 300 Hz and lower for neurological inhibitory effects and 3 kHz or higher for excitatory effects. An average power of less than 180 mW/cm 2 may achieve neurologically suppressive effects to treat maladaptive plasticity but reduce or eliminate tissue damage.
[0053] The ultrasound pulses, as described above, may raise the expected resting potential of a population of neurons at the stimulation site by approximately 10% to 80% of a difference between the expected resting potential and an action potential for the population of neurons. Therefore, neurons may become more sensitive, which improves neural plasticity.
[0054] FIG. 6 shows a graph representing neurostimulation using ultrasound. The amount of ultrasound provided to a stimulation site is ramped up 602 until a the ultrasound stimulation causes a physically noticeable motor activity at the peak value 604 . For example, a skeletal muscle may move in response to the ultrasound stimulation. After the motor activity is observed, the power of the ultrasound signal may be reduced. In some embodiments, the power may be reduced by about 50%, which will not produce additional motor activity, but will increase neural plasticity.
[0055] All of the methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the apparatus and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. In addition, modifications may be made to the disclosed apparatus and components may be eliminated or substituted for the components described herein where the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope, and concept of the invention as defined by the appended claims. | A method for ultrasound modulation of the brain for treatment of stroke, brain injury, and other neurological disorders or the improvement of cognitive functioning in patients. The method may include identifying a stimulation site of a brain, where the stimulation site is associated with a brain disorder, applying ultrasound to the stimulation site, and initiating physical therapy. Alternately, ultrasound may be applied to the brain to enhance aspects of cognitive functioning by the combination of exercising the functionality of the brain and applying ultrasound to the region(s) or structures of the brain known to be associated with that function. | 0 |
FIELD OF THE INVENTION
The present invention relates to the field of treating abnormal eye inflammation and more particularly to the topical treatment of inflammations and other dysfunctions of the eyelid and conjunctiva. The present invention is especially concerned with the treatment of blepharitis and blepharoconjunctivitis particularly associated with ocular rosacea.
Background Of The Invention
Blepharitis is an inflammation of the eyelids. Blepharoconjunctivitis is an inflammation of the eyelids and the conjunctiva of the eye. Both conditions are associated with the condition known as ocular rosacea.
Rosacea is a disease of the skin (acne rosacea) and eyes (ocular rosacea) of unknown etiology and a variety of manifestations. The clinical and pathological features of the eye disease are nonspecific, and the disease is widely underdiagnosed by ophthalmologists.
More specifically with respect to ocular rosacea, ocular rosacea may involve the eyelids, conjunctiva, and cornea. Common manifestations of ocular rosacea include blepharitis, blepharoconjunctivitis, meibomianitis, chalazia, styes and conjunctival hyperemia.
References which discuss ocular rosacea include: "Ocular Rosacea" by M. S. Jenkins et al, American Journal of Opthalmology, Vol. 88:618-622 (1979); "Blepharitis Associated With Acne Rosacea and Seborrheic Dermatitis" by J. P. McCulley et al, in Oculocutaneous Diseases, edited by J. P. Callen et al, Little, Brown & Company, International Ophthalmology Clinics, Spring 1985, Vol, 25, No. 1, pp. 159-172; and "Ocular Rosacea" by D. J. Browning et al, Survey of Ophthalmology, Vol. 31, No. 3, November-December 1986, pp. 145-158.
In the article by McCulley et al mentioned above, on pages 170-172, several treatments for blepharitis are disclosed. These treatments include: topical antibiotics; oral tetracycline; SSA neutralizers; exoenzymatic inhibitors; vitamin A analogs; and other means of affecting meibomian gland secretions.
In another prior art reference, Textbook of Dermatology, 4th Edition, A. Rook et al editors, Vol. 2, p. 2152, there is a disclosure that Demodectic blepharitis may be treated with bathing with boric acid or with benzalkonium.
In the article by Browning et al mentioned above, on p. 155, there is a disclosure that for treatment of ocular rosacea only tetracycline has been critically studied. In the same article, there is mentioned that metronidazole has been used for treatment of skin lesions of rosacea. However, the article does not teach the use of a nitromidazole compound (including metronidazole) with a suitable carrier for topical treatment of ocular tissues.
In another reference, namely "Topical Metronidazole Therapy For Rosacea", by P. A. Bleicher et al, Arch Dermatol., Vol. 123, May 1987, pp. 609-614, there is a disclosure that metronidazole can be used in a gel for treatment of rosacea of the skin. However, there is no disclosure that metronidazole can be used for ocular rosacea.
The prior art also teaches other treatments for eye inflammations using the direct application of a treating composition to the eye. For example, in U.S. Pat. No. 4,612,193 to Gordon et al, there is a disclosure that a blepharitic infection (not characterized as being caused by ocular rosacea) can cause a stye and that an ointment is provided to treat the stye. The ointment is based on yellow mercuric oxide, boric acid, and wheat germ oil.
In the book Diseases of the Cornea, 2nd Edition, by M. G. Grayson, C. Z. Mosby Company, 1983, pp. 119-209, there is a disclosure that blepharitis can be treated using antibiotic ointments containing antibiotics such as bacitracin, erythromycin, chloramphenicol, and tetracycline. Other active agents for treating blepharitis include Rifampin, a very dilute steroid such as 0.12%, prednisolone, and polysulfide.
The prior art treatments for eye inflammations have several disadvantages. For example, when tetracycline is taken orally it takes between two to three months to have a significant effect. Furthermore, tetracycline is plagued with side effects such as super infections, light sensitivity, cramp feelings of the user, contra-indication if the user is pregnant, and resultant feelings that are similar to those when a person has the flu. Therefore, it would be desirable to avoid the use of tetracycline for the treatment of eye inflammations (e.g. ocular rosacea and related conditions).
Another eye condition is known as dry eye which results from an abnormal difficiency of tear production. A discussion of dry eye is found in the article entitled "Tear Physiology and Dry Eyes" by F. J. Holly et al, Survey of Ophthalmology, Vol. 22, No. 2, September-October 1977, pp. 69-87. As disclosed in the Holly et al article, the primary treatment for dry eye is the use of artificial tears applied topically. Unfortunately, blepharitis is often misdiagnosed as dry eye. As a result, treatment with artificial tears is inadequate to cure the patient's problem. It would be desirable to provide a pharmaceutical composition that would treat the actual blepharitis in the instance where the condition was misdiagnosed as dry eye.
Another problem that has received attention in the ophthalmological literature lately is infection by a parasite known as Acanthamoeba hystolytica which particularly plagues users of contact lenses. A particularly devastating infection results from this parasite leaving the victim particularly susceptible to blindness in an infected eye. A presently used treatment for Acanthamoeba is a therapeutic agent known as brolene which is an over-the-counter British stye medication. Other known treatments for Acanthamoeba include antibiotics such as micadasol and mediasforan. However, it would be desirable if another nonantibiotic agent could be applied topically to alleviate the deleterious conditions caused by the Acanthamoeban organism.
Another problem associated with wearers of contact lenses is the formation of lumps under the lenses. Lumpy deposits formed under the contact lenses are very often due to undiagnosed blepharitis. By alleviating the underlying blepharitis condition, the cause of lump formation under contact lenses could be alleviated or removed. In this respect, it would be desirable to provide a treatment to prevent lump formation under contact lenses that result from undiagnosed blepharitis.
Although systemic treatments for eye conditions are known, such treatments are not popular with ophthalmologists. An eye doctor generally prefers to prescribe an eye medicine that is administered topically to the eye rather than prescribe a pill or the like which administers the medicine systemically. Therefore, it would be desirable to provide a treatment for blepharitis, or blepharoconjunctivitis, or ocular rosacea generally that is administered in a form such as a topically applied ointment or topically applied drops.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to alleviate the disadvantages and deficiencies of the prior art by providing a treatment for blepharitis, blepharoconjunctivitis, and ocular rosacea that is administered in the form of eye drops or other topically administered eye preparations.
Another object of the invention is to provide a treatment that avoids the use of tetracycline or other antibiotics for treating ocular inflammations such as ocular rosacea and related conditions.
Another object of the invention is to provide a pharmaceutical composition that treats actual blepharitis in an instance where the actual condition is misdiagnosed as dry eye.
Still another object of the invention is to provide a topical treatment for the eye conditions resulting from infection by Acanthamoeba hystolytica.
Yet another object of the invention is to provide a treatment to prevent lump formation under contact lenses that result from undiagnosed blepharitis.
In accordance with the teachings of the present invention, a pharmaceutical composition is provided for treating blepharitis and blepharoconjunctivitis generally and especially associated with ocular rosacea. The pharmaceutical composition of the invention includes an amount of a nitroimidazole compound effective for treating the blepharitis and/or blepharoconjunctivitis and/or ocular rosacea; and a carrier for the nitroimidazole compound wherein the carrier is suitable for direct application to the eye tissues. The nitroimidazole compound is selected from the group consisting of metronidazole, nimorazole, tinidazole, ordinidazole, secnidazole, and carnidazole. The preferred compound is metronidazole.
The carrier may be in the form of an ointment, e.g. petrolatum-based or a water soluble gel, or in the form of a liquid to be applied to the eye in the form of eye drops.
The preferred carrier for eye drops is an artificial tear composition including primarily isotonic sodium chloride. In addition, a cellulose ether such as methylcellulose may be added to the artificial tear carrier. Other cellulose ethers such as hydroxypropylmethylcellulose and hydroxyethylcellulose may be included in the artificial tear carrier. The artificial tear composition may also include a polyvinyl alcohol.
The composition of the invention is applied to ocular tissues directly for treating the conditions of blepharitis, blepharoconjunctivitis, and ocular rosacea.
These and other objects and advantages of the present invention will become apparent from a reading of the following specification.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Here are represented several formulations for pharmaceutical compositions of the invention.
EXAMPLE 1
One gram of metronidazole is added to 1,000 grams of artificial tear carrier with stirring. The artificial tear carrier is isotonic sodium chloride solution. This formulation provides an approximately 0.1% solution of metronidazole in artificial tear carrier for application to the patient by means of eye drops.
EXAMPLE 2
7.5 grams of metronidazole are added to 992.5 grams of artificial tear solution with stirring to provide a formulation containing approximately 0.75% metronidazole in an artificial tear carrier.
EXAMPLE 3
10 grams of metronidazole are added to 990.0 grams of isotonic sodium chloride solution with stirring to provide a 1% metronidazole solution in isotonic sodium chloride carrier.
EXAMPLE 4
An eye drop formulation is made up by blending the following: 10 grams metronidazole, 10 grams methylcellulose, and 980 grams isotonic sodium chloride. This formulation contains approximately 1% metronidazole, 1% methylcellulose, and the balance being isotonic sodium chloride carrier.
EXAMPLE 5
Another eye drop formulation is made up by blending the following: 10 grams metronidazole, 14 grams polyvinyl alcohol, and 976 grams isotonic sodium chloride artificial tear solution. The resulting formulation contains approximately 1% metronidazole, 1.4% polyvinyl alcohol, and the balance being artificial tear carrier.
EXAMPLE 6
Another eye drop formulation is made by blending the following: 15 grams metronidazole and 985 grams of isotonic sodium chloride artificial tear solution with stirring to provide a 1.5% metronidazole solution.
EXAMPLE 7
Another eye drop formulation is made by stirring 20 grams metronidazole into 980 grams of artificial tear solution to provide a 2.0% metronidazole solution.
EXAMPLE 8
The following ointment can be prepared by blending 10 grams of metronidazole thoroughly with 990 grams petrolatum vehicle (an ointment base) to provide an ointment suitable for application to the ocular tissues which contains 1% metronidazole.
EXAMPLE 9
The following ointment can be prepared by blending 15 grams of metronidazole thoroughly with 985 grams petrolatum vehicle (an ointment base) to provide an ointment suitable for application to the ocular tissues which contain 1.5% metronidazole.
EXAMPLE 10
The following ointment can be prepared by blending 20 grams of metronidazole thoroughly with 980 grams petrolatum vehicle (an ointment base) to provide an ointment suitable for application to the ocular tissues which contains 2% metronidazole.
By employing the principles of the invention, numerous objects are realized and numerous benefits are obtained. For example, a pharmaceutical composition is provided to treat blepharitis, blepharcoconjunctivitis, and ocular rosacea and is administered in the form of an ointment or in the form of eye drops. The method of treatment of the invention avoids the use of tetracycline for treating ocular rosacea and related conditions. With the invention, a pharmaceutical composition is provided that treats actual blepharitis in the case where the condition is misdiaqnosed as dry eye. The invention provides a topical treatment for eye conditions resulting from infection by Acanthamoeba hystolytica. The invention provides a treatment to prevent lump formation under contact lenses that result from blepharitis.
Obviously, many modifications may be made without departing from the basic spirit of the present invention. Accordingly, it will be appreciated by those skilled in the art that within the scope of the appended claims, the invention may be practiced other than has been specifically described herein. | A method and composition for treating blepharitis or blepharoconjunctivitis comprises topical administration of a nitroimidazole compound, e.g. metronidazole in a suitable carrier directly to affected ocular tissues. The carrier can be an artificial tear solution or an ointment or water soluble gel base. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to (1) U.S. Provisional Patent Application Ser. No. 61/587,802, filed Jan. 18, 2012, entitled “Display Mechanism for Communicating Transport Vehicle Related Ground Deceleration Alerts to the Operators of an Aircraft or Vehicle for the Purposes of Failure Sensitive Mitigation Actions,” and (2) U.S. Provisional Patent Application No. 61/679,879, filed Aug. 6, 2012, entitled “Vehicle Operator Display and Assistive Mechanisms,” the entire contents of both of which are incorporated herein by this reference.
FIELD OF THE INVENTION
[0002] This invention relates to systems and methods for providing information to (at least) vehicle operators and more particularly, but not necessarily exclusively, to mechanisms and techniques for supplying human pilots with information in manners designed to assist the pilots in coping with probable degradation of ground deceleration performance of their associated vehicles.
BACKGROUND OF THE INVENTION
[0003] Commonly-owned U.S. Pat. No. 8,224,507 to Edwards, et al. (the “Edwards patent”), whose contents are incorporated herein in their entirety by this reference, identifies rationales for improving information available to pilots of, for example, soon-to-land aircraft as to conditions likely to be encountered upon landing. Arguably the most famous recent circumstance in which lives were lost because of inadequate information about landing conditions delivered to a flight crew is the crash of Southwest Airlines Flight No. 1248 on Dec. 8, 2005, which flight departed the end of a runway and left the airfield boundary at Midway International Airport in Chicago, Ill. Quoting the USA Today newspaper, the Edwards patent states:
[0004] . . . the pilots “assumed the runway was in ‘fair’ condition, based on reports from other pilots radioed to them by air traffic controllers.” However, subsequent analysis of objective data “show[ed] the conditions were ‘poor’ at best,” with the runway “so slippery that it would have been difficult for people to walk on, providing minimal traction for the jet's tires as pilots tried to slow down.”
[0000] See Edwards patent, col. 2, 11. 22-29.
[0005] The reason the pilots reporting those “fair” conditions had no manner of discerning their actual brake system performance was because the information about those systems was not designed to be measured, nor was it designed to be delivered to the flight crews. It is essentially impossible for pilots to discriminate between the aerodynamic forces acting upon an aircraft and the ground-based braking forces during a landing. As a result, the risks associated with poor ground-based braking system performance are not visible to a pilot in the act of directing his aircraft during such a maneuver.
[0006] Accordingly, detailed in the Edwards patent are systems and methods of improving or increasing (or both) the information available to operators in these and other circumstances. In some systems disclosed in the Edwards patent, objective information relating to performance of one aircraft using a runway is transmitted to an aircraft scheduled next or soon to use the runway for evaluation by the operator of that aircraft. Among many advantages of these systems are that they provide more objective information than conventional reports (which may consist of as little as a qualitative assessment of “good,” “fair,” or “poor”), the information may be provided in real-time (or near real-time), and the information may be generated without closing a runway to conduct conventional mechanical, ground-based friction testing.
[0007] Certain systems of the Edwards patent contemplate providing a vehicle operator with information relating to both (A) brake pressure commanded by an operator of an aircraft upon landing on a runway and (B) brake pressure delivered to the brakes of the aircraft after anti-skid control computer calculations are performed on-board that aircraft. Although other information may be provided additionally or alternatively, recently-obtained commanded and delivered brake pressure information may be especially valuable to operators of soon-to-land aircraft, as the information relates directly to what the operators will imminently experience. It thus may differ from the information most desired by engineers or regulatory authorities, for example, tasked with after-the-fact evaluation of runway conditions or an engineering analysis of aircraft performance.
[0008] Indeed, while humans are not considered “machines,” they do operate under industry recognized cognitive limitations when in the process of interacting with mechanical devices. This relationship between the performance of a human and how that affects the performance of a machine is known as the field of “human factors” study. Recognizing human limitations and creating communication paths between vehicle and operator likely to overcome the limitations is thus a useful and significant goal.
[0009] As suggested by the accident at Midway Airport (among other events), unexpected degradation in ground-based deceleration systems can drastically erode safety and lead to catastrophic consequences any time a vehicle is decelerating on a surface while employing both aerodynamic and ground-based deceleration systems. For a landing aircraft, the operator must employ muscle memory techniques for engaging ailerons, rudder, elevator, and throttle while simultaneously directing his vision to the designated operating runway. While travelling down the surface of a runway and in controlling both lateral movement and longitudinal movement of the aircraft, the pilot or operator currently has no automated method of alert (other than his own qualitative “feeling”) to queue an alternate sequence of actions should degraded system performance make such a decision advisable.
[0010] More specifically, a human operator of a decelerating aircraft must simultaneously control three dimensions of movement. In addition to controlling lateral and longitudinal movement of the aircraft, prior to contact with the ground he must align the flight path of the vehicle with the orientation of the surface on which he is to decelerate. This act requires the use of both feet and both hands to operate the rudder, ailerons, elevator, and throttle(s) of the aircraft. Meanwhile, the pilot's vision must be focused outside so that a continuous and speedy feedback loop develops between his visual cues and the actions of his hands and feet.
[0011] All landings involving human manipulation of controls are “visual” landings even though automation and navigational instruments may have delivered a craft to a position where such an event can take place. To this degree all such events require an operator of a craft to utilize a field of view designed specifically for viewing the environment outside the cabin or cockpit of the vehicle. However, the human mind is limited in its ability to process concurrent information at a conscious level of awareness. Attention is the cognitive mechanism in which an individual selects and processes important information while filtering and ignoring irrelevant information. Many factors can affect attention ranging from the physiological effects of stress to recognized cognitive limitations of the human brain. The concept of the “attentional blink,” for instance, represents the inability to identify the second of two targets when the two are presented in close temporal succession or rapid sequence. This represents a long-lasting attentional deficit that is due to the length of time an identified object occupies attentional capacity, or remains in the person's awareness. In this case, this attentional deficit can mask important real-time deceleration system performance since current aircraft are not designed to display alerts or warnings of this nature in the visual field of view used for landing. Studies have documented, however, that perceptual, spatial and temporal cues have been found to be effective in manipulating attention during periods in which attentional blink is most likely to exist. This is but one example of a range of human factors issues that can create barriers to the effective human integration with aircraft systems designed to produce a ground deceleration during the landing maneuver.
[0012] The science of procedural memory teaches that the cognitive limitations of a pilot will not allow him to perform more than one analytical function at a time. Functions that require more than one action are employed using muscle memory as developed through repetition and training. Procedural memory is memory for how to do something. It usually resides just below a person's conscious awareness and guides the processes humans perform such as when tying shoes, riding a bicycle, or landing an airplane. Procedural memories are used without the need for conscious control or attention. For a pilot landing an airplane, the continuous analysis of where the direction his flight and ground path take him becomes his sole focus. In the study of human factors he is said to be “task saturated” because the task of controlling the flight path of the vehicle maximizes his abilities of perception and analysis at a certain level of awareness. He therefore must rely on procedural skill to accomplish any other demands he may encounter.
[0013] To acquire a procedural skill, one must pass through three phases. The first is the “cognitive” phase, which is when attention is most significant. It is the time when a person organizes and understands how parts come together as a whole. The second phase is the “associative” phase, which involves repeating the practice until patterns emerge and the skill is learned. Important stimuli are incorporated and irrelevant information is dropped, so the ability to differentiate the two is important for perfecting the skill. The third phase is the “autonomous” phase, which involves perfecting the skill so that it seems automatic. The ability to discriminate important from irrelevant information is quicker, more accurate, and requires less thought process.
[0014] The landing environment, in which a pilot is focused on using visual cues to operate the aircraft systems, relies entirely on this autonomous phase of memory. Without a cue, or signal, to do things differently due to deteriorating conditions, a pilot or operator will continue with procedural memory despite an unfavorable outcome. By contrast, a cue could provide a signal to alert and redirect the pilot's attention to implement a different set of procedural memories.
[0015] Furthermore, decisions concerning what actions are appropriate (“go around” or “continue,” for example) are analyzed prior to the event so the operator need only be alerted to an expected cue to make an immediate assessment of his actions and continued techniques. This environment is classified as a “task saturated” one because there are so many actions taking place that there is very little room to employ a human function that relies upon anything but the simplest of cognitive alerts. This is an area where the possibility of errors due to perception and technique are greatly increased and where integration of man to machine is most important. It is also the state in which a pilot's vision is entirely dedicated outside the aircraft, away from his cockpit instruments.
[0016] Eye direction normally coincides with attention; however, research regarding the human detection of signals indicates that the mind processes more information peripherally than thought possible. As attention is directed across a person's field of vision (centrally and peripherally), items falling within what is referred to as the “attention spotlight” will be preferentially received, regardless of eye direction. In other words, humans can attend to something without looking directly at it, as long as it lies within the field of view being utilized.
[0017] Human visual cognition is particularly acute when a changing light source occurs within the peripheral vision of the operator. That changing light source can be either a flashing color or an alternating color(s), for example, and may (but need not necessarily) incorporate an alternating “wig wag” alert using one color or alternating two colors in the same display. Since the field of view of the pilot or operator is limited to the forward visibility above the instrument glare shield during a ground deceleration maneuver, placing a cueing or alerting device in this area would beneficially capture the operator's peripheral vision. Alternatively or additionally, including an aural alert may be advantageous.
[0018] Research performed regarding high task-loaded environments such as this indicates that the response to an alert must by necessity be a binary one, meaning that an alternate technique constituting a pre-learned muscle memory sequence is the only plausible consequence of an alert occurring during this phase of operation. Such a muscle memory response would include the necessary manipulation of the controls required to properly configure the vehicle for maximum effective deceleration and control.
[0019] Finally, the concept of “safety” is in effect the state in which exposure to risk is reduced to an acceptable level. “Risk” may be defined as the likelihood that a hazard relating to ground deceleration will result in an unwanted outcome that may produce harm to property, people, or both property and people. To have a “safe” system it is necessary to articulate the details that make up any given hazard. For the purposes of an aircraft decelerating on the surface, these hazards may include (but are not limited to) a difference between commanded and delivered wheel brake forces as the result of the actions of an anti-skid system (as noted above), the failure of a spoiler system to apply downward forces to a wheel brake system, degraded or absence of thrust reverser forces, a braking performance significantly different than selected by an automatic braking system, a failure of a pneumatic tire, the failure of a braking force delivery system such as hydraulics, or a tire to ground interaction for which an anti-skid system significantly reduces delivered braking forces. When these hazards occur during the time when a vehicle is travelling on a surface for the purpose of decelerating, the pilot flying currently has no indication of the hazards within the field of view he must use to control his vehicle while utilizing the muscle memory techniques as described above. The issue is sufficiently acute in connection with unrecognized deactivation of speedbrakes on aircraft that the National Transportation Safety Board recently recommended that warning horns be installed on jetliners to alert pilots if the speedbrakes cease functioning.
SUMMARY OF THE INVENTION
[0020] The present invention provides assistive mechanisms designed to reduce risks associated with degraded landing and other situations. Some versions of the invention include a display unit with a visual indicator located above the glare shield or dashboard of a cockpit, cabin, or other area located within the normal field of view of the operator. The invention also may include a distinctive aural alert designed to be easily distinguished from other aural alerts the vehicle may employ for other purposes. A function of these alerts is to take the measurements supplied from non-theoretical and direct ground-deceleration system components (such as not but limited to those discussed in the Edwards patent) and provide an indication of system function that has been determined to be less than a predetermined level of desirability. The alerts will then enable the operator to capture human and mechanical based degradations and employ an operational technique to mitigate the hazards produced by such degradation in system function.
[0021] Various embodiments of an alerting device may include a display unit with a visual indicator comprising multiple pixels. The device also may include a mounting post and a glare shield if desired or appropriate. Individual pixels, or contiguous sets of pixels, preferably are colored red and amber alternately, although other colors may be employed instead. Red and amber are preferred colors at least in part because they are used in human-factors designs of cockpits, with amber representing a cautionary alert and red representing an emergency. The indicator may be configured to allow for, e.g., (1) flashing amber pixels, (2) flashing red pixels, (3) flashing amber and red pixels, (4) steady (non-flashing) illumination of amber pixels, and (5) steady (non-flashing) illumination of red pixels. Alternatively or additionally, the indicator may define letters, words, or symbols or flash colors alternately on different portions of the device. The configuration may be a separate indicator, incorporated as an alert displayed on a heads-up navigation device, or mounted to a windshield pillar, for example. Light intensities may vary for day or night conditions, for example, or otherwise as suitable. Similarly, flashing frequencies may vary. Information conveyed by the device to a vehicle operator may assist the operator in mitigating hazards.
[0022] It thus is an optional, non-exclusive object of the present invention to provide systems and methods for providing information to (at least) vehicle operators.
[0023] It is another optional, non-exclusive object of the present invention to provide mechanisms and techniques for supplying human pilots with information in manners designed to assist the pilots in coping with probable degradation of ground deceleration performance of their associated vehicles.
[0024] It is also an optional, non-exclusive object of the present invention to provide display units with visual indicators designed to illuminate in the normal peripheral fields of view of the pilots.
[0025] It is a further optional, non-exclusive object of the present invention to provide aural alerts to pilots.
[0026] It is, moreover, an optional, non-exclusive object of the present invention to provide colored cues to vehicle operators, with different colors signifying different levels of required action.
[0027] It is an additional optional, non-exclusive object of the present invention to provide display indicators in which individual or sets of red and amber pixels may flash or be illuminated steadily depending on actual or anticipated conditions.
[0028] It is another optional, non-exclusive object of the present invention to provide an option for an alert as described above to signal an automatic flight control response designed to mitigate the landing risk such as, but not limited to, automatic employment of maximum wheel brake effort, ground spoilers, or thrust reverse.
[0029] Other objects, features, and advantages of the present invention will be apparent to those appropriately skilled in the art with reference to the remaining text and drawings of this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 is a simplified, operator's-eye view of a runway or similar surface along which a vehicle may travel together with exemplary alerting devices.
[0031] FIG. 2 is a front view of an alerting device of FIG. 1 .
[0032] FIG. 3 is a side view of the alerting device of FIG. 2 .
[0033] FIG. 4 is a flow diagram identifying exemplary conditions affecting presentation of information by the alerting device(s) of FIGS. 1-3 .
[0034] FIGS. 5A-B are exemplary visual indicators that may form part of an alerting device of FIGS. 1-3 .
DETAILED DESCRIPTION
[0035] Depicted in FIG. 1 is a portion of a cockpit C of an exemplary aircraft A. Visible in FIG. 1 within cockpit C are windows 10 A-D, panels of instruments 14 A-B, main glare shield 16 , and one or more alerting devices 18 (see also FIGS. 2-3 ). Also visible in FIG. 1 outside cockpit C are runway R and horizon H. Although FIG. 1 relates to an aircraft A, it alternatively could show portions of a car, truck, bus, or other ground-based vehicle approaching, for example, a roadway or a boat approaching an area of water.
[0036] As illustrated in FIG. 1 , the field of view of a pilot (whether seated to the left or right of the center of cockpit C) of aircraft A includes forward-looking windows 10 B-C for visual acquisition of the runway R. Windows 10 B-C are the primary visual source for information relating to the operational control of the aircraft A while it is in the process of decelerating. Accordingly, at least one of alerting devices 18 A-B preferably is located within the pilot's field of view, above glare shield 16 , and so as to display information at a level approximating that of the pilot's eyes. If two such alerting devices 18 A-B are present, one ( 18 A) beneficially may be positioned to the left of the center of cockpit C for use primarily by an operator seated to the left of center, while the other ( 18 B) may be positioned to the right of the center of cockpit C for use primarily by an operator seated to the right of center. One or more devices 18 alternatively or additionally may be mounted to or incorporated into windshield pillar P (see, e.g., devices 18 C-D) or incorporated into a heads-up display D.
[0037] FIGS. 2-3 show aspects of an exemplary alerting device 18 . Device 18 may include a visual indication or display 22 , optional mounting post 26 , a housing 30 , and a glare shield 34 . Display 22 preferably comprises multiple pixels, while post 26 (if present) desirably is sufficiently long to position device 18 in the pilot's field of view above main glare shield 16 .
[0038] Detailed in FIG. 4 are examples of flow paths of information that may be gathered, generated, obtained, or calculated for device 18 . Consistent with aspects of the Edwards patent, performance of the wheel brake system of aircraft A may be defined by the relationship between the two forces designated F 1 and F 2 in FIG. 4 , with F 1 relating to braking force commanded by the pilot and F 2 relating to braking force delivered following operations of an aircraft anti-skid controller. If the difference between F 1 and F 2 exceeds a preset threshold, for example, a real-time state of degraded braking system performance exists. Existence of degraded system performance in turn suggests alternate techniques may be required by the aircraft operator to mitigate risks such a state represents, causing alert activity on display 22 and on optional aural warning generator 38 . Existence of the degraded performance also may, if desired, be recorded for subsequent analysis and transmitted to operators of other craft or elsewhere for receipt, processing, and displaying to those operators.
[0039] FIG. 4 also depicts other examples of information that could result in alert activity on display 22 . Any or all of the information may be input to control unit 42 (which may be integral with or separate from device 18 ) for assessment together with information confirming aircraft A has achieved weight on wheels (WOW) since having become airborne or is in the process of decelerating once acceleration has occurred (such as with a rejected takeoff, for example). This information may arrive via a data stream utilizing the flight data acquisition unit of aircraft A as used to deliver information to the flight data recorder and or quick access recorder if the aircraft A is so equipped.
[0040] Control unit 42 also may accept input from vehicle operators, cockpit equipment, or otherwise. As an example, at times an aircraft may be considered airworthy notwithstanding inoperative thrust reversers or autobrakes. This inoperability thus may be identified to control unit 42 , so no monitoring of the known inoperative equipment need occur.
[0041] FIG. 5A illustrates a preferred manner of presenting information on display 22 . Although display 22 is shown as comprising a 6×6 set of pixels, it is not restricted to that arrangement and may include more or fewer such pixels. Advantageously, display 22 may comprise sets of alternating red and amber pixels, producing a checkerboard pattern as shown in FIG. 5A . In this case amber pixels may represent cautionary situations, while red pixels may represent emergency situations in which timely pilot response is required.
[0042] Display 22 preferably is designed to provide at least (1) flashing amber pixels, (2) flashing red pixels, (3) alternating flashing amber and red pixels, (4) steady illumination of amber pixels, and (5) steady illumination of red pixels. Illumination may be provided in any suitable manner, including (but not limited to) light-emitting diodes (LEDs), fiber optics, or other light sources. Intensity of the pixels may be set differently for day and night operations in coordination with a selection signal generated by the operator for the general instrument panel that is common to most aircraft.
[0043] Depicted in FIG. 5B is an alternate display 22 whose pixels are utilized to define letters, words, symbols, etc. In the example of FIG. 5B , the letters “SPLR” are shown, representing the word “SPOILER.” In this case display 22 may be alerting an operator to failure or performance degradation of one or more spoilers of the vehicle being operated.
[0044] The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Further modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention. | Detailed are assistive mechanisms for vehicle operators designed to reduce risks associated with degraded landing and other situations. Some mechanisms may include a display with a visual indicator located within the peripheral field of view of an operator. Aural alerts may also be employed. Information suggesting degradation of, for example, ground deceleration performance may alert the operator to perform unusual or abnormal actions to mitigate hazards produced by the performance degradation. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image pickup element or a mounting device therefor, for use in an image pickup apparatus such as a video camera or a digital camera.
2. Related Background Art
FIG. 1 is a vertical cross-sectional view schematically showing the configuration of an image pickup device, employing a solid-state image pickup element contained in a conventional discrete package.
In FIG. 1 there are shown a package 1 for the solid-state image pickup element; an image pickup optical lens system 2 ; and a position defining member 3 for defining the position of the package 1 for the solid-state image pickup element relative to the image pickup optical system 2 .
The relative position of the package 1 of the solid-state image pickup element and the position defining member 3 along a plane perpendicular to the optical axis is defined by an unrepresented positioning jig. Also the relative position of the package 1 and the position defining member 3 along the optical axis is fixed by adhesion, with the impingement of the position defining member 3 on the rear face, constituting a reference plane, of the package 1 . Electrode portions 4 of the package 1 pass through apertures 5 provided in the position defining member 3 and are inserted into holes 7 formed on a printed circuit board 6 positioned at the rear side of the position defining member 3 , and are fixed at the rear face of the printed circuit board 6 by soldering 8 to rands formed on the rear face thereof. Also the position defining member 3 , on which the solid-state image pickup package 1 is fixed, impinges on the image pickup optical system 2 for defining the position of the solid-state image pickup element 9 in the axial direction relative to the image pickup optical system 2 , and positioning holes 10 provided on the position defining member 3 engage with positioning projections 11 correspondingly provided on the image pickup optical system 2 for defining the position of the solid-state image pickup element 9 relative to the image pickup optical system 2 along the plane perpendicular to the optical axis. In this configuration, a shield case 12 is mounted on the printed circuit board 6 , so as to cover the electrode portions 4 of the solid-state image pickup package 1 fixed by solderings 8 to the rear face of the printed circuit board 6 .
FIG. 2 is a vertical cross-sectional view, schematically showing another configuration of an image pickup device, in which the package containing the above-mentioned solid-state image pickup element is so modified that the electrode portions 4 are bent. In FIG. 2, the same portions as those in FIG. 1 are represented by the same numbers as in FIG. 1 .
Referring to FIG. 2, the relative position between the solid-state image pickup package 1 and the position defining member 3 along the plane perpendicular to the optical axis is defined by an unrepresented positioning jig, while the relative position in the axial direction is fixed by adhesion, upon impingement of the position defining member 3 on the reference rear face of the solid-state image pickup package 1 . The electrode portions 4 of the package 1 pass through the apertures 5 provided in the position defining member 3 and are fixed at the rear face of the printed circuit board 6 , positioned at the rear side of the position defining member 3 , by soldering 8 to rands formed on the front surface of the printed circuit board 6 . Also the position defining member 3 , on which the solid-state image pickup package 1 is fixed, impinges on the image pickup optical system 2 for defining the position of the solid-state image pickup element 9 in the axial direction relative to the image pickup optical system 2 , and positioning holes 10 provided on the position defining member 3 engage with positioning projections 11 correspondingly provided on the image pickup optical system 2 for defining the position of the solid-state image pickup element 9 relative to the image pickup optical system 2 along the plane perpendicular to the optical axis.
In the conventional configuration shown in FIG. 1, however, since the electrode portions 4 are fixed by solderings 8 to the rear surface of the printed circuit board 6 , such soldered portions 8 protrude on the rear side thereof and constitute a dead space against the compactization of the equipment. Also the solid-state image pickup element 9 is very susceptible to the influence of noises, but a shield case 12 , if provided for avoiding such influence, increases the total thickness, hindering also the compactization of the equipment.
On the other hand, in the above-described configuration shown in FIG. 2, in which the electrode portions 4 of the package 1 containing the solid-state image pickup element 9 are bent in L-shape, the soldered portions 8 of the electrode portions 4 are present on the front surface of the printed circuit board 6 and do not protrude to the rear surface thereof, thus eliminating the dead space on the rear surface of the printed circuit board 6 as in the configuration shown in FIG. 1 . Also on a surface of the printed circuit board 6 , opposite to the surface electrically connected to the solid-state image pickup package 1 , there is provided a ground pattern substantially covering the printed circuit board 6 to obtain the shield effect, thereby dispensing with the shield case which is a factor increasing the total thickness in the configuration shown in FIG. 2 .
In the configuration shown in FIG. 2, however, in forming the electrode portions 4 into L shape, such portions have to be chucked and a chucking area for this operation has to be secured, so that the gap from the mounting face of the position defining member 3 for the solid-state image pickup package 1 to the bent position of the electrode portions 4 cannot be made small. For this reason, the distance L from the solid-state image pickup package 1 to the printed circuit board 6 has a certain lower limit, thus hindering the reduction in the total thickness. Furthermore, the length from the rear face of the solid-state image pickup package 1 to the bent position of the electrode portions 4 tends to fluctuate considerably. Also, cracking tends to appear in the forming operation if the electrode portions are chucked incompletely. Furthermore, the image pickup element may be damaged by the electromotive force generated at the forming operation.
SUMMARY OF THE INVENTION
The present invention is to resolve the drawbacks mentioned in the foregoing, and a first object thereof is to provide a surface mountable image pickup device of a thin structure for mounting.
A second object of the present invention is to provide an image pickup device and a leadless electric component mounting device, capable of reducing the total thickness of the image pickup device.
A third object of the present invention is to provide an image pickup device and a leadless electric component mounting device, capable of providing a shield effect without utilizing the shield case which is a factor for increasing the total thickness.
The above-mentioned first object can be attained, according to a preferred embodiment of the present invention, by a surface mountable leadless image pickup element in which a light receiving face is formed on the upper face in a flat package, the lower face of the package is used as a position defining face in the axial direction, and plural electrodes for soldering are formed in at least mutually opposed pair of lateral faces, among the four lateral faces, of the flat package.
Also the above-mentioned second object can be attained, according to a preferred embodiment of the present invention, by an image pickup device comprising an optical system for picking up the image of an object, photoelectric conversion means for photoelectric conversion of the object image picked up by the optical system, electric signal output means for outputting electric signals from the photoelectric conversion means, and position defining means for defining the relative position of the optical system and the photoelectric conversion means, wherein the electric signal output means is positioned between the photoelectric conversion means and the position defining means.
Also the above-mentioned third object can be attained, according to a preferred embodiment of the present invention, by a leadless electric component mounting device for mounting a leadless electric component in a mounting position in the device, comprising a position defining member for mounting the leadless electric component in a part with a predetermined gap and positioning the leadless electric component in the mounting position, and a printed circuit board electrically connected to the electrodes of the leadless electric component and derived through the above-mentioned gap.
Still other objects of the present invention, and the features thereof, will become fully apparent from the following description, which is to be taken in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal cross-sectional view showing the configuration of a conventional image pickup device;
FIG. 2 is a longitudinal cross-sectional view showing the configuration of another conventional image pickup device;
FIG. 3 is an exploded perspective view showing the configuration of a first embodiment of the present invention;
FIG. 4 is a longitudinal cross-sectional view showing the configuration, in an assembled state, of an image pickup device constituting the first embodiment of the present invention;
FIG. 5 is a plan view, with the package of the solid-state image pickup element being removed, showing the configuration of the image pickup device of the first embodiment;
FIGS. 6A, 6 B and 6 C are views showing the configuration of a package for the solid-state image pickup element employed in the image pickup device of the first embodiment;
FIG. 7 is a plan view showing the configuration of a printed circuit board employed in the image pickup device constituting a second embodiment of the present invention;
FIG. 8 is a schematic view showing the mounting method for the solid-state image pickup element in a third embodiment of the present invention;
FIG. 9 is a plan view showing the relationship between the package for the solid-state image pickup element and the position defining member in the third embodiment;
FIG. 10 is a cross-sectional view of the package for the solid-state image pickup element in the third embodiment;
FIG. 11 is a view showing an example of the position defining method for the solid-state image pickup element relative to the position defining member in the third embodiment;
FIGS. 12 and 13 are views showing examples of the position defining method for the solid-state image pickup element relative to the position defining member in the embodiments of the present invention;
FIG. 14 is a view showing an example of the ground pattern in the embodiments of the present invention;
FIG. 15 is a view showing the shape of the board folded in a box shape in the embodiments of the present invention; and
FIG. 16 is a view showing an example of the ground pattern in the embodiments of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
At first there will be explained a first embodiment of the present invention with reference to FIGS. 3 to 5 and 6 A to 6 C, wherein FIG. 3 is an exploded perspective view showing the configuration of an image pickup device (leadless electric component mounting device) constituting a first embodiment of the present invention; FIG. 4 is a longitudinal cross-sectional view showing the configuration, in an assembled state, of an image pickup device constituting the first embodiment of the present invention; FIG. 5 is a plan view showing the configuration of the image pickup device of the first embodiment in the assembled state, wherein the image pickup optical system and the package of the solid-state image pickup element are removed; and FIGS. 6A to 6 C are respectively a plan view, a lateral view and a bottom view showing the configuration of the package for the solid-state image pickup element employed in the image pickup device of the first embodiment.
In FIGS. 3 to 5 and 6 A to 6 C, the same components as those in FIGS. 1 and 2 are represented by the same numbers as therein.
Referring to FIGS. 3 and 4, there are shown a package 1 for the solid-state image pickup element; an image pickup optical system 2 ; a position defining member 3 ; electrode portions 4 ; and a printed circuit board 6 .
The package 1 for the solid-state image pickup element is of a leadless chip carrier type having the electrode portions 4 at the end faces of the package as shown in FIGS. 6A to 6 C. The printed circuit board 6 is a flexible printed circuit board, provided with a pattern for outputting the signal from the solid-state image pickup element (leadless electric component) 9 and soldering rands for electrical connection therewith.
Referring to FIG. 3, after the electrode portions 4 of the solid-state image pickup package 1 are soldered to the rands formed on the printed circuit board 6 , the relative position of the package 1 and the position defining member 3 along the plane perpendicular to the optical axis is defined by an unrepresented positioning jig. Also the relative position of the package 1 and the position defining member 3 along the optical axis is defined by the impingement of the package 1 on plural projections 13 a to 13 d provided on the position defining member 3 , and the package 1 and the position defining member 3 are fixed by adhesion by introducing an adhesive material 15 into the gap therebetween through apertures 14 a, 14 b provided in the vicinity of the projections 13 a to 13 d.
Then the position defining member 3 , supporting the solid-state image pickup package 1 thereon, is made to impinge on the image pickup optical system 2 , thereby defining the axial position of the solid-state image pickup element 9 relative to the image pickup optical system 2 . In this state the positioning holes 10 provided on the position defining member 3 engage with the positioning projections 11 provided correspondingly on the image pickup optical system 2 to define the position of the solid-state image pickup element 9 relative to the optical system 2 along the plane perpendicular to the optical axis.
Since the projections 13 a to 13 d provided on the position defining member 3 have a height h satisfying a condition h≧t wherein t is the thickness of the printed circuit board 6 , the printed circuit board 6 can be positioned between the solid-state image pickup package 1 and the position defining member 3 .
Also as the apertures 14 a, 14 b formed on the position defining member 3 for introducing the adhesive material are positioned in the vicinity of the projections 13 a to 13 d of the position defining member 3 , the package 1 and the position defining member 3 are adhered in mutually contacting areas thereof and in the surrounding areas to attain a high adhesion strength. If the apertures 14 a, 14 b of the position defining member 3 are separated from the projections 13 a to 13 d, the adhesion between the package 1 and the position defining member 3 is to be made across the gap therebetween, so that there cannot be obtained a sufficient strength.
The printed circuit board 6 is so shaped as to substantially cover the rear face of the solid-state image pickup package 1 but so as to be absent in the portions where the projections 13 a to 13 d formed on the position defining member 3 are in contact with the package 1 and in the portions of the apertures 14 a, 14 b for introducing the adhesive material 15 , whereby the rear face of the solid-state image pickup package 1 is exposed in portions corresponding to the projections 13 a to 13 d and the apertures 14 a, 14 b and such exposed portions constitute adhering areas for the package 1 and the position defining member 3 .
The printed circuit board 6 is positioned between the solid-state image pickup package 1 and the position defining member 3 of the above-described configuration, and the package 1 is supported and fixed by the projections 13 a to 13 d formed on the position defining member 3 , so that the height h of the projections 13 a to 13 d can be extremely precisely determined at a value close to the thickness t of the printed circuit board 6 . It is therefore rendered possible to reduce the gaps of the package 1 , the position defining member 3 and the printed circuit board 6 , thereby reducing the entire thickness.
Also as the electrode portions 4 of the solid-state image pickup package 1 are electrically connected to a face, at the side of the package 1 , of the printed circuit board 6 , the electrode portions 4 of the package 1 and the soldered portions 8 do not protrude on the rear face of the printed circuit board 6 , whereby a dead space is not created on the rear face.
Furthermore, a shield effect can be obtained by forming a ground pattern substantially covering the printed circuit board 6 , on a face thereof opposite to the face where electrical connection is made with the electrode portions 4 of the package 1 .
In FIGS. 3 and 4 there are also shown bolt holes 16 a, 16 b, 16 c formed on the position defining member 3 , and bolts 17 a, 17 b, 17 c are inserted into these bolt holes 16 a to 16 c to fix the position defining member 3 to the image pickup optical system 2 .
In a second embodiment of the present invention shown in FIG. 7, a ground pattern is formed in an extended portion 6 a of the printed circuit board 6 , and, after the solid-state image pickup package 1 and the position defining member 3 are fixed by adhesion, the extended portion 6 a is folded back over the position defining member thereby completely covering the rear face of the package 1 and obtaining a higher shielding effect.
In the foregoing embodiments, the printed circuit board 6 is composed of a flexible printed circuit board, but it may also be composed of a hard board except in the second embodiment in which the extended portion 6 a is to be folded.
As explained in the foregoing, there is obtained an effect of reducing the entire thickness as the gaps of the electric signal output means, the photoelectric conversion means and the position defining means can be reduced.
Also there is obtained an advantage of obtaining the shield effect without employing the shield case which has been a factor of increasing the entire thickness.
In the following there will be explained a third embodiment of the present invention, providing a package for the solid-state image pickup element having a position defining face on the rear face of the package. More specifically there is disclosed a package for a solid-state image pickup element for use in an image pickup device, comprising an image pickup optical system, a solid-state image pickup package of a chip carrier type containing a solid-state image pickup element, a position defining member for defining the position of the solid-state image pickup package relative to the optical system, and a printed circuit board having rands for electrical connection with the solid-state image pickup element, wherein a step difference is formed, on the rear face thereof, between a mounting face for the position defining member and a face for electrical connection with the printed circuit board.
In such configuration, the step difference between the mounting face of the solid-state image pickup package for mounting the position defining member and the electrical connecting face with the printed circuit board can be selected close to the thickness of the position defining member, whereby the dimension of the package can be uniquely and precisely determined to eliminate the dead space.
FIG. 8 is a schematic view showing the mounting method of the solid-state image pickup element in the present embodiment, and FIG. 9 is a plan view of the solid-state image pickup package and the position defining member.
There are shown a solid-state image pickup package 101 ; a position defining member 102 ; a printed circuit board 103 ; an image pickup optical system 104 ; holes/projections 105 / 106 ; electrode portions 107 ; soldering portions 108 ; and a solid-state image pickup element (CCD) 109 .
The solid-state image pickup package 101 is of chip carrier type, and is provided, on the rear face thereof, with a step 120 having a difference of height L′ between a mounting face for the position defining member 102 and a face to be soldered to the printed circuit board 103 so as to satisfy a condition t′≦L′ wherein t′ is the thickness of the position defining member 102 .
As the solid-state image pickup package 101 is composed, as shown in a cross section in FIG. 10, by laminating ceramic wafers, there can be uniquely and precisely determined a mounting face 110 for the solid-state image pickup element, a mounting face 111 for the position defining member and an electrical connection face 112 to be soldered to the printed circuit board 103 .
The position defining member 102 defines the position of the solid-state image pickup element 109 in the axial direction by impingement on the mounting face 111 , for the position defining member, of the package 101 . Also the position of the package 101 relative to the position defining member 102 in the plane perpendicular to the optical axis is defined by the adhesion of the package 101 to the position defining member 102 , utilizing a positioning jig therefor.
In such configuration, the position of the solid-state image pickup element 109 in the plane perpendicular to the optical axis may be defined either, for example as shown in FIG. 11, by the engagement of holes 113 formed on the package 101 and corresponding projections 114 formed on the position defining member 102 , or, as shown in FIG. 12, by defining the position of the position defining member 102 by stepped portions 115 and lateral end faces thereof, formed on the solid-state image pickup package 101 .
In addition, in order to prevent the mounting of the solid-state image pickup package 101 in an opposite direction to the position defining member 102 , the package 101 is preferably provided, as shown in FIG. 13, with a stepped portion 116 for preventing such mounting in the opposite direction and the position defining member 102 is likewise provided with an extended portion 117 for preventing such mounting in the opposite direction.
The electrode portions 107 of the package 101 of which position is defined by the position defining member 102 are soldered, as explained in the foregoing, to the rands formed on the printed circuit board 103 at the side of the solid-state image pickup package 101 .
The position of the solid-state image pickup element 109 relative to the image pickup optical system 104 in the axial direction is defined by the impingement of the position defining member 102 on the pick up optical system 104 . Also the position of the solid-state image pickup element 109 relative to the image pickup optical system 104 in the direction of the plane perpendicular to the optical axis is defined by the engagement of the holes 105 formed on the position defining member 102 with the corresponding projections 106 formed on the image pickup optical system 104 .
The above-described configuration ensures the dimensional precision between the mounting face 110 of the solid-state image pickup element 109 and the mounting face 111 of the position defining member 102 . Also the dead space can be eliminated since the step difference, between the mounting face 111 , for the position defining member, of the package 101 and the face thereof for electrical connection with the printed circuit board 103 , is close to the thickness of the position defining member 102 . Furthermore, as the electrode portions of the solid-state image pickup package are electrically connected to the front face of the printed circuit board, there can be eliminated the dead space on the rear face of the printed circuit board, which has been a drawback in the conventional configuration.
Furthermore, the above-described configuration allows obtaining a shield effect which is effective for the solid-state image pickup element susceptible to noises, by forming, as shown in FIG. 14, a ground pattern 118 so as to substantially cover the printed circuit board 103 on a face of the printed circuit board 103 opposite to the electrical connecting face thereof and preferably connecting such ground pattern to a predetermined potential (including ground potential). In such case, the printed circuit board 103 may be so folded in a box shape, as shown in FIG. 15, as to substantially cover the solid-state image pickup package 101 in order to attain further enhanced shield effect.
Furthermore, thus formed ground pattern 118 may be provided, as shown in FIG. 16, with slit portions 119 so as to surround rear face areas corresponding to the rands, thereby preventing the heat loss in soldering the solid-state image pickup package 101 .
The above-mentioned ground pattern may be provided at least in a size approximately the same as that of the rear face of the solid-state image pickup package and directly behind the package, in order to prevent the noises entering the package from the rear face side thereof.
As explained in the foregoing, in the package for the solid-state image pickup element for use in an image pickup device including an image pickup optical system, a package of the chip carrier type containing a solid-state image pickup element, a position defining member for defining the position of the package relative to the optical system, and a printed circuit board having rands for electrical connection with the solid-state image pickup element, the package comprises a step difference between a mounting face on the rear face of the package for mounting the position defining member and a face of the package for electrical connection with the printed circuit board whereby such step difference can be selected close to the thickness of the position defining member and the dimension of the package can be uniquely and precisely determined to eliminate the dead space.
Also the dead space at the rear face side of the printed circuit board, which has been a drawback in the conventional configuration, can be eliminated since the electrode portions of the solid-state image pickup package are electrically connected at the front face of the printed circuit board.
Furthermore, a shield effect against noises can be obtained without utilizing a shield case.
Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims. | An image pickup device is provided with an optical system for taking the image of an object. A photoelectric converting element photoelectrically converts the object image taken by the optical system and an electric signal outputting board outputs an electrical signal from the photoelectric converting element. A position defining member defines the position of the optical system relative to the photoelectric converting element. The electric signal outputting board is positioned between the photoelectric converting element and the position defining member. | 8 |
PRIORITY TO RELATED APPLICATION(S)
[0001] This application is a divisional application of U.S. application Ser. No. 12/474,434, filed May 29, 2009, now pending, which claims the benefit of European Patent Application No. 08157757.9, filed Jun. 6, 2008. The entire contents of the above-identified applications are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The invention is directed generally to processes for the preparation of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acids and salts thereof and more particularly comprises a process for the preparation of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of the formula
[0000]
[0000] or of a salt thereof.
BACKGROUND OF THE INVENTION
[0003] Certain art, e.g., DE A1 3935934 discloses a preparation of 3-chloro-2-fluoro-5-trifluoromethyl-benzoic acid which comprises the conversion of 1,3-dichloro-2-fluoro-(trifluoromethyl)benzene with tert-butyl lithium/pentane and subsequent carbon dioxide treatment. However, this preparation process suffers from the use of corrosive chemicals at low temperatures of −78° C. and thus creates a scaling issue.
[0004] Accordingly, it would be advantageous to develop a process for the preparation of 3-chloro-2-fluoro-5-trifluoromethyl-benzoic acid compounds which could be performed on technical scale and overcome or avoid such known drawbacks in the art.
SUMMARY OF THE INVENTION
[0005] The process for the preparation of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of the formula
[0000]
[0000] or of a salt thereof comprises the conversion of 3-chloro-4-fluoro-benzo trifluoride of the formula
[0000]
[0006] The 3-chloro-4-fluoro-benzo trifluoride starting compound is commercially available or can be prepared according to U.S. Pat. No. 4,469,893 (1984) or WO1997024318 (1997).
[0007] In a further embodiment of the present invention the conversion is performed by either
[0000] a 1 ) deprotonating the 3-chloro-4-fluoro-benzo trifluoride with a metalorganic base followed by adding CO 2 as electrophile in an organic solvent at a reaction temperature of −100° C. to 25° C.
or
b 1 ) by forming a Grignard compound of the 3-chloro-4-fluoro-benzo trifluoride with an alkyl or an aryl magnesium halide in an organic solvent at a reaction temperature of 20° C. to 100° C. followed by adding CO 2 as electrophile in an organic solvent at a reaction temperature of −100° C. to 25° C.
DETAILED DESCRIPTION
[0008] The following definitions are set forth to illustrate and define the meaning and scope of the various terms used to describe the invention herein. All references cited herein are hereby incorporated by reference in their entirety.
[0009] The term “alkyl” relates to a branched or straight-chain monovalent saturated aliphatic hydrocarbon radical of one to six carbon atoms, preferably one to four carbon atoms. This term is further exemplified by radicals as methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl and pentyl or hexyl and its isomers.
[0010] The term “aryl” relates to the phenyl or naphthyl group, preferably the phenyl group, which can optionally be mono-, di-, tri- or multiply-substituted by halogen, hydroxy, CN, halogen-C 1-6 -alkyl, NO 2 , NH 2 , N(H, alkyl), N(alkyl) 2 , carboxy, aminocarbonyl, alkyl, alkoxy, alkylcarbonyl, C 1-6 -alkylsulfonyl, SO 2 -aryl, SO 3 H, SO 3 -alkyl, SO 2 —NR′R″, aryl and/or aryloxy. Preferred aryl group is phenyl.
[0000] Step a 1 )
[0011] Suitable metalorganic bases for the deprotonation in step a) can be selected from lithium bases such as n-butyl lithium, s-butyl lithium, t-butyl lithium or alkalimetal-amines. More preferred is n-butyl lithium or lithium diisopropylamide, even more preferred n-butyl lithium. The term “alkalimetal-amine”, refers to a secondary amine substituted by an alkali metal as defined herein. The “alkalimetal-amine” is either prepared in situ or ex situ prior to use, following synthetic routes well known by the person skilled in the art or it is available commercially. The most preferred alkali metal to be used is lithium. Exemplary alkalimetal-amine includes lithium adducts of dicyclohexyl amine, diisopropyl amine, tetramethyl piperidine or hexamethyl disilazane. The most preferred alkalimetal-lithium is lithium diisopropyl amine. The term “alkali metal” includes lithium, sodium and potassium. Preferable alkali metal is lithium or sodium.
[0012] “Secondary amine” refers to an amine of formula (a)
[0000]
[0000] where R a and R b may be the same or different and are independently selected from (C 1 -C 6 ) alkyl, (C 3 -C 6 ) cycloalkyl or —Si(C 1 -C 6 ) alkyl, or R a and R b taken together with the nitrogen atom to which they are attached, form a (C 4 -C 8 )heterocycloalkane optionally containing an additional heteroatom selected from O or N. Representative examples include, but are not limited to, piperidine, 4-methyl-piperidine, piperazine, pyrrolidine, morpholine, dimethylamine, diethylamine, diisopropylamine, dicyclohexylamine, ethylmethylamine, ethylpropylamine, methylpropylamine and hexamethyl disilazide. Preferably, the secondary amine is chosen from diethylamine, diisopropylamine, dicyclohexylamine, ethylmethylamine, ethylpropylamine and methylpropylamine.
[0013] The metalorganic base can be used in an amount of 0.9 to 2.0 equivalents, preferably 1.0 to 1.5 equivalents and even more preferred in an amount of 1.0 to 1.1 equivalents related to the starting compound 3-chloro-4-fluoro-benzo trifluoride.
[0014] The deprotonation as a rule is performed in a suitable organic solvent, preferably in an ether such as in tetrahydrofuran, 2-methyltetrahydrofuran, methoxycyclopentane, diethyl ether t-butyl methyl ether, or dioxane or in a combination of ethers with hydrocarbons such as toluene, pentane, hexane, cyclohexane or methyl cyclohexane, but preferably in tetrahydrofuran, 2-methyltetrahydrofuran or tetrahydrofuran/hexane.
[0015] The reaction temperature for the deprotonation is selected between −100° C. and 25° C., preferably between −78° C. and −50° C., even more preferred between −70° C. and −78° C.
[0016] The subsequent reaction with CO 2 can happen by slowly adding the reaction mixture to a solution of CO 2 in an organic solvent, which as a rule is the same solvent as for the deprotonation reaction. The reaction temperature is kept in the same range as outlined above for the deprotonation reaction.
[0017] Upon completion of the reaction the target product can be isolated after acidifying the reaction mixture upon the addition of a protic acid and/or water and after extraction from the aqueous phase with a suitable organic solvent such as with t-butyl methyl ether.
[0018] Protic acid refers to Brønsted acid that donates at least one proton (H+) to another compound. Typical protic acids include aqueous mineral acids such as nitric acid, sulfuric acid, phosphoric acid, hydrogen halides acid, organic acids such as methanesulfonic acid, benzenesulfonic acid, acetic acid, citric acid and the like and complex acids such as tetrafluoro boronic acid, hexafluoro phosphoric acid, hexafluoro antimonic acid and hexafluoro arsenic acid. Preferred protic acids are citric acid, acetic acid and HCl.
[0000] Step b 1 )
[0019] The formation of the Grignard compound is usually performed with an alkyl or aryl magnesium halide, preferably in the presence of an amine base, preferably a secondary amine applying a reaction temperature of 20° C. to 100° C., preferably 20° C. to 60° C.
[0020] Suitable secondary amines have been listed under step a 1 . Preferred secondary amine is diisopropylamine.
[0021] Representative examples of alkyl or aryl magnesium halides include, but are not limited to, ethyl magnesium bromide, methyl magnesium bromide, methyl magnesium chloride, methyl magnesium iodide, propyl magnesium chloride, iso-propyl magnesium chloride, sec-butyl magnesium chloride, sec-butyl magnesium chloride, tert-butyl magnesium chloride, allyl magnesium chloride, allyl magnesium bromide, vinyl magnesium bromide, cyclopentyl magnesium chloride, hexyl magnesium chloride, benzyl magnesium chloride, phenyl magnesium bromide, phenyl magnesium chloride, p-toluoyl magnesium bromide, mesyl magnesium bromide. Preferred alkyl magnesium halide is ethyl magnesium bromide.
[0022] The same solvents as suggested for the deprotonation may be used for the formation of the Grignard compound. Preferred solvent is tetrahydrofuran.
[0023] The subsequent reaction with CO 2 can happen by slowly adding the reaction mixture to a solution of CO 2 in an organic solvent, which as a rule is the same solvent as for the deprotonation reaction.
[0024] The reaction temperature is selected between −100° C. and 25° C., preferably between −78° C. and −50° C., even more preferred between −70° C. and −78° C.
[0025] Upon completion of the reaction the target product can be isolated after acidifying the reaction mixture with a protic acid (e.g. aqueous HCl) and/or water and after extraction from the aqueous phase with a suitable organic solvent such as with t-butyl methyl ether.
[0026] In a further embodiment of the present invention the conversion is performed by a 2 ) transforming the 3-chloro-4-fluoro-benzo trifluoride of formula II into the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula
[0000]
[0000] and
b 2 ) oxidizing the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde with an oxidant to form the 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of formula I or of a salt thereof.
Step a 2 )
[0027] The transformation into the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula III is usually performed by deprotonating the 3-chloro-4-fluoro-benzo trifluoride with a metalorganic base followed by adding an electrophile selected from an N,N-dialkylformamide, an N,N-diarylformamide or N-alkoxy-N-alkyl formamides in an organic solvent at a reaction temperature of −100° C. to 25° C.
[0028] The deprotonation can be performed as outlined above for step a 1 .
[0029] The addition of the electrophile as a rule can happen at the same temperature and in the same solvent as described for the deprotonation reaction. Usually the electrophile is added in an amount of 0.9 to 5.0 equivalents, preferably 1.0 to 1.5 equivalents, even more preferred 1.0 to 1.1 equivalents relating to 1.0 equivalent of the starting compound.
[0030] Representative examples of N,N-dialkylformamides or N,N-diarylformamides include, but are not limited to, N,N-diphenylformamide, N-Methylformanilide, N,N-diethylformamide, N,N-dibutylformamide, 1-Formylpiperazine, 1,4-diformylpiperazine, N-Methylmorpholine, N-Methyl-N-(2-pyridyl)-formamide, N-Methylpiperidine, N,N-diisopropylformamide, 2-Methoxy-1-formyl-piperidine, N,N-diallylformamide, N,N-di-n-propyl-formamide, N,N-dibenzylformamide, 1-formyl-pyrrolidine.
[0031] Representative examples of N-alkoxy-N-alkyl formamides include, but are not limited to, N-methoxy-N-methyl formamide, N-benzyloxy-N-methyl formamide or N-ethoxy-N-methyl formamide. Preferred electrophile is N,N-dimethylformamide.
[0032] Usually a protic acid as quenching agent is added subsequent to the deprotonation and subsequent to the addition of the electrophile.
[0033] Protic acid refers to Brønsted acid that donates at least one proton (H+) to another compound. Typical protic acids include aqueous mineral acids such as nitric acid, sulfuric acid, phosphoric acid, hydrogen halides acid, organic acids such as methanesulfonic acid, benzensulfonic acid, acetic acid, citric acid and the like and complex acids such as tetrafluoro boronic acid, hexafluoro phosphoric acid, hexafluoro antimonic acid and hexafluoro arsenic acid. Preferred protic acids are citric acid, acetic acid and sulfuric acid.
[0034] Quenching is as a rule performed at a temperature of −78° C. to 25° C.
[0035] The 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula III can be isolated using methods known to the skilled in the art e.g. by way of extraction from the aqueous phase with a suitable organic solvent such as with t-butyl methyl ether CH 2 Cl 2 or toluene and subsequent removal of the solvent.
[0036] In a preferred embodiment the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula III is extracted from the aqueous reaction mixture with toluene. The concentrated toluene phase can then, without isolating the aldehyde, be used for the oxidation in step b 2 ).
[0000] Step b 2 )
[0037] The oxidant is selected from a compound which is able to transfer oxygen atoms such as from alkali- or alkali earth hypochlorites, -hypobromites, -chlorites, -chlorates, -persulfates or -permanaganates. Common representatives are sodium hypochlorite, calcium hypochlorite, sodium chlorate, calcium chlorate, potassium peroxymonosulfate (Oxone®) or potassium permanganate. Preferably sodium hypochlorite or sodium or potassium hypobromite may be used, whereby the latter two can be produced in situ by adding bromine to an aqueous solution of sodium or potassium hydroxide or by adding sodium or potassium bromide to an aqueous basic solution of sodium hypochlorite. Most preferred oxidant is sodium hypochlorite in combination with potassium bromide.
[0038] In a further preferred embodiment the reaction is performed in the presence of an aqueous alkali hydroxide base, preferably sodium hydroxide or potassium hydroxide, even more preferred in the presence of sodium hydroxide.
[0039] An additive selected from an alkali bromide and/or from TEMPO (2,2,6,6-Tetramethylpiperidinyloxy) can be used, whereby sodium bromide or potassium bromide are preferred and potassium bromide is the most preferred additive.
[0040] The oxidation can be performed in an aqueous solvent selected from water and mixtures thereof with a suitable organic solvent such as with N,N-dimethylformamide, dimethyl acetamide, acetonitrile, toluene, CH 2 Cl 2 or with mixtures of these organic solvents. Preferably the oxidation is performed in water or in a mixture of water and toluene.
[0041] A quenching agent, e.g. aqueous sodium sulfite may be added subsequent to the oxidation reaction.
[0042] The reaction temperature as a rule is chosen between 10° C. to 100° C., preferably between 10° C. and 60° C., more preferably at 20° C. to 50° C.
[0043] The isolation of the 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of formula I can preferably happen by separating off organic impurities from the reaction mixture (set at a pH of >11) with toluene, by acidifying the product containing aqueous phase to a pH<2 and by extracting the product from the aqueous phase with toluene.
[0044] In a preferred embodiment of the invention the isolated product can further be purified by crystallization with cyclohexane, heptane, methyl cyclohexane or mixtures thereof.
[0045] In a further embodiment of the present invention the conversion is performed by a 3 ) converting the 3-chloro-4-fluoro-benzo trifluoride of formula II into an alkali (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate of formula
[0000]
[0000] wherein M is an alkali metal atom;
b 3 ) transforming the alkali (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate of formula IV into the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula
[0000]
[0000] and
c 3 ) oxidizing the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of formula III with an oxidant to form the 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of formula I or of a salt thereof.
Step a 3
[0046] Step a 3 involves the conversion of the 3-chloro-4-fluoro-benzo-trifluoride of formula II into an alkali (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate of formula IV by
[0000] a 4 ) deprotonating the 3-chloro-4-fluoro-benzo trifluoride with a metalorganic base followed by
b 4 ) adding an electrophile selected from an N,N-dialkylformamide, an N,N-diarylformamide or N-alkoxy-N-alkyl formamides, in an organic solvent at a reaction temperature of −100° C. to 25° C., by
c 4 ) adding a protic acid as quenching agent and finally by
d 4 ) forming the alkali (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate of formula IV with an alkali pyrosulfite or an aqueous solution of a alkali hydrogen sulfite.
[0047] The deprotonation step, the addition of the electrophile and the quenching step can be performed as outlined above for step a 2 .
[0048] For the formation of the alkali (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate of formula IV in step d 4 ) usually an aqueous solution of sodium pyrosulfite is used. The transformation as a rule is performed in suitable organic solvent such as in toluene, at a reaction temperature of 0° C. to 50° C.
[0049] Upon completion of the reaction the product of step d 4 ) can be isolated by filtration from the reaction mixture.
[0000] Step b 3
[0050] The transformation of the alkali (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate of formula IV into the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula III is performed with an aqueous alkali hydroxide base, preferably sodium hydroxide or potassium hydroxide, even more preferred with sodium hydroxide.
[0051] The transformation as a rule is performed in the presence of a suitable water immiscible organic solvent such as in methylene chloride, toluene or TBME at a reaction temperature of −20° C. to 40° C.
[0052] The resulting 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of the formula III can be separated from the organic phase by removing the solvent.
[0000] Step c 3
[0053] The oxidation of the 3-chloro-2-fluoro-5-trifluoromethyl benzaldehyde of formula III to the 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of formula I or of a salt thereof can take place as outlined for the step b 2 ) above.
[0054] In a preferred embodiment of the invention the isolated product can further be purified by crystallization with cyclohexane, heptane, methyl cyclohexane or mixtures thereof.
[0055] The following examples serve to illustrate the invention in more detail. These examples are not intended to limit the scope of the invention in any manner.
EXAMPLES
Example 1.1
Synthesis of 3-chloror-2-fluoro-5-trifluoromethyl-benzaldehyde
[0056]
[0057] To a solution of 3-Chloro-4-fluoro-benzotrifluoride (59.9 g, 301.7 mmol) in THF (400 ml) was added at −78° C. n-BuLi (135.5 g, 309.7 mmol, 1.03 equiv.) dropwise over a period of ca. 30 min. The clear yellow solution was stirred for 30 min at −78° C. and a solution of DMF (24.5 g, 334.5 mmol, 1.11 equiv.) in THF (107 ml) were added dropwise, such as that the internal temperature stayed below −70° C. The light yellow reaction mixture was stirred for 1 h at −78° C. and was then warmed to 0° C. At this temperature the reaction mixture was quenched upon addition of an aqueous citric acid solution (600 ml, 15%). To this mixture, toluene (300 ml) was added; the organic phase was separated and washed with water (200 ml), whereas the aqueous phase was washed with toluene (300 ml). The combined organic phases were dried over sodium sulfate, and concentrated under vacuum to a volume of ca. 450 ml. To this solution was added a solution of sodium pyrosulfite (66.4 g, 331.8 mmol, 1.10 equiv.) in water (200 ml), whereupon a white precipitate was formed. The white suspension was stirred overnight; the precipitate was filtered off, washed with toluene (200 ml) and dried under vacuum (<50 mbar) for 3 h to yield the bi-sulfite intermediate (110 g, 110% yield). The obtained intermediate was taken up in CH 2 Cl 2 (350 ml) and treated with NaOH (2M) solution (310 ml, 620 mmol, 2.06 equiv.) and the bi-phasic mixture was stirred for 2 h. The phases were separated, the organic phase was washed with water (200 ml), dried over sodium sulfate and the solvent was removed under vacuum to yield the title compound as colorless oil (52.7 g, 77.1% yield). MS (EI): m/z 225 ([M−H] + , 100%). 1 H-NMR (CDCl 3 , 300 MHz): δ 10.38 (s, 1H), 8.07 (dd, 1H), 7.94 (dd, 1H).
Example 1.2
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde
[0058]
[0059] To a solution of 3-Chloro-4-fluoro-benzotrifluoride (5.0 g, 25.18 mmol) in THF (40 ml) was added at −78° C. n-BuLi (16.5 ml, 26.44 mmol, 1.05 equiv.) dropwise over a period of ca. 30 min. The clear yellow solution was stirred for 20 min at −78° C. and was then transferred dropwise via cannula to a pre-cooled (−78° C.) solution of DMF (2.14 ml, 27.7 mmol, 1.1 equiv.) in THF (75 ml) such that the internal temperature stayed below −65° C. The light yellow reaction mixture was stirred for 1 h at −78° C. and was then warmed to 0° C. At this temperature the reaction mixture was quenched upon addition of a solution of citric acid (14.54 g, 75.55 mmol, 3 equiv.) in water (50 ml). The organic phase was separated and washed with water (50 ml), whereas the aqueous phase was washed with TBME (50 ml). The combined organic phases were dried over sodium sulfate, filtered and the solvents were removed under vacuum to yield the crude title compound as yellow oil with a white precipitate (6.8 g, 119.2% yield). The crude product was distilled (Kugelrohr, 110-120° C., 1 mbar) to yield the title compound as colorless oil (4.52 g, 71.9% yield).
Example 2.1
Synthesis of sodium (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate
[0060]
[0061] To a solution of 3-Chloro-4-fluoro-benzotrifluoride (20.0 g, 100.7 mmol) in THF (200 ml) was added at −78° C. n-BuLi (1.6 M in hexanes, 66.1 ml, 105.7 mmol, 1.05 equiv.) over a period of ca. 20 min. The clear yellow solution was stirred for 30 min at −78° C. and a solution of DMF (8.54 ml, 110.8 mmol, 1.1 equiv.) in THF (100 ml) was added dropwise, such as that the internal temperature stayed below −70° C. The light yellow reaction mixture was stirred for 3 h at −78° C. and was then warmed to 0° C. At this temperature the reaction mixture was quenched upon addition of a solution of citric acid (58.13 g, 302.1 mmol, 3.0 equiv.) in water (400 ml) keeping the temperature below 5° C. The organic phase was separated and washed with water (300 ml), whereas the aqueous phase was washed with TBME (300 ml). The combined organic phases were dried over sodium sulfate, the solvents were removed under vacuum and the residue was treated with toluene (200 ml), whereupon a white precipitate was formed. The suspension was stirred for 15 min, the precipitate was filtered off and the mother liquor was treated by dropwise addition of a solution of sodium pyrosulfite (21.68 g, 111.8 mmol, 1.11 equiv.) in water (60 ml), whereupon a white suspension was formed. The suspension was stirred overnight (ca. 15 h), the precipitate was filtered off, washed with toluene (100 ml) and dried under vacuum to yield the title compound as a off-white crystalline compound (32.54 g, 97.7% yield). MS (EI): m/z 306.9 ([M−H] − , 100%). 1 H-NMR (DMSO, 300 MHz): δ 8.00-7.85 (m, 2H), 6.58 (d, 1H), 5.31 (d, 1H).
Example 2.2
Synthesis of sodium (3-chloro-2-fluoro-5-trifluoromethyl-phenyl)-hydroxy-methanesulfonate
[0062]
[0063] To a solution of 3-Chloro-4-fluoro-benzotrifluoride (5.0 g, 25.18 mmol) in THF (40 ml) was added at −78° C. n-BuLi (1.6 M in hexanes, 16.53 ml, 26.45 mmol, 1.05 equiv.) over a period of ca. 20 min. The clear yellow solution was stirred for 15 min at −78° C. and then transferred dropwise via cannula to a pre-cooled (−78° C.) solution of DMF (2.14 ml, 27.7 mmol, 1.1 equiv.) in THF (100 ml) such as that the internal temperature stayed below −65° C. The light yellow reaction mixture was stirred for 2 h at −78° C., was then warmed to 0° C. and quenched upon addition of a acetic acid (4.32 g, 75.54 mmol, 3.0 equiv.) and water (50 ml) keeping the temperature below 5° C. The turbid light yellow suspension was stirred for 2 h, the precipitate was filtered off with suction on a funnel with a fritted disk and the filter cake was washed with TBME (30 ml). The organic phase was separated and washed with water (50 ml), whereas the aqueous phase was washed with TBME (50 ml). The combined organic phases were dried over sodium sulfate, filtered and the solvents were removed under vacuum and the residue was treated with toluene (40 ml) and a solution of sodium pyrosulfite (5.42 g, 27.95 mmol, 1.11 equiv.) in water (12 ml) was added, whereupon a white suspension was formed. The suspension was stirred overnight (ca. 15 h), the precipitate was filtered off, washed with toluene (20 ml) and dried under vacuum to yield the title compound as a light yellow crystalline compound (7.82 g, 93.9% yield).
Example 3.1
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0064]
[0065] To an aqueous solution of sodium hypochlorite (100.3 g, 134.7 mmol, 1.22 equiv.) and potassium bromide (13.5 g, 112.3 mmol, 1.02 equiv.) in sodium hydroxide solution (32%, 34.5 g, 276.0 mmol, 2.50 equiv.) was added slowly (during 35 min) at 50° C. 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (25.0 g, 110.4 mmol). The reaction mixture was stirred at 50° C. for 60 min, cooled to ambient temperature and quenched upon addition of sodium sulfite (60.4 g, 474.5 mmol, 4.3 equiv.) in water (450 ml) to give a clear yellow solution. The solution was treated with HCl (25%, 100 ml, 788.7 mmol, 7.14 equiv.) adjusting the pH to <2. The formed precipitate was extracted with toluene (300 ml), the organic phase was washed with a solution of sodium chloride (5%, 100 ml), dried over sodium sulfate and the solvents were removed under vacuum to give the crude product as light yellow solid. The crude product was dissolved in hot cyclohexane (125 ml), and the solution was cooled to ambient temperature, whereupon white crystals precipitated. The crystals were filtered off, washed with cyclohexane (25 ml) and dried under vacuum until weight constancy to give the title compound as white crystals (23.0 g, 85.8% yield). MS (EI): m/z 241.1 ([M−H] − , 100%). 1 H-NMR (DMSO, 400 MHz): δ 14.08 (br s, 1H), 8.37-8.35 (dd, 1H), 8.11-8.09 (dd, 1H).
Example 3.2
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0066]
[0067] To an aqueous solution of sodium hypochlorite (15.3 ml, 25.7 mmol, 1.2 equiv.) and sodium bromide (2.6 g, 25.7 mmol, 1.2 equiv.) in sodium hydroxide solution (47%, 4.55 ml, 53.5 mmol, 2.50 equiv.) and water (12.5 ml) was added slowly (during 25 min) at 50° C. 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (5.0 g, 21.4 mmol). The reaction mixture was stirred at 50° C. for 60 min, cooled to ambient temperature and quenched upon addition of aqueous sodium sulfite solution (20%, 16.2 ml, 25.7 mmol, 1.2 equiv.) to give a light turbid suspension. The suspension was stirred for 15 min, treated with HCl (37%, 5.0 ml, 59.1 mmol, 2.76 equiv.) adjusting the pH to 1, whereupon a white precipitate formed. This precipitate was extracted with toluene (30 ml), the organic phase was washed with brine (30 ml), whereas the aqueous phase was washed with TBME (30 ml). The combined organic phases were dried over sodium sulfate, filtered and the solvent was removed under vacuum to give the crude product as light yellow solid (5.13 g, 98.8% yield). The crude product was dissolved in hot cyclohexane (25 ml), and the solution was cooled to ambient temperature, whereupon white crystals precipitated. The crystals were filtered off, washed with cyclohexane (5 ml) dried under vacuum until weight constancy to give the title compound as white crystals (3.65 g, 69.6% yield).
Example 3.3
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0068]
[0069] To an aqueous solution of sodium hypochlorite (15.3 ml, 25.7 mmol, 1.2 equiv.) and sodium bromide (2.6 g, 25.7 mmol, 1.2 equiv.) in sodium hydroxide solution (47%, 2.73 ml, 32.12 mmol, 1.50 equiv.) and water (12.5 ml) was added slowly (during 25 min) at 50° C. 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (5.0 g, 21.4 mmol). The reaction mixture was stirred at 50° C. for 60 min, cooled to ambient temperature and quenched upon addition of aqueous sodium sulfite solution (20%, 16.2 ml, 25.7 mmol, 1.2 equiv.) to give a light turbid suspension and stirred for 1 h. The suspension was stirred for 15 min, treated with HCl (37%, 4.0 ml, 47.3 mmol, 2.21 equiv.) adjusting the pH to 1, whereupon a white precipitate formed. This precipitate was extracted with TMBE (30 ml), the organic phase was washed with brine (30 ml), whereas the aqueous phase was washed with TBME (30 ml). The combined organic phases were dried over sodium sulfate, filtered and the solvent was removed under vacuum to give the crude product as light yellow solid (5.12 g, 98.6% yield). The crude product was dissolved in hot methylcyclohexane (25 ml), and the solution was cooled to ambient temperature, whereupon white crystals precipitated. The crystals were filtered off with suction on a funnel with a fritted disk, washed with methylcyclohexane (5 ml) dried under vacuum until weight constancy to give the title compound as white crystals (4.27 g, 81.6% yield).
Example 3.4
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0070]
[0071] A: A solution of n-BuLi in hexanes (1.6 M, 6.5 1, 10.24 mol, 1.024 equiv.) was added under nitrogen to a stirred solution of 3-chloro-4-fluoro-benzotrifluoride (1.985 kg, 10 mol) in THF (10 1) maintaining the temperature below −50° C. After complete addition of the benzotrifluoride, the resulting reaction mixture was stirred for 15 min at −55° C. and DMF was added in a slow stream. After complete addition, the reaction mixtures was stirred for 15 min and hydrolyzed upon addition of sulfuric acid (20%, 5 1). The organic layer was separated, the THF/hexanes were removed under vacuum and the residual liquid was distilled under vacuum to yield a clear oil. This material was taken through to the benzoic acid without determination of the yield as described in section B.
[0072] B: A solution of sodium hypobromite was prepared by adding bromine (1.15 kg, 7.18 mol) to a gently cooled mixture of sodium hydroxide (47%, 1.933 kg) in water (7.735 1). To this solution was added 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (1.50 kg, 6.62 mol) in a stream, whereupon the reaction mixture warmed to about 40-50° C. When the addition was complete, the mixture was stirred for a further 15 min and then acidified with hydrochloric acid (36%), whereupon the product precipitated. The acid was collected by filtration, was pressed as dry as possible on the filter and was then azeotropically dried using petroleum ether (80-100° C.). After removal of the water, the remaining petrol solution was decanted from any inorganic residue and allowed to crystallize. The product was filtered, washed well with petroleum ether (40-60° C.) and dried in a vacuum oven to give the product as white crystals (1.5 kg, 61.8% yield based on 3-chloro-4-fluoro-benzotrifluoride).
Example 3.5
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0073]
[0074] To a solution of 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (4.2 g, 18.5 mmol) in DMF (21 ml) and CH 2 Cl 2 (21 ml) was added potassium peroxomonosulfate (11.4 g, 18.5 mmol, 1.0 equiv.) whereupon the temperature rose from 25 to 34° C. The white suspension was stirred for 2 h, the white solid was filtered off, the filter cake was washed with CH 2 Cl 2 (25 ml) and the solvent was removed under vacuum. The obtained residue was dissolved in TBME (50 ml) and the pH was adjusted to 14 upon addition of NaOH (2M, 22.7 ml, 45.4 mmol, 2.45 equiv.). The aqueous phase was separated, washed with TBME (25 ml), whereas the organic phases were washed with water (25 ml). The combined aqueous phases were acidified upon addition of HCl (37%, 8.4 ml, 5.35 equiv.) and extracted with TBME (50 ml). The organic phase was washed three times with brine (75 ml), whereas the aqueous phases were washed with TBME (25 ml). The combined organic phases were dried over sodium sulfate, which was filtered off, washed with TBME (20 ml) and the solvents were removed under vacuum to yield the 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid as white solid (4.2 g of crude product, 93.4% yield). The crude product was dissolved in hot methyl cyclohexane (20 ml), the oil bath was removed and the suspension was slowly cooled to ambient temperature, whereupon white crystals precipitated. The white suspension was stirred in an ice bath for 2 h, the crystals were filtered off, washed with methyl cyclohexane (5 ml) and dried under vacuum until weight constancy to yield the title compound as white crystals (3.1 g, 68.9% yield).
Example 3.6
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0075]
[0076] To a solution of 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (1.0 g, 4.41 mmol) in acetone (15 ml) and water (3 ml) was added potassium permanganate (0.837 g, 5.3 mmol, 1.2 equiv.) and the corresponding dark violet reaction mixture was stirred for 30 min to achieve full conversion. The solvents were removed under vacuum and the dark suspension was quenched upon addition of sodium sulfite solution (sat., 20 ml). The dark violet solid was filtered off and washed with water (10 ml). The turbid light brown mother liquor was treated with HCl (25%, 3 ml, 92.3 mmol, 20.9 equiv) adjusting the pH to 1 and CH 2 Cl 2 (50 ml) was added. The phases were separated, the organic phase was washed with water (20 ml), whereas the aqueous phase was washed with CH 2 Cl 2 (20 ml). The combined organic phases were dried over sodium sulfate, filtered and the solvent was exchanged under vacuum with methyl cyclohexane (35 ml). The turbid suspension was concentrated under vacuum, the white precipitate was filtered off and the crystals were dried under vacuum until weight constancy to yield the product as white crystals (1.02 g, 93.8% yield).
Example 3.7
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0077]
[0078] To a solution of diisopropyl amine (19.79 ml, 140 mmol, 1.4 equiv.) in 100 ml THF was added at −78° C. n-BuLi (1.6 M in hexane, 81.25 ml, 130 mmol, 1.3 equiv.) within 25 min, the light yellow solution was stirred for 30 min at −78° C. and a solution of 3-chloro-4-fluoro benzotrifluoride (19.86 g, 100 mmol, 1 equiv.) in 100 ml of THF was added dropwise within 25 min keeping the temperature between −73 and −76° C. The resulting yellow solution was stirred for 1 h at −78° C., transferred into an addition funnel which was cooled with an acetone/dry ice mixture and added to a cold (−78° C.) mixture of CO 2 (44.0 g, 1000 mmol, 10 equiv.) in 100 ml of THF within 1 h keeping the temperature between −75 and −78° C. Afterwards the reaction mixture was transferred into an addition funnel and added to a solution of HCl (aq., 2M, 163 ml) within 15 min at −4° C., stirred for 15 min and transferred into a separation funnel. After separation of the phases, the aqueous phase was extracted with TBME (300 ml), the combined organic phases were dried over sodium sulfate (370 g), filtered with suction on funnel with a fritted disk, washed with TBME (100 ml in total) and the TBME was removed under vacuum to yield a light yellow solid (23.48 g of crude product, 96.8% yield). The crude product was treated with methyl cyclohexane (117 ml) and heated in a pre-heated oil bath to reflux. After 5 min, a brown clear solution was obtained, the oil bath was removed, the reaction mixture was cooled to ambient temperature, seeding crystals (2 mg) were added and the mixture was stirred overnight at ambient temperature. After 17 h the off-white suspension was stirred in an ice bath (0-5° C.) for two hours, the obtained crystals were filtered off, the crystals were washed with cold methyl cyclohexane (39 ml) and the crystals were dried until weight constancy to yield the product as white crystals (18.75 g, 77.3% yield).
Example 3.8
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0079]
[0080] To a mixture of ethyl magnesium bromide solution (6.25 ml, 6.25 mmol, 1.25 equiv., 1M in THF) and diisopropyl amine (77.7 μl, 0.5 mmol, 0.1 equiv.) was added 3-chloro-4-fluoro-benzo trifluoride (0.99 g, 5 mmol in THF (2 ml)) at ambient temperature and the mixture was heated in an oil bath to 50° C. for 13 h. The brown clear reaction mixture was cooled to 0-5° C., was transferred into a syringe and added dropwise to a solution of CO 2 (2.2 g, 50 mmol, 10 equiv.) in THF (5 ml) at −70° C. and stirred for 15 min. To the brown suspension was added HCl (1M, 14 ml) and the phases were separated. The aqueous phase was extracted with TBME (10 ml), the combined organic phases were dried over sodium sulfate, filtered, washed with TBME and the solvents were removed under vacuum to yield a dark brown oil (0.97 g of the crude product). The crude product was treated with methyl cyclohexane (4.4 ml) and heated in a pre-heated oil bath to reflux. After 5 min, a brown clear solution was obtained, the oil bath was removed, the reaction mixture was cooled to ambient temperature and the formed suspension was stirred overnight at ambient temperature. After 18 h the brown suspension was stirred in an ice bath (0-5° C.) for two hours, the obtained crystals were filtered off, the crystals were washed with cold methyl cyclohexane (1.6 ml) and the crystals were dried until weight constancy to yield the product as white crystals (0.46 g, 38.2% yield).
Example 3.9
Synthesis of 3-chloro-2-fluoro-5-trifluoromethyl-benzoate dicyclohexyl-ammonium
[0081]
[0082] To a solution of 3-chloro-2-fluoro-5-trifluoromethyl-benzaldehyde (23.0 g, 101.5 mmol) in DMF (110 ml) and CH 2 Cl 2 (110 ml) was added potassium peroxomonosulfate (62.4 g, 101.5 mmol, 1.0 equiv.) whereupon the temperature rose from 25 to 34° C. The white suspension was stirred for 2.5 h, the white solid was filtered off, the filter cake was washed with CH 2 Cl 2 (50 ml) and the solvent was removed under vacuum. The obtained residue was dissolved in TBME (240 ml) and the pH was adjusted to 14 upon addition of NaOH (2M, 101.5 ml, 203.0 mmol, 2.0 equiv.). The aqueous phase was separated, washed with TBME (75 ml), whereas the organic phases were washed with water (75 ml). The combined aqueous phases were acidified upon addition of HCl (25%, 52.8 ml, 4.0 equiv.) and extracted with TBME (200 ml). The organic phase was washed three times with brine, whereas the aqueous phases were washed with TBME (100 ml). The combined organic phases were dried over sodium sulfate, which was filtered off, washed with TBME (50 ml) and the solvents were removed under vacuum to yield the 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid as white solid (21.35 g of crude product, 86.7% yield). The crude product was dissolved in hot acetone (200 ml) and dicyclohexyl diamine (17.5 ml, 88 mmol, 1.0 equiv.) was added at reflux temperature and the mixture was stirred for 20 min, whereupon white crystals precipitated. The oil bath was removed, the suspension was slowly cooled to ambient temperature, the crystals were filtered off, washed with acetone (60 ml) and dried under vacuum until weight constancy to yield the title compound as white crystals (35.8 g, 83.2% yield). MS (EI): acid: m/z 241.0 ([M−H] − , 100%), amine: m/z 182.0 ([M+H] + , 100%). 1 H-NMR (CDCl 3 , 400 MHz): δ 9.57 (br s, 2H), 7.96 (dd, 1H), 7.64 (dd, 1H), 3.07 (m, 2H), 2.09 (m, 4H), 1.81 (m, 4H), 1.65 (m, 2H), 1.58-1.40 (m, 4H), 1.35-1.05 (m, 6H).
Example 3.10
[0083] Telescoped process for the preparation of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid
[0000]
[0084] To a solution of 3-chloro-4-fluoro-benzotrifluoride (59.9 g, 0.302 mol) in THF (350 ml) was added dropwise at −73 to −80° C. 200 ml of n-BuLi (1.6 M in hexanes; 200 ml, 0.32 mol, 1.06 equiv.) within 1 hour. The clear yellow solution was stirred for 30 min at −75° C. and a solution of DMF (24.5 g, 0.335 mol, 1.11 equiv.) in THF (100 ml) was then added dropwise within 30 minutes at −74 to −78° C. The slightly yellow reaction mixture was stirred for 1 h at −75° C. and was then warmed to 0° C. and quenched at this temperature by dropwise addition of aqueous citric acid solution (30%, 300 ml). The resulting biphasic mixture was warmed to 20 to 25° C. and the layers were then allowed to separate. The lower aqueous layer was removed and the organic layer diluted with toluene (300 ml) and then washed with water (200 ml). The organic layer was concentrated under reduced pressure and with a jacket temperature of 60° C. to yield 85.2 g of a slightly yellow oil with an aldehyde content of ˜76% (w/w) (according to 1 H NMR). This oil was then added within 30 to 60 minutes at 30 to 50° C. to a stirred solution of sodium hypo-chlorite (10% in H 2 O; 230 g, 0.309 mol), potassium bromide (31.8 g, 0.266 mol) and sodium hydroxide (28% in H 2 O; 92 g, 0.644 mol) in water (220 ml). The resulting mixture was cooled to 20-25° C. and then quenched by addition of aqueous sodium sulfite solution (32 g Na 2 SO 3 in 355 ml water). The mixture was treated with toluene (350 ml) and the biphasic mixture stirred for 10 minutes. The lower product-containing aqueous layer was separated and washed with toluene (350 ml). The aqueous layer was acidified to pH 2 using sulfuric acid (20% in H 2 O; 240 g) and then extracted with toluene (450 ml). From the organic layer toluene was completely distilled off under reduced pressure. The residue (59 g) was dissolved at reflux temperature in a mixture of cyclohexane (141 ml) and heptane (141 ml). The clear solution was then cooled to −10° C. within 6 hours whereupon crystals precipitated. The crystals were filtered off, washed with cyclohexane/heptane 1:1 and dried at 50° C. and 30 mbars over night to yield the title compound as colorless crystals (55.8 g, 76% yield) with a purity of 100% (HPLC, area %). | The present invention comprises a process for the preparation of 3-chloro-2-fluoro-5-trifluoromethyl benzoic acid of the formula
or of a salt thereof 3-Chloro-2-fluoro-5-trifluoromethyl benzoic acid or salts thereof are versatile intermediates for the preparation of active pharmaceutical or agrochemical agents. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Provisional Patent Application Nos. 61/498,390, filed on Jun. 17, 2011, and 61/645,970, filed on May 11, 2012, which are incorporated by reference herein.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention relates to conjugated polymers and methods of making the same.
[0004] 2. Related Art
[0005] Organic π-conjugated polymers are attractive materials for use in the active layer, as they combine good absorption and emission characteristics with efficient charge carrier mobility and have the ability to be solution processed onto flexible substrates. Recent advances in the field have seen organic field effect transistors (OFET) achieve charge carrier mobility on the order of 1.0 cm 2 V −1 s −1 [1] and organic photovoltaic (OPV) devices reach power conversion efficiencies over 7% [2]. While these results are promising for the field, there still exits a complexity of correlating molecular structure to optical and electronic properties. Among the available narrow band-gap materials, donor-acceptor copolymers based on cyclopenta[2,1-b:3,4-b′]dithiophene (CDT) and benzothiadiazole (BT) have attracted considerable attention due to the high charge carrier mobility and excellent photovoltaic performance. Müllen and co-workers have eloquently demonstrated that CDT-BT copolymers with linear side chains and high molecular weights, p-type FETs with mobilities on the order of 1.4-3.3 cm 2 [3].
[0006] The incorporation of a nitrogen atom into the acceptor unit of CDT-BT copolymers results in the narrowing of the optical bandgap and the emergence of these materials to selectively bind Lewis acids [4]. The replacement of the BT unit with the pyridal[2,1,3]thiadiazole (PT) acceptor unit results in a higher electron affinity across the polymeric backbone leading to a decreased LUMO level of polymer. Copolymers based on PT and carbazole reported by Lerclerc et al. [5] have fairly low molecular weights (ca. 4-5 kDa), and the efficiencies of the fabricated solar cells (under 1%) are much lower than predicated. You and co-workers have demonstrated that by introducing two alkyl chains to the 4-position of the thienyl unit could lead to a more soluble PT based acceptor (DTPyT), and allows access to polymers with high molecular weights and excellent photovoltaic efficiency up to 6.32% [6]. In each case, however, the nature of the step-growth polymerization strategy leads to these polymer systems having a regiorandom origination of the pyridal-N atom along the polymeric backbone.
SUMMARY
[0007] The inventors understand that regioregularity can have a great impact on the properties of polymers [7]. For instance, enhanced regioregularity of poly(3-alkylthiophene) can impart to polymers a higher crystallinity, red-shifted optical absorption, higher conductivity, and smaller band-gap [8]. The inventors have surmised that for a polymer based on an asymmetric PT unit, a regioregular backbone structure with more effective electron localization can result in a higher charge carrier mobility and enhanced photovoltaic performance. Recognizing that for the copolymerization of distannyl CDT monomers and 4,7-dibromo-pyridal[2,1,3]thiadiazole (PTBr 2 ) as starting material, the resulted polymer would not be truly random because the bromine at the electron-deficient C4-position of PTBr 2 is more favorable for coupling than the C7-position [9], the inventors take advantage of this difference by preparing regiochemically precise backbones of PT-based polymers using specific synthetic procedures.
[0008] In one aspect, a method of preparing a regioregular polymer is provided. The method includes regioselectively preparing a monomer; and reacting the monomer to produce a polymer that includes a regioregular conjugated main chain section.
[0009] In a further aspect, a regioregular polymer that includes a regioregular conjugated main chain section is provided. Also provided is an electronic device that includes the regioregular polymer.
[0010] In some embodiments, the regioregular polymer includes a regioregular conjugated main chain section having a repeat unit that includes a pyridine of the structure
[0000]
[0000] where a) Ar is a substituted or non-substituted aromatic functional group, or Ar is nothing and the valence of the pyridine ring is completed with hydrogen, and b) the pyridine is regioregularly arranged along the conjugated main chain section. The regioregularity of the main chain section can be 95% or greater, and the charge carrier mobility of the regioregular polymer can be greater than the charge carrier mobility of a regiorandom polymer of similar composition. In some embodiments of the regioregular polymer, the repeat unit further includes a dithiophene of the structure
[0000]
[0000] where a) each Ar is independently a substituted or non-substituted aromatic functional group, or each Ar is independently nothing and the valence of its respective thiophene ring is completed with hydrogen, b) each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, and c) X is C, Si, Ge, N or P.
[0011] In some embodiments that include the pyridine and/or the dithiophene, each substituted or non-substituted aromatic functional group of the pyridine and the dithiophene independently includes one or more alkyl or aryl chains. In particular embodiments, the one or more alkyl or aryl chains are each independently a C 6 -C 30 substituted or non-substituted alkyl chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3).
[0012] In some embodiments that include the dithiophene, the substituted or non-substituted alkyl, aryl or alkoxy chain can be a C 6 -C 30 substituted or non-substituted alkyl, aryl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3).
[0013] In some embodiments that include the dithiophene, X can be C or Si.
[0014] In some embodiments of the regioregular polymer that include the pyridine, the pyridine is a pyridine unit of Table 1 (which is described below). In some embodiments, the repeat unit further includes a dithiophene unit of Table 2 (which is described below). In certain embodiments, the pyridine unit is
[0000]
[0000] and the dithiophene unit is
[0000]
[0000] wherein each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain. In some embodiments, the substituted or non-substituted alkyl, aryl or alkoxy chain is a C 6 -C 30 substituted or non-substituted alkyl, aryl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3). In some embodiments, X is C or Si. In particular embodiments, each R is C 12 H 25 , each R is 2-ethylhexyl, or each R is PhC 6 H 13 .
[0015] In some embodiments of the regioregular polymer, the repeat unit includes
[0000]
[0000] where each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, and X is C, Si, Ge, N or P. In some embodiments, the substituted or non-substituted alkyl, aryl or alkoxy chain is a C 6 -C 30 substituted or non-substituted alkyl, aryl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3). In some embodiments, X is C or Si. In particular embodiments, each R is C 12 H 75 , each R is 2-ethylhexyl, or each R is PhC 6 H 13 .
[0016] A device including any regioregular polymer described herein is provided. The device can be, but is not limited to, a field effect transistor, organic photovoltaic device, polymer light emitting diode, organic light emitting diode, organic photodetector, or biosensor. In the device, the regioregular polymer can form an active semiconducting layer.
[0017] The term “regioregular,” “regioregularly” or “regioregularity” in relation to a polymer or a section of a polymer means the non-random orientation or arrangement of the pyridal-N along the polymer backbone. In some regioregular embodiments, the nitrogen atom of the pyridine faces in the same direction in all or a majority of the repeat units of the polymer or polymer section. For example, in the repeat unit of Scheme 1 below, the pyridal nitrogen atom of the PT unit faces the CDT unit. If we define the end of PT next to the pyridal nitrogen atom as the head, and the other end as the tail, then all or a majority of the PT units in the copolymers of Scheme 1 adopted a head-to-tail arrangement next to each other. In other regioregular embodiments, all or a majority of the repeat units of the polymer or polymer section have two pyridine units, with the nitrogen atoms of the pyridine units oriented toward each other. For example, in the repeat unit of Scheme 2 below, the pyridal nitrogen atom of one PT unit is oriented towards the pyridal nitrogen atom of the other PT unit, which is a head-to-head connection through the CDT unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
[0019] FIG. 1 is a panel of 1 H NMR spectra of P1b, P2b and P3b in d-TCE at 110° C.;
[0020] FIG. 2 is a panel of UV-Vis spectra of P1a, P2a and P3a (a) in o-DCB solutions at 25° C. and (b) as casting films;
[0021] FIG. 3 is a panel showing output (a) and transfer (b) characteristics of FET devices based on P1a with PPCB as passivation layer;
[0022] FIG. 4 is a panel of UV-vis spectra of polymers (a) P1a, (b) P1b, (c) P2a, (d) P2b, (e) P3a and (f) P3b in o-DCB solutions at 25 or 110° C., and in films as casting (a.c.) or after thermal annealing (t.a.) at 110° C. for 15 min;
[0023] FIG. 5 is a panel of DSC curves of polymers with C12 side chain (a) and C16 side chain (b);
[0024] FIG. 6 is a panel of CV curves of polymers with C12 side chain (a) and C16 side chain (b);
[0025] FIG. 7 is a schematic drawing of a device structure with PPCB passivation;
[0026] FIG. 8 is a schematic drawing of a device structure with OTS-8 passivation; and
[0027] FIG. 9 is a schematic drawing of a bottom-gate, bottom contact device structure.
[0028] FIG. 10 is a composite drawing of GPC profiles of copolymers with chloroform as eluent.
[0029] FIG. 11 is a composite drawing of DSC characteristics of copolymers.
[0030] FIG. 12 is a composite drawing of UV-Vis spectra of PIPT-RG and PIPT-RA films (thickness ˜30 nm).
[0031] FIG. 13 is a panel of (a) CV curves and (b) UPS measurements of polymer films.
[0032] FIG. 14 is a panel of output and transfer characteristics (V D =−60 V) for FETs based on PIPT-RG (black dot) and PIPT-RA (red dot) at room temperature (a) and (d), thermal annealed at 100° C. for 10 min (b) and (e), and thermal annealed at 150° C. for 10 min (c) and (f). FET with channel L=20 μm, W=1 mm.
[0033] FIG. 15 is a composite drawing of grazing incident XRD of PIPT-RG and PIPT-RA polymer films.
[0034] FIG. 16 is a panel of topographic AFM images (2 μm×2 μm) of (a) PIPT-RG:PC 71 BM (1:4) and (b) PIPT-RA:PC 71 BM (1:4) (b) blend films.
[0035] FIG. 17 is a panel of TEM images of (a) PIPT-RG:PCBM (1:4) and (b) PIPT-RA:PCBM (1:4) (b) films.
[0036] FIG. 18 is a panel showing J-V characteristics (a) and IPCE (b) of thermal evaporated MoO x PSC devices based on regioregular and regiorandom PIPT polymers.
[0037] FIG. 19 is a panel showing J-V characteristics (a) and IPCE (b) of solution-processed MoO x PSC devices based on regioregular and regiorandom PIPT polymers.
[0038] FIG. 20 is a panel showing J-V characteristics of devices (a) post-thermal annealing, and (b) with additive.
[0039] FIG. 21 is a panel showing J-V characteristics (a) and IPCE (b) of inverted structure devices based on PIPT-RG polymer
[0040] FIG. 22 is a composite drawing of density-voltage (J-V) characteristics of PSC devices based on PSDTPTR-EH (A) and PSDTPT2-EH (B) copolymers.
[0041] FIG. 23 is a panel showing molecular structures of polymers and decyl(trichloro)silane, and device architecture.
[0042] FIG. 24 is a panel showing (a) the transfer characteristic of an organic TFT after annealing at 350° C., and b) the output characteristic of the same OTFT.
[0043] FIG. 25 are atomic force microscopy images of (a) the height image of a polymer film after 350° C. annealing obtained by the tapping mode of AFM, and (b) the phase image correlated to 24(a).
[0044] FIG. 26 is a panel of (a) out-of-plane XRD spectra after annealing at various temperatures, and (b) correlated in-plane XRD.
[0045] FIG. 27 is a composite drawing of contact resistances at different annealing temperatures obtained by transfer line measurement.
DETAILED DESCRIPTION
[0046] In the method of preparing a regioregular polymer, a monomer is regioselectively prepared. In some embodiments, the monomer is prepared by reacting halogen-functionalized PT with organotin-functionalized cyclopenta[2,1-b:3,4-b′]dithiophene. The reaction can be carried out at a temperature in the range of about 50° C. to about 150° C., and the regioselectivity of the reaction can be 95% or greater. In other embodiments the monomer is prepared by reacting halogen-functionalized PT with organotin-functionalized indaceno[1,2-b:5,6-b′]dithiophene (IDT), where the reaction can be carried out at a temperature in the range of about 50° C. to about 150° C. and the regioselectivity of the reaction can be 95% or greater. In other embodiments the monomer is prepared by reacting halogen-functionalized PT with organoboron-functionalized cyclopenta[2,1-b:3,4-b′]dithiophene or organboron-functionalized indaceno[1,2-b:5,6-b′]dithiophene (IDT), where the reaction can be carried out at a temperature in the range of about 50° C. to about 150° C. and the regioselectivity of the reaction can be 95% or greater. In some embodiments the monomer is prepared by reacting halogen-functionalized PT with cyclopenta[2,1-b:3,4-b′]dithiophene or indaceno[1,2-b:5,6-b′]dithiophene (IDT) by direct arylation polyerization, in which direct arylation allows the formation of carbon-carbon bonds between aromatic units having activated hydrogen atoms without the use of organometallic intermediates, where the reaction can be carried out at a temperature in the range of about 50° C. to about 150° C. and the regioselectivity of the reaction can be 95% or greater.
[0047] The halogen-functionalized PT can have the following structure:
[0000]
[0000] where X 1 and X 2 are each independently a halogen, and in particular embodiments can be I, Br, Cl, or CF 3 SO 3 .
[0048] The organotin-functionalized cyclopenta[2,1-b:3,4-b′]dithiophene can have the following structure:
[0000]
[0000] or the organotin-functionalized indaceno[1,2-b:5,6-b′]dithiophene can have the following structure:
[0000]
[0000] where each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, each R 2 is independently methyl or n-butyl, and X is C, Si, Ge, N or P. In some embodiments, the R groups can be the same and the R 2 groups can be the same.
[0049] The term “alkyl” refers to a branched or unbranched saturated hydrocarbyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, octyl, decyl and the like.
[0050] The term “aryl” refers to an aromatic hydrocarbyl group containing a single aromatic ring or multiple aromatic rings that are fused together, linked covalently, or linked to a common group such as a methylene or ethylene moiety. The term “alkoxy” refers to an alkyl group bound through a single, terminal ether linkage. The term “substituted” refers to a hydrocarbyl group in which one or more bonds to a hydrogen atom contained within the group is replaced by a bond to a non-hydrogen atom of a substituent group. Examples of non-hydrogen atoms include, but are not limited to, carbon, oxygen, nitrogen, phosphorus, and sulfur. Examples of substituent groups include, but are not limited to, halo, hydroxy, amino, alkoxy, aryloxy, nitro, ester, amide, silane, siloxy, and hydrocarbyl groups. The substituent can be a functional group such as hydroxyl, alkoxy, thio, phosphino, amino, or halo.
[0051] In particular embodiments of the cyclopenta[2,1-b:3,4-b′]dithiophene or indaceno[1,2-b:5,6-b′]dithiophene: the substituted or non-substituted alkyl, aryl or alkoxy chain can be a C 6 -C 30 substituted or non-substituted alkyl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n =2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3); and/or X can be Si.
[0052] In some embodiments, the halogen-functionalized PT and/or the organotin-functionalized cyclopenta[2,1-b:3,4-b′]dithiophene are compounds of Scheme 1 or 2. In other embodiments, the halogen-functionalized PT and/or the organotin-functionalized indaceno[1,2-b:5,6-b′]dithiophene are compounds of Scheme 4.
[0053] The regioselectively prepared monomer can have the following structure:
[0000]
[0000] where each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, each R 2 is independently methyl or n-butyl, X is C, Si, Ge, N or P, and X 2 is a halogen. In particular embodiments, X 2 can be I, Br, Cl, or CF 3 SO 3 . In some embodiments, the monomer has the following structure:
[0000]
[0054] In these embodiments, each R or R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, and each R 2 is independently methyl or n-butyl. In some embodiments, the substituted or non-substituted alkyl, aryl or alkoxy chain can be a C 6 -C 30 substituted or non-substituted alkyl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), or —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3); and/or X can be Si. In some embodiments, the R groups can be the same, the R 1 groups can be the same, and the R 2 groups can be the same.
[0055] In the method, the monomer is regioselectively prepared, then the monomer is reacted or polymerized to form a regioregular polymer having a regioregular conjugated main chain section. To form the regioregular polymer when the monomer is a CDT-PT monomer, the monomer can be reacted to itself, or reacted to another monomer containing a cyclopenta[2,1-b:3,4-b]dithiophene unit. When the monomer is a PT-IDT-PT monomer, the monomer can be reacted to another monomer containing an IDT-PT unit. The polymerization reaction can take place at a temperature in the range of about 80° C. to about 200° C. when the monomer is a CDT-PT monomer, and can take place at a temperature in the range of about 80° C. to about 200° C. when the monomer is a PT-IDT-PT monomer. The regioregular conjugated main chain section can comprise 5-100, or more, contiguous repeat units. In some embodiments, the number of repeat units is in the range of 10-40 repeats. The regioregularity of the conjugated main chain section can be 95% or greater.
[0056] The regioregular polymer in some embodiments has a main chain section that includes a repeat unit containing a pyridine of the structure
[0000]
[0000] or a dithiophene of the structure
[0000]
[0000] or a combination thereof, where each Ar is independently nothing or a substituted or non-substituted aromatic functional group, each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, and X is C, Si, Ge, N or P. When Ar is nothing, the valence of the respective pyridine or thiophene ring is completed with hydrogen. In some embodiments, the R groups can be the same. The substituted or non-substituted aromatic functional group can include one or more alkyl or aryl chains, each of which independently can be a C 6 -C 30 substituted or non-substituted alkyl or aryl chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3). The substituted or non-substituted alkyl, aryl or alkoxy chain can be a C 6 -C 30 substituted or non-substituted alkyl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3).
[0057] In embodiments of the regioregular polymer, the repeat unit of the regioregular conjugated main chain section can contain a pyridine unit of Table 1, where each R is independently a substituted or non-substituted alkyl chain, which can be a C 6 -C 30 substituted or non-substituted alkyl chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3); in some embodiments, the R groups can be the same.
[0000]
TABLE 1
Examples of pyridine units
[0058] In embodiments of the regioregular polymer, the repeat unit of the regioregular conjugated main chain section can contain a dithiophene unit of Table 2, where each R is independently a substituted or non-substituted alkyl, aryl or alkoxy chain, which can be a C 6 -C 30 substituted or non-substituted alkyl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N (CH 3 ) 3 Br (n=2˜20), —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3); in some embodiments, the R groups can be the same, and in some embodiments, a repeat unit may contain any combination of a pyridine unit of Table 1 and dithiophene unit of Table 2.
[0000]
TABLE 2
Examples of dithiophene units
[0059] In some embodiments, the regioregular polymer comprises a regioregular conjugated main chain having a repeat unit of the following structure:
[0000]
[0000] where each R is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain, and X is C, Si, Ge, N or P. In particular embodiments, the repeat unit has the following structure:
[0000]
[0000] where each R 1 is independently hydrogen or a substituted or non-substituted alkyl, aryl or alkoxy chain. In some embodiments, the R groups can be the same, and the R 1 groups can be the same. In some embodiments, each R or R 1 can be a C 6 -C 30 substituted or non-substituted alkyl, aryl or alkoxy chain, —(CH 2 CH 2 O)n (n=2˜20), C 6 H 5 , —C n F (2n+1) (n=2˜20), —(CH 2 ) n N(CH 3 ) 3 Br (n=2˜20), or —(CH 2 ) n N(C 2 H 5 ) 2 (n=2˜20), 2-ethylhexyl, PhC m H 2m+1 (m=1-20), —(CH 2 ) n Si(C m H 2m+1 ) 3 (m, n=1 to 20), or —(CH 2 ) n Si(OSi(C m H 2m+1 ) 3 ) x (C p H 2p+1 ) y (m, n, p=1 to 20, x+y=3); and/or X can be Si. In some embodiments, the polymer is prepared by any of the methods described herein, or shown in Scheme 1, 2, or 4.
[0060] The charge carrier mobility of the regioregular polymer can be greater than the charge carrier mobility of a regiorandom polymer of similar composition.
[0061] Embodiments of the polymer may be incorporated in electronic devices. Examples of electronic devices include, but are not limited to, field effect transistors, organic photovoltaic devices, polymer light emitting diodes, organic light emitting diodes, organic photodetectors and biosensors.
[0062] The electronic devices can be solution coated, where the solution coating process can be, but is not limited to, the following: spin coating, ink jet printing, blade coating, dip coating, spraying coating, slot coating, gravure coating or bar coating.
[0063] The present invention may be better understood by referring to the accompanying examples, which are intended for illustration purposes only and should not in any sense be construed as limiting the scope of the invention.
Example 1
[0064]
[0065] To develop a region regular structure, the functionalized donor-acceptor (DA) monomer 2 was targeted as a polymerization precursor. The more stable tributyltin was used as the functional group in the CDT unit because trimethyltin is not very stable during the purification procedure. An optimized Stille cross-coupling procedure (Scheme 1) was conducted in comparatively mild reaction condition as low as 70° C., which would allow for the regioselectively more preferred reaction at the C4-position of Br/PT to form DA monomers 2a and 2b since more forcing conditions were needed for the C7-position. It was found that higher temperatures result in relatively complex mixtures that require tedious separation procedures. The isolation of 2a and 2b followed by microwave assisted Stille self-polymerization with Ph(PPh 3 ) 4 as catalyst in xylenes afforded regioregular P1a and P1b with precisely controlled PT regularity along polymer backbone. It was found that P1b with longer alkyl side chain yielded a higher molecular weight of 28.1 kDa than P1a with shorter alkyl side chains (15.4 kDa), a likely result of increased solubility during the polymerization reaction.
[0000]
[0066] Alternatively, the coupling of 1a and 1b with 2 equivalents of PTBr 2 and regioselective reaction of PTBr 2 in C4-position can lead to the symmetric acceptor-donor-acceptor (ADA) 3a and 3b (Scheme 2) in high yield, respectively. Two single sharp resonances at 8.57 ppm (H in PT unit) and 8.57 ppm (H in CDT unit) in the 1 H NMR spectra of both 3a and 3b match very well with their symmetric structures. Microwave assisted Stille polymerization of 3a and 3b with distannylated CDT monomer 4a and 4b yielded regiosymmetric polymers with high molecular weights of 27.1 kDa and 55.9 kDA for P2a and P2b, respectively.
[0067] For comparison, the regiorandom copolymers P3a and P3b (Scheme 3), in which the pyridal-N atom in the PT unit is randomly aligned along the polymer backbone, were synthesized via a one-pot polymerization of PTBr 2 with distannyl CDT 4a or 4b. The obtained P3a and P3b have molecular weights of 20.0 kDa and 40.2 kDA, respectively.
[0000]
[0068] To gain insight into the regioregularity of the polymer structures, high temperature 1 H NMR spectroscopy was utilized ( FIG. 1 ). The experiments where performed in deuterated tetrachloroethane (d-TCE) at 110° C. For all the three polymers P1b, P2b and P3b, the resonance at approximately δ 8.99 ppm could be assigned to the proton in PT unit, and the signal at 8.67 ppm could be assigned to the proton on the CDT moiety closest to the N atom of PT unit. The peaks from the proton in CDT unit situated away from the PT unit show slightly different chemical shifts for P1b (8.14 ppm), P2b (8.16 ppm) and P3b (8.15 ppm). In comparison to the narrow peaks for well-ordered P1b and P2b, the random P3b exhibits much broader peaks which might be generated from the complicated environment of the proton in CDT unit.
[0069] The influence of the regioregular structure on the effective n-conjugated properties could also be recognized in the UV-vis-near IR absorption of the three classes of polymers ( FIG. 2 ). In o-dichlorobenze solution and as thin films, the maximum absorption (λ max ) exhibits a gradual bathochromic shift from 825 nm for random P3a to 915 nm of regular P1a, and that of P2a lies in-between. Comparing the solution and film spectra, an approximate 50 nm bathochromic shift is observed when transitioning from solution to film, which could be attributed to the polymer interchain self-aggregation. P1b, P2b and P3b with C16 side chains displayed 20-30 nm shift ( FIG. 4 ) to low energy wavelength, such shift could be attributed to the higher molecular weight and longer conjugation along polymer backbones. The optical band-gaps determined from the onset of film absorption were in range of 1.09-1.17 eV for all polymers (Table 3).
[0000]
TABLE 3
Photophysical properties of polymers
in solution a
films b
λ onset
λ max
λ onset
E g opt c
Polymer
λ max (nm)
(nm)
(nm)
(nm)
(eV)
P1a
915
1078
905
1112
1.12
P2a
835
1063
864
1085
1.14
P3a
825
1040
840
1060
1.17
P1b
930
1128
920
1140
1.09
P2b
885
1078
885
1108
1.12
P3b
880
1074
870
1076
1.15
a In o-dichlorobenzene solution.
b films were spin-coated from o-dichlorobenzene solution.
c Measurements performed on spin-coated films from the onset of the absorption band.
[0070] Heating the o-DCB solutions to 110° C. did not distinctly change the absorption profile of the ordered P1a and P2a. However, the random P3a exhibited a 30 nm blue-shift with respect to the 25° C. solution ( FIG. 4 ), possibly indicating the breakup of the aggregates at this temperature. Moreover, the absorption profiles after thermal annealing the films at 110° C. for 15 min. are very similar to the as casted films for all resulted polymers, with no distinct phase transition up to 300° C. by differential scanning calorimetry (DSC) measurement for all polymers ( FIG. 5 ), which might indicate the weak interchain π-π stacking in films.
[0071] The electrochemical properties of all polymers were investigated to gain insight into the affect of polymeric structure on the frontier molecular orbitals. Full details on the cyclic voltammetry (CV) measurements can be found in the supporting information in Example 2 ( FIG. 6 and Table 9).
[0072] From the data presented in Table 4, it is clear the regioregularity of polymer backbone has minimal affect on the lowest unoccupied molecular orbital (LUMO) level, while the highest occupied molecular orbital (HOMO) level energy is decreased with decreasing backbone order. The increase of the electrochemical band-gap of the random P3a and P3b compared to P2 and P1, again implies less effective charge localization along the polymer backbone. The larger electrochemical band-gap in comparison to the optical band gap could be attributed to the interfacial barrier for charge injection during the CV measurements.
[0000]
TABLE 4
GPC, CV and optical band-gap data of polymers
M n a /
E HOMO b /
E LUMO b /
E g cv c /
E g opt d /
Polymer
kDa
PDI
eV
eV
eV
eV
P1a
15.4
1.84
−5.12
−3.70
1.42
1.12
P1b
28.1
1.93
−5.10
−3.71
1.39
1.09
P2a
27.2
2.60
−5.16
−3.69
1.47
1.14
P2b
55.9
4.15
−5.16
−3.65
1.51
1.12
P3a
20.0
2.21
−5.23
−3.64
1.59
1.17
P3b
40.2
2.50
−5.22
−3.68
1.54
1.15
a Determined by GPC (150° C. in 1,2,4-trichlorobenzene).
b Calculated from the onsets of oxidation and reduction peaks, respectively.
c Calculated as the difference of the onset of the oxidation and reduction.
d Measurements performed on spin-coated films from the onset of the absorption band.
[0073] Next, the impact of the backbone structure on the charge carrier mobility was investigated. Considering that the low-lying LUMO energy level of polymer will improve electron injection and allow for effective electron transport, ambipolar OFETs based on these polymers were investigated as shown in FIG. 3 . Bottom gate, top contact FETs with structure of Si/SiO 2 /passivation layer/polymer (P1a, P2a or P3a)/Ag were fabricated by spin-coating from polymer solution on a highly n-doped silicon wafer with 200 nm of thermally-grown SiO 2 gate dielectrics passivated by PPCB or OTS-8. ( FIGS. 7 and 8 ). Distinct ambipolar characteristics were found at various thermal annealing temperatures. It is noticeable that both P1a and P2a exhibit higher charge mobility than that of the random copolymer P3a (Table 5).
[0000]
TABLE 5
FET mobility (cm 2 V −1 s −1 ) of polymers with Ag electrode
25° C.
90° C.
130° C.
Polymer
μ hole /μ electron
μ hole /μ electron
μ hole /μ electron
P1a a
5.6 × 10 −3 /2.7 × 10 −2
1.2 × 10 −4 /4.9 × 10 −3
2.2 × 10 −2 /1.2 × 10 −1
P1a b
4.8 × 10 −2 /2.4 × 10 −3
4.9 × 10 −2 /1.2 × 10 −3
3.5 × 10 −2 /1.6 × 10 −3
P2a a
1.0 × 10 −2 /3.4 × 10 −3
7.7 × 10 −3 /1.4 × 10 −2
1.7 × 10 −2 /9.7 × 10 −2
P2a b
6.4 × 10 −2 /2.0 × 10 −2
6.3 × 10 −2 /5.3 × 10 −3
9.4 × 10 −2 /3.1 × 10 −3
P3a a
1.6 × 10 −4 /2.8 × 10 −3
1.9 × 10 −4 /4.9 × 10 −3
2.2 × 10 −4 /8.3 × 10 −3
P3a b
6.3 × 10 −5 /2.1 × 10 −4
4.7 × 10 −5 /4.4 × 10 −5
4.5 × 10 −5 /3.8 × 10 −6
a FET device with PPCB as passivation layer;
b OTS-8 as passivation layer
[0074] The strongly dependent of mobility of P1a on the annealing temperature was found. The best efficiency was obtained after thermal annealing of the device at 130° C., and the hole and electron mobility passivated by PPCB amounts to 2.2×10 −2 and 1.2×10 −1 cm 2 V −1 s −1 , respectively, which is much higher than that from as-cast films (Table 6). Moreover, for FET based on P2a with OTS-8 passivation layer, the device also shows evident ambipolar behavior, exhibiting a hole and electron mobility of 9.4×10 −2 and 3.1×10 −3 cm 2 V −1 s −1 upon PPCB passivation, which is also much higher than that of the random P3a (Table 7). The distinct improvement of charge carrier mobility might be attributed to a more uniform orientation of the polymer chains in the solid-state.
[0000]
TABLE 6
PPCB passivation hole mobility/electron mobility (cm 2 V −1 s −1 )
Polymer
25° C.
90° C.
110° C.
130° C.
150° C.
P1a
5.6 × 10 −3 /
1.2 × 10 −4 /
1.0 × 10 −4 /
2.2 × 10 −2 /
1.9 × 10 −2 /
2.7 × 10 −2
4.9 × 10 −3
7.0 × 10 −3
1.2 × 10 −1
9.6 × 10 −2
P2a
1.0 × 10 −2 /
7.7 × 10 −3 /
9.8 × 10 −3 /
1.7 × 10 −2 /
1.4 × 10 −2 /
3.4 × 10 −3
1.4 × 10 −2
5.1 × 10 −2
9.7 × 10 −2
7.3 × 10 −2
P3a
1.6 × 10 −4 /
1.9 × 10 −4 /
1.0 × 10 −4 /
2.2 × 10 −4 /
1.9 × 10 −4 /
2.8 × 10 −3
4.9 × 10 −3
7.0 × 10 −3
8.3 × 10 −3
1.3 × 10 −2
[0000]
TABLE 7
OTS-8 passivation hole mobility/electron mobility (cm 2 V −1 s −1 )
Polymer
25° C.
90° C.
110° C.
130° C.
150° C.
P1a
4.8 × 10 −2 /
4.9 × 10 −2 /
4.5 × 10 −2 /
3.5 × 10 −2 /
4.5 × 10 −2 /
2.4 × 10 −3
1.2 × 10 −3
2.0 × 10 −3
1.6 × 10 −3
1.6 × 10 −3
P2a
6.4 × 10 −2 /
6.3 × 10 −2 /
6.2 × 10 −2 /
9.4 × 10 −2 /
8.8 × 10 −2 /
2.0 × 10 −2
5.3 × 10 −3
1.4 × 10 −3
3.1 × 10 −3
1.1 × 10 −3
P3a
6.3 × 10 −5 /
4.7 × 10 −5 /
3.2 × 10 −5 /
4.5 × 10 −5 /
7.1 × 10 −5 /
2.1 × 10 −4
4.4 × 10 −5
3.7 × 10 −5
3.8 × 10 −6
3.3 × 10 −6
[0075] The on/off ratio of the top contact device with silver electrode is approximately 500. In order to achieve a higher on/off ratio, gold with a deeper work function was selected as electrode and moreover, bottom gate, and bottom contact FETs were fabricated based on polymers with C16 side chain ( FIG. 9 ). It was found that after thermal annealing at 110° C. for 10 min, the hole mobility reached 0.15 and 0.14 cm 2 V −1 s −1 for P1b and P2b, respectively, which are much higher than the 0.025 cm 2 V −1 s −1 obtained by random copolymer P3b. The current on/off ratios for all FETs are improved to ˜10 4 for all devices (Table 8).
[0000]
TABLE 8
Temperature-dependent FET hole mobilities obtained from saturation
regime (μ hole , cm 2 V −1 s −1 ), and current on/off ratios (I on :I off ) for polymers on
Mitsubishi bottom-contact substrate, no passivation layer, 20 μm channel length.
25° C.
90° C.
110° C.
Polymer
μ hole
I on :I off
μ hole
I on :I off
μ hole
I on :I off
P1b
1.2 × 10 −2
4.0 × 10 3
9.3 × 10 −3
3.7 × 10 4
1.5 × 10 −1
1.0 × 10 4
P2b
1.3 × 10 −2
5.0 × 10 4
1.7 × 10 −2
3.2 × 10 4
1.4 × 10 −1
3.8 × 10 4
P3b
2.6 × 10 −3
1.2 × 10 4
1.5 × 10 −3
6.0 × 10 3
2.5 × 10 −2
4.0 × 10 4
* The devices were post-annealed.
[0076] In summary, CDT and PT based narrow band-gap polymers with well-ordered main chain were prepared by precisely controlled regioselective chemistry. The resulted copolymers with regioregular structures show much longer conjugation length and better charge localization along the polymer backbone. The low-lying LUMO energy levels were realized for all polymers with the strong electron PT as acceptor, which resulted in the emergence of ambipolar properties for OFET devices. It was found that the regioregular polymers show much higher mobilities than the random copolymers under different OFET device configurations.
Example 2
Instruments
[0077] Nuclear magnetic resonance (NMR) spectra were obtained on Bruker Avance DMX500 MHz spectrometer. Microwave assisted polymerizations were performed in a Biotage Initiator TM microwave reactor. Gel permeation chromatography (135° C. in 1,2,4-trichlorobenzene) was performed on a Polymer Laboratories PL220 Chromatograph. Differential scanning calorimetry (DSC) was determined by a TA Instruments DSC (Model Q-20) with about 5 mg polymers samples at a rate of 10° C./min in the temperature range of −20 to 300° C. UV-Vis absorption spectra were recorded on a Shimadzu UV-2401 PC dual beam spectrometer. Cyclic voltammetry (CVs) measurements were conducted using a standard three-electrode configuration under an argon atmosphere. A three-electrode cell equipped with a glassy carbon working electrode, a Ag wire reference electrode, and a Pt wire counterelectrode was employed. The measurements were performed in absolute acetonitrile with tetrabutylammonium hexafluorophosphate (0.1 M) as the supporting electrolyte at a scan rate of 50-100 mV/s. Polymer films were drop-cast onto the glassy carbon working electrode from a 2 mg/ml chloroform solution. The ferrocene/ferrocenium (Fc/Fc + ) redox couple was used as an internal reference (see FIG. 6 and Table 9).
[0000]
TABLE 9
CV data of polymers
E HOMO f /
E LUMO f
E g e
Polymer
E onset a /V
E 1/2 b /V
eV
E onset c /V
E 1/2 d /V
[eV]
[eV]
P1a
0.32
0.62
−5.12
−1.10
−1.36
−3.70
1.42
P2a
0.36
0.63
−5.16
−1.11
−1.33
−3.69
1.47
P3a
0.43
0.65
−5.23
−1.16
−1.36
−3.64
1.59
P1b
0.30
0.67
−5.10
−1.09
−1.38
−3.71
1.39
P2b
0.36
0.70
−5.16
−1.15
−1.38
−3.65
1.51
P3b
0.42
0.81
−5.22
−1.12
−1.32
−3.68
1.54
a the oxidation onset potential;
b the oxidation redox potential E 1/2 = (E pa + E pc )/2;
c the reduction onset potential;
d the reduction redox potential E 1/2 = (E pa + E pc )/2;
e the band-gap was calculated by the difference between the onset of oxidation and reduction potential;
f E HOMO = −e(E ox + 4.80) (eV), E LUMO = −e(E red + 4.80) (eV), the potential of Ag reference calibrated by Fc/Fc + .
Materials
[0078] 4H-Cyclopenta[2,1-b:3,4-b′]dithiophene (CDT) was purchased from WuXi AppTec Corporation. Toluene, THF and xylenes were purified according to standard procedures and distilled under nitrogen before use.
Synthesis of Monomers
(4,4-Didodecyl-4H-cyclopenta[1,2-b:5,4-b′]dithiophene-2,6-diyl)bis(tributylstannane) (1a)
[0079] A dry three-neck round bottom flask was equipped with a Schlenk adapter, dropping funnel, and rubber septum. Under nitrogen, 4,4-didodecyl-4H-cyclopenta[1,2-b:5,4-b]dithiophene (0.51 g, 1 mmol) was dissolved in dry THF (12 ml) and cooled −78° C. using a dry ice/acetone cold bath. Under nitrogen, a solution of t-butyllithium (1.7 M in pentane, 1.25 ml, 2.1 mmol) was added dropwise over 15 minutes to the reaction vessel. The reaction was stirred at −78° C. under nitrogen for one hour and at 25° C. for 5 hours. Then tributyltin chloride (0.81 g, 2.5 mmol) was added dropwise over 5 minutes to the reaction vessel via syringe at −78° C. The reaction was stirred at −78° C. under nitrogen for 1 hour and subsequently warmed to room temperature and stirred overnight. The mixture was then poured into deionized water (3×100 ml) and the organic phase was extracted with hexanes (3×100 ml). The organic phases were collected and washed with deionized water (5×100 ml), dried over sodium sulphate, filtered, and concentrated. The crude product was purified by flash column chromatography (Silica should be pretreated with 10 v/v % triethylamine/hexane solution) and dried under high vacuum to give 1.04 g of final product as yellowish oil, yield 95%. 1 H NMR (500 MHz, CDCl 3 ) δ (ppm): 6.93 (s, 2H), 1.81-1.78 (m, 4H), 1.61-1.56 (m, 12H), 1.36-1.08 (m, 60H), 0.98-0.75 (m, 281-1).
(4,4-Dihexadecyl-4H-cyclopenta[1,2-b:5,4-b′]dithiophene-2,6-diyl)bis(tributylstannane) (1b)
[0080] A dry three-neck round bottom flask was equipped with a Schlenk adapter, dropping funnel, and rubber septum. Under nitrogen, 4,4-didodecyl-4H-cyclopenta[1,2-b:5,4-b]dithiophene (0.63 g, 1 mmol) was dissolved in dry THF (12 ml) and cooled −78° C. using a dry ice/acetone cold bath. Under nitrogen, a solution of t-butyllithium (1.7 M in pentane, 1.25 ml, 2.1 mmol) was added dropwise over 15 minutes to the reaction vessel. The reaction was stirred at −78° C. under nitrogen for one hour and at 25° C. for 5 hours. Then tributyltin chloride (0.81 g, 2.5 mmol) was added dropwise over 5 minutes to the reaction vessel via syringe at −78° C. The reaction was stirred at −78° C. under nitrogen for 1 hour and subsequently warmed to room temperature and stirred overnight. The mixture was then poured into deionized water (3×100 ml) and the organic phase was extracted with hexanes (3×100 ml). The organic phases were collected and washed with deionized water (5×100 ml), dried over sodium sulphate, filtered, and concentrated. The crude product was purified by flash column chromatography (Silica should be pretreated with 10 v/v % triethylamine/hexane solution) and dried under high vacuum to give 1.14 g of final product as yellowish oil, yield 95%. 1 H NMR (500 MHz, CDCl 3 ) δ (ppm): 6.98 (s, 2H), 1.86 (m, 4H), 1.78-1.52 (m, 12H), 1.46-1.12 (m, 80H), 1.01-0.88 (m, 24H). 13 C NMR (125 MHz, CDCl 3 ) (ppm): 158.34, 140.37, 133.89, 127.78, 50.13, 35.90, 32.76, 30.02, 29.68, 28.20, 27.80, 27.75, 27.55, 27.46, 27.18, 27.09, 27.00, 25.94, 25.52, 25.33, 25.30, 25.07, 24.94, 23.37, 22.76.
7-Bromo-4-(4,4-didodecyl-6-(tributylstannyl)-4H-cyclopenta[1,2-b:5,4-b′]dithiophen-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine (2a)
[0081] To a solution of 4,7-dibromo-pyridal[2,1,3]thiadiazole (0.28 g, 0.95 mmol) and 1a (1.04 g, 0.95 mmol) in freshly distilled toluene (10 ml) was added Pd(PPh 3 ) 4 (109.8 mg, 0.095 mmol) under nitrogen, and then capped with a rubber septum. The reaction mixture was stirred at 75° C. for 10 hours. The solvent was removed and purified by column chromatography (silica was pretreated by 10 v/v % triethylamine/hexane solution) with hexane as eluent. The column separation was repeated for 3 times to give 0.31 g of viscous purple oil, yield 30%. 1 H NMR (500 MHz, CD 2 Cl 2 ) δ (ppm): 8.55 (s, 1H), 8.53 (s, 1H), 7.01 (s, 1H), 1.95-1.91 (m, 4H), 1.63-1.56 (m, 6H), 1.37-1.31 (m, 6H), 1.26-1.12 (m, 42H), 1.08-0.97 (m, 4H), 0.91-0.82 (m, 15H); 13 C NMR (CDCl 3 , 125 MHz) δ (ppm): 163.11, 160.01, 156.33, 148.10, 147.92, 145.92, 143.99, 142.26, 141.81, 140.27, 129.80, 127.62, 106.17, 37.85, 31.88, 29.96, 29.61, 29.52, 29.34, 29.31, 28.98, 27.21, 24.57, 22.66, 13.85, 13.44, 10.95.
7-Bromo-4-(4,4-dihexadecyl-6-(tributylstannyl)-4H-cyclopenta[1,2-b:5,4-b′]dithiophen-2-yl)-[1,2,5]thiadiazolo[3,4-c]pyridine (2b)
[0082] To a solution of 4,7-dibromo-pyridal[2,1,3]thiadiazole (0.28 g, 0.95 mmol) and 1b (1.14 g, 0.95 mmol) in freshly distilled toluene (10 ml) was added Pd(PPh 3 ) 4 (109.8 mg, 0.095 mmol) under nitrogen, and then capped with a rubber septum. The reaction mixture was stirred at 75° C. for 10 hours. The solvent was removed and purified by column chromatography (silica was pretreated by 10 v/v % triethylamine/hexane solution) with hexane as eluent. The column separation was run for 3 times to give 268 mg of viscous purple oil, with yield of 25%. 1 H NMR (500 MHz, CDCl 3 ) δ (ppm): 8.92 (s, 1H), 8.49 (s, 1H), 7.39 (s, 1H), 2.21 (m, 4H), 1.77 (m, 6H), 1.54-1.25 (m, 68H), 1.12-1.01 (m, 15H). 13 C NMR (125 MHz, CD 2 Cl 2 ) δ (ppm): 163.10, 160.00, 156.32, 148.09, 147.92, 145.93, 144.00, 142.24, 141.83, 140.28, 129.79, 127.62, 106.17, 53.53, 37.86, 31.92, 29.97, 29.66, 29.63, 29.59, 29.54, 29.42, 29.39, 29.35, 29.32, 29.29, 29.02, 28.99, 27.21, 24.58, 22.69, 22.65, 13.88, 13.45, 10.96.
4,4′-(4,4-Didodecyl-4H-cyclopenta[1,2-b:5,4-H]dithiophene-2,6-diyl)bis(7-bromo-[1,2,5]thiadiazolo[3,4-c]pyridine) (3a)
[0083] To a solution of 4,7-dibromo-pyridal[2,1,3]thiadiazole (0.22 g, 0.75 mmol) and 1a (0.27 g, 0.25 mmol) in freshly distilled toluene (10 ml) was added Pd(PPh 3 ) 4 (28.9 mg, 0.025 mmol) under nitrogen. The reaction mixture was stirred at 75° C. for 48 hours. Then the solvent was removed and the mixture was purified by column chromatography with chloroform/hexane (from 0 to 60 v/v %). Then the crude product was precipitated from dichloromethane and methanol to give 0.17 mg of purple oil, yield 72%. 1 H NMR (500 MHz, CDCl 3 ) δ (ppm): 8.63 (s, 2H), 8.57 (s, 2H), 2.06-2.03 (m, 4H), 1.26-1.13 (m, 40H), 1.09 (t, J=4.0 Hz, 6H); 13 C NMR (125 MHz, CD 2 Cl 2 ) δ (ppm): 162.05, 156.40, 147.88, 147.69, 146.03, 143.60, 143.09, 126.80, 107.39, 54.63, 37.83, 31.87, 29.96, 29.63, 29.59, 29.56, 29.52, 29.34, 29.31, 24.66, 22.66, 14.10.
4,4′-(4,4-Dihexadecyl-4H-cyclopenta[1,2-b:5,4-b]dithiophene-2,6-diyl)bis(7-bromo-[1,2,5]thiadiazolo[3,4-c]pyridine) (3b)
[0084] To a solution of 4,7-dibromo-pyridal[2,1,3]thiadiazole (0.44 g, 1.5 mmol) and 1b (0.60 g, 0.5 mmol) in freshly distilled toluene (10 ml) was added Pd(PPh 3 ) 4 (57.8 mg, 0.05 mmol) under nitrogen. The reaction mixture was stirred at 75° C. for 48 hours. Then the solvent was removed and the mixture was purified by column chromatography with chloroform/hexane (from 0 to 60 v/v %). Then the crude product was precipitated from dichloromethane and methanol to give 280 mg of purple solid, yield 53%. 1 H NMR (500 MHz, CDCl 3 ) δ (ppm): 8.66 (s, 2H), 8.59 (s, 2H), 2.07 (m, 4H), 2.07 (m, 4H), 1.32-1.08 (m, 56H), 0.89 (t, J=6.70 Hz, 6H). 13 C NMR (125 MHz, CD 2 Cl 2 ) δ (ppm): 162.04, 156.34, 147.81, 147.59, 145.96, 143.59, 143.13, 126.79, 107.34, 54.60, 37.80, 31.92, 30.04, 29.65, 29.60, 29.35, 24.73, 22.69, 14.13.
(4,4-Didodecyl-4H-cyclopenta[1,2-b:5,4-b′]dithiophene-2,6-diyl)bis(trimethylstannane) (4a)
[0085] A dry three-neck round bottom flask was equipped with a Schlenk adapter, dropping funnel, and rubber septum. Under nitrogen, 4,4-didodecyl-4H-cyclopenta[1,2-b:5,4-b′]dithiophene (0.51 g, 1 mmol) was dissolved in dry THF (12 ml) and cooled −78° C. using a dry ice/acetone cold bath. Under nitrogen, a solution of t-butyllithium (1.7 M in pentane, 2.35 ml, 4 mmol) was added dropwise over 15 minutes to the reaction vessel. The reaction was stirred at −78° C. under nitrogen for one hour and stirred at room temperature for 3 hours. Under nitrogen, a solution of trimethyltin chloride (1.0 g, 5 mmol) in dry pentane (2 ml) was added dropwise over 5 minutes to the reaction vessel at −78° C. The reaction was stirred at −78° C. under nitrogen for 1 hour and subsequently warmed to room temperature and stirred overnight. The mixture was then poured into deionized water (3×100 ml) and the organic phase extracted with hexanes (3×50 ml). The organic phases were collected and washed with deionized water (3×50 ml), dried over sodium sulphate, filtered, and concentrated. The product was dried under high vacuum with agitation for 48 hours to give 0.80 g of product as colorless oil, yield 95%. 1 H NMR (500 MHz, CD 2 Cl 2 ) δ (ppm): 6.94 (s, 2H), 1.79-1.76 (m, 4H), 1.29-1.15 (m, 36H), 1.08-1.02 (m, 4H), 0.88 (t, J=6.0 Hz, 6H), 0.39 (s, 18H).
(4,4-Dihexadecyl-4H-cyclopenta[1,2-b:5,4-b′]dithiophene-2,6-diyl)bis(trimethylstannane) (4b)
[0086] A dry three-neck round bottom flask was equipped with a Schlenk adapter, dropping funnel, and rubber septum. Under nitrogen, 4,4-didodecyl-4H-cyclopenta[1,2-b:5,4-b]dithiophene (0.63 g, 1 mmol) was dissolved in dry THF (12 ml) and cooled −78° C. using a dry ice/acetone cold bath. Under nitrogen, a solution of t-butyllithium (1.7 M in pentane, 2.35 ml, 4 mmol) was added dropwise over 15 minutes to the reaction vessel. The reaction was stirred at −78° C. under nitrogen for one hour and stirred at room temperature for 3 hours. Under nitrogen, a solution of trimethyltin chloride (1.0 g, 5 mmol) in dry pentane (2 ml) was added dropwise over 5 minutes to the reaction vessel at −78° C. The reaction was stirred at −78° C. under nitrogen for 1 hour and subsequently warmed to room temperature and stirred overnight. The mixture was then poured into deionized water (3×100 ml) and the organic phase extracted with hexanes (3×50 ml). The organic phases were collected and washed with deionized water (3×50 ml), dried over sodium sulphate, filtered, and concentrated. The product was dried under high vacuum with agitation for 48 hours to give 0.92 g of white solid, yield 97%. 1 H NMR (500 MHz, CD 2 Cl 2 ) δ (ppm): 7.03 (s, 2H), 1.85 (m, 4H), 1.46-1.18 (m, 52H), 1.04 (m, 4H), 0.92 (t, J=6.65 Hz, 6H), 0.42 (t, 18H). 13 C NMR (125 MHz, CD 2 Cl 2 ) δ (ppm): 160.57, 142.11, 137.21, 129.58, 52.21, 37.62, 34.63, 34.57, 31.97, 31.94, 31.59, 30.03, 29.69, 29.63, 29.59, 29.36, 25.24, 24.63, 22.66, 20.42, 13.88.
Polymerization of P1a
[0087] Monomer 2a (0.16 g, 0.16 mmol) was carefully weighed and added to a 2-5 mL microwave tube. The tube was transferred into a glovebox, and then Pd(PPh 3 ) 4 (4.4 mg, 0.005 mmol), and 3.2 mL of xylenes were added into the microwave tube. The tube was sealed, removed from the glovebox and subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 120° C. for 2 min, 160° C. for 2 min and 200° C. for 40 min. The reaction was allowed to cool leaving a viscous liquid containing some solid material. After the polymerization, 2-bromothiophene (1.9 μl 0.02 mmol) and 2 mL of xylenes was added, the mixture was stirred at 110° C. for 2 hours. And then tributyl(thiophen-2-yl)stannane (0.01 mL, 0.04 mmol) was added dropwise and stirred at 110° C. for 2 hours. Then the mixture was dissolved in hot 1,2-dichlorobenzene, then precipitated into methanol and collected via centrifugation. The residual solid was loaded into a cellulose extraction thimble and washed successively with methanol (3 hrs), hexanes (16 hrs), and acetone (3 hrs). The remaining polymer was dried on a high vacuum line overnight. Yield 92 mg (88%). 1 H NMR (500 MHz, C 2 D 2 Cl 4 , 110° C.) δ (ppm): 9.00 (s, 1H), 8.67 (s, 1H), 8.14 (s, 1H), 2.30-0.76 (m, 50H). 13 C NMR (Solid-state, 75 MHz), δ (ppm): 159.57, 151.45, 145.77, 142.29, 138.67, 124.42, 116.17, 113.81, 52.57, 36.06, 29.83, 25.53, 22.61, 13.84.
Polymerization of P1b
[0088] Monomer 2b (128 mg, 0.11 mmol) and Pd 2 (dba) 3 (5.2 mg, 0.0057 mmol), P(o-Tol) 3 (6.9 mg, 0.023 mmol) and freshly distilled xylenes (4 ml) was added to a 2-5 ml microwave tube under nitrogen. The mixture was heated to 95° C. on the oil bath and stirred for 12 hours. After that, tributyl(thiophen-2-yl)stannane (20 μl) was added and the reaction was stirred at 95° C. for 6 hours, then 2-bromothiophene (20 μl) was added and the reaction was stirred for another 6 hours. The mixture was precipitated in methanol, the resulted dark green fibers were collected and was re-dissolved in hot 1,2-dichlorobenzene. Then re-precipitated in methanol and collected via centrifugation. The collected solid fibers were loaded into a cellulose extraction thimble and washed successively with methanol (6 hours), acetone (6 hours), hexanes (12 hours) and chloroform (24 hours). The solid residue in the thimble was collected and dried followed by re-dissolved in hot 1,2-dichlorobenzene, filtrated and re-precipitated in methanol. Then the resulted dark-green fibers were collected via centrifugation, dried over high vacuum line to give 61 mg of polymers, yield 80%. 1 H NMR (500 MHz, C 2 D 2 Cl 4 , 110° C.) δ (ppm): 8.99 (s, 11-f), 8.67 (s, 1H), 8.14 (s, 1H), 2.26-0.82 (m, 66H).
Polymerization of P2a
[0089] The polymer was prepared following a previously reported microwave assisted polymerization technique. Two monomers 3a (0.18 g, 0.19 mmol) and 4a (0.17 g, 0.20 mmol) were carefully weighed and added to a 2-5 mL microwave tube. The tube was transferred into a glovebox, and then Pd(PPh 3 ) 4 (9 mg, 0.008 mmol) and 3 mL of Xylenes were added into the microwave tube. The tube was sealed, removed from the glovebox and subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 120° C. for 2 min, 160° C. for 2 min and 200° C. for 40 min. The reaction was allowed to cool leaving a viscous liquid containing some solid material. After the polymerization, 2-bromothiophene (1.9 μl, 0.02 mmol) and 2 mL of xylenes was added, the mixture was stirred at 110° C. for 2 hours. And then tributyl(thiophen-2-yl)stannane (0.01 mL, 0.04 mmol) was added dropwise and stirred at 110° C. for 2 hours. The mixture was dissolved in hot 1,2-dichlorobenzene, then precipitated into methanol and collected via centrifugation. The residual solid was loaded into a cellulose extraction thimble and washed successively with methanol (4 hrs), hexanes (16 hrs), and acetone (3 hrs). The remaining polymer was dried on a high vacuum line overnight. Yield 225 mg (91%). 1 H NMR (500 MHz, C 2 D 2 Cl 4 , 110° C.) δ (ppm): 8.99 (s, 1H), 8.67 (s, 1H), 8.16 (s, 1H), 2.30-0.72 (m, 50H). 13 C NMR (Solid-state, 75 MHz) δ (ppm): 158.76, 151.90, 143.27, 138.063, 123.15, 117.44, 52.74, 36.06, 29.75, 25.53, 22.55, 13.78.
Polymerization of P2b
[0090] Monomers 3b (158.3 mg, 0.15 mmol) and 4b (142.9 mg, 0.15 mmol) were added to a 2-5 mL microwave tube, then Pd(PPh 3 ) 4 (8.7 mg, 0.0075 mmol) and freshly distilled xylenes (4 ml) were added into the microwave tube. The tube was sealed and subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 40 min. The reaction was allowed to cool to room temperature, then tributyl(thiophen-2-yl)stannane (20 μl) was added and the reaction was subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 20 min. After the reaction was cooled to room temperature, 2-bromothiophene (20 μl) was added and the end-capping procedure was repeated once again. The mixture was precipitated in methanol, collected via centrifugation. The collected solid fibers were loaded into a cellulose extraction thimble and washed successively with methanol (6 hours), acetone (6 hours), hexanes (12 hours), and the polymer comes out with chloroform (within 2 hours) from the thimble. Chloroform was removed under reduced pressure and resulted dark-green solid was dried over high vacuum line to give 130 mg of polymer, yield 85%. 1 H NMR (500 MHz, C 2 D 2 Cl 4 , 110° C.) δ (ppm): 8.99 (s, 1H), 8.67 (s, 1H), 8.16 (s, 1H), 2.30-0.81 (m, 66H).
Polymerization of P3a
[0091] The polymerization was performed following the procedure for P2a in microwave reactor, just replacing monomer 3a by 4,7-dibromo-pyridal[2,1,3]thiadiazole (44.2 mg, 0.15 mmole). The resulted dark-green solid was dried over high vacuum line to give 91 mg of polymer, yield 80%. 1 H NMR (500 MHz, C 2 D 2 Cl 4 , 110° C.) δ (ppm): 8.99 (s, 1H), 8.67 (s, 1H), 8.15 (s, 1H), 2.32-0.79 (m, 50H). 13 C NMR (Solid-state, 75 MHz) δ (ppm): 159.04, 152.06, 142.95, 138.39, 124.16, 117.54, 52.87, 36.01, 29.72, 25.67, 22.53, 13.76.
Polymerization of P3b
[0092] The polymerization was performed following the procedure for P2b in microwave reactor, just replacing monomer 3b by 4,7-dibromo-pyridal[2,1,3]thiadiazole (44.2 mg, 0.15 mmole). The resulted dark-green solid was dried over high vacuum line to give 101 mg of polymer, yield 86%. 1 H NMR (500 MHz, C 2 D 2 Cl 4 , 110° C.) δ (ppm): 8.99 (s, 1H), 8.67 (s, 1H), 8.15 (s, 1H), 2.35-0.84 (m, 66H).
Example 3A
[0093] To apply the regioregular PT based copolymer in an OPV device, we chose indacene-PT based copolymers due to (1) the broad narrow-bandgap absorption, (2) the two thiophene rings rigidified together with a central phenyl ring, which can provide strong intermolecular interactions for ordered packing to improve the charge carrier mobility, and (3) the low-lying HOMO level of the copolymer will provide high open-circuit voltage (V oc ) (see Jen et al. [11])
Result and Discussion
[0094] As shown in Scheme 4, the copolymerization of dibromo monomer Br-PT-IDT-PT-Br (M2) with bis(stannyl) monomer Me 3 Sn-IDT-SnMe 3 (M1) was based on microwave assisted Stille coupling reaction to generate the regioregular indacenothiophene-PT based copolymer (PIPT-RG), which has the N-atom in the PT units selectively faced to the same indacene core. The reference polymer (PIPT-RA) was synthesized based on microwave assisted step-growth Stille copolymerization of M1 and 4,7-dibromo-pyridal[2,1,3]thiadiazole (PTBr 2 ), thus providing the polymer with the N-atom in the PT units randomly distributed along the polymer main chain. Both copolymers were purified by Soxhlet extraction using methanol, acetone, hexane and finally collected by chloroform. The polymer structures are shown in Scheme 5.
[0000]
[0000]
[0095] The number average molecular weight (M n ) estimated by gel permeation chromatography (GPC) with chloroform as eluent and linear polystyrene as the reference at 35° C. is 68 kDa (PDI=2.4) for PIPT-RG and 59 kDa (PDI=2.5) for PIPT-RA; the GPC profiles are shown in FIG. 10 . In contrast, GPC in 1,2,4-trichlorobenze (1,2,4-TCB) as eluent at 150° C. gave 46 kDa and 42 kDa for PIPT-RG and PIPT-RA, with a polydispersity of 2.3 and 2.8, respectively. The slightly lower Mn can be attributed to less aggregation in high temperature 1,2,4-TCB solution. Interestingly, both copolymers exhibited excellent solubility of higher than 15 mg/ml in xylenes, chloroform, chlorobenzene as well as 1,2-dichlorobenzene, which provides the opportunity to fabricate thick films based solution process procedures. No noticeable phase transitions were observed by differential scanning calorimetry up to 300° C. in both cases ( FIG. 11 ).
[0096] UV-Vis absorption profiles of PIPT-RG and PIPT-RA in thin films are shown in FIG. 12 . The absorption profile shapes are essentially the same for both copolymers. The short wavelength absorption bas (—417 nm) is assigned to a delocalized excitonic π-π* transition and the long wavelength absorption band (˜715 nm) is ascribed to intramolecular charge transfer (ICT) interactions between the donor and acceptor moieties. However, the absorption intensity of PIPT-RG is much stronger than that of PIPT-RA, indicating a much higher molar absorption coefficient of PIPT-RG. The optical band gaps (E g ) calculated from the absorption onset are determined to be 1.60 eV for PIPT-RG, which is slightly lower than that of 1.62 eV for PIPT-RA.
[0097] Cyclic voltammetry (CV) and ultraviolet photoelectron spectroscopy (UPS) were employed to evaluate the oxidation/reduction properties and electrical stability of the polymers. As can be seen in the CV curves in FIG. 13 a , the onset of reduction (E red ) of the two copolymers were nearly identical and was located at about −1.20 V versus Ag/Ag + , while the onset of oxidation (E ox ) were 0.45 V and 0.55 V for PIPT-RG and PIPT-RA, respectively. The slightly higher E ox of PIPT-RA to that of PIPT-RG might be attributed to the more disordered vector of the PT unit along the polymer main chain, which would disturb the π-conjugated electron distribution along the polymer backbone leading to a slightly raised E ox . The highest occupied molecular orbital energy level (E HOMO ) and the lowest unoccupied molecular orbital energy level (E LUMO ) were calculated from the E ox and E red , on the basis of the assumption that E HOMO of ferrocene/ferrocenium (Fc/Fc + ) is at 4.8 eV relative to vacuum. The calculated E HOMO are −5.25 eV and −5.35 eV for PIPT-RG and PIPT-RA, respectively, and the E LUMO are both at −3.60 eV. This is understandable since for such “donor-acceptor” based copolymers, the LUMO is mainly located in the acceptor and the HOMO is well-delocalized along the conjugated backbone, thus the two copolymers exhibited nearly identical E LUMO while slightly different E HOMO . Further evaluation by ultraviolet photoelectron spectroscopy (UPS) measurements ( FIG. 13 b ) demonstrated that the E HOMO of the two copolymers are quite similar, located at −5.31 eV and −5.33 eV for PIPT-RG and PIPT-RA, respectively, Nevertheless, the relatively low-lying E HOMO indicated that high V oc could be realized.
[0098] The field-effect hole mobilities of PIPT-RG and PIPT-RA were extracted from the transfer characteristics ( FIG. 14 ) of field-effect transistors (FETs) fabricated with bottom contact, bottom gate geometry using Au electrodes. It was noted that the calculated mobilities for PIPT-RG at room temperature of 0.13 cm 2 /Vs improved to 0.18 and 0.20 cm 2 /Vs after thermal annealing at 100° C. and 150° C. for 10 min, respectively. These are higher than for devices prepared under the same conditions with a PIPT-RA copolymer film of 0.04 cm 2 /Vs at room temperature, and 0.09 and 0.04 cm 2 /Vs attained after thermal annealing at 100° C. and 150° C. for 10 min, respectively. The higher carrier mobility achieved with regioregular PIPT-RG than the regiorandom counterpart PIPT-RA indicates that better charge transport in the active layer could be achieved. The detailed FET data were summarized in Table 10.
[0000]
TABLE 10
FET performances of bottom gate top-contact device structures
polymer
T anneal (° C.)
μ hole (cm 2 /Vs)
I on /I off
PIPT-RG
—
0.13
4 × 10 4
100
0.18
1 × 10 4
150
0.20
4 × 10 3
PIPT-RA
—
0.04
1 × 10 4
100
0.09
7 × 10 3
150
0.04
2 × 10 3
[0099] The microstructures of two copolymer films were investigated by grazing incident X-ray diffraction (XRD). The samples were prepared on the top of (n-decyl)trichlorosilane (DTS) treated silicon substrate according to the same procedure of FET devices. The films were thermally annealed at 100° C. for 10 min. As shown in FIG. 15 , the scattering features with two distinct peaks centered at q values of 0.42 Å −1 (spacing of 14.9 Å) and 1.42 Å −1 (spacing of 4.4 Å) were realized for both copolymers. However, more fine structures could be realized for the random copolymer PIPT-RA, which shows small bumpy scattering features with q values of 0.63 Å −1 (spacing of 9.9 Å) and 1.21 Å −1 (spacing of 5.2 Å). Such relatively weak scattering features might be attributed to the combination of various structures in random copolymers.
[0100] In considering that the copolymers were used as donor materials for bulk heterojunction solar cells, the contact of active layer with following deposited metal is of particular importance. The surface morphologies of copolymer:PC 71 BM (1:4 in wt:wt) films were studies by tapping-mode atomic force microscopy (AFM), and the films were spin-casted from copolymer:PC 71 BM solution on the top of ITO/MoOx layer and followed the optimized conditions for solar cell devices. Even though the solar cell devices based on PIPT-RG:PC 71 BM as active layer showed much higher power conversion efficiency (5.1%) than that of achieved by PIPT-RA:PC 71 BM device (3.4%), we noted that both films were quite smooth with root-mean-square (rms) value ˜0.3 nm ( FIG. 16 ).
[0101] To further understand the microstructure differences in both films, we used transmission electron microscopy (TEM) to investigate the microstructure inside both films. It was realized that both PIPT-RG:PC 71 BM ( FIG. 17 a ) and PIPT-RA:PC 71 BM ( FIG. 17 b ) films exhibited relatively uniform images. It should be noted that the dark spots with size of 10-20 nm in FIG. 17( a ) might be attributed to the metallic residue.
Example 3B
Materials and Methods for Example 3A
Instruments
[0102] Nuclear magnetic resonance (NMR) spectra were obtained on Bruker Avance DMX500 MHz spectrometer. Gel permeation chromatography (150° C. in 1,2,4-trichlorobenzene) was performed on a Polymer Laboratories PL220 Chromatograph. GPC with chloroform as eluent was performed in chloroform (with 0.25 v/v % triethylamine) on a Waters system, and the molecular weight of polymers were estimated relative to linear PS standards. Differential scanning calorimetry (DSC) was determined by a TA Instruments DSC (Model Q-20) with about 5 mg polymers samples at a rate of 10° C./min in the temperature range of −20 to 300° C. UV-Vis absorption spectra were recorded on a Shimadzu UV-2401 PC dual beam spectrometer. Cyclic voltammetry (CV) measurements were conducted using a standard three-electrode configuration under an argon atmosphere. A three-electrode cell equipped with a glassy carbon working electrode, a Ag wire reference electrode, and a Pt wire counterelectrode was employed. The measurements were performed in absolute acetonitrile with tetrabutylammonium hexafluorophosphate (0.1 M) as the supporting electrolyte at a scan rate of 50-100 mV/s. Polymer films for CV test were drop-casted onto the glassy carbon working electrode from a 2 mg/mL chloroform solution. The absolute energy level of ferrocene/ferrocenium (Fc/Fc + ) to be 4.8 eV below vacuum. Grazing incident X-ray diffraction was performed on Rigaku Smart instrument. Atomic force microscopy (AFM) was recorded on Asylum MFP3D instrument. All the samples were prepared identical to optimized device structure and conditions prior to electrode deposition. Transmission Electron Microscope (TEM) was performed on FEI Tecnai G2 Sphera Microscope instrument. The samples were prepared by spin-casting on the top of glass substrate and floated in water, following by put on the top of copper grid.
Synthesis of Monomers
(4,4,9,9-Tetrakis(4-hexylphenyl)-4,9-dihydro-s-indaceno[1,2-b′]dithiophene-2,7-diyl)bis(trimethylstannane) (M1)
[0103] A dry three-neck round bottom flask was equipped with a Schlenk adapter, dropping funnel, and rubber septum. Under nitrogen, 2,7-dibromo-4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene (1.06 g, 1 mmol) was dissolved in dry TI-IF (20 mL) and cooled −78° C. using a dry ice/acetone cold bath. Under nitrogen, a solution of n-butyllithium (1.6 M in hexane, 1.50 mL, 2.4 mmol) was added dropwise over 15 minutes to the reaction vessel. The reaction was stirred at −78° C. under nitrogen for one hour. Then trimethyltin chloride (0.60 g, 3.0 mmol) was added dropwise over 5 minutes to the reaction vessel via syringe at −78° C. The reaction was stirred at −78° C. under nitrogen for 1 hour and subsequently warmed to room temperature and stirred overnight. The mixture was then poured into deionized water (3×100 mL) and the organic phase was extracted with hexanes (3×100 mL). The organic phases were collected and washed with deionized water (5×100 mL), dried over sodium sulphate, filtered, and concentrated. The crude product was recrystallized from hexane/ethanol (10/90) and dried under high vacuum to give 1.07 g of final product as white needles, yield 87%. NMR (500 MHz, CDCl 3 ) δ (ppm): 7.48 (s, 2H), 7.21 (d, 8H), 7.13 (d, 8H), 2.63 (t, J=7.75 Hz, 8H), 1.66-1.57 (m, 8H), 1.42-1.30 (m, 24H), 0.89 (m, 12H), 0.41 (s, 18H). 13 C NMR (125 MHz, CD 2 Cl 2 ) δ (ppm): 157.64, 153.75, 147.14, 142.31, 141.90, 141.54, 134.71, 130.44, 128.35, 128.28, 127.81, 127.75, 117.65, 62.19, 35.48, 31.76, 31.66, 29.16, 22.64, 13.89, −8.39. HRMS (FD) m/z, calcd for Chemical Formula: C 70 H 90 S 2 Sn 2 (M + ): 1232.45. found: 1232.5.
4,4′-(4,4,9,9-Tetrakis(4-hexylphenyl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(7-bromo-[1,2,5]thiadiazolo[3,4-c]pyridine) (M2)
[0104] To a 10-20 mL microwave tube was added M1 (0.616 g, 0.5 mmol), 4,7-dibromo-pyridal[2,1,3]thiadiazole (0.295 g, 1 mmol), Pd(PPh 3 ) 4 (57.8 mg, 0.05 mmol) and freshly distilled toluene (10 mL) under the protection of nitrogen, then the microwave tube was sealed. The microwave assisted Stille coupling was performed in the following procedure: 120° C. for 10 min, 140° C. for 10 min, 160° C. for 10 min and 170° C. for 40 min. The reaction was cooled down to room temperature, extracted with chloroform (100 mL×3), washed with deionized water (100 mL×3) and dried over with anhydrous magnesium sulfate. After removing solvent under reduced pressure, the mixture was separated by silica column with hexane/chloroform (form 100/0 to 0/100 in v/v) to give 0.553 g of dark-red oil, yield of 83%. 1 H NMR (500 MHz, CDCl 3 ) δ (ppm): 8.64 (s, 2H), 8.60 (s, 2H), 7.65 (s, 2H), 7.31 (s, 8H), 7.16 (s, 8H), 2.61 (s, 8H), 1.63 (s, 8H), 1.45-1.26 (m, 24H), 0.90 (s, 121-1). 13 C NMR (125 MHz, CD 2 Cl 2 ) δ (ppm): 158.11, 156.29, 154.63, 147.74, 147.54, 147.38, 145.91, 143.86, 141.84, 141.37, 136.01, 128.69, 128.55, 127.95, 127.95, 118.61, 107.54, 63.27, 35.60, 31.73, 31.35, 29.17, 22.61, 14.11. HRMS (FD) m/z, calcd for C 74 H 74 Br 2 N 6 S 4 (M + ): 1334.32. found: 1334.3.
Polymerization of PIPT-RG
[0105] Monomer M1 (123.3 mg, 0.1 mmol), M2 (133.4 mg, 0.1 mmol), Pd(PPh 3 ) 4 (5.8 mg, 0.005 mmol) and freshly distilled xylenes (3 mL) was added to a 2-5 mL microwave tube under nitrogen. The tube was sealed and subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 120° C. for 2 min, 160° C. for 2 min and 180° C. for 40 min. The reaction was allowed to cool to room temperature, then freshly distilled xylenes (2 mL) and tributyl(thiophen-2-yl)stannane (20 μl) was added and the reaction was subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 20 min. After the reaction was cooled to room temperature, 2-bromothiophene (20 μl) was added and the reaction was subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 20 min. The mixture was precipitated in methanol, collected via centrifugation, then re-dissolved in hot 1,2-dichlorobenzene and re-precipitated in methanol and collected via centrifugation. The collected solid fibers were loaded into a cellulose extraction thimble and washed successively with methanol (12 hours), acetone (12 hours) and hexanes (12 hours), and then chloroform (2 hours) to collected the copolymer. The solid residue in the thimble was collected and dried followed by re-dissolved in hot 1,2-dichlorobenzene, filtrated and re-precipitated in methanol. Then the resulted dark-green fibers were collected via centrifugation, dried over high vacuum line to give 156 mg of polymers, yield 75%. GPC with chloroform as eluent showed the Mn=68 kDa (PDI=2.4). 1 H NMR (500 MHz, 1,2-dichlorobenzene-d 4 , 110° C.) δ (ppm): 8.90 (s, 1H), 8.84 (s, 1H), 8.40 (s, 1H), 8.12 (s, 1H), 8.04 (s, 1H), 7.80-7.50 (br s, 8H), 7.30-7.15 (br s, 8H), 2.70 (br s, 8H), 1.71 (s, 8H), 1.55-1.32 (m, 24H), 0.98 (s, 12H). 13 C NMR (125 MHz, 1,2-dichlorobenzene-d 4 , 110° C.) δ (ppm): 180.06, 169.02, 163.49, 157.70, 141.59, 132.15, 130.04, 129.84, 129.71, 129.63, 129.42, 127.32, 127.22, 127.12, 127.05, 126.95, 126.85, 126.75, 126.65, 126.40, 102.74, 63.62, 35.38, 31.49, 30.98, 30.79, 28.88, 22.31, 13.61.
Polymerization of PIPT-RA
[0106] The polymerization was performed following the procedure for PIPT-RG in microwave reactor. The monomer M1 (246.6 mg, 0.2 mmol), and replacing monomer M2 by 4,7-dibromo-pyridal[2,1,3]thiadiazole (59.0 mg, 0.2 mmol), Pd(PPh 3 ) 4 (11.5 mg, 0.01 mmol) and xylenes (3 mL). The resulted dark-green solid was dried over high vacuum line to give 168.5 mg of polymer, yield 81%. GPC with chloroform as eluent showed the Mn=59 kDa (PDI=2.5). 1 H NMR (500 MHz, 1,2-dichlorobenzene-d 4 , 110° C.) δ (ppm): 8.86 (s, 1H), 8.81 (s, 1H), 8.35 (s, 1H), 8.12 (s, 1H), 8.03 (s, 1H), 7.82-7.49 (br s, 8H), 7.36-7.18 (br s, 8H), 2.66 (br s, 8H), 1.70 (s, 8H), 1.52-1.38 (m, 24H), 0.92 (s, 121-1). 13 C NMR (125 MHz, 1,2-dichlorobenzene-d 4 , 110° C.) δ (ppm): 180.07, 169.03, 163.50, 157.99, 141.56, 132.19, 130.24, 129.94, 129.81, 129.80, 129.58, 127.45, 127.32, 127.22, 127.18, 127.06, 126.97, 126.86, 126.72, 126.51, 102.83, 63.84, 35.39, 32.38, 31.50, 29.10, 22.47, 13.74.
UPS Characterization
[0107] An Au film of 75 nm was deposited on a precleaned Si substrate with a thin native Oxide. A solution containing a mixture of PIPT-RA (or PIPT-RG):PC 71 BM (1:4) in ODCB solvent with a concentration of 2 mg/mL was then spin-casted atop the Au film. The total time of spin coating was kept at 60 s for the two samples. Film fabrication was done in a N 2 -atmosphere glove box. To minimize possible influence by exposure to air, the films were then transferred from the N 2 -atmosphere dry box to the analysis chamber inside an air-free sample holder. Subsequently, the samples were kept inside a high-vacuum chamber overnight, to remove solvent. The UPS analysis chamber was equipped with a hemispherical electron-energy analyzer (Kratos Ultra spectrometer), and was maintained at 1.33×10 −7 Pa. The UPS was measured using the He I (hv=21.1 eV) source, and he electron energy analyzer was operated at constant pass energy of 10 eV. During the measurements, a sample bias of −9 V was used in order to separate the sample and the secondary edge for the analyzer. In order to confirm reproducibility of UPS spectra, we repeated these measurements twice on two sets of samples.
FET Device Fabrication
[0108] Semiconducting polymers, 0.5 wt % PIPT-RG or PIPT-RA dissolved in chlorobenzene. The copolymers were stirring under 110° C. before usage. Heavily doped n-type silicon substrates with 200 nm thermally grown SiO 2 were prepared as bottom gate electrode. After SiO 2 dielectric was passivated by OTS8 (octyl(trichlorosilane)), all three polymers were spun onto substrates by 2000 rpm/1 min. 60 nm thick film was created. Coated substrates were sequentially heated under 80° C. for 10 min. Thermal evaporator was applied to deposit 100 nm metal contacts on polymer layer through a silicon shadow mask. Defined channel was 20 μm long and 1 mm wide. Devices were tested on a Signatone probe station inside a nitrogen glovebox with atmosphere <1 ppm oxygen concentration. Data were all collected by a Keithley 4200 system. Mobility was extracted from saturation regime based on the following equation,
[0000]
I
D
=
1
2
μ
C
W
L
(
V
G
-
V
T
)
2
[0000] where, W is the channel width (1 mm), L is the channel length (20 μm), μ is the carrier mobility, V G is the gate voltage, and V T is the threshold voltage. The capacitance, C, of the SiO 2 is 14 nF/cm 2 .
Example 3C
[0109] Polymer Solar Cells
Device Architecture: ITO/Thermal Evaporated MoO x /Polymer:PCBM/Al (Conventional)
[0110] Fabrication of PSCs: Polymer solar cells with conventional device architecture of ITO/MoO x /polymer:PCBM/Al were fabricated according to the following procedure. The ITO-coated glass substrates were firstly cleaned by ultrasonic treatment in detergent, deionized water, acetone and isopropyl alcohol for 30 minutes each, and subsequently dried in an oven overnight. MoO x film was deposited onto ITO substrates by thermal evaporation in a vacuum of about 1×10 −6 Torr. The evaporation rate was 0.1 Å/s. Two solutions containing a mixture of PIPT-RA:PC 71 BM (1:4) and PIPT-RG:PC 71 BM (1:4) in o-DCB with a concentration of 10 mg/ml were spin-casted on top of MoO x film, respectively. The thickness of blend films were controlled by the spin-casting speed and optimized at 80 nm. After that, the BHJ films were annealing at 100° C. for 10 min. Finally, the cathode (Al, ˜100 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Torr. The active area of device was 0.106 cm 2 .
[0111] PSCs Characterization: The thickness of the multilayer was measured with a profilometer and Atomic Force Microscope (AFM), respectively. Current density-voltage (J-V) characteristics were measured using a Keithley 2602 Source measure Unit, under solar simulation conditions of 100 mW/cm 2 AM 1.5 G using a 300 W Xe arc lamp with an AM 1.5 global filter. The illumination intensity of the solar simulator was measured using a standard silicon photovoltaic with a protective KG 1 filter calibrated by the National renewable Energy Laboratory.
[0112] Devices data: FIG. 18 ( a ) illustrates the characteristics of the optimized BHJ solar cell using PIPT-RG as donor materials. The optimized blend ratio of PIPT and fullerene is 1:4. Detailed comparisons of different blend ratio are not shown here. Using PIPT-RG as donor materials shows a PCE of 5.5%. Moreover, the IPCE spectrum shown in FIG. 12 18 ( b ) is in good agreement with the J-V values.
Device Architecture: ITO/Solution Processed MoO x /Polymer:PCBM/Al (Conventional)
[0113] Preparation of MoO x solution: The aqueous MoO x solution was prepared by hydration method according to the procedure reported by Liu et al (Fengmin Liu, Zhiyuan Xie, et al. Solar Energy Materials & Solar Cells. 2010, 94, 94842-845, incorporated by reference herein). Ammonium molybdate ((NH 4 ) 6 Mo 7 O 24 ) was dissolved in water to form 0.01 mol/L solution, marked as solution A. 2 mol/L hydrochloric acid (HCl) water solution was marked as solution B. Solution B was dropped into solution A until the pH value of the mixed solution was adjusted between 1.5 and 2.0. This mixed solution was marked as solution C, which is the aqueous MoO x solution
[0114] Fabrication of PSCs (Pre-thermal annealing): Polymer solar cells with conventional device architecture of ITO/MoO 3 /polymer:PCBM//Al were fabricated according to the following procedure. The ITO-coated glass substrates were firstly cleaned by ultrasonic treatment in detergent, deionized water, acetone and isopropyl alcohol for 30 minutes each, and subsequently dried in an oven overnight. After treatment with UV/ozone for 20 min, MoO x (filtered at 0.45 μm) was spin-coated from aqueous solution at 5000 rpm for 40 s to form a film of ˜8 nm thickness. The substrates were then baked at 160° C. for 25 min in air, and moved into a glovebox for spin-casting the active layer. Two solutions containing a mixture of PIPT-RA:PC 71 BM and PIPT-RG:PC71BM with different blend ratios in o-DCB with a concentration of 10 mg/ml were spin-casted on top of MoO x layer, respectively. The film thickness of ˜90 nm was optimized by controlling the spin-casting speed. After that, the BHJ films were annealed at 100° C. for 10 min. Finally, the cathode (Al, ˜100 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Torr. The active area of the devices was 0.106 cm 2 .
[0115] Fabrication of PSCs (Post-thermal annealing): Polymer solar cells with conventional device architecture of ITO/MoO 3 /polymer:PCBM//Al were fabricated according to the following procedure. The ITO-coated glass substrates were firstly cleaned by ultrasonic treatment in detergent, deionized water, acetone and isopropyl alcohol for 30 minutes each, and subsequently dried in an oven overnight. After treated with UV/ozone for 20 min, MoO x (filtered at 0.45 μm) was spin-coated from aqueous solution at 5000 rpm for 40 to form a film of ˜8 nm thickness. The substrates were then barked at 160° C. for 25 min in air, and moved into a glovebox for spin-casting the active layer. Two solutions containing a mixture of PIPT-RA:PC 7I BM and PIPT-RG:PC 71 BM with different blend ratio in o-DCB with a concentration of 10 mg/ml were spin-casted on top of MoO x layer, respectively. The film thickness of ˜90 nm was optimized by controlling the spin-casting speed. After that, the cathode (Al, 100 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Torr. Finally, the devices were annealing at 100° C. for 10 min. The active area of device was 0.106 cm 2 .
[0116] Fabrication of PSCs (Additive): Polymer solar cells with conventional device architecture of ITO/MoO 3 /polymer:PCBM/Al were fabricated according to the following procedure. The ITO-coated glass substrates were firstly cleaned by ultrasonic treatment in detergent, deionized water, acetone and isopropyl alcohol for 30 minutes each, and subsequently dried in an oven overnight. After treated with UV/ozone for 20 min, MoO x (filtered at 0.45 μm) was spin-coated from aqueous solution at 5000 rpm for 40 s to form a film of ˜8 nm thickness. The substrates were then barked at 160° C. for 25 min in air, and moved into a glovebox for spin-casting the active layer. The solutions containing a mixture of PIPT-RG:PC 71 BM (1:4) with different amount of additive in o-DCB with a concentration of 10 mg/ml were spin-casted on top of MoO x layer, respectively. The film thickness of ˜90 nm was optimized by controlling the spin-casting speed. After that, the BHJ films were annealing at 100° C. for 10 min. Finally, the cathode (Al, ˜100 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Torr. The active area of device was 0.106 cm 2 .
[0117] Fabrication of PSCs (CPE): Polymer solar cells with conventional device architecture of ITO/MoO 3 /polymer:PCBM/Al were fabricated according to the following procedure. The ITO-coated glass substrates were firstly cleaned by ultrasonic treatment in detergent, deionized water, acetone and isopropyl alcohol for 30 minutes each, and subsequently dried in an oven overnight. After treated with UV/ozone for 20 min, MoO x (filtered at 0.45 μm) was spin-coated from aqueous solution at 5000 rpm for 40 s to form a film of ˜8 nm thickness. The substrates were then barked at 160° C. for 25 min in air, and moved into a glovebox for spin-casting the active layer. Two solutions containing a mixture of PIPT-RA:PC 71 BM and PIPT-RG:PC 71 BM with different blend ratio in o-DCB with a concentration of 10 mg/ml were spin-casted on top of MoO s layer, respectively. The film thickness of ˜90 nm was optimized by controlling the spin-casting speed. After that, the BHJ films were annealing at 100° C. for 10 min. Then, CPE was spin-casting on the active layer to form a very thin interfacial layer. Finally, the cathode (Al, ˜100 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Torr. The active area of device was 0.106 cm 2 .
[0118] PSCs Characterization: The thickness of the multilayer was measured with a profilometer and Atomic Force Microscope (AFM), respectively. Current density-voltage (J-V) characteristics were measured using a Keithley 2602 Source measure Unit, under solar simulation conditions of 100 mW/cm 2 AM 1.5 G using a 300 W Xe arc lamp with an AM 1.5 global filter. The illumination intensity of the solar simulator was measured using a standard silicon photovoltaic with a protective KG1 filter calibrated by the National renewable Energy Laboratory.
[0119] Device data: FIG. 19( a ) illustrates the J-V characteristics of the optimized BHJ solar cell based on PIPT-RA and PIPT-RG as donor materials, respectively. Detailed comparisons of different blend ratio are summarized in Table 11. It could be seen that the performance of PIPT-RG devices is much better than that of PIPT-RA devices, corresponding to PCE increases of from 3.4% to 5.1%. From FIG. 19( b ) we could see that the IPCE spectrum of PIPT-RG based devices is more broadened than that of PIPT-RA based devices, which is in good agreement with the increased J SC .
[0000]
TABLE 11
Summary of solar cell device performance with different blend ratios
Ratio
Voc
Jsc
FF
PCE
Thickness
Rs
Rsh
Device
(x:y)
(V)
(mA/cm 2 )
(%)
(%)
(nm)
(KΩ)
(KΩ)
PIPT-
1:1
0.82
5.11
30
1.3
63
RR:PC 71 BM
1:2
0.84
8.89
39
2.9
80
1:3
0.88
10.68
45
4.2
85
1:4
0.88
12.11
48
5.1
91
0.07
639
PIPT-Ra:PC 71 BM
1:3
0.74
8.35
37
2.3
90
1:4
0.82
10.08
40
3.4
87
0.13
545
[0120] To achieve a better FF, more fabrication methods are used, such as post-thermal annealing (annealing devices after evaporation cathode), adding a different amount of additive (DIO), and spin-casting CPE as interfacial layer between the active layer and cathode, et al. From a starting rough experiment value showed in FIG. 20 , we find that post-thermal annealing is not as good as the pre-thermal annealing (annealing active layer before Al evaporation), whereas adding a proper amount of DIO to the fresh solution is a good way to get a better morphology of blend film.
Device Architecture: ITO/ZnO/PIPT-RG:PCBM/MoO//Ag (Inverted)
[0121] Preparation of ZnO precursor: Preparation of the ZnO Precursor: The ZnO precursor was prepared by dissolving zinc acetate dihydrate (Zn(CH 3 COO) 2 .2H 2 O, Aldrich, 99.9%, 1 g) and ethanolamine (NH 2 CH 2 CH 2 OH, Aldrich, 99.5%, 0.28 g in 2-methoxyethanol (CH 3 OCH 2 CH 2 OH, Aldrich, 99.8%, 10 mL) under vigorous stirring for 12 h for the hydrolysis reaction in air.
[0122] Fabrication of Inverted PSCs: Inverted solar cells were fabricated on ITO-coated glass substrates. The ITO-coated glass substrates were first cleaned with detergent, ultrasonicated in water, actone and isopropyl alcohol, and subsequently dried overnight in an oven. The ZnO precursor solution was spin-cast on top of the ITO-glass substrate. The films were annealed at 150° C. for 1 h in air. The ZnO film thickness was approximately 30 nm, as determined by a profilometer. The ZnO-coated substrates were transferred into a glove box.
[0123] A solution containing a mixture of PIPT-RG:PC 71 BM (1:4) in o-DCB with a concentration of 10 mg/ml was spin-casted on top of a ZnO film with thickness of approximately 80 nm, respectively. The BHJ film was heated at 100° C. for 10 min. Then, a thin layer of MoO x film (≈6 nm) was evaporated on top of the BHJ layer. Finally, the anode (Ag, ≈60 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Torr. The active area of device was 0.05 cm 2 .
[0124] PSCs Characterization: The thickness of multilayers was measured with a profilometer and Atomic Force Microscope (AFM), respectively. Current density-voltage (J-V) characteristics were measured using a Keithley 2602 Source measure Unit, under solar simulation conditions of 100 mW/cm 2 AM 1.5 G using a 300 W Xe arc lamp with an AM 1.5 global filter. The illumination intensity of the solar simulator was measured using a standard silicon photovoltaic with a protective KG1 filter calibrated by the National renewable Energy Laboratory.
[0125] Device data: FIG. 21( a ) illustrates the J-V characteristics of the optimized BHJ solar cell based on PIPT-RG as donor material. The device shows a nice open circle voltage of 0.88 V and short circle current Of 14.1 mA/cm 2 . Although the FF is relatively low, the PCE is up to 6.2%, which is very comparable to our conventional devices. This consistent value indicated that even when using different device structures, region-regular PIDTPT polymer can distinctly improved OPV devices.
Example 4
[0126] The inventors recognize that achieving structurally more precise narrow band materials is relevant within the context of bulk heterojunction polymer solar cells, where improved charge carrier transport could potentially impart higher short circuit currency (I SC ) and power conversion efficiencies (PCE). Copolymers based on cyclopenta[2,1-b:3,4-b′]dithiophene (CDT) as donor showed a relatively low open circuit voltage (V oc ) of about 0.4 V. The inventors realize that replacement of the carbon bridge in CDT unit by a silicon bridge, with the new donor of silolo[3,2-b:4,5-b′]dithiophene (SDT), might decrease the highest occupied molecular orbital (HOMO) energy level, and that OPVs incorporating SDT-PT-based conjugated copolymers might show higher Voc values than that of CDT-PT copolymers. Thus, using of SDT-PT-based regioregular copolymers as the active layer can achieve improved J SC and PCE in OPVs.
Experimental
Synthesis of PSDTPT2-EH
[0127] Monomers 4,4-bis(2-ethylhexyl)-2,6-bis(trimethylstannyl)-4H-silolo[3,2-b:4,5-b′]dithiophene (74.4 mg, 0.1 mmol) and 4,4′-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b′]dithiophene-2,6-diyl)bis(7-bromo-[1,2,5]thiadiazolo[3,4-c]pyridine) (84.6 mg, 0.1 mmol) were added to a 2-5 mL microwave tube, then Pd(PPh 3 ) 4 (5.8 mg, 0.005 mmol) and freshly distilled xylenes (3 ml) were added into the microwave tube. The tube was sealed and subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 40 min. The reaction was allowed to cool to room temperature, then tributyl(thiophen-2-yl)stannane (20 μl) was added and the reaction was subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 20 min. After the reaction was cooled to room temperature, 2-bromothiophene (20 μl) was added and the end-capping procedure was repeated once again. The mixture was precipitated in methanol, collected via centrifugation. The collected solid fibers were loaded into a cellulose extraction thimble and washed successively with methanol (6 hours), acetone (6 hours), hexanes (12 hours), and the polymer comes out with chloroform (within 2 hours) from the thimble. Chloroform was removed under reduced pressure and resulted solid was dried over high vacuum line to final products with yield of 85%. GPC with 1,2,4-trichlorobenzene as eluent at 150° C. showed number average molecular weight (Mn) of 22 KDa with polydispersity (PDI) of 1.9.
Synthesis of PSDTPTR-EH
[0128] Monomers 4,4-bis(2-ethylhexyl)-2,6-bis(trimethylstannyl)-4H-silolo[3,2-b:4,5-b]dithiophene (74.4 mg, 0.1 mmol) and 4,7-dibromo-pyridal[2,1,3]thiadiazole (29.5 mg, 0.1 mmol) were added to a 2-5 mL microwave tube, then Pd(PPh 3 ) 4 (5.8 mg, 0.005 mmol) and freshly distilled xylenes (3 ml) were added into the microwave tube. The tube was sealed and subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 40 min. The reaction was allowed to cool to room temperature, then tributyl(thiophen-2-yl)stannane (20 μl) was added and the reaction was subjected to the following reaction conditions in a microwave reactor: 80° C. for 2 min, 130° C. for 2 min, 170° C. for 2 min and 200° C. for 20 min. After the reaction was cooled to room temperature, 2-bromothiophene (20 μl) was added and the end-capping procedure was repeated once again. The mixture was precipitated in methanol, collected via centrifugation. The collected solid fibers were loaded into a cellulose extraction thimble and washed successively with methanol (6 hours), acetone (6 hours), hexanes (12 hours), and the polymer comes out with chloroform (within 2 hours) from the thimble. Chloroform was removed under reduced pressure and resulted solid was dried over high vacuum line to final products with yield of 80%. GPC with 1,2,4-trichlorobenzene as eluent at 150° C. showed number average molecular weight (Mn) of 27 KDa with polydispersity (PDI) of 2.1.
[0129] PC 7I BM (99.5%) was purchased from Nano-C. Chlorobenzene (CB, anhydrous, 99%) was supplied by Sigma-Aldrich Company. All materials were used as received.
[0130] The structures of the regiorandom polymer PSDTPTR-EH and the regioregular polymer PSDTPT2-EH used in this study are shown in Scheme 6.
[0000]
Device Architecture: ITO/PEDOT:PSS/PSDTPT:PCBM/Al (Conventional)
[0131] Fabrication of PSCs: Polymer solar cells with conventional device architecture of ITO/PEDOT:PSS/PSDTPT:PCBM/Al were fabricated according to the following procedure. The ITO-coated glass substrates were firstly cleaned by ultrasonic treatment in detergent, deionized water, acetone and isopropyl alcohol for 30 minutes each, and subsequently dried in an oven overnight. After treated with UV/ozone for 20 min, PEDOT:PSS (Baytron P VP Al 4083, filtered at 0.45 μm) was spin-coated from aqueous solution at 4000 rpm for 40 s to form a film of ˜40 nm thickness. The substrates were barked at 140° C. for 10 min in air, and then moved into a glovebox for spin-casting the active layer. Two solution containing with PSDTPT2-EH:PC 71 BM (1:1, w/w) and PSDTPTR-EH:PC 71 BM (1:1, w/w) in CB with a concentration of 10 mg/ml were then spin-casted on top of PEDOT:PSS layer, which were marked as device I and device II, respectively. The film thickness of ˜80 nm was controlled by adjusting the spin-casting speed. In order to evaporate the solvent quickly, the BHJ films were dried at 70° C. for 10 min. After that, the cathode (Al, ˜100 nm) was deposited through a shadow mask by thermal evaporation in a vacuum of about 3×10 −6 Ton. The active area of device was 0.106 cm 2 .
[0132] PSCs Characterization: The thickness of the active layer and PEDOT:PSS was measured with a profilometer. Current density-voltage (TV) characteristics were measured using a Keithley 2602 Source measure Unit, under solar simulation conditions of 100 mW/cm 2 AM 1.5 G using a 300 W Xe arc lamp with an AM 1.5 global filter. The illumination intensity of the solar simulator was measured using a standard silicon photovoltaic with a protective KG1 filter calibrated by the National renewable Energy Laboratory.
[0133] Devices data: FIG. 22 illustrates the characteristics of the two devices, and the detailed comparisons are summarized in Table 12. Using the regioregular copolymers, the short circuit current density (10 of device II increases as much as four times (from 2.41 to 9.03 mA/cm 2 ) compared with that of device I using the regionrandom copolymers. As is known, the J SC is not only determined by the number of absorbed photons, but also heavily influenced by the component morphology in the active layer. Therefore, a remarkable increase in J SC for the device II implies that the morphology of the active layer has been substantially improved. Moreover, the open circuit voltage (V OC ) and Fill Factor (FF) increased slightly, and the power conversion efficiency (PCE) of device II is up to 1.96%.
[0000]
TABLE 12
Summary of solar cell device performance based on
PSDTPTR-EH and PSDTPT2-EH copolymers
V oc
J sc
FF
PCE
Devices
(V)
(mA/cm 2 )
(%)
(%)
PSDTPTR-
0.56
2.41
35.9
0.48
EH
PSDTPT2-EH
0.58
9.03
37.3
1.96
Example 5
[0134] High mobility lies in the heart of practical applications for organic electronics. High mobility enables low operating voltage and less energy consumption in organic thin film transistors (OTFTs). Recently, narrow bandgap donor-acceptor (DA) copolymers are attracting researchers' attention. The combination of DA moieties on polymer chain can induce preferred charge transfer between DA units with different electron affinities. Therefore, delocalization, improved transport and higher mobility are expected.
[0135] An outstanding class of polymers composed of cyclopenta[2,1-b:3,4-b′]dithiophene (CDT) and 2,1,3-benzothiadiazole (BT) has been reported [14-18]. After replacing BT unit by pyridal[2,1,3]thiadiazole (PT) with larger electron affinity difference to CDT, higher mobility was demonstrated on regioregular-PCDTPTI (rr-P1) (see FIG. 23 ) and regioregular-PCDTPT2 (rr-P2) but not in regiorandom-PCDTPTR (ra-P3). Ra-P3 only gave μ=5×10 −3 cm 2 /Vs while μ=0.6 and 0.4 cm 2 /Vs, respectively, were obtained by rr-P2 and rr-P1 [19]. Molecular structures of the three polymers, device architecture, and work functions are shown in FIG. 23 . In order to further increase the mobility, larger molecular weight and films with improved structural order are required. However, to precisely characterize the performance from the different mass distribution of the synthesized polymers, low polydispersity index (PDI) is important as well as molecular weight.
[0136] Using gel permeation chromatography (GPC), it is possible to fraction different partitions of molecular weight with low PDI from rr-P2. By controlling collecting time of permeated polymer solution, high molecular weight 300 kDa with PDI≈1.6 was collected and high mobility, μ=2.5 cm 2 /Vs, was demonstrated after annealing. Improved alky stacking with annealing temperature was confirmed by a growing peak in X-ray diffraction (XRD) spectra. Obvious fiber structure was observed after the film was annealed over 300° C. Thus, the high mobility, over 2 cm 2 /Vs, after annealing could be correlated to the higher degree of structural order in films of high molecular weight rr-P2. To push mobility even higher than 2.5 cm 2 /Vs, inducing higher molecular weight and more ordering in polymer film are promising. However, to further increase the molecular weight by GPC is impractical because of the required collecting time and the quantity of the fractionated solution.
[0137] The transfer and output characteristics of the OTFTs made of rr-P2 are shown in FIGS. 24( a ) and 24 ( b ). The polymer film was drop cast on a prepatterned substrate with bottom contact (BC) architecture made of gold. The SiO 2 gate dielectric was passivated by decyl(trichloro)silane (DTS). FIG. 24( a ) shows clear transistor behavior with linear and saturation regimes and on-off ration 6×10 6 . The positive shift of threshold voltage from negative V G to V G =20 V elucidates the existence of hole traps on the interface of gold and polymer.
[0138] Table 13 is a mobility table showing drop casted films prepared from different concentration solutions after different annealing temperatures. The highest mobility value 2.5 cm 2 /Vs, was achieved from the film prepared by 0.025 wt % solution and annealed at 350° C. Even though the mobility values continuously increase with annealing temperature, the numbers saturate after 200° C., mainly varying from 1.8 to 2.3 cm 2 /Vs.
[0000]
TABLE 13
Polymer films were drop casted from various solution
concentrations. Hole mobility values after annealed at
different temperatures were collected.
Sol.
Concen-
Annealing Temp
tration
RT
100° C.
150° C.
200° C.
250° C.
300° C.
350° C.
0.1%
0.9
1.1
1.6
1.8
1.9
2.2
2.2
0.075%
1.4
1.2
1.8
2.1
2.2
2.3
2.3
0.05%
0.8
1.2
1.2
1.9
2.1
1.9
2.3
0.025%
0.8
1.4
1.6
1.8
2.0
2.1
2.5
[0139] Height and phase images shown in FIGS. 25( a ) and 25 ( b ) were obtained by atomic force microscopy, showing fiber structure with length 100 to 200 nm after annealing at 350° C. XRD spectra with temperature dependence shown in FIGS. 26( a ) and 26 ( b ) confirms the ordered structure increasing with annealing temperature. The peak at 2θ=3.3° can be correlated to 2.7 nm alkyl packing. As demonstrated in Table 13, because mobility values obviously increase with annealing temperature, the increasing mobility can be associated with the increasing ordered alkyl packing.
[0140] The dark spots in the image are actually holes in the film.
[0141] To further optimize device performance, contact resistance (R c ) was also studied. R c shown in FIG. 27 demonstrates a largest R c =21.5 kΩ at RT, decreases to 5.4 kΩ after 250° C. annealing, and increases to 14.7 kΩ after annealed at 350° C. R c was significantly reduced by factor 4 after annealed at 250° C. The increase of R c after 350° C. annealing could come from possible thermal decomposition of the polymer films that degrades the interface between polymer and metal contact.
[0142] Through comparing the temperature dependence among Table 13, AFM images in FIG. 25 , and XRD spectra in FIG. 26 , we concluded the high mobility over 2 cm 2 /Vs was from the ordered packing of the high molecular weight rr-P2 after annealing. In order to advance the performance of this polymer system, higher molecular weight and more ordering in polymer film are both important.
Experimental
[0143] PCDTPT2 (P2) was originally synthesized with 55 kDa and PDI>4. To collect high molecular weight P2 by gel permeated chromatography (GPC), 75 mg P2 was dissolved in chloroform (0.25% triethylamine) with 1 mg/ml concentration. Permeated solution was collected within 6 sec and produced P2 with 300 kDa and PDI=1.6. After drying, then, the high molecular weight P2 was dissolved in chlorobenzene with 0.1, 0.075, 0.05, and 0.025 wt % for drop casting on bottom contact substrates passivated by decyl(trichloro)silane. The casted substrates were kept in a glovebox with oxygen level less than 2 ppm, drying for 6 hours. All devices were tested in a nitrogen environment and data were collected by Keithley 4200.
REFERENCES
[0144] The following publications are incorporated by reference herein in their entireties:
1. (a) Bürgi, L.; Turbiez, M.; Pfeiffer, R.; Bienewald, F.; Kirner, H.-J.; Winnewisser, C. Adv. Mater. 2008, 20, 2217-2224. (b) Bijleveld, J. C.; Zoombelt, A. P.; Mathijssen, S. G. J.; Wienk, M. M.; Turbiez, M.; de Leeuw, D. M.; Janssen, R. A. J. Am. Chem. Soc. 2009, 131, 16616-16617. (c) Li, Y. N.; Sonar, P.; Singh, S. P.; Soh, M. S.; van Meurs, M.; Tan, J. J. Am. Chem. Soc. 2011, 133, 2198-2204. (d) Yan, H.; Chen, Z. H.; Zheng, Y.; Newman, C.; Quinn, J. R.; Dotz, F.; Kastler, M.; Facchetti, A. Nature, 2009, 457, 679-687. 2. (a) Son, H. J.; Wang, W.; Xu, T.; Liang, Y. Y.; Wu, Y.; Li, G.; Yu, L. P. J. Am. Chem. Soc. 2011, 133, 1885-1894. (b) Liang, Y. Y.; Xu, Z.; Xia, J. B.; Tsai, S. T.; Wu, Y.; Li, G.; Ray, C.; Yu, L. P. Adv. Mater. 2010, 22, E135-E138. 3. (a) Zhang, M.; Tsao, H. N.; Pisula, W.; Yang, C.; Mishra, A. K.; Müllen, K. J. Am. Chem. Soc. 2007, 129, 3472-3473. (b) Tsao, H. N.; Cho, D.; Andreasen, J. W.; Rouhanipour, A.; Breiby, D. W.; Pisula, W.; Müllen, K. Adv. Mater. 2009, 21, 209-212. (c) Tsao, H. N.; Cho, D. M.; Park, I.; Hansen, M. R.; Mavrinskiy, A.; Yoon, D. Y.; Graf, R.; Pisula, W.; Spiess, H. W.; Müllen, K. J. Am. Chem. Soc. 2011, dx.doi.org/10.1021/ja 108861q. 4. Welch, G. C.; Coffin, R.; Peet, J.; Bazan, G. C. J. Am. Chem. Soc. 2009, 131, 10802-10803. 5. Blouin, N.; Michaud, A.; Gendron, D.; Wakim, S.; Blair, E.; Neagu-Plesu, R.; Belletete, M.; Durocher, G.; Tao, Y.; Leclerc, M. J. Am. Chem. Soc. 2008, 130, 732-742. 6. Zhou, H. X.; Yang, L. Q.; Price. S. C.; Knight, K. J.; You, W. Angew. Chem. Mt. Ed. 2010, 49, 7992-7995. 7. (a) Yamamoto, T.; Arai, M.; Kokubo, H. Macromolecules 2003, 36, 7986-7993. (b) Nambiar, R.; Woody, K. B.; Ochocki, J. D.; Brizius, G. L.; Collard, D. M. Macromolecules 2009, 42, 43-51. 8. Osaka, I.; McCullough, R. D. Acc. Chem. Res. 2008, 41, 1202-1214. 9. (a) Tilley, J. W.; Zawoiski, S. J. Org. Chem. 1988, 53, 386-390. (b) Schroter, S.; Stock, C.; Bach, T. Tetrahedron, 2005, 61, 2245-2267. (c) Handy, S. T.; Wilson, T.; Muth, A. J. Org. Chem. 2007, 72, 8496-8500. 10. Coffin, R.; Peet, J.; Rogers, J.; Bazan, G. C. Nat. Chem. 2009, 1, 657-661. 11. Sun, Y.; Chien, S. C.; Yip, H. L.; Zhang, Y.; Chen, K. S.; Zeigler, D. F.; Chen, F. C.; Lin, B. P.; Jen, A. K. Y. J Mater Chem 2011, 21, 13247-13255. 12. Lei Ying, Guillermo C. Bazan, et al. J. Am. Chem. Soc. 2011, 133, 18538-18541. 13. Fengmin Liu, Zhiyuan Xie, et al. Solar Energy Materials & Solar Cells. 2010, 94, 94842-845. 14. Bijleveld, J. C.; Zoombelt, A. P.; Mathijssen, S. G. J.; Wienk, M. M.; Turbiez, M.; de Leeuw, D. M.; Janssen, R. A., J. Am. Chem. Soc. 2009, 131, 16616 15. Wang, M.; Hu, X. W.; Liu, P.; Li, W.; Gong, X.; Huang, F.; Cao, Y. J. Am. Chem. Soc. 2011, 133, 9638. 16. Li, Y. N.; Sonar, P.; Singh, S. P.; Soh, M. S.; van Meurs, M.; Tan, J., J. Am. Chem. Soc. 2011, 133, 2198 17. Yan, H.; Chen, Z. H.; Zheng, Y.; Newman, C.; Quinn, J. R.; Dotz, F.; Kastler, M.; Facchetti, A., Nature 2009, 457, 679 18. Zhang, W. M.; Smith, J.; Watkins, S. W.; Gysel, R.; McGehee, M.; Salleo, A.; Kirkpatrick, J.; Ashraf, S.; Anthopoulos, T.; Heeney, M.; McCulloch, I., J. Am. Chem. Soc. 2010, 132, 11437 19. Lei Ying, Ben B. Y. Hsu, Hongmei Zhan, Gregory C. Welch, Peter Zalar, Louis A. Perez, Edward J. Kramer, Thuc-Quyen Nguyen, Alan J. Heeger, Wai-Yeung Wong, and Guillermo C. Bazan, J. Am. Chem. Soc. 2011, 133, 18538
[0164] Although the present invention has been described in connection with the preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the principles and scope of the invention, as those skilled in the art will readily understand. Accordingly, such modifications may be practiced within the scope of the invention and the following claims. | A method of regioselectively preparing a pyridine-containing compound is provided. In particular embodiments, the method includes reacting halogen-functionalized pyridal[2,1,3]thiadiazole with organotin-functionalized cyclopenta[2,1-b:3,4-b′]dithiophene or organotin-functionalized indaceno[1,2-b:5,6-b′]dithiophene. Also provided is a method of preparing a polymer. The method includes regioselectively preparing a monomer that includes a pyridal[2,1,3]thiadiazole unit; and reacting the monomer to produce a polymer that includes a regioregular conjugated backbone section, wherein the section includes a repeat unit containing the pyridal[2,1,3]thiadiazole unit. A polymer that includes a regioregular conjugated backbone section, and electronic devices that include the polymer, are also provided. | 2 |
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to storm louvers having a plurality of spaced blades for removing water particles from air flowing into buildings or air handling equipment. More particularly, the invention relates to a louver having an improved support frame for supporting the blades. The invention also relates to a modular louver system having a plurality of individual louvers that can be easily connected and installed in openings of nearly any size.
2. DESCRIPTION OF THE PRIOR ART
Louvers for separating water and other particles from air flowing into buildings or air handling equipment are known in the art. Such prior art louvers typically include a plurality of curved, spaced blades that define a plurality of spaced, serpentine-shaped air passageways therebetween. The air passageways direct air from the exterior of the building or air handling equipment to the interior of the building or air handling equipment for air conditioning of the building.
When air passes into the building or air handling equipment through the air passageways, the water particles in the air, which are heavier than the gas molecules in the air, cannot turn through the serpentine-shaped contours in the air passageways. The water molecules therefore strike the walls of the blades, agglomerate into drops and flow by gravity down the blades and out of the louvers.
To achieve a consistent and desired water removal rate without excessively impeding the flow of air into the building or air handling equipment, the blades in the louvers must be spaced and supported in a uniform configuration. Known prior art louvers support their blades with rods that extend through holes formed in the tops and bottoms of the blades. The blades are spaced apart on the rods with spacers.
To assemble these types of louvers, the support rods are first inserted through the holes in the upper and lower edges of one of the blades. Spacers are then placed adjacent the blade, and another blade is placed on the rods adjacent the spacers so that the blades are spaced relative to one another. These steps are then repeated for each and every blade of the louver.
Unfortunately, these steps are time consuming because the blades and spacers must be individually and serially placed on the rods. These types of support assemblies are also somewhat flimsy because the holes formed in the blades must be large enough to allow the blades to slide over the rods. Thus, the blades tend to shift relative to one another on the rods when the louver is moved.
Another limitation of known prior art louvers is that they are assembled as single units regardless of the size of the openings they are mounted in. This is a problem when a louver must be installed in a large opening because the louver must be assembled with long support rods and a large number of blades to span the entire width of the opening, thus creating a finished louver that is extremely large and heavy.
A further limitation of known prior art louvers is that they do not include integral drainage assemblies for collecting and draining the water particles removed from the air. Prior art louvers must therefore be equipped with separate gutters or down spouts or other drainage systems for carrying the removed water away from the louver and out of the building or equipment.
OBJECTS AND SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide a louver having an improved blade support assembly.
It is a more particular object of the present invention to provide a louver with a blade support assembly that permits the blades to be more quickly and easily mounted within the support assembly and that more firmly supports the blades, resulting in an assembled louver that is strong and rigid.
It is another object of the present invention to provide a louver having an integral drainage system for collecting and draining water removed from the air away from the louver and out of the building or equipment.
It is a further object of the present invention to provide a louver system that can fit within nearly any size opening without creating individual louvers that are large, heavy and cumbersome to install.
The present invention achieves these objects and other objects that become evident from the description of the preferred embodiments of the invention herein by providing a louver with an improved blade support assembly and an integral draining system, and by providing a modular louver system that can be easily assembled to fit within openings of nearly any size.
The louver of the present invention broadly includes a plurality of elongated blades each having opposed lower and upper edges and a support frame for supporting the blades in a horizontally-spaced and vertically extending configuration so that the blades define therebetween a plurality of horizontally-spaced and vertically extending air passageways for the passage of air into a building or equipment. The preferred support frame includes a bottom frame member for receiving and supporting the lower edges of the blades and a top frame member for receiving and supporting the upper edges of the blades.
The preferred bottom frame member includes a pair of generally horizontally-extending ledges each including a plurality of horizontally-spaced slots formed therein and at least one horizontally-extending shelf spaced below one of the ledges. The blades are mounted in the support frame by inserting the lower edges of the blades through the slots in the ledges so that the blades rest on top of the shelf. This configuration permits the blades to be quickly and easily slid into the support frame and results in a louver that is substantially stronger and more rigid than prior art louvers.
The bottom frame member also includes a generally horizontally-extending base portion spaced below the ledges and shelf and having a plurality of drain holes formed therein. Water removed from the air by the blades is collected in the base portion and drained from the louver through the drain holes. The configuration creates an integral "drain pan" in each louver that collects and removes water from the louver independently of other louvers.
The present invention also includes connection structure for connecting two or more of the louvers together to form a single modular louver system. Any number of louvers may be connected to form a louver system of nearly any size for mounting within openings of nearly any size. In addition, the louvers employ an integral mullion member. This eliminates the need for separate mullion strips to be installed after the louvers are connected together to seal the joints between the two louvers.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
A preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein:
FIG. 1 is a front elevational view of a pair of louvers constructed in accordance with a preferred embodiment of the present invention showing the louvers separated to illustrate the connecting structure;
FIG. 2 is a fragmented front elevational view of the louvers with parts broken away;
FIG. 3 is a top sectional view of the louvers taken along line 3--3 of FIG. 2;
FIG. 4 is a side sectional view of the louvers taken along line 4--4 of FIG. 2; and
FIG. 5 is a plan view of one of the blades of the louvers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawing figures and particularly FIGS. 1 and 3, a pair of louvers 10,12 constructed in accordance with a preferred embodiment of the invention is illustrated. As illustrated in FIG. 4, the louvers 10,12 are configured for placement within or adjacent to an opening 14 in a building for permitting air to flow into the building while removing water particles from the air to prevent excess moisture from entering the building. Each louver 10,12 may be installed in the opening 14 individually or the louvers may be connected together or connected with additional louvers to form a multi-unit modular louver system discussed below.
Each louver 10,12 broadly includes a plurality of elongated blades 16a, 16b, 16c, 16d and a support frame generally referred to by the numeral 18 for supporting the blades in a horizontally-spaced and vertically extending configuration. The louvers 10,12 are substantially identical; therefore, their components are identified with the same numerals herein.
The blades 16a, 16b, 16c, 16d are preferably formed from extruded aluminum and, as best illustrated in FIGS. 4 and 5, each presents a generally sine wave-shaped profile with opposed lower and upper edges 20,22, opposed front and rear edges 23,25, and opposed right and left vertically extending faces 24,26. The blades 16a, 16b, 16c, 16d are preferably approximately 6' in length and 6-120' in height, but may be formed in other sizes as a matter of design choice.
The blades 16a are positioned in the intermediate locations of the louvers 10,12 and each includes an arcuate hook 28 and an angled tab 30 extending from its right face 24 and a plurality of horizontally-spaced projections 32 and an L-shaped tab 34 extending outwardly from its left face 26 (see FIG. 5). Each blade 16a also includes a pair of slightly enlarged tabs 36 at its front and rear edges 23,25.
The blades 16b are positioned in the leftmost positions of each louver 10,12 when the louvers are installed individually. However, when two or more louvers are connected together as illustrated in FIG. 3, the blades 16b are positioned at the leftmost position of the left louver only. The blades 16b are similar to the blades 16a except that they do not include projections or a tab extending from their left faces 26. This is because the blades 16b do not have air passing along their left faces. Additionally, the front and rear edges 23,25 of each blade 16b include a generally U-shaped connection channel 38 rather than an enlarged tab.
The blades 16c are positioned in the rightmost positions of each louver 10,12 and are similar to the blades 16a except that they do not include a hook or tab extending from their right faces 24. This is because the blades 16c do not have air passing along their right faces. Additionally, the front and rear edges 23,25 of each blade 16c include a generally U-shaped connection channel 38 rather than an enlarged tab.
The blades 16d are only used when two or more louvers 10,12 are connected together as illustrated in FIG. 3. The blades 16d are positioned in the leftmost positions of all the connected louvers, except the leftmost louver. The blades 16d are similar to the blades 16b except that their front and rear edges 23,25 have enlarged tabs 36 rather than U-shaped connection channels, and they each further include a pair of walls 40 extending from their left faces.
The support frame 18 of each louver 10,12 supports its blades 16a, 16b, 16c, 16d in a horizontally-spaced and vertically extending configuration so that the blades define therebetween a plurality of horizontally-spaced and vertically extending air passageways 42 extending between the exterior and the interior of the building for directing air into the building. When air passes through the air passageways 42 and past the blades 16a, 16b, 16c, 16d, the hooks 28, tabs 30,34 projections 32, as well as the curved profile of the blades cooperate for removing water particles from the air. The removed water particles are then drained from the louver as described in more detail below.
When the louvers 10,12 are installed in the opening 14 individually, each support frame 18 includes a bottom frame member 44, a top frame member 46, and a pair of end frame members 48. However, when the louvers 10,12 are connected together or with additional louvers as illustrated in FIG. 3, the end frame member 48 on the right side of the louver 10 is replaced with a female-type end frame member 50, and the end frame member 48 on the left side of the louver 12 is replaced with a male-type end frame member 52.
The components of each support frame 18 are preferably formed of extruded aluminum, but may also be formed of other suitable materials. When assembled, each support frame 18 is preferably 48' wide, 48' high, and 6' deep.
The bottom frame member 44 of each louver 10,12 is preferably configured to rest on a support 54 mounted adjacent the lower edge of the inside face of the opening 14. As best illustrated in FIG. 4, the bottom frame member 44 includes a generally horizontally-extending base portion 56, a pair of generally vertically-extending front and rear walls 58,60 extending upwardly from the front and rear edges of the base portion 56, a pair of generally horizontally-extending ledges 62,64 extending inwardly from the top edges of the walls 58,60, at least one horizontally-extending shelf 66 spaced below the ledge 64, and a pair of generally L-shaped feet 68 depending from the lower face of the base portion 56.
As best illustrated in FIG. 3, the base portion 56 includes a plurality of spaced drain holes 70 formed therein adjacent its front edge. Water particles that are removed by the blades 16 accumulate on the top face of the base portion 56 and drain out of the louver 10,12 through the drain holes 70. The drain holes 70 are preferably approximately 5/8' in diameter and are spaced 1/2' from the front edge of the base portion 56.
As illustrated in FIG. 4, a strip of flashing 72 may be placed along the lower surface of the opening 14 and under the drain holes 70 to direct the drained water out of the louver 10,12 and away from the building. Another strip of flashing 73 may be placed along the upper surface of the opening to collect and direct rain and mist away from the louvers 10,12.
Returning to FIG. 3, the ledges 62,64 of the bottom frame member 44 each include a plurality of horizontally-spaced slots 74 formed therein for receiving and supporting the blades 16a. More particularly, the blades 16a are assembled in their support frame 18 by first aligning the front and rear edges 23,25 of each blade 16a between their respective slots 74 on the ledges 62,64. The enlarged tabs 36 on the blades 16a are then inserted through the slots 74 so that the rear edges 25 of the blades rest on top of the shelf 66. This configuration permits the blades 16a to be quickly and easily slid into the support frame and results in a louver that is substantially stronger and more rigid than prior art louvers. The slots 74 are preferably spaced 1' apart so that the air passageways 42 between the blades are approximately 1' in width.
As best illustrated in FIG. 4, the top frame member 46 is configured to fit beneath a support 55 mounted adjacent the upper edge of the inside face of the opening 14. The top frame member 46 preferably includes a generally horizontally-extending cover portion 76, a plurality of transversely extending reinforcement ribs 95 extending upwardly from the top face of the cover portion 76, a pair of vertically extending front and rear walls 78,80 extending downwardly from the front and rear edges of the cover portion, and a pair of generally horizontally-extending ledges 82,84 extending inwardly from the lower edges of the front and rear walls 78,80. The top edge of the front wall 78 extends slightly above the cover portion 76 to define an integral J-shaped channel 115 adjacent the forwardmost reinforcement rib 95. Caulking may be placed in the channel 115 for sealing the louver 10,12 in the opening 14.
The ledges 82,84 each include a plurality of horizontally-spaced slots formed therein that are in vertical alignment with the slots 74 in the ledges 62,64 of the bottom frame member 44. The slots receive and support the upper edges 22 of the blades 16a when the blades are inserted in their respective support frame 18.
The end frame members 48 are attached to the left and right sides of the top and bottom frame members 44,46, and are configured to slide between supports 86 mounted along the inside face of the left and right sides of the opening 14. When the louvers 10,12 are individually placed in the opening 14, each includes a pair of end frame members 48. However, when the louvers 10,12 are connected together or connected with additional louvers, only the outermost left and right sides of the combined louver system include end frame members 48 as illustrated in FIGS. 1 and 3.
Each end frame member 48 includes a vertically extending sidewall 88, a pair of transversely extending front and rear walls 90,92 extending inwardly from the sidewall, and a plurality of transversely extending reinforcement ribs 94 extending outwardly from the sidewall. The distal ends of the front and rear walls 90,92 each include an inwardly extending tab 96 for receiving and supporting the U-shaped connection channels 38 of the blades 16b, 16c as discussed below. The proximal ends of the front walls 90 each extend slightly beyond their sidewalls 88 to define an integral J-shaped channel 116 for accepting caulking.
The male-type end frame members 52 and female-type end frame members 50 are used when it is desired to connect two or more of the louvers 10,12 together. As best illustrated in FIG. 3, each male-type end frame member 52 includes a vertically extending sidewall 98, a pair of generally L-shaped tabs 100 extending from one face of the sidewall that each define a connection channel, and a transversely extending tab 102 projecting from the opposite face of the sidewall. In addition, an integral mullion member 102A is used to seal the joints between louvers 10,12.
Each female-type end frame member 50 includes a vertically extending sidewall 104 having an inwardly projecting female-type receptacle 106 therein, a pair of transversely extending front and rear end walls 108,110 and a pair of short connection tabs 112 extending inwardly from the distal ends of the front and rear end walls 108,110.
To connect two louvers 10,12 together, a male-type end frame member 52 is first connected to a blade 16d by sliding its L-shaped tabs 100 over the inwardly projecting walls 40 of the blade 16d. The male-type end frame member 52 and blade 16d are then welded, caulked or otherwise attached to the left side of the rightmost louver 12.
A female-type end frame member 50 is then connected to a blade 16c by sliding the U-shaped connection channels 38 on the front and rear edges of the blade 16c over the connection tabs 112 on the female-type end frame member. The female-type end frame member 50 and blade 16c are then welded, caulked, or otherwise attached to the right side of the leftmost louver 10.
The louvers 10,12 are then placed adjacent one another so that the tab 102 of the male-type end frame member 52 is received within the receptacle 106 of the female-type end frame member 50 so that the sidewalls 98,104 of the male-type and female-type end frame members are flush with one another. The male and female-type end frame members 50,52 are then attached by caulking or other attachment means. Those skilled in the art will appreciate that any number of louvers may be connected together in this fashion to form a modular louver system to fit within openings of nearly any size.
Although the invention has been described with reference to the preferred embodiment illustrated in the attached drawing figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. | A storm louver (10, 12) having a plurality of spaced blades (16a, 16b, 16c, 16d) for removing water particles from air flowing into a building or air handling equipment is disclosed. Each louver (10, 12) has an improved blade support frame (18) that permits the blades (16a, 16b, 16c, 16d) to be more quickly and easily installed in the support frame (18) and that more firmly supports the blades. A modular louver system including at least two individual louvers that can be easily connected for installation in openings of any size is also disclosed. | 5 |
FIELD OF THE INVENTION
[0001] The present invention is directed to a frost-free surface and a method for making the same. More particularly, the present invention is directed to a frost-free surface for devices where the surface prevents ice build-up and resists vapor condensation when subjected to freezing conditions. The surface comprises nanoclusters of aluminum oxide that have been fabricated via a process that comprises at least one electrochemical oxidation step, and an etching or coating step.
BACKGROUND OF THE INVENTION
[0002] Ice formation/adhesion on internal surfaces of devices such as freezers can create problems, especially on freezers that are used for point-of-purchase sales. Ice build-up (resulting from warmer air with moisture entering a freezer) can interfere with the efficiency of a freezer and leave less room for food storage within compartments of the freezer.
[0003] With commercial freezers used for point-of-purchase applications, ice build-up is very unattractive for a consumer to see and often interferes with the look and presentation of product being sold. In fact, ice build-up within freezers can cover or hide product, like ice cream, meats and/or frozen vegetables, resulting in product not being selected by a consumer and often spoiling prior to being sold.
[0004] Certain freezers need to be put out of service in order to defrost. Other frost-free freezers have heating elements to melt ice which is collected as water, or blow air through the food compartment of the freezer to remove moisture laden air which is known to cause ice build-up.
[0005] Still other devices have problems with ice build-up under freezing conditions. Airplanes, automobiles, locking mechanisms as well as electronic switches are additional examples of the types of devices that can fail to function under freezing conditions.
[0006] The concern with many defrosting mechanisms is the over use of energy and affordability. Moreover, lowering temperatures of food compartments within devices like freezers typically causes food product quality to inevitably be compromised.
[0007] There is an increasing interest to create surfaces that do not display ice build-up and attract condensation under freezing conditions. There is an especially preferred interest in developing freezers that do not display ice build-up within their food storing compartments, especially through mechanisms that do not require additional energy to heat such compartments. Furthermore, there exists a desire to convert devices with poor or no de-icing capabilities into devices that are frost-free without relying on complicated heating or other electrical systems. This invention, therefore, is directed to a surface that displays reduced ice build-up and resists vapor condensation and a method for making the same. The surface typically is prepared from parts or panels that may be treated post or during device manufacturing whereby the parts or panels comprise nanoclusters of aluminum oxide that have been fabricated via a process that comprises at least one electrochemical oxidation step, and an etching or coating step.
Additional Information
[0008] Efforts have been disclosed for making frost-free freezers. In U.S. Pat. No. 4,513,579, a freezer with a moisture-absorbing regenerable filter is described.
[0009] Other efforts have been disclosed for decreasing ice adhesion. In U.S. Pat. No. 7,087,876, a system for melting interfacial ice with electrodes and an AC power source is described.
[0010] Still other efforts have been disclosed for making freezers with defrost functions. In U.S. Pat. No. 7,320,226, a freezer with a heating device for heating and defrosting a cooling surface is described.
[0011] None of the additional information above describes a surface having frost-free properties prepared post or during device manufacturing whereby the surface comprises nanoclusters of aluminum oxide that have been fabricated through a process that includes an electrochemical oxidation step, and an etching or coating step.
SUMMARY OF THE INVENTION
[0012] In a first aspect, the present invention is directed to a frost-free surface whereby the surface is superhydrophobic and comprises nanoclusters of aluminum oxide.
[0013] In a second aspect, the present invention is directed to a method for making a frost-free surface, the method comprising the steps of:
obtaining an aluminum comprising part, the aluminum comprising part suitable for assembly onto a new device or obtained from an existing device; subjecting the aluminum comprising part to at least one electrochemical oxidation step for an effective amount of time to create a part comprising a fabricated anodic aluminum oxide layer thereon; subjecting the part comprising the fabricated anodic aluminum oxide layer thereon to an etching step or a coating step to produce a superhydrophobic part comprising aluminum oxide; assembling the superhydrophobic part onto the new or the existing device.
[0018] All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow.
[0019] Aluminum oxide is meant to mean Al 2 O 3 . Anodic aluminum oxide is the aluminum oxide layer fabricated onto an aluminum part in an electrochemical oxidation step when the part comprising aluminum is used as the anode. Superhydrophobic, as used herein, means having a contact angle of at least 145° against water. Frost-free, as used herein, means a superhydrophobic surface that displays a reduction in ice build-up, reduction in the adhesion force between ice and a surface as well as a reduction in attraction of vapor condensation on a surface. Nanocluster means a collection of aluminum oxide, preferably pyramid-like in shape, where the nanocluster is from 800 nm to 15 microns in width and 700 nm to 10 microns in height. Contact angle, as used herein, means the angle at which a water/vapor interface meets a solid surface. Such an angle may be measured with a goniometer or other water droplet shape analysis system. Existing device is a device having already been manufactured. New device is a device being assembled within the manufacturing process. Part is meant to include panel like a freezer panel but is generally meant to mean any object that may be treated according to the method of this invention. Device is meant to mean an item that includes a part treated via the method of this invention like an airplane, automobile, lock, and especially, a freezer for food products. Assembly onto is meant to include within a device. For the avoidance of doubt, therefore, assembly onto includes, for example, the assembly of panels within a freezer.
[0020] All ranges defined herein are meant to include all ranges subsumed therein unless specifically stated otherwise. Comprising, as used herein, is meant to include consisting essentially of and consisting of.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The only limitations with respect to the part that may be used in this invention is that the same may be used as an anode in an electrochemical oxidation process. Such a part may be pure aluminum or an aluminum alloy and comprise elements such as copper, silicon, iron, magnesium, manganese, zinc, titanium, mixtures thereof or the , like. In a preferred embodiment, the part comprises at least 90%, and preferably, at least 95 to 100%, and most preferably, at least 99 to 100% by weight aluminum, including all ranges subsumed therein.
[0022] Moreover, the devices which may employ the parts of this invention can comprise, for example, cooling mechanisms that use propane, carbon dioxide, hydrofluorocarbons, chlorofluorocarbons, mixtures there or the like. The preferred cooling mechanism is often country dependent and the most preferred mechanism will almost always be the one deemed most environmentally friendly.
[0023] When practicing the present invention, the part is obtained and preferably thoroughly washed and dried. The washing method will be dependent on the type of soil being removed from the part. Typically, however, solvents like water, soapy water, acetone, and solutions of sodium hydroxide and/or sodium bicarbonate may be used to clean the part. Of course, non-solvent based cleaning techniques may also be used if desired. Therefore, for example, vibrating, blowing and/or ultrasonification techniques may be used to clean or further clean the part targeted for treatment. The size of the part treated according to this invention is not critical as long as suitable equipment may be obtained to conduct the inventive method. Typically, however, the parts treated according to this invention have an area of less than 100 m 2 , and preferably, less than 50 m 2 , and most preferably, from about 0.1 to about 20 m 2 , including all ranges subsumed therein. Often, such parts have a thickness that does not exceed 2 cm, and preferably, does not exceed 1.25 cm. In a most preferred embodiment, the thickness of the part is from about 0.01 cm to about 0.75 cm, including all ranges subsumed therein. Moreover, the shape of the part is not limited and the surface may, for example, be smooth, comprise grooves or be embossed. When the device having parts being treated according to this invention is a freezer, such freezers can be made commercially available from suppliers like Bush Refrigeration, Dragon Enterprise Co., Ltd., CrownTonka Walkins, Ningbo Jingco Electronics Co., Ltd. and Qingdao Haier Refrigerator Co., Ltd.
[0024] Subsequent to obtaining a cleaned part, the part is preferably subjected to a first electrochemical oxidation process whereby the part is submerged in a reagent solution comprising acid like, for example, phosphoric, sulfuric, hydrochloric, acetic, citric, tartaric or lactic acid, as well as mixtures thereof or the like.
[0025] The reagent solution typically comprises from 2 to 12% by weight, and preferably, from 3 to 10%, and most preferably, from 5 to 7% by weight acid, including all ranges subsumed therein. In an often preferred embodiment, the reagent solution comprises from 3 to about 20%, and most preferably, from about 6 to about 15% by weight alcohol, including all ranges subsumed therein. The preferred alcohol is a C 2 -C 6 alcohol and the most preferred alcohol used is ethanol. The balance of the reagent solution typically is water.
[0026] Subsequent to submerging the part in reagent solution, it is preferred to stir the solution in order to ensure efficient electrochemical oxidation. The part acts as the anode in the reaction and a cathode like, for example, graphite, copper, platinum, stainless steel or the like should be used in the process. Current is typically supplied with a conventional power supplier such as one made commercially available from suppliers like Agilent, Cole-Parmer or Omron. Typically, the electrochemical oxidation is carried out at a solution temperature from −10 to 35° C., and preferably, from −8 to 20° C., and most preferably, from −6 to 12° C., including all ranges subsumed therein. Current is typically from 0.05 to 1 amp, and preferably, from 0.07 to 0.5 amp, and most preferably, from 0.08 to about 0.2 amp, including all ranges subsumed therein. The voltage during the electrochemical oxidation typically should not exceed 200 volts. Preferably, the voltage is from about 50 to about 190 volts, and most preferably, from about 100 to about 180 volts, including all ranges subsumed therein. The electrochemical oxidation preferably runs for 0.05 to 2 hours, and preferably, from 0.5 to 2 hours, and most preferably, from 0.75 to 1.5 hours, including all ranges subsumed therein.
[0027] Subsequent to the electrochemical oxidation of the part, the same comprises a fabricated anodic aluminum oxide layer thereon.
[0028] In a preferred embodiment, the part, with the fabricated anodic aluminum oxide layer is subjected to an aluminum oxide removal step whereby the fabricated layer made is preferably removed via an oxidation layer removal step and then subjected to at least a second electrochemical oxidation step.
[0029] The oxidation layer removal step is limited only to the extent that it is one which removes, if not all, substantially all of the coating of fabricated anodic aluminum oxide previously made on the part and renders the part suitable for at least one additional electrochemical oxidation step. In a preferred embodiment, the oxidation layer removal step is achieved with an aqueous acidic solution comprising from about 2% to about 12%, and preferably, from about 2.5% to about 9%, and most preferably, from about 3% to about 7% by weight acid, including all ranges subsumed therein. Preferred acids suitable for use in such solutions to remove the coating in the oxidation layer removal step are phosphoric acid, sulfuric acid, hydrochloric acid or a mixture thereof. Most preferably, the acid used is phosphoric acid in an aqueous solution comprising from 3 to 7% by weight acid.
[0030] When removing the fabricated anodic aluminum oxide layer, the part is coated or sprayed with solution or preferably submerged in solution until substantially all fabricated layer is removed. Typically, this step is conducted for a period of 10 minutes to one (1) hour, and preferably, from 20 minutes to 45 minutes, including all ranges subsumed therein. The temperature at which the aluminum oxide layer is removed is typically from 50 to 80° C., and preferably, from 55 to 70° C., including all ranges subsumed therein.
[0031] Subsequent to removing the fabricated anodic aluminum oxide layer, the part is, again, subjected to at least one additional, and preferably, one additional electrochemical oxidation step. The additional electrochemical oxidation step is essentially a repeat of the first electrochemical oxidation step except that the reaction time is typically from 2.5 to 8, and preferably, from 3 to 7, and most preferably, from 3.5 to 5.5 hours, including all ranges subsumed therein. Subsequent to performing the additional or final electrochemical oxidation step on the panel, a final anodic aluminum oxide layer is fabricated thereon.
[0032] The final anodic aluminum oxide layer is porous and surprisingly uniform in nature, comprising holes or pores having diameters from 50 to 120 nm, and preferably, from 60 to 100 nm, and most preferably, from 70 to 90 nm, including all ranges subsumed therein. The depth of the pores after the final (i.e., preferably second) electrochemical step is typically from 2 to 10 microns, and preferably, from 3 to 8 microns, and most preferably from 4 to 6 microns, including all ranges subsumed therein. Furthermore, the interhole distance of the pores making up final anodic aluminum oxide layer is typically from about 200 to 500 nanometers, and preferably, from 300 to 475 nanometers, and most preferably, from 350 to 450 nanometers, including all ranges subsumed therein.
[0033] The part comprising the final anodic aluminum oxide layer may be etched in order to generate a preferred superhydrophobic panel with a superior array of nanoclusters. The etching may be achieved with an aqueous acidic solution like the one described to remove aluminum oxide in the oxidation layer removal step. The etching step is typically for about 2 to 7 hours, preferably, from 2.5 to 6 hours, and most preferably, from 3 to 5 hours, including all ranges subsumed therein. The temperature at which etching is conducted is typically from 20 to 50° C., and preferably, from 25 to 45° C., and most preferably, from 25 to 35° C., including all ranges subsumed therein.
[0034] The resulting frost-free and superhydrophobic part comprises nanoclusters of aluminum oxide whereby the nanoclusters are between 800 nm to 15 microns, and preferably, from 3 to 10 microns, and most preferably, from 4 to 7 microns in width, including all ranges subsumed therein. The height of the nanoclusters is from 700 nm to 10 microns, preferably, from 900 nm to 5 microns, and most preferably, from 1 to 4 microns, including all ranges subsumed therein. Such nanoclusters are typically from 10 to 40 microns apart (peak-to-peak) from each other, and preferably, 12 to 30 microns, and most preferably, 15 to 25 microns apart from each other, including all ranges subsumed therein.
[0035] Alternatively, the final anodic aluminum oxide layer may be coated with a laminate (i.e., hydrophobilizing agent) in lieu of being etched in order to generate a panel with preferred superhydrophobic properties. Such a laminate includes aero gels like those comprising a (halo) alkyltrialkoxysilicone (e.g., trifluoropropyltrimethoxysilicone) as well as coatings having polydimethylsiloxane. Others include (3-chloropropyl) trimethoxysilane and other art recognized polyhydroxy silanes. When applied, the laminate typically is less than 2 nm, and preferably, from 0.25 to 1.75 nm, and most preferably, from 0.75 to 1.5 nm, including all ranges subsumed therein. Application of the laminate is achieved by any art recognized technique, including techniques which include spraying, dipping and/or brushing steps followed by a drying step. Suppliers of such laminates include, for example, Microphase Coatings Inc., the Sherwin Williams Company, and Changzhou Wuzhou Chemical Co., Ltd.
[0036] In yet another alternative, the aluminum comprising part subjected to the method of this invention may originally comprise a flat aluminum oxide layer applied for or by an original equivalent manufacturer. Such a layer is typically 3 to 10 microns thick.
[0037] When the aluminum part selected for treatment according to this invention comprises an original aluminum oxide layer, the same is preferably subjected to one electrochemical oxidation under conditions consistent with what is described herein as the first electrochemical oxidation. Often, however, the electrochemical oxidation of parts with an original aluminum oxide layer is from 1 minute to 1.5 hours, and preferably, from 10 to 45 minutes, and most preferably, from 15 to 35 minutes, including all ranges subsumed therein. Typically, the electrochemical oxidation to the part comprising an original aluminum oxide layer adds an additional 2-12 microns, and preferably, 3 to 10 microns, and most preferably, 3.5 to 8.5 microns of fabricated anodic aluminum oxide layer. Such a layer comprises layered nanoclusters of aluminum oxide. These layered nanoclusters are similar in size to the nanoclusters described herein except that the layered nanoclusters are denser than the nanoclusters resulting from the etching of part originally having no aluminum oxide layer where denser means the layered nanoclusters are typically from 300 nm to 5 microns, and preferably, from 350 nm to 2 microns, and most preferably, from 400 to 600 nm apart, including all ranges subsumed therein. The layered nanoclusters are preferably coated with laminate in the manner previously described to produce another desired superhydrophobic and frost-free part.
[0038] The resulting frost-free parts made according to this invention typically have contact angles which are greater than 145°, and preferably, from 145 to 158°, and most preferably, from 146 to 155°, including all ranges subsumed therein.
[0039] Subsequent to generating the superhydrophobic parts described in this invention, the same may be returned to a device previously used or assembled into a new device.
[0040] In a most preferred embodiment, the parts described herein are panels for a freezer whereby the same do not display ice build-up and resist vapor condensation (i.e., are frost-free) even in the absence of energy requiring de-icing systems.
[0041] The following examples are provided to facilitate an understanding of the present invention. The examples are not intended to limit the scope of the claims.
Example 1
[0042] An aluminum panel (99.99% purity, 0.25 mm thickness about 26 cm 2 ) was degreased by submerging the panel in acetone and subjecting the same to ultrasonification for five (5) minutes. The aluminum panel was removed from the acetone and then rinsed in water. Aluminum anodization was preformed using a regulated and commercially available direct current power supply. A large glass beaker (2 L) and bath were used to maintain temperature. Anodization was performed in a H 3 PO 4 —H 2 O—C 2 H 5 OH (100 ml: 1000 ml: 200 ml) system at −5° C. The degreased aluminum panel was used as the anode and graphite was set as the cathode. The initial voltage was set at 160 V, and current was 0.1 mA. After anodization (electrochemical oxidation) for one hour, an aluminum oxidation layer was formed on the aluminum panel. The resulting oxidation layer was removed with 5% (wt) H 3 PO 4 at 60° C. for one hour. Subsequently, a second anodization was conducted on the aluminum panel following the same procedure as the initial anodization but for a period of four hours. Obtained was a panel comprising porous anodic aluminum oxide fabricated thereon with pores of uniform diameter (about 80 nm) and depth (about 5 microns).
[0043] The panel comprising porous anodic aluminum oxide was etched with 5% H 3 PO 4 at 30° C. to obtain the desired superhydrophobic surface. After etching for 3 hours and 40 minutes, the desired nanocluster surface was obtained (nanoclusters about 5 microns wide, about 3 microns in height and about 20 microns apart as determined using scanning election microscope imaging). The contact angle of this surface was tested against water using a commercially available goniometer. The contact angle of the surface was 150°.
[0044] To compare the hydrophobic properties of panels with different surfaces, ice adherence tests using air in a freezing environment were conducted. Pure aluminum panels, panels with porous alumina coatings and the panels made in this example were used. The pure aluminum panel was hydrophilic with a contact angle of 70°. The panel with porous alumina was also hydrophilic with a contact angle of 80°. The panel made according to this invention had a superhydrophobic surface with, again, a contact angle of 150°.
[0045] The panels were placed in a freezer (−20° C.) for 15 days. Any ice attachment was recorded. The hydrophilic aluminum panel and the hydrophilic panel with porous alumina visually displayed good affinity for ice build-up. In contrast, the panel treated according to this invention showed essentially no ice build-up. These comparisons indicate that the panels treated according to this invention, unexpectedly, have excellent ice-phobic/frost-free properties for freezer applications.
[0046] Another test was conducted to check the efficiency of ice build-up on the panels. Portions of the panels above were cut to the same shape (area of 1.61 cm 2 ). Before being put into a freezer, the samples were weighed. The weight of the aluminum panel, panel with porous alumina and the panel of this invention were 74.2, 69.0, and 58.4 mg, respectively. After being placed in a freezer (20° C.) for one month, the weights of these samples were measured to assess the amount of ice attachment on the surfaces of the panels. The weights were 101, 91, and 64 mg, respectively for the panels. Therefore, the amount of attached ice was 16.6, 13.7, and 3.6 mg/cm 2 on the aluminum panel, panel with porous alumina and panel made according to this invention, respectively. The amount of ice attached indicates that the panels made according to this invention unexpectedly have superhydrophobic surfaces that have ice-phobic properties.
Example 2
[0047] An embossed aluminum panel used and removed from a freezer (with a flat aluminum oxide layer of 6-8 microns) was degreased by ultrasonication in acetone for 5 minutes and rinsed in water. An electrochemical oxidation step was performed with a regulated direct current power supply. A large glass beaker (2 L) and a bath were used to maintain temperatures. Anodization was performed in a H 3 PO 4 —H 2 O—C 2 H 5 OH (100 ml: 1000 ml; 200 ml) system at 15° C. In the oxidation step, the embossed aluminum plate was used as the anode and graphite was set as the cathode. The initial voltage was set at 150 V, and current set at 0.1 mA. After anodization for 40 minutes, a fabricated anodic aluminum oxide layer comprising layered nanoclusters were formed (about 4.5 microns in height) on the surface of the plate. The nanoclusters were dense and about 500 nm apart.
[0048] A silicon comprising laminate (ethanol solution (5 m M) of C 3 H 7 S i (OCH 3 ) 3 ) was applied (about 1 nm) to the plate. The resulting panel with laminate was superhydrophobic and surprisingly displayed no ice attachment after being placed in a freezer for about one (1) week.
[0049] The results indicate that embossed aluminum panels from existing freezers may be treated according to this invention and returned to the freezer to yield a frost-free freezer.
Example 3
[0050] Panels similar to those obtained via the process described in Examples 1 and 2 were placed in a freezer (about 0° C.) for about 1 hour. Aluminum panels not treated according to this invention were also placed in the freezer under similar conditions. The panels were removed from the freezer and placed on the top of beakers containing hot (70° C.) water for 3 minutes. The panels were removed from the beakers and a visual examination surprisingly revealed significantly less vapor condensation on the panels treated according to this invention when compared to conventional aluminum panels having a contact angle of about 70° C.
Example 4
[0051] Ice adhesion forces of panels similar to the ones obtained via the processes described in Examples 1 and 2 were compared to the ice adhesion forces of untreated panels (contact angle about 70°). The apparatus employed was an SMS Texture Analyzer (TA-XT2). The panels used were cooled by passing the same through a channel of liquid nitrogen. Heat was also provided to control the temperature (0.1° C.) of the panels being tested. A Teflon® ring (15 mm diameter, 2 mm thick) was used to make a mock ice block. Wire and a cantilever on the texture analyzer were used to move the ring to create a shear force between ice in the ring and the panel. Prior to moving, 5 ml of water were dosed into the ring. The temperature of the plates was decreased within the range of −50° C. to −10° C. Once temperature was set, the resulting ice sample was kept stationary for about 3 minutes prior to being moved by the texture analyzer and force (N/cm 2 ) was assessed by moving the ice within the ring.
[0052] The results obtained indicate that the forces between the ice sample and panels treated according to this invention were between 35 and 100 percent less than the forces realized for the untreated aluminum panels, surprisingly indicating that the panels obtained according to this invention displayed excellent (i.e., low) ice adhesion results. | Frost-free surfaces and methods for manufacturing such surfaces are described. The frost-free surfaces reduce ice build-up, prevent vapor condensation and reduce adhesion force between ice and a solid substrate. The surfaces can be on parts used in devices where superhydrophobic properties may be obtained post or during device manufacturing. The superhydrophobic properties are the result of aluminum oxide clusters made on such surfaces. | 2 |
BACKGROUND
[0001] With the wide variety of software and hardware systems evolving and entering into business and personal usage, it becomes important to ensure that the user experience is as pleasant and productive as possible. For example, if a user experiences problems opening a web page, is it likely that the website vendor will not be able to convey the information desired whether for purely information purposes or to gain a customer through the sale of goods or services.
[0002] Code validation is a process of checking if code meets a certain criterion. In the context of web page code, for example, validation can be employed to ensure code interoperability with an open standard for interacting with a large population of potentially disparate software and/or hardware systems.
[0003] Business object properties should be validated before being persisted. For example, objects received from different callers such as APIs should be validated before passing the objects to a database or file system to ensure that data passed in association with of those objects is in the correct format. For example, for user objects of a first name and last name, it is desirable to not only ensure that the user has entered data into both fields, but also that the data entered is according to the desired format. Typical validation mechanisms handle properties related to null, maximum length, minimum length, and whether the properties match some criteria.
[0004] Adding validation code for each property using conventional methods is very cumbersome and error prone in that the developer writes code (or hard codes) into the application for properties that the developer wants to be validated. Developers (or users) expose the properties and manually assign criteria to the desired properties. Accordingly, where a large amount of code is involved, this process can be extremely time-consuming, inconsistent, and error-filled. Moreover, consider three fields (e.g., first name, last name, and phone number), if the user fails to enter data into the first field (a null condition), the validation process will throw an exception (or error), which is then processed back up to the user interface (UI) prompting the user to address the exception. When the user has corrected the error, validation is again performed on the first field, and if passed, validation processing moves to the second field, and so on. Thus, a large number of validations need to be performed before the object can be used. This is a very time-consuming ordeal that can impact not only the user experience but also system processes that are transparent to the user.
SUMMARY
[0005] The following presents a simplified summary in order to provide a basic understanding of novel embodiments described herein. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.
[0006] The disclosed architecture is a validation layer that facilitates the automatic annotation of object properties of the object with a validation attribute (e.g., FieldValidation), thereby specifying a set of validation rules declaratively and scenarios under which these validation rules should fire.
[0007] During build time, the validation layer iterates through each module and associated module classes to automatically generate the validation code. This not only makes the code more readable, but also ensures that a project has consistent validation handling. The validation layer applies to the annotation and validation at the property-level and inter-property. Thus, property-level validation is employed to ensure the correctness of individual values, and inter-property validation can be employed to ensure the correctness in combinations of values.
[0008] To the accomplishment of the foregoing and related ends, certain illustrative aspects are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles disclosed herein can be employed and is intended to include all such aspects and their equivalents. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a computer-implemented system that facilitates data validation.
[0010] FIG. 2 illustrates an alternative system that employs validation according to system layers.
[0011] FIG. 3 illustrates a general diagram of property annotation for objects of an application module.
[0012] FIG. 4 illustrates a method of validation processing.
[0013] FIG. 5 illustrates an alternative method of validation processing.
[0014] FIG. 6 illustrates a method of validation processing for related property consistency.
[0015] FIG. 7 illustrates a block diagram of a computing system operable to execute validation processing in accordance with the disclosed architecture.
[0016] FIG. 8 illustrates a schematic block diagram of an exemplary computing environment that validation processing in a client/server environment.
DETAILED DESCRIPTION
[0017] The disclosed architecture is a validation layer that is employed between an application layer and a storage layer for the interception of write operations of data to a database or file system. Using this validation layer, an object can annotate object properties with a validation attribute to declaratively specify a set of validation rules, and the scenarios under which these validation rules should be utilized. During build time, the validation layer then iterates through each object module and the associated object classes, and automatically generates validation code.
[0018] Reference is now made to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. It may be evident, however, that the novel embodiments can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate a description thereof.
[0019] Referring initially to the drawings, FIG. 1 illustrates a computer-implemented system 100 that facilitates data validation. The system 100 includes an interception component 102 for intercepting a write operation of a data object 104 to a data store 106 (or file system). The write operation can occur after a user enters the desired information or string into a field (e.g., a web page). An attribute component 108 automatically tags the data object 104 with a validation attribute. A build component 110 then automatically generates validation code at build time based on the attribute. The validation code can then be processed for exceptions, and the exceptions corrected before the data object is persisted.
[0020] FIG. 2 illustrates an alternative system 200 that employs validation according to system layers. The system 200 includes an application layer 202 via which one or more objects 204 (denoted DATA OBJECT 1 , . . . ,DATA OBJECT N , where N is a positive integer) are created and utilized. In accordance with the disclosed architecture, a validation layer 206 is introduced that intercepts write operations from the application layer 202 to a storage layer 208 (e.g., associated with the data store 106 of FIG. 1 ). The validation layer 206 then processes the data objects as described supra in accordance with the interception component 102 , attribute component 108 , and build component 110 . Accordingly, validation is performed at the object level.
[0021] FIG. 3 illustrates a general diagram 300 of property annotation for objects 302 of an application module 304 . The module 304 at the application layer 202 can include one or more objects 302 , some of which have associated properties. For example, a first object (OBJECT 1 ) has object properties (denoted OBPROP 11 ,OBPROP 12 , . . . ). Similarly, a second object can include object properties (denoted OBPROP 21 ,OBPROP 22 , . . . ). A third object (OBJECT 3 ) has no properties but can still be tagged for validation.
[0022] Annotation of one or more of the objects 302 can occur at the application layer 202 . Here, the first object 308 and third object 310 are annotated with a ValAttrib for validation processing, but the second object 312 is not annotated. In another implementation, all of the objects 302 are automatically annotated for validation processing.
[0023] When the objects 302 and associated data are to be persisted, the validation layer 206 intercepts the write process and iterates through each module and the module classes, and generates the validation code. Accordingly, at build time, the annotated objects ( 308 and 310 ) and properties are processed into rules 314 . The rules are then processed and exceptions generated, where necessary. Once all exceptions have been cleared, the objects can be persisted.
[0024] Following is exemplary code that illustrates the annotation and validation processes described herein. Consider a project that wants to use the services of the validation layer includes a Validation Helper DLL (dynamic link library). The Helper DLL implements a custom attribute called FieldValidationAttribute. Classes then apply the above attribute and implement an ICustomValidator interface to enforce validation rules.
[0000]
public class Address : ICustomValidator
{
[FieldValidation(MaxLength = 16)]
public string AddressId
{
get {return addressId ;}
set {addressId=value;}
}
[FieldValidation(IsRequiredForInsert = true,
IsRequiredForUpdate = true, MaxLength = 64)]
public string FriendlyName
{
get {return friendlyName;}
set {friendlyName=value;}
}
[FieldValidation(IsRequiredForInsert = true,
IsRequiredForUpdate = true, MaxLength = 128)]
[FieldValidation(MinLenth=6)]
public string Street1
{
get {return street1;}
set { street1=value;}
}
.....
public EcommerceErrorCollection CustomValidate(bool isCreate,
string providerName)
{
}
}
[0025] In the example above, a new class called Address is defined. A field validation attribute FieldValidation is applied to MaxLength=16; thus, a user passing this field will be limited to 16 units. Accordingly, when inputting information into a database where the database expects data no longer than 16 units, the validation layer will check this prior to the data reaching the database. As shown above, FieldValidation is assigned to IsRequiredForInsert=true, and other object properties. Because these properties are annotated, insertion of this object into a database can only be accomplished when the fields are there.
[0026] During the build process, validation code is generated for classes that annotate properties with FieldValidation validation attribute. The auto-generated class as follows:
[0000]
public class AddressInfoValidator : IValidator
{
public EcommerceErrorCollection Validate( object profile,
bool isCreate, string providerName)
{
Microsoft.OfficeLive.ECommerce.AccountManagement.AddressInfo
source =
(Microsoft.OfficeLive.ECommerce.AccountManagement.
AddressInfo)profile;
EcommerceErrorCollection validationErrors = new
EcommerceErrorCollection( );
ValidationClass.Instance.ValidateMaxLength(source.AddressId,16,
“AddressId”, ref validationErrors);
ValidationClass.Instance.ValidateRequiredForInsertFieldValiation
(source.FriendlyName, “FriendlyName”, isCreate,ref validationErrors);
ValidationClass.Instance.ValidateRequiredForUpdateField-
Valiation(source.FriendlyName, “FriendlyName”, !isCreate,ref
validationErrors);
ValidationClass.Instance.ValidateMaxLength(source.FriendlyName,
64,“FriendlyName”, ref validationErrors);
ValidationClass.Instance.ValidateRequiredForInsertField-
Valiation(source.Street1,“Street1”, isCreate,ref validationErrors);
ValidationClass.Instance.ValidateRequiredForUpdateField-
Valiation(source.Street1,“Street1”, !isCreate,ref validationErrors);
ValidationClass.Instance.ValidateMaxLength(source.Street1,128,“
Street1”, ref validationErrors);
ValidationClass.Instance.ValidateCustomValidation(profile,
isCreate, providerName, ref validationErrors);
return validationErrors;
}
}
[0027] Before persisting the objects, the user can call an API from the Validation Helper DLL, ValidateProfile, for example, as illustrated by the following exemplary code:
[0000]
static public void ValidateProfile(IProfileType profile, bool
isCreate, string profileproviderName)
[0028] The above API executes all of the business rules and throws exceptions for validation failures.
[0029] FIG. 4 illustrates a method of validation processing. While, for purposes of simplicity of explanation, the one or more methodologies shown herein, for example, in the form of a flow chart or flow diagram, are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation.
[0030] At 400 , an object is received for persistence or file processing. At 402 , an object property of the object is annotated for validation processing. At 404 , a set of validation rules are specified based on the annotated property. At 406 , validation code is automatically generated at build time based on the annotated object property.
[0031] FIG. 5 illustrates an alternative method of validation processing. At 500 , a module of objects and object properties is received. At 502 , the desired objects are annotated (or tagged with a validation tag). At 504 , a write process is initiated for storing the module and/or module objects (and data). At 506 , the write process is intercepted and build-time validation initiated. At 508 , the system automatically iterates through the module classes. At 510 , validation rules are generated from the iteration process. At 512 , the rules are then processed, and exceptions thrown (or errors generated) for a user to clear. At 514 , the module is persisted once the user has cleared all exceptions.
[0032] FIG. 6 illustrates a method of validation processing for related property consistency. At 600 , a module of objects and object properties is received. At 602 , the objects are automatically annotated for validation. At 604 , a write process is intercepted and build-time validation begins. At 606 , validation rules are generated from the annotated properties. At 608 , the rules are processed for consistencies or inconsistencies between related properties. In other words, if a field requires entry of a city, entry of the state data should be consistent with the city. This can be carried further to also check for consistency with a zip code, and/or an address, for example. At 610 , errors are generated based on the inconsistencies, and presented to a user. Note that the user can be a human perceiving the errors via a UI, or another system process to which the errors are sent for processing. At 612 , the errors are cleared before the data is persisted to a data store.
[0033] As used in this application, the terms “component” and “system” are intended to refer to a computer-related entity, either hardware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, a hard disk drive, multiple storage drives (of optical and/or magnetic storage medium), an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and/or thread of execution, and a component can be localized on one computer and/or distributed between two or more computers.
[0034] Referring now to FIG. 7 , there is illustrated a block diagram of a computing system 700 operable to execute validation processing in accordance with the disclosed architecture. In order to provide additional context for various aspects thereof, FIG. 7 and the following discussion are intended to provide a brief, general description of a suitable computing system 700 in which the various aspects can be implemented. While the description above is in the general context of computer-executable instructions that may run on one or more computers, those skilled in the art will recognize that a novel embodiment also can be implemented in combination with other program modules and/or as a combination of hardware and software.
[0035] Generally, program modules include routines, programs, components, data structures, etc., that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the inventive methods can be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, minicomputers, mainframe computers, as well as personal computers, hand-held computing devices, microprocessor-based or programmable consumer electronics, and the like, each of which can be operatively coupled to one or more associated devices.
[0036] The illustrated aspects may also be practiced in distributed computing environments where certain tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules can be located in both local and remote memory storage devices.
[0037] A computer typically includes a variety of computer-readable media. Computer-readable media can be any available media that can be accessed by the computer and includes volatile and non-volatile media, removable and non-removable media. By way of example, and not limitation, computer-readable media can comprise computer storage media and communication media. Computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital video disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computer.
[0038] With reference again to FIG. 7 , the exemplary computing system 700 for implementing various aspects includes a computer 702 , the computer 702 including a processing unit 704 , a system memory 706 and a system bus 708 . The system bus 708 provides an interface for system components including, but not limited to, the system memory 706 to the processing unit 704 . The processing unit 704 can be any of various commercially available processors. Dual microprocessors and other multi-processor architectures may also be employed as the processing unit 704 .
[0039] The system bus 708 can be any of several types of bus structure that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. The system memory 706 includes read-only memory (ROM) 710 and random access memory (RAM) 712 . A basic input/output system (BIOS) is stored in a non-volatile memory 710 such as ROM, EPROM, EEPROM, which BIOS contains the basic routines that help to transfer information between elements within the computer 702 , such as during start-up. The RAM 712 can also include a high-speed RAM such as static RAM for caching data.
[0040] The computer 702 further includes an internal hard disk drive (HDD) 714 (e.g., EIDE, SATA), which internal hard disk drive 714 may also be configured for external use in a suitable chassis (not shown), a magnetic floppy disk drive (FDD) 716 , (e.g., to read from or write to a removable diskette 718 ) and an optical disk drive 720 , (e.g., reading a CD-ROM disk 722 or, to read from or write to other high capacity optical media such as the DVD). The hard disk drive 714 , magnetic disk drive 716 and optical disk drive 720 can be connected to the system bus 708 by a hard disk drive interface 724 , a magnetic disk drive interface 726 and an optical drive interface 728 , respectively. The interface 724 for external drive implementations includes at least one or both of Universal Serial Bus (USB) and IEEE 1394 interface technologies.
[0041] The drives and their associated computer-readable media provide nonvolatile storage of data, data structures, computer-executable instructions, and so forth. For the computer 702 , the drives and media accommodate the storage of any data in a suitable digital format. Although the description of computer-readable media above refers to a HDD, a removable magnetic diskette, and a removable optical media such as a CD or DVD, it should be appreciated by those skilled in the art that other types of media which are readable by a computer, such as zip drives, magnetic cassettes, flash memory cards, cartridges, and the like, may also be used in the exemplary operating environment, and further, that any such media may contain computer-executable instructions for performing novel methods of the disclosed architecture.
[0042] A number of program modules can be stored in the drives and RAM 712 , including an operating system 730 , one or more application programs 732 , other program modules 734 and program data 736 . All or portions of the operating system, applications, modules, and/or data can also be cached in the RAM 712 . It is to be appreciated that the disclosed architecture can be implemented with various commercially available operating systems or combinations of operating systems.
[0043] The modules 734 can include the interception component 102 for intercepting a write process, the attribute component 108 for tagging objects and/or object properties, and the build component 110 for the processing of the validation rules at build time.
[0044] A user can enter commands and information into the computer 702 through one or more wired/wireless input devices, for example, a keyboard 738 and a pointing device, such as a mouse 740 . Other input devices (not shown) may include a microphone, an IR remote control, a joystick, a game pad, a stylus pen, touch screen, or the like. These and other input devices are often connected to the processing unit 704 through an input device interface 742 that is coupled to the system bus 708 , but can be connected by other interfaces, such as a parallel port, an IEEE 1394 serial port, a game port, a USB port, an IR interface, etc.
[0045] A monitor 744 or other type of display device is also connected to the system bus 708 via an interface, such as a video adapter 746 . In addition to the monitor 744 , a computer typically includes other peripheral output devices (not shown), such as speakers, printers, etc.
[0046] The computer 702 may operate in a networked environment using logical connections via wired and/or wireless communications to one or more remote computers, such as a remote computer(s) 748 . The remote computer(s) 748 can be a workstation, a server computer, a router, a personal computer, portable computer, microprocessor-based entertainment appliance, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer 702 , although, for purposes of brevity, only a memory/storage device 750 is illustrated. The logical connections depicted include wired/wireless connectivity to a local area network (LAN) 752 and/or larger networks, for example, a wide area network (WAN) 754 . Such LAN and WAN networking environments are commonplace in offices and companies, and facilitate enterprise-wide computer networks, such as intranets, all of which may connect to a global communications network, for example, the Internet.
[0047] When used in a LAN networking environment, the computer 702 is connected to the local network 752 through a wired and/or wireless communication network interface or adapter 756 . The adaptor 756 may facilitate wired or wireless communication to the LAN 752 , which may also include a wireless access point disposed thereon for communicating with the wireless adaptor 756 .
[0048] When used in a WAN networking environment, the computer 702 can include a modem 758 , or is connected to a communications server on the WAN 754 , or has other means for establishing communications over the WAN 754 , such as by way of the Internet. The modem 758 , which can be internal or external and a wired or wireless device, is connected to the system bus 708 via the serial port interface 742 . In a networked environment, program modules depicted relative to the computer 702 , or portions thereof, can be stored in the remote memory/storage device 750 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers can be used.
[0049] The computer 702 is operable to communicate with any wireless devices or entities operatively disposed in wireless communication, for example, a printer, scanner, desktop and/or portable computer, portable data assistant, communications satellite, any piece of equipment or location associated with a wirelessly detectable tag (e.g., a kiosk, news stand, restroom), and telephone. This includes at least Wi-Fi and Bluetooth™ wireless technologies. Thus, the communication can be a predefined structure as with a conventional network or simply an ad hoc communication between at least two devices.
[0050] Referring now to FIG. 8 , there is illustrated a schematic block diagram of an exemplary computing environment 800 that validation processing in a client/server environment. The system 800 includes one or more client(s) 802 . The client(s) 802 can be hardware and/or software (e.g., threads, processes, computing devices). The client(s) 802 can house cookie(s) and/or associated contextual information, for example.
[0051] The system 800 also includes one or more server(s) 804 . The server(s) 804 can also be hardware and/or software (e.g., threads, processes, computing devices). The servers 804 can house threads to perform transformations by employing the architecture, for example. One possible communication between a client 802 and a server 804 can be in the form of a data packet adapted to be transmitted between two or more computer processes. The data packet may include a cookie and/or associated contextual information, for example. The system 800 includes a communication framework 806 (e.g., a global communication network such as the Internet) that can be employed to facilitate communications between the client(s) 802 and the server(s) 804 .
[0052] Communications can be facilitated via a wired (including optical fiber) and/or wireless technology. The client(s) 802 are operatively connected to one or more client data store(s) 808 that can be employed to store information local to the client(s) 802 (e.g., cookie(s) and/or associated contextual information). Similarly, the server(s) 804 are operatively connected to one or more server data store(s) 810 that can be employed to store information local to the servers 804 .
[0053] The clients 802 can include the application modules having object and object properties which can be persisted to the client data stores 808 . Alternatively, or in combination therewith, the validation processing can be in preparation for storing data of the client on the server data stores 810 .
[0054] What has been described above includes examples of the disclosed architecture. It is, of course, not possible to describe every conceivable combination of components and/or methodologies, but one of ordinary skill in the art may recognize that many further combinations and permutations are possible. Accordingly, the novel architecture is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. | A validation layer that facilitates the automatic annotation of object properties by the object with a validation attribute (e.g., FieldValidation), thereby specifying a set of validation rules declaratively, and scenarios under which these validation rules should fire. During build time, the validation layer iterates through each module and associated module classes to automatically generate the validation code. This not only makes the code more readable, but also ensures that a project has consistent validation handling. The validation layer applies to the annotation and validation at the property-level and inter-property. Thus, property-level validation is employed to ensure the correctness of individual values, and inter-property validation can be employed to ensure the correctness in combinations of values. | 6 |
[0001] This application claims Paris Convention priority of DE 10 2006 037 196.8 filed Aug. 9, 2006 the complete disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The invention concerns a magnetic resonance (MR) detection configuration comprising at least one RF resonant circuit with an inductance, a preamplifier module, and an RF receiver, wherein a reactive transformation circuit is connected between a high-ohmic point of the inductance of the RF resonant circuit and a low-ohmic connecting point of the RF resonant circuit to act as an impedance transformer, and wherein the low-ohmic connecting point of the RF resonant circuit is connected to the preamplifier module via an RF line having a characteristic impedance.
[0003] A configuration of this type is disclosed in [4].
[0004] A sensor of an NMR spectrometer consists essentially of one radio frequency (RF) resonant circuit which is disposed closely around an NMR test sample. The RF resonant circuit normally functions as a transmitting antenna in a first time period, the so-called transmitting process. A strong pulse-shaped RF current is supplied to the RF resonant circuit, which generates a strong RF field in the NMR test sample and excites the nuclear spins contained therein. In a subsequent second time period, the so-called receiving process, the RF resonant circuit functions as a detector and receives the RF field radiated by the nuclear spins, the so-called FID signal (FID =free induction decay) which is supplied to the preamplifier and its matching network via an RF line.
[0005] In order to optimize the signal-to-noise ratio (=SINO) of the nuclear magnetic resonance signal (NMR signal), noise matching of the preamplifier to the RF line must be obtained. One end of the RF line which extends to the preamplifier may thereby not be terminated with the characteristic impedance of the RF line, which could cause standing waves to be generated in the RF line [4] during the receiving process. These influence the Q value and the resonance frequency of the loaded RF resonant circuit, such that the RF line and the matching network of the preamplifier must also be regarded as parts of the RF resonant circuit.
[0006] In order to obtain a high signal sensitivity, i.e. a high SINO of the FID signal, during the receiving process, the series loss resistance of the inductance of the RF resonant circuit must i.a. be minimum in order to also minimize the thermal noise produced therein. For this reason, cryogenically cooled RF resonant circuits of normally conducting materials and also of high temperature super conductor (HTSC) materials are used. This substantially reduces the noise and at the same time considerably increases the Q value of the unloaded RF resonant circuit (resonant circuit without cable and matching network).
[0007] However, RF resonant circuits with high Q values are disadvantageous in that, during the transmitting process, the pulse-shaped transmission energy cannot be immediately received by the RF resonant circuit or be removed therefrom, since the RF resonant circuit requires both a certain build-up time as well as decay time, which are longer the higher the Q value. A power-matched resonant circuit has twice the damping factor or half the time constant compared to a freely oscillating resonant circuit. This is easy to demonstrate. This double damping usually determines the build-up and decay behavior of the resonant circuit. This is, however, not sufficient e.g. for NMR spectroscopy applications.
[0008] The decay process is mostly critical, since it usually covers the start of the receiving process and thereby also the start of the FID signal, thereby preventing exact temporal separation between the transmission and receiving processes. For this reason, a third time period is suitably defined between the transmission and receiving process (called damping process below).
[0009] Additional complications result from the fact that modern NMR magnet systems have superconducting coils. For this reason, the space within the room temperature bore (RT bore), i.e. within the measuring space available, is very confined. In consequence thereof, the RF resonant circuit must be spatially separated from the preamplifier and be electrically connected to an RF line. Due to the high NMR frequencies of today's spectrometers, the length of this RF line may be a multiple of the wavelength of the NMR frequency. Depending on the construction and the NMR frequency, the RF line may, however, also be very short compared to the wavelength.
[0010] The problems, configurations and properties that occur in the three defined time periods are described below. In particular, the problems associated with RF resonant circuits having very high Q values are discussed.
[0011] During transmission, the width of the NMR spectrum that can be excited is limited by the available bandwidth of the transmission system and thereby, in particular, by the bandwidth of the RF resonant circuit used for transmission. A very high Q value of the RF resonant circuit may cause the bandwidth of the RF resonant circuit to be too small to excite the desired frequency range of the magnetic spins. Means must be found to nevertheless obtain the required excitation bandwidths of the NMR spectrum.
[0012] During damping, additional measures must be taken in order to maximally reduce the exponentially decaying process of the coil current in response to the transmission pulse, such that reception of the FID signal can be started as quickly as possible. This is very important, since the start of the FID signal contains i.a. very important information about the initial phase of the individual resonance frequencies which are contained in the FID signal. When this information is lost, the base line and the shape of the NMR resonance lines will be distorted in the NMR spectrum obtained after Fourier transformation (FT), and moreover the integral over the individual NMR lines can no longer be correctly calculated.
[0013] In addition to distortions in the spectrum, a long decay process also produces an undesired SINO loss, since no FID signal can be acquired during the decay process, i.e. part of the FID signal is lost.
[0014] The extent to which the decay process must have vanished before the receiving process can be started depends mainly on the preamplifier and the subsequent detection circuit. These must work in the linear region of their characteristic dependencies, i.e. must not be saturated. Acquisition of the FID signal may not be started before this condition is met.
[0015] The receiving process is a very complex process that substantially involves three problems:
[0016] 1. The problem of radiation damping. This occurs when the spin concentration of the solvent or the test substance is very high. The integrating effect of the numerous magnetic spins in the test sample may be compared with a resonant circuit which is strongly electromagnetically coupled to the RF resonant circuit. In this case, the RF resonant circuit may react to this “resonant circuit”, which can cause broadenings, distortions and phase errors of the spectral lines.
[0017] When two resonant circuits are provided which are disposed at a certain separation from each other, their electromagnetic coupling and thereby their mutual influence increases, the larger the Q values of the individual resonant circuits. The situation for radiation damping is similar, with one resonant circuit being defined by the magnetic spins and the other by the RF resonant circuit. The first resonant circuit has a very high intrinsic effective Q value due to the properties of the magnetic spins. This Q value may be between 10 6 and 10 9 . For this reason, the height of the Q value of the second resonant circuit, i.e. the RF resonant circuit, is important for observation of the coupling. This view is equivalent to the observation that, with a high Q value of the RF resonant circuit, large currents flow therein in response to the NMR signals, which again acts on the spins depending on the phase of the resonator current. In order to minimize radiation damping, this Q value should be minimum without thereby deteriorating the SINO.
[0018] 2. The decay signal of the resonator in response to the transmission pulse is greatly reduced after damping but still has a residual portion that can cause distortions of the base line in the NMR spectrum. For this reason, it is important to also damp the RF resonant circuit during the receiving process. The time constant of the decay signal during the receiving process is thereby called ι EV . The damping value that can be obtained during the receiving process is naturally smaller (i.e. the time constant is longer) than that during the damping process, since the circuit must be optimized primarily to an optimum SINO and not to optimum damping.
[0019] 3. The third problem is caused when the Q value of the RF resonant circuit during the receiving process is too high for receiving the entire width of the desired NMR spectrum. Precise damping of the RF resonant circuit during the receiving process provides adjustment of the spectral receiving range of the RF resonant circuit to the width of the desired NMR spectrum. Such damping during the receiving process is only reasonable when the RF resonant circuit is also additionally damped during the transmission process, such that it yields the desired excitation bandwidth. The latter should be larger or equal to the width of the desired NMR spectrum.
[0020] It is important that damping of the RF resonant circuit does not deteriorate the SINO during the receiving process, which may seem contradictory at first, but can be addressed using so-called “electronic damping”. Damping of the RF resonant circuit is obtained by the electronic input impedance of the preamplifier [2]-[4]. The adjustment network of the preamplifier itself should, however, be noise-matched, i.e. the preamplifier itself should see optimum source impedance (the optimum source impedance is that source impedance that produces the highest SINO) downstream of its adjustment circuit.
[0021] In [1], the Q value of an RF resonant circuit 100 ′ is kept small during the transmission and damping process using a so-called “Q switch” ( FIGS. 11 a , 11 b ). The name already indicates that a resistance R Q is added to the RF resonant circuit 100 ′ using a switch 11 . The resistance R Q and the switch 11 are connected in series and connected between the high-impedance point M of inductance L of the RF resonant circuit 100 ′ and ground. The resistance R Q damps the RF resonant circuit 100 ′, thereby reducing its Q value. The switch 11 is realized in most cases using a PIN diode D Q ( FIG. 11 b ). However, switches with field effect transistors (FET) are also feasible. The PIN diode D Q Is blocked with a high voltage HV which is applied in the reverse direction, or brought into a conducting state using a current I 11 BIAS in the forward direction.
[0022] This configuration is disadvantageous in that the additional components (resistance R Q , PIN diode D Q etc.) must be housed in the vicinity of the sensitive RF resonant circuit and can thereby deteriorate the homogeneity of the static magnetic field due to their magnetic susceptibility. Additionally, a control signal must be guided in the very sensitive region of the RF resonant circuit. Additional wiring of the RF resonant circuit unavoidably reduces the Q value during the receiving process and thereby produces an undesired SINO loss. The parallel loss resistance of the PIN diode D Q in the blocked state is sufficient to cause this loss.
[0023] Moreover, the PIN diode D Q of cryogenically cooled RF resonant circuits should also be cooled. This is possible only to a limited degree due to the “carrier-freeze-out-effect” in semiconductors, which is very problematic.
[0024] The Q switch cannot be directly used for damping the RF resonant circuit during the receiving process, since it would cause an excessive SINO loss. Special methods have been developed with which the Q switch is intermittently used, i.e. is switched on temporarily within a time interval between two data points and subsequently switched off again prior to detection of the next data point. This method also produces a SINO loss, since there is less time for data acquisition.
[0025] The configuration used in [2] consists of an RF resonant circuit and a preamplifier which are located close to each other and therefore need not be connected to each other via an RF line. The preamplifier is negative feedbacked and thereby generates an input impedance which depends on the size of the feedback. This input impedance is used as a damping impedance for the RF resonant circuit during the receiving process and is directly connected to the high-impedance point of the RF resonant circuit. Since the damping impedance is generated electronically by active elements, this type of damping is also called “electronic damping”. In the conventional circuit, two separate couplings to the RF resonant circuit are used: the first for the transmission process and the second for the damping and receiving processes. Both couplings are provided at the high-impedance point of the RF resonant circuit. During the transmission process, the RF resonant circuit is damped by normal power matching.
[0026] During the decay time of the RF resonant circuit (damping process), the latter practically remains undamped throughout the entire time, since the electronic damping effect is cancelled by limiting diodes for safety reasons, as is explained below. It is only at the very end of the decay time, that the electronic damping again becomes effective, but can no longer cause any significant reduction of the overall time of the decay process.
[0027] The preamplifier is optimally noise-matched during the receiving process. When the quotient between the magnitude of the input impedance and the magnitude of optimum source impedance of the preamplifier differs greatly from 1, the RF resonant circuit can also be damped without any SINO loss. The RF resonant circuit is additionally loaded by the two adjustment paths during the transmission and receiving process, which nevertheless finally produces a SINO loss, mainly when the Q values of the RF resonant circuit are very high.
[0028] Today's preamplifiers usually require limiting diodes at the input, which should protect against overloading during the transmission process. These act more or less like low-ohmic voltage sources of approximately 2 V and thereby prevent the occurrence of excessive voltages at the sensitive input of the preamplifier during the transmission pulse and the subsequent decay process. In consequence thereof, the electronic damping by the input impedance of the preamplifier becomes active and provides its damping effect only when the preamplifier with limiting diodes is operating in a linear range. The main portion of the decay process is therefore not additionally damped in the present configuration, which operates only with an electronic impedance as damping means, and the coil energy dies down with the undamped time constant.
[0029] Moreover, in current NMR spectrometers comprising high field superconducting magnets, it is practically not possible to closely arrange the RF resonant circuit and preamplifier, since there is no space for the preamplifier in the direct vicinity of the RF resonant circuit. The magnetic field strength of the NMR magnet is also too high for unproblematic function of the preamplifier and moreover cryogenically cooled RF resonant circuits and preamplifiers require different cryogenic temperatures for optimum operation, i.e. both units would have to be thermally insulated from each other, which, in turn, would cause space problems.
[0030] Additionally, the above-described feedback of the preamplifier practically cannot be realized in today's high field systems for reasons of stability. The associated high NMR frequencies e.g. in a 900 MHz NMR spectrometer the feedback of the preamplifier may produce a strong oscillation tendency which can be eliminated only with great effort, if at all.
[0031] For all above-mentioned reasons, the configuration disclosed in [2] is not suitable for today's high field NMR spectrometers.
[0032] [3] Discloses a configuration that comprises an RF resonant circuit and a preamplifier which are also disposed close to each other. It mentions the possibility of spatial separation of both objects and connecting them via an RF line, but does not mention the associated problems (treatment of optimum damping under the limitation that results from adjustment to the line of impedance R W ). As in the configuration of [2], the configuration of [3] also achieves electronic damping of the RF resonant circuit using the input impedance of the active part of the preamplifier (without matching network), wherein this damping causes no loss in optimum SINO and is stronger the more the ratio between the input impedance and the optimum noise impedance of the preamplifier differs from 1 (overcoupling). The RF resonant circuit is coupled at the low-impedance point A of the RF resonant circuit. Different types of impedance transformation between point A and the high-impedance point M of the RF resonant circuit are proposed and examined in view of the SINO.
[0033] In the configuration of [3], the decay time is reduced by 30 %. This is, however, far too little for today's high field systems. Rather, reductions of approximately 90 % are desired. Moreover, with large “overcoupling”, undesired effects occur, e.g. saturation effects in the preamplifier and the decay times can increase again. The decay process may even contain two frequency components whose envelope decays very slowly.
[0034] The configuration disclosed in [4] also comprises one RF resonant circuit 100 and a preamplifier module 2 which are, however, positioned at a separation from each other and are connected via an RF line 15 ( FIG. 10 ). The RF resonant circuit 100 comprises an inductance L and a loss resistance R S and is connected at a low-impedance connecting point A to a preamplifier module 2 via the RF line 15 of line impedance R W , which comprises a preamplifier 5 with an matching network AN and with the active part 5 ′ of the preamplifier.
[0035] In order to maintain the SINO, the impedance transformation of the loss resistance R S of the inductance L of the RF resonant circuit 100 relative to a point V between the matching network AN and the input of the active part 5 ′ of the preamplifier 5 must produce an impedance value which is equal to the optimum source impedance of the active part of the preamplifier 5 ′. When this condition is met, and when the ratio between the magnitudes of the optimum source impedance and the input impedance of the active part of the preamplifier 5 ′ differs greatly from 1, the transform of the input impedance of the preamplifier 5 relative to the low-impedance connecting point A of the RF resonant circuit 100 differs greatly from the line impedance R W of the RF line 15 between the RF resonant circuit 100 and the preamplifier module 2 and thereby provides much stronger damping of the RF resonant circuit 100 compared to conventional power matching.
[0036] The impedance transformation between the RF resonant circuit 100 and the preamplifier 5 is performed such that, in a first step, the loss resistance R S of the inductance L of the RF resonant circuit 100 is transformed to a value R A at the low ohmic connecting point A using a coupling capacitor. R A is usually equal to R W . The RF line 15 which has the impedance R W is thereby matched at the low ohmic connecting point A without reflection such that the loss in the RF line is reduced.
[0037] When viewing from point B, disposed at the end of the RF line 15 facing away from the RF resonant circuit, towards the line 15 , the resistance value R W appears. It is transformed in a second step by means of the matching network AN such that the active part of the preamplifier 5 ′ sees the optimum source impedance at point V.
[0038] [4] thus describes extensive measures for reducing radiation damping during the receiving process. These measures may also have a strong damping effect on the RF resonant circuit during the receiving process without producing a SINO loss. Coupling to the RF resonant circuit is effected at the low impedance connecting point A of the RF resonant circuit. Optimum damping of the RF resonant circuit during the receiving process and the produced advantages for decay of the RF resonant circuit is, however, not mentioned.
[0039] The Q value of the RF resonant circuit plays a central role in the design of a transmitting/receiving system for NMR and for this reason there is great need for a method that optimally reduces the disturbing influences of the high Q value of the RF resonant circuit during the transmission, damping and receiving process, wherein the SINO must not decrease during the receiving process.
[0040] The above-described prior art only provides solutions with electronic damping impedances (input impedances of preamplifiers) for the damping process and when damping is performed at the low impedance point A of the RF resonant circuit, which do not optimally damp the RF resonant circuit due to their non-linear properties, since damping acts, in particular, only when the amplitude of the oscillation has become sufficiently small that it is in the linear range of the preamplifier. Towards this end, it must have largely decayed already. Thus, most of the time passes without damping.
[0041] The conventional proposed solutions merely present individual solutions which are either optimized for the transmission and damping process or for the receiving process, but do not provide a comprehensive solution that provides optimum relationships in all three processes.
[0042] It is therefore the underlying purpose of the invention to provide an MR detection configuration, wherein the RF resonant circuit and the preamplifier module are spatially separated from each other, comprising an extensive damping concept, wherein all three processes (transmitting, damping and receiving process) are optimized.
SUMMARY OF THE INVENTION
[0043] This object is achieved in accordance with the invention in that at least one passive damping impedance is provided in the preamplifier module downstream of the RF line, wherein the passive damping impedance can be switched to the resonant circuit during a damping and/or transmission process, wherein one RF transmitter transmits RF pulses to the RF resonant circuit for exiting a spin system using a switching means, and wherein the respective amount of the complex reflection factor of the passive damping impedance relative to the impedance of the RF line exceeds a value of 0.5.
[0044] Passive damping impedance means an impedance which is realized through one or more passive components or a passive circuit.
[0045] The passive damping impedances are parts of a damping path or a transmitting path, wherein the transmitting path connects the switching means to the RF transmitter during transmission, and the damping path connects the switching means to a damping impedance during damping. Moreover, a receiving path is provided which connects the switching means to the preamplifier during the receiving process. Using the switching means of the inventive device, the RF resonant circuit can optionally be connected to the damping path and the associated damping impedance, to the transmission path and the associated damping impedance, or to a receiving path.
[0046] The low impedance connecting point of the resonant circuit generated by impedance transformation which is connected to the RF resonant circuit and which also represents one end of the RF line, has two important features:
[0047] 1. As viewed from the low impedance connecting point towards the RF resonant circuit, approximately the impedance of the RF line appears such that the RF line is terminated quasi without reflection at the low impedance connecting end.
[0048] 2. The low impedance connecting point serves as a connecting point for the damping impedance or its transform.
[0049] Since, in the inventive damping concept, the low impedance connecting point is continually used to damp the RF resonant circuit, this damping concept is suited, in particular, when the damping impedances are to be positioned at a spatial separation from the RF resonant circuit using the RF line, and are to be switched on or off, thereby preventing any disturbance of the sensitive surroundings of the RF resonant circuit.
[0050] Optimum noise match of the preamplifier during the receiving process is the main object in order to obtain a maximum SINO. Moreover, the transform of the input impedance of the preamplifier at the low impedance connecting point should be as close as possible to the optimum damping resistance to yield maximum damping of the RF resonant circuit without SINO loss. A decay signal during the receiving process produces broad artificial spectral lines. The signal decays with the time constant TEV during the receiving process which should be as short as possible so that the residual signal is minimum. The phase of the transform of the preamplifier input impedance that appears at the low impedance connecting point, which is required to achieve maximum damping, can be realized through selection of the length of the RF line. During the damping process, maximum damping of the RF resonant circuit can be realized by means of the damping impedance of the damping process. Towards this end, the damping impedance of the damping process transformed at the low impedance connecting point must be approximately equal to the optimum damping resistance (R D) OPT . Of all possible resistance values, (R D ) OPT is that value which produces optimum high damping of the RF resonant circuit and can be calculated for the respective configuration. The optimum damping resistance thereby depends, to first order, on the frequency (o and the matching impedance M K and X C , respectively.
[0051] Maximum damping of the RF resonant circuit during the transmitting process can also be realized using the damping impedance of the transmitting process. If compatible with power requirements, the transform of the damping impedance at the low impedance connecting point should thereby lie at the optimum impedance. In this case, the damping states are the same during the damping and transmitting processes and one single damping impedance is sufficient, i.e. the damping impedance of the transmitting process. This must be switched such that it is also effective during the damping process. If this is not possible, the maximum damping that is compatible with the power requirements can be obtained by weaker transformation in the damping network (i.e. wherein the impedance of the connection that is guided to the RF coil of the respective damping network is closer to R W ).
[0052] While the above-described prior art only contains automatic damping due to power matching in view of the transmitting process and in view of damping at the low impedance connecting point of the RF resonant circuit, the present invention provides additional passive damping impedances in order to present an appropriate damping impedance for each process (transmitting process, damping process, receiving process), thereby improving damping. This is possible without impairing the performance of the system, since today's power transmitters for NMR have sufficient power to optimally supply the RF resonant circuit and also cover the power loss of this additional passive damping impedance.
[0053] The inventive MR detecting configuration considerably reduces the time constant.
[0054] The RF resonant circuit preferably excites the spin system during the transmitting process and detects FID signals during a receiving process, wherein the switching means connects the RF resonant circuit to the RF receiver during the receiving process and to the RF transmitter during the transmitting process. The RF resonant circuit is connected to the RF receiver via the receiver path, the RF resonant circuit is connected to the RF transmitter via the transmitter path.
[0055] In an embodiment of this type, the switching means advantageously comprises a three-phase RF switch, i.e. a switch with three switching positions.
[0056] The RF resonant circuit may alternatively serve only to detect FID signals during the receiving process, and can be damped with the passive damping impedance during the damping process, wherein an RF transmitting circuit is provided for exciting the spin system during the transmitting process, which is preferably disposed spatially orthogonal relative to the RF resonant circuit, wherein at least one further passive damping impedance is connected to the RF transmitting resonant circuit during the transmitting and/or damping process, such that the RF transmitting resonant circuit can be damped with the further passive damping impedance.
[0057] In an advantageous embodiment of the inventive MR detection configuration, at least one of the passive damping impedances is selected such that an optimum impedance (R D ) OPT is present at the low impedance connecting point A, as viewed in the direction of the RF line, wherein in an inductive transformation circuit, in which the reactive portion of the coupling inductance is capacitively compensated by a capacitor, (R D ) opt =ω*M K applies with good approximation, wherein M K corresponds to the mutual inductance of the inductive coupling of the transformation circuit.
[0058] The optimum impedance causes maximum damping and thereby the most rapid decay of the RF resonant circuit. Maximum damping means that the envelope of the current in the resonant circuit damps out within minimum time. The energy present in the RF resonant circuit is thereby dissipated, i.e. transferred into heat, in order to prevent oscillation of the energy between the RF resonant circuit and a different resonant structure. The deviation of the values of the impedances from the optimum impedance may be up to ±30% without substantially extending the decay process (approximately 10% larger time constant).
[0059] In an alternative embodiment, at least one of the damping impedances is selected such that there is an optimum impedance (R D ) OPT at the low-impedance connecting point as viewed towards the RF line, wherein the reactive transformation circuit comprises a capacitive reactance X S which acts as an impedance transformer, wherein the optimum impedance (R D ) OPT is determined by the value of the reactance X S and wherein (R D ) OPT =X S applies to good approximation.
[0060] The reactance is thereby disposed between the high impedance point and the low impedance connecting point of the RF resonant circuit as an impedance transformer.
[0061] A particularly advantageous embodiment of the invention comprises a damping network for generating the connectable passive damping impedance, wherein the damping network comprises a connection to the RF transmitter and is thereby not matched to the RF line, rather to the RF transmitter. The RF resonant circuit is additionally damped during the transmitting process in order to increase its frequency bandwidth to the required value. This reduces the rise time of the current in the inductance of the RF resonant circuit during the transmitting process.
[0062] A further advantageous embodiment comprises a controllable RF resistance, in particular, a PIN diode for generating the passive damping impedance. The damping of the RF resonant circuit during the damping process can be defined by means of the RF resistance, such that the optimum impedance is advantageously generated at the low impedance connecting point.
[0063] The invention also concerns a method for damping an RF resonant circuit of an above-described MR detection configuration, wherein during the damping and/or transmitting process, the RF resonant circuit is damped with a time constant reduction larger than a factor of 2 compared to termination with the characteristic impedance of the RF line at the low impedance connecting point by connecting the passive damping impedance to the resonant circuit using the switching means.
[0064] The spin system is advantageously excited during the transmission process and the FID signal is detected during the receiving process using the same RF resonant circuit.
[0065] Alternatively, the FID signal is detected during the receiving process using the RF resonant circuit and the spin system is excited during the transmitting process using the RF transmitting resonant circuit.
[0066] In an advantageous variant of the inventive method, a passive damping impedance, which is connected via the RF transmitting line, is generated during the transmitting and/or damping process using the damping network which is connected to the RF transmitter, and is not matched to the line, rather to the transmitter.
[0067] The optimum impedance is moreover advantageously generated using the controllable RF resistance and the subsequent transformation at the low impedance connecting point.
[0068] The inventive MR detecting configuration and the associated method realize optimum damping of the RF resonant circuit both during the transmitting, damping and receiving processes, wherein optimum damping in this connection means the damping, at which the transformed damping impedance, relative to the low impedance connecting point, assumes that value which maximally damps the RF resonant circuit.
[0069] Further advantages of the invention can be extracted from the description and the drawing. The features mentioned above and below may be used individually or collectively in arbitrary combination. The embodiments shown and described are not to be understood as exhaustive enumeration but have exemplary character for describing the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0070] FIG. 1 shows a basic circuit diagram of one embodiment of the inventive MR detection configuration with damping devices for the RF resonant circuit which are activated or deactivated during the transmitting and damping process;
[0071] FIG. 2 shows a basic circuit diagram of an alternative embodiment of the inventive MR detection configuration comprising a separate RF transmitting circuit for exciting the spin system;
[0072] FIG. 3 shows a detailed diagram of an embodiment of the inventive MR detection configuration with capacitive coupling of the RF resonant circuit and optimum damping of the RF resonant circuit during the damping process by means of the RF resistance of a diode;
[0073] FIG. 4 shows a detailed diagram of a further embodiment of the inventive MR detection configuration with an inductive impedance transformer for coupling to the RF resonant circuit and with optimum damping of the RF resonant circuit during the damping process using the RF resistance of a diode;
[0074] FIG. 5 shows a detailed circuit diagram of a further embodiment of the inventive MR detection configuration, with which the RF resonant circuit can be optimally damped during the transmitting process by a resistance group and during the damping process by the RF resistance of a diode;
[0075] FIG. 6 shows a detailed diagram of a further embodiment of the inventive MR detection configuration, in which the RF resonant circuit can be optimally damped during the transmitting process by a resistance transformer network and during the damping process by the RF resistance of the diode;
[0076] FIG. 7 a shows the time behavior of a transmitting pulse of the circuit of FIG. 3 or FIG. 4 which is fed into the RF resonant circuit;
[0077] FIG. 7 b shows the time behavior of the current in the inductance of the RF resonant circuit of the circuit of FIG. 3 or FIG. 4 ;
[0078] FIG. 7 c shows the time behavior of the FID signal (nuclear resonance signal) of the circuit of FIG. 3 or FIG. 4 ;
[0079] FIG. 7 d shows the time behavior of the current and the voltage for controlling the transmitting diodes of the circuit of FIG. 3 or FIG. 4 ;
[0080] FIG. 7 e shows the time behavior of the current for controlling the diode D 3 of the circuit of FIG. 3 or FIG. 4 ;
[0081] FIG. 8 a shows the time behavior of the transmitting pulse which is fed into the RF resonant circuit of a first embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0082] FIG. 8 b shows the time behavior of the current in the inductance of the RF resonant circuit of a first embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0083] FIG. 8 c shows the time behavior of the FID signal (nuclear resonance signal) of a first embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0084] FIG. 8 d shows the time behavior of the current and the voltage for controlling transmitting diodes of a first embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0085] FIG. 8 e shows the time behavior of the current for controlling the diode D 3 of a first embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0086] FIG. 9 a shows the time behavior of a transmitting pulse which is fed into the RF resonant circuit of a second embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0087] FIG. 9 b shows the time behavior of the current in the inductance of the RF resonant circuit of a second embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0088] FIG. 9 c shows the time behavior of the FID signal (nuclear resonance signal) of a second embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0089] FIG. 9 d shows the time behavior of the current and the voltage for controlling transmitting diodes of a second embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0090] FIG. 9 e shows the time behavior of the current for controlling the diode D 3 of a second embodiment of the circuit of FIG. 5 or FIG. 6 ;
[0091] FIG. 10 shows a transmitting/receiving device in accordance with prior art, in which the RF resonant circuit is damped at its low-impedance connecting point during the receiving process;
[0092] FIG. 11 a shows a transmitting/receiving device in accordance with prior art, in which the RF resonant circuit is damped during the damping process using a Q switch, and
[0093] FIG. 11 b shows one realization of a Q switch of FIG. 3 using a diode.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0094] The inventive device is schematically shown in FIG. 1 . It is divided into three main blocks, i.e. an RF resonant circuit 1 which may be at a very low temperature (e.g. 20 K or less), a preamplifier module 2 whose temperature is e.g. at 77 K and a transmitter/receiver module 3 with an RF transmitter 8 and an RF receiver 7 , which is usually housed in a spectrometer console. The preamplifier module 2 comprises a receiving path with a low-noise preamplifier 5 comprising a matching network AN and an active preamplifier 5 ′, a transmission path with a damping network 6a for a transmitting process SV with damping resistances R T1 , R T2 and a damping path with a damping network 6 b for a damping process DV with a damping resistance R D and a switching means in the form of an RF switch 4 with which the transmission process SV, damping process DV and receiving process EV can be initiated by producing a connection between the RF receiver circuit 1 and the transmitting path, damping path or receiving path. The damping networks 6 a , 6 b generate damping impedances Z SV , Z DV for damping the RF resonant circuit 1 .
[0095] The radio frequency signals are transmitted among the three main blocks via an RF line 15 with a characteristic impedance R W , an RF output line 12 a , and an RF input line 13 a , which are preferably designed as coaxial cables having low thermal conductivity. A low impedance connecting point A of the RF resonant circuit 1 is thereby connected to the preamplifier module 2 via the RF line 15 .
[0096] The RF resonant circuit 1 of FIG. 1 is designed as a parallel resonant circuit with capacitive coupling, wherein an inductance L with a loss resistance R S is connected in parallel to a resonance capacity C T . Other resonant circuit topologies with capacitive and/or inductive coupling are also feasible ( FIG. 4 ).
[0097] In the embodiment of the inventive MR detection configuration shown in FIG. 1 , the preamplifier module 2 can be switched by means of a switch, i.e. the RF switch 4 , to three different states (transmitting process SV, damping process DV and receiving process EV). Thus, the RF resonant circuit 1 can be damped with the passive damping impedance Z SV during the transmitting process SV and with the passive damping impedance Z DV during the damping process DV. During the transmitting process SV, the RF amplifier (power amplifier) 8 is connected through to the RF resonant circuit 1 . In the short time between transmission and reception, the RF resonant circuit 1 is connected to the damping resistance R D (damping process DV), such that the current in the RF resonant circuit 1 quickly decays. As will be shown below, the dimensioning of this damping resistance R D is extremely critical but can be optimized. The RF resonant circuit 1 is subsequently connected to the low-noise preamplifier 5 (LNA) (receiving process EV). The complex input impedance Z A of the LNAs 5 together with the length of the RF line 15 is selected such that the energy still present in the RF resonant circuit 1 due to the transmitting pulse is optimally discharged. The circuit is primarily dimensioned for an optimum, i.e. high SINO (noise match).
[0098] In the inventive MR detection configuration, the RF resonant circuit 1 and the preamplifier module 2 are spaced apart and are connected to each other via the RF line 15 . The RF switch 4 of the embodiment of FIG. 1 has three phases, i.e. the switch comprises three positions or switching possibilities. The switch and the impedance-controlled and noise-matched LNA 5 permit rapid decay of the RF resonant circuit 1 after application of a transmitting pulse.
[0099] The inventive device permits use of cryogenically cooled RF resonant circuits 1 with maximum quality factor (e.g. of high temperature superconductors=HTSC) in today's high field systems without having to accept the above-described problems caused by the decay process.
[0100] FIG. 2 shows an alternative embodiment, wherein, in addition to the RF resonant circuit 1 , a further RF transmitting resonant circuit 1 a is provided which may have substantially the same structure. The RF resonant circuit 1 of this embodiment only detects FID signals during the receiving process EV and during the damping process DV and is damped with passive damping impedance Z DV , wherein switching over from the damping network 6 b for the damping process DV to the preamplifier 5 for the receiving process EV is effected by a switch 4 ″. The RF transmitting resonant circuit 1 a is provided to excite the spin system during the transmission process SV, which is preferably disposed orthogonally to the RF resonant circuit 1 and can be damped by further passive damping impedances Z SV ′, Z DV ′. A switch 4 ′ is also provided in this case for switching over between the damping network 6 a for the transmitting process SV and a damping network 6 c with a damping resistance R D ′ during the damping process DV. Each RF resonant circuit 1 , 1 a is connected to the preamplifier module 2 via an RF line 15 , 15 a . During the damping process DV, the two switches 4 ″, 4 ′ connect the RF lines 15 , 15 a to the RF resonant circuit 1 or the RF transmitting resonant circuit 1 a to the respective damping resistance R D , R D′ of the damping networks 6 b , 6 c .
[0101] One feasible implementation variant is explained in detail below with reference to FIG. 3 . The RF resonant circuit 1 is modelled as a parallel resonant circuit with capacitance C T and the inductance L and with the loss resistance R S . The RF resonant circuit 1 is adjusted to 50 ohms via the coupling capacitor (matching capacitance) C M . The temperature of the RF resonant circuit 1 may be much lower than the temperature of the following preamplifier module 2 . The RF resonant circuit 1 and the preamplifier module 2 are therefore spatially and thermally separated by the RF line 15 .
[0102] Two transmitting diodes D 1 , D 2 in the preamplifier module 2 , which belong to the switching means, transmit an input signal 13 b from the RF transmitter 8 (not shown in FIG. 3 ) into the RF resonant circuit 2 during the transmitting process SV. A current I BIAS of sufficient strength flows through the two transmitting diodes D 1 , D 2 during the transmitting process SV due to a control circuit 10 a . During the transmitting process SV, a further diode D 3 is also operated by the signal from a further control circuit 9 with a DC current applied in the forward direction, such that the low impedance of the diode D 3 is transformed to a reference point B at the end of the RF line 15 facing away from the RF resonant circuit 1 to a high impedance via a λ/4 line 16 . This high impedance is parallel to the 50 ohm system which comprises the transmitting diodes D 1 and D 2 and the cable 15 and the RF resonant circuit, and can thereby be neglected, i.e. the high impedance then has no influence on the 50 ohm system. When the diode D 3 is not ideal, a further diode D 4 is provided as additional protection of the LNAs 5 against transmitting power.
[0103] The transmitting pulse is followed by switching over to the so-called damping process DV as quickly as possible by means of the control circuits 9 , 10 . During the damping process DV, the energy of the RF resonant circuit 1 is withdrawn as quickly as possible, i.e. the current of the inductance L is reduced as quickly as possible. This is equivalent to maximizing the real part of the impedance which loads the inductance L at a high impedance point M. The imaginary part of this impedance plays a negligible role. It merely determines the frequency of the decay signal but not its time constant. It can be shown that, for high Qs of inductance L, the following equation applies with approximation: (R D ) OPT =1/(ω·C M ). In other words, there is an optimum resistance (R D ) OPT which the RF resonant circuit 1 should see in the direction of the preamplifier module 2 at the low impedance connecting point A in order to minimize the decay time. This optimum resistance (R D ) OPT amounts to some kω, depending on the Q of the inductance L. The diode D 3 is then loaded with the signal of the control circuit 9 , such that its high-frequency series resistance R HF , together with the transform of the input impedance Z A of the amplifier 5 , is transformed via a λ/4 line 16 and the RF line 15 in the vicinity of or, even better, exactly at (R D ) OPT . At the same time, the two transmitting diodes D 1 and D 2 must be blocked by a sufficiently large negative reverse voltage (high voltage=HV) and thus be connected with a sufficiently high ohmic value to prevent them from being automatically transferred into the conducting and low ohmic states due to strong decay signals, and thereby disturbing (R D ) OPT .
[0104] With this device, the RF resonant circuit 1 has an impedance for some microseconds after applying the transmitting pulse (switch position DV in the control circuit 9 and 10 a ), at which the energy in the RF resonant circuit 1 is discharged as quickly as possible, i.e. no strong decay signals remain, which could overload the preamplifier module 2 , the LNA 5 contained therein and/or the following RF receiver 7 (not shown in FIG. 3 ). The base line artefacts caused by the decay signal are also considerably smaller.
[0105] The remaining energy within the RF resonant circuit 1 can be quickly discharged even during the receiving process EV when the two diodes D 3 , D 4 block, by making sure that the input impedance Z A of the LNAs 5 is preferably transformed to the vicinity of (R D ) OPT up to the low-impedance connecting point A of the RF resonant circuit. This can be realized, since low noise GaAs LNAs have very high ohmic values even with input noise matching. For dimensioning the LNA 5 , in particular, for noise matching the adjustment network AN, the priority is clearly to obtain a high SINO and adjust the noise of the preamplifier 5 . Noise-matching of the preamplifier 5 leaves one degree of freedom, i.e. the phase of the reflection factor at the input of the preamplifier 5 which can be controlled by an input side cable length change of the RF line 15 within the preamplifier 5 . This yields the correct input impedance Z A of the matching network AN and thus the maximum damping resistance at the low-impedance connecting point A during the receiving process EV without impairing noise matching.
[0106] It may also be shown that maximum damping of the decay signal during the receiving process EV is equivalent to minimum radiation damping. For minimum radiation damping during the receiving process EV, the coil current in the inductance L, which is produced by the induced voltage, should be minimum. This is the case when the absolute magnitude |Z+j*ω*L+R S | is at a maximum (Z is the impedance from point M as viewed in the direction of the RF line 15 ). This means that radiation damping during the receiving process EV is also minimized using the same configuration that minimizes the decay time during the receiving process EV. Minimum radiation damping and a minimum decay signal electronically damp the RF resonant circuit 1 without affecting the SINO, since the LNA 5 is still noise-matched. This optimum damping improves the receiving bandwidth as a third effect, which reduces the influence of the NMR signals on the SINO at the band ends.
[0107] FIG. 4 shows an RF resonant circuit 1 ′ with inductive coupling. A configuration of this type can also be optimally adjusted to minimize the decay time. The RF resonant circuit comprises a compensation capacitor C k for compensating the blind portion of inductive coupling L k (or also the primary stray inductance). The compensation capacitor C k is not an absolutely necessary physical component. This compensation can also be obtained by shortening the RF line 15 . It can be shown that the optimum resistance of this configuration is (R D ) OPT =ω·M. This configuration is more difficult to realize than the configuration with the capacitive coupling of FIG. 3 . The compensation of the primary stray inductance is required to obtain a minimum decay time, since otherwise the current in the inductive coupling L k remains unnecessarily limited.
[0108] It can also be shown that when the damping resistance R D differs from the optimum impedance (R D ) OPT , beat frequencies may occur in the decay signal. This can be simply explained in that the equivalent circuit of the RF resonant circuit 1 ′ represents a network of fourth order which has two resonances in this topology with unfavorable damping by optimum impedance (R D ) OPT .
[0109] FIG. 5 shows a detailed circuit diagram of a further embodiment of the inventive MR detecting configuration, wherein the RF resonant circuit can optionally be damped by a resistor group R′ T1 , R′ T2 , R′ w (R′ w =characteristic impedance of the RF input line 13 a and output impedance of the RF transmitter 8 , typically also 50 ohms) and by the RF resistance of the diode D 3 . In this configuration, the rise time ι rise of the current in inductance L is reduced during the transmitting process SV. This is achieved in that the RF resonant circuit 1 is additionally damped during the transmitting process SV in order to increase its frequency bandwidth to the required value. Also in this case, the RF resonant circuit 1 need not be interfered with and the required damping network 14 a with damping resistances R T1 , R T2 can be spatially and thermally separated from the RF resonant circuit 1 . The receiving process EV offers the same possibilities as the transmitting process SV. Departing from power matching during the transmitting process SV, the rise time of the coil current can be dramatically reduced, as during the receiving process EV, by the reduction factor Q. The optimum is also the same in this case. The damping resistances R′ T1 , R′ T2 transform the impedance R′ w of the RF transmitter 8 , such that the RF resonant circuit 1 has the optimum impedance (R D ) OPT . This configuration is of course not very efficient, since the major part of the transmitting power is “wasted” in the damping resistances R′T 1 and R′ T2 . The required transmitting power increases quadratically with the Q reduction factor. In another configuration which uses a transformer ( FIG. 6 ) instead of the damping resistance R′ T2 in a damping network 14 b , the required transmitting power increases linearly with the Q reduction factor. It still requires a damping resistance R′ T3 to adjust the RF transmitter 8 to R′ w (50 ohms). If the rise time is reduced by a factor 10 , the required power will be ten times larger in order to obtain the same coil current. This can be easily tolerated with an RF resonant circuit 1 with a high Q value, since it is based on lower powers corresponding to the high Q value.
[0110] One particular advantage thereof is also the fact that the RF transmitter 8 remains adjusted to the preamplifier module 2 when the network is correctly dimensioned, despite impedance transformation. Thus, no undesired transmission cut-offs or failures occur during the transmitting process SV.
[0111] The transmitter adjustment is maintained and for this reason, the normal methods for tuning the probe head via the RF input line 13 a can be used. (tuning/matching, wobbling remain unchanged for the user, the system behaves as if it had a low Q value, as viewed from the outside). If required for the tuning process, the transformation circuit, which is preferably loss-free, can also be bridged through slight expansion of the system, which renders tuning more exact.
[0112] FIGS. 7 a through 7 e are the time dependencies of different signals during the transmitting, damping and receiving processes in the circuit of FIG. 3 or FIG. 4 . The RF resonant circuit 1 , 1 ′ is optimally damped during the damping process DV using the diode D 3 , which yields a short decay time ι fall . There is no additional damping during the transmitting process SV (e.g. with the resistances R′ T1 and R′ T2 of FIG. 5 ), such that the rise time ι rise of the transmitting pulse is relatively large. The further decay time during the receiving process EV is designated with ι EV .
[0113] FIG. 7 a shows the idealized transmitting pulse as transmitted from the RF transmitter 8 .
[0114] FIG. 7 b shows the current of inductance L. This current rises exponentially with the time constant ι rise . ι rise depends on the quality factor of the RF resonant circuit 1 , 1 ′ and produces the following value: ι rise =Q L /ω with power matching on the transmitting side, wherein Q L corresponds to the coil Q value and ω is the angular frequency. After the transmitting process SV and during the damping process DV, the RF resonant circuit 1 , 1 ′ has an impedance other than 50 ohms. The time constant of the decaying signal is also different. If the RF resonant circuit 1 , 1 ′ were loaded with a short or open circuit, the decay time would be ι fall =2*ι rise . If the RF resonant circuit 1 , 1 ′ is loaded exactly with 50 ohms, ι fall =ι rise . It can be demonstrated that there is an optimum impedance (R D ) OPT , at which ι fall reaches a minimum. One can also talk of a Q reduction factor which states the relationship between the coil Q value Q L and the Q value of the RF resonant circuit 1 , 1 ′ with optimum impedance during the damping process DV. This Q reduction factor is calculated as follows (approximation for large Q L ):
Q L Q reso = Q L 2 · ( Q L · R 50 ω · L - 1 ) ) + 1
[0115] Q L : coil Q value
[0116] Q reso : Q value of the RF resonant circuit during the damping process
[0117] R 50 : system impedance, usually 50 ohms
[0118] L: coil inductance
[0119] The time constant ι fall is optimally smaller than the time constant ι rise by half the Q reduction factor.
[0120] FIG. 7 c shows the NMR or FID signal. FIGS. 7 d and 7 e show the control signals for the three processes SV, DV, EV. A current flows through the transmitting diodes D 1 and D 2 during the transmitting process SV. The transmitting diodes D 1 and D 2 are blocked with high voltage (=HV) during the damping process DV, and a current flows through the diode D 3 such that the RF resonant circuit 1 , 1 ′ is loaded with the optimum impedance (R D ) OPT . The current in the diode D 3 may be different during the transmitting and damping processes SV, DV. This is advantageous in that the optimum RF resistance of the diode D 3 can be adjusted during the damping process DV. During the transmitting process SV, however, a current of maximum strength usually flows through the diode D 3 such that it preferably reaches a low ohmic value and protects the preamplifier 5 from being overloaded. On the other hand, point B preferably reaches a high impedance value, thereby minimizing the influence on the transmitting process SV. During the receiving process EV, the current I BIAS for the diode D 3 is switched off. It thereby reaches a high impedance value and does not influence the receiving process.
[0121] In accordance with FIGS. 9 a through e, the advantages of an explicit damping circuit can be utilized during the damping process. This is advantageous in that the explicit damping device can i.a. still achieve optimum damping using diode D 3 etc., while the achievable damping may be limited by the transformed transmitter impedance due to the associated loss in power efficiency.
[0122] The actual damping process is thus divided into two phases, which also have two different time constants ι fall , ι fall 2 for the decaying RF resonant circuit 1 , 1 ′. FIGS. 9 a through e show the time dependence of different signals during the transmitting, damping and receiving process in an embodiment of this type of circuit of FIG. 5 or FIG. 6 . The RF resonant circuit 1 is additionally damped during the transmitting process SV and during the first part DV 1 of the damping process using the damping resistances R′ T1 , R′ T2 and R′ T3 respectively, and optimally damped during the second part DV 2 of the damping process using the diode D 3 . This reduces the rise time ι rise and the fall time ι fall of the transmitting pulse. The residual signal decays with ι EV during the receiving process EV.
[0123] In particular, when the requirements are low, the presence or use of the explicit damping device using the diode D 3 etc. can alternatively be omitted. FIGS. 8 a - e show the time dependence of different signals during the transmitting, damping and receiving processes of this embodiment or mode of operation of the circuit of FIG. 5 or FIG. 6 . The RF resonant circuit 1 is damped both during the transmitting process SV and during the damping process DV using the damping resistances R′ T1 , R′ T2 and R′ T3 , respectively. This reduces the rise time ι rise and fall time ι fall of the transmitting pulse. The residual signal decays with ι EV during the receiving process. Thus, only the RF transmitting pulse is switched off during the damping process DV, which already results in automatically damped decay of the current of the RF resonant circuit 1 , 1 ′ ( FIG. 8 b ). This is advantageous for those cases, in which damping using this mode of operation is sufficiently large, in that on the one hand, the complexity of the system and operation is reduced. Secondly, since the rise and decay times are identical, there will be no additional problems for calibrating the different pulse lengths (in practice, in particular 90 vs. 180 vs. 360 degrees), since the delays at the start and end of the pulse are identical and thus the length of the output pulse (as a current in the RF resonant circuit 1 , 1 ′) still corresponds linearly to the length of the transmitting pulse.
[0124] In general, it must be noted that with high damping factors and long RF lines 15 , additional effects may occur due to the properties of the RF line 15 . These may additionally influence, in particular, also reduce the maximum achievable damping ratio. This is due to the fact that the mentioned transformation properties of the lines only apply for exactly the working or resonance frequencies. For other frequencies, the transformations are slightly different. These effects increase the larger the cable length compared to the wavelength. As soon as the line lengths and damping are sufficiently large that these errors within the desired bandwidth of the damped system become significant, they must be taken into consideration in the design of the overall system and for optimizing the components, in order to obtain optimum results.
LIST OF REFERENCES
[0125] (1) “A probehead with switchable quality factor. Suppression of radiation damping”; C. Anklin, M. Rindlisbacher, G. Otting and F. H. Laukien; J. Magn. Res. B106, p199-201, 1995
[0126] (2) “Fast recovery, high sensitivity NMR probe and preamplifier for low frequencies”; D. I. Hoult; Rev. Sci. Instr. 50(2), February 1979
[0127] (3) “Interplay among recovery time, signal, and noise: Series- and parallel-tuned circuits are not always the same”; J. B. Miller, B. H. Suits, A. N. Garroway, M. A. Hepp; Concepts in Magn. Res. Vol 12, issue 3, p125-136
[0128] [4] “NMR Signal Reception: Virtual Photons and Coherent Spontaneous Emission”; D. I. Hoult, B. Bhakar; Concepts in Magn. Res. Vol 9, issue 5, p227-297
LIST OF REFERENCE NUMERALS
[0129] SV transmitting process
[0130] SV damping process
[0131] DV 1 first partial process of the damping process
[0132] DV 2 second partial process of the damping process
[0133] EV receiving process
[0134] AN matching network at the input of the preamplifier
[0135] A low-impedance connecting point of the RF resonant circuit
[0136] B reference point at the end of the RF line facing away from the RF resonant circuit
[0137] M high-impedance point of the inductance of the RF resonant circuit
[0138] V reference point in the preamplifier between the matching network and the active part of the preamplifier
[0139] R S loss resistance of the resonance inductance
[0140] R A transform of the loss resistances of the RF resonant circuit related to the low-impedance connecting point of the RF resonant circuit
[0141] R Q damping resistance of the “Q switch”
[0142] R W characteristic impedance of the RF line 15
[0143] R′ W characteristic impedance of the RF input line 13 a and the output impedance of the RF transmitter
[0144] R HF RF resistance of the diode D 3 (this RF resistance depends on the DC current I BIAS that flows through the diode D 3 )
[0145] R D damping resistance during the damping process (belongs to the damping impedance Z DV )
[0146] (R D ) OPT optimum damping resistance at the low-impedance connecting point of the RF resonant circuit, as viewed in the direction of the RF line
[0147] R T1 , R T2 damping resistances during the transmitting process which belong to the damping network 6a (are components of the damping impedance Z SV )
[0148] R′ T1 , R′ T2 damping resistances during the transmitting process that belong to the damping network 14 a
[0149] R′ T3 damping resistance during the transmitting process that belongs to the damping network 14 b with impedance transformer
[0150] L inductance of the RF resonant circuit
[0151] L K inductive coupling
[0152] C T resonance capacitance of the RF resonant circuit
[0153] C M coupling capacitor of the RF resonant circuit
[0154] M K mutual inductance of the inductive coupling
[0155] C K compensation capacitor of inductive coupling
[0156] X S reactance of the coupling capacitor CM(X S =1/(oCM))
[0157] Z SV damping impedance during the transmitting process
[0158] Z DV damping impedance during the damping process
[0159] Z SV ′ damping impedance during the transmitting process
[0160] Z DV ′ damping impedance during the damping process
[0161] Z A input impedance of the matching network AN including preamplifier
[0162] D 1 transmitting diode
[0163] D 2 transmitting diode
[0164] D 3 diode (component of the switching means)
[0165] D 4 diode
[0166] ι rise rise time (time constant) of the coil current during the transmitting process
[0167] ι fall fall time (time constant) of the coil current during the damping process
[0168] ι fall1 , ι fall2 fall time (time constant) of the coil current with two consecutive partial processes of the damping process
[0169] ι EV fall time (time constant) of the coil current during the receiving process
[0170] I BIAS current within the control circuit
[0171] I 11 BIAS current through the PIN diode
[0172] 1 RF resonant circuit with capacitive coupling
[0173] 1 ′ RF resonant circuit with inductive coupling
[0174] 100, 100′ RF resonant circuit
[0175] 1 a RF transmitting resonant circuit
[0176] 2 preamplifier module
[0177] 3 transmitter/receiver module
[0178] 4 , 4 ′, 4 ″ RF switch in the preamplifier module
[0179] 5 preamplifier (LNA) including matching network AN
[0180] 5 ′ active part of the preamplifier
[0181] 6 a , 6 c damping network for the transmitting process
[0182] 6 b damping network for the damping process
[0183] 7 RF receiver
[0184] 8 RF transmitter
[0185] 9 control circuit for the diode D 3 . The preamplifier 5 can be connected or disconnected by the diode D 3 . Moreover, damping of the RF resonant circuit during the damping process can be defined with the RF resistance R HF of the diode D 3
[0186] 10 a control circuit for the transmitting diodes D 1 and D 2 that belong to the switching means. These transmitting diodes can connect/disconnect the signal from the RF transmitter to and from the RF resonant circuit. The circuits of FIG. 5 and FIG. 6 achieve at the same time also additional damping of the RF resonant circuit during the transmitting process using the resistances R′ T1 , R′ T2 and R′ T3 , respectively
[0187] 11 RF switch of the “Q switch”
[0188] 12 a RF output line to the RF receiver
[0189] 13 a RF input line from the RF receiver
[0190] 13 b input signal from the RF transmitter
[0191] 14 a damping network for the transmitting process (it contains the damping resistances R′ T1 , and R′ T2 )
[0192] 14 b damping network for the transmitting process (it contains the damping resistance R′ T3 and an inductive impedance transformer)
[0193] 15 RF connecting line between RF resonant circuit and preamplifier module
[0194] 15 a RF connecting line between RF transmitting resonant circuit and preamplifier module
[0195] 16 , 17 λ/4 line | A magnetic resonance (MR) detection configuration comprising at least one RF resonant circuit ( 1 ) with an inductance (L), a preamplifier module ( 2 ) and an RF receiver ( 7 ), wherein a reactive transformation circuit is connected between a high-impedance point (M) of the inductance (L) and a low-impedance connecting point (A) of the RF resonant circuit ( 1 ), which acts as an impedance transformer and wherein the low-impedance connecting point (A) is connected to the preamplifier module ( 2 ) via an RF line ( 15 ) having a characteristic impedance R W ), is characterized in that at least one passive damping impedance (Z DV , Z SV , Z DV′ , Z SV′ ) is provided in the preamplifier module ( 2 ) downstream of the RF line ( 15 ), wherein the passive damping impedance (Z DV , Z SV , Z DV′ , Z SV′ ) can be connected to the resonant circuit ( 1 ) by a switching means during a damping and/or transmitting process, and wherein the respective amount of the complex reflection factor of passive damping impedance (Z DV , Z SV , Z DV′ , Z SV′ ) relative to the characteristic impedance R W ) of the RF line ( 15 ) exceeds a value of 0.5. This presents an MR detection configuration with an extensive damping concept, wherein all three processes (transmitting, damping and receiving processes) are optimized. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a railroad superstructure supporting framework, with reinforced concrete prefabricated elements, and a prefabricated reinforced concrete platform therefor.
Prior railroad superstructure supporting frameworks comprised pre-compressed reinforced concrete sleepers supported on a ballast of crushed stones.
Such a conventional system has a great use flexibility and can exploit the natural adaptability of the crushed stones to unexpected stresses.
On the other hand, this system requires frequent maintenance operations, with a consequent slowing down and interruption of the train traffic, in particular in a case of a mixed type of traffic with a high variability of load per axle, speed and features.
Moreover, such a conventional system provides for the use of broad building and operation tolerances, which are not compatible with the requirement related to the use of high speed trains.
Because of this reasons, in these last years there have been experimented, in several countries, different types of supporting frameworks, for example including sleepers directly applied to a foundation made of reinforced concrete.
Actually, in these alternative systems the maintenance requirements are very reduced; however, possible breakages of the structure and components thereof require very expensive and delicate repairing operations, for re-building in situ the broken concrete foundation and for replacing the degraded bedding materials. Thus, a possible replacing of prefabricated components, if required, is such as to nullify the provided advantages.
In fact, in these supporting frameworks in which the sleepers are directly supported on concrete material, it is not possible to exploit the natural adaptability of the crushed stones to unexpected stresses and, moreover, these systems do not posses the use flexibility characterizing the conventional supporting framework system.
Because of the above mentioned reasons, the attempts to design new systems have not provided an acceptable solution, and the broad range of different approaches attempted through the overall world, sometimes on a large scale, is an evident proof of this.
In this connection it should be pointed out that short duration and small scale experiments in this field do not provide a significative information and this slows down the development time of new technologies.
On the other hand, there subsists a great need of a railroad superstructure supporting framework which has a better geometric configuration, a greater reliability and duration and, moreover, can be easily fitted to existing railroads while reducing the environmental impact especially with respect to the noise and vibrations.
SUMMARY OF THE INVENTION
Accordingly, the main object of the present invention is to provide a new type of railroad superstructure supporting framework which allows to greatly reduce the building, operation and maintenance tolerances.
Another object of the present invention is to provide such a railroad superstructure supporting framework which, in addition to increasing the stability of the rails, under dynamic loads, is also adapted to greatly reduce the vibrations transmitted to the train cars and the encompassing environment.
Another object of the present invention is to provide such a railroad superstructure supporting framework which requires very reduced programmed maintenance operations with respect to the prior art railroad superstructure supporting frameworks.
This aspect is particularly important both for railroad tracks in environments polluted by powders, fumes and noise, as well as in tunnels, and for railroad tracks of a high speed traffic type and with a reduced possibility of alternative tracks, because of the geomorphologic characteristics of the environment.
According to one aspect of the present invention, the above mentioned objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a railroad superstructure supporting framework including reinforced concrete prefabricated elements, characterized in that said supporting framework comprises prefabricated platforms, each comprising a reinforced concrete block having, on a top face thereof, a plurality of evenly spaced parallel recesses provided for receiving each a sleeper for supporting rail elements, through the interposition of a bedding material.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the railroad superstructure supporting framework with reinforced concrete prefabricated elements according to the present invention will become more apparent from the following detailed description of a preferred embodiment thereof which is illustrated, by way of a merely indicative but not limitative example, in the figures of the accompanying drawings where:
FIG. 1 is a top plan view of a prefabricated platform for making the railroad superstructure supporting framework according to the present invention;
FIG. 2 is a cross-sectional view substantially taken along the like II--II of FIG. 1;
FIG. 3 is another cross-sectional view substantially taken along the line III--III of FIG. 1;
FIG. 4 is a cross-sectional view, taken at the reinforced concrete platform, of the subject railroad superstructure supporting framework;
FIG. 5 is a further cross-sectional view of the subject railroad superstructure supporting framework taken at a sleeper thereof; and
FIGS. 6 to 9 are schematic views showing several possibilities for locating a sleeper inside a related housing provided in the prefabricated reinforced concrete platform.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the number references of the above mentioned figures, the railroad superstructure supporting framework according to the present invention comprises a prefabricated reinforced concrete platform, generally indicated at the reference number 1, comprising a substantially parallelepipedal block having, on the top face thereof, a plurality of evenly spaced and parallel recesses 2.
These recesses 2 are so designed as to house, with a set cross and longitudinal clearance, a plurality of sleepers 3, which are of the pre-compressed reinforced concrete prefabricated type.
The depth of the above mentioned recesses is less than the height of the sleepers 3, so as to allow the sleepers to upwardly project from the platform 1.
At the middle longitudinal axis of the platform 1 there is arranged a channel member 4, which transversely crosses the recesses 2 and extends for the overall length of the platform.
On the block of the platform 1 there are moreover provided draining channels 5 which extend from the mentioned channel element 4, in a transversal direction, and exit the sidewalls of the platform.
Advantageously, the platform 1 is provided with adjustable height foot elements, of any known types, which are housed in suitable holes 6 and traverse the platform from the top face to the bottom face thereof.
As shown, said platform 1 is also provided with a plurality of holes 7 extending from the top face to the bottom face thereof, in order to allow bedding material to be conveyed between the platform 1 and the foundation on which the platform is arranged.
The walls and bottom of the recesses 2 are coated by an elastomeric material layer.
Moreover, to the bottom face of the platform 1 there is applied a resilient material layer, for example made of resilient mattress elements, having preferably a thickness from 10 to 25 mm, depending on requirements, and which are glued at a set position.
Near the longitudinal end portions of the channel element 4, there are formed throughgoing holes 8 which are used to fix the platform 1 to the foundation 9, made of reinforced concrete, and to connect to one another the several platforms, by means of a prefabricated type of joint element 10.
The sleepers 3 are engaged in their recesses 2 through the interposition of a bedding material, comprising a polyurethane resilient cap 21, contacting the sleeper and supported by injecting fluid concrete material 22, of high strength, provided for filling, by a falling or pumping effect, the remaining cavity between the sleeper 3 and its related recess 2 the walls of which, as stated, are coated by an elastomeric material layer (see FIGS. 8 and 9).
Accordingly there are provided two tandem arranged bedding steps: the first, consisting of the polyurethane resilient cap 21, having the required duration and reliability features, and the second consisting of the concrete fluid material 22, for example a concrete material commercially known with the mark of RECOMAT, having a high strength, and adapted to quickly fill the hollows of the recesses 2, and also adapted to resist against any outer stresses.
The sleeper 3, made of pre-compressed reinforced concrete, and having a mass much less than that of the platform, allows to absorb without any damages the dynamic stresses, pulses and shocks due to the train car components coupled to the sprung and un-sprung masses of the cars and increased by possible surface unevennesses of the train wheels and rails, by the geometric unevennesses of the latter as well as by the impacts and shocks due to the movements of the cars about their vertical axis, because of the reaction forces transmitted by the rails.
On the sleepers 3 there are arranged the rails 11 which are affixed by means of resilient clamping means 12, of any known type, for example of the type commercially known with the mark PANDROL, through the interposition of a resilient under rail sole 13.
The laying and fine adjusting procedure for the geometry of the rail, in the railroad superstructure supporting framework according to the invention is as follows.
The laying of the railroad superstructure supporting framework according to the present invention, provides the building of a reinforced concrete foundation, which is directly poured, by means, for example, of a precision vibrating-finishing machine.
As the curing of the concrete permits this, one can lay stopper elements which are affixed to the underlaying foundation, for example by means of affixing pins, re-coring, by means of an epoxide mortar.
During this step, it is not necessary to perform any fine adjustements of the platforms since the final adjustement will be performed on the rail spans and related sleepers; on the other hand, some laying tolerances must be respected.
Since no fine adjustement is necessary with respect to the platforms 1, the latter can be quickly installed, without the need of performing frequent adjustments of the foot elements, since the tolerances of the foundation, which is made with a good precision, are of the same magnitude order as those required for the laying of the platforms.
If required, an adjustement of the positions of the platforms 1 can be anyhow performed, by operating on the adjustable foot elements and then the bedding concrete material 23 will be pumped between the platforms 1 and the foundation 9.
This bedding concrete is not affected by the environment moisture and it does not require steam or other means for a quick curing thereof, and is not subjected to any substantiall contraction or cracks, has an optimum resistance against compression and flexure so as to prevent any cracks from being formed susceptible to receive degrading rain water.
After having installed the platforms, the sleepers can be arranged in their recesses and the rail span can be then installed.
Then an adjustement and aligning step will be performed, by suitably displacing the sleepers 3 in their recesses 2, and, after this step, the bedding concrete 22 will be poured into said recesses 2.
The possibility of performing a fine locating of the sleepers 3 in their recesses 2 formed in the platform 1 allows to meet the set tolerances, even if they are very small.
The day after the pouring, or pumping, of the bedding concrete into the recesses 2 for the sleepers, the rail can be used, if necessary, for a normal railroad operation.
From the above disclosure and the figures of the accompanying drawings, it should be apparent that the railroad superstructure supporting framework according to the invention provides a geometric configuration which is very accurate, and has a great reliability and duration, as well as a very reduced environment impact, with respect to the prior art supporting framework systems for the intended use.
While the invention has been disclosed and illustrated with reference to a preferred embodiment thereof, it should be apparent that the disclosed embodiment is susceptible to several modifications and variation all of which will come within the spirit and scope of the appended claims. | A railroad superstructure framework made in the form of a reinforced concrete block is provided on a top face thereof with a plurality of evenly spaced parallel recesses of a certain depth. Each recess receives a sleeper having a height greater than the certain depth. A middle region of the concrete block is provided with a channel element transversely crossing the plurality of recesses. A plurality of draining channels extend transversely from the channel element to an outside environment to allow for water drainage from the channel element of the concrete block. | 4 |
FIELD OF THE INVENTION
Background
[0001] The invention relates to a clutch arrangement for a vehicle and a method for operating a vehicle.
[0002] Such a clutch arrangement is known from DE 199 14 350 B4. That publication describes a method for operating a motor vehicle with an internal combustion engine and at least one electric motor. The electric motor can be engaged with a wheel hub of the vehicle shaft as a function of its rotational speed via an automatically closing, non-positive fit, centrifugal force clutch. A non-positive fit to the centrifugal force clutch exists only when the electric motor is activated and the electric motor is rotating at high rotational speeds, while the centrifugal force clutch is open when the electric motor is deactivated or is rotating at low rotational speeds. The non-positive actuation of the clutch leads to friction losses due to clutch slip.
[0003] DE 198 09 302 A1 shows a centrifugal force clutch for small motors with an adjustment device that is actuated by centrifugal force and rotates with the motor shaft and is arranged on the free end of a follower sleeve mounted on the motor shaft. The adjustment device displaces a driven element mounted on the follower sleeve above a certain rotational speed axially from a position where it can rotate freely on the follower sleeve to a position in which a positive and/or non-positive fit exists between the driven element and follower sleeve. The formation of the adjustment devices on the follower sleeve is structurally complicated and also requires axial installation space on the free end of the follower sleeve.
SUMMARY
[0004] Therefore, one objective of the invention is to provide a clutch arrangement of the type named above that prevents friction losses during operation and is easy to construct. Another objective is to provide a method for operating a vehicle with such a clutch arrangement.
[0005] The objective is achieved by one or more features of the invention.
[0006] A clutch arrangement for the detachable connection of two shafts is provided in which at least one shift sleeve that can move coaxially on one of the shafts can be moved by centrifugal force actuation as a function of the increase in rotational speed of a shaft out of an engaged position locking the shafts in rotation into a position decoupling the shafts. Therefore, above a predetermined rotational speed, the shafts can be decoupled from each other without torque using centrifugal force actuation. In addition, through the shift sleeve, a positive-fit coupling of the shafts is enabled, wherein friction losses can be avoided by a non-positive coupling of the shafts.
[0007] Advantageously, for the centrifugal force actuation of the shift sleeve, one or more centrifugal force weights locked in rotation with one of the shafts are provided for generating a centrifugal force. The centrifugal force weights engage followers for centrifugal force actuation in the shift sleeve. In this way, an easily constructed, installation space-saving, centrifugal-force actuated clutch arrangement is achieved, through which two shafts can be automatically coupled with each other as a function of rotational speed.
[0008] In one especially preferred construction of the invention, the shift sleeve is arranged so that it can move coaxially on an end area of a first shaft and here encloses at least partially a coaxially arranged end area of a second shaft so that it can move relative to this shaft. Advantageously, one or more centrifugal force weights are locked in rotation with the end area of the second shaft. In this way, the clutch arrangement can be switched as a function of the rotational speed of the second shaft, actuated by centrifugal force. For the centrifugal force actuation, one or more centrifugal force weights engage the followers in the end section of the shift sleeve facing the end area of the second shaft.
[0009] In another especially preferred construction, the first shaft is formed by an engine shaft of an electric motor and the second shaft is formed by a transmission shaft of a vehicle transmission. Here, for example, in hybrid vehicles, an electric motor integrated in the conventional drive train can be coupled with a positive fit on its engine shaft via the clutch arrangement according to the invention with the transmission shaft, especially transmission output shaft, and can be automatically decoupled from this as a function of the rotational speed of the transmission shaft by centrifugal force. In this way, slip losses at higher rotational speeds of the transmission shaft or at higher vehicle speeds can be minimized by decoupling the electric motor from the drive train. Because the clutch arrangement according to the invention automatically opens as a function of rotational speed, actuated by centrifugal force, an additional actuator and a corresponding control are omitted.
[0010] In another especially preferred construction of the invention, the shift sleeve is arranged so that it can move on its inner diameter on a first shaft between a position locked in rotation with a positive fit with this shaft and a position where it can rotate freely on this shaft and is locked in rotation with a second shaft on its outer diameter.
[0011] For the rotationally locked connection of the shift sleeve to the second shaft, a coaxially arranged clutch arrangement can be provided. Advantageously, the shift sleeve is locked in rotation via a clutch housing to the second shaft. Preferably, the clutch housing has a hub-shaped end section that at least partially coaxially encloses the shift sleeve and is locked in rotation with this sleeve with a positive fit and can be moved axially. In this way, the shift sleeve is guided axially for a displacement on its outer diameter on the clutch housing. In the position of the shift sleeve coupled with the first shaft, a drive power or a torque can be transferred between the first and second shafts via this sleeve and the clutch housing.
[0012] Here, for example, on the inner lateral surface of the hub-shaped section of the clutch element, there are radial projections that are locked in rotation on the outer diameter of the shift sleeve in corresponding axial, longitudinal recesses and engage so that it can move longitudinally. For example, an interference fit or plug-in tooth engagement can be provided, in particular, with wedge-shaped or spline-shaped teeth.
[0013] For the positive fit coupling with the first shaft, on the inner diameter of the shift sleeve there are advantageously several projections extending radially inward with a tab-like shape in the circumferential direction one after the other. In the position of the shift sleeve coupled with the first shaft, these engage rotationally locked in opposite, corresponding longitudinal recesses on the outer diameter of the first shaft and can move axially. Advantageously, the recesses are limited in the axial direction by an annular groove that surrounds the outer diameter of the first shaft and in which the projections can engage in the position of the shift sleeve where it can rotate freely on the first shaft.
[0014] Preferably, the followers of the centrifugal force weights and the shift sleeve are in areal contact on corresponding inclined surfaces for transmitting an axial adjustment force to the shift sleeve.
[0015] It is an advantage when each follower is constructed as an axial projection on the centrifugal force weight tapering toward its free end for engaging in an end section of the shift sleeve.
[0016] The inclined surfaces can each be formed by a bevel on the followers and shift sleeve.
[0017] Preferably, the inclined surfaces are constructed as conically shaped contact surfaces on the followers and shift sleeve and form a conical connection.
[0018] Advantageously, several centrifugal force weights that can move orthogonally at the end area of the first shaft and are arranged one behind the other in the circumferential direction are integrated in a pot-shaped housing section of the clutch element arranged coaxial to the end area of the second shaft. Thus, in a simple way, the centrifugal force weights can be arranged compactly, in rotationally locked connection with the second shaft, guided with centrifugal force actuation. Preferably, the centrifugal force weights are arranged in a uniform distribution in the circumferential direction.
[0019] A simple fastening of the clutch housing is achieved if this has a flange-like end section that is formed coaxial to the second shaft and encloses the end area of the second shaft at least in some sections and is connected locked in rotation and axially fixed with this shaft. For this purpose, for example, an interference fit can be provided. Positive-fit connections are also conceivable.
[0020] For restoring a centrifugal force actuated displacement of the shift sleeve, a restoring device is provided. This advantageously has restoring spring means arranged coaxial to the first shaft. Preferably, these tension the shift sleeve against the followers of the centrifugal force weights. In this way it is guaranteed that the shift sleeve and followers are in constant areal contact on the inclined surfaces. One or more compressive springs or tensile springs can be provided as the restoring spring means. The restoring spring means can have at least one helical spring surrounding coaxially the first shaft in some sections. These can be supported axially on a spring end on one end of the shift sleeve and on the other spring end on the first shaft, for example, on an axial securing element connected to this shaft or on a shaft projection. Alternatively, one or more installation space-saving plate springs can be provided as restoring spring means. Advantageously, the restoring spring means are supported on the shift sleeve by means of an axial support, in order to optionally compensate for rotational speed differences between this sleeve and the restoring spring means, especially when the shift sleeve is located in the position where it can rotate freely on the first shaft.
[0021] According to another aspect of the invention, a method for operating a vehicle with a clutch arrangement for detachable connection of two shafts is provided. Here, the clutch arrangement is moved from a state rotationally locking the shafts with a positive fit as a function of the increase of the rotational speed of a shaft at a predetermined rotational speed through centrifugal force actuation into a state decoupling the shafts from each other. In this way it is possible to keep the clutch arrangement closed when the vehicle is at a standstill or at lower rotational speeds and to open the clutch arrangement with centrifugal force actuation at higher rotational speeds.
[0022] In this way, for example, the engine shaft of an electric motor can be decoupled with centrifugal force actuation from a transmission shaft of a vehicle transmission as a function of the rotational speed of the transmission shaft at high transmission shaft rotational speeds or at high vehicle speeds. In a state decoupled from the transmission shaft, an auxiliary engine drive can be driven or continued by the electric motor, in particular, at high vehicle speeds, independent of the rotational speed of the transmission shaft or the vehicle speed.
[0023] For closing the clutch arrangement, it is advantageous if the rotational speeds of the shafts are synchronized for preventing friction losses in a positive-fit coupling of the shafts. For example, for the positive-fit coupling of the engine shaft of the electric motor to the transmission shaft, the rotational speeds of the engine shaft and the transmission shaft can be synchronized by the electric motor. The synchronization can be performed by means of the electronic rotational speed control of the electric motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Additional features of the invention are given from the following description and from the drawings, in which an embodiment of the invention is shown in simplified form. Shown are:
[0025] FIG. 1 a perspective diagram of a clutch arrangement according to the invention,
[0026] FIG. 2 a longitudinal section of the clutch arrangement from FIG. 1 in a first operating state,
[0027] FIG. 3 an enlarged section from FIG. 2 ,
[0028] FIG. 4 a cross section of the clutch arrangement along the line A-A in FIG. 3 ,
[0029] FIG. 5 a partial longitudinal section of the clutch arrangement in a second operating state,
[0030] FIG. 6 a partial longitudinal section of the clutch arrangement in a third operating state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] FIGS. 1 to 4 show an example construction of a clutch arrangement according to the invention for a vehicle for the detachable connection of two shafts. A first and a second shaft 1 , 2 are arranged coaxially opposite each other at their end areas. The first shaft 1 is here formed as an example by the engine shaft of a not shown electric motor and the second shaft 2 by a transmission shaft, in particular, a transmission output shaft, of a not shown vehicle transmission.
[0032] The clutch arrangement has a shift sleeve 3 that is arranged so that it can move coaxially on the end area of the first shaft 1 and encloses the end area of the second shaft 2 so that it can move coaxially to this shaft on a section. Here, the shift sleeve 3 is constructed so that it can be locked in rotation with a positive fit on its inner diameter with the first shaft land connected to the second shaft 2 so that it can move locked in rotation with a positive fit via a clutch housing simultaneously on its outer diameter. The clutch housing encloses the end areas of the shafts 1 , 2 coaxially. On its axial side facing the second shaft 2 , the clutch housing forms an end section 4 constructed for connecting as a ring flange and on which the clutch housing is pressed on the end area of the second shaft 2 in an interference fit rotationally locked and axially fixed ( FIGS. 1 and 2 ). Positive fit or positive-fit/non-positive-fit or material-fit connections between the clutch housing and second shaft 2 are also conceivable.
[0033] On its axial side facing the first shaft 1 , the clutch housing forms a hub-shaped end section 5 that coaxially surrounds the shift sleeve 3 on its outer diameter. Here, the shift sleeve 3 is locked in rotation on the hub-shaped end section 5 with the clutch housing with a positive fit and can be moved axially. For this purpose, radial projections 6 that engage locked in rotation and movable in the longitudinal direction on the outer diameter of the shift sleeve 3 in corresponding, axially extending, longitudinal recesses 7 or longitudinal grooves are formed on the inner lateral surface of the hub-shaped end section 5 ( FIG. 4 ). The projections 6 and the recesses 7 each have a continuous axial construction, i.e., over the entire axial length of the hub-shaped end section 5 or shift sleeve 3 . In this way, on the shift sleeve 3 , over the entire axial length on its outer diameter, an axial guidance and a positive fit in the circumferential direction on the clutch housing can be achieved for transmitting a drive power. The recesses 7 and projections 6 are each arranged distributed uniformly over the circumference. They each have a rectangular cross sectional profile and form involute teeth between the clutch housing and shift sleeve 3 .
[0034] The illustrated first operating state shows the clutch arrangement in closed output state, i.e., coupling the shafts 1 , 2 . Here, a torque or a drive power can be transmitted between the first and second shafts 1 , 2 via the shift sleeve 3 and the clutch housing. In the output state, the shift sleeve 3 is located on its inner diameter in a position locked in rotation with a positive fit with the first shaft 1 . Here, the shift sleeve 3 forms on its end facing the end area of the first shaft 1 on the inner diameter several radially inward, tab-shaped, extending projections 8 one behind the other in the circumferential direction. These engage in opposing, corresponding longitudinal recesses 9 or longitudinal grooves rotationally locked and axially movable on the outer diameter of the end area of the first shaft 1 ( FIG. 3 ). The recesses 9 extend starting from the end of the first shaft 1 in the axial direction. For an axial displacement from the starting position, the shift sleeve 3 is guided on its inner diameter on the projections 8 into the recesses 9 on the first shaft 1 .
[0035] On its end facing the end area of the second shaft 2 , the shift sleeve 3 is in active connection with several centrifugal force weights 10 that are rotationally locked and can move orthogonal to the end area of the second shaft. These weights are used for the centrifugal force actuation of the shift sleeve 3 as a function of the centrifugal force generated by the rotation of the second shaft 2 on the centrifugal force weights 10 . The centrifugal force weights 10 are distributed uniformly over the circumference of the first shaft 1 and are integrated rotationally locked in a pot-shaped section 11 of the clutch housing and are arranged radially movable. The centrifugal force weights 10 are here guided on the axial inner walls of the clutch housing and by a not shown holding device in the circumferential direction. In the shown first operating state, the second shaft 2 does not rotate or has only a low rotational speed. Here, the centrifugal force weights 10 are each radially inside on the outer diameter of the second shaft 2 . For this purpose, the radially inner end sides of the centrifugal force weights 10 are adapted to the outer diameter of the second shaft 2 with a shape curved concavely inward. The centrifugal force weights 10 are each block-shaped with narrow sides in the axial and radial directions and wide sides in the circumferential direction. The centrifugal force weights 10 have, on their narrow axial sides facing the first shaft 1 , radially inner followers 12 for centrifugal force actuation of the shift sleeve 3 . The followers 12 are each formed integrally with the centrifugal force weight 10 as an axial shoulder or projection. Here, the shift sleeve 3 is arranged on its end section coaxially surrounding the end area of the second shaft 2 radially spaced apart from the outer diameter of the second shaft 2 and thus forms a radial air gap to this shaft. In this gap, the followers 12 on the shoulders or projections engage. For this purpose, the followers 12 are arranged coaxial to the shift sleeve. The projections forming the followers 12 are tapered on their radially outer side toward their ends facing the first shaft 1 . Here, they are in areal contact with the inner diameter of the shift sleeve 3 on corresponding inclined surfaces 14 , 15 at an angle to the rotational axis 13 . These are oriented such that, from the centrifugal force of the centrifugal force weights 10 transmitted to the followers 12 on the inclined surfaces 14 , 15 , an adjustment force acting in the axial direction facing away from the second shaft 2 is transmitted onto the shift sleeve 3 . The shift sleeve 3 and followers 12 here form, on the inclined surfaces 14 , 15 , a cone connection with an inner cone on the inner diameter of the shift sleeve 3 and corresponding outwardly conical contact surfaces on the followers 12 .
[0036] For restoring the shift sleeve 3 , axial restoring spring means 16 are provided ( FIGS. 1 to 3 ). During a centrifugal force actuated axial displacement of the shift sleeve 3 from the starting position, these spring means generate a restoring spring force acting against the displacement. Here, for example, a helical spring arranged coaxial to the first shaft 1 is provided as a compression spring for restoring the shift sleeve 3 . This is supported with one spring end by means of an axial bearing 17 on the end of the shift sleeve 3 facing the end area of the first sleeve 1 and with the other spring end on an axial securing element 18 , here a securing ring pressed onto the first shaft 1 . The restoring spring 16 tensions the shift sleeve 3 against the followers 12 of the centrifugal force weights 10 in the axial direction. Therefore, a constant areal contact of the followers 12 and shift sleeve 3 is guaranteed on the inclined surfaces 14 , 15 both for a centrifugal force actuated displacement for opening the clutch arrangement and also for a restoring of the shift sleeve 3 for closing the clutch arrangement through the restoring spring force generated by the restoring spring means 16 .
[0037] For the rotation of the second shaft 2 , the co-rotating centrifugal force weights 10 are pressed radially outward by the centrifugal force, so that a radial air gap is produced between the radially inner end sides of the centrifugal force weights 10 and the outer diameter of the second shaft 2 ( FIG. 5 ). Here, as a function of the centrifugal force generated by the rotational speed of the second shaft 2 on the centrifugal force weights 10 on the followers 12 on the inclined surfaces 14 , 15 , an axial adjusting force is transmitted onto the shift sleeve 3 . In this way, this sleeve is displaced axially along the first shaft 1 against the restoring spring force of the restoring spring means 16 until force equilibrium is achieved between the axial adjusting force and restoring spring force on the shift sleeve 3 . For an axial displacement of the shift sleeve 3 , this is guided axially on the projections 8 on their inner diameter in the longitudinal grooves 9 on the outer diameter of the first shaft 1 and in the longitudinal grooves 7 on their outer diameter on the projections 6 on the inner diameter of the hub-shaped end section 5 of the clutch housing.
[0038] For further increase in the rotational speed of the second shaft 2 , the shift sleeve 3 is displaced farther along the first shaft 1 in the direction away from its end or the second shaft 2 until the rotational speed of the second shaft 2 increases to a predetermined rotational speed and the end position of the shift sleeve 3 is reached ( FIG. 6 ). Here, the tab-shaped projections 8 on the inner diameter of the shift sleeve 3 engage in a ring-shaped, surrounding recess 19 or annular groove axially limiting the longitudinal grooves 9 on the outer diameter of the first shaft 1 . Therefore, the positive fit in the circumferential direction between the first shaft 1 and shift sleeve 3 is disengaged, wherein this is moved into a position where it can rotate freely on the first shaft 1 . Therefore, the first and second shafts 1 , 2 are decoupled and the clutch arrangement is located in an open state.
[0039] With decreasing rotational speed of the second shaft 2 , the centrifugal force acting on the centrifugal force weights 10 and thus the axial adjusting force transmitted to the shift sleeve 3 are reduced. Until a force equilibrium is reached between this and the restoring spring force of the restoring spring means 16 , the shift sleeve 3 is shifted back in the direction of the second shaft and therefore the clutch arrangement is transferred back into its closed state. Here, the projections 8 on the inner diameter of the shift sleeve are pressed by the restoring spring force of the restoring spring means 16 from the ring-shaped recess 19 on the outer diameter of the first shaft 1 back into the longitudinal grooves 9 . Here, the closing of the clutch arrangement can be supported with control means by the electric motor driving the first shaft 1 as the engine shaft. For this purpose, the rotational speed of the engine shaft is adapted by the rotational speed control of the electric motor to the rotational speed of the second shaft 2 forming the transmission shaft. When the rotational speeds of the engine shaft and transmission shaft match, these are in a torque-free state relative to each other. Therefore, the projections 8 on the inner diameter of the shift sleeve 3 can be pressed out of the ring-shaped recess 19 on the outer diameter of the engine shaft free from forces and thus free from friction into the longitudinal grooves 9 by the restoring spring force.
LIST OF REFERENCE NUMBERS
[0000]
1 Shaft
2 Shaft
3 Shift sleeve
4 End section
5 End section
6 Projection
7 Recess
8 Projection
9 Recess
10 Centrifugal force weight
11 Section
12 Follower
13 Rotational axis
14 Inclined surface
15 Inclined surface
16 Restoring spring means
17 Axial bearing
18 Securing element
19 Recess | A clutch arrangement for a vehicle for the purpose of detachably connecting two shafts ( 1, 2 ), characterized in that at least one shift sleeve ( 3 ) arranged in coaxially displaceable fashion on a shaft ( 1, 2 ) can, under centrifugal force actuation as a function of the increase in the rotational speed of a shaft ( 1, 2 ), be displaced from a position in which it provides rotationally locked coupling for the purpose of connecting the shafts ( 1, 2 ) into a position in which it decouples the shafts ( 1, 2 ). The invention also relates to a method for operating a vehicle. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the National Phase of International Application No. PCT/AU98/00944, filed Nov. 12, 1998, which claims benefit of Australian Application No. PP 0328, filed Nov. 12, 1997.
FIELD OF THE INVENTION
THIS INVENTION relates generally to carrier-reporter bead assemblies and their use in relation to oligomer libraries which may be formed by a combinatorial split-process-recombine procedure as well as a method for decoding molecules produced in such oligomer libraries.
BACKGROUND OF THE INVENTION
Split-process recombine methods in combinatorial chemistry are already known in relation to formation of peptide libraries as discussed in Gallop et al., 1994, J. Med. Chem. 37 1233-1251 which refers to synthesis of peptide libraries by the use of polystyrene beads which are initially present as a first batch which are split into smaller batches wherein different amino acids are covalently attached to a primary linker group present on the surface of each bead. Subsequently, the beads are recombined and then split again so that a second amino acid may be attached to the amino acid attached to the primary linker group. This process is repeated a number of times as may be required to produce the peptide library.
A similar procedure is described in Gallop et al., 1994, supra which refers to the establishment of an oligonucleotide library.
“Split-process-recombine” or “split synthesis” methods generating one (resin) bead-one compound libraries were first proposed in Furka et al., 1991, Int. J. Pept. Protein Res. 37 487-493 and are also discussed in Eichler et al., 1995, Medicinal Research Reviews 15(6) 481-496 and Balkenhohl et al., 1996, Angew. Chem. Int. Ed. Engl. 35 2288-2337.
Peptide libraries are mainly used in drug discovery as discussed in Gallop et al., 1994, supra wherein potentially useful drugs are identified by screening methods as are known in the art. This is also reported in Borman Chemical & Engineering News, February 1997, 43-62, Fruchtel et al., 1996, Angew. Chem. Int. Ed. Engl. 35 17-42 and Barany et al., 1987, In. J. Peptide Protein Res. 30 705-739.
Oligonucleotide libraries, on the other hand, are useful as a tool for rapid DNA sequencing by hybridization as discussed in Fodor et al., 1991, Science 251 767, Lysov et al., 1988, Dokl. Akad. Nauk. SSSR 303 1508, Bains et al., 1988, J. Theor. Biol. 135 303, Drmanac et al., 1989, Genomics 4 114 and Drmanac et al., 1993, Science 260 1649.
Sequencing by hybridization (SBH) has been proposed to replace conventional DNA sequencing technology which is a laborious procedure involving electrophoretic size separation of labelled DNA fragments. SBH uses a set of short oligonucleotide probes of defined sequence to search for complementary sequences on a longer target strand of DNA. The hybridization pattern is used to reconstruct the target DNA sequence.
The challenge with implementing SBH techniques as a viable method of sequencing of DNA is that an extremely large number of probes is required. New methods have been proposed to overcome this problem as discussed in Fodor et. al., 1991, supra, Pease et al., 1994, Proc. Natl. Acad. Sci. 91 5022, Cho et al., 1993, Science 261 1303 and Southern et al., 1992, Genomics 13 1008. These new methods involve the use of oligonucleotide arrays or “biological chips” as discussed in Fodor et al., 1991, supra, which harbour specified chemical compounds (i.e. the probes) at precise locations in an array format. The target DNA is then added to the array of probes. The hybridization pattern, determined in a single experiment, directly reveals the identity of all complementary probes as reported in Drmanac et al., 1989, supra and Drmanac et al., 1993, supra. Although this technique holds much promise, the information density on each array is extremely low for the purpose of DNA sequencing and this limits the size and speed with which DNA fragments can be sequenced. The difficulties associated with selectively anchoring oligonucleotide sequences to specific and spatially arranged sites on the substrate means that the minimum pixel size in the arrays is limited currently to approximately 0.4 mm×0.4 mm in area. As pixel size directly determines information density and hence sequencing efficiency, miniaturization of the “biological chips” is a major technical problem for implementing this technology as a rapid method of sequencing. One method of overcoming this problem is the use of a technique requiring “field induced colloidal crystallization” as reported in Trau et al., 1996, Science 272 706. This technique uses miniaturized chips of patterned microscopic colloidal particles which contain chemisorbed oligonucleotides on a transparent electrode comprising indium tin oxide. Fluorescent hybridization patterns of unknown DNA sequences with the arrays are observed using an optical microscope.
Before the advent of the technique of Trau et al., 1996, supra, SBH was previously carried out by attaching target DNA to a surface and sequentially interrogating with a set of oligonucleotide probes, one at a time as discussed in Drmanac et al., 1989, supra, Drmanac et al., 1993, supra and Strezoska et al., 1991, Proc. Nat. Acad. Sci. USA 88 10089 which was time consuming and inefficient.
Application of conventional split-process-recombine methods to drug discovery and SBH is, however, currently limited by the inherent difficulty of rapidly, and conveniently, identifying the unique sequence of events applicable to any chosen multimeric molecule. For large numbers of carriers and large numbers of steps and/or processing methods, this “identification” procedure is particularly difficult. In many practical cases, where high throughput and fast analysis is required, this problem is intractable by conventional methods.
The conventional split-process-recombine technologies referred to above presented difficulties when it was desired to detect and isolate a molecule of interest. In this regard, it was necessary to detect the molecule of interest by use of a suitable assay or probe and then isolate the molecule of interest by cleaving that molecule from the bead and subsequently identifying the molecule by techniques such as mass spectroscopy or HPLC. This was time consuming and cumbersome and in some cases, cleavage was not possible.
Reference may be made to International Publication WO93/06121 which refers to a general stochastic method for synthesizing libraries of random oligomers, which are synthesized on solid supports inclusive of polystyrene beads or which may be cleaved from these supports to provide a soluble library. The oligomers are composed of a sequence of monomers that can be joined together to form an oligomer or polymer. This reference also describes the use of identifier tags to identify the sequence of monomers in the oligomer. The identifier tag may be attached directly to the oligomer with or without an accompanying particle, to a linker attached to the oligomer, to the solid phase support on which the oligomer is synthesized or to a second particle attached to the oligomer carrying particle. However, the only means of attachment described in this reference is by way of covalent bonding. In this reference, the identifier tag is described in very broad terms, such as any recognizable feature, which includes a microscopically distinguishable shape, size, colour or optical density; a differential absorbance or emission of light; chemical reactivity; magnetic or electronic coiled information; or any other distinctive mark with the required information and decipherable at the level of one or a few solid supports. In one form, the identifier tags are described as small beads of recognizably different shapes, sizes or colours or labelled with bar codes.
However, while the description of International Publication WO93/06121 refers very broadly to the types of identifier tags that may be utilized in the method of formation of oligomer libraries, the only experimental evidence referred to in the specification is the use of oligonucleotides. Thus, there is no enabling disclosure especially in relation to the use of small beads as identifier tags and how this particular technique may be put into practical effect.
In International Publication WO93/06121, reference is made to identifying the tags by sequencing or hybridization if the tag is an oligonucleotide. One can also amplify the oligonucleotide tag by PCR. However, it will be appreciated that such identification methods are time consuming and inefficient. For example, use of PCR may result in PCR product contamination making it necessary to introduce further measures to overcome this problem as described in International Publication No. WO93/06121. It is also necessary to sequence amplified DNA and this involves an additional step in the identification procedure as described in International Publication No. WO93/06121.
Reference may also be made to U.S. Pat. No. 5,721,099 which describes complex combinatorial chemical libraries of compounds encoded with tags. Each compound in the library is produced by a single reaction series and is bound to an individual solid support which may include particles or beads inclusive of polystyrene beads or silica gel beads. Each solid support has bound to it a combination of four distinguishable identifiers which differ from one another. The combination provides a specific formula comprising a tag component capable of analysis and a linking component capable of being selectively cleaved to release the tag component. Each identifier or combination thereof encodes information at a particular stage in the reaction series for the compound bound to the solid support. However, it is essential in this library that prior to analysis, each tag component must be cleaved from the support thus creating at least one additional step which is time consuming and inefficient and thus the same disadvantages relevant to International Publication WO93/06121 also apply in the case of this reference.
In relation to using single stranded identifier tags to encode combinatorial peptide synthesis, which method is discussed in Needles et al., 1993, Proc. Natl. Acad. Sci. U.S.A. 90 10700-10704, such method was disadvantageous because of the reasons discussed above in International Publication WO93/06121. However, it is also noted that after detection of a peptide or molecule within the library of interest, in some cases it was necessary to cleave the corresponding tag from the support and amplify the tag by PCR because it was only present in trace amounts. This was also time consuming and inefficient.
Reference may also be made to photolabile or electrophoretic tagging as described in Ohlmeyer et al., 1993, Proc. Nat. Acad. Sci. USA 90 10922-10926 or Gallop et al., 1994, supra which was also disadvantageous because of the inclusion of additional steps prior to identification of the tag.
OBJECT OF THE INVENTION
It is therefore an object of the present invention to provide an assembly of a carrier and one or more reporter beads which assembly may be used to form a synthetic oligomer library suitably, although not exclusively, by a combinatorial split-process-recombine procedure.
Another object of the invention is to provide an oligomer library wherein a molecule of interest in the library may be directly identified or decoded without the requirement of any preliminary step as was the case in the prior art.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided an assembly of a carrier having one or more reporter beads non-covalently attached thereto.
Such an assembly may be used in many applications, such as combinatorial chemistry procedures which do not involve a split-process-recombine procedure. Preferably, however, such assemblies are used in combinatorial chemistries which do involve a split-process-recombine procedure.
According to another aspect of the invention, there is provided a method of forming the above assembly including the step of non-covalently attaching one or more reporter beads to a carrier.
According to yet another aspect of the invention, there is provided a method for forming a synthetic oligomer library comprising a plurality of molecules comprising a multiplicity of different chemical groups, said method including the steps of:—
(i) attaching a respective chemical group to a carrier in each of a plurality of reaction vessels; (ii) attaching a reporter bead to the carrier in non-covalent manner in each reaction vessel wherein each reporter bead has a marker associated therewith; (iii) combining the carriers from each reaction vessel resulting from steps (i) and (ii) into a recombination vessel; (iv) splitting the carriers from the recombination vessel into the plurality of reaction vessels wherein steps (i) and (ii) are repeated; and (v) repeating steps (iii) and (iv) until the library of molecules is formed wherein each molecule will have a unique signal associated therewith which signal is dependent on different combinations of markers to facilitate direct identification of the sequence of chemical groups comprising said molecule;
wherein step (ii) can be carried out prior to or simultaneously with step (i).
It will be appreciated having regard to the above that the term “chemical group” refers to the chemical units or entities that are added one at a time in regard to the synthesis of the molecule. For example, in relation to the formation of an oligopeptide or polypeptide, it is the individual amino acids that comprise the chemical groups. In another example, in relation to the synthesis of an oligonucleotide, it is the basic nucleotides or building blocks of the oligonucleotide that comprise the chemical groups.
The invention in further aspect refers to an oligomer library comprising a plurality of different molecules having a multiplicity of different chemical groups which has been formed by the aforementioned method.
The invention in yet a further aspect refers to an oligomer library comprising a plurality of different molecules wherein each molecule is attached to a respective carrier and wherein there is also provided a plurality of reporter beads attached to the carrier and/or to adjacent reporter beads in non-covalent manner characterized in that each reporter bead has a marker associated therewith to identify the chemical group attached to the carrier as well as to identify the position in sequence of the chemical group relative to other chemical groups in each molecule whereby each molecule in the library will have a unique signal associated therewith which signal is dependent on different combinations of markers to facilitate direct identification of each molecule.
The use of the term “direct” in this context means that each molecule can be identified without the necessity of any preliminary step inclusive of cleaving of the molecule from the carrier and amplification by PCR or by use of hybridization or sequencing as was the case with the prior art, particularly International Publication WO93/06121.
The advantage of direct identification of each molecule means that such molecule can then be synthesized in conventional manner once the unique combination of chemical groups associated with each molecule is known.
In regard to the prior art, it will be appreciated that efficient direct identification or decoding of a molecule of interest could not occur because molecular tags which were covalently bonded to the carrier were not usually detectable unless they were cleaved from the carrier or amplified in the case of nucleic acids. The use of molecular tags also severely limits the maximum possible size of chemical libraries which can be encoded. Although reference was made in the prior art that small reporter beads could be attached to larger carrier beads, this was not enabled, and apart from covalent attachment, no method of achieving this outcome was suggested. In reality, permanent attachment of reporter beads to carriers could not be achieved unless non-covalent forces were taken into consideration, as is the case of the present invention.
It has now been ascertained in accordance with the present invention that by attaching a reporter bead to a carrier in a non-covalent manner that efficient attachment or adherence of the reporter bead to the carrier may be achieved so as to facilitate direct identification or decoding of a molecule of interest within the oligomer library. One example of non-covalent attachment is the use of electrostatic forces wherein surface charges may be induced on either the carrier, reporter bead or both.
However, for the sake of convenience, it has been elucidated by the inventors that use of colloidal particles as reporter beads greatly facilitates non-covalent attachment of the reporter beads to the carrier. A suitable definition of colloidal particles is referred to in Hunter (R. J. Hunter, 1986, “Foundations of Colloid Science”, Oxford University Press, Melbourne, which is incorporated herein by reference).
Thus, when one substance dissolves in another to form a true solution, the ultimate particles of the solute are of molecular dimensions. The radius of the solute molecule in these cases is seldom more than a nanometer and usually less. Solvent and solute molecules are of comparable size and the solute molecules are usually dispersed uniformly through the (continuous) solvent. There is an important class of materials, however, in which the units that are dispersed through the solvent are very much larger in size than the molecules of the solvent. Such systems are called colloidal dispersions. The large particles present in such systems are referred to as colloids.
The size of such colloids varies greatly (depending on the system under study). Typically, a colloidal particle is defined as any particle (i.e., piece of matter) which possesses one microscopic size dimension (i.e., one dimension smaller than that visible by the naked eye). A feature of colloidal systems is that the area of contact between the disperse particles and the dispersion medium, or between more than one dispersed particle, is relatively large.
Because of their macroscopic nature, colloidal particles exhibit interaction forces which are quite different to those of molecular systems. By colloidal forces, we refer to the standard definition used in text books such as Hunter, 1986, supra or Russel et al., 1989, “Colloidal Dispersions”, Cambridge University Press, Cambridge, which is also incorporated herein by reference.
As such particles approach each other, or as they approach some other surface, they will be subject to a variety of macroscopic (i.e., non-covalent) physical forces. Examples of such forces, although by no means an exhaustive list, include:—
(i) van der Waals forces (attractive forces resulting from an intrinsic van der Waals interaction between colloids); (ii) electrostatic forces (attractive or repulsive interaction resulting from surface charge on the colloidal particles); (iii) steric forces (attractive or repulsive interaction resulting from a surface coating of polymers); and (iv) bridging flocculation (attractive forces resulting from the interchange of adsorbed polymer strands from one colloid to another).
It will also be appreciated that non-covalent attachment of reporter beads to carriers has significant advantages when compared to covalent attachment of reporter beads and molecular tags to carriers. Thus, non-covalent attachment of reporter beads to carriers works because of the harnessing of colloidal forces. Covalent attachment without optimisation of the colloidal forces involved of reporters to carriers may not survive the processes associated with combinatorial synthesis. Reporters as small beads need to be sufficiently large to contain enough fluorophores (for example) to be detected easily (i.e., at least 500 fluorophore molecules per bead). This means the beads need to be much larger than a molecule which undergoes a covalent bond. If the small beads were covalently attached to a carrier, then there would be only a few bonds holding a relatively larger reporter. The small beads would be detached very quickly by abrasion against other carriers if there were no colloidal (i.e. non-covalent) forces involved.
The non-covalent attachment does not interfere with the chemical synthesis apart from occupying a portion of available surface area. Covalent attachment of tags, as was the case with the prior art discussed above, means performing extra chemical steps at each stage of the chemical process.
The non-covalent attachment of small beads to the carrier can be performed relatively easily by mixing carriers with reporters in a solvent. The use of non-covalently attached reporters means that there are no artifacts being produced within the tags or ligands by interaction between them. Also, the small reporter beads do not require cleaving and chemical analysis for decoding. This saves time and money.
The invention also has a capacity to determine the sequence of reaction steps when larger numbers of processes or steps are involved as described in detail hereinafter.
It will also be appreciated that the number of markers which can be used is relatively small and, in most cases, can be equal to nine or less as will also be apparent from the following description.
The term “oligomer” as used herein has the same meaning as discussed in International Publication WO93/06121 which is herein incorporated by reference and thus may comprise a sequence of monomers which are any member of a set of molecules that can be joined together to form an oligomer or polymer, i.e., amino acids, carbonates, sulfones, sulfoxides, nucleosides, carbohydrates, ureas, phosphonates, lipids, esters or combinations thereof.
The term “oligomer” as used herein also includes within its scope a plurality of inorganic units attached to each other in a particular sequence. Examples of inorganic units are silicates and aluminosilicates.
The invention in another aspect also includes a process of decoding molecules which are encoded by the process of the invention which includes the step of analysis of the reporter beads as described hereinafter so as to determine the unique sequence of the chemical groups which comprise each of the molecules.
It therefore will be appreciated that, in another aspect of the invention, there is provided a process for identification of a particular molecule having a certain unique sequence by the decoding process described above.
It will also be appreciated that while the preferred embodiment described hereinafter refers to the formation of oligonucleotides or oligopeptides wherein nucleotides or amino acids correspond to the chemical groups as discussed above, the process of the invention is applicable to the formation of oligomers or polymers from identical monomer units or formation of relatively complex molecules or macromolecules from individual or different chemical groups or components as will be apparent from the meaning of “oligomer” discussed above.
In particular, the process of the invention is applicable to any type of chemical reaction that can be carried out on a solid support and thus includes, for example:—
(i) [2+2] cycloadditions including trapping of butadiene; (ii) [2+3] cycloadditions including synthesis of isoxazolines, furans and modified peptides; (iii) acetal formation including immobilization of diols, aldehydes and ketones; (iv) aldol condensation including derivatization of aldehydes, synthesis of propanediols; (v) benzoin condensation including derivatization of aldehydes; (vi) cyclocondensations including benzodiazepines and hydantoins, thiazolidines, β-turn mimetics, porphyrins, phthalocyanines; (vii) Dieckmann cyclization including cyclization of diesters; (viii) Diels-Alder reaction including derivatization of acrylic acid; (ix) electrophilic addition including addition of alcohols to alkenes; (x) Grignard reaction including derivatization of aldehydes; (xi) Heck reaction including synthesis of disubstituted alkenes; (xii) Henry reaction including synthesis of nitrile oxides in situ (see [2+3]cycloaddition); (xiii) catalytic hydrogenation including synthesis of pheromones and peptides (hydrogenation of alkenes); (xiv) Michael reaction including synthesis of sulfanyl ketones, bicyclo]2.2.2]octanes; (xv) Mitsunobu reaction including synthesis of aryl ethers, peptidyl phosphonates and thioethers; (xvi) nucleophilic aromatic substitutions including synthesis of quinolones; (xvii) oxidation including synthesis of aldehydes and ketones; (xviii) Pausen-Khand cycloaddition including cyclization of norbornadiene with pentynol; (xix) photochemical cyclization including synthesis of helicenes; (xx) reactions with organo-metallic compounds including derivatization of aldehydes and acyl chlorides; (xxi) reduction with complex hydrides and Sn compounds including reduction of carbonyl, carboxylic acids, esters and nitro groups; (xxii) Soai reaction including reduction of carboxyl groups; (xxiii) Stille reactions including synthesis of biphenyl derivatives; (xxiv) Stork reaction including synthesis of substituted cyclohexanones; (xxv) reductive amination including synthesis of quinolones; (xxvi) Suzuki reaction including synthesis of phenylacetic acid derivatives; and (xxvii) Wittig, Wittig-Horner reaction including reactions of aldehydes; pheromones and sulfanyl ketones.
Reference may also be made to Patel et al., April 1996, DDT 1(4) 134-144 which refers to manufacture or synthesis of N-substituted glycines, polycarbamates, mercaptoacylprolines, diketopiperazines, HIV protease inhibitors, 1-3 diols, hydroxystilbenes, B-lactams, 1,4-benzodiazepine-2-5-diones, dihydropyridines and dihydropyrimidines.
Reference may also be made to synthesis of polyketides as discussed in Rohr, 1995, Angew. Int. Ed. Engl. 34 881-884.
The carriers for use in the method of the invention are suitably polymeric supports such as polymeric beads which are preferably formed from polystyrene crosslinked with 1-5% divinylbenzene. Carrier beads may also be formed from hexamethylenediamine-polyacryl resins and related polymers, poly[N-{2-(4-hydroxylphenyl)ethyl}] acrylamide (i.e. (ONE Q)), silica, cellulose beads, polystyrene beads, latex beads, grafted copolymer beads such as polyethylene glycol/polystyrene, pore-glass beads, polyacrylamide beads, dimethylacrylamide beads optionally cross-linked with N,N′-bis-acrylolyl ethylene diamine, glass particles coated with a hydrophobic polymer inclusive of cross-linked polystyrene or a fluorinated ethylene polymer which provides a material having a rigid or semi-rigid surface, poly(N-acryloylpyrrolidine) resins, p-benzyloxybenzyl alcohol resin (WANG resin), 4-hydroxymethylphenylacetamidomethyl resin (PAM resin), chloromethylpolystyrene-divinylbenzene resin (MERRIFIELD resin), polyethylene glycol/polystyrene resin (PAP resin), polyamide resin, polyethylene functionalized with acrylic acid, kieselguhr/polyamide (Pepsyn K), polyacrylamide/polystyrene copolymer (POLYHIPE), polystyrene/polydimethylacrylamide copolymers, controlled pore glass (CPG), polystyrene macrobeads, polystyrene/polyethylene glycol (TENTAGEL) and polyethylene glycol-polystyrene/divinylbenzene copolymers.
These carrier materials will usually contain functionalities or be able to be functionalized for attachment of reporter beads or linkers. Suitable functionalities include —NH 2 , —COOH, —SOH, —SSH or sulfate groups.
It will also be appreciated that the polymeric beads may be replaced by other suitable supports such as pins or chips as is known in the art, e.g. as discussed in Gordon et al., 1994, J. Med. Chem. 37(10)1385-1401. The beads may also be replaced by pellets, discs, capillaries, hollow fibres or needles as is known in the art.
Thus, it can be appreciated from the foregoing that the carrier may comprise any solid material capable of providing a base for combinational synthesis.
Reference is also made to International Publication WO93/06121, which is incorporated herein by reference, which describes a full range of supports that may constitute carriers for use in the method of the invention which may have any suitable shape and be formed from appropriate materials inclusive of latex, glass, gold or other colloidal metal particles and the like.
Reference may also be made to International Publication WO95/25737 or WO97/15390 which are herein incorporated by reference to examples of suitable carriers.
Linkers for use with the supports of the inventions may be selected from base stable anchor groups as described in Table 2 of Fruchtel et al., 1996, supra or acid stable anchor groups as described in Table 3 of Fruchtel et al., 1996, supra. In this regard, the Fruchtel et al., 1996, reference is incorporated herein by reference.
Linkers for use in the method of the invention are also referred to in International Publication WO93/06121.
Generally the anchors developed for peptide chemistry are stable to either bases or weak acids but for the most part, they are suitable only for the immobilization of carboxylic acids.
However, for the reversible attachment of special functional groups, known anchors have to be derivatized and optimized or, when necessary, completely new anchors must be developed. For example, an anchor group for immobilization of alcohols is (6 hydroxymethyl)-3,4 dihydro-2H-pyran, whereby the sodium salt is covalently bonded to chloromethylated Merrifield resin by a nucleophilic substitution reaction. The alcohol is coupled to the support by electrophilic addition in the presence of pyridinium toluene-4 sulphonate (PPTS) in dichloromethane. The resulting tetrahydropyranyl ether is stable to base but can be cleaved by transetherification with 95% trifluoroacetic acid.
Benzyl halides may be coupled to a photolabile α-sulphanyl-substituted phenyl ketone anchor.
It will also be appreciated that the markers for use in the method of the invention include, but not necessarily limited to, fluorophores, chromophores, bar codes or radioactive or luminescent labels as discussed in International Publication WO93/06121. The markers may also include detectable physical features of the beads such as the size of the beads. Preferably, the markers comprise fluorescent dyes. Any suitable fluorescent dye may be used for incorporation into the reporter beads of the invention. For example, reference may be made to U.S. Pat. Nos. 5,573,909 (Singer et al., which is incorporated herein by reference) and 5,326,692 (Brinkley et al., which is incorporated herein by reference) which describe a plethora of fluorescent dyes which may be used in accordance with the present invention.
Reference may also be made to fluorescent dyes described in U.S. Pat. Nos. 5,227,487, 5,274,113, 5,405,975, 5,433,896, 5,442,045, 5,451,663, 5,453,517, 5,459,276, 5,516,864, 5,648,270 and 5,723,218 which are all incorporated herein by reference.
One or more of the fluorescent dyes are preferably incorporated into a reporter bead, such as a polymeric or ceramic microparticle. The polymeric microparticle can be prepared from a variety of polymerizable monomers, including styrenes, acrylates and unsaturated chlorides, esters, acetates, amides and alcohols, including but not limited to, polystyrene (including high density polystyrene latexes such as brominated polystyrene), polymethylmethacrylate and other polyacrylic acids, polyacrylonitrile, polyacrylamide, polyacrolein, polydimethylsiloxane, polybutadiene, polyisoprene, polyurethane, polyvinylacetate, polyvinylchloride, polyvinylpyridine, polyvinylbenzylchloride, polyvinyltoluene, polyvinylidenechloride and polydivinylbenzene. The microparticles may be prepared from styrene monomers. Ceramic microparticles may be comprised of silica, alumina, titania or any other suitable transparent material.
A suitable method of making silica microparticles is described, for example in “The Colloid Chemistry of Silica and Silicates” Cornell University Press by Ralph Keller 1955.
The microparticles may be of any suitable size or shape. For example, the microparticles may be spherical or irregular in shape. Typically, microparticles which may be used in the present invention have a diameter of about 0.01 μm to about 50 μm.
Fluorescent dyes may be incorporated into microparticles by any suitable method known in the art, such as copolymerization of a polymerizable monomer and a dye-containing comonomer or addition of a suitable dye derivative in a suitable organic solvent to an aqueous suspension as, for example, disclosed in Singer et at., supra including references cited therein. Alternatively, fluorescent microparticles may be produced having at least one fluorescent spherical zone. Such microparticles may be prepared as for example described in U.S. Pat. No. 5,786,219 (Zhang et al.) which is incorporated herein by reference.
It will also be appreciated that one may detect or identify a compound of interest in a compound library of the invention having a unique sequence by a number of screening methods well known in the art without the need for cleaving the molecule of interest from the carrier. When the unique sequence has been determined, a molecule comprising such sequence can by synthesized by conventional means such as amino acid synthesizers or oligonucleotide synthesizers as is known in the art.
One may also apply the method of the invention to SBH technology whereby a library is formed of carrier beads, each of which has attached thereto a unique polynucleotide or oligonucleotide sequence and reporter beads identifying the unique sequence. An aqueous solution of fluorescently labelled ssDNA of unknown sequence may be passed over the library of polynucleotide or oligonucleotide compounds and adsorption (hybridization) of the ssDNA will occur only on carrier beads which contain polynucleotide or oligonucleotide sequences complementary to those on the ssDNA. These carrier beads may be identified, for example, by fluorescence optical microscopy.
Ligands that may be screened in accordance with the invention include agonist and antagonists for cell membrane receptors, toxins, venoms, viral epitopes, hormones, sugars, cofactors, peptides, enzyme substrates drugs inclusive of opiates and steroids, proteins including antibodies, monoclonal antibodies, antisera reactive with specific antigenic determinants, nucleic acids, lectins, polysaccharides, cellular membranes and organibles.
BRIEF DESCRIPTION OF THE DRAWINGS
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the U.S. Patent and Trademark Office upon request and payment of the necessary fee.
Reference to a preferred embodiment of the invention is made in the attached drawings, wherein:—
FIG. 1 is a schematic representation of one step in a split-process-recombine procedure, e.g. as discussed in the prior art in relation to the synthesis of peptide libraries;
FIG. 2 is a schematic representation of the entire iterative split-process-recombine procedure referred to in FIG. 1 ;
FIG. 3 is a schematic representation of one step in the split-process-recombine procedure of the invention which includes reporter bead tagging;
FIG. 4 is an illustrative example of reporter beads attached to a carrier particle wherein there is shown an optical microscope image of three 0.9 μm silica reporter beads attached to a 2.5 μm silica carrier bead. In this case, attachment was achieved by dissolving NaCl to a mixed aqueous suspension of these particles. The size of reporter beads would typically be much smaller than that of the carrier bead. The image is simply an illustrative example;
FIG. 5 is a schematic of the fluorescence microscope apparatus which may be used for the decoding experiments. The barrier filter (F 1 ) and the excitation filter (F 2 ) are clearly labelled;
FIG. 6 is a schematic diagram of red-tagged and green-tagged carriers, combined to form Population 3 in Procedure D in Example 3 hereinafter. For clarity, the reporters drawn here are much larger than the 1 μm reporters used in the Example;
FIG. 7 is a schematic diagram of Population 4 in Procedure E in Example 3. For clarity, the reporters drawn here are much larger than the 1 μm reporters used in the Example;
FIG. 8 is a schematic diagram of Population 5 in Procedure E in Example 3. For clarity, the reporters drawn here are much larger than the 1 μm reporters used in the Example;
FIG. 9 shows two fluorescence microscopy images (as FIG. 9( a ) and FIG. 9( b )) of a sample of carrier beads after the second tagging and coupling step (a sample of Population 4 in Procedure F in Example 3);
FIG. 10 shows three fluorescence microscopy images (as FIGS. 10( a ), 10 ( b ) and 10 ( c )) of a sample of carrier beads after the second tagging and coupling step (a sample of Population 5 in Procedure F in Example 3);
FIG. 11 shows three fluorescence microscopy images as FIGS. 11( a ), 11 ( b ) and 11 ( c ) of a sample of carrier beads after the second tagging and coupling step (a sample of combined Population 4 and 5 in Procedure G in Example 3;
FIG. 12 is a schematic of combined Populations 4 and 5 in Procedure G in Example 3. For clarity, the reporters drawn here are much larger than the 1 μm reporters used in the Example;
FIG. 13 , as FIGS. 13( a ) and 13 ( b ), show scanning electron micrographs of 0.2 μm particles attached to aminomethylated (˜100 μm) carriers, and (c) 2.5 μm polyelectrolyte coated silica particles attached to an aminomethylated (˜100 μm) carrier;
FIG. 14 shows a confocal fluorescence microscopy image of three carriers, each tagged with 1 μm fluorescent red, 1 μm fluorescent green and 2.0 μm far red fluorescent reporters. The red colours on the micrograph denote the red reporters, the green colours on the micrograph denote the green reporters and the blue colours on the micrograph denote the far red coloured reporters;
FIG. 15 is a schematic of the two step split-process-recombine method in Example 3; and
FIG. 16 is a mass spectrograph of a peptide cleaved off the tagged carriers as described in Procedure J in Example 4. The largest peak is at 626.1 which corresponds to the molecular weight of Fmoc-Alanine-Glycine-Lysine-Glycine-OH (SEQ ID NO:1). This is the exact peptide sequence which was synthesized on the carriers in this three-step amino acid coupling and tagging example.
DESCRIPTION OF PREFERRED EMBODIMENT
A split-process-recombine procedure involving n process s and m steps may be defined as follows. Let the n processes be P 1 , P 2 , . . . , P n . The event of performing process P j at the ith step will be denoted by P j (i). At each stage i=1, 2, . . . , m:
the carriers are partitioned into n subsets S 1 , S 2 , . . . , S n ;
for j=1, 2, . . . , n process P j is performed on the carriers in subset S j ;
the carriers are recombined.
A schematic representation of this procedure is shown in FIGS. 1 and 2 .
Examples of such processes include the combinatorial synthesis of oligonucleotide and oligopeptide chains. In these examples, insoluble polymer beads (colloidal particles, typically 1-1000 μm in diameter) may be used as the carriers onto which nucleic or amino acid monomers are attached and sequentially grown. By performing the split-process-recombine procedure repeatedly for a large number of carriers, a large variety of randomly generated oligonucleotide or oligopeptide sequences can be synthesized. Each carrier thus contains an attached polymer with a unique sequence which is defined by the sequence of processing events which the carrier has experienced (i.e., the specific path which the carrier has followed in FIG. 2 ).
The present invention relates to a novel and convenient method to determine the sequence of processes applied to a particular carrier involved in a split-process-recombine procedure. This procedure does not involve the chemical tagging of the carrier and by contrast involves the tagging of carriers by non-covalent attachment of reporter beads. This method has several significant advantages over conventional tagging methods:—
(1) Attachment of beads to the carrier can be achieved by simple (physical) processes which do not necessarily involve chemical reactions. Consequently it is extremely unlikely that the tagging procedure will interfere with the reaction processes under study. (2) The reporter beads may be doped (i.e., imbibed) with a wide variety, and high concentration, of reporter molecules (e.g., fluorescence dyes) to enable facile detection and multi-step tagging without the necessity of chemical grafting, cleaving, and/or amplification. (3) The presence of beads attached to the carrier is extremely easy to detect via a number of means (e.g., fluorescence emission, infrared spectroscopy). This allows facile and convenient determination of the processing sequences which a carrier has experienced.
A method by which the sequence of processes applied to a particular carrier involved in a split-process-recombine procedure can be determined at the conclusion is now described.
For i=1, 2, . . . , m and for j=1, 2, . . . , n a batch B j (i) of reporter beads is required. These reporter beads will have the property that the batch to which any particular reporter bead belongs can be determined from the properties of the bead. Examples of possible properties which may be used to identify the batch to which a reporter bead belongs include, but are not necessarily limited to, (i) colour; (ii) fluorescence signal; (iii) infrared spectrum; (iv) radioactive tag and (v) detectable physical feature inclusive of size.
At each stage i in the procedure, one or more reporter beads from batch B j (i) is attached to each of the carriers which go through process P j (i). Then at the conclusion of the procedure, the sequence of processes applied to any particular carrier can be determined from the reporter beads which are attached to it as described hereinafter. The order of steps for this is shown schematically in FIG. 3 .
An example of a method for attaching the reporter beads to the carrier beads is as follows. Note that it is possible to attach the reporter beads from batch B j (i) to the carriers before the process P j (i) is performed if this is desirable.
Most of the systems described above may utilize insoluble polystyrene or silica colloidal particles as carriers. In one example, we used a 2.5 μm silica particle as the carrier and 0.9 μm silica particles (obtained from Bangs Laboratories, Carmel, Ind., USA) as reporters. When suspended in aqueous solution (e.g., in Milli-Q ion exchanged water), these particles remain separate from each other by virtue of electrostatic repulsion forces which result from the negative surface charge on each particle. The dissolution of salt (e.g., sodium chloride) in the aqueous solution shields the effect of the electrostatic repulsion between the particles and results in a permanent coagulation (i.e., sticking) of the small particles with the large particles (see FIG. 4 ). Under such conditions, the adhesion of the small particles to the large particles is primarily caused by van der Waals attractive forces which occur between the particles (Hunter supra and Russel et al., supra. Moreover, as has been shown by Healy et al., (1966, Transactions of the Faraday Society 62 1638; 1970, ibid, 66 490), the rate of coagulation of small particles with large particles will always be greater than that of large particles with large particles or small particles with small particles. In an analogous way, the small particles can be attached to the large particles by using a combination of both electrostatic and van der Waals attractive forces. This is the situation for example if the small and large particles are oppositely charged. In such a situation, when a suspension of small particles is mixed with a suspension of large particles, coagulation (permanent adhesion) of small particles to large particles, and vice versa, will occur spontaneously. Such methods of coagulating mixtures of colloidal particles by utilizing physical/chemical interactions are well known to the art and are described in references which include the Hunter reference referred to above. In order to enhance the strength and selectivity of the particle-particle adhesion, chemical additives (e.g., polyelectrolytes) and chemical reactions (e.g., polymer bridging reaction between particles) may be used, however these are not essential. Indeed, as described above, there are significant advantages to tagging the carrier beads with physically attached tags, rather than chemically attached tags.
It will be appreciated that reporter beads may be attached to the surface of a carrier but this is not essential. In this regard, the inventors recognise that it would be possible to attach reporter beads to the inside of a carrier through existing pores of the carrier.
We note that it may be desirable to attach reporter beads to existing reporter beads on the carrier rather than directly onto the surface of the carrier. This may be advantageous in locating the reporter beads during the decoding procedure or it may give extra information as to the order in which the reporter beads were attached. This can be accomplished by utilizing intrinsic physical forces between the reporter beads. One example of how this can be accomplished is to alternate the surface charge on the reporter beads. For example, the first reporter beads to be attached to the carrier particles will have either positive or negative surface charge. The next batch of reporter beads will possess the opposite charge to those previously attached (i.e., positive for negatively charged reporter beads in the first tagging step and vice versa). Altering the surface charge of the reporter beads in this manner will allow reporter beads to attach to other reporter beads as well as to the carrier particles.
It is desirable that any reporter beads which are left in solution (i.e., those which do not attach to a carrier) be removed from the solution before the next step in the procedure. This can be achieved, for example, by allowing the heavier carrier beads to settle to the bottom and removing any non-attached reporter beads by decanting of the solution containing the suspended reporter beads and rinsing with clear solution. To aid this procedure, a charged plate of opposite polarity to that of the carrier beads may be used to attract the carrier beads (with attached reporter beads) whilst repelling the unattached reporter beads.
An example of how reporter bead attachment can be used to determine the sequence of processes performed on any carrier bead is illustrated below.
Let us consider a process which contains 4 steps (i=1, . . . , 4) and 4 processes (j=1, . . . , 4). For example, a 4-step combinatorial oligopeptide synthesis. Each step involves the addition of one amino acid monomer, of a set of four amino acids which are of interest (e.g. alanine, glycine, lysine and methionine). Each process defines which of the 4 possible amino acid monomers is attached. After 4 steps, each carrier will contain a oligopeptide chain with 4 amino acid monomers in random sequence. In this case, the total possible number of sequences is 4 4 (=256).
In order to tag each step and each process uniquely, we need 16 types of reporter beads which will be attached to the carriers before or after each step (according to FIG. 3 ), and can be later uniquely identified. The simplest way of achieving this is to use reporter beads (e.g., 1 μm silica beads) which contain a combination of 4 fluorescent dyes in their interior.
Four convenient fluorescent dyes are Red (R), Yellow (Y), Green (G) and Blue (B). With 4 dyes, there are 16 possible combinations of dye colours which can be incorporated in the reporter beads (i.e., RYGB, RYG, RGB, RYB, YGB, RY, RG, RB, YG, YB, GB, R, Y, G, B, no dye) and so 16 different batches of reporter beads can be manufactured. By attaching one of these beads to the carrier immediately before or after an amino acid addition, the combination of dyes within the reporter bead will code for one unique process and step (i.e., it will define P j (i) in FIG. 3 ).
Detection of the dye combination within the beads can conveniently be achieved with a fluorescence microscope after the entire process is complete. The microscope will have sufficient magnification to observe the individual reporter beads, and appropriate light filters can be used to determine which fluorescent colours (if any) are being emitted from the reporter beads attached to the carrier. Having regard to the above example, if each carrier contains a oligopeptide chain of 4 amino acid monomers, there will be four distinct reporter populations attached to each carrier. This means that once 4 distinct reporter beads are identified on a carrier, the sequence of reaction steps experienced by that carrier is uniquely determined.
Generally, for a split-process-recombine procedure with m steps and n processes, a set of m×n batches of reporter beads is sufficient to uniquely tag the entire process. In the above example, we showed how 16 unique tags could be produced from a combination of 4 fluorescent dyes. This number can be vastly increased by a number of simple schemes:—
(I) Increase the number of fluorescent dyes, with distinct fluorescent signals, incorporated inside the reporter particle. This can be achieved not only by choosing dyes with clearly distinct emission frequencies, but also by choosing dyes with similar emission frequencies, but with clearly distinct excitation frequencies. Fluorescent optical microscopy techniques are available for this purpose (as described in Fluorescent Microscopy by F. W. D. Rost, Cambridge University Press, Vol. 1, 1992 and Introduction to Fluorescent Microscopy by J. S. Ploem and H. J. Tanke, Oxford University Press, 1987). FIG. 5 illustrates how the microscope can be set up. Two particle dyes with similar emission frequencies can be distinguished because of their distinct excitation frequencies. Suppose one dye D 1 emits red light after excitation with green light and another dye D 2 emits red light after excitation with blue light. The microscope set-up shown in the diagram can distinguish the two dyes by changing the filter F 2 to transmit only green light or only blue light. The dye D 1 will emit red light only when green light is passed through F 2 . The dye D 2 will emit red light only when blue light is passed through F 2 . Different coloured dyes within the particles can be detected by changing the transmitting frequency of filter F 1 . Judicious choice of such dyes will increase the number of reporter dyes from 4 to greater than 20. (II) The size of the reporter bead can be varied in order to increase the possible number of tags. (e.g., if two different sizes are used for reporter beads, the number of possible tags is doubled) (III) The concentration of fluorescent dye within each reporter bead can be varied. Different concentrations will give rise to different emission intensities (e.g., two different dye concentrations within the reporter beads will double the number of possible tags).
The capacity of this technique to determine the sequence of reaction steps when larger numbers of processes and steps are involved is clearly demonstrated by the following argument. If x different fluorescent dyes can be incorporated in a reporter bead then the number of different batches of reporter beads which can be manufactured is 2 x . With 2 x distinct batches of reporter beads it is possible to trace the sequence of reaction steps performed on a carrier provided the product n×m of the number of processes with the number of steps is less than 2 x . Even though the number of possible sequences of reactions performed on a carrier is n m , the technique requires at most log 2 (n×m) different dyes. This value or number is rounded out to the nearest integer above or equal to this value. For example, if 20 processes (as would be the case for 20 amino acids involved in polypeptide synthesis) and 25 reaction steps are involved then there are 20 25 ≈3×10 32 possible sequences but only 9 different dyes are required.
Although this example specifies fluorescence as the detection method for the reporter beads, many other reporting and detection methods can also be envisaged. Examples of these include doping the reporter beads with materials which have unique infrared and radioactive signals. These could be used either independently, or in combination with the fluorescent reporter molecules.
For the 4×4 combinatorial oligopeptide synthesis described above, the following procedure as described in Example 1 is used to synthesize and tag.
EXAMPLE
Example 1
Carrier beads used for this procedure are N-α-Boc (t-butyl oxy carbonyl) protected amino acid 4-hydroxymethylphenylacetamidomethyl resin (PAM-resin) (available from Novabiochem). These carrier particles (100-200 mesh) are a standard support for solid phase combinatorial synthesis. In this example, we chose the N-α-Boc-Ala-OCH 2 -4-hydroxymethylphenylacetamidomethyl resin (PAM resin) which contains a protected alanine amino acid residue attached to the surface (other amino acid residues may also be chosen to begin the sequence). All synthesis steps in the split-process-recombine procedure were carried out on a 0.2 mmol scale as follows. The N-α-Boc group was removed by treatment with 100% TFA (trifluoro acetic acid) for 2×1 minute followed by a 30 second flow wash with DMF (dimethyl formamide). Boc amino acids (0.8 mmol) were coupled, without prior neutralization of the peptide-resin salt, as active esters preformed in DMF with either hydroxy benzyl triazol (HOBt)/N,N′-diisopropyl carbodiimide (DIC) (30 minutes activation), or a HBTU/diisopropyl ethyl amine (DIEA) (2 minutes activation) as activating agents. For couplings with active esters formed by HOBt/DIC, neutralization was performed in situ by adding 1.5 equiv. DIEA relative to the amount of TfaO— + NH3-peptide-resin salt to the activated Boc-amino acid resin mixture. For couplings with active esters formed from HBTU/DIEA, an additional 2 equiv. DIEA relative to the amount of TfaO −+ NH3-peptide-resin salt were added tot the activation mixture. Coupling times were 10 minutes throughout without any double coupling. Samples (3-5 mg) of peptide resin were removed after the coupling step for determination of residual-amino groups by the quantitative ninhydrin method. Coupling yields are typically 99.9%. All operations were performed manually in a 20 mL glass reaction vessel with a telfon-lined screw cap. The peptide-resin was agitated by gentle inversion on a shaker during the N-α-deprotection and coupling steps. Prior to recombining and splitting the beads according to the diagram in FIG. 2 , reporter beads (1 μm diameter silica particles) were attached to the resin-peptide carrier beads via the procedures described above (i.e., coagulation in aqueous solution induced with high concentrations (approximately 1 molar) of sodium chloride salt). After peptide additions (i.e., 4-steps) reporter particles remained adhered to the carrier beads.
As well as this limiting example of combinatorial polypeptide synthesis, our coding/decoding method is generally applicable to all solid phase combinatorial chemistry. Other examples of such processes include polynucleotide and cyclic polypeptide synthesis.
Example 2
Preparation of Reporter Suspensions
Fluorescent silica microspheres (10 mg, 1 μm diameter, red or blue or green or yellow/red combination, Microcaps) are coated with polyelectrolytes. The first step is to coat the silica with positively charged polyethyleneimine (PEI) by sonicating for 30 minutes in a 1% aqueous solution of PEI (3 ml, Polysciences Inc., MWt=10000 g/mol) and equilibrating for 24 hours. After washing with reverse osmosis (RO) water (MILLI-Q) by centrifugation (5×3 ml), the silica is added to a 1% aqueous solution of negatively charged polyacrylic acid (PAA, 3 ml, Sigma-Aldrich, MWt=250000 g/mol), equilibrated for 24 hours and washed with RO water (MILLI-Q) by centrifugation (5×3 ml).
The polyelectrolyte coated silica beads are washed with dimethylformamide (i.e., DMF) (5×10 ml) and used as a suspension in DMF (10 mg/ml).
Example 3
Preparation of a Tagged Library
Procedure A: Tagging the Carrier Beads
Cross-linked PS/DVB dry resin beads (aminomethylated, 75-150 μm in diameter, 200 mg, 0.26 mmol/g, Peptide Institute) is split into two 100 mg portions.
One portion is mixed with 0.25 ml of red polyelectrolyte-coated silica reporters (10 mg/ml) in DMF (Population 1) and, similarly, the other portion is added to 0.250 ml green polyelectrolyte-coated silica reporters 910 mg/ml) in DMF (Population 2). Refer to Example 2 for preparation of polyelectrolyte-coated silica reporters.
Procedure B:
The resin is washed with excess DMF (20×20 ml). The solvent and free reporters are removed by vacuum filtration through a glass sinter of pore size 17-40 μm. After the final wash, the resin remains in DMF.
Procedure C:
The monomer Fmoc-Glycine-OH (150 mg, 0.5 mmol, Novabiochem) is mixed with N-[1H-(benzotriazol-I-yl)(dimethylamino)methylene]-N-methylmethanaminimum hexafluorophosphate N-oxide (HBTU, 0.5 mmol, 0.5 M, 1 ml) and diisopropylethylamine (DIEA, 0.6 mmol, 120 μl). The activated amino acid is added to the beads (100 mg) of Population 1 as prepared in Procedure B and shaken for 10 minutes. The resin is washed with DMF (5×20 ml).
The second monomer Fmoc-Alanine-OH (160 mg, 0.5 mmol, Novabiochem) is mixed with HBTU (0.5 mmol, 0.5 M, 1 ml) and DIEA (0.6 mmol, 130 μl). The activated amino acid is added to the beads (100 mg) of Population 2 as prepared in Procedure B and shaken for 10 minutes. The resin is washed with DMF (5×20 ml).
Procedure D:
Population 1 in DMF is combined with Population 2 in DMF to become Population 3, a mixture of red-tagged and green-tagged resins. Population 3 is shaken in DMF for 1 minute to ensure good mixing. FIG. 6 is a schematic of the red-tagged and green-tagged beads in Population 3. Population 3 is split into two 100 mg portions, Population 4 and Population 5.
Procedure E:
A 1 ml suspension of fluorescent yellow/red polyelectrolyte-coated reporters in DMF (10 mg/ml, as prepared in Example 2) is shaken with Population 4 and 1 ml piperidine for 5 minutes. The solvent is removed and a fresh solution of reporters in piperidine/DMF is shaken with the carriers for another 5 minutes. A schematic of Population 4 is shown in FIG. 7 .
A 1 ml suspension of fluorescent blue polyelectrolyte-coated reporters in DMF (10 mg/ml, as prepared in Example 2) is shaken with Population 5 and 1 ml piperidine for 5 minutes. The solvent is removed and a fresh solution of reporters in piperidine/DMF is shaken with the carriers for another 5 minutes. A schematic of Population 5 is shown in FIG. 8 .
Populations 4 and 5 are washed separately with copious amounts of DMF (20×20 ml each) to remove excess reporters.
Procedure F:
The monomer FMOC-Lysine(Boc)-OH (235 mg, 0.5 mmol, Novabiochem) is mixed with HBTU (0.5 mmol, 0.5 M, 1 ml) and DIEA (0.6 mmol, 120 μl). The activated amino acid is added to the beads (100 mg) of Population 4 as prepared in Procedure E and shaken for 10 minutes. The resin is washed with excess DMF (5×20 ml). The relevant images are shown in FIG. 9 .
In the procedure of obtaining the images referred to in FIGS. 9( a ) and 9 ( b ), one species of carrier is tagged with green and yellow/red corresponding to the sequence Lysine-Alanine-carrier and the other species of carrier present is tagged with red and yellow/red reporters-corresponding to the peptide sequence Lysine-Glycine-carrier.
In the top micrograph (a), the sample is excited with blue light (λ=450-480 nm) and emission wavelengths below λ=515 nm are filtered out so that only wavelengths above λ=515 nm are observed.
The predominantly green carriers in (a) are those which have been tagged with fluorescent green reporters in Procedure A in Example 3) and fluorescent yellow/red reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent green and fluorescent yellow reporter beads; the latter being the yellow signals from each combined yellow/red reporter.
The predominantly yellow carriers in (a) are those which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent yellow/red reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent red and fluorescent yellow reporter beads; the latter being the yellow signals from each combined yellow/red reporter.
In the lower micrograph (b), the sample is excited with green light (λ=510-550 nm) and emission wavelengths below λ=590 nm are filtered out so that only wavelengths above λ=590 nm are observed.
The darker (less red) carriers in (b) are those which have been tagged with fluorescent green reporters in Procedure A in Example 3 and fluorescent yellow/red reporters in Procedure E in Example 3. The fluorescent green reporters cannot be observed under this excitation but the red signal from the combined yellow/red reporters can be observed.
The brighter (more red) carriers in (b) are those which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent yellow/red reporters in Procedure E in Example 3. The fluorescent red reporters can be distinguished from the combined yellow/red reporters because the red fluorescence from each red reporter is duller than the red fluorescence from each combined yellow/red reporter.
The monomer FMOC-Arginine(PMC)—OH (304 mg, 0.5 mmol, Bachem) is mixed with HBTU (0.5 mmol, 0.5 M, 1 ml) and DIEA (0.6 mml, 120 μl). The activated amino acid is added to the beads (100 mg) of Population 5 as prepared in Procedure E and shaken for 10 minutes. The resin is washed with excess DMF (5×20 ml). The relevant images are shown in FIGS. 10( a ), 10 ( b ) and 10 ( c ).
In the procedure of obtaining the images referred to in FIG. 10 , one species of carrier is tagged with red and blue reporters corresponding to the peptide sequence Arginine-Glycine-carrier and the other type of carrier present is tagged with green and blue corresponding to the sequence Arginine-Alanine-carrier.
In the top micrograph (a), the sample is excited with light of wavelength (λ=330-385 nm) and emission wavelengths below λ=420 nm are filtered out so that only wavelengths above λ=420 nm are observed.
The green/aqua carriers in (a) are those, which have been tagged with fluorescent green reporters in Procedure A in Example 3 and fluorescent, blue reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent green and fluorescent blue reporter beads.
The red/pink carriers in (a) are those, which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent, blue reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent red and fluorescent blue reporter beads.
In micrograph (b), the sample is excited with blue light (λ=450-480 nm) and emission wavelengths below λ=515 nm are filtered out so that only wavelengths above λ=515 nm are observed.
The predominantly green carriers in (b) are those, which have been tagged with fluorescent green reporters in Procedure A in Example 3 and fluorescent blue reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent green reporter beads. The fluorescent blue reporters cannot be observed under this excitation.
The predominantly yellow carriers in (b) are those, which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent blue reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent red reporter beads. The fluorescent blue reporters cannot be observed under this excitation.
In the lower micrograph (c), the sample is excited with green light (λ=510-550 nm) and emission wavelengths below λ=590 nm are filtered out so that only wavelengths above λ=590 nm are observed.
The dark carriers in (c) are those, which have been tagged with fluorescent green reporters in Procedure A in Example 3 and fluorescent, blue reporters in Procedure E in Example 3. The fluorescent green and the fluorescent blue reporters cannot be observed under this excitation, and so the carriers which have been tagged with green and blue, appear dark.
The red carriers in (c) are those, which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent, blue reporters in Procedure E in Example 3. Under higher magnification, the individual red reporters can be observed. The fluorescent blue reporters cannot be observed under this excitation.
Thus, the red carriers in (c) are predominantly yellow in (b) and red/pink in (a), and the dark carriers in (c) are predominantly green in (b) and green/aqua in (a).
Procedure G:
Populations 4 and 5 in DMF are combined. Refer to FIGS. 11( a ), 11 ( b ) and 11 ( c ). A schematic view is shown in FIG. 12 .
In relation to decoding the images shown in FIGS. 11( a ), 11 ( b ) and 11 ( c ), the four differently-tagged carrier species are easily decoded. The four species of carrier are as follows. Carriers tagged with red and blue reporters correspond to the peptide sequence Arginine-Glycine-carrier; carriers tagged with green and blue correspond to the sequence Arginine-Alanine-carrier; carriers tagged with green and yellow/red correspond to the sequence Lysine-Alanine-carrier and carriers tagged with red and yellow/red reporters correspond to the peptide sequence Lysine-Glycine-carrier.
In the top micrograph (a), the sample is excited with light of wavelength (λ=330-385 nm) and emission wavelengths below λ=420 nm are filtered out so that only wavelengths above λ=420 nm are observed.
The red/pink carriers in (a) are those which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent blue reporters in Procedure E in Example 3. Higher magnification allows clearer observation of individual fluorescent red and fluorescent blue reporter beads.
The bright red carriers in (a) are those, which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent yellow/red reporters in Procedure E in Example 3.
The green/aqua carriers in (a) are those, which have been tagged with fluorescent green reporters in Procedure A in Example 3. Extra information is required (e.g. micrographs (b) and (c)] to distinguish between the carriers tagged with both green and blue reporters and the carriers tagged with both green and yellow/red reporters.
In micrograph (b), the sample is excited with blue light (λ=450-480 nm) and emission wavelengths below λ=515 nm are filtered out so that only wavelengths above λ=515 nm are observed.
The predominantly green carriers in (b) are those which have been tagged with fluorescent green reporters in Procedure A in Example 3. Of these predominantly green carriers, there are two different species of carrier; those exhibiting both green and yellow reporters and those exhibiting only green reporters. The former carriers are those that have been tagged with green and yellow/red reporters. The latter carriers are those that have been tagged with green and blue reporters but the blue reporters cannot be observed under this excitation.
The predominantly yellow carriers in (b) are those which have been tagged with fluorescent green reporters in Procedure A in Example 3. Of these predominantly yellow carriers, there are two different species of carrier; those exhibiting both red and yellow reporters and those exhibiting only red reporters. The former carriers are those that have been tagged with green and yellow/red reporters. The latter carriers are those that have been tagged with red and blue reporters but the blue reporters cannot be observed under this excitation.
In the lower micrograph (c), the sample is excited with green light (λ=510-550 nm) and emission wavelengths below λ=590 nm are filtered out so that only wavelengths above λ=590 nm are observed.
The dark carriers in (c) are those which have been tagged with fluorescent green reporters in Procedure A in Example 3 and fluorescent blue reporters in Procedure E in Example 3. The fluorescent green and the fluorescent blue reporters cannot be observed under this excitation, and so the carriers which have been tagged with green and blue, appear dark.
The red carriers in (c) are those which have been tagged with fluorescent red reporters in Procedure A in Example 3 and fluorescent yellow/red or blue reporters in Procedure E in Example 3. Those carriers which were tagged with both red and yellow/red reporters can be distinguished from those which were tagged with both red and blue by referring to micrograph (b).
The darker (less red) carriers in (b) are those which have tagged with fluorescent green reporters in Procedure A in Example 3 and fluorescent yellow/red reporters in Procedure E in Example 3. The fluorescent green reporters cannot be observed under this excitation but the red signal form the combined yellow/red reporters can be observed.
Thus, the red carriers in (c) are predominantly yellow in (b) and red/pink in (a), and the dark carriers in (c) are predominantly green in (b) and green/aqua in (a).
Example 4
Verification of Coding by Mass Spectrometry
Procedure A:
FMOC-L-Glu-p-benzyloxybenzal alcohol resin (WANG resin) (100 mg, 0.61 mmol/g, Auspep) is deprotected by shaking with excess (10 ml) piperidine/DMF (1:1) for 2 minutes. The solvent is removed by vacuum filtration. Fresh piperidine/DMF is added and the resin is shaken for a further 2 minutes. The solvent is removed and the resin is washed with DMF (5×20 ml) and DCM/Methanol (1:1) and dried under nitrogen gas.
Procedure B:
The resin is added to 0.25 ml of red polyelectrolyte coated silica reporters. Refer to Example I for preparation of polyelectrolyte coated silica reporters. The resin is washed with excess DMF (20×20 ml). The solvent and free reporters are removed by vacuum filtration through a glass sinter of pore size 1740 μm. After the final wash, the resin remains in DMF.
Procedure C:
The monomer Fmoc-Glycine-OH (150 mg, 0.5 mmol, Novabiochem) is mixed with N-[1H-(benzotriazol-1-yl)(dimethylamino)methylene]-N-methylmethanaminimum hexafluorophosphate N-oxide (HBTU, 0.5 mmol, 0.5 M, 1 ml) and diisopropylethylamine (DIEA, 0.6 mmol, 120 μl). The activated amino acid is added to the red-tagged beads (100 mg) as prepared in Procedure B and shaken for 10 minutes. The resin is washed with DMF (5×20 ml).
Procedure D:
The resin is deprotected by shaking with excess (10 ml) piperidine/DMF (1:1) for 2 minutes. The solvent is removed by vacuum filtration. Fresh piperidine/DMF is added and the resin is shaken for a further 2 minutes. The piperidine is removed by washing with DMF (5×20 ml).
Procedure E:
The resin is added to 0.25 ml of green polyelectrolyte coated silica reporters. Refer to Example 1 for preparation of polyelectrolyte coated silica reporters. The resin is washed with excess DMF (20×20 ml). The solvent and free reporters are removed by vacuum filtration through a glass sinter of pore size 17-40 μm. After the final wash, the resin remains in DMF.
Procedure F:
The monomer Fmoc-Lysine(Boc)-OH (235 mg, 0.5 mmol, Novabiochem) is mixed with HBTU (0.5 mmol, 0.5 M, 1 ml) and diisopropylethylamine (DIEA, 0.6 mmol, 120 μl). The activated amino acid is added to the resin (100 mg) as prepared in Procedure E and shaken for 10 minutes. The resin is washed with DMF (5×20 ml).
Procedure G:
The resin is deprotected by shaking with excess (10 ml) piperidine/DMF (1:1) for 2 minutes. The solvent is removed by vacuum filtration. Fresh piperidine/DMF is added and the resin is shaken for a further 2 minutes. The piperidine is removed by washing with DMF (5×20 ml).
Procedure H:
The resin is added to 0.25 ml of blue polyelectrolyte coated silica reporters. The resin is washed with excess DMF (20×20 ml). The solvent and free reporters are removed by vacuum filtration through a glass sinter of pore size 17-40 μm. After the final wash, the resin remains in DMF.
Procedure I:
The monomer Fmoc-Alanine-OH (160 mg, 0.5 mmol, Novabiochem) is mixed with HBTU (0.5 mmol, 0.5 M, 1 ml) and diisopropylethylamine (DIEA, 0.6 mmol, 120 μl). The activated amino acid is added to the resin (100 mg) as prepared in Procedure E and shaken for 10 minutes. The resin is washed with DMF (5×20 ml) and DCM/methanol (1:1) (5×20 ml) and dried under nitrogen gas.
Procedure J:
In order to check the nature of the peptide which was synthesized and tagged in the abovementioned Procedures, the peptide was cleaved from the resin and examined by mass spectroscopy. The sample for mass spectroscopy was prepared in the following way:
Five mg of the dried resin from Procedure I was added to a solution of 95% TFA in water (300 ml) and left for one hour. The solution was removed by passing nitrogen gas over the resin. When dry, a 50% acetonitrile in water solution (pH=2, 100 μl) was added to the resin and 10 μl of this solution was used for mass spectroscopy analysis. The mass spectrum is shown in FIG. 16 . The largest peak is at 626.1 which corresponds to the molecular weight of Fmoc-Alanine-Glycine-Lysine-Glycine-OH (SEQ ID NO:1). This is the exact peptide sequence which was synthesized on the carriers in this three-step amino acid coupling and tagging example.
Example 5
It will be appreciated that Examples 1-4 may be repeated with reporter beads having any number of different surface coatings attached to different types of carrier beads. The resulting combination of carrier bead and attached reporter beads is stable in DMF. In this example, it was found that reporter beads selected from the group consisting of silica beads functionalized with —COOH, silica beads functionalized with PEI, silica beads functionalized with PEI and polyacrylic acid, silica beads functionalized with —NH 2 , uncoated silica beads and polystyrene/DVB beads functionalized with sulfate groups were attached to carrier beads selected from Boc and Fmoc protected resins, aminomethylated resin, polystyrene/polyethylene glycol (TENTAGEL) SOH resin, MBHA resin and protected 4-hydroxymethylphenylacetamidomethyl (PAM) resin.
Example 6
Variations to Attachment Procedures
The number of reporter beads per carrier can be manipulated and relies to some extent on the reporter concentration before carriers are added, reporter bead size, functional groups on the reporter bead and carrier surfaces, and is to a certain extent, time-dependent. Polyelectrolyte coating of the reporters may be used if desired to improve the reporter bead adhesion.
Successful attachment can be achieved by several procedures as described hereinafter.
Procedure A:
Dry carrier beads can be added to a concentrated solution of reporters in solvent as exemplified by the following:—
Aminomethylated resin (100 mg, 0.26 mmol/g, Peptide Institute) is added to 0.25 ml of red polyelectrolyte-coated silica reporters (10 mg/ml) in DMF, prepared as per Example 1.
Procedure B:
Carrier beads are swelled in excess solvent and added to a concentrated solution of reporters in solvent as exemplified by the following:—
Aminomethylated resin (100 mg, 0.26 mmol/g, Peptide Institute) is swelled in DMF and added to 1 ml of red polyelectrolyte-coated silica reporters (10 mg/ml) in DMF, prepared as per Example 1.
Procedure C:
Deprotection and tagging is performed in one step, by mixing the reporter-DMF suspension (as prepared in Example 1) with an equal volume of piperidine and adding to swelled Fmoc-protected carrier beads as shown by the following:—
A. 1 ml suspension of fluorescent red polyelectrolyte-coated reporters in DMF (10 mg/ml, as prepared in Example 1) is shaken with Fmoc-Glycine-resin (100 mg) and 1 ml piperidine for 5 minutes. The solvent is removed and a fresh solution of reporters in piperidine/DMF is shaken with the carriers for another 5 minutes.
Example 7
Washing Procedures
Free reporter beads can be removed from the solvent by vacuum filtration through a glass sinter of pore size 17-40 μl (refer to Procedure B in Example 1) or by other methods such as centrifugation or through the use of magnetic carrier or reporter beads.
Example 8
Effect of Various Organic Solvents and Reaction Conditions on Reporter Bead Adhesion and Exchange
Procedure A:
Examination of reporter exchange in dichloromethane in the presence of excess Pd(PPh 3 ) 4 and diethylazodicarboxylate (DEAD).
Red-tagged carriers (100 mg) and green-tagged carriers (100 mg) are prepared and washed as per Procedure B in Example 3. The red-tagged and the green-tagged carriers are mixed together in DMF and subsequently washed with DCM/methanol then dried under nitrogen gas. 10 mg of the dry carriers is placed into DCM (0.3 ml) with Pd(PPh 3 ) 4 and diethylazodicarboxylate (DEAD). No detectable exchange between red-tagged and green-tagged carriers is observed over a 24 hour period.
Procedure B
The reporter-carrier bead adhesion also survives the following conditions, with no apparent detachment of reporters from the carrier beads and no significant amount of reporter exchange between carriers:—
(i) Red-tagged and green-tagged carrier beads together in organic solvents selected from DMF, THF, DCM, acetonitrile, ethylacetate and methanol. (ii) Red-tagged and green-tagged resin beads together in organic solvents selected from DMF, THF, acetronitrile, ethylacetate and methanol and heated to 50° C. for 45 minutes. (iii) Red-tagged and green-tagged resin beads together in organic solvents selected from DMF and diisopropyl ethylamine (DIEA), THF-NaH (some resin beads break up within 2 hours, most still intact with reporters after 20 hrs), and methanol-NaOCH 3 in the presence of base; (iv) Red-tagged and green-tagged resin beads together in organic solvents selected from DMF and diisopropyl ethylamine (DIEA) and methanol-NaOCH 3 in the presence of base and heated to 50° C. for 45 minutes; (v) Red-tagged and green-tagged resin beads together in organic solvents selected from DCM-TFA (4:1) and DCM-acetic acid in the presence of acid; (vi) Red-tagged and green-tagged resin beads together in organic solvents comprising methanol containing sodium cyanoborohydride and DCM containing Pd(PPh 3 ) 4 ; (vii) Red-tagged and green-tagged resin beads together in organic solvents with reducing agents selected from DCM-pyridine dichromate (resin tends to break up, but reporters are still attached), DMF-5-nitro-2-hydroxy benzaldehyde and DCM-Pd(PPh 3 ) 4 -diethylazo-dicarboxylate (DEAD); and (viii) Red-tagged and green-tagged resin beads together in DMF with peptide coupling reagents comprising FMOC-Gly-OH, HBTU and DIEA.
Procedure C:
Procedure A of Example 3 was repeated with the exception that DMF was replaced by various solvents selected from water, methanol, DCM, acetic acid, water/DMF (4:1) piperidine/DMF (1:1) and methanol/DCM (1:1). Similar results were obtained.
Example 9
Gamma Irradiation of Polyelectrolyte Coated Reporter Beads
In this Example, the polyelectrolyte coated reporter beads were prepared by allowing PEI, then PAA, to adsorb onto the silica beads. These reporter beads showed excellent attachment to various types of carriers. The attachment could be further improved by creation of a larger mesh on the surface of the reporter. This can be achieved by γ-irradiation of the polyelectrolyte coated reporters in a polyelectrolyte solution during the coating procedure. Formation of radicals along the polyelectrolyte chains under gamma irradiation allows cross-linking to occur. This creates a large mesh around the reporter, which enhances the strength of attachment to the carriers by allowing better bridging flocculation. This is exemplified by the following procedure:—
Fluorescent red silica microspheres (10 mg, 1 μm diameter, Microcaps, GmbH) are added to an aqueous solution of PEI (3 ml, 1.2% by weight, MWt. 10000 g/mol, Polysciences Inc.) and sonicated for 30 minutes. The reporter solution is equilibrated for 24 hours to allow adsorption of PEI onto the reporters. The reporters are washed in RO water (MILLI-Q) to remove PEI (5×3 ml) and are resuspended in an aqueous solution of PAA (3 ml, 0.75%, M. Wt.=250000 g/mol, Sigma-Aldrich). Nitrogen gas is bubbled through the solution for 30 minutes to remove oxygen which can act as a scavenger for the radicals formed under gamma irradiation. The solution is then placed in the gamma cell for 1.5 hours at a dose rate of 8 kG/hour (i.e., total dose 11.5-12 kG). The reporters are washed in RO water (MILLI-Q) (5×3 ml) and DMF (5×3 ml) and are left in 1 ml DMF (final reporter concentration=10 mg/ml).
Example 10
Covalent Bonding to Reinforce Reporter-Carrier Attachment
Once reporter bead attachment to carriers has been induced through manipulation of colloidal forces, the robustness of attachment may be strengthened through the formation of supplementary covalent bonds between surface groups of the two colloids. For example, a peptide bond can be formed between deprotected NH 2 on the surface of a carrier and COOH groups on the surface of the reporters (in the presence of coupling agent HBTU and base DIEA). Alternatively, a similar covalent reaction can be induced after attachment of particles by bridging floculation. For example, the reporters may be coated with PAA mesh, floculated and reacted to a carrier bead containing NH 2 -surface groups.
Example 11
Dendrimers
The presence of a mesh of dendritic macromolecules on a carrier bead, reporter bead, or both may enhance the permanent attachment of reporter beads to the carrier. Dendritic macromolecules (dendrimers) are a new class of material (Tsukruk et al., 1997, Langmuir 13 2171) and have a cascade, branched architecture. Manipulation of the macromolecule properties of dendrimers can be achieved by systematic structural variation of the “core” and “branching units” (monomers). The surface porosity, the size and location of specific cavities in the dendritic structure and the final shape of the dendrimer will be affected by these variations.
Example of Tagging Dendrimers with Reporters
Polyamidoamine dendrimers in DMF (0.25 ml, 200 mg/ml, Generation 10, Dendritech) are mixed with red reporters (1 μm diameter, 0.25 ml, 10 mg/ml, Microcaps GmbH) which have been coated with polyelectrolyte (refer to Example 2). After tagging, free reporters are removed by washing with DMF (20×20 ml) and vacuum filtration through a glass sinter. | An assembly of a carrier having one or more reporter beads non-covalently attached thereto which may be used in relation to oligomer libraries. The oligomer libraries may be formed by a combinatorial split-process-recombine procedure. The oligomer library comprises a plurality of molecules comprising a multiplicity of different chemical groups. Each reporter bead has a different marker associated therewith to identify the chemical group attached to the carrier as well as to identify the position in sequence of the chemical group relative to other chemical groups in each molecule of the library. The markers are selected from fluorophores, chromophores, bar codes or radioactive or luminescent labels. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. Pat. application Ser. No. 351,070, filed Apr. 13, 1973, now abandoned.
SUMMARY OF THE INVENTION
This invention concerns 1-arylthio-1,1-dihalomethanesulfonamides and the corresponding sulfinyl and sulfonyl derivatives corresponding to the formula ##SPC2##
Wherein R represents hydrogen, lower alkyl, lower alkoxy or halo, x represents an integer from 0 to 2, n represents an integer from 0 to 3, Y represents halo and R 1 and R 2 independently represent hydrogen, lower alkyl, phenyl or substituted-phenyl, or, together with the nitrogen atom, form a heterocyclic ring also containing up to one oxygen atom in the heterocycle.
In the specification and claims, "lower alkyl" and "lower alkoxy" represent 1, to 2, to 3, to 4, carbon atom straight chain alkyl groups, such as, for example, methyl, ethyl, n-propyl or n-butyl, or a corresponding alkoxy group, respectively; the term "halo" with reference to R represents fluoro, chloro or bromo and with reference to Y represents chloro or bromo; and the term "substituted-phenyl" represents phenyl having lower alkyl, lower alkoxy, chloro or bromo substitution.
The compounds are useful as antimicrobial agents.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The compounds are prepared in the following several ways. To prepare a 1-arylthio-1,1-dihalomethanesulfonamide, a 1-(arylthio)methanesulfonamide is reacted with chlorine or bromine. The reaction is advantageously carried out in the presence of an appropriate organic solvent, i.e., methylene chloride or carbon tetrachloride as reaction medium. The reaction is carried out at a temperature at which hydrogen halide product of reaction is formed, advantageously at a temperature between about 20°C. and 40°C. The reaction consumes equimolar proportions of the starting materials and such proportions or a small excess of halogen are advantageously used. The reaction is carried out in the presence of pyridine as acid acceptor for the by-product hydrogen halide.
In carrying out the reaction, a solution of halogen in an inert organic solvent such as, for example, carbon tetrachloride, is added to the 1-arylthio-methanesulfonamide and the acid acceptor in an inert solvent, advantageously substantially equimolar proportions of the primary reactants, and the reaction mixture is stirred until the reaction is substantially complete. The progress of the reaction can be monitored by examining the nuclear magnetic resonance spectrum of the reaction mixture. The dihalomethanesulfonamide product in solution in the reaction medium is separated from by-product pyridine hydrohalide salt, the filtrate cooled and the dihalomethanesulfonamide product crystallized therefrom. If necessary, it is recrystallized from an appropriate solvent such as methanol, ethanol or the like.
The corresponding 1-(arylsulfinyl)methanesulfonamide or 1-(arysulfonyl)methanesulfonamide is halogenated with substantially two molar proportions of alkali metal hypohalite, advantageously formed in situ from halogen and aqueous alkali metal hydroxide. Such reaction is advantageously carried out by slurrying the 1-(arylsulfinyl)-or 1-(arylsulfonyl)methanesulfonamide in aqueous alkali metal hydroxide and adding thereto bromine or chlorine, advantageously with stirring and cooling and an ice bath to control the exotherm, then maintaining the reaction until halogenation is substantially complete. It is sometimes advantageous to have dioxane present as co-solvent. The solid product is filtered off and recrystallized, advantageously from methanol or ethanol, to give the corresponding arylsulfinyl-or arylsulfonyl-dihalomethanesulfonamide product.
The following examples additionally describe representative specific embodiments and the best modes contemplated by the inventors of carrying out the invention. Temperature is given in Centigrade degrees. The compounds are identified by elemental analysis and by nuclear magnetic resonance spectroscopy.
EXAMPLE 1
1,1-Dibromo-N,N-dimethyl-1-(phenylthio)methanesulfonamide
To a solution of 1.0 g. (4.32 mmol) of N,N-dimethyl-1-(phenylthio)methanesulfonamide and 1.683 g. of dry pyridine in 15 ml. of carbon tetrachloride was added a solution of 3.38 g. (21.2 mmol) of bromine in 15 ml. of carbon tetrachloride. After stirring for 19 hours, a yield of 80% of the titular product was obtained; m.p. 128°-129°C.
Anal. Calcd. for C 9 H 11 Br 2 NO 2 S 2 : C, 27.78; H, 2.85; Br, 41.07; N, 3.60; S, 16.48 Found: C, 27.52; H, 2.81; Br, 40.6 ± 0.2; N, 3.65; S, 16.52.
EXAMPLE 2
1,1-Dibromo-N,N-dimethyl-1-(phenylsulfinyl)-methanesulfonamide
A slurry of 16.1 g. (65 mmol) of crude N,N-dimethyl-1-(phenylsulfinyl)methanesulfonamide (containing ca. 30% N,N-dimethyl-1-(phenylthio)methanesulfonamide as an impurity) in a solution of 8.0 g. (0.20 mol) of sodium hydroxide in 200 ml. of water was stirred and cooled in an ice bath. To this slurry, 32.0 g. (0.2 mol) of bromine was added and stirring continued for 18 hours. The solid which precipitated was filtered off, washed with water, and recrystallized from ethanol to give 13.5 g. (77% yield based on N,N-dimethyl-1-(phenylsulfinyl)methanesulfonamide) of the title compound as white platelets, m.p. 142°-143°C. (dec).
Anal. Calcd. for C 9 H 11 Br 2 NO 3 S 2 : C, 26.68; H, 2.74; Br, 39.45; N, 3.46; S, 15.83. Found: C, 26.3.; H, 2.59; Br, 40.9 ± 0.2; N, 3.5; S, 15.43.
EXAMPLE 3
1,1-Dibromo-N,N-dimethyl-1-(phenylsulfonyl)-methanesulfonamide
A 150 ml. portion of a solution of 11 g. of sodium hydroxide in 250 ml. of water was added to 8.0 g. (0.304 mol) of N,N-dimethyl-1-(phenylsulfonyl)methtanesulfonamide. To the remainder of the sodium hydroxide solution was added 14.0 g. of bromide and this was added dropwise to the sulfone with stirring. The dibromosulfone product was filtered off after 30 minutes and recrystallized from ethanol to give 12.0 g. (84% yield) of product as white crystals; m.p. 144°-145°C.
Anal. Calcd. for C 9 H 11 Br 2 NO 4 S 2 : C, 25.67; H, 2.63; S, 15.23; N, 3.33; Br, 37.95. Found: C, 26.12, 26.03; H, 2.73, 2.60; S, 15.19, 15.12; N, 3.68, 3.78.
EXAMPLE 4
1,1-Dibromo-1-((p-bromophenyl)sulfonyl)methanesulfonamide
A solution of 1.71 g. (6.06 mmol) of 1-((4-bromophenyl)thio)methanesulfonamide, 2 ml. of 30% aqueous hydrogen peroxide and 6 ml. of glacial acetic acid was heated to reflux for one hour and poured on ice. Filtration of the product gave 1.31 g. of crude sulfone (m.p. 162°-165°C.). This was dissolved in 50 ml. of aqueous 1% sodium hydroxide at 5°C. and 2 g. of bromine added. A tacky precipitate formed which solidified on trituration with chloroform and was recrystallized from CHCl 3 /CH 3 OH/hexane to give 0.82 g. of white crystals; m.p. 192°C.
Anal. Calcd. for C 7 H 6 Br 3 NO 4 S 2 : Br, 50.79 Found: Br, 51.1 ± 0.8.
EXAMPLE 5
1,1-Dichloro-((p-methoxyphenyl)sulfonyl)-N,N-dimethylmethanesulfonamide
A 15 ml. portion of aqueous 5% sodium hypochlorite solution was added to a solution of 0.5 g. (1.7 mmol) of 1-((p-methoxyphenyl)sulfonyl)-N,N-dimethylmethanesulfonamide in 50 ml. of dioxane. After one hour, the reaction mixture was acidified with hydrochloric acid, and the dioxane removed in vacuo, leaving a white solid. The solid was slurried with water, filtered off, and recrystallized from absolute ethanol to give 0.37 g. of the title compound as white crystals, m.p. 145°-147°C.
Anal. Calcd. for C 10 H 13 Cl 2 NO 5 S 2 : C, 33.15; H, 3.62; Cl, 19.58; N, 3.86; S, 17.70. Found: C, 33.20; H, 3.50; Cl, 19.70; N, 4.00; S, 17.90.
EXAMPLE 6
1-(Arylsulfonyl)-1,1-dichloromethanesulfonamides
Pursuant to the procedure of Example 5, the following compounds were prepared:
TABLE I__________________________________________________________________________1-(Arylsulfonyl)-1,1-dichloromethanesulfonamides Analyses Calcd. Found R.sub.n NR.sub.1 R.sub.2 m.p.,°C. C H Cl N S C H Cl N S__________________________________________________________________________a) 4-CH.sub.3 NH.sub.2 181-183 30.20 2.85 22.28 4.40 20.15 30.40 2.80 22.30 4.43 20.20b) 4-Cl 163-165 32.32 2.96 26.03 3.43 15.69 32.30 2.99 25.90 3.52 15.90c) H 185-187 48.21 4.27 15.82 3.12 14.30 47.80 4.43 * 3.44 14.20d) 3,4-Cl.sub.2 NH.sub.2 125-128 22.54 1.35 38.03 3.75 17.17 22.50 1.46 38.00 3.72 17.20e) 2,4,5-Cl.sub.3 NH.sub.2 170-172 20.63 0.99 43.50 3.44 15.74 20.90 0.99 * 3.40 15.90__________________________________________________________________________ *Not determined
The compounds of the invention are employed as antimicrobials for the control of bacteria, fungi and yeasts. For such uses, the compounds can be employed in an unmodified form or dispersed on a finely divided solid and employed as dusts. Such mixtures can also be dispersed in water with the aid of a surface-active agent and the resulting emulsions employed as sprays. In other procedures, the products can be employed as active constituents in solvent solutions, oil-in-water or water-in-oil emulsions. The augmented compositions are adapted to be formulated as concentrates and subsequently diluted with additional liquid or solid adjuvants to produce the ultimate treating compositions. Good results are obtained when employing compositions containing antimicrobial concentrations and usually from about 25 to 10,000 parts by weight of one or more of the compounds per million parts of such compositions.
In representative operations, compounds of the present invention were tested for their activity as antimicrobials using conventional agar dilution tests. The following Table presents results, expressed as percent growth inhibition (numerator) over concentration of toxicant in parts per million (denominator).
TABLE II__________________________________________________________________________ExampleSa Ca Ec Pa St Mp Tm Bs Cp Aa Pp At Rn__________________________________________________________________________1 50 100 100 50 100 100100 100 500 500 500 5002 100 100 100 100 100 100 100 100 100 100 100 100 100100 100 100 100 100 100 100 100 100 100 100 100 1003 100 100 100 100 100 100 100 100 100 100 100 100 100500 100 100 100 100 100 100 100 100 100 100 100 1004 100 100 100 100 100 100 100 100 100 100 100 100 100500 500 500 500 500 500 100 100 500 500 100 500 5006a 100 50 100 100 100 50500 500 100 500 100 5006b 100 100 100 50 10 10 10 1006c 50 5006d 100 100 50 100 100 100 50 100100 500 500 10 100 10 500 1006e 100 100 50 100 100 100 100 100100 500 500 10 10 10 500 100__________________________________________________________________________Sa = S. aureus Ca = C. albicans Ec = E. coli Pa = P. aeruginosaSt = S. typhosa Mp = M. phlei Tm = T. mentagrophytesBs = B. subtilis Cp = C. pelliculosa Aa = A. aerogenes Pp = P. pullulansAt = A. terreus Rn = R. nigricans
The process for making the starting materials herein which are 1-(arylsulfinyl)methanesulfonamides and 1-(arylsulfonyl)methanesulfonamides, is described in U.S. Pat. No. 3,862,184, filed Mar. 5, 1973. The process for making 1-(arylthio)methanesulfonamides is described in our copending U.S. Pat. application Ser. No. 314,793, filed Dec. 13, 1972. | The compounds of the formula ##SPC1##
In which R is lower alkyl, lower alkoxy or halo, x is an integer from 0 to 2, n is an integer from 0 to 3, Y is halo and R 1 and R 2 independently are hydrogen, lower alkyl, phenyl or substituted phenyl, or, together with the nitrogen atom, form a heterocyclic ring also containing up to one oxygen atom in the heterocycle. The compounds in which x is 0 are prepared by adding chlorine or bromine to a 1-arylthiomethanesulfonamide in the presence of pyridine to form the 1-arylthio-1, 1-dihalomethanesulfonamide. The compounds in which x is 1 or 2 is prepared by adding sodium hypochlorite or sodium hypobromite to a 1-(arylsulfinyl)methane-sulfonamide or a 1-(arylsulfonyl)methanesulfonamide to form the 1-(arylsulfinyl)-1,1-dihalomethanesulfonamide or 1-(arylsulfonyl)-1,1-dihalomethanesulfonamide, respectively. The compounds are useful as antimicrobial agents. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This is a divisional of U.S. Ser. No. 11/617,317 now U.S. Pat. No. 7,520,323, filed Dec. 28, 2006 herein incorporated by reference, which is a divisional of U.S. Ser. No. 10/076,993, filed Feb. 15, 2002, now U.S. Pat. No. 7,383,882, which is a continuation-in-part of U.S. Ser. No. 09/997,021, filed Nov. 28, 2001, now U.S. Pat. No. 6,938,689, which is a continuation-in-part of U.S. Ser. No. 09/179,507, filed Oct. 27, 1998, now U.S. Pat. No. 6,283,227.
TECHNICAL FIELD
The invention relates generally to interactive and/or secure activation of tools, such as tools used in well, mining, and seismic applications.
BACKGROUND
Many different types of operations can be performed in a wellbore. Examples of such operations include firing guns to create perforations, setting packers, opening and closing valves, collecting measurements made by sensors, and so forth. In a typical well operation, a tool is run into a wellbore to a desired depth, with the tool being activated thereafter by some mechanism, e.g., hydraulic pressure activation, electrical activation, mechanical activation, and so forth.
In some cases, activation of downhole tools creates safety concerns. This is especially true for tools that include explosive devices, such as perforating tools. To avoid accidental detonation of explosive devices in such tools, the tools are typically transferred to the well site in an unarmed condition, with the arming performed at the well site. Also, there are safety precautions taken at the well site to ensure that the explosive devices are not detonated prematurely. Another safety concern that exists at a well site is the use of wireless, especially radio frequency (RF), devices, which may inadvertently activate certain types of explosive devices. As a result, such wireless devices are usually not allowed at a well site, thereby limiting communications options that are available to well operators. Yet another concern associated with using explosive devices at a well site is the presence of stray voltages that may inadvertently detonate the explosive devices.
A further safety concern with explosive tools is that they may fall into the wrong hands. Such explosive tools pose great danger to persons who do not know how to handle explosive tools, or who want to use the explosive tools to harm others.
In addition to well applications, other applications that involve the use of explosive tools include mining applications and seismic applications. Similar types of safety concerns exist with such other types of explosive tools. Thus, a need continues exist to enhance the safety associated with the use of explosive tools as well as with other types of tools. Also, a need continues to exist to enhance the flexibility of controlling the operation of such explosive tools.
SUMMARY OF THE INVENTION
In general, an improved method and apparatus is provided to enhance the safety and flexibility associated with use of a tool. For example, a method of activating a tool includes checking an authorization code of a user to verify that the user has access to activate the tool. In addition, data pertaining to an environment around the tool is received. Activation of the tool is enabled in response to the authorization code and the data indicating that the environment around the tool meets predetermined one or more criteria for activation of the tool.
Other or alternative features will become apparent from the following description, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is block diagram of an example arrangement of control systems, sensors, and a downhole well tool.
FIG. 2 is a block diagram of a perforating tool, according to one embodiment, that can be used in the system of FIG. 1 .
FIGS. 3A-3B are a flow diagram of a process performed by a surface unit in accordance with an embodiment.
FIGS. 4 and 5 illustrate processes for secure and interactive activation of a perforating tool.
FIG. 6 is a block diagram of an example test arrangement including a tester box coupled to a tool under test, and a user interface device to control the tester box.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and downwardly”; “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.
Referring to FIG. 1 , a system according to one embodiment includes a surface unit 100 that is coupled by cable 102 (e.g., a wireline) to a tool 104 . In the example shown in FIG. 1 , the tool 104 is a tool for use in a well. For example, the tool 104 can include a perforating tool or other tool containing explosive devices, such as pipe cutters and the like. In other embodiments, other types of tools can be used for performing other types of operations in a well. For example, such other types of tools include tools for setting packers, opening or closing valves, logging, taking measurements, core sampling, and so forth. In the embodiments described below, safety issues associated with well tools containing explosive devices are discussed. However, similar methods and apparatus can be applied to tools having explosive devices in other applications, e.g., mining, seismic acquisition, surface demolition, armaments, and so forth.
The tool 104 includes a safety sub 106 and a plurality of guns 108 . In one embodiment, the safety sub 106 differs from the gun 108 in that the safety sub 106 does not include explosive devices that are present in the guns 108 . The safety sub 106 serves one of several purposes, including providing a quick connection of the tool 104 to the cable 102 . Additionally, the safety sub 106 allows electronic arming of the perforating tool 104 downhole instead of at the surface. Because the safety sub 106 does not include explosive devices, it provides electrical isolation between the cable 102 and the guns 108 so that electrical activation of the guns 108 is disabled until the safety sub 106 has been activated to close an electrical connection.
In the example of FIG. 1 , the cable 102 is run through a winch assembly 110 , which is coupled to a depth sensor 112 . The depth sensor 112 monitors the rotation of the winch assembly 110 to determine the depth of the perforating tool 104 . The data relating to the depth of the tool 104 is communicated to the surface unit 100 .
In some systems, an internal (hardware or software) drive system can be used to simulate that the tool 104 has descended to a certain depth in the wellbore, even though the tool 104 is still at the earth surface. The depth sensor 112 can be used by the surface unit to verify that the tool 104 has indeed been lowered into the wellbore to a target depth. As a safety precaution, the ability to use the output of the internal hardware or drive system to enable activation of the tool 104 is prohibited.
The perforating tool 104 also includes a number of sensors, such as sensors 114 in the safety sub and sensors 116 in the guns 108 . Although FIG. 1 shows each gun 108 as containing sensors 116 , less than all of the guns can be selected to include sensors in other embodiments.
Data from the sensors 114 and 116 are communicated over the cable 102 to a logging module 120 in the surface unit 100 . The logging module 120 is capable of performing bi-directional communications with the sensors 114 and 116 over the cable 102 . For example, the logging module 120 is able to issue commands to the sensors 114 and 116 to take measurements, and the logging module 120 is then able to receive measurement data from the sensors 114 and 116 . Data collected by the logging module 120 is stored in a storage 122 in the surface unit 100 . Examples of the storage 122 include magnetic media (e.g., a hard disk drive), optical media (e.g., a compact disk or digital versatile disk), semiconductor memories, and so forth. The surface unit 100 also includes activation software 124 that is executable on a processor 126 . The activation software 124 is responsible for managing the activation of the perforating tool 104 in response to user commands. The user commands can be issued from a number of sources, such as directly through a user interface 128 at the surface unit 100 , from a remote site system 130 over a communications link 132 , or from a portable user interface device 134 over a communications link 136 .
In one embodiment, the communications links 132 and 136 include wireless links, in the form of radio frequency (RF) links, infrared (IR) links, and the like. Alternatively, the communications links 132 and 136 are wired links. The surface unit 100 includes a communications interface 138 for communicating with the user interface device 134 and the remote site system 130 over the respective links. The remote site system 130 also includes a communications interface 140 for communicating over the communications link 132 to the surface unit 100 . Also, the remote site system 130 includes a display 142 for presenting information (e.g., status information, logging information, etc.) associated with the surface unit 100 .
The user interface device 134 also includes a communications interface 144 for communicating over the communications link 136 with the surface unit 100 . Additionally, the user interface device 134 includes a display 146 to enable the user to view information associated with the surface unit 100 . An example of the user interface device 134 is a personal digital assistant (PDA), such as a PALM® device, a WINDOWS® CE device, or other like device. Alternatively, the user interface device 134 includes a laptop or notebook computer.
In accordance with an embodiment, a security feature of the surface unit 100 is a smart card interface 148 for interacting with a smart card of a user. The smart card interface 148 is capable of reading identification information of the user (e.g., a digital signature, a user code, an employee number, and so forth). The activation software 124 uses this identification information to determine if the user is authorized to access the surface unit 100 and to perform activation of the perforating tool 104 . The identification information is part of the “authorization code” provided by a user to gain access to the surface unit 100 .
A smart card is basically a card with an embedded processor and storage, with the storage containing various types of information associated with a user. Such information includes a digital signature, a user profile, and so forth.
In an alternative embodiment, instead of a smart card interface 148 , the surface unit 100 can include another type of security feature, such as providing a prompt in which a user has to enter his or her user name and password. In yet another embodiment, the security mechanism of the surface unit 100 includes a biometric device to scan a biometric feature (e.g., fingerprint) of the user. The user interface device 134 can similarly include a smart card reader or biometric input device.
Alternatively, the user enters information and commands using either the user interface device 134 or the remote site system 130 . The user interface device 134 may itself store an authorization code, such as in the form of a user code, digital signature, and the like, that is communicated to the surface unit 100 with any commands issued by the user interface device 134 . Only authorized user interface devices 134 are able to issue commands that are acted on by the surface unit 100 . Although not shown, the user interface device 134 can optionally include a smart card interface to interact with the smart card of the user.
In the example shown, the remote site system 130 also includes a smart card interface 150 . Thus, before a user is able to issue commands from the remote site system 130 to the surface unit 100 to perform various actions, the user must be in possession of a smart card that enables access to the various features provided by the surface unit 100 .
In this way, the surface unit 100 cannot be accessed by unauthorized users. Therefore, safety problems associated with the unauthorized use of the perforating tool 104 is avoided.
Another safety feature offered by the perforating tool 104 is that each of the guns 108 is associated with a unique code or identifier. This code or identifier must be issued by the surface unit 100 with an activate command for the gun 108 to be activated. If the code or identifier is not provided, then the gun 108 cannot be fired. Thus, if the perforating tool 104 is stolen or is lost, unauthorized users will not be able to activate the guns 108 since they do not know what the codes or identifiers are. The safety sub 106 is also associated with a unique code or identifier that must be received by the safety sub 106 for the safety sub 106 to be activated to electrically arm the perforating tool 104 .
Another feature allowed by using unique codes or identifiers for the guns 108 is that the guns can be traced (to enable the tracking of lost or misplaced guns). Also, the unique codes or identifiers enable inventory control, allowing a well operator to know the equipment available for well operations.
Yet another safety feature associated with the guns 108 according to one embodiment is that they use exploding foil initiators (EFIs), which are safe in an environment in which wireless signals, such as RF signals, are present. As a result, this feature of the guns 108 enables the use of RF communications between the surface unit 100 and the remote site system 130 and with the user interface device 134 . However, in other embodiments, conventional detonators can be used in the perforating tool 104 , with precautions taken to avoid use of RF signals. The EFI detonator is one example of an electro-explosive device (EED) detonator, with other examples including an exploding bridge wire (EBW) detonator, semiconductor bridge detonator, hot-wire detonator, and so forth.
Another feature offered by the surface unit 100 according to some embodiments is the ability to perform “interactive” activation of the perforating tool 104 . The “interactive” activation feature refers to the ability to communicate with the sensors 114 and/or 116 in the perforating tool 104 before, during, and after activation of the perforating tool 104 . For example, the sensors 114 and/or 116 are able to take pressure measurements (to determine if an under balance or over balance condition exists prior to perforating), take temperature measurements (to verify explosive temperature ratings are not exceeded), and take fluid density measurements (to differentiate between liquid and gas in the wellbore). Also, the surface unit 100 is able to interact with the depth sensor 112 to determine the depth of the perforating tool 104 . This is to ensure that the perforating tool 104 is not activated prior to it being at a safe depth in the wellbore. As an added safety precaution, a user will be prevented from artificially setting the depth of the perforating tool below a predetermined depth for test purposes. In some systems, such a depth can be set by software or hardware to simulate the tool being in the wellbore. However, due to safety concerns, artificially setting the depth to a value where a gun is allowed to be activated is prohibited.
The sensors 114 and/or 116 may also include voltage meters to measure the voltage of the cable 102 at the upper head of the perforating tool 104 , the voltages at the detonating devices in the respective guns 108 , the amount of current present in the cable 102 , the impedance of the cable 102 and other electrical characteristics. The sensors may also include accelerometers for detecting tool movement as well as shot indication. Shot indication can be determined from waveforms provided by accelerometers over the cable 102 to the surface unit 100 . Alternatively, the waveform of the discharge voltage on the cable 102 can be monitored to determine if a shot has occurred.
The sensors 114 and/or 116 may also include moisture detectors to detect if excessive moisture exists in each of the guns 108 . Excessive moisture can indicate that the gun may be flooded and thus may not fire properly or at all.
The sensors may also include a position or orientation sensor to detect the position or orientation of a gun in well, to provide an indication of well deviation, and to detect correct positioning (e.g., low side of casing) before firing the gun. Also, the sensors may include a strain-gauge bridge sensor to detect external strain on the perforating tool 104 that may be due to pulling or other type of strain on the housing or cable head of a gun that is stuck in the well. Other types of sensors include acoustic sensors (e.g., a microphone), and other types of pressure gauges.
Other types of example sensors include equipment sensors (e.g., vibration sensors), sand detection sensors, water detection sensors, scale detectors, viscosity sensors, density sensors, bubble point sensors, composition sensors, infrared sensors, gamma ray detectors, H 2 S detectors, CO 2 detectors, casing collar locators, and so forth.
One of the aspects of the sensors 116 is that they are destroyed with firing of the guns 108 . However, the sensors 114 in the safety sub 106 may be able to survive detonation of the guns 108 . Thus, these sensors 114 can be used to monitor well conditions (e.g., measure pressure, temperature, and so forth) before, during, and after a perforating operation.
In addition to the sensors that are present in the perforating tool 104 , other sensors 152 can also be located at the earth surface. The sensors 152 are able to detect shock or vibrations created in the earth due to activation of the perforating tool 104 . For example, the sensors 152 may include geophones. The sensors 152 are coupled by a communications link 154 , which may be a wireless link or a wired link, to the surface unit 100 . Data from the sensors 152 to the surface unit 100 provide an indication of whether the perforating tool 104 has been activated.
The safety sub 106 and guns 108 of the perforating tool 104 are shown in greater detail in FIG. 2 . In the example shown in FIG. 2 , the safety sub 106 includes a control unit 14 A, and the guns 108 include control units 14 B, 14 C. Although only two guns 108 are shown in the example FIG. 2 , other embodiments may include additional guns 108 . Each control unit 14 is coupled to switches 16 and 18 (illustrated at 16 A- 16 C and 18 A- 18 C). The switches 18 A- 18 C are cable switches that are controllable by the control units 14 A- 14 C, respectively, between on and off positions to enable or disable current flow through portions of the cable 102 . When the switch 18 is off, then the portion of the cable 102 below the switch 18 is isolated from the portion of the cable 102 above the switch 18 . The switches 16 A- 16 C are detonating switches.
In the safety sub 106 , the detonating switch 16 A is not connected to a detonating device. However, in the guns 108 , the detonating switches 16 B, 16 C are connected to detonating devices 22 B, 22 C, respectively. If activated to an on position, a detonating switch 16 allows electrical current to flow to a coupled detonating device 22 to activate the detonating device. The detonating device 22 B, 22 C includes an EFI detonator or other detonators. The detonating devices 22 B, 22 C are ballistically coupled to explosives, such as shaped charges or other explosives, to perform perforating.
As noted above, the safety sub 106 provides a convenient mechanism for connecting the perforating tool 104 to the cable 102 . This is because the safety sub 106 does not include a detonating device 22 or any other explosive, and thus does not pose a safety hazard. The switch 18 A of the safety sub 106 is initially in the open position, so that all guns of the perforating tool 104 are electrically isolated from the cable 102 by the safety sub 106 . Because of this feature, electrically arming of the perforating tool 104 does not occur until the perforating tool 104 is positioned downhole and the switch 18 A is closed.
Another feature allowed by the safety sub 106 is that the guns 108 can be pre-armed (by connecting each detonating device 22 in the gun 108 ) during transport or other handling of the perforating tool 104 . Thus, even though the perforating tool 104 is transported ballistically armed, the open switch 18 A of the safety sub 106 electrically isolates the guns 108 from any activation signal during transport or other handling.
FIGS. 3A-3B are a flow diagram of a tool activation process, which is performed by the activation software 124 according to one embodiment. Before access is provided for activating the perforating tool 104 , the activation software 124 checks (at 202 ) if an authorization code has been received. The authorization code includes a digital signature, a user code, a user name and password, or some other code. The authorization code can be stored on a smart card and communicated to the surface unit 100 through the smart card interface 148 . Alternatively, the authorization code can be manually entered by the user through a user interface.
If an authorization code has been received and verified, the activation software 124 determines (at 204 ) the level of access provided to the user. Users are assigned a hierarchy of usage levels, with some users provided with a higher level of access while others are provided with a lower level of access. For example, a user with a higher level of access is authorized to activate the perforating tool to fire guns. A user with a lower access level may be able only to send inquiries to the perforating tool to determine the configuration of the perforating tool, and possibly, to perform a test of the perforating tool (without activating the detonating devices 22 in the perforating tool 104 ).
The activation software 24 also checks (at 206 ) for a depth of the perforating tool 104 in the well. Activation of the perforating tool 104 is prohibited unless the perforating tool 104 is at the correct depth. While the perforating tool 104 is not at a correct depth, as determined (at 208 ), further actions are prevented. However, once the perforating tool 104 is at the correct depth, the activation software 124 performs (at 210 ) various interrogations of control units 14 in the perforating tool 100 . Interrogations may include determining the positions of switches 16 and 18 in the perforating tool 104 , the status of the control unit 14 , the configuration and arrangement of the perforating tool 104 (e.g., number of guns, expected identifications or codes of each control unit, etc.), and so forth.
Once the status information has been received from the perforating tool 104 , the activation software 124 compares (at 212 ) the information against an expected configuration of the perforating tool 104 . Based on the interrogations and the comparison performed at 210 and 212 , the activation software 124 determines (at 214 ) if the perforating tool 104 is functioning properly or is in the proper configuration. If not, then the activation process ends with the tool 104 remaining deactivated. However, if the tool is determined to be functioning properly and in the expected configuration, the activation software 124 waits (at 216 ) for receipt of an arm command from the user. The arm command can be provided by the user through the user interface 128 of the surface unit 100 , through the user interface device 134 , or through the remote site system 130 .
Upon receipt of the arm command, the activation software 124 checks (at 218 ) the depth of the perforating tool 104 again. This is to ensure that the perforating tool 104 has not been raised from its initial depth.
Next, the activation software 124 checks (at 220 ) for various downhole environment conditions, including pressure, temperature, the presence of gas or liquid, the deviation of the wellbore, and so forth.
If the proper condition is not present, as determined at 224 , the activation software 124 communicates (at 226 ) an indication to the user, such as through the user interface 128 of the surface unit 100 , the display 146 of the user interface device 134 , or the display 142 of the remote site system 130 . Arming is prohibited.
However, if the condition of the well and the position of the perforating tool 104 is proper, the activation software 124 issues an arm command (at 228 ) to the perforating tool 100 . The arm command is received by the safety sub 106 , which closes the cable switch 18 A in response to the arm command. Optionally, the cable switches 18 B, 18 C can also be actuated closed at this time.
The activation software 124 waits (at 230 ) for receipt of an activate command from the user. Upon receipt of the activate command, the activation software 124 re-checks (at 232 ) the environment conditions and the depth of the penetrating tool. The activation software 124 also checks (at 234 ) the gun position and orientation. It may be desirable to shoot the gun at a predetermined angle with respect to the vertical. Also, the shaped charges of the perforating tool 104 may be oriented to shoot in a particular direction, so the orientation has to be verified.
If the environment condition and gun position is proper, as determined at 236 , the activation software 124 sends (at 238 ) the activate command to the perforating tool 104 . The activate command may be encrypted by the activation software 124 for communication over the cable 102 . The control units 14 in the perforating tool 104 are able to decrypt the encrypted activate command. In one embodiment, the activate command is provided with the proper identifier code of each control unit 14 . Each control unit 14 checks this code to ensure that the proper code has been issued before activating the appropriate switches 16 and 18 to fire the guns 108 in the perforating tool 104 .
In one sequence, the guns 108 of the perforating tool 104 are fired sequentially by a series of activate commands. In another sequence, the activate command is provided simultaneously to all guns 108 , with each gun 108 preprogrammed with a delay that specifies the delay time period between the receipt of the activate command and the firing of the gun 108 . The delays in plural guns 108 may be different.
During and after activation of the perforating tool 104 , measurement data is collected (at 240 ) from the various sensors 114 , 116 , and 152 . The collected measurement data is then communicated (at 242 ) to the user.
FIG. 4 illustrates a flow diagram of a process of performing secure activation of an explosive tool, such as the perforating tool 104 , according to one embodiment. A central management site (not shown) provides (at 302 ) a profile of a user that includes his or her associated identifier, authorization code, personal identification number (PIN) code, digital signature, and access level. This profile is loaded as a certificate (at 304 ) into the surface unit 100 , where it is stored in the storage 122 . During use, a user inserts (at 306 ) his or her smart card into the smart card interface 148 of the surface unit 100 . The surface unit 100 may prompt for a PIN code through the user interface 128 , which is then entered by the user. The surface unit 100 checks (at 308 ) to ensure that a user is authorized to use a system based on the stored certificate and notifies the user of access grant.
Next, the user requests (at 310 ) arming of the perforating tool 104 , which is received by the surface unit 100 . In response, as discussed above, the surface unit 100 checks (at 312 ) the depth of the perforating tool 104 and the data from other sensors from the perforating tool 104 to determine if the perforating tool 104 is safe to arm.
The user then issues a fire command (at 314 ), which is received by the surface unit 100 . The surface unit 100 then checks (at 316 ) that the perforating tool 104 is safe to activate, and if so, sends an encrypted activate command to the perforating tool 104 .
The control unit 14 A in the safety sub 106 stores a private key at manufacture. This private key is used by the control unit 14 A in the safety sub 106 to decrypt the activate command (at 318 ). The decrypted activate command is then forwarded to the guns 108 to fire the guns.
FIG. 5 illustrates a flow diagram of a process of remotely activating the perforating tool 104 . In the context of FIG. 1 , the remote activation is performed by a user at the remote site system 130 . In the example of FIG. 5 , two users are involved in remotely activating the perforating tool 104 , with user 1 at the well site and user 2 at the remote site system 130 . As before, a central management system authorizes user names and their associated information and access levels (at 302 ) and communicates certificates containing the profiles (at 404 ) to the surface unit 100 and to the remote site system 130 for storage.
At the surface unit 100 , user 1 inserts (at 406 ) his or her smart card into the surface unit 100 , along with the user's PIN code, to request remote arming and activation of the perforating tool 104 . This indication is communicated (at 408 ) from the surface unit 100 to the remote site system 130 over the communications link 132 . User 1 also verifies (at 407 ) that all is safe and ready to fire at the surface unit 100 .
User 2 inserts his or her smart card into the smart card interface 150 of the remote site system 130 to gain access to the remote site system 130 . Once authorized, user 2 requests (at 410 ) arming of the perforating tool 104 . The surface unit 100 checks (at 412 ) that user 2 is authorized by accessing the certificate stored in the surface unit 100 . This check can alternatively be performed by the remote site system 130 .
The surface unit 100 then checks (at 414 ) the depth of the perforating tool 104 along with data from other sensors of the perforating tool 104 to ensure that the perforating tool 104 is safe to arm. Once the verification has been performed and communicated back to the remote site system 130 , user 2 issues an activate command (at 416 ) at the remote site system 130 . The surface unit 100 checks (at 418 ) to ensure that the perforating tool 104 is safe to activate, and then sends an encrypted activate command. The encrypted activate command is received by the safety sub 106 , with the encrypted activate command decrypted (at 420 ) by the control unit 14 A in the safety sub 106 .
According to some embodiments of the invention, another feature is the ability to test the perforating tool 104 to ensure the perforating tool 104 is functioning properly. The test can be performed at the well site or at an assembly shop that is remote from the well site. To do so, as shown in FIG. 6 , a tester box 500 is coupled to the perforating tool 104 over a communications link 502 through a communications interface 504 . If the test is performed at the well site, the tester box 500 can be implemented in the surface unit 100 . At the assembly shop or at some other location, the tester box 500 is a stand-alone unit. The tester box 500 includes a communications port 503 that is capable of performing wireless communications with communications port 144 in the user interface device 134 . The communications can be in the form of IR communications, RF communications, or other forms of wireless communications. The communications between the user interface device 134 and the tester box 500 can also be over a wired link.
In one embodiment, various graphical user interface (GUI) elements (e.g., windows, screens, icons, menus, etc.) are provided in the display 146 of the user interface device 134 . The GUI elements include control elements such as menu items or icons that are selectable by a user to perform various acts. The GUI elements also include display boxes or fields in which information pertaining to the perforating tool 104 is displayed to the user.
In response to user selection of various GUI elements, the user interface device 134 sends commands to the tester box 500 to cause a certain task to be performed by control logic in the tester box 500 . Among the actions taken by the tester box 500 is the transmission of signals over the cable 502 to test the components of the perforating tool 104 . Feedback regarding the test is communicated back to the tester box 500 , which in turn communicates data over the wireless medium to the user interface device 134 , where the information is presented in the display 146 . As an added safety feature, the tester box 500 can also include a smart card reader or biometric input device to verify user authorization.
A more detailed description of the tester box 500 and components in the perforating tool 104 to enable this testing feature is discussed in greater detail in U.S. Ser. No. 09/997,021, entitled “Communicating with a Tool,” filed Nov. 28, 2001, now U.S. Pat. No. 6,938,689, which is hereby incorporated by reference.
The various systems and devices discussed herein each includes various software routines or modules. Such software routines or modules are executable on corresponding control units or processors. Each control unit or processor includes a microprocessor, a microcontroller, a processor card (including one or more microprocessors or microcontrollers), or other control or computing devices. As used here, a “controller” refers to a hardware component, software component, or a combination of the two. Although used in the singular sense, a “controller” can also refer to plural hardware components, plural software components, or a combination thereof.
The storage devices referred to in this discussion include one or more machine-readable storage media for storing data and instructions. The storage media include different forms of memory including semiconductor memory devices such as dynamic or static random access memories (DRAMs or SRAMs), erasable and programmable read-only memories (EPROMs), electrically erasable and programmable read-only memories (EEPROMs) and flash memories; magnetic disks such as fixed, floppy and removable disks; other magnetic media including tape; and optical media such as compact disks (CDs) or digital video disks (DVDs). Instructions that make up the various software routines or modules in the various devices or systems are stored in respective storage devices. The instructions when executed by a respective control unit or processor cause the corresponding node or system to perform programmed acts.
The instructions of the software routines or modules are loaded or transported to each device or system in one of many different ways. For example, code segments including instructions stored on floppy disks, CD or DVD media, a hard disk, or transported through a network interface card, modem, or other interface device are loaded into the device or system and executed as corresponding software routines or modules. In the loading or transport process, data signals that are embodied in carrier waves (transmitted over telephone lines, network lines, wireless links, cables, and the like) communicate the code segments, including instructions, to the device or system. Such carrier waves are in the form of electrical, optical, acoustical, electromagnetic, or other types of signals.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention. | A tool activation system and method includes receiving an authorization code of a user to verify access rights of a user to activate the tool. In one example, the authorization code is receive from a smart card. The environment around the tool, which can be in a wellbore, for example, is checked. In response to the authorization code and the checking of the environment, activation of the tool is enabled. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to the removal of cyanide from a fluid using hydrogen peroxide generated by combustion. The invention has particular applicability to the removal of cyanide from waste water generated during mining operations.
Mining operations, including gold mining, and other metal-extraction procedures can produce a large quantity of waste water containing cyanide. Since cyanide-bearing waste is too difficult to transport safely, the cyanide must be removed or detoxified in the vicinity of the mining site. A conventional method for removing cyanide from waste liquids is to oxidize the cyanide using hydrogen peroxide, as disclosed, for example, in U.S. Pat. Nos. 3,970,554 and 4,416,786. Residual amounts of cyanide remaining in a waste liquid thus treated can also be removed by bringing indigenous, cyanidemetabolizing microbes into contact with the waste fluid.
Unfortunately, hydrogen peroxide is not only expensive but also bulky, necessitating large tanks for its storage. Moreover, mining operations are frequently conducted at remote sites, to which transporting hydrogen peroxide is costly. In addition, the effectiveness of cyanide-removing microbes, upon which conventional mining operations heavily rely, is hampered, especially in colder environments, by a paucity of organic material which the microbes can use as carbon sources.
Accordingly, there is a need for more effective methods and systems for removing cyanide from waste fluid, particularly in the context of mining operations.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a system that removes cyanide from waste fluid in an efficient manner.
Another object of the invention is to provide a cyanide-removal system that does not require storage of bulky reagents.
Another object of the present invention is to provide a system for removing cyanide that also yields organic material capable of serving as a carbon source for cyanide-metabolizing microbes.
Yet another object of the present invention is to provide a cyanide-removal system that is practicable for use at remote mining locations.
In accomplishing the foregoing objects, there has been provided, according to one aspect of the present invention, a method for treating a fluid stream, comprising the steps of (a) providing a fluid stream that contains cyanide species and (b) burning a fuel and quenching the burning with the fluid stream to produce hydrogen peroxide, such that at least a portion of the cyanide species are oxidized by the hydrogen peroxide. In a preferred embodiment, the method further comprises a step (c), after step (b), of bringing the fluid stream into contact with microbes that metabolize a cyanide species. In another preferred embodiment, the aforementioned microbes utilize partial oxidation products produced by the burning as a carbon source such that, during step (c), degradation of cyanide species in the fluid stream by the microbes is facilitated.
In accordance with another aspect of the present invention, a system is provided that comprises (a) a fluid stream that contains a cyanide species; (b) apparatus for producing hydrogen peroxide by burning a fuel and quenching the burning with a liquid to produce hydrogen peroxide; and (c) means for introducing the fluid stream into the apparatus such that the fluid stream quenches the burning to produce hydrogen peroxide which oxidizes at least some of the cyanide species in the fluid stream, yielding an effluent. In a preferred embodiment, the apparatus produces partial oxidation products, in addition to hydrogen peroxide, via the burning mentioned above.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is described below with reference to the accompanying drawings in which:
FIG. 1 illustrates a generator which can be used according to the present invention; and
FIG. 2 illustrates a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has been discovered that an aqueous fluid stream which is "cyanide-containing"--that is, a waste stream containing cyanide and related species like cyanate, thiocyanate and cyanogen (collectively "cyanide species")--can be treated to remove cyanide values by using the fluid stream to quench the burning of a fuel. During such a quenching, hydrogen peroxide is generated that oxidizes cyanide and related species present in the fluid stream. The quenching also produce an organic material, in the form of partial combustion products other than hydrogen peroxide, which enters the fluid stream to provide a carbon source for microbes which can be enlisted downstream to metabolize any residual cyanide species not oxidized by the primary hydrogen-peroxide treatment.
Suitable apparatus for conducting a quenching operation within the present invention is disclosed in U.S. Pat. No. 4,540,052 ("'052 patent"), the contents of which are hereby incorporated by reference. The '052 patent describes a generator that employs water as the quench fluid in the context of producing a biocide which contains partial oxidation products, including hydrogen peroxide.
In the present invention, on the other hand, a partial oxidation products which are generated by burning a fuel and then quenching the burning are employed to effect a hydrogen peroxide-based oxidation of cyanide species present in the quenching-fluid (waste) stream. In contrast to the biocidal utility identified in the '052 patent, moreover, the partial oxidation products can optionally be exploited, pursuant to the present invention, to enhance microbial breakdown of residual cyanide.
FIG. 1 depicts the basic structure of a generator 100 suitably used according to the present invention. The generator includes a mixing zone 2, a combustion zone 4, a quench or cooling chamber 6, and a discharge nozzle 8. Fuel is introduced through the fuel introduction pipe 10 as a generally axial stream into mixing zone 2. Air is introduced into the mixing zone 2 through swirl structure 12. The swirl structure 12 is one of several well-known structures, such as an annular ring with fins at appropriate angles, suitable for creating an annular stream of air. The fuel and air are partially mixed in mixing zone 2 and are then passed through a barrier 14. The barrier 14 is a perforated grid, which together with the axial introduction of fuel and the annular introduction of air creates an annularly stratified body of fluids which is fuel rich along the axis of combustion zone 4 and fuel lean adjacent to the walls of combustion zone 4.
The generator of FIG. 1 can be fueled with any conventional gaseous fuel like natural gas. Ignition of the fuel and air mixture is effected by a spark plug 16. Quench fluid is introduced through line 18, passes through annular chamber 20 in indirect heat exchange with the combustion zone, and then enters annular plenum 22. The fluid is finally introduced into the flame front through a plurality of annularly spaced apertures 24.
The combustion occurring in the generator produces partial oxidation products The mix of oxygen-containing oxidation products can be adjusted by controlling the flow rates of fuel, air and quenching fluid. Severe (low oxygen) conditions favor the production of hydrogen peroxide, while milder conditions favor production of alcohols, peroxides, ketones, ethers, esters and acids. Intermediate conditions favor the production of aldehydes. It is preferable that conditions be controlled to maximize the amount of hydrogen peroxide introduced into the quenching, cyanide-containing stream.
By way of illustration, partial oxidation of propane with air in a high intensity combustor of the above-described design, utilizing water as a quench fluid under conditions maximizing the yield of hydrogen peroxide, involves the following reactions: ##STR1## Aside from unreacted propane and air, along with nitrogen, carbon monoxide, carbon dioxide and other hydrocarbon products, combustion pursuant to the present invention would be expected to provide the following partial oxidation products.
TABLE 1______________________________________Moles Component Wt. % Vol. %______________________________________15 Hydrogen Peroxide 51.0 36.93 Methyl Alcohol 6.6 8.72 Formaldehyde 6.0 7.63 Acetaldehyde 13.2 17.52 Acetone 11.6 15.22 Propylene Oxide 11.6 14.127 100.0 100.0______________________________________
FIG. 2 depicts a preferred embodiment of the instant invention, wherein a generator 100 (see FIG. 1) produces hydrogen peroxide for oxidizing cyanide species in a cyanide-containing fluid stream, while generating organic material optionally useful to enhance downstream microbial action on residual cyanide content. Cyanide-containing fluid, supplied to the generator 100 via fluid path 18, is preferably waste fluid from a gold-extraction or other mining operation. Air is supplied to the generator 100 via fluid path 11 and fuel is supplied to the generator 100 via fluid path 10. The fuel and air undergo combustion which is quenched by the cyanide-containing fluid to produce hydrogen peroxide and organic material. In order to oxidize the cyanide, the fuel, air, and water flow rates are adjusted to maximize the production of hydrogen peroxide. The hydrogen peroxide and the organic material are mixed with the cyanide-containing fluid stream in the generator 100 during and immediately after combustion. The discharge of the generator is directed to a holding volume 200 via fluid path 9.
The holding volume 200 can be a pond or pit which contains microbes that metabolize residual cyanide. The nature of indigenous cyanide-removing microbes varies depending on locale, but microbes capable of effecting the breakdown of cyanide species are found in virtually all habitats. Accordingly, organic materials can be produced, according to the present invention, that can be used to enhance growth (and, hence, the effectiveness) of cyanide-degrading microbes in holding ponds in diverse locations where metal extraction is effected. | A system for removing cyanide and related species from a cyanide-containing waste fluid, for example, of the sort generated by mining operations, includes means for generating hydrogen peroxide by the burning of a fuel and the quenching of that burning with the waste fluid. At least a portion of the cyanide content of the waste fluid is eliminated by oxidation with the hydrogen peroxide, and the quenching can also provide organic material to serve as a carbon source for microbes which degrade residual cyanide in the treated waste stream. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 07/757,691, filed on Sep. 11, 1991 now issued as U.S. Pat. No. 5,534,900 and a continuation-in-part of U.S. patent application Ser. No. 08/259,554, filed Jun. 14, 1994 now issued as U.S. Pat. No. 5,513,431, which is a continuation of U.S. patent application Ser. No. 08/025,850 filed Mar. 3, 1993, now abandoned, which is a divisional of U.S. patent application Ser. No. 07/757,691 filed Sep. 11, 1991, issued as U.S. Pat. No. 5,534,900, and a continuation-in-part of U.S. patent application Ser. No. 08/069,198, filed May 28, 1993, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an ink jet recording apparatus which ejects ink droplets towards to a recording medium in response to electric drive pulses.
2. Description of the Related Art
Ink jet recording apparatuses have become popular in recent years due to their numerous merits, including quiet operation while printing, the ability to print at high speed and the ability to use low-cost plain paper. The ink-on-demand type ink jet recording apparatus (in which ink is ejected only when printing is required) has become the most common type of ink jet printer because it is not necessary to retrieve ink not used for printing.
A conventional ink-on-demand ink jet recording apparatus is described in Japanese Laid-Open Application JP-A-79171/1980. This recording apparatus provides plural electrostrictive distortion bodies (piezoelectric devices), which are linked to each ejection chamber. When activated by digital electric pulse, the piezoelectric element mechanically distorts one or more walls of its respective ejection chamber, to momentarily increase pressure inside the ejection chamber and force expulsion of an ink drop. One can actually control the volume of ink drop emitted as well, by controlling the length or magnitude of the driving pulse. Thus, a good gradient image can be obtained using the above-described ink jet head by simple application of a requisite pulse information to the desired piezoelectric elements contained in the head, at least in theory.
With this type of conventional ink jet recording apparatus, however, it is extremely difficult and time-consuming to affix the piezoelectric device to the ejection chamber, thus making manufacturing difficult and prone to error. Plus, in practice, the thickness of conventionally manufactured piezoelectric devices tends to vary greatly, and the thickness of the adhesive applied to attach them to a chamber wall also fluctuates. Together, these factors produce undesirable scattering in ejection chamber responsiveness, which can degrade output and even shorten the life of the head. Thus, it is, in fact difficult to precisely control the size of the ink droplets according to the gradient signal.
In addition, the drive voltage required to obtain an enough deflection increases as the size of the piezoelectric device (especially unimorphic piezoelectric devices) decreases, and it is therefore difficult to form small electrostrictive bodies, mount them in a high density package, and drive the electrostrictive bodies with a relatively low drive voltage. Therefore, using piezoelectric device technology in high density, multiple nozzle ink jet head implementations suitable for high resolution gradient image printing without high drive voltages is exceedingly difficult.
It is, therefore an object of the present invention to provide an ink jet recording apparatus for printing high resolution gradient images using a low drive voltage by easily and precisely controlling the ink ejection volume according to a digital gradient signal describing the gradient of each pixel.
SUMMARY OF THE INVENTION
To achieve the above and related objects, an ink jet recording apparatus according to the present invention comprises an ink jet head and a drive means. This ink jet head includes a plurality of nozzles to emit ink droplet patterns; and a corresponding plurality of ejection chambers in communication with the respective nozzles and drawing ink from preferably a common ink cavity. Each ejection chamber will include an electrostatic actuator comprising a diaphragm provided in part of a wall member of the ejection chamber, and an electrode opposing said diaphragm with a predetermined gap there between. The drive means will selectively apply a pulse voltage to each actuator so that ink droplets are ejected from said nozzles by deforming the diaphragms by means of electrostatic force. This ink jet recording apparatus of the preferred and alternative embodiments is further characterized in that the electrostatic actuators will include multiple independent electrodes opposing a single diaphragm; and the drive means will apply a pulse voltage to a predetermined number of electrodes within a particular electrostatic actuator according to a gradient signal so that ink droplets of a desired volume are ejected relating to said gradient signal.
In addition the applicants have found, it difficult to set the deflection (ink ejection-volume) of the diaphragm when a voltage is applied to two electrodes of equal area to precisely twice the deflection when the voltage is applied to only one electrode. This is because the diaphragm tends to deflect in a somewhat irregular and nonlinear fashion in response to different numbers of electrodes being energized. As described in more detail in reference to the embodiments, the present invention circumvents this problem by disposing a support member supporting the diaphragm between adjacent electrodes. As a result, when a voltage is applied to only one of these electrodes, deformation of the diaphragm can be suppressed to the point where it will not deflect excessively. Furthermore, with the supporting member in place, deflection can be uniformly determined according to the known area of its associated electrodes, so that the ink ejection volume can be easily controlled.
The ink jet recording apparatus according to the present invention operates by applying a pulse voltage between a diaphragm and the opposing electrodes, thereby charging the electrostatic actuator consisting of the diaphragm and opposing electrodes. When charge builds to a sufficient degree, the diaphragm is deflected by the Coulomb's force acting between the diaphragm and electrode. Thereafter, when the charge stored by the electrostatic actuator is then rapidly discharged, the restoring force resulting from the elasticity of the diaphragm itself causes the pressure inside the ejection chamber to rise instantaneously, thereby ejecting an ink droplet from the nozzle.
By using an electrostatic actuator which includes multiple independent electrodes opposing the one diaphragm, and a drive means which tailors activation of a number of these electrodes based on a received gradient signal as described herein below, the ink ejection volume per nozzle (i.e., the size of the dot formed on the recording medium) varies according to the number of electrodes to which the pulse voltage is applied. As a result, it is possible to digitally control the ink jet volume and achieve a gradient image by selecting the electrodes to which the pulse voltage is applied.
It should also be noted that because the displacement area of the diaphragms can be freely adjusted by varying the area of the corresponding electrodes, the desired ink ejection volume can also be selected by varying the combination of electrodes to which the pulse voltage is applied.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the invention may be had when the following description of the alternative embodiments is considered in conjunction with the following drawings, in which:
FIG. 1 is a partially exploded view and cross section of an ink jet recording apparatus according to the first embodiment of the present invention;
FIG. 2 is a side cross section of the ink jet recording apparatus according to the first embodiment of the present invention after assembly;
FIG. 3 is a plan view of FIG. 2 at line A--A;
FIG. 4 is a plan view of the electrode portion of the ink jet recording apparatus according to the first embodiment of the present invention;
FIG. 5 is a circuit diagram of the drive circuit in the ink jet recording apparatus according to the first embodiment of the present invention;
FIG. 6 is a plan view of the electrode part of the ink jet recording apparatus according to the second embodiment of the present invention;
FIG. 7 is a partially exploded view and cross section of an ink jet recording apparatus according to the third embodiment of the present invention;
FIG. 8 is a cross section of the electrode part of an ink jet recording apparatus according to the fourth embodiment of the present invention;
FIG. 9 is a partially exploded perspective view of the ink jet head shown in FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The presently preferred embodiments of the present invention are described hereinbelow with reference to the accompanying figures, of which FIG. 1 is a partially exploded view and cross section of the major components of an ink jet recording apparatus according to the first embodiment of the present invention.
As shown in FIG. 1, this first embodiment is an edge ejection type ink jet recording apparatus whereby the ink droplets are ejected from nozzles 4 on the edge of substrate 2. FIG. 2 is a side cross section of the assembled ink jet head; FIG. 3 is a plan view through line A--A in FIG. 2; and FIG. 4 is a plan view of the electrode part of the ink jet recording apparatus according to the first embodiment of the invention.
As is evidenced from these figures, ink jet head 12 is the major component of this ink jet recording apparatus, and has a laminated structure achieved by stacking and bonding three substrates 1, 2, and 3 together.
The middle substrate 2 is a silicon substrate comprising: plural parallel nozzle channels 21 formed in the surface of and at equal intervals from one edge of middle substrate 2 to form plural nozzles 4; recesses 22 continuous to the corresponding nozzle channels 21 to form ejection chambers 6, the bottom wall of which comprises a diaphragm 5. Narrow channels 23 functioning as the ink inlets and forming orifices 7 are disposed at the backs of recesses 22. Recess 24 forms a common ink cavity 8 for supplying ink to each ejection chamber 6 through orifices 7. Recesses 25 form vibration chambers 9 for placement of the electrodes below diaphragm 5 as described in more detail hereinbelow. Recesses 25 are preferably etched to a depth of 0.275 microns. Nozzle channels 21 are preferably separated at a 0.508 mm pitch distance and are 60 microns wide.
Borosilicate glass is used for the upper substrate 1 bonded to the top surface of middle substrate 2. Bonding upper substrate 1 to middle substrate 2 completes formation of nozzles 4, ejection chambers 6, orifices 7 and ink cavity 8. Ink supply port 14 opening into ink cavity 8 is also formed in upper substrate 1, and is connected to an ink tank (not shown in the figure) through connector pipe 16 and tube 17.
Borosilicate glass is also used for bottom substrate 3 and is bonded to the bottom surface of middle substrate 2. Before bonding substrate 3 to substrate 2, ITO (Indium-tin oxide) is sputtered to a 0.1 micron thickness on the surface of bottom substrate 3 to form the electrodes at the positions of the diaphragms 5 in middle substrate 2. Three electrodes 31, each of approximately the same area, are formed as shown in FIG. 4. Each electrode 31 independently connects to a drive circuit 26 via a dedicated lead 32 and terminal members 33. An insulation layer 34 used to prevent dielectric breakdown and shorting is then formed by sputtering a 0.1 micron thick borosilicate glass film over the entire surface of bottom substrate 3 except directly over the electrode terminal members 33. Bottom substrate 3 is then attached to middle substrate 2 in a manner described herein below to complete vibration chambers 9.
Upper substrate 1 and middle substrate 2 are anodically bonded at 340° C. by applying an 800-V charge, and middle substrate 2 and bottom substrate 3 are bonded under the same conditions to assemble the ink jet head as shown in FIG. 2. Drive circuit 26 is then connected between middle substrate 2 and terminal members 33 of electrodes 31 to complete ink jet recording apparatus 10. Ink 11 is supplied from the ink tank (not shown in the figures) through ink supply port 14 into middle substrate 2 to fill the ink path, including ink cavity 8 and ejection chambers 6. Ink droplets 13 are ejected from nozzles 4 toward recording medium 15.
FIG. 5 is a detailed circuit diagram of drive circuit 26. The print data signal containing gradient information is sent from the host apparatus (not shown in the figures) in a known manner and received by the controller 110. The controller in this embodiment is configured to decode three bits per nozzle based on the print data signal because three electrodes 31a, 31b, and 31c are provided opposite each diaphragm as shown in FIG. 4. For example, only that part of diaphragm 5 (indicated by the dotted line in FIG. 5) corresponding to electrode 31a is deflected by means of the Coulomb's force acting between diaphragm 5 and electrode 31a, when only transistor 101a is driven. The charge stored between diaphragm 5 and electrode 31a is then discharged by turning transistor 101a off and transistor 102a on. As a result, the restoring force created by the elasticity of diaphragm 5 instantaneously increases the pressure in ejection chamber 6, thereby ejecting an ink droplet corresponding to the volume indicated by the dotted line in FIG. 5 from the nozzle. The charge/discharge speed of the electrostatic actuators is set to predetermined values by means of resistors 103a and 104a.
The ink jet volume can therefore be selected from any of four levels by applying the pulse voltage to all, two, one, or none of the electrodes, and a four gradient image can be recorded by thus controlling the diameter of the dot forming each pixel. In tests using ink jet head 12 and drive circuit 26 described above incorporated into a printer driven with a 38-V drive voltage and 3.3 kHz drive frequency, an ink ejection volume of approximately 0.04 μcc was obtained when the pulse voltage was applied to only electrode 31a, approximately 0.08 cc when applied to electrodes 31a and 31b, and approximately 0.12 μcc when applied to electrodes 31a, 31b, and 31c.
A plan view of a second embodiment of the present invention is shown in FIG. 6. As in the first embodiment described above and shown in FIG. 4, three electrodes are formed for each diaphragm. In this embodiment, however, the electrodes are formed with the area of electrodes 131a: 131b: 131c conforming to the ratio 2.5 : 5 : 10. By thus providing electrodes of different areas, the ink ejection volume can be selected from a larger number of driven electrode area combinations, and a gradient image having six levels can be achieved by similarly varying the pixel dot diameter. In tests using ink jet head 12 and drive circuit 26 described above in reference to FIG. 6, which was incorporated into a printer driven with a 40-V drive voltage and 3.3 kHz drive frequency, an ink ejection volume of approximately 0.015 μcc was obtained when the pulse voltage was applied to only electrode 131a. Approximately 0.03 μcc was obtained when a pulse signal was applied to only electrode 131b, and approximately 0.06 μcc was obtained when applied solely to electrode 131c. Approximately 0.05 μcc was obtained when a pulse was applied to both electrodes 131a and 131b, and approximately 0.12 μcc was expelled when applied to all three electrodes 131a, 131b, and 131c.
FIG. 7 is a partially exploded view and cross section of the major components of an ink jet recording apparatus according to a third embodiment of the present invention. As shown in FIG. 7, this is a face ejection type ink jet recording apparatus which ejects the ink droplets from nozzle holes 4 formed in the face of the substrate.
Also, as shown in FIG. 7, ink jet head 42 is the major component of this ink jet recording apparatus, and has a laminated structure achieved by stacking and bonding three substrates 61, 62, and 63 together.
The middle substrate 2 is a 400 micron thick, (110) surface orientation silicon substrate. Ejection chambers 6 are formed from recesses 22, at the backs of which are formed narrow channels 23 functioning as the ink inlets and forming orifices 7. Preferably, these ejection chambers 6 are formed at a pitch of 0.14 mm, and are each 100 microns wide. Bottom walls etched to a 3 micron thickness form the diaphragm 5 for each ejection chamber 6. Recess 24 forms a common ink cavity 8 for supplying ink to each respective ejection chamber 6. A thermal oxidation film 88 is formed to a 0.15 micron thickness on the bottom surface of middle substrate 62 to prevent shorting.
Borosilicate glass is used for the bottom substrate 63 which will eventually be bonded to the bottom surface of middle substrate 62. Recesses 40 forming vibration chambers 9 when bottom substrate 63 is bonded to middle substrate 62 are etched to a depth of 0.3 μm. ITO is then sputtered to a 0.1 μm thickness inside recesses 40 to form two electrodes 231a and 231b and their corresponding lead 32 and terminal 33 members. The surface area ratio of electrodes 231a and 231b is approximately 1:2.
In this embodiment, upper substrate 61 bonded to the top surface of middle substrate 62 is a stainless steel (SUS), 70 micron thick plate comprising nozzles 4 for ejecting the ink. Ink supply port 14 opening into ink cavity 8 is also formed in upper substrate 61, and is connected to an ink tank (not shown in the figure) through connector pipe 16 and tube 17.
Drive circuit 26, as shown in FIG. 5, is then connected between middle substrate 62 and terminal members 33 to complete the ink jet recording apparatus.
In similar tests driving this ink jet recording apparatus by applying a 40-V drive voltage from drive circuit 26 to electrodes 231a and 231b as described above in the first embodiment, an ink jet volume of approximately 0.04 gcc was obtained when the pulse voltage was applied to only electrode 231a, and was approximately 0.08 μcc when applied to both electrodes 231a and 231b.
FIG. 8 is a cross section diagram of the electrode member according to the fourth embodiment of the present invention.
FIG. 9 is a partial exploded perspective view of the ink jet head according to this embodiment.
Bottom substrate 3 is a borosilicate glass substrate comprising plural channels separated by stay walls (support member) 202. These channels form vibration chambers 9a, 9b, and 9c when bottom substrate 3 is bonded to silicon middle substrate 2. Electrodes 31a, 31b, and 31c are provided in the bottom of the corresponding vibration chambers 9a, 9b, and 9c separated by gap G. Each of the vibration chambers is formed to the same 0.3 μm depth, and the electrodes are formed by sputtering a 0.1 micron thick ITO film in a desired electrode pattern with each electrode encompassing approximately the same area.
Diaphragms 5 of middle substrate 2 are formed simultaneously with formation of ejection chambers 6 by doping boron to the bottom side of the substrate at a concentration of 1×10 20 /cm 3 to a depth of 1 micron by ion injection, patterning a thermal oxidation film on the surface of middle substrate 2 using a photolithography technique after heat diffusion, and then etching the exposed silicon with a KOH solution (potassium hydroxide). This is possible because the high concentration boron region is resistant to etching when utilizing a KOH solution, and 3 μM thick diaphragms 5 can thus be obtained using these areas (the etch stopping layer). After etching is completed, a thermal oxidation film 88 is formed to a 0.15 micron thickness on the bottom surface of middle substrate 2 to prevent shorting between the diaphragm and electrodes. The ink jet head is then assembled by bonding the three substrates using the same process described above in reference to the first embodiment.
By separating and supporting the vibration chambers below the diaphragms as described in this embodiment, the elasticity of the thin diaphragms can be strengthened to achieve sufficient ink ejection-performance. This technique also makes it possible to manufacture high precision diaphragms because it is possible to use silicon "etch stop" techniques.
It is difficult, for example, to set the deflection of the diaphragms (ink ejection volume) when a voltage is applied to both of two same-area electrodes to precisely twice the deflection when the voltage is applied to only one electrode because the diaphragms deflect irregularly. However, by providing stay walls supporting the diaphragms between adjacent electrodes as in the present embodiment, deformation of the diaphragm is suppressed when a voltage is applied to only one of the adjacent electrodes. The diaphragm will therefore not deflect excessively, diaphragm deflection can be uniformly determined according to the predetermined area of the electrode, and ink ejection volume can therefore be easily controlled.
As described hereinabove, an ink jet recording apparatus according to the present invention can eject ink droplets with the ink ejection volume precisely controlled by means of a simple control technique according to a specific pixel gradient based on a digital gradient signal, and can print high resolution gradient images using a low drive voltage.
The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, materials, components, circuit elements, wiring connections and contacts, as well as in the details of the illustrated circuitry, construction and method of operation may be made without departing from the spirit of the invention. | An ink jet recording apparatus capable of ejecting ink droplets in which the volume is precisely and easily controlled. The gradient of the pixel to be printed, based on a digital gradient input signal, is provided for printing high resolution gradient images using a low drive voltage in this ink jet head. More specifically, the ink jet recording apparatus of the present invention will include a diaphragm formed at one part of a wall of each independent ejection chamber, with electrodes formed opposite each diaphragm and spaced therefrom at a predetermined gap distance. Ink droplets are selectively ejected from nozzle openings in the ejection chamber by applying a voltage to generate an electrostatic force which momentarily deforms the diaphragm. Moreover, plurality of independent electrodes oppose each diaphragm and a pulse voltage is applied to a predetermined number of electrodes according to a gradient signal to eject ink droplets of a volume determined by the gradient signal. | 2 |
This invention may be manufactured by or for the Government, for governmental purposes, without the payment of any royalties thereon or therefor.
This application is a continuation-in-part of my parent application, Ser. No. 973,642 now U.S. Pat. No. 4,237,464 entitled "Radar Antenna", filed Dec. 26, 1978.
In this parent application, and in another continuation-in-part application filed by me May 9, 1980, Ser. No. 148,324 entitled "Pulse Train Generator of Predetermined Pulse Rate Using Feedback Shift Register", a pulse train generator is described which includes a shift register with feedback for producing an output pulse for every m clock pulses applied to the shift register stages. The feedback shift register normally has a maximal length 2 n -1, where n is the number of stages. Clock pulses are applied to the shift register until an all-ONE condition is reached; thereupon, (m-1) additional clock pulses, where m can be less than n, are applied and the states of the register stages can then be sensed. Appropriate gate circuits are added to the shift register, including an n-input inverting AND gate, depending upon the sensed register states, to inhibit certain shifts and to insure that the register is returned to the all-ONE condition upon arrival of every mth clock pulse. The pulse generator referred to above provides means for obtaining an output pulse for every m bits of the code length.
The feedback shift register, per se--without the added gate circuits--can be used, for example, for code generation, with the outputs being derived from each of the various stages (flip-flops) of the shift register.
In certain instances, owing generally to the sudden presence of noise or other transient disturbances, the shift register stages can be forced into a condition wherein the corresponding outputs of each and every one of the shift register stages (flip-flops) is a ZERO. In this abnormal condition, the feedback shift register cannot generate code; in other words, the shift register remains in a fixed or static condition. Similarly, if the feedback shift register is used, with appropriate additional gate circuitry, as a pulse generator, the output pulses would cease when the aforesaid abnormal static condition of the shift register occurs.
A digital technique for preventing static condition retention in n-stage feedback shift registers makes use of an n-input and AND gate receptive of the corresponding Q outputs of each of the flipflops and the output of the gate is coupled to an OR gate which is in series with the clocked AND gate in the Q input of the first stage. The other input to the OR gate is derived from the output of the Exclusive OR gate in the shift register feedback circuit. If all Q outputs are ZERO then all inputs to the n-input AND gate, viz., the Q outputs of all stages, are ONES. Consequently, a ONE is derived at the output of the n-input AND gate which is connected to one input of the OR gate. A ONE is derived at the output of the OR gate and, upon receipt of the next clock pulse, this ONE is transferred to the Q input of the first flipflop, thereby converting the ZERO in the Q output of the first stage from a ZERO to a ONE. Once one of the flipflop Q outputs is a ONE, normal shifting will ensue.
Similarly, for a pulse generator such as shown in my copending application entitled "Pulse Train Generator of Predetermined Pulse Rate Using Feedback Shift Register", an n-input AND gate and OR gate similar to that just described in connection with the shift register per se would be used, in addition to the inverting multiple input AND gate 45, 46 of the pulse generator circuit. In the same manner, a ONE would be derived when all n of the Q outputs are ZEROS (viz., all Q outputs are ONES) and the ONE from the added n-input AND gate would operate on the additional OR gate in series with the first flipflop to change the Q output of the first flipflop (stage) from a ZERO to a ONE and permit normal shift register operation to occur.
In many practical applications of code generation using a shift register, particularly when security is a factor, one may want a long code requiring several stages. Similarly, in pulse generation, such as described in my copending application entitled "Pulse Train Generator of Predetermined Pulse Rate Using Feedback Shift Register", the factor m may easily be of the order of one million, in which case the shift register would require 20 stages (2 20 -1=1048575).
If the digital technique just described is used in such cases, the n-input AND gate would be unduly complex and plagued by the well-known fanout problem.
In accordance with the invention, the false count correction can be obtained by the combination of a detector and an analog integrator and, in some cases, an inverter, for deriving a voltage level representing a ONE when, instead of the normal sequential changes in the output of ONES and ZEROS, there is a static condition in which all ZEROS appear in the Q outputs of all stages of the shift register.
This representative ONE voltage level, when coupled to a Q input of one of the shift register stages, causes the ZERO in that stage to shift from a ZERO to a ONE, whereupon, normal shift register action resumes.
In one embodiment of the invention, a detector and analog integrator, followed by an inverter, is positioned between the Q output of any one of the n stages of the shift register and an OR gate in the Q input of any of the n stages of the shift register. The detector may consist of a diode and a resistor in parallel and the integrator may consist of a capacitor in shunt with said detector. The detector and integrator may also be positioned between the Q output circuit of any of the n stages and an OR gate in the Q input circuit of any of the n stages; in this case, the inverter is omitted.
If the shift register is operating normally, the integrator output level will be substantially within the voltage range representative of a Q output of ONE. If ZEROS fill the shift register, this static condition will result in the output level of the detector-integrator approaching and eventually attaining a more negative value falling within a Q output voltage range of ZERO. In this static condition, this level, after inversion, is substantially equivalent to a ONE. This ONE output from the inverter in the output of the detector-integrator is applied to one of the inputs of the aforesaid OR gate and causes a ONE to be applied to the AND gate in the Q input of the stage with which the OR gate is associated. Upon receipt of the next clock pulse at the other input to this particular AND gate, a ONE is applied to the Q input of that stage and causes the ZERO already in that stage (that is, the Q output of that stage) to convert to a ONE. With a ONE in any one of the stages of the shift register, the latter no longer is stalled with a load of ZEROS and the normal shifting operation commences.
Alternatively, the input to the detector-integrator can be supplied from the Q output of any stage, with proper diode connections; in this case the abnormal operation would result in the output of the detector-integrator increasing positively until the voltage level comes within the voltage range representative of a ONE. With this arrangement, an inverter can be eliminated.
In a second embodiment of the invention, the combination of detector and integrator, previously described, forms a portion of the Exclusive OR circuit (which inherently incorporates an inverter) which is inputted from the Q and Q output of the n th stage and the Q and Q output of one of the remaining n-1 stages of the shift register. The output of the Exclusive OR gate, which incorporates the detector and integrator, forms one input to the clocked AND gate in the Q input circuit of the first stage of the shift register. The Q output level of one of the shift register stages connected to the Exclusive OR circuit is connected to the detector thus incorporated into the Exclusive OR circuit.
During normal operation, a series of ZEROS and ONES appear in the Q output circuits of each of the shift register stages which are connected to the inputs of the Exclusive OR gate so that the integrator output level will tend to remain within a voltage range corresponding to a ONE. If for some reason, an undesirable condition occurs wherein ZEROS appear in the Q outputs of all stages of the shift register, the static input to the integrator will result in the integrator output slowly becoming mere negative until a level is reached which falls within the range corresponding to a ZERO. Because of inversion in the Exclusive OR gate, this ZERO condition is converted into a ONE condition. This ONE then is applied to the clocked AND gate in the Q input circuit of the first stage of the shift register.
The integration techniques already described obviously can be applied to a pulse generator using a feedback shift register such as described and illustrated in my copending application, Ser. No. 148,324, filed May 9, 1980, entitled "Pulse Train Generator of Predetermined Pulse Rate Using Feedback Shift Register", which is a continuation-in-part application based on my parent application, Ser. No. 973,642, filed Dec. 26, 1978.
The invention and its mode of operation will be more fully understood from the following detailed description taken in conjunction with the drawing wherein.
DESCRIPTION OF THE DRAWING
FIG. 1 is a block diagram of a feedback shift register incorporating one embodiment of an integration circuit according to the invention.
FIG. 2 is a circuit diagram showing the combination of detector, integrator and inverter shown in FIG. 1;
FIG. 3 is a fragmentary block diagram of a feedback shift register showing an alternate means of implementing the embodiment shown in FIG. 1;
FIG. 4 is a fragmentary block diagram of a feedback shift register incorporating an alternative embodiment of the integration circuit of FIGS. 1 and 2; and
FIG. 5 discloses a circuit diagram of a portion of the Exclusive OR circuit incorporating a detector and integrator such as shown in FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to FIG. 1 of the drawing, an n-stage shift register is shown with an Exclusive OR gate 15 and an inverter 16 connected between the final stage or flipflop FF7 and the first stage FF1. The Exclusive OR gate 15 enables the maximum count of the shift register to increase from n to 2 n -1. As shown by way of example in FIG. 1, the shift register includes seven flipflops FF1 through FF7, each of which includes first and second inputs--indicated at the top and bottom of each flipflop--and first and secong complementary outputs Q and Q. The inputs to the Exclusive OR gate 15 are derived from the Q outputs of the last flipflop FF7 and one of the other flipflops; in this case, the next to last flipflop FF6 has been chosen by way of example. The Exclusive OR gate 15 has a ONE in the output whenever the two Q outputs Q 6 and Q 7 of stages FF6 and FF7 are of differing state and has a ZERO in the output whenever the two outputs Q 6 and Q 7 are either both ones or are both ZEROS.
The number n of flipflops used will determine the normal maximum length of the feedback shift register, which is given by 2 n -1 when an Exclusive OR gate is used in the feedback circuit. For the seven stage shift register shown in FIG. 1, the maximum length would be 2 7 -1=127. After 127 clock pulses C, the outputs of the shift register stages will resume its original sequence. If less stages, say 6 stages, are used, the maximum length of the shift register would be 63. The shift register of FIG. 1 includes a plurality of AND gates 21 to 27, the output of each of which is connected to a first (Q) input of a corresponding one of the flip-flops FF1 to FF7. A plurality of AND gates 31 to 37 are further provided; the output of each of the AND gates 31 to 37 is connected to a second (Q) input of respective flipflops FF1 to FF7. All of the AND gates 21 to 27 and 31 to 37 are receptive of clock pulses C from a clock circuit 8.
The shift register is so connected that the first or Q outputs of each of the first six stages FF1 to FF6 is connected to one of the inputs to that one of AND gates 22 to 27 which is in the first (Q) input of the next stage. For example, the Q 2 output from stage FF2 forms one input to the AND gate 23. The output of the Exclusive OR gate 15 is connected to one input of the AND gate 21 of the first stage FF1. Further the second or Q outputs of each of the first six stages is connected to an input of that one of the AND gates 32 to 37 which is in the second or Q input circuit of the next stage. For example, the Q 5 output from stage FF5 is connected to an input of AND gate 36. The output of the inverter 16 is connected to an input of the AND gate 31 of the first stage FF1. Clock pulses C from clock circuit 8 are applied to the other input of the various AND gates 21 to 27 and 31 to 37. Whenever a clock pulse arrives at the AND gates of a given flipflop, the AND gate in question will be enabled, provided the other input to that AND gate directly connected to the previous stage, or to the Exclusive OR gate 15 and inverter 16, as the case may be, is ONE, and if the state of the preceding stage is a ONE, it can be transferred to the next flipflop. If the output of the Exclusive OR gate 15 is a ONE when a clock pulse arrives at AND gate 21 and, hence, the output of the inverter 16 is a ZERO when a clock pulse arrives at AND gate 31, these outputs can be transferred to the Q or Q input circuit, respectively, of the first flipflop FF1. If the Q or Q output of a given stage is ZERO, that ZERO can be changed to a ONE upon arrival via the appropriate AND gate of a ONE at the corresponding Q or Q input circuit of that flipflop; that is to say, the state of the flipflop can be changes. The arrival of ZERO via the appropriate AND gate, on the other hand, will not affect a change of state of the associated flipflop.
As shown in FIG. 2, the detector 10 is receptive of the Q output of the one of the flipflops. By way of example, the output Q 4 of flipflop FF4 is connected to the detector 10 in FIG. 2.
As shown in FIG. 2, the detector 10 may consist of a diode 18 in parallel with a resistor 19 of a medium high resistance value which is much higher than the forward resistance of diode 18 but somewhat lower than the reverse resistance of the diode. The integrator 11 may consist of a capacitor which is fed by the detector 10. A voltage limiting diode 20 may also be included in parallel with the capacitor 11. The inverter 12 may be a convential transistor stage including a biasing resistor 17.
It will be noted that, if all Q outputs from flipflops FF1 to FF7 are ZEROS, that is to say, the shift register contains all ZEROS, there can be no normal sequential shifting of flipflop outputs and the Q output of every one of the stages of the shift register remains a ZERO.
It should be noted that with the first embodiment of FIGS. 1 and 2, wherein the detector-integrator combination is connected between the fourth stage FF4 and the first shift register stage FF1, the output of the inverter 12 is shown as connected to one input of an OR gate 13 while the other input of OR gate 13 is obtained from the Exclusive OR gate 15. This OR gate is here required to permit proper interaction between the Exclusive OR gate output and the first stage FF1 during normal operation without interference from the output of the detector-integrator.
As shown in FIG. 3, however, the detector-integrator combination can be disposed between one of the outputs of any of the flipflops and the first input circuit of any other flipflop. In other words, the output of the detector-integrator combination need not be coupled to the first input circuit of the first stage FF1 (the stage to whose first input circuit the output of the Exclusive OR gate 15 is coupled) but can be coupled to any of the AND gates 21 to 27.
In a case such as shown in FIG. 3, the added OR gate will be receptive of the output from the flipflop FF1 preceding the flipflop FF2 to which the output of integrator 11 is coupled.
It will be assumed that the input level to a given stage will be considered a ONE if the voltage level is more positive than -1.5 volts and will be considered a ZERO if it is more negative than -2.0 volts, corresponding, roughly, to a ONE output at the Q output of a flipflop more positive than -0.5 volts and a ZERO at the Q output of the flipflop which is more negative than -3.0 volts.
Assuming normal shifting register operation and the appearance of a ONE input to flipflop stage FF4, the voltage Q4 from the first output circuit of flipflop FF4 supplied to the parallel combination of diode 18 and register 19 (FIG. 2) of the detector 10, say, 0 volts, will appear across the integrator capacitor 11 after a relatively short period determined by the time constant of the detector circuit; it will be noted that the diode will be forward biased by the 0 volt input and will be very low resistance. The integrator voltage will tend to remain at about 0 volt so long as successive ONES appear at the Q output of stage FF4. However, in normal operation of the shift register, ZEROS will occur statistically about as often as ONES. Upon arrival of a ZERO, viz., about -3.5 volts, at the output of flipflop FF4, the detector will be reverse biased by this -3.5 volt level and will have a very high resistance; a resistance of medium high resistance is connected in parallel with this diode. The integrating capacitor will now discharge through the medium high resistance at a relatively slow rate, so that, upon arrival of the next ONE output at flipflop FF4, the voltage across the integrator capacitor will still be close to the previous value of 0 volt. After inversion in inverter 12 of this ONE voltage, a ZERO is obtained and will be applied to the OR gate 13. This will have the effect of flipflop FF1 of placing it under the control of the output of the Exclusive OR gate 15.
Assuming abnormal operation (all ZEROS at the various Q outputs), there will always be -3.5 volts input to the detector from the output Q 4 of flipflop FF4. Since the diode is now reverse-biased, the approximately 0 volt level previously existing at the diode output, because of the presence of the last ONE, will, as before, discharge through the medium high resistance in parallel with the diode. This gradual negative-going voltage across the integrator capacitor will continue so long as the ZEROS exist at the output Q 4 until, finally, the integrator capacitor voltage reaches a level of about -2.0 volts, which is equivalent to a ZERO at the input of the inverter 12. This ZERO is inverted to a ONE by the inverter 12 and this ONE is applied to the OR gate 13. This ONE passes the AND gate 21 at the input circuit of the first flipflop FF1 and changes the output at Q, from a ZERO to a ONE. Once a ONE appears at one of the Q outputs of the shift register, normal shift register operation resumes.
As previously explained, the input to the detector-integrator 10, 11 can be supplied from the Q (second) output of any of the shift register flipflops, as shown in FIG. 3 of the drawing.
In such a case, the connections of the diode 18 are reversed from that shown in FIG. 2 so that the diode is reverse biased during the presence of a ONE at the Q output of that flipflop. During normal operation, the capacitor voltage of integrator 11 will tend to be about -3.5 volts in the presence of a ZERO input to the diode 18, since the diode would be forward biased. Upon appearance of a ONE at Q 4 the diode 18 becomes reverse biased; the integrator capacitor 11 would then discharge through medium high resistor 19 of detector 10 so that the capacitor voltage would tend to go slightly more positive, but still would remain near -3.5 volts so long as ZEROS were interspersed with ONES in the normal fashion. If, however, abnormal operation occurs, viz., ONES remain at all of the Q outputs, then the diode 18 remains reverse biased and the integrator capacitor discharges slowly and continuously in a positive direction through the detector resistor 19 until, eventually, the voltage level becomes more positive than -1.5 volts, which voltage level falls within the range of a ONE. This ONE now will be applied directly to the OR gate 13 which is in tandem with AND gate 22 associated with flipflop FF2. The other input to OR gate 13 will be derived from the first output circuit Q 1 of the preceding stage FF1. The aforesaid ONE will pass AND gate 22 in the first input circuit of flipflop FF2, thereby causing the first output Q 2 of flipflop FF2 to change from a ZERO to a ONE. At this time, normal operation of the shift register can resume. Note that, in this case, a ONE is derived from the detector-integrator 10, 11 during abnormal shift register operation, so that the inverter used in FIGS. 1 and 2 is not required.
Instead of using an integrator 11, with or without inverter 12, in the manner shown in FIGS. 1 and 2, the integrator may be incorporated in the Exclusive OR circuit 15, as shown in detail in FIGS. 1 and 5. The Exlusive OR gate 15 is inputted from the final stage (FF7 in FIG. 1) of the shift register and from one of the other stages of the shift register; in FIG. 1, the next to last stage FF6 of the shift register is chosen along with the last stage FF7.
The Exclusive OR circuit of FIG. 4, which incorporates the detector 10 and integrator 11, uses three NOR gates 61 to 63. The outputs Q 6 and Q 7 from flipflop FF6 and FF7 are supplied to NOR gates 61 and 62. By means of inverters 71 and 72, the outputs Q 6 and Q 7 can also be inverted so that the inputs to NOR gate 61 are Q 6 and Q 7 , while the inputs to NOR gate 62 are Q 6 and Q 7 . The outputs of NOR gates 61 and 62 are connected to the inputs of NOR gate 63 at points X and Y. The inverters 71 and 72 can be eliminated, if desired, simply by supplying outputs Q 6 and Q 7 from flipflops FF6 and FF7 directly to NOR gate 61 and by supplying outputs Q 6 and Q 7 from flipflops FF6 and FF7 directly to NOR gate 62.
As shown in FIG. 5, the Q input from a flipflop is applied to the diode 18 in shunt with resistor 19 and the output of this detector 10 changes an integrating capacitor 11 during periods of forward bias of diode 18. The integrator 11 is connected in series with a voltage limiting diode 20 which is biased from a positive supply through a resistor 19. The NOR gate 63 includes diodes 73 and 74 connected to points X and Y respectively. The NOR gate 63 further includes a transistor (inverter) stage 75 whose collector circuit contains a suitable biasing resistor 77 connected to a negative supply. The output terminal 78 of the transistor inverter 75 is connected to AND gate 21 associated with stage FF1 in FIG. 1.
The function of inversion is taken care of by the inverter 75 which is an inherent part of the Exclusive OR circuit; consequently, the inverter 12 of FIG. 2 is not needed.
As shown in FIG. 4, there is no requirement for an OR gate 13 following the detector-integrator circuit, as in the first embodiment shown in FIGS. 1 to 3.
Depending upon the construction of the AND gates and the construction of the flipflops, one may combine the detector and integrator, without inverter 12 or OR gate 13, with one of the AND gates 21 to 17 or with one of the flipflops FF1 to FF7.
Since the Q (second) outputs of all flipflops (stages) will be ONES during the abnormal shift register condition, and since the Q=ONE output of a flipflop cannot be converted by application to the corresponding Q input circuit of either a ZERO or a ONE, the output of the detector-integrator (with or without inverter) cannot be applied to the AND gates 31 to 37 or to inverter 16 to cure the abnormal condition. | A pulse train generator comprising a shift register with feedback for proing an output pulse for every m clock pulses applied to the shift register stages. The feedback shift register normally has a maximal length 2 n -1, where n is the number of stages. Clock pulses are applied to the shift register until an all-ONE condition is reached; thereupon, (m-1) additional clock pulses are applied and the states of the register stages can then be sensed. False count correction is obtained by the combination of a detector and an analog integrator. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to bandsaw machines having a flexible bandsaw blade trained around a plurality of wheels or pulleys to perform cutting operations and, more particlularly pertains to methods and apparatus for controlling the feeding of the bandsaw blade into workpieces to be cut in bandsaw machines.
2. Description of the Prior Art
The prior art concerning the present invention will be described, by way of example, about what is called a horizontal bandsaw machine, although the present invention is applicable not only to horizontal bandsaw machines but also to vertical bandsaw machines.
As is well known horizontal bandsaw machines comprise a base on which a workpiece or workpieces to be cut are to be placed and clamped and a cutting head assembly in which a flexible endlesss bandsaw blade is trained around a pair of wheels or pulleys, one of which is power driven to drive the bandsaw blade. In the cutting head assembly, the bandsaw blade is slidably held and guided with its cutting edge facing perpendicularly downwardly by a pair of guide means at the cutting zone where cutting is performed so that it may cut into the workpiece to be cut. The cutting head assembly is so arranged as to be raised away from and lowered toward the base by a hydraulic motor around a hinge pin or along one or more vertically disposed quide means. Thus, in each cutting cycle, the cutting head assembly is firstly raised and then lowered toward the base so as to enable the bandsaw blade being driven therein around the wheels to cut the workpiece which has been placed and clamped on the base.
In conventional bandsaw machines of the above described construction, a problem has been the fact that the bandsaw blade will be often deflected by the cutting resistance bacause of its flexible nature and will not cut into workpieces to be cut. The bandsaw blade will be deflected especially when cutting difficult-to-cut materials such as stainless steels and metal alloys which are generally hard and tough and are mostly subject to work hardening. When the bandsaw blade is deflected and cannot cut into workpieces, it will slide on the workpieces to be cut only to scratch them without performing any cutting, action with a result that a hard layer will be produced in kerfs of the workpieces because of work hardening. Such disadvantages with the conventional bandsaw machines will not only result in a lower cutting rate and a poor cutting accuracy but also will cause a short life of the bandsaw blade and a larger vibration and noise during cutting operations.
In order to solve the problems, the inventor invented a cutting method and apparatus in which the bandsaw blade will be intermittently fed and stopped from feeding into workpieces to be cut. In this arrangement, the bandsaw will be instantaneously stopped from feeding into the workpieces to be cut and then it will drastically into workpieces. Accordingly, the bandsaw blade will be effectively fed with impact into workpieces to be cut with a larger feeding force without scratching them even when cutting difficult-to-cut materials such as stainless steels and metal alloys which are subject to work hardening. However, it is disadvantageous that the bandsaw blade will be fed into workpieces to be cut with too large a feeding force and therefore each tooth of the bandsaw blade will be overworked under the too large feeding force and will be liable to brake. Also, since the bandsaw blade is mostly hydraulically controlled, it is further disadvantageous that shock waves in the hydraulic circuit have a harmful effect on the hydraulic equipment.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus for controlling the feeding of a bandsaw blade in bandsaw machines so that the bandsaw blade may be surely fed into workpieces to be cut without scratching them with no cutting action.
It is therefore another object of the present invention to provide a method and apparatus for controlling the feeding of a bandsaw blade in bandsaw machines so that the bandsaw blade may be properly fed into workpieces to be cut including those of difficult-to-cut materials which are subject to work hardening.
It is therefore another object of the present invention to provide a method and apparatus for controlling the feeding of a bandsaw blade in bandsaw machines so that the life of the bandsaw blade and the cutting accuracy may be increased and vibration and noise may be reduced even in cutting difficult-to-cut materials including those which are subject to work hardening.
It is a further object of the present invention to provide a method and apparatus which will control the feeding of a bandsaw blade in bandsaw machines so that shock waves may be prevented from occurring in the hydraulic circuit for moving the bandsaw blade to have no harmful effect on the hydraulic equipment.
In order to accomplish these objects, a bandsaw machine according to the present invention is provided with a controlling means for feeding the bandsaw blade into workpieces to be cut alternately fast and slow.
Other and further objects and advantages of the present invention will be apparent from the following descripion and accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principle thereof.
BRIEF DESCRIPION OF THE DRAWINGS
FIG. 1 is a front elevational view of a horizontal bandsaw machine embodying the principles of the present invention.
FIG. 2 is a diagrammatic illustration showing the horizontal bandsaw machine shown in FIG. 1 and its hydraulic circuit.
FIG. 3 is a front elevational view of a horizontal bandsaw machine showing another embodiment of the present invention.
FIGS. 4A and 4B are side and front elevational views respectively of a vertical bandsaw machine showing an additional embodiment of the present invention.
FIG. 5 is a front elevational view of a vertical bandsaw machine showing a further embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the horizontal bandsaw machine 1 comprises a box-like base 3 and a cutting head assembly 5 which is pivotally connected to the base 3 by means of a hinge pin 7 to be movable up and down toward and away from the same. The base 3 is provided at its top with a work-table 9 on which a workpiece W to be cut can be placed, and the work-table 9 is provided with a vise assembly 11 which has a fixed jaw 11f and a movable jaw 11m to clamp the workpiece W therebetween. The cutting head assembly 5 has spaced housing sections 13 and 15 connected with each other by a beam member 17 and is provided at its top with a control box 19. In the cutting head assembly 5, a pair of a driving wheel 21 and a driven wheel 23 having shafts 25 and 27 respectively, are enclosed in the housing sections 13 and 15, respectively, and a flexible endless bandsaw blade 29 is trained therearound so that it may be driven to make a cutting action when the driving wheel 21 is power driven. The bandsaw blade 29 is slidably held or guided with its cutting edge facing perpendicularly downwardly by a pair of a fixed guide assmbly 31 and a movable guide assembly 33 so that a cutting stretch may be provided therebetween at the cutting zone of the horizontal bandsaw machine 1. The fixed and movable guide assemblies 31 and 33 are mounted on a guided way 35 which is fixed to the beam member 17 in a manner such that they depend therefrom in parallel with each other. The fixed quide assembly 31 is fixedly mounted on the guide way 35, while the movable guide assembly 33 is so mounted that it may be fixed on the guide way 35 in operation but may be moved toward and away from the fixed guide assembly 31. The movable guide assembly 33 is moved on the guide way 35 to adjust the cutting stretch of the bandsaw blade 29 according to the size of the workpiece W to be cut. Also, the cutting head assembly 5 of the above described construction is so arranged as to be swung up and down around the hinge pin 7 by a hydraulic motor 37 of a cylinder type having a piston rod 39 to feed and return the bandsaw blade 29 into and away from the workpiece W to be cut. Thus, the cutting head assembly 5 will be raised when the hydraulic motor 5 is supplied with the hydraulic fluid, and it will be lowered by its own gravity when the hydraulic fluid is drained from the hydraulic motor.
Referring to FIG. 2 the hydraulic motor 37 is so arranged as to be supplied with the hydraulic fluid by a hydraulic pump 41 which is driven by a motor 43 and is connected with a hydraulic tank 45 through a conduit 47. The hydraulic pump 41 is connected to the hydraulic motor 37 by a conduit 49, a solenoid operated valve assembly 51, a conduit 53, a check valve 55 and another conduit 57 to deliver the hydraulic fluid into the hydraulic motor 37. As is conventional, there is provided a relief valve 59 which is connected to the conduit 49 between the hydraulic pump 41 and the solenoid operated valve assembly 51 to return the hydraulic fluid to the hydraulic tank 45 at need. Also, a pilot operated check valve 61 is connected by a conduit 63 to the conduit 57 between the check valve 55 and the hydraulic motor 37 and it is further connected to the solenoid operated valve assembly 51 by a pilot conduit 67 for a purpose to be seen hereinafter. The solenoid operated valve assembly 51 is of a three position type having two solenoids SOL 1 and SOL 2 and four ports A, B, P and T. Also, the solenoid operated valve assembly 51 is so arranged that the ports A and B will be connected with the ports T and P, respectively, when the solenoid SOL 1 is energized and the ports A and B will be connected with the ports P and T, respectively when the solenoid SOL 2 is energized. In the solenoid operated valve assembly 51, the port P is connected to the hydraulic pump 41 by the conduit 49, and the port T is connected to the hydraulic thank 45 by a drain conduit. Also, the ports A and B of the solenoid operated valve assembly 51 are connected to the pilot conduit 67 and the conduit 57, respectively, leading to the pilot operated check valve 61 and the check valve 55, respectively. The pilot operated check valve 61 is so arranged as to normally or usually block the hydraulic fluid in the hydraulic motor 37 but allow it to drain therethrough when acted on by the pilot pressure of the hydraulic fluid delivered through the pilot conduit 67 from the solenoid operated valve assembly 51. The check valve 55 is so arranged as to allow the hydraulic fluid to go to the hydraulic motor 37 from the solenoid operated valve assembly 51 but prevent it from going back therethrough. Thus, when the solenoid SOL 1 of the solenoid operated valve assembly 51 is energized, the hydraulic fluid will be delivered from the hydraulic pump 41 into the hydraulic motor 37 to raise the cutting head assembly 5. When the solenoid SOL 2 of the solenoid operated valve assembly 51 is energized, the hydraulic fluid from the hydraulic pump 41 will be applied to the pilot operated valve 61 to enable the hydraulic fluid in the hydraulic motor 37 to drain therethrough to lower the cutting head assembly 5.
Referring further to FIG. 2, the pilot operated check valve 61, which is connected with the hydraulic motor 37 by the conduits 63 and 57, is connected to a valve means such as a flow control valve assembly 69 so as to drain alternately fast and slow the hydraulic fluid from the hydraulic motor 37. The pilot operated check valve 61 is connected to the flow control valve assembly 69 through a conduit 71, a reducing valve 73 and a conduit 75. The reducing valve 73 is provided to adjustably control the hydraulic fluid prevailing in the hydraulic motor 37 to a desired pressure.
The flow control valve assembly 69 is so arranged as to continuously alternately increase and decrease the flow of the hydraulic fluid draining out of the hydraulic motor 37 by a suitable control motor 77 such as a servomotor or a stepping motor. More particularly, the control motor 77 is so arranged as to be continuously controlled by a suitable means such as a numerical control or computer to continuously control the flow control vavle assembly 69 so as to alternately increase and decrease the flow of the hydraulic fluid passing therethrough. Thus, the flow of the hydraulic fluid draining out of the hydraulic motor 37 will alternately be increased and decreased by flow control valve assembly 69 to lower the cutting head assembly 5 alternately fast and slow to feed the bandsaw blade 29 altermately fast and slow into the workpiece W to be cut.
In the above described arrangement, in operation the solenoid SOL 1 of the solenoid operated valve assembly 51 is firstly energized to supply the hydraulic fluid from the hydraulic pump 41 into the hydraulic motor 37 to raise the cutting head assembly 5 together with the bandsaw blade 29. Then, in order to lower the cutting head assembly 5 to enable the bandsaw blade 29 to cut the workpiece W, the solenoid SOL 1 of the solenoid operated valve assembly 51 is de-energized and simultaneously the solenoid SOL 2 of the same is energized, and also control motor 77 is put in motion. The solenoid operated valve assembly 51, will flow the hydraulic fluid through the pilot conduit 67 from the hydraulic pump 41 to enable the pilot operated check valve 61 to drain the hydralic fluid from the hydraulic motor 37 therethrough toward the flow control valve assembly 69. Also, the flow control valve assembly 69 will enable the hydraulic fluid to drain alternately fast and slow from the hydraulic motor 37 into the hydraulic tank 45 through the pilot operated check valve 61 when control motor 77 is in motion. Thus, when the solenoid SOL 2 of the solenoid operated valve assembly 51 is kept energized and the control motor 77 is kept in motion, the cutting head assembly 5 will be lowered alternately fast and slow to enable the bandsaw blade 29 to cut into the workpiece W alternately fast and slow.
As has been described above, the bandsaw blade 29, according to the present invention, will be fed alternately fast and slow into the workpiece W by the cutting head assembly 5 when the flow control valve assembly 69 is continuously controlled by the control motor 77. Accordingly, the bandsaw blade 29 will be fed into the workpiece without being overworked and therefore without being deflected but with a large feeding force which has been set to optimum for cutting the workpiece W. Therefore, the bandsaw blade 29 according to the present invention will not slide on the workpiece W nor scratch the same causing a work hardening, and it will make an accurate cutting action at a higher cutting rate and with less vibration and noise. Also, since the bandsaw blade will not only not slide on the workpiece W without making a cutting action but also will not be overworked, the life of the bandsaw blade 29 will be greately increased according to the present invention.
Furthermore, since the hydraulic fluid is continuously drained alternately fast and slow from the hydraulic motor 37 without stopping, shock waves will not occur in the hydraulic circuit that have a harmful effect on the hydraulic equipment as well as the bandsaw blade 29.
Referring to FIG. 3, there is shown another embodiment of the present invention in which a horizontal handsaw machine 1' comprises a cutting head assembly 5' which is so disposed as to be raised and lowered vertically along a main post 79 and an auxiliary post 81 to carry the bandsaw blade 29'. The main post 79 and the auxiliary post 81 are vertically disposed on a base 3' in paralled with each other to vertically guide the cutting head assembly 5' toward and away from the work-table 9'. Also, in this embodiment, the cutting head assembly 5' is so arranged as to be raised and lowered along the main and auxiliary posts 79 and 81 by a nut 83 and a lead screw 85 which is driven by a suitable means such as a servomotor 87. The nut 83 is fixed to a portion of the cutting head assembly 5', the lead screw 85 is vertically disposed along the main post 79 in engagement with the nut 83 and the servomotor 87 is mounted on the main post 79 so as to rotate and drive the lead screw 85. In this arrangement, when the lead screw 85 is rotated by the servomotor 87, the cutting head assembly 5' will be raised and lowered by the lead screw 85 through the nut 83 to raise and lower the bandsaw blade 29'. According to the present invention, the lead screw 85 is driven alternately fast and slow by the servomotor 87 to lower the cutting head assembly 5' alternately fast and slow so that the bandsaw blade 29' may be fed alternately fast and slow into the workpiece W. Thus, it will be understood that the horizontal bandsaw machine 1' shown in FIG. 3 can perform cutting actions in all the same manner as the horizontal bandsaw machine 1 shown in FIGS. 1 and 2 when the lead screw 85 is driven alternately fast and slow by the servomotor 87.
As has been far described in the above, the purposes of the present invention can be accomplished by providing a bandsaw machine with a means for feeding the bandsaw blade into workpieces to be cut alternately fast and slow. However, it will be understood that the purposes of the present invention can be attained by providing a means for feeding workpieces to be cut into a bandsaw blade alternately fast and slow, although the bandsaw blade has been described as fed into workpieces in the preferred embodiments. Accordingly, the present invention is applicable not only to horizontal bandsaw machines but also to vertical bandsaw machines in which workpieces to be cut are moved and fed into a bandsaw blade which is driven at a fixed position.
Referring now to FIGS. 4A and 4B, a vertical bandsaw machine in which workpieces to be cut are fed by hydraulic means into a bandsaw blade which is driven at a fixed position is illustrated. The vertical bandsaw machine comprises a base 101 provided with a column 102 on which a frame 103 is supported. A bandsaw blade 104 is trained around a driving wheel 105, supported in base 101, and a driven wheel 106, supported in frame 103. Driving wheel 105 is adapted to be driven by any suitable means which are apparent to one skilled in the art and which do not constitute, per se, a part of the present invention.
A sliding worktable 107 is appropriately mounted for sliding movement on base 101. Worktable 107 is provided with a suitable clamp for clamping a workpiece W. Worktable 107 supports a bracket 108 which is connected with the piston rod 109 of a hydraulic cylinder or motor 110 which is rigidly mounted in base 101. A controlling means 111 is connected to hydraulic cylinder 110. Controlling means 111 is the same as the hydraulic circuit which is illustrated in FIG. 2 of the drawings, and is accordingly not illustrated in further detail in FIGS. 4A and 4B.
In operation, a workpiece W is clamped in worktable 107 and driving wheel 105 is driven to continuously drive bandsaw blade 104. Controlling means 111, which includes a flow control valve means, is operated to alternately increase and decrease the flow of hydraulic fluid to hydraulic cylinder or motor 110, while continuously displacing piston rod 109 and bracket 108. Workable 107, carrying workpiece W, is thereby continuously fed, alternately fast and slow, into bandsaw blade 104.
Referring now to FIG. 5, an additional embodiment of a vertical bandsaw machine is illustrated. The embodiment of FIG. 5 is similar to the embodiment of FIGS. 4A and 4B in that the bandsaw blade, while being rotated for cutting, is held at a fixed position while the workpiece is moved into the bandsaw blade to effect cutting. Accordingly, similar components of the bandsaw machine of FIG. 5 will not be described in greater detail. The bandsaw machine on FIG. 5 differs from the embodiment illustrated in FIGS. 4A and 4B in that the workable is fed by a screw means, instead of by a hydraulic motor. Sliding worktable 120, which is mounted for sliding movement similar to the embodiment of FIGS. 4A and 4B, supports a bracket 121. A nut 122 is mounted in bracket 121 and mates with a lead screw 123 which is rigidly fixed to the base of the bandsaw machine. Lead screw 123 is connected at one end through a pulley 124 to a servo motor 125, which is mounted on the base of the bandsaw machine and arranged so as to rotate and drive the lead screw 123.
In accordance with the present invention, the lead screw 123 is continuously driven alternately fast and slow by the servo motor 125 so that a workpiece clamped to worktable 120 is continuously fed alternately fast and slow into the bandsaw blade. Thus, it will be understood that the vertical bandsaw machine of FIG. 5 performs cutting action in the same manner as the vertical bandsaw machine of the embodiment of FIGS. 4A and 4B.
Although a preferred form of the present invention has been illustrated and described, it should be understood that the device is capable of modification by one skilled in the art without departing from the principles of the invention. Accordingly, the scope of the invention is to be limited only by the claim appended hereto. | A method and apparatus for controlling the cutting of bandsaw machines includes continuous feeding of the bandsaw blade relative to the workpiece by alternating the speed at which the bandsaw blade is fed relative to the workpiece between fast and slow, so that the bandsaw blade is continuously periodically fed relative to the workpiece alternately fast and slow. In a first embodiment, the bandsaw blade is fed into the workpiece and a continuously operating control motor is used to control a flow valve to alternate the speed at which the bandsaw blade is fed into the workpiece. In a second embodiment, the workpiece is fed into the bandsaw blade and a continuously operating control motor is used to control a flow control valve to alternate the speed at which the workpiece is fed into the bandsaw blade. In a third embodiment, the bandsaw blade is fed into the workpiece and a continuously operating servo motor is used to drive a lead screw to alternate the speed at which the bandsaw blade is fed into the workpiece. In a fourth embodiment, the workpiece is fed into the bandsaw blade and a servo motor is continuously used to drive a lead screw to alternate the speed at which the workpiece is fed into the bandsaw blade. | 8 |
[0001] The present invention concerns a method according to the preamble of claim 1 and a device according to the preamble of claim 7 .
THE PRIOR ART
[0002] In association with either one of the bleaching and the delignification of cellulose pulp in bleaching lines, the pulp passes between different treatment steps in which the pulp is subjected to bleaching or the delignifying effect of various treatment chemicals. The treatment typically alternates between alkaline and acidic treatment steps in which typical sequences may be of ECF type (elemental chlorine-free, Cl, in which chlorine dioxide may be used) such as O-D-E-D-E-D, O-D-PO or sequences of TCF-type (totally chlorine-free) such as O-Z-E-P. Other bleaching steps, such as Pa steps and H steps may be used.
[0003] The treatment steps may take place either at medium consistency (8-16%) or at high consistency (≧20-30%), but it is vitally important to wash out after each treatment step degradation products and lignin precipitated during the treatment step and to reduce to a minimum the remaining fraction of fluid, since the latter will otherwise lead to an increased requirement for pH-adjusting chemicals for the subsequent treatment steps and transfer of precipitated lignin and other degradation products, which subsequent step generally takes place at a completely different pH.
[0004] Simple vacuum filters with dewatering drums that are partially (typically 20%-40% of the drum) immersed in the pulp suspension that is to be dewatered were used in certain older types of washing step after a bleaching step or a delignification step. In these vacuum filters, a bed of pulp forms spontaneously against the outer surface of the drum under the influence of a negative pressure in the interior of the drum, and the pulp bed is drawn up from the pulp suspension by the rotation of the drum and is scraped off with a scraper on the side of the drum that is moving downwards. A consistency higher than 8-14% is generally never achieved for the pulp bed that has been dewatered, due to the limited degree of dewatering that is achieved, and the dewatered pulp that is scraped of can be readily formed to a slurry with a low consistency again in a subsequent collecting trough. The technique used here is a lower degree of dewatering followed by slurry formation with a cleaner filtrate, and this takes place in a series of vacuum filters in order to achieve the required washing effect. For this reason, it is attempted to achieve as high a degree of dewatering as possible before the dewatered pulp is again formed to a slurry with cleaner filtrate before the subsequent treatment stage.
[0005] A dominating washing machine on the market for bleaching lines is the conventional dewatering press, or thickening press, in which pulp is applied to at least one outer surface of the dewatering drum and subsequently passes a nip between the drums and acquires a consistency of 20-30% or greater after the nip. A practical upper limit lies at 35-40%, where a higher degree of dryness cannot be achieved without affecting the strength properties of the fibres negatively. A representative washing press of this type is disclosed in the patent U.S. Pat. No. 6,521,094.
[0006] The dewatered mat of cellulose pulp that is fed out from the washing machine's nip must first be shredded due to the high degree of dewatering, which shredding takes place in a shredder screw.
[0007] The purpose of the shredder screw has been exclusively to break up the mat of dewatered cellulose pulp and feed it onwards to equipment in which the cellulose pulp is rediluted to a consistency that makes it possible to pump it onwards to the next treatment step.
[0008] The redilution thus preferably takes place in association with adjustment of the pH, which after an alkaline wash normally involves the addition of powerful acidifiers, or the addition of acidic return water/filtrate from subsequent process steps, before the subsequent acidic treatment step. These acidic conditions have involved the dilution in general being held well separated from the previous alkaline wash as well as the associated shredder screw, since the alkaline wash can be built from simpler material than that which is normally required for washing machines that resist acidic conditions. Acidic conditions require material that can resist acids, and this is significantly more expensive that other material.
[0009] The pulp on exit from the shredder screw has a very high level of dryness, a consistency of 20-30% or greater, and this means that redilution has been carried out in all installed plants in at least one separate dilution screw arranged after the shredder screw, where the dilution fluid is added during intensive agitation from the dilution screw in order to achieve a suitable homogenous consistency that makes pumping onwards to the next treatment stage possible. The diluted pulp that is achieved after the dilution screw is fed to a stand pipe in the bottom of which a pump is arranged.
[0010] A second alternative for washing is the use of a dewatering screw, in which the cellulose pulp is first diluted and subsequently dewatered in a dewatering screw (of the Thune type or Sudor press type) to a level of dryness that considerably exceeds 20-30%. In this way, what is known as “wash-by-dilution” is achieved. A compacted and well-consolidated dewatered pulp is obtained at the exit from the dewatering screw also in this case. A redilution has been used also in this case after the dewatering screw, with the addition of dilution fluid during intensive agitation from a dilution screw.
[0011] The very high consistency of the pulp after the dewatering press or the dewatering screw has given rise to the belief that dilution to a homogenous medium consistency cannot be achieved unless dilution occurs under the influence of intensive agitation from the dilution screw. A consistency of the pulp of 20-30% or greater is experienced as dry and compacted. It can be mentioned for the sake of comparison that medium-consistency pulp is so compact that it is just about possible to walk on this pulp, when it is at the upper part of the consistency range.
[0012] The use of a dilution screw at this position, however, increases the requirement for energy, it increases investment costs, it raises the requirement for maintenance and it involves a further mechanical treatment of the pulp which has a negative influence on the strength properties of the pulp.
AIM AND PURPOSE OF THE INVENTION
[0013] The present invention is intended to remove the above-mentioned disadvantages and is based on the surprising insight that even if the pulp has been dewatered to give a very high consistency, 20-30% or more, no mechanical agitation at all is required during the dilution provided that the pulp bed has been shredded to give small granules of a suitable size, and provided that the dilution fluid is added evenly over a flow of the freely falling granulated pulp.
[0014] It has surprisingly turned out to be the case that the granulated pulp demonstrates the properties of a sponge, despite its high consistency, and that, provided the dilution fluid is added evenly to a flow of non-tightly packed granulated pulp in freefall, a primary homogenised dilution of the pulp takes place that is fully adequate such that it can subsequently be pumped or led onwards to the following bleaching stage or treatment stage.
[0015] It is sufficient in laboratory experiments with small quantities of well-granulated pulp with a consistency around 30-35% to pour the required amount of fluid to obtain the required consistency into a container with granulated and non-compressed pulp, and the complete mixture has been homogenised to an even consistency after the addition of the fluid totally without mechanical agitation. Observation of the granulated pulp has shown that there lie cavities between the granules, and the fluid rapidly penetrates between the granules through the complete volume of the granules, after which the granules absorb the fluid as sponges.
[0016] This primarily homogenised pulp is fully adequate to be pumped with a subsequent pump, in which a secondary or complementary homogenisation takes place, and these together ensure that the same degree of homogenisation of the pulp can be achieved for the subsequent treatment stage completely without mechanical agitation from a dilution screw. The principal aim of the invention is thus to redilute pulp from a high consistency of 20-30% or higher without the use of a dilution screw and without intensive mechanical agitation, which reduces losses in the strength of the pulp.
[0017] A second aim is to reduce operating costs and maintenance costs for the process equipment in the redilution, since no operation of dilution screw is necessary.
[0018] A further aim is to reduce the investment cost of the process equipment. A reduction of both operating costs and investment costs in the process equipment entails a reduction in the cost of manufacturing bleached pulp to an equivalent degree, and this saving is multiplied by the number of washing machines that are used in the bleaching line. No less than six washing machines are included in an O-D-E-D-E-D sequence, and thus the reduction in costs can be significant.
[0019] Approximately 50 kW is required solely for the operation of one dilution screw, and the investment cost is approximately SEK 500,000 (depending to a certain extent on requirements on materials, i.e. whether it needs to be acid-resistant or not).
[0020] The operating costs per year in an O-D-E-D-E-D bleaching line will be:
6*50 kW*SEK 0.20 (the price for an operator in Sweden)* 24 hours* 350 days (the number of operating days per year, excluding stoppages)=SEK 500,000 SEK per year;
[0021] and the investment cost will be:
6*SEK 500,000=SEK 3,000,000.
[0022] This investment cost at an interest rate of 5% corresponds to an annual expense of SEK 150,000.
[0023] In summary, implementation of the invention involves a total annual saving that approaches SEK 650,000-1,000,000 SEK including maintenance costs and building space (frameworks, etc.) in a bleaching line with a capacity of 1,000 tonnes per day.
[0024] Furthermore, availability of the mill increases since six machines can be removed, each of which has an MTBF (mean time between failure).
[0025] A further aim is to remove a treatment step between the washing machine and the subsequent pumping, which makes possible a more compact mill and opportunities to place the washing machines at a lower height over the ground in the mill. The washing machines are normally placed at a great height over the ground, and the pulp falls downwards after being washed in the washing machine while it passes through various conditioning steps. If one of these conditioning steps (such as the dilution screw) becomes unnecessary, the building height can be reduced, which In turn gives a saving.
[0026] With these aims, the invention is characterised by the characteristics of claim 1 with respect to the method according to the invention, and by the characteristics of claim 7 with respect to the device according to the invention.
DESCRIPTION OF DRAWINGS
[0027] FIG. 1 shows a typical treatment step for the pulp in a reactor with a subsequent washing press according to the prior art;
[0028] FIG. 2 shows part of the system in FIG. 1 (prior art);
[0029] FIG. 3 shows a dilution system according to the invention;
[0030] FIG. 4 shows a detail of FIG. 3 ; and
[0031] FIG. 5 shows a view seen from underneath in FIG. 4 , seen at the level of the section A-A.
[0032] FIG. 6 shows an alternative dilution system according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] FIG. 1 shows a conventional treatment step for cellulose pulp, hereafter denoted “pulp”. The pulp is fed by the pump 1 to a mixer 2 in which necessary treatment chemicals are added. These treatment chemicals can be, for example, oxygen gas, ozone, chlorine dioxide, chlorine, peroxide, pure acid or a suitable alkali for an extraction step, or a mixture of these, and possibly other chemical or additives such as a chelating agent. The pulp is transported after the addition of the necessary chemicals by the mixer 2 to a reactor system 3 , here shown in the form of a single-vessel tower 3 of upwards flow. The reactor system can, however, be constituted by simple pipes or by one or several reactors in series, and possibly with the batchwise addition of chemicals between the towers in those cases In which the bleaching processes are compatible and do not require washing between the towers.
[0034] The treated pulp is fed after treatment in the reactor system 3 to a pulp chute/stand pipe 4 , which establishes the buffer volume and static pressure required, to a pump 5 arranged at the bottom of the pulp chute. The pulp is fed from the pump 5 to a washing machine 7 , shown here in the form of a washing press with two drums 7 a , 7 b . The pulp is applied to the drums, here at the 12 o'clock position, and is led by convergent pulp collectors during the addition of washing fluid (not shown in the drawing) to a final dewatering nip between the drums, from where a mat of dewatered pulp is fed upwards to a shredder screw 8 .
[0035] The drums in FIG. 1 rotate in opposite directions and the pulp mat is dewatered through the outer surface of the drum while the pulp is lead approximately 270° around the circumference of the drum to the nip. The washing press may be preferably equivalent to that revealed by the patent U.S. Pat. No. 6,521,094. Any other type of dewatering press or washing press, however, having a drum or drums, may be used, in which a consistency of 20-30% or higher is achieved, for example a washing press with a single dewatering drum and an opposing roller, or other types of washing press with two dewatering drums.
[0036] The pulp is fed upwards from the nip in the form of a dewatered and compressed mat 20 of cellulose pulp that has been consolidated into large pieces to a shredder screw 8 , the shredding axis of which is arranged to be essentially parallel to the axes of rotation of the drums. A small oblique mounting of a maximum of 5-10° may, for example, be present if a conical shredder screw is used, where the mat is fed to an inlet slit in the outer casing of a conical shredder screw, where the inlet slit lies parallel with the axes of the drums. The fragmented pulp is led after this shredder screw 8 out from an outlet in the casing of the shredder screw in the flow 21 to a dilution screw 30 that is driven by a motor 31 . The dilution screw exposes the pulp to continuous tumbling during the addition of dilution fluid Liq2, and the pulp is subsequently fed to a stand pipe 40 at its finally conditioned consistency. The pulp can subsequently be pumped from the stand pipe 40 to the next treatment step of similar type in the bleaching line.
[0037] FIG. 2 shows another view of a part of the same process in which the shredder screw 8 is oriented in the same direction as the dilution screw 30 . It can be seen more clearly here how the dewatered and compressed mat 20 of pulp that has been consolidated into large pieces is fed into the shredder screw 8 . The shredder screw contains a threaded screw 8 a that is driven by a motor 8 c , and that may also be equipped with a number of beaters 8 b at its outlet, which beaters further whip and break up the shredded pulp. The purpose of the shredder screw is primarily to break into smaller pieces the dewatered and compressed mat 20 of pulp that has been consolidated into large pieces, and it may sometimes be sufficient with one such shredder screw. The beaters 8 b may be arranged on the same shaft as the shredder screw and they provide an extra fragmentation effect, but they are primarily used to hold the outlet from the shredder screw free from the formation of blockages.
[0038] The fragmented flow 21 of pulp particles is fed thereafter to fall under its own weight to the subsequent dilution screw 30 .
[0039] FIG. 3 shows the dilution system according to the invention in a treatment step that is otherwise equivalent to that shown in FIG. 1 . The dewatered web of pulp, which has a consistency of 20-30% or greater, is fed in this case in to the shredder screw 8 in the same way as shown in FIGS. 1 and 2 . However, dilution occurs in the outlet from the shredder screw according to the invention in a significantly simplified manner. It is important that the web or mat 20 of pulp, which maintains a consistency of 20-30% or higher, is first fragmented by the shredder screw such that the mat 20 is granulated to a particle size that Is normally distributed around a mean size that lies in the interval 5-40 mm. This is taken to denote that the fragmented pulp has a particle size that is normally distributed around a maximum size that is less than 40 mm, preferably less than 30 mm, and even more preferably less than 20 mm. It is appropriate that the normal distribution is distributed such that 90-95% of the fragmented pulp lies within ±5 mm of the maximum size, 40-30 or 20 mm, of the fragmented pulp.
[0040] The granulated pulp is then fed out from the outlet of the shredder screw in free fall into a stand pipe 22 connected to the outer casing of the shredder screw at its outlet. The dilution fluid LiqDIL is subsequently added under pressure into the stand pipe through a number of fluid jets preferably arranged around the periphery of the stand pipe and above a level LiqLEV of diluted cellulose pulp established in the stand pipe. Alternatively, some or all of the fluid jets may originate from a central pipe that is located in the flow of the fragmented pieces of pulp that are standing in free fall, and where the fluid jets are directed essentially radially outwards. A certain oblique adjustment may be established, but it is preferable that the jets are directed towards the freely falling flow with an angle of attack of 90°, or within the interval 90°±60° (=30°-155°), such that a certain minimum angle of attack is established. There may be so many fluid jets that an essentially continuous “fluid curtain” is established, or the dilution fluid may be injected into the flow of freely falling fragmented pulp through one or several slits. The important fact is that the dilution fluid is added to the flow at several points and at points at which the granulate is falling freely before it reaches the underlying surface of pulp that has been diluted to its final degree.
[0041] In the embodiment shown in FIG. 3 , the upper connection 22 of the stand pipe to the outer casing of the shredder screw has a smaller diameter than the lower part 40 ′ that lies below. The principle is that the pulp falls under the influence of gravity down through the parts 22 , 40 ′ of the stand pipe, and its lower part 40 ′ is given a larger diameter in order to be able to establish a suitable buffer volume before the pumping with the pump 41 ′ at a given level of pulp LiqLEV in the stand pipe 22 , 40 ′.
[0042] The amount of dilution fluid LiqDIL added establishes a consistency of the cellulose pulp within the range of medium consistency 8-16%, which is a consistency that allows the pulp to be sent onwards using an MC pump. The amount of dilution fluid that is required in order to establish the consistency at which the pulp is subsequently pumped is constituted to more than 75-90% of the fluid that is added at the said nozzles arranged above the level/surface that has been established in the stand pipe. A certain amount of chemicals such as acidifiers/alkali or chelating agents may be added at the bottom of the stand pipe 22 / 40 ′, but the principal dilution takes place with the dilution fluid above the pulp level established in the stand pipe.
[0043] The cellulose pulp at this medium consistency is fed by the pump 41 onwards from the lower end of the stand pipe to subsequent treatment steps for the cellulose pulp.
[0044] The dilution of the pulp from high consistency of 20-30% or greater at the upper part of the stand pipe to a medium consistency of 8-16% before the pumping from the lower part of the stand pipe takes place in this manner exclusively under the influence of the hydrodynamic effect from the addition of the dilution fluid through the said nozzles.
[0045] FIG. 3 and FIG. 4 show an embodiment of the manner in which addition of the dilution fluid can be realised. The dilution fluid is added by a pump to a distribution chamber 60 that is arranged concentrically around the stand pipe 22 . The pump pressurises the fluid to a suitable level, an excess pressure of approximately 0.1-0.8 bar. Alternatively, high-pressure nozzles can be used, which finely distribute the dilution fluid in the form of fanned plumes of fluid, oriented at a suitable angle relative to the vertical, a suitable angle being 30-90°.
[0046] A number of nozzles 62 are arranged at the bottom of the distribution chamber oriented obliquely downwards, in the direction of flow of the granulate, and inwards towards the centre of the flow. The amount of obliqueness in the mounting is appropriately 45±15° relative to the vertical. The oblique orientation downwards is favourable for achieving an ejecting influence on the granulate flow, and for avoiding the risk that the dilution fluid splashes upwards in the stand pipe.
[0047] A number of nozzles, at least four, are arranged around the stand pipe 22 / 40 ′, preferably with equal distances between them. With a stand pipe 22 having a diameter of 800-1,500 mm, it is appropriate that 10 - 40 nozzles are arranged around the periphery of the stand pipe. It is appropriate that the distance between adjacent nozzles be less than 50-300 mm. If high-pressure nozzles with fanned plumes of fluid are used, the nozzles may be arranged with a greater distance between neighbouring nozzles. It is important that the dilution fluid is added evenly around the complete circumference of the flow of granulate and at a sufficiently high pressure in order to penetrate to the centre of the granulate flow. The pressure setting is an engineering adaptation that is based on the nozzles being used, the diameter of the pipe and the rate of flow of fragmented pulp.
[0048] FIG. 6 shows an alternative embodiment of the invention. The difference between the embodiment shown in FIG. 3 and this embodiment is that the dewatering arrangement in this case is a deewatering screw (of Thune type or Sudor type) in which a conical screw 80 a compresses an incoming flow 20 of pulp during dewatering against a surrounding space through a screwed surrounding perforated housing, and in which filtrate 80 b is led away from this space. The driving force for the screw is normally located at its inlet, but the motor 8 c is here shown connected to the outlet of the screw.
[0049] The dewatered and compressed pulp that has been consolidated into large pieces is also in this case fed from the outlet of the screw to a simpler fragmentation arrangement in the form of a number of beaters 8 b that may be located on the same shaft as the conical screw while being located at its outlet. These beaters 8 b whip and break up the pulp that is fed out from the dewatering screw in the form of dewatered and compressed pulp that has been consolidated into large pieces. It Is preferable that these beaters have their own source of power, and that they are driven at a rate of revolution that considerably exceeds the rate of revolution of the screw.
[0050] The fragmented flow 21 of pulp particles is subsequently fed by falling under its own weight to the fall 40 , in the same manner as that shown in FIG. 3 . Furthermore, a second dewatering screw 90 is arranged to receive the diluted pulp suspension at the bottom of the fall 40 . The dewatering screw 90 may be another transport arrangement or another distribution arrangement, such as, for example, a distribution screw in the inlet arrangement to a dewatering press.
[0051] The dilution otherwise functions in the same manner as in the embodiment shown in FIG. 3 , and those parts that are the same have the same reference numerals.
[0052] The invention can be modified in a number of ways within the scope of the claims. The nozzle 62 for the addition of dilution fluid may, for example, be constituted by a simple drilled hole in a thick corrugated sheet, with a minimum thickness of 8-10 mm. However, specially adapted nozzles are preferred, which preferably generate a fan-shaped plume of fluid, in order to ensure optimal penetration of the granulate flow and an even distribution over the complete circumference of the flow. Addition of dilution fluid can also take place at a sufficiently high pressure that the dilution fluid more forms a very finely divided mist in the region that the granulated pulp passes.
[0053] Addition of dilution fluid takes place in the preferred embodiment in association with an increase in the area of the stand pipe 22 to a lower part 40 ′ of the stand pipe having a larger diameter, but it is not necessary that the addition takes place in association with an increase in area. A small amount may also be added at the outlet end of the shredder screw, with the addition flow directed down towards the stand pipe. But the dilution is to take place principally through the hydrodynamic mixing effect from the addition of the dilution fluid into the flow of granulate. | The method and a device is for the dilution of dewatered cellulose pulp that maintains a consistency of 20-30% or greater. By shredding of the pulp to a finely divided dry-granulate, dilution to a homogeneous consistency in the medium consistency range can take place exclusively through hydrodynamic effects from the addition of dilution fluid. The dilution fluid is added to granulate at a position at which granulate is in free fall in a standpipe and above a level Liq LEV of diluted pulp in the standpipe. A number of nozzles are arranged around the periphery of the stand pipe, directed in towards the centre of the stand pipe, obliquely downwards in the direction of fall of the granulate. It is possible through this simplified procedure to avoid completely the conventional dilution screws, and this reduces the investment costs and operating costs, while at the same time unnecessary mechanical influence of the pulp fibres can be avoided. | 3 |
FIELD OF THE INVENTION
[0001] The invention provides an apparatus for use in an irrigation system.
BACKGROUND OF THE INVENTION
[0002] Irrigation systems for plants, flowers, vegetables and other biological systems requiring water provide a continuing or periodic supply of moisture to the plants. Above-ground type irrigation systems include sprinkler systems that distribute water over a generally broad area and often require either the installation of permanent water lines and hardware or require the hardware to adapt to the irrigation needs of various plant configurations. The water distributed from sprinkler-type irrigation systems is directed over a general area and not directed to the roots of a particular plant, requiring use of excessive quantities of water. Alternative ground-based irrigation systems include porous hoses that seep water through the hose wall or that have apertures that emit a stream of water when the hose is under pressure. Such hoses often result in excess water usage and require excessive lengths to meet the irrigation needs of many plants and may result in damage to delicate foliage when placing, removing or relocating the hoses.
[0003] Because of these limitations, drip irrigation systems have been developed in which one or more lines or tubes emanating from an irrigation fluid supply individually terminate at a discharge device, termed an emitter. Dramm et al. disclosed an emitter having an elongated member with multiple internal passages generally in the form of a “T” with one fluid inlet and two lateral fluid discharge outlets, which are located at approximately the longitudinal midpoint of the emitter. (See, U.S. Pat. No. 6,695,231). However, the number, size and placement of the discharge outlets increases the likelihood of clogging the emitter. For example, the placement of the discharge outlets at the midpoint of the emitter can result in the blocking of these discharge outlets when the emitter is inserted into the soil, or plant roots growing into and thereby blocking the discharge outlets. Also, there is a lack in the Dramm emitter of an individual shut-off mechanism, resulting in water and fertilizer waste and damage to plants from over-watering. Emitters that are fabricated out of iron or other metals suffer from oxidation and other corrosive chemical reactions in the presence of water or other liquids or soil, resulting in the leaching of toxic metal compounds into the soil and an unattractive appearance of the emitter. Metal-fabricated emitters are also sensitive to fluctuations in the price and availability of the metals, thereby requiring substantial investments in purchasing and warehousing these metals, and causing insecurity as to the availability of critical components in the fabrication process.
[0004] In view of the foregoing, it would be desirable to provide an emitter for a drip irrigation system that is resistant to clogging by dirt or plant material, where each emitter device can be easily and quickly shut off, preferably with one hand, and easily installed or removed without damaging the plant. It is also desirable to provide an emitter that contains a metal core, giving the emitter a high specific gravity so as to keep the emitter firmly in place, and the metal core is encased in a synthetic cover, providing corrosion resistance, a uniform appearance, and the ability of the manufacturer to substitute core metals based on pricing and availability.
SUMMARY OF THE INVENTION
[0005] In general, aspects of the present invention relate to components of irrigations systems having novel configurations. In one aspect, the invention provides an emitter containing a body portion having an external surface extending between a first end and a second end, a first passage extending in a proximal-distal orientation from the first end towards the second end of the body portion, a second passage extending from the external surface to the first passage, whereby the first passage and second passage are operably linked, an entry portion on the first end of the body portion including an entry opening operably linked to the first passage and a tube end attachment means, and a tube side attachment means disposed on a surface of the external wall. In certain embodiments, the first passage and second passage each have substantially curved surfaces, and the diameter of the second passage is greater than the diameter of the first passage. In other embodiments, the second passage extends radially from the external surface to the first passage, and the second passage is located closer to the first end of the body portion than the second end of the body portion. In other embodiments, the second passage is adjacent to the entry opening. In some embodiments, the tube end attachment means includes at least one external circumferential ridge configured to engage an interior of the tube. In these embodiments, providing an emitter with the second passage forming an outlet for water or other liquids roughly adjacent to the entry opening to which the tube is connected is useful in that the emitter will be placed with the second end in or on the soil, reducing the chance of soil or plant material entering the outlet. The combination of the first passage and the second passage creates an L-shaped passage. At least a section of the body portion has a substantially cylindrical external shape. In a further embodiment, the tube side attachment means contains two wall surfaces projecting away from the body portion, and the wall surfaces are positioned so as to form a channel into which a tube can be retainably placed. Optionally, the wall surfaces are tapered such that the proximal end of each wall surface relative to the first end of the body portion is shorter than the distal end of each wall surface. These tapered wall surfaces reduce the likelihood of snagging the emitter on the plant when the emitter is inserted or removed. In some embodiments, the second end of the body portion is closed. In other embodiments, the distance between the first end and the second end is about fifty millimeters (two inches). In further embodiments, the distance between the first end and the second passage is about twenty millimeters (about three-quarters of an inch) or less. The emitter is optionally formed of a metallic material core surrounded by a synthetic cover, thereby providing corrosion resistance, a uniform appearance, and the ability of the manufacturer to substitute core metals based on pricing and availability. In another embodiment, the center of gravity along a proximal-distal orientation relative to the first and second ends is closer to the second end than the first end.
[0006] In a second aspect, the invention provides an emitter that contains a body portion having an external surface extending between a first end and a second end, a first passage extending in a proximal-distal orientation from the first end towards the second end of the body portion, a second passage extending from the external surface to the first passage, where the first passage and second passage are operably linked, thereby creating an L-shaped passage, an entry portion on the first end of the body portion including an entry opening operably linked to the first passage and a tube end attachment means. In certain embodiments, the first passage and second passage each have substantially circular surfaces, and the diameter of the second passage is greater than the diameter of the first passage. In other embodiments, the second passage extends radially from the external surface to the first passage, and the second passage is located closer to the first end of the body portion than the second end of the body portion.
[0007] In a third aspect, the invention provides an apparatus for a drip irrigation system that includes at least one fluid flow regulation device, at least one elongated member having an internal passage adapted to couple to the flow regulation device, and an emitter that contains a body portion having an external surface extending between a first end and a second end, a first passage extending in a proximal-distal orientation from the first end towards the second end of the body portion, a second passage extending from the external surface to the first passage, where the first passage and second passage are operably linked, an entry portion on the first end of the body portion including an entry opening operably linked to the first passage and a tube end attachment means, and a tube side attachment means disposed on a surface of the external wall. In some embodiments, the elongated member is a flexible, non-porous tube, and the fluid flow regulation device has a means for connection to an irrigation fluid supply source.
[0008] In a fourth aspect, the invention provides a method of irrigating a plant by providing an apparatus for a drip irrigation system that includes at least one fluid flow regulation device, at least one elongated member having an internal passage adapted to couple to the flow regulation device, and an emitter that includes a body portion having an external surface extending between a first end and a second end, a first passage extending in a proximal-distal orientation from the first end towards the second end of the body portion, a second passage extending from the external surface to the first passage, where the first passage and second passage are operably linked, an entry portion on the first end of the body portion containing an entry opening operably linked to the first passage and a tube end attachment means, and a tube side attachment means disposed on a surface of the external wall, and positioning the emitter on or at least partially in a support medium surrounding the plant. The invention also includes a plant irrigated by this method.
[0009] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of aspects of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In the case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting.
DESCRIPTION OF THE DRAWINGS AND FIGURES
[0010] The present invention may be further appreciated with reference to the appended drawing sheets wherein:
[0011] FIG. 1 is a perspective view of an emitter of the present invention.
[0012] FIG. 2 is a perspective view of an emitter of the present invention.
[0013] FIG. 3 is a cross-sectional view of an emitter of the present invention.
[0014] FIG. 4A is a perspective view of an apparatus for a drip irrigation system of the present invention. FIG. 4B is a perspective view of an emitter of the present invention with a tube engaged in the tube side attachment means of the emitter.
[0015] Other objects, features, and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
DETAILED DESCRIPTION OF THE INVENTION
[0016] In some embodiments described herein, the present invention relates generally to a device useful as an emitter for a liquid irrigation system, and an apparatus for a drip irrigation system. The emitter is useful in distributing fluids (e.g., water, liquid fertilizer, etc.) to one or more plants or other biological systems.
[0017] Referring to FIG. 1 , an emitter 10 is shown. In one embodiment the emitter 10 has a body portion 11 including a first end 12 and a second end 14 . At the first end 12 is an entry portion having an opening, termed a fluid inlet 16 , having a generally circular shape for receiving irrigation fluids from an elongated member such as a flexible tube 18 . The emitter 10 includes a tube attachment means for connecting the emitter 10 to the tube 18 . For example, the tube attachment means may include one or more circumferential ridges at first end 12 are shown schematically as barbs 20 , improve the retention of an end 22 of the flexible tube 18 . In operational linkage with the fluid inlet 16 is a first passage, termed the inlet passage 24 that has two ends and extends from the fluid inlet 16 towards the second end 14 of the emitter. The inlet passage 24 generally extends in a linear direction from the fluid inlet 16 and has a generally circular shape roughly the same diameter as fluid inlet 16 . Preferably, the inlet passage 24 extends from the first end 12 in a proximal-distal orientation towards the second end 14 of the body portion 11 . The inlet passage 24 terminates at a second passage, termed the outlet passage 26 , that extends to the inlet passage 24 from an exterior surface 28 of the emitter 10 . In certain embodiments the body portion 11 of the emitter is roughly cylindrically shaped and the inlet passage 24 encompasses the center of this cylindrical shape. The outlet passage 26 may extend from the inlet passage in a radial direction. Inlet passage 24 and outlet passage 26 may be formed in the shape of an “L”. In alternative embodiments, the inlet and outlet passages may be provided in any geometric shape that results in a liquid flow pattern suitable for providing a fluid discharge path. Preferably, the inlet passage 24 and outlet passage 26 each have substantially curved surfaces, such that each passage is defined by a substantially cylindrical geometry. Advantageously, when the inlet passage 24 and outlet passage 26 are cylindrically shaped, the diameter of the outlet passage 26 is greater than the diameter of the inlet passage 24 , such that the flow rate of a liquid traveling from the fluid inlet 16 through the inlet passage 24 is greater than the flow rate of a liquid traveling through the outlet passage 26 . Reduction of the flow rate of the fluid entering the plant or soil is useful to minimize the potential for displacement of the soil or other medium surrounding the plant.
[0018] It is advantageous for the emitter device of the invention to be easily and quickly shut off, preferably with one hand. The emitter shown in FIG. 1 contains a tube side attachment means 30 disposed on the exterior surface 28 . The tube side attachment means includes two wall surfaces 32 that project away from the body portion 11 . These wall surfaces 32 are positioned so as to form a channel 34 into which tube 18 can be retainably placed. An exemplary depiction of a closed-off drip irrigation system apparatus is shown in FIG. 4B , in which a portion of the tube 18 has been inserted between the wall surfaces 32 and into channel 34 . The wall surfaces 32 are optionally curved to assist in retention of the tube 18 . The wall surfaces 32 are tapered such that the height of the proximal end 36 of each wall surface 32 relative to the first end 12 of the body portion 11 proximal end is less than the height of the distal end 38 of each wall surface 32 . An advantage of having tapered wall surfaces 32 is that the wall surfaces are less likely to catch or snag part of the plant when the emitter 10 is removed. For the same reason it is advantageous that the first end 12 of the emitter is tapered and similarly smaller than the second end 14 .
[0019] Generally, the emitter is placed on or at least partially in a support medium surrounding the plant to provide a drip irrigation source of fluid. Usually the support medium is soil or other nutritive solid material. Other support mediums known in the art, such as sand, gels and other semi-solid materials, are also included in the present invention. Further, in the practice of hydroponic agriculture the emitter can be placed in or near the fluid surrounding the plant, for the addition of water, liquid fertilizer, and the like. Alternatively, the emitter 10 is placed within the foliage of the plant. In some embodiments, the emitter 10 is weighted to improve its retention at the irrigation location of the plant. For example, the emitter 10 may contain an inner material, termed a core 40 , surrounded by an exterior material, termed a cover 42 . In certain embodiments, the cover 42 is a synthetic material such as a plastic. Often, the core 40 is a metallic or other material with a higher density than the cover 42 , and is positioned such that the center of gravity of the emitter is closer to the second end than the first end of the emitter. In embodiments where the core 40 is a metal such as iron that corrodes (e.g., oxidizes) in the presence of water or other liquids, the cover 42 prevents such corrosion. The material used to form the core 40 is completely obscured by the cover 42 , so that this material can be substituted with another suitable material based on market conditions.
[0020] The emitter 10 has a length (as measured from the first to the second end) of between about five (5) and one hundred (100) millimeters, such as between about 10 and 80 millimeters, 20 and 70 millimeters, or 40-60 millimeters. In one embodiment the emitter is about 55.5 millimeters in length. The emitter 10 at a region distal to the side attachment means has an external diameter of about 9.5 millimeters excluding the side attachment means, and an external diameter of about 14 millimeters including the side attachment means.
[0021] The emitter 10 may have any suitable weight to correspond to the resiliency of the tube 18 and to allow installation in, or removal from, a plant without damaging or injuring the plant. For example, the emitter 10 weighs between one and over fifty grams, such as between 5-25 grams, or 10 and 15 grams. In a specific embodiment the emitter 10 weighs about eleven grams.
[0022] Referring to FIG. 4A , the emitter of the invention can be provided as part of an apparatus for a drip irrigation system. This apparatus contains an emitter 10 , at least one fluid flow regulation device 44 , and at least one elongated member having an internal passage adapted to couple to the flow regulation device, depicted in FIG. 4A as a flexible non-porous tube 18 . The fluid flow regulation device 44 , which is also termed a pressure compensator, a pressure compensating emitter or a dripper, is operably linked to a irrigation fluid supply source, such as a water tank or supply pipe, and is useful to provide a constant flow rate of water or other liquid, including under circumstances wherein the pressure of the fluid entering from the supply source into the fluid flow regulation device 44 is variable over time. For example, the fluid flow regulation device 44 is capable of receiving water and other fluids at high pressure and delivering the same fluid at a lower pressure. The fluid flow regulation device 44 is capable of operating at pressures of below 5 pounds per square inch (psi) to above 55 psi. The fluid flow regulation device preferably includes a means for connection to an irrigation fluid supply source, such as a container, reservoir, or the like.
[0023] The apparatus for a drip irrigation system is useful for irrigating plants, flowers, trees, shrubs, vegetables, and other biological systems. The apparatus is positioned such that the flow regulation device is operably linked to a source of water or other fluid. The emitter of the apparatus is positioned on or at least partially in a support medium surrounding the plant. For example, if the plant is surrounded by soil, the emitter is placed with the second end inserted into the soil near the plant. As described herein, in some embodiments the emitter is about fifty millimeters in length, as measured from the first end to the second end, and the distance between the first end and the second passage is about twenty millimeters or less. For example, the distance between the first end and the center of the second passage is 12 millimeters. In such a configuration a portion of the emitter body can be placed in the soil, thereby increasing the security of the placement of the emitter and decreasing the movement of the emitter, which could result in damage to the plant. Such a configuration also decreases the risk of clogging the second passage with soil.
[0024] The present invention is not limited to the particular methodologies, protocols, constructs, formulae and reagents described but further include those known to the skilled artisan. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention.
[0025] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the invention. All publications and patents mentioned herein are incorporated herein by reference. | The current invention provides a emitter with an internal passage for a drip irrigation system that delivers an irrigation fluid such as water from a fluid source to one or more plants. The emitter is capable of being operably attached to a tube or other conduit of an irrigation fluid. Optionally, the emitter includes a means for reversibly attaching a side portion of a tube to the emitter. | 8 |
FIELD OF THE INVENTION
The present invention relates generally to product packages such as food packages, and more particularly, to a product package incorporating a napkin as a part thereof.
BACKGROUND OF THE INVENTION
For many years, products such as snack foods have been individually packaged by conventional form, fill, and seal packaging machines in the snack food industry. Snack foods are many, and include items such as candy bars, sweet rolls honey buns, doughnuts, etc. Improved packaging technology over the years has ensured both the freshness and purity of food items enclosed therein. For example, human contact/handling of food items has been almost completely eliminated by the automated packaging machinery of recent years.
Typically, individually packaged snacks today are packaged in flexible films that are fed from rolls of flexible sheet material to form tubes for receiving individual product servings being delivered at high speeds. The individual servings are then separated by heat-sealing mechanisms that seal the individual packages in the longitudinal and transverse (top and bottom) positions. The individual packages are subsequently packaged in bulk and stored/shipped for subsequent sale and consumption.
Individually packaged snack food items are usually consumed by persons who are away from home and on-the-go. As such, these consumers typically do not have napkins or other wiping items available while eating the snack items. Unfortunately, some snack items such as honey buns, cinnamon buns, doughnuts and other pastries have glazing or sticky coatings. As a result, consumers get “sticky” fingers and lack any means to wipe them or wash them.
SUMMARY OF THE INVENTION
The present invention is directed to a combination product package and napkin for a snack food that satisfies the need for a readily available napkin or towelette for persons consuming snack food items. While this specification describes the invention with respect to food items, it is apparent that it may be applicable to non-food items that may be similarly packaged; but use of the product therein makes the availability of the napkin desirable.
Each of the embodiments described herein is formed from a singular sheet of film having a main portion bounded by a seal area or margin which extends along the opposed ends, down one side, and along a path parallel to, but spaced apart from, the other side. In two of the embodiments a flap, having a napkin attached thereto, extends outwardly from at least one of the opposed edges of the sheet.
In general, the invention is directed to a combination product package (snack food)/napkin including a product wrapper and a napkin. The product package is a flexible film wrapper around the product in sealing relation thereto. The napkin is affixed or attached in some manner to the outside of the wrapper, yet is covered so that it is protected from external contaminants, etc. Preferably, a tear strip is provided along one edge of the package to facilitate opening.
In one embodiment, the wrapper is formed from a sheet of flexible film such as oriented polypropylene, cellophane, or the like. When formed, the package has a front wall, a rear wall, and a width. As is conventional in the packaging arts, a longitudinal seal is formed on the rear wall and extends between the opposed ends of the package. Transverse seals extend are formed at the opposed ends of the package to complete the packaging of the snack item. A flap formed as an extension of the flexible film extends outwardly from the longitudinal seal on the rear wall of the package. In the embodiment described herein, the flap extends lengthwise between the opposed ends of the package and is sealed or otherwise attached at each end by the transverse seals at the opposed ends. Thus, the flap has an inner surface area overlying a portion of the rear wall of the package and a free edge forming a pocket between the flap and the package. A napkin is affixed to at least some portion of the inner surface of the flap so that a consumer can insert his or her fingers between the rear wall and the inner surface of the flap to wipe them clean of residue from the snack.
In a second embodiment, the wrapper is similarly formed from a sheet of flexible film, having a front wall, a rear wall, and a width, with similar longitudinal and transverse seals. As is conventional in the packaging arts, a longitudinal seal is formed on the rear wall and extends between the opposed ends of the package. Transverse seals extend are formed at the opposed ends of the package to complete the packaging of the snack item. A pair of overlying flaps extend outwardly from the longitudinal seal and lengthwise between the opposed ends. The opposed flaps that are formed as extensions of the flexible film extend outwardly from the longitudinal seal on the rear wall of the package, having facing inner surfaces and free outer edges. A napkin is affixed to at least some portion of the inner surface of each of the overlying flaps so that a consumer can spread open the opposed flaps and wipe his or her fingers on the exposed napkin.
In yet another embodiment, the wrapper is similarly formed of the same flexible sheet material, encapsulating a napkin or towelette that is affixed by bonding or adhesive to either the front or rear wall of the package so that a consumer may easily access the napkin.
In still another embodiment of the package, the flexible film sheet is extended lengthwise of the wrapper so that a separate compartment may be formed for containing the napkin apart from the product compartment.
These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment in combination with the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of one embodiment of the package of the present invention;
FIG. 2 is a rear perspective view of the package of FIG. 1 ;
FIG. 3 is a plan view of the inner surface of the sheet of flexible film suitable for use in forming the package of FIGS. 1 and 2 ;
FIG. 4 is a schematic cross-sectional view of the package of FIGS. 1 and 2 ;
FIG. 5 is a rear perspective view of a second embodiment of the package of the present invention;
FIG. 6 is a plan view of the inner surface of the sheet of flexible film suitable for use in forming the package of FIG. 5 ;
FIG. 7 is a schematic cross-sectional view of the package of FIG. 4 ;
FIG. 8 is a front perspective view of a third embodiment of the package of the present invention; and
FIG. 9 is a front perspective view of a fourth embodiment of the flexible package of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the Figures in general, and to FIGS. 1 through 4 in particular, one embodiment of the present invention is directed to combination product/napkin package. The package, shown generally as 100 , comprises a flexible product wrapper 110 and a napkin 150 . Again, it should be understood that while a food package is specifically described herein, other product packages that can be commercialized with a napkin are within the scope of the present invention.
The product wrapper 110 is formed from a generally rectangular singular sheet 109 of flexible film having opposed ends 111 that define the length of the package, and opposed sides 113 . The sheet 109 includes a main portion 108 and a marginal area 107 which forms the seals after the package is formed. The package formed therefrom includes a front wall 114 , a rear wall 115 , opposed sides edge 119 , and a width. To seal the product within the package wrapper 110 , a longitudinal seal 116 extends lengthwise between the opposed ends 111 to enclose the film 109 around the product, such as a honey bun or other food item. Transverse seals 117 extend across the width of the package 100 at the opposed ends 111 to completely seal the product within the package 100 . A tear strip 121 is formed by conventional and well known construction along one side to provide easy access to the contents without destroying the seal 116 for reasons to become apparent.
In the first embodiment shown in FIGS. 1 through 4 , the continuous sheet 109 of flexible film is formed from oriented polypropylene, cellophane, polyester, or the like film material. As will be appreciated, the continuous sheet forming the wrapper 110 is cut from a large roll during the actual assembly line packaging process. Such packaging assembly equipment is available from any number of packaging machine manufacturers, such as Tevopharm from Bosch of the Netherlands. Again, the sheet 109 contains a main portion 108 and a marginal area seal area 107 which extends along the opposed ends 111 , down one side 113 , and along a path parallel to, but spaced apart from, the other side 113 , which defines a flap 118 as later described. The manner in which the film wraps around and encloses and seals the food product is conventional and will not be repeated herein.
In the embodiment shown in FIGS. 1 through 4 , the sheet 109 of the flexible film 110 further comprises flap 118 that extends outwardly from the longitudinal seal 116 to a free edge 118 a and lengthwise between the opposed ends 111 . As will be appreciated, the flexible sheet 109 is dimensioned so that the flap 118 is part of the continuous sheet which extends beyond the seal area 108 . The flap 118 is joined or bounded at the opposed ends 111 by the transverse seals 117 . As will also be appreciated, the longitudinal and transverse seals 116 , 117 formed in marginal areas 130 may be either heat sealed by the conventional packaging machines or may be cold sealed with a suitable adhesive applied to the film, as illustrated in FIG. 3 . The manner of forming the seals is well known in the art and not critical to the present invention.
As best shown in FIGS. 2 and 4 , a napkin 150 is affixed at the ends thereof to the inwardly facing surface of the flap 118 so that the napkin 150 is not directly exposed to outer contact or contaminants from normal handling of the package 100 . The napkin 150 may be formed of any suitable paper, or fabric, stock suitable for napkins and similar sanitary items. Alternatively, the napkin 150 may be in the form of a towelette, as desired; however, the material of the napkin 150 may be varied depending upon the type of snack item enclosed in the package 100 , etc. Further, while the napkin 150 in the embodiment shown in FIG. 3 extends the entire length of the flap 118 , and is affixed at the ends only, it may be affixed to some other portion of the inner surface of the flap 118 and is affixed at the ends only. The napkin 150 may be adhesively bonded to the film, or alternatively, the napkin 150 may embody an adhesive within the composition of the napkin 150 that can be sprayed or layered over the film to form the napkin 150 .
With the flap 118 and napkin 150 formed as shown in FIGS. 1 through 4 , and because of the free edge 118 a , the napkin 150 is easily accessible for a consumer of the snack to insert their fingers beneath the flap without having to break any of the seals 116 , 117 of the package 100 . To facilitate opening of the package 100 itself, a tear strip 121 is preferably formed in the wrapper 110 so that it is conveniently located when the wrapper 110 is folded around the snack. As shown in the Figures, the tear strip 121 formed according to conventional techniques is located adjacent one of the opposed side edges of the folded wrapper 110 .
Turning now to FIGS. 5 through 7 , a second embodiment 200 of the combination package of the present invention is shown. This embodiment of the combination package 200 comprises the same flexible film in a continuous sheet as the first embodiment 100 described above. The sheet 209 includes a main portion 208 and a marginal seal area 207 . The sheet 209 of the flexible film 210 further comprises a pair of flaps 218 , 219 that extend outwardly from the longitudinal seal 216 to a free edges 218 a , 219 a and lengthwise between the opposed ends 211 . As will be appreciated, the flexible sheet 209 is dimensioned so that the flaps 218 , 219 are part of the continuous sheet which extends beyond the seal area 108 . The package 200 also comprises the same longitudinal 216 and transverse 217 seals as described above to enclose and seal the snack within the wrapper 210 . As best seen in FIG. 5 , however, a pair of flaps 218 , 219 extend outwardly from the longitudinal seal 216 when the wrapper 210 is folded around the product. The flaps 218 , 219 comprise opposite ends of the unfolded wrapper 210 . The flaps 218 , 219 extend lengthwise between the opposed ends 211 of the package 200 , but are not necessarily joined by the transverse seals 217 at opposed ends 211 of the package 200 . As shown in FIGS. 5 and 7 , the flaps 218 , 219 may extend outwardly generally perpendicular to the rear wall 215 , or alternatively be folded downwardly against the rear wall 215 . At least some portion of the inwardly, overlying surfaces of the flaps 218 , 219 e each have a napkin 250 a , 250 b affixed thereto. As the flaps 218 , 219 have free ends 218 a , 219 a , a consumer may readily spread the two flaps 218 , 219 apart to access a larger napkin surface for wiping of the fingers. Again, a tear strip 221 is located adjacent one of the opposed side edges 219 of the folded wrapper 210 is provided.
Turning now to FIG. 8 , a third embodiment of the combination package 300 is illustrated. The package 300 of flexible film is constructed similar to the embodiments described above with longitudinal 316 and transverse seals 317 which enclose and seal the product within the package 300 . Unlike the previous embodiments, the napkin 350 of this embodiment is encapsulated in a separate packet 360 formed of the same or similar flexible sheet material of which the wrapper 310 is formed. As will be appreciated, there are numerous ways in which a packet 360 may be separately formed with a folded napkin sealed therein. The packet 360 may be heat or cold sealed to either the front wall 314 or rear wall 315 , as desired for the particular product package. Further, as the flexible film is transparent, indicia 355 , such as the product name or price, may be printed or colored on the napkin 350 so that it is outwardly visible to a consumer. In this manner, the napkin 350 serves multiple purposes. Alternatively, in lieu of a separate packet 360 for encapsulating the napkin, a layer of flexible film may be laminated over the top of the napkin 350 that is placed directly adjacent the front wall 314 or rear wall 315 surface.
Turning lastly to FIG. 9 , yet another embodiment of the package 500 of the present invention is shown. This package of flexible film is constructed from a singular sheet of flexible film with the same type of longitudinal seal 516 described above. In this embodiment, however, the sheet may have a greater length that the sheets described above so that a separate compartment 520 may be formed for containing a napkin 550 . As shown in the Figure, transverse seals 517 enclose and seal the product, and a third transverse seal 518 encloses and seals a napkin 550 in a separate compartment. Tear strips 521 and/or 522 may be incorporated into the flexible sheet material to facilitate opening of the product compartment and/or the napkin compartment.
It should be recognized that the preferred embodiment described above is exemplary only. Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims. | A combination product/napkin package is provided. The combination package includes a product wrapper and a napkin. The product wrapper comprises a sheet of flexible film that is foldable around the product and has edges sealable around a periphery to enclose and seal the product therein. The napkin is affixed to the wrapper at a position outside the sealed product. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a device for retaining a bobbin case member against rotation, and more particularly to a device for use in a horizontally fully rotatable shuttle for restraining the bobbin case member thereof from rotation and for releasing an upper thread free of resistance.
With bobbin case member retaining devices heretofore known for use in horizontally fully rotatable shuttles, a retainer is adapted to act on two portions of the bobbin case member alternately to assure smooth passage of the upper thread. Since the bobbin case member is retained at alternately changing locations in the case of such devices, the bobbin case member is liable to backlash, consequently making a noise and leading to reduced sewing efficiency.
Additionally the parts must be finished with high dimensional accuracy so that the retainer will act on the bobbin case member at two portions thereof alternately accurately for the retention of the shuttle member. This entails an increase in manufacturing cost.
SUMMARY OF THE INVENTION
The main object of the invention is to eliminate such drawbacks of conventional devices and to provide a device for use in a horizontally fully rotatable shuttle for restraining the bobbin case member thereof from rotation, the device including a retaining member adapted to act on only one portion of the inner shuttle member and to permit smooth passage of an upper thread.
To fulfill this object, the present invention provides a device for use in a horizontally fully rotatable shuttle for retaining a bobbin case member against rotation, characterized in that a retaining member is adapted to contact one poriotn of the bobbin case member for retaining the inner shuttle member, one of the contact faces of the bobbin case member and the retaining member being partly formed with a recess, the retaining member being reciprocally movable along the contact face of the bobbin case member to prevent the rotation of the bobbin case member and permit release of an upper thread free of resistance.
According to a preferred embodiment of the invention, the recess is formed in the contact face of the retaining member.
According to another preferred embodiment of the invention, the recess is formed in the contact face of the bobbin case member.
Other objects and features of the invention will become more apparent from the following detailed description with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view showing a horizontally fully rotatable shuttle incorporating a retaining device embodying the invention;
FIG. 2 is a front view of the same;
FIG. 3 is a perspective view showing the components of the retaining device;
FIGS. 4 to 6 are plan views showing the operation of the retaining device and the passage of an upper thread; and
FIG. 7 is a plan view showing another retaining device embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First with reference to FIGS. 1 to 6, an embodiment of the invention will be described.
As seen in FIGS. 1 and 2, an outer shuttle member 2 is mounted on a base 1 by a shaft 3. The shaft 3 carries a cam 5 thereon. A bobbin case member 6 is rotatably fitted in the outer shuttle member 2.
The bobbin case member 6 is formed in its upper portion with a circular arc contact face, namely a side wall A, extending from its outer periphery inward. A thread passing large-diameter portion D is formed at the terminal end of the side wall A.
An inner shuttle retaining member 7 has a contact face, namely, an acting side face B opposed to the side wall A of the bobbin case member 6 and is attached to a retainer support plate 8 with two screws 9. The support plate 8 is integral with a lever 10 and is supported by a pivot 11 on the base 1 for a circular arc motion.
The lever 10 is biased into contact with the cam 5 at all times by the action of a coil spring 12. The rotation of the cam 5 pivotally moves the retainer support plate 8, causing the retaining member 7 on the support plate 8 to perform a circular arc motion in timed relation to the rotation of the outer shuttle member 2. The center of the circular arc motion coincides with the center of the circular arc form of the side wall A of the bobbin case member 6.
Since the acting side face B of the retaining member 7 is positioned on a circular arc having the same radius as the circular arc of the side wall A of the bobbin case member 6, the acting side face B of the retaining member 7 performs a circular arc motion along the circular arc side wall A of the bobbin case member 6. The acting side face B is formed with a recess C approximately at the midportion of the area thereof over which the face B contacts the side wall A of the bobbin case member 6.
The retaining member 6 performs the circular arc motion over such a range that when the member 7 has turned counterclockwise in FIG. 1 to its limit position, the forward end of the acting side face B is still in contact with the side wall A inside the outer periphery of the bobbin case member 6. During the circular arc motion of the retaining member 7, therefore, the member 7 is in contact, at some portion of its acting side face B, with the side wall A of the bobbin case member 6 at all times to restrain the inner shuttle member 6 from rotation.
When the shuttle is in operation, an edge 4 formed in the outer shuttle member 2 captures the upper thread and forms a loop 13, which advances along the outer periphery of the bobbin case member 6 with the counterclockwise rotation of the outer shuttle member 2. When the outer shuttle member 2 reaches the position shown in FIG. 4 during its counterclockwise rotation, the rotation of the cam 5 turns the retaining member 7 counterclockwise and brings the recess C in the member 7 outward from the side wall A of the bobbin case member 6. The upper thread loop 13 enters the recess C.
As the outer shuttle member 2 further rotates from the position of FIG. 4, the rotation of the cam 5 moves the recess C clockwise from the position of FIG. 4 to the position shown in FIG. 5. In this state, the loop 13 in the recess C of the retaining member 7 advances along the side wall A of the inner shuttle member 6 with the turn of the recess C.
As the outer shuttle member 2 further rotates from the position of FIG. 5, the rotation of the cam 5 moves the recess C from the position of FIG. 5 further clockwise to the position shown in FIG. 6, where the recess C is positioned inwardly of the side wall A of the bobbin case member 6 to form a space between the retaining member 7 and the large-diameter portion D. The loop 13 is now released from the recess through the space.
With a further rotation of the outer shuttle member 2, the retaining member 7 returns to the position shown in FIG. 4 and thereafter continues the same circular arc motion as above.
FIG. 7 shows another embodiment in which the recess is otherwise provided. A recess C' is formed approximately at the midportion of the contact face, namely side wall A', of the bobbin case member 6'. The retaining member 7' has a contact face, namely an acting side face B', of reduced width and a thread-passing small-diameter portion E on the left side of the side face.
The embodiment of the above construction operates in the following manner.
When the retaining member 7' has turned clockwise in FIG. 7 to its rightward limit position, the acting side face B' of the retaining member 7' is positioned on the right side of the recess C' in the side wall A' of the bobbin case member 6', with the result that the small-diameter portion E of the retaining member 7' forms a clearance which extends from outside to the recess C' for smoothly passing an upper thread loop 13 therethrough. After the loop 13 had entered the recess C' through the clearance, the retaining member 7' turns counterclockwise, shifting the acting side face B' of the member 7' to the left side of the recess C' in the bobbin case member 6' to open the recess C' toward the direction in which the loop 13 is to be passed. Thus the loop 13 is smoothly released from the recess C'.
With a further rotation of the outer shuttle member, the retaining member 7' continues the above circular arc motion with the acting side face B' in contact with the side wall A' of the inner shuttle member 6' at all times.
In this way, the circular arc motion of the acting side face of the retaining member along the contact face of the bobbin case member, namely, the side wall thereof assures smooth passage of the upper thread loop. During the circular arc motion, the acting side face of the retaining member is in contact with the same side face of the inner shuttle member, namely, the side wall thereof to prevent the rotation of the inner shuttle member.
With the construction described above in detail, the device of this invention for use in a horizontally fully rotatable shuttle for retaining the inner shuttle member against rotation has the following remarkable advantages.
Since the bobbin case member is restrained from rotation by being engaged at the same portion thereof at all times, the inner shuttle member can be retained in a constant condition. The inner shuttle member is therefore free of any backlash, assures stable sewing performance and gives off no noise.
Whereas the conventional retaining device requires high dimensional accuracy because the bobbin case member is acted on at two portions for retention, the invention has overcome this problem and ensures a reduction in manufacturing cost. | A device for preventing the rotation of the bobbin case member of a horizontally fully rotatable shuttle comprises a retaining member adapted to contact one portion of the inner shuttle member for retaining the bobbin case member against rotation. One of the contact faces of the bobbin case member and the retaining member is partly formed with a recess. The retaining member is reciprocally movable along the contact face of the bobbin case member to prevent the rotation of the shuttle member and permit release of an upper thread free of resistance. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for preparing a propargylic alcohol catalyzed by 2-morpholinoisobornane-10-thiol (MITH).
[0003] 2. Description of Related Art
[0004] Chiral propargylic alcohols are versatile building blocks for the synthesis of optically active pharmaceutical ingredients and natural products. The following Table 1 exemplifies some applications of propargylic alcohols.
[0000]
TABLE 1
Entry
Starting block
Synthetic product
Remark
1
Chondrillin, an anticancer natural product
2
Pesticide
3
(−)-Chlorothricolide, an aglycone of chlorothricin which is an antibiotic capable of inhibiting biosynthesis of cholesterol
4
(+)-Spirolaxine, isolated from fungi, being able to reduce the amount of cholesterol, and toxic to endothelial and tumor cells
5
(−)-Scopadulcic Acid A, extracted from Scrophularia L ., being helpful to digestion and protective to digestive system
[0005] Among the several efficient procedures that have been developed, such as Ti-mediated reactions, there is a particular emphasis on the asymmetric nucleophilic addition of Zn-alkynylides to carbonyl compounds to prepare enantioenriched propargylic alcohols, which offer the advantages of the low-toxicity of zinc metal and the wide functional group tolerance of organozinc reagents. In literature reports describing the asymmetric addition of Zn-alkynylides to aldehydes, preparing the corresponding propargylic alcohols in high enantiomeric excess (ee) usually requires high ligand loadings. Thus, it is desirable to develop a method for preparing propargylic alcohols with an effective chiral mediator that promotes the enantioselective alkynylation of aldehydes at lower ligand loading.
SUMMARY OF THE INVENTION
[0006] The object of the present invention is to provide a method for preparing a propargylic alcohol catalyzed by 2-morpholinoisobornane-10-thiol (MITH), comprising reacting R 1 CHO with R 2 CCH in the presence of R 3 ZnR 4 and MITH, wherein each of R 1 , R 2 , R 3 , and R 4 , independently, is optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, alkylsilyl, heterocycloalkyl, heterocycloalkenyl, aryl, aryloxy, or heteroaryl. The method of the present invention can provide compounds of formulas (I) and (II) when (−)-2-exo-morpholinoisobornane-10-thiol((−)-MITH) and (+)-2-endo-morpholinoisobornane-10-thiol((+)-MITH) are used as the chiral ligands, respectively.
[0000]
[0007] Preferably, each of R 1 and R 2 , independently, is C 1-30 alkyl optionally substituted by one or more of halogen, nitro, cyano, 5-14 membered heteroaryl, C 6-14 aryl, C 6-14 aryloxy, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl, CO 2 —C 2-30 alkenyl, and C 1-30 alkylsilyloxy; (CH 2 ) i R a ; C 2-30 alkenyl optionally substituted by one or more of halogen, nitro, cyano, 5-14 membered heteroaryl, C 6-14 aryl, C 6-14 aryloxy, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; (CH 2 ) r CH═CH(CH 2 ) k R a ; C 5-14 cycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; C 5-14 cycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; 5-14 membered heterocycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; 5-14 membered heterocycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; C 6-14 aryl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, C 6-14 aryloxy, CO 2 —C 1-30 alkyl, and CO 2 —C 2-30 alkenyl; C 1-30 alkylsilyl optionally substituted by one or more of halogen, nitro, and cyano; or 5-14 membered heteroaryl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl, and CO 2 —C 2-30 alkenyl; and each of R 3 and R 4 independently is C 1-30 alkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl, CO 2 —C 2-30 alkenyl, C 6-14 aryl and 5-14 membered heteroaryl; C 2-30 alkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl, CO 2 —C 2-30 alkenyl, C 6-14 aryl and C 5-14 heteroaryl; C 5-14 cycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; C 5-14 cycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; 5-14 membered heterocycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; 5-14 membered heterocycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; C 6-14 aryl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; or 5-14 membered heteroaryl optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl, wherein R a is C 6-14 aryl substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; C 1-30 alkylsilane optionally substituted by one or more of halogen, nitro, cyano, C 1-30 alkoxy, CO 2 —C 1-30 alkyl, and CO 2 —C 2-30 alkenyl; or 5-14 membered heteroaryl substituted by one or more of halogen, nitro, cyano, C 1-30 alkyl, C 2-30 alkenyl, C 1-30 alkoxy, C 1-30 haloalkyl, CO 2 —C 1-30 alkyl and CO 2 —C 2-30 alkenyl; i is an integer of 1 to 30; and each of r and k independently is an integer of 0 to 30.
[0008] More preferably, each of R 1 and R 2 , independently, is C 1-16 alkyl optionally substituted by one or more of halogen, nitro, cyano, 5-14 membered heteroaryl, C 6-14 aryl, C 6-14 aryloxy, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl, CO 2 —C 2-16 alkenyl, and C 1-16 alkylsilyloxy; (CH 2 ) i R a ; C 2-16 alkenyl optionally substituted by one or more of halogen, nitro, cyano, 5-14 membered heteroaryl, C 6-14 aryl, C 6-14 aryloxy, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; (CH 2 ) r CH═CH(CH 2 ) k R a ; C 5-14 cycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; C 5-14 cycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 1-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; 5-14 membered heterocycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; 5-14 membered heterocycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; C 6-14 aryl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, C 6-14 aryloxy, CO 2 —C 1-16 alkyl, and CO 2 —C 2-16 alkenyl; C 1-16 alkylsilyl optionally substituted by one or more of halogen, nitro, and cyano; or 5-14 membered heteroaryl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl, and CO 2 —C 2-16 alkenyl; and each of R 3 and R 4 independently is C 1-16 alkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl, CO 2 —C 2-16 alkenyl, C 6-14 aryl and 5-14 membered heteroaryl; C 2-16 alkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl, CO 2 —C 2-16 alkenyl, C 6-14 aryl and C 5-14 heteroaryl; C 5-14 cycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; C 5-14 cycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; 5-14 membered heterocycloalkyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; 5-14 membered heterocycloalkenyl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; C 6-14 aryl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; or 5-14 membered heteroaryl optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl, wherein R a is C 6-14 aryl substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-46 alkenyl; C 1-16 alkylsilane optionally substituted by one or more of halogen, nitro, cyano, C 1-16 alkoxy, CO 2 —C 1-16 alkyl, and CO 2 —C 2-16 alkenyl; or 5-14 membered heteroaryl substituted by one or more of halogen, nitro, cyano, C 1-16 alkyl, C 2-16 alkenyl, C 1-16 alkoxy, C 1-16 haloalkyl, CO 2 —C 1-16 alkyl and CO 2 —C 2-16 alkenyl; i is an integer of 1 to 16; and each of r and k independently is an integer of 0 to 16.
[0009] In one aspect of the method, R 2 is C 6-14 aryl optionally substituted by one or more of halogen, C 1-16 haloalkyl, and C 1-16 alkoxy, and R 1 is (CH 2 ) i R a , in which R a is C 6-14 aryl and i is an integer of 1 to 5.
[0010] In another aspect of the method, R 2 is C 6-14 aryl optionally substituted by one or more of halogen, C 1-16 haloalkyl, and C 1-16 alkoxy, and R 1 is C 6-14 aryl optionally substituted by one or more of halogen, C 1-16 haloalkyl, and C 1-16 alkoxy.
[0011] In still another aspect of the method, R 2 is C 6-14 aryl optionally substituted by one or more of halogen, C 1-16 haloalkyl, and C 1-16 alkoxy, and R 1 is (CH 2 ) r CH═CH(CH 2 ) k R a , in which R a is C 6-14 aryl, and r and k respectively are 1 and 0.
[0012] In further another aspect of the method, R 2 is C 6-14 aryl optionally substituted by one or more of halogen, C 1-16 haloalkyl, and C 1-16 alkoxy, and R 1 is C 2-16 alkenyl optionally substituted by one or more of C 6-14 aryl and C 1-16 alkyl.
[0013] In yet another aspect of the method, R 2 is C 1-16 alkyl, and R 1 is C 6-14 aryl.
[0014] In the method of the present invention, a solvent used can be selected from a group consisting of toluene, hexane, hexane-tetrahydrofuran, toluene-dichloromethane, toluene-dioxane, toluene-diethyl ether, and toluene-tetrahydrofuran. Preferably, the mixture of toluene-tetrahydrofuran is used as the solvent. In this regard, a volume ratio of toluene to tetrahydrofuran can be in a range from 0.5 to 10. Preferably, the volume ratio thereof is in a range from 3 to 9.
[0015] In the method of the present invention, a molar ratio of R 3 ZnR 4 to R 2 CCH can be in a range from 0.25 to 4. Preferably, the molar ratio of R 3 ZnR 4 to R 2 CCH is in a range from 0.5 to 2. Besides, R 2 CCH and R 3 ZnR 4 can be respectively used in an amount of 1 to 8 equivalents based on R 1 CHO.
[0016] In the method of the present invention, R 2 CCH is reacted first with R 3 ZnR 4 and then with R 1 CHO. In other words, it is necessary to react R 2 CCH with R 3 ZnR 4 for a period of time so as to afford zinc acetylides, and then to proceed with the reaction between zinc acetylides and R 1 CHO to give propargylic alcohols. Preferably, a temperature of the reaction with R 3 ZnR 4 is controlled in a range from 10° C. to 70° C., and a temperature of the reaction with R 1 CHO is controlled in a range from −30° C. to 40° C.
[0017] In regard to a used amount of MITH, 0.1˜10 mol % based on R 2 CCH is preferable. Besides, (−)-2-exo-morpholinoisobornane-10-thiol((−)-MITH) can be used as MITH in the method of the present invention. In this case, S-form propargylic alcohols may be prepared in the majority. In the other hand, if (+)-2-endo-morpholinoisobornane-10-thiol((+)-MITH) is used as MITH, R-form propargylic alcohols may be prepared in the majority.
[0018] Referring to a used amount of R 2 CCH and R 3 ZnR 4 , 1 to 8 equivalents based on R 1 CHO are preferable, respectively.
[0019] The term “alkyl” refers to a straight or branched hydrocarbon. Examples of alkyl include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and t-butyl.
[0020] The term “alkenyl” refers to a straight or branched hydrocarbon containing one or more double bonds. Examples of alkenyl, but are not limited to, include ethenyl, propenyl, allyl, and 1,4-butadienyl.
[0021] The term “cycloalkyl” refers to a saturated hydrocarbon ring system. Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.
[0022] The term “cycloalkenyl” refers to a non-aromatic hydrocarbon ring system having one or more double bonds. Examples of cycloalkenyl include, but are not limited to, cyclopentenyl, cyclohexenyl, and cycloheptenyl.
[0023] The term “heterocycloalkyl” refers to a saturated hydrocarbon ring system having at least one ring heteroatom (e.g., N, O, S or Se). Examples of heterocycloalkyl include, but are not limited to, 4-tetrahydropyranyl.
[0024] The term “heterocycloalkenyl” refers to a non-aromatic hydrocarbon ring system having at least one ring heteroatom (e.g., N, O, S or Se) and at least one ring double bond. Examples of heterocycloalkenyl include, but are not limited to, pyranyl.
[0025] The term “aryl” refers to an aromatic ring system, which may be a 6-carbon monocyclic, 10-carbon bicyclic, 14-carbon tricyclic aromatic ring system. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, and anthracenyl.
[0026] The term “heteroaryl” refers to an aromatic ring system having one or more heteroatoms (such as O, N, S, or Se), which may be a 5 monocyclic, 8-12 membered bicyclic, or 11-14 membered tricyclic aromatic ring system having one or more heteroatoms. Examples of heteroaryl groups include pyridyl, furyl, imidazolyl, benzimidazolyl, pyrimidinyl, thienyl, quinolinyl, indolyl, and thiazolyl.
[0027] The term “alkylsilyl” refers to
[0000]
[0000] in which each of R x , R y , and R z is alkyl, independently.
[0028] The term “aryloxy” refers to “—O-aryl”, and the term “alkoxy” refers to “—O-alkyl”. Besides, the term “alkylsilyloxy” refers to
[0000]
[0029] The above-mentioned alkyl, alkenyl, cycloalkyl, cycloalkenyl, heterocycloalkyl, heterocycloalkenyl, alkylsilyl, aryloxy, alkoxy, alkylsilyloxy, aryl and heteroaryl include both substituted and unsubstituted moieties. The term “substituted” refers to one or more substituents (which may be the same or different), each replacing a hydrogen atom. Examples of substituents include, but are not limited to, halogen (such as F, Cl, Br or I), hydroxyl, amino, alkylamino, arylamino, dialkylamino, diarylamino, cyano, nitro, mercapto, carbonyl, carbamido, carbamyl, carboxyl, thioureido, thiocyanato, sulfoamido, alkyl, alkenyl, alkoxy, haloalkyl (i.e. alkyl substituted by one or more halogen atoms), aryl, heteroaryl, cyclyl, heterocyclyl, CO 2 -alkyl and CO 2 -alkenyl. Among these above-mentioned substituents, alkyl, alkenyl, alkoxy, aryl, heteroaryl, cyclyl, and heterocyclyl are optionally further substituted with, for example, alkyl, alkenyl, alkoxy, haloalkyl, aryl, heteroaryl, halogen, hydroxyl, amino, mercapto, cyano, nitro, CO 2 -alkyl or CO 2 -alkenyl.
[0030] 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
[0031] None.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Examples I-1 to I-4
Trial Preparation of (1S)-1,3-diphenyl-prop-2-yn-1-ol (Compound 3)
[0032] Initially, the preparation of zinc acetylide from phenylacetylene 2 and dimethylzinc was examined for the method of the present invention. In accordance with the following Scheme I and the reaction conditions listed in Table I, in the presence of ligand 1 ((−)-2-exo-morpholinoisobornane-10-thiol((−)-MITH), 10 mol %), deprotonation of compound 2 at 70° C. or room temperature in toluene, hexane, or a mixture of toluene-tetrahydrofuran (TOL-THF) followed by the addition of benzaldehyde at −30° C. or 0° C., gave alkynylation product 3.
[0000]
[0000]
TABLE I
Condition 1
Condition
3
4a
Me 2 Zn
2
Temp
Time
Temp
Time
Yield a
ee b
Yield c
Example
(equiv)
(equiv)
Solvent
(° C.)
(h)
(° C.)
(h)
(%)
(%)
(%)
I-1 d
6
7
Toluene
70
2.5
−30
24
66
39
<5
I-2
3
3
Hexane
rt
0.5
0
13
37
68
43
I-3
3
3
Toluene
rt
0.5
0
13
39
62
40
I-4
3
3
TOL-THF e
rt
2
0
28
80
81
ND f
a Isolated yield after column chromatography
b Determination by chiral HPLC.
c Yield determined by crude 1 H NMR.
d The reaction was conducted in 0.125M.
e TOL-THF = toluene/THF = 1.5:1 (v/v).
f Not detected by 1 H NMR.
[0033] With reference to Table I, Compound 3 was obtained predominantly in Example I-1, albeit, with a modest yield and low enantiomeric excess (ee). In addition, although deprotonation at ambient temperature in either toluene or hexane led to unsatisfactory yields, and the methylated adduct 4a was obtained as the major product (Examples I-2 and I-3), preparation of Compound 3 was still achieved. Regarding the results shown in Table I, a better yield with higher ee in which no methylation product was observed (Example I-4) was obtained in a mixed TOL-THF solvent system. (1S)-1,3-Diphenyl-prop-2-yn-1-ol (Compound 3)
[0034] A colorless oil. [α] D 27 −2.4 (c 1.2, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.62-7.60 (m, 2H), 7.48-7.45 (m, 2H), 7.42-7.29 (m, 2H), 5.68 (d, J=6.0 Hz, 1H), 2.32 (d, J=6.0 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 140.6 (C), 131.6 (CH×2), 128.5 (CH×2), 128.4 (CH), 128.2 (CH), 128.2 (CH×2), 126.6 (CH×2), 122.3 (C), 88.8 (C), 86.5 (C), 64.9 (CH); IR (neat) 3365, 3062, 3032, 2872, 2229, 1955, 1885, 1809, 1749, 1598, 1490, 1455, 1031, 757, 692 cm −1 ; HRMS calculated for C 15 H 12 O 208.0888, found 208.0882. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =10.7 min (7.0%), 19.6 min (93.0%), 86% ee.
Examples II-1 to II-7
Optimization of the Reagent Equivalents
[0035] The equivalents of zinc acetylide were subsequently optimized to achieve a better enantioselectivity with the toluene-THF (1.5:1) mixed solvent system according to Scheme II and the parameters of Table II.
[0000]
[0000]
TABLE II
3
4
Example
R
x
y
Time (h)
Yield a (%)
ee b (%)
yield c (%)
II-1
Me
1.5
1.5
36
93
70
ND
II-2
Me
2
2
36
98
69
ND
II-3
Me
4
4
28
85
82
ND
II-4
Me
8
8
36
94
81
ND
II-5
Me
4
8
21
91
80
ND
II-6
Me
4
2
48
85
81
ND
II-7
Et
4
4
22
80
79
19
a Isolated yield after column chromatography
b Determination by chiral HPLC.
c Yield determined by crude 1 H NMR. ND: not detected by 1 H NMR.
[0036] In accordance with the results of Table II, the reaction gave better ee when more than 4 equiv of organozincs were used (Examples II-1 and II-2 vs Examples II-3 to II-7). Although it was reported that a 1:1 mixture of alkynyl and dialkylzinc gave the propargylic alcohols in higher ee, adducts with comparable ee's were observed in these cases under different ratios of dimethylzinc to phenylacetylene (Examples II-3, II-5, and II-6). Alkylation product 4b was obtained when dimethylzinc was substituted with diethylzinc (Example II-7). Accordingly, 4 equiv of methylalkynylzinc for economical concern were applied for further optimization of solvents (Example II-3).
Examples III-1 to III-8
Optimization of the Solvent System
[0037] Over re-examination of the solvent effect was first focused on the role of tetrahydrofuran. After the zinc acetylide was prepared in TOL-THF (1.5:1), the solvents were removed and the addition reaction was performed in toluene since the ether solvent was considered to promote the background reaction. The reaction accorded with Scheme III and the parameters of Table III.
[0000]
[0000]
TABLE III
3
4
Time
Yield b
ee c
yield d
Example
Solvent a
(h)
(%)
(%)
(%)
III-1
Toluene
21
82
8
ND
III-2 e
HEX-THF (1.5:1)
38
90
79
ND
III-3
TOL-DCM (1.5:1)
24
61
64
17
III-4
TOL-DOX (1.5:1)
28
93
74
ND
III-5
TOL-DEE (1.5:1)
28
83
49
12
III-6
TOL-THF (1:2)
96
74
76
ND
III-7
TOL-THF (3:1)
24
94
83
ND
III-8
TOL-THF (9:1)
22
94
77
5
a Solvent abbreviations: TOL—toluene; THF—tetrahydrofuran; HEX—hexane; DCM—dichloromethane; DOX—dioxane; and DEE—diethyl ether
b Isolated yield after column chromatography.
c Determined by chiral HPLC.
d Yield determined by crude 1 H NMR; ND: not detected by 1 H NMR.
e Me 2 Zn (0.7M in hexane) was used; the reaction was conducted in 0.10M with respect to PhCHO.
[0038] In accordance with the results shown in Table III, the absence of tetrahydrofuran in the system delivered quite low ee (Table III, Example III-1 vs Table II, Example II-3). Changing the reaction medium from TOL-THF to HEX-THF was not beneficial to the ee and yield (Example III-2). Using other solvents in place of tetrahydrofuran with toluene gave no better results (Examples III-3 to III-5). Thus, co-solvent mixtures of toluene and tetrahydrofuran with different ratios were tested. A ratio of 3:1 was found to be a better solvent system for the asymmetric addition of phenylethynyl zinc to benzaldehyde, and (1S)-1,3-diphenylprop-2-yn-1-ol 3 was isolated in 94% yield and 83% ee (Example III-7).
Examples VI-1 to VI-8
Optimization of Temperature and Ligand Loadings
[0039] Reactions with PhCHO in different amounts of the ligand 1 at varied temperatures for various periods of time were performed according to Scheme VI and the parameters of Table VI.
[0000]
[0000]
TABLE VI
Example
1 (mol %)
Temp (h)
Time (h)
Yield a (%)
ee b (%)
VI-1
10
rt
6
91
76
VI-2
10
10
16
99
79
VI-3
10
10
24
91
84
VI-4
10
−20
24
75
87
VI-5
10
−30
72
61
90
VI-6
5
−20
42
73
86
VI-7
2.5
−20
48
61
84
VI-8
1
−20
72
73
51
a Isolated yield after column chromatography; methylation product was observed in <5% yield by crude 1 H NMR in all cases
b Determined by chiral HPLC.
[0040] As the results shown in Table VI, conducting the reactions at low temperature enhanced the enantioselectivities (Table VI, Examples VI-1 to VI-5) with the best result of 87% ee along with 75% yield (Example VI-4). A better enantioselectivity (90% ee) was obtained at −30° C. (Example VI-5), but the yield was low and a longer reaction time was necessary. However, as the ligand loading decreased to 2.5 mol %, a slightly deteriorated enantioinduction was observed. In general, 87-84% ee's were observed through 10-2.5 mol % of ligand 1 at −20° C. (Examples VI-4 and VI-6 to VI-8).
Examples V-1 to V-14
Optimization of Additive Addition Based on 2.5 mol % of Ligand 1
[0041] After obtaining good enantioselectivity in the alkynylation of benzaldehyde with only 2.5 mol % of ligand 1 in the abovementioned Example, the attention was then turned to the effects of additives. According to Scheme V and Table V, additives such as isopropanol (Examples V-1 to V-6) and alkyl borates (Examples V-7 to V-10) were investigated to improve the asymmetric induction because they have been reported to accelerate similar catalytic organozinc reactions, and added.
[0000]
[0000]
TABLE V
Example
TOL-THF
Additive a
Yield b (%)
ee c (%)
V-1
3:1
2.5 mol % i-PrOH
61
65
V-2
3:1
5 mol % i-PrOH
58
62
V-3
3:1
10 mol % i-PrOH
63
76
V-4
3:1
25 mol % i-PrOH
62
74
V-5
3:1
50 mol % i-PrOH
66
72
V-6
3:1
100 mol % i-PrOH
55
67
V-7
3:1
10 mol % B(OEt) 3
67
82
V-8
3:1
10 mol % B(Oi-Pr) 3
52
87
V-9
3:1
10 mol % B(Ot-Bu) 3
55
87
V-10 d
3:1
10 mol % B(Ot- Bu) 3
70
79
V-11
4:1
—
59
87
V-12
5:1
—
68
86
V-13
7:1
—
61
85
V-14
9:1
—
55
83
a Additives were added to the reaction mixture after step 1
b Isolated yield after column chromatography; methylation product was observed in <5% yield under crude 1H NMR in all cases.
c Determined by chiral HPLC.
d 8 equiv of alkyne were used.
[0042] Based on the results of Table V, the addition of isopropanol as well as a variety of borates in catalytic to stoichiometric amounts showed no improvement in the ee of the adduct. Nevertheless, perhaps the TOL-THF solvent system was not suitable for the addition of additives in the reaction, and thus the change of the solvent system might enable the addition of the additives to afford the aforesaid improvement. Besides, the ratio of the mixed solvent system was examined again at −20° C. (Examples V-11 to V-14), and it was found that a slightly lower percentage of THF in the co-solvent system could enhance the yield without a loss of ee (Example V-12).
Examples VI-1 to VI-15
Asymmetric Alkynylation of Various Aldehydes Catalyzed by 2.5 mol % of Ligand 1
[0043] The scope of this catalytic system was investigated to include a variety of aldehydes according to Scheme VI and the parameters of Table VI. The detailed steps of the reactions are described as follows: A flame-dried 10-mL flask containing (−)-MITH (6.4 mg, 0.025 mmol, 2.5 mol %) was filled with argon. The flask was added sequentially tetrahedronfuran (667 μL), dimethylzinc (3.3 mL, 4 mmol, 1.2 M in toluene) and phenylacetylene (439 μL, 4 mmol). The mixture was stirred at ambient temperature for two hours before the system was cooled to −20° C. The mixture was stirred at −20° C. for 10 minutes, followed by the addition of the aldehyde (1 mmol). The reaction mixture was workup after 48 hours by the addition of saturated aq. NH 4 Cl. The mixture was diluted with 1 N aq. HCl (20 mL), and was extracted with dichloromethane (20 mL×3). The organic extracts were combined, dried over anhydrous Na 2 SO 4 and concentrated to afford the crude product, which was purified on column chromatography to give the corresponding propargylic alcohol. The ee value was determined by HPLC on a chiral stationary phase.
[0000]
[0000]
TABLE VI
Examples
R 1
R 2
Compound
Time (h)
Yield a (%)
ee b (%)
VI-1
4-Tol
Ph
(5a)
72
70
86
VI-2
3-Tol
Ph
(5b)
72
88
85
VI-3
2-Tol
Ph
(5c)
72
79
86
VI-4
4-Cl—Ph
Ph
(5d)
48
80
86
VI-5
3-Cl—Ph
Ph
(5e)
48
82
86
VI-6
2-Cl—Ph
Ph
(5f)
48
79
83
VI-7
4-MeO—Ph
Ph
(5g)
72
27 c
80
VI-8
4-CF3—Ph
Ph
(5h)
48
84
87
VI-9
Ph
(5i)
48
41
61
VI-10
Ph
(5j)
48
21 d
71
VI-11
PhCH2CH2
Ph
(5k)
48
69
49
VI-12
Ph
4-CF3—Ph
(5l)
48
46
84
VI-13
Ph
4-MeO—Ph
(5m)
48
55
76
VI-14
Ph
4-Cl—Ph
(5n)
48
15
66
VI-15
Ph
n-Bu
(5o)
48
15
75
a Isolated yield after column chromatography, and methylation product was observed in <5% yield in crude 1H NMR in all cases.
b Determination by chiral HPLC.
c The aldehyde was recovered in 68%.
d The aldehyde was recovered in 59%.
e The aldehyde used was cinnamaldehyde.
f The aldehyde used was α-Me-cinnamaldehyde.
[0044] In the cases of substituted benzaldehydes bearing diverse functional groups on the para-, meta-, and ortho-positions, asymmetric alkynylation gave the corresponding propargylic alcohols with 80-87% ee (Examples VI-1 to VI-8). Addition to cinnamaldehyde provided a lower ee (61% ee) of the adduct (Example VI-9), while in the case of the α-substituted analogues, higher ee (71% ee) was observed (Example VI-10). Zinc alkynylides bearing substituents were also utilized, and the corresponding propargylic alcohols were obtained in 66-84% ee, although with unsatisfactory yields (15-55%) (Examples VI-12 to VI-15).
3-Phenyl-1-p-tolyl-prop-2-yn-1-ol (5a)
[0045] A white solid (mp. 58-62° C.). [α] D 27 −5.2 (c 1.2, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.50-7.43 (m, 4H), 7.32-7.27 (m, 3H), 7.20 (d, J=8.0 Hz, 2H), 5.64 (d, J=6.0 Hz, 1H), 2.36 (s, 3H), 2.21 (d, J=6.0 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 137.9 (C), 137.7 (C), 131.6 (CH×2), 129.1 (CH×2), 128.3 (CH), 128.1 (CH×2), 126.6 (CH×2), 122.4 (C), 89.0 (C), 86.3 (C), 64.6 (CH), 21.0 (CH 3 ); IR (neat) 3369, 3053, 3024, 2921, 2864, 2228, 1949, 1904, 1803, 1597, 1489, 1178, 1031, 962, 757, 691 cm −1 ; HRMS calculated for C 16 H 14 O 222.1045, found 222.1049. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =8.5 min (7.0%), 17.4 min (93.0%), 86% ee.
3-Phenyl-1-m-tolyl-prop-2-yn-1-ol (5b)
[0046] A colorless, viscous oil. [α] D 27 −5.8 (c 1.3, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.48-7.44 (m, 2H), 7.41-7.39 (m, 3H), 7.33-7.24 (m, 4H), 7.16-7.14 (m, 2H), 5.64 (d, J=6.2 Hz, 1H), 2.38 (s, 3H), 2.24 (d, J=6.2 Hz, 11-1); 13 C NMR (100 MHz, CDCl 3 ): δ 140.5 (C), 138.1 (C), 131.6 (CH×2), 128.9 (CH), 128.4 (CH), 128.3 (CH), 128.1 (CH×2), 127.3 (CH), 123.7 (CH), 122.4 (C), 89.0 (C), 86.2 (C), 64.7 (CH), 21.2 (CH 3 ); IR (neat) 3368, 3054, 3023, 2920, 2865, 2230, 1951, 1883, 1801, 1607, 1598, 1490, 1032, 757, 691 cm −1 ; HRMS calculated for C 16 H 14 O 222.1045, found 222.1049. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =9.7 min (7.6%), 23.3 min (92.4%), 85% ee.
3-Phenyl-1-o-tolyl-prop-2-yn-1-ol (5c)
[0047] A colorless, viscous oil. [α] D 27 +12.2 (c 1.2, CHCl 3 ); NMR (400 MHz, CDCl 3 ): δ 7.74-7.70 (m, 1H), 7.47-7.42 (m, 2H), 7.32-7.26 (m, 3H), 7.26-7.18 (m, 3H), 5.83 (d, J=5.6 Hz, 1H), 2.49 (s, 3H), 2.18 (d, J=5.6 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 138.3 (C), 135.8 (C), 131.6 (CH×2), 130.6 (CH), 128.3 (CH), 128.2 (CH), 128.1 (CH×2), 126.5 (CH), 126.1 (CH), 122.4 (C), 88.6 (C), 86.2 (C), 62.7 (CH), 18.9 (CH 3 ); IR (neat) 3367, 3062, 3023, 2955, 2923, 2862, 2229, 1953, 1886, 1809, 1598, 1489, 1177, 1034, 961, 756, 691 cm −1 ; HRMS calculated for C 16 H 14 O 222.1045, found 222.1053. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =8.3 min (7.0%), 17.8 min (93.0%), 86% ee.
1-(4-Chloro-phenyl)-3-phenyl-prop-2-yn-1-ol (5d)
[0048] A white solid (mp. 46-48° C.). [α] D 27 −7.9 (c 1.4, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.56-7.53 (m, 2H), 7.46-7.44 (m, 2H), 7.37-7.28 (m, 5H), 5.66 (d, J=6.0 Hz, 1H), 2.30 (d, J=6.0 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 139.0 (C), 134.0 (C), 131.6 (CH×2), 128.6 (CH), 128.6 (CH×2), 128.2 (CH×2), 128.0 (CH×2), 122.0 (C), 88.3 (C), 86.7 (C), 64.1 (CH); IR (neat) 3341, 3055, 2873, 2226, 1949, 1903, 1597, 1488, 1090, 1015, 963, 756, 691 cm −1 ; HRMS calculated for C 15 H 11 ClO 242.0498, found 242.0505. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =8.7 min (6.8%), 27.6 min (93.2%), 86% ee.
1-(3-Chloro-phenyl)-3-phenyl-prop-2-yn-1-ol (5e)
[0049] A colorless, viscous oil. [α] D 27 −14.2 (c 1.5, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.61-7.60 (m, 1H), 7.49-7.45 (m, 3H), 7.33-7.31 (m, 5H), 5.66 (d, J=6.0 Hz, 1H), 2.37-2.35 (m, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 142.4 (C), 134.2 (C), 131.6 (CH×2), 129.7 (CH), 128.6 (CH), 128.2 (CH), 128.2 (CH×2), 126.7 (CH), 124.7 (CH), 121.9 (C), 88.0 (C), 86.8 (C), 64.0 (CH); IR (neat) 3361, 3062, 3021, 2876, 2230, 1945, 1880, 1808, 1759, 1690, 1597, 1489, 1188, 969, 756 cm −1 ; HRMS calculated for C 15 H 11 ClO 242.0498, found 242.0505. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =8.9 min (7.2%), 29.3 min (92.8%), 86% ee.
1-(2-Chloro-phenyl)-3-phenyl-prop-2-yn-1-ol (5f)
[0050] A colorless, viscous oil. [α] D 27 +46.2 (c 1.4, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.83-7.81 (m, 1H), 7.48-7.43 (m, 2H), 7.40-7.38 (m, 1H), 7.35-7.25 (m, 5H), 6.03 (d, J=5.6 Hz, 1H), 2.54 (d, J=5.6 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 137.8 (C), 132.6 (C), 131.7 (CH×2), 129.6 (CH), 129.5 (CH), 128.5 (CH), 128.3 (CH), 128.2 (CH×2), 127.1 (CH), 122.2 (C), 87.6 (C), 86.4 (C), 62.2 (CH); IR (neat) 3371, 3064, 2928, 2854, 2230, 1953, 1923, 1811, 1597, 1574, 1490, 1442, 1032, 756, 691 cm −1 ; HRMS calculated for C 15 H 11 ClO 242.0498, found 242.0499. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 0.5 mL/min, uv 254 nm; t R =8.2 min (8.5%), 9.7 min (91.5%), 83% ee.
1-(4-Methoxy-phenyl)-3-phenyl-prop-2-yn-1-ol (5g)
[0051] A colorless, viscous oil. [α] D 27 −4.2 (c 1.7, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.55-7.51 (m, 2H), 7.47-7.44 (m, 2H), 7.31-7.28 (m, 3H), 6.93-6.89 (m, 2H), 5.63 (d, J=6.0 Hz, 1H), 3.81 (s, 3H), 2.21 (d, J=6.0 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 159.4 (C), 132.9 (C), 131.6 (CH×2), 128.3 (CH), 128.1 (CH×2), 128.0 (CH×2), 122.4 (C), 113.8 (CH×2), 89.1 (C), 86.2 (C), 64.3 (CH), 55.1 (CH 3 ); IR (neat) 3412, 3001, 2956, 2934, 2836, 2228, 1610, 1511, 1251, 1173, 1033, 834, 757, 692 cm −1 ; FIRMS calculated for C 16 H 14 O 2 238.0994, found 238.0998. Chiral HPLC analysis:
[0052] Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =11.9 min (10.1%), 26.4 min (89.9%), 80% ee.
3-Phenyl-1-(4-trifluoromethyl-phenyl)-prop-2-yn-1-ol (5h)
[0053] A colorless, viscous oil. [α] D 27 −6.9 (c 1.4, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.74-7.72 (m, 1H), 7.66-7.64 (m, 1H), 7.47-7.44 (m, 2H), 7.34-7.29 (m, 3H), 5.74 (d, J=5.8 Hz, 1H), 2.39 (d, J=5.8 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 144.3 (C), 131.7 (CH×2), 130.3 (q, J=32 Hz, C), 128.8 (CH), 128.3 (CH×2), 126.9 (CH×2), 125.4 (q, J=3.7 Hz, CH×2), 124.0 (q, J=270 Hz, C), 121.9 (C), 88.0 (C), 87.1 (C), 64.2 (CH); IR (neat) 3346, 3063, 2881, 2230, 1916, 1804, 1620, 1490, 1326, 1167, 1127, 1018, 850, 757, 691 cm −1 ; HRMS calculated for C 16 H 11 F 3 O 276.0762, found 276.0756. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =7.9 min (6.7%), 36.7 min (93.3%), 87% ee.
1,5-Diphenyl-pent-1-en-4-yn-3-ol (5i)
[0054] Colorless crystals (mp. 64-65° C.). [α] D 27 −7.3 (c 0.5, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.50-7.24 (m, 10H), 6.83 (d, J=15.6 Hz, 1H), 6.42-6.36 (m, 1H), 5.29 (d, J=6.0 Hz, 1H), 2.47 (br, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 135.9 (C), 131.6 (CH), 131.6 (CH×2), 128.3 (CH×2), 128.3 (CH), 128.1 (CH×2), 127.9 (CH), 127.8 (CH), 126.6 (CH×2), 122.2 (C), 88.1 (C), 86.1 (C), 63.0 (CH); IR (neat) 3349, 3058, 3028, 2914, 2850, 2225, 1952, 1597, 1489, 1443, 1006, 964, 755, 690 cm −1 ; HRMS calculated for C 17 H 14 O 234.1045, found 234.1045. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.5 mL/min, uv 254 nm; t R =9.6 min (19.7%), 30.9 min (80.3%), 61% ee.
2-Methyl-1,5-diphenyl-pent-1-en-4-yn-3-ol (5j)
[0055] A colorless, viscous oil. [α] D 27 +31.6 (c 1.0, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.47-7.44 (m, 2H), 7.36-7.30 (m, 6H), 7.25-7.21 (m, 2H), 6.75 (s, 1H), 5.14 (d, J=5.6 Hz, 1H), 2.09 (d, J=5.6 Hz, 1H), 2.06 (d, J=1.2 Hz, 3H); 13 C NMR (100 MHz, CDCl 3 ): δ 137.0 (C), 136.7 (C), 131.6 (CH×2), 128.9 (CH×2), 128.4 (CH), 128.2 (CH×2), 128.0 (CH×2), 127.1 (CH), 126.7 (CH), 122.4 (C), 88.1 (C), 86.1 (C), 68.6 (CH), 14.1 (CH 3 ); IR (neat) 3415, 3057, 3025, 2917, 2853, 2200, 1616, 1600, 1489, 1443, 1278, 1062, 756, 691 cm −1 ; HRMS calculated for C 18 H 16 O 248.1201, found 248.1194. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =9.0 min (14.4%), 38.6 min (85.6%), 71% ee.
1,5-Diphenyl-pent-1-yn-3-ol (5k)
[0056] A colorless, viscous oil. [α] D 27 +28.4 (c 1.1, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.43-7.41 (m, 2H), 7.31-7.19 (m, 8H), 4.61-4.56 (m, 1H), 2.85 (t, J=8.0 Hz, 2H), 2.14-2.03 (m, 2H), 1.88 (d, J=5.6 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 141.2 (C), 131.6 (CH×2), 128.4 (CH×2), 128.3 (CH×2), 128.2 (CH), 128.1 (CH×2), 125.8 (CH), 122.5 (C), 89.9 (C), 85.0 (C), 62.0 (CH), 39.1 (CH 2 ), 31.4 (CH 2 ); IR (neat) 3357, 3027, 2925, 2861, 2230, 1948, 1869, 1600, 1490, 1455, 1338, 1042, 756, 691 cm −1 ; HRMS calculated for C 14 H 16 O 236.1201, found 236.1200. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =11.4 min (25.5%), 22.7 min (74.5%), 49% ee.
1-Phenyl-3-(4-trifluoromethyl-phenyl)-prop-2-yn-1-ol (5l)
[0057] Colorless crystals (mp. 50-54° C.). [α] D 27 +1.3 (c 1.1, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.60-7.52 (m, 5H), 7.43-7.33 (m, 4H), 5.71 (br, 1H), 2.45 (br, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 140.2 (C), 131.9 (CH×2), 130.3 (q, J=33 Hz, C), 128.7 (CH×2), 128.6 (CH), 126.7 (CH×2), 126.2 (C), 125.2 (q, J=3.7 Hz, CH×2), 123.7 (q, J=271 Hz, C), 91.2 (C), 85.1 (C), 64.9 (CH); IR (neat) 3337, 3066, 3034, 2923, 2237, 1615, 1324, 1168, 1127, 1068, 1018, 842, 698 cm −1 ; HRMS calculated for C 16 H 11 F 3 O 276.0762, found 276.0752. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =6.9 min (91.9%), 8.3 min (8.1%), 84% ee.
3-(4-Methoxy-phenyl)-1-phenyl-prop-2-yn-1-ol (5m)
[0058] A colorless, viscous oil. [α] D 26 +1.9 (c 1.1, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.61-7.59 (m, 2H), 7.41-7.31 (m, 5H), 6.84-6.82 (m, 2H), 5.66 (d, J=6.0 Hz, 1H), 3.79 (s, 3H), 2.27 (d, J—-6.0 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 159.3 (C), 140.7 (C), 132.9 (CH×2), 128.2 (CH×2), 127.9 (CH), 126.5 (CH×2), 114.3 (C), 113.6 (CH×2), 87.5 (C), 86.1 (C), 64.5 (CH), 54.9 (CH 3 ); IR (neat) 3401, 3033, 2936, 2838, 2226, 2048, 1890, 1606, 1510, 1249, 1032, 832, 701 cm −1 ; HRMS calculated for C 16 H 14 O 2 238.0994, found 238.0995. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =14.0 min (12.1%), 26.6 min (87.9%), 76% ee.
3-(4-Chloro-phenyl)-1-phenyl-prop-2-yn-1-ol (5n)
[0059] A colorless, viscous oil. [α] D 26 +2.6 (c 1.0, CHCl 3 ); NMR (400 MHz, CDCl 3 ): δ 7.59-7.58 (m, 2H), 7.42-7.27 (m, 7H), 5.67 (d, J=6.0 Hz, 1H), 2.31 (d, J=6.0 Hz, 1H); 13 C NMR (100 MHz, CDCl 3 ): δ 140.3 (C), 134.3 (C), 132.8 (CH×2), 128.43 (CH×2), 128.38 (CH×2), 128.2 (CH), 126.5 (CH×2), 120.7 (C), 89.8 (C), 85.2 (C), 64.6 (CH); IR (neat) 3360, 3065, 2875, 2230, 1956, 1901, 1593, 1488, 1190, 1092, 1015, 963, 828 698 cm −1 ; HRMS calculated for C 15 H 11 ClO 242.0498, found 242.0500. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 0.5 mL/min, uv 254 nm; t R =17.3 min (82.8%), 19.0 min (17.2%), 66% ee.
1-Phenyl-hept-2-yn-1-ol (5o)
[0060] A colorless oil. [α] D 25 −18.1 (c 1.3, CHCl 3 ); 1 H NMR (400 MHz, CDCl 3 ): δ 7.54-7.52 (m, 2H), 7.38-7.28 (m, 3H), 5.43 (d, J=5.6 Hz, 1H), 2.26 (td, J=7.2, 2.0 Hz, 2H), 2.13 (d, J=5.6 Hz, 1H), 1.55-1.36 (m, 4H), 0.898 (t, J=7.2 Hz, 3H); 13 C NMR (100 MHz, CDCl 3 ): δ 141.2 (C), 128.3 (CH×2), 127.9 (CH), 126.5 (CH×2), 87.3 (C), 79.9 (C), 64.5 (CH), 30.5 (CH 2 ), 21.8 (CH 2 ), 18.3 (CH 2 ), 13.4 (CH 3 ); IR (neat) 3397, 3031, 2958, 2933, 2873, 2227, 1950, 1884, 1809, 1603, 1494, 1455, 1135, 1002, 698 cm −1 ; HRMS calculated for C 13 H 16 O 188.1201, found 188.1192. Chiral HPLC analysis: Chiralcel OD-H, 2-propanol/hexane (10:90), 1.0 mL/min, uv 254 nm; t R =11.0 min (87.5%), 13.8 min (12.5%), 75% ee.
[0061] In conclusion, the asymmetric addition of zinc alkynylides to aldehydes to give optically active propargylic alcohols catalyzed by ligand 1 has been developed, affording the products in 49-87% ee. Notably, this catalytic system required only 2.5 mol % of the chiral ligand to afford propargylic alcohols derived from substituted benzaldehydes with >80% ee without additional additives. To the best of our knowledge, ligand 1 is the first chiral mediator bearing a β-amino thiol reported to catalyze the alkynylzinc addition reaction with aldehydes.
[0062] Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the invention as hereinafter claimed. | A method for preparing a propargylic alcohol catalyzed by 2-morpholinoisobornane-10-thiol (MITH) is disclosed, which includes reacting R 1 CHO with R 2 CCH in the presence of R 3 ZnR 4 and MITH, wherein each of R 1 , R 2 , R 3 , and R 4 , independently, is optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, alkylsilyl, heterocycloalkyl, heterocycloalkenyl, aryl, aryloxy, or heteroaryl. The method can give enantioenriched propargylic alcohols with good enantioselective at low loading of MITH. | 2 |
TECHNICAL FIELD
The present invention relates to a method and a device capable of measuring a polishing amount of an optical fiber component, such as a component obtained by welding a lens fiber, an end cap, or the like, to an optical fiber tip, while conducting polishing, and more particularly to a method and a device using OCT (Optical Coherence Tomography).
BACKGROUND ART
The polishing amount of an optical fiber component is typically measured by inserting a tip portion of the optical fiber component into a ferrule, polishing with a polishing machine such as disclosed in Patent Literature 1 and 2, and estimating the measured polishing amount of the ferrule as the polishing amount of the optical fiber component.
FIG. 7 is an explanatory drawing illustrating the polishing of an optical fiber component 1 inserted into a ferrule 15 . The optical fiber component is obtained, for example, by welding an end cap 13 to the tip of an optical fiber 10 . The left side of FIG. 7 illustrates a state before the polishing in which the ferrule tip is aligned with the tip of the optical fiber component 1 (tip of the end cap 13 ). Where the polishing is performed as depicted on the right side of FIG. 7 , the measured polishing amount g of the ferrule is taken as the polishing amount of the optical fiber component 1 . The reference numeral 12 in the figure stands for a coating of the optical fiber 10 .
RELATED ART LITERATURE
Patent Literature
Patent Literature 1: Japanese Patent Application Publication No. H11-84141
Patent Literature 2: Japanese Patent Application Publication No. 2005-165016
SUMMARY OF THE INVENTION
Technical Problem
The above-described method requires that the tip portion of the ferrule 15 and the tip portion of the optical fiber component 1 be aligned. This is because where the tip portions are not aligned, the polishing amount of the ferrule 15 becomes different from the polishing amount of the optical fiber component 1 . Accordingly, when the optical fiber component 1 is inserted into the ferrule 15 , the tip portion of the ferrule 15 and the tip portion of the optical fiber component 1 are aligned such that the difference therebetween is, for example, less than 0.5 μm. Such an alignment is a difficult and time-consuming operation.
It is an objective of the present invention to enable direct, accurate and easy real-time measurements of a change in the length (that is, the polishing amount) of an optical fiber component during polishing, regardless of the polishing amount of a ferrule, make it unnecessary to align the tip portion of the ferrule 15 with the tip portion of the fiber component 1 when the optical fiber component is inserted into the ferrule, and increase the operation efficiency.
Solution to Problem
FIG. 1 is an explanatory drawing illustrating the case in which the length (total length) of the optical fiber 10 is measured using the OCT. A light source 2 and a light receiver 6 are connected to one end side of a fiber coupler 3 , which is a brancher of the optical fiber, through an optical fiber 20 and an optical fiber 60 , respectively, and the optical fiber 10 which is to be measured (measuring object) and a reference optical path 4 are connected to the other end side.
The reference optical path 4 has an optical fiber 40 , a lens 41 connected to the tip thereof, a mirror 42 facing the lens 41 , and a mirror moving device 43 . The lens 41 serves for obtaining a substantially parallel beam from the emitted light of the optical fiber 40 . The mirror moving device 43 is an optical path length change unit that moves the mirror 42 attached thereto and changes the optical path length of the reference optical path 4 . The position information on the mirror in the mirror moving device is transmitted to the light receiver 6 .
The light emitted from the light source 2 is branched by the fiber coupler 3 , one branched light enters the optical fiber 10 being measured, and the other branched light enters the reference optical path 4 . The light that has entered the optical fiber 10 being measured is reflected at the tip surface thereof, and the return light thereof reaches the light receiver 6 through the fiber coupler 3 and the optical fiber 60 . The light that has entered the reference optical path 4 passes through the optical fiber 40 and is emitted as a substantially parallel beam from the lens 41 at the tip and reflected by the mirror 42 . The return light thereof reaches the light receiver 6 through the lens 41 , the optical fiber 40 , the fiber coupler 3 , and the optical fiber 60 .
The light receiver 6 receives the return light of the optical fiber 10 being measured and the return light of the reference optical path 4 and detects the length of the optical fiber 10 by the position of the mirror 42 when the two rays of return light interfere (when the light intensity peaks). Since the length of the optical fiber 10 is equal to the length of the reference optical path 4 when the two rays of return light interfere, where the length of the optical fiber 40 and the lens 41 is measured in advance, the length of the optical fiber 10 can be measured by acquiring the position information on the mirror 42 at the time of interference.
When the length (total length) of the same optical fiber was actually measured multiple times by the method illustrated by FIG. 1 , the measuring values were spread within a range of about 15 μm. This is supposedly because a large number of metal components are used for the member fixing the lens 41 and the mirror moving device 43 in the reference optical path 4 , those metal components undergo expansion or contraction due to changes in room temperature or other temperature changes, and the reference optical path length changes.
Assuming that the temperature does not change at all, the polishing amount can be determined in a real time mode by measuring the change in the total length of the optical fiber which is being measured, but in order to realize such a state, the polishing needs to be performed in a thermostat or with the temperature control in the mirror moving device (for example, control using a Peltier element), and such a method for measuring the polishing amount of an optical fiber component can hardly be considered as a high-utility method.
FIG. 2 is an explanatory drawing illustrating a tip portion length measuring method for the optical fiber component 1 using the OCT. This method is identical to that illustrated by FIG. 1 , except that the optical fiber component 1 being measured is attached instead of the optical fiber 10 being measured which is depicted in FIG. 1 . In this case, the optical fiber component 1 is obtained by connecting an end cap 13 as a tip portion to the optical fiber 10 , as depicted in FIG. 5(A) . The specific feature of this configuration is that the optical fiber component is produced such that the light is also reflected at the boundary surface of the optical fiber 10 and the end cap 13 . The reference numeral 11 in FIG. 5 denotes an optical fiber core.
Part of the light that has been branched by the fiber coupler 3 and entered the optical fiber component 1 being measured is reflected at the boundary surface of the optical fiber 10 and the end cap 13 , and the return light reaches the light receiver 6 through the fiber coupler 3 and the optical fiber 60 . The length La of the optical fiber 10 (length to the boundary surface) can be measured by the method illustrated by FIG. 1 on the basis of this return light and the return light of the reference optical path.
Further, part of the light that has been branched by the fiber coupler 3 and entered the optical fiber component 1 being measured is transmitted by the boundary surface of the optical fiber 10 and the end cap 13 and reflected by the tip surface of the end cap 13 , and the return light thereof reaches the light receiver 6 through the optical fiber 10 , the fiber coupler 3 , and the optical fiber 60 . The total length (total length of the optical fiber 10 and the end cap 13 ) Lb of the optical fiber component 1 can be measured by the method illustrated by FIG. 1 on the basis of this return light and the return light of the reference optical path.
Therefore, the length Lc (=Lb−La) obtained by subtracting the length La of the optical fiber 10 from the total length Lb of the optical fiber component 1 becomes the length of the end cap 13 .
The lengths La and Lb have a spread within a range of about 15 μm, which is caused by temperature changes, in the same manner as in the case illustrated by FIG. 1 , but since the effect of the measuring error caused by temperature changes is the same in La and Lb, the error in the length Lc (=Lb−La) is eliminated and an accurate value is obtained.
When the length Lc of the end cap 13 of the optical fiber component 1 was actually repeatedly measured multiple times by the method illustrated by FIG. 2 , the measuring value was within a range of less than ±0.5 μm.
Further, since Lc is the difference (difference in the reference optical path length) between the mirror position when the return light of the reference optical path 4 interferes with the return light reflected from the tip surface of the end cap 13 and the mirror position when the return light of the reference optical path 4 interferes with the boundary surface reflection return light, it is not always necessary to measure the La and Lb, and the Lc can be determined by the difference in the mirror positions (difference in the reference optical path length).
Where the length Lc of the end cap 13 is measured while polishing the optical fiber component 1 , the reduction amount of Lc, that is, the polishing amount, is obtained.
The specific feature of the configuration depicted in FIG. 2 , is that the optical fiber component 1 is fabricated such that the light is also reflected at the boundary surface of the optical fiber 10 and the end cap 13 . However, the actual optical fiber components are required to be free of loss on the boundary surface of the optical fiber and the end cap, and where the optical fiber and the end cap are correctly connected by welding and practically no light is reflected on the boundary surface, the length Lc of the end cap cannot be determined by the method illustrated by FIG. 2 .
The present invention provides a method for measuring a polishing amount of an optical fiber component while performing polishing, the method including: branching an inspection light among a reference optical path having a variable optical path length, an optical fiber component being measured, and a comparison optical path, and determining a polishing amount of the optical fiber component by a change amount of a difference Lc between a reference optical path length when return light of the reference optical path interferes with return light of the optical fiber component being measured and a reference optical path length when the return light of the reference optical path interferes with return light of the comparison optical path.
In the present invention, the return light of the comparison optical path is used instead of the return light from the boundary surface depicted in FIG. 2 , and the difference Lc in length between the optical fiber component and the comparison optical path can be measured with a high accuracy by the difference (difference in reference optical path length) Lc between the mirror position when the return light of the reference optical path 4 and the return light reflected from the tip surface of the end cap 13 interfere with each other, and the mirror position when the return light of the reference optical path 4 and the return light of the comparison optical path interfere with each other.
Where the Lc is measured while polishing the optical fiber component, since the length of the comparison optical path is constant, the reduction amount of Lc becomes the polishing amount of the optical fiber component.
The present invention also provides the method for measuring a polishing amount of an optical fiber component, wherein the optical fiber component is obtained by welding an end cap to an optical fiber tip.
In the present invention, the optical fiber component which is the measuring object can be configured by welding the tip of an optical fiber to an end cap.
A variety of optical fibers, such as a single-mode optical fiber, a multiple-mode optical fiber, and a polarization-maintaining optical fiber (PMF) can be used. The end cap is a coreless silica glass fiber. FIG. 5(A) illustrates an example of such an optical fiber component in which a round columnar end cap 13 is welded to the tip of a single-mode optical fiber (SMF) 10 .
The present invention also provides the method for measuring a polishing amount of an optical fiber component, wherein the optical fiber component is obtained by welding a lens fiber to an optical fiber tip.
In the present invention, the optical fiber component which is the measuring object can be configured by welding a lens fiber to an optical fiber tip.
A variety of optical fibers, such as a single-mode optical fiber, a multiple-mode optical fiber, and a polarization-maintaining optical fiber (PMF) can be used. The lens fiber is, for example, a GRIN lens (Graded Index Lens) which is a distributed-index lens of a round columnar shape. FIG. 5(B) illustrates an example of such an optical fiber component in which a round columnar lens fiber 14 (GRIN lens) is welded to the tip of the single-mode optical fiber (SMF) 10 .
The present invention also provides the method for measuring a polishing amount of an optical fiber component, wherein the inspection light is branched among a reference optical path having a variable optical path length, a plurality of optical fiber components being measured, and a comparison optical path, and a polishing amount is determined by a change amount of the Lc with respect to each optical fiber component being measured.
In the present invention, the polishing amount can be measured with respect to each optical fiber component while polishing a plurality of optical fiber components at the same time.
The present invention also provides a device for measuring a polishing amount of an optical fiber component, including:
a light source of inspection light;
a brancer that branches the inspection light among a reference optical path having a variable optical path length, an optical fiber component being measured, and a comparison optical path; and
a light receiver that receives return light of the reference optical path, the optical fiber component being measured, and the comparison optical path, wherein
the light receiver determines a polishing amount of the optical fiber component by a change amount of a difference Lc between a reference optical path length when return light of the reference optical path interferes with return light of the optical fiber component being measured and a reference optical path length when the return light of the reference optical path interferes with return light of the comparison optical path.
The present invention also provides the device for measuring a polishing amount of an optical fiber component, wherein the optical fiber component is obtained by welding an end cap to an optical fiber tip.
The present invention also provides the device for measuring a polishing amount of an optical fiber component, wherein the optical fiber component is obtained by welding a lens fiber to an optical fiber tip.
The present invention also provides the device for measuring a polishing amount of an optical fiber component, wherein
the brancher branches the inspection light among a reference optical path having a variable optical path length, a plurality of optical fiber components being measured, and a comparison optical path, and
the light receiver determines a polishing amount by a change amount of the Lc with respect to each optical fiber component being measured.
Advantageous Effects of Invention
The method for measuring a polishing amount of an optical fiber component in accordance with the present invention enables direct, accurate and easy measurements of the polishing amount of an optical fiber component, regardless of the polishing amount of a ferrule. Therefore, it is unnecessary to align the tip portion of the ferrule with the tip portion of the fiber component when the optical fiber component is inserted into the ferrule, and the operation efficiency can be increased.
The method for measuring a polishing amount of an optical fiber component in accordance with the present invention can be easily implemented with the device for measuring a polishing amount of an optical fiber component in accordance with the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory drawing illustrating a method for measuring the length of an optical fiber using an OCT.
FIG. 2 is an explanatory drawing illustrating a method for measuring the length of the tip portion of the optical fiber component using an OCT.
FIG. 3 is an explanatory drawing illustrating the method and device for measuring the polishing amount of an optical fiber component in accordance with the present invention.
FIG. 4 is an explanatory drawing illustrating the method and device for measuring the polishing amount of an optical fiber component in accordance with the present invention.
FIG. 5 is an explanatory drawing illustrating an example of an optical fiber component.
FIG. 6 is an explanatory drawing illustrating another example of the optical path length change unit for the reference optical path.
FIG. 7 is an explanatory drawing illustrating the conventional method for measuring the polishing amount of an optical fiber component.
DESCRIPTION OF EMBODIMENTS
FIG. 3 is an explanatory drawing illustrating the method and device for measuring the polishing amount of an optical fiber component in accordance with the present invention.
The device includes a light source 2 for inspection light, a reference optical path 4 with a variable optical path length, a comparison optical path 5 , an inspection light brancher, and an optical fiber component 1 being measured which is the measuring object.
The light source 2 and a light receiver 6 are connected to one end side of a fiber coupler 3 through an optical fiber 20 and an optical fiber 60 , respectively. A fiber coupler 3 a is connected through an optical fiber 30 , and the reference optical path 4 is connected to the other end side. The optical fiber component 1 being measured (measuring object) and the comparison optical path 5 are connected to the other end side of the fiber coupler 3 a.
A variety of light sources of the inspection light can be used. For example, a 1310 nm SLD (Super Luminescent Diode) light source can be used.
The brancher is the coupler 3 and the fiber coupler 3 a connected thereto by the optical fiber 30 .
The reference optical path 4 has an optical fiber 40 , a lens 41 provided at the tip thereof, and an optical path length change unit. The optical path length change unit has a mirror 42 which is mounted on a mirror moving device 43 and faces the lens 41 , and the length of the reference optical path 4 is changed by moving the mirror 42 with the moving device 43 in the direction of approaching the lens 41 and withdrawing therefrom. The mirror 42 is moved at all times during the measurements.
Position information on the mirror in the mirror moving device 43 is transmitted to the light receiver 6 .
The comparison optical path 5 has a constant length, and no restriction is placed thereon, provided that the return light is generated. For example, a single-mode optical fiber can be used.
The light receiver 6 is provided with a light receiving element that receives return light from the reference optical path 4 , the optical fiber component 1 being measured, and the comparison optical path 5 . The light receiver also includes a device (microcomputer) that determines a change amount of the difference Lc between the length of the reference optical path 4 when the return light of the reference optical path 4 interferes with the return light of the optical fiber component 1 being measured and the length of the reference optical path when the return light of the reference optical path 4 interferes with the return light of the comparison optical path 5 , that is, the polishing amount of the optical fiber component 1 . The length of the reference optical path 4 is obtained from the mirror position information transmitted from the mirror moving device 43 .
The light emitted from the light source 2 is branched by the fiber coupler 3 , and part thereof passes through the optical fiber 30 to the fiber coupler 3 a and is branched therein. One branched part enters the optical fiber component 1 being measured, and the other branched part enters the comparison optical path 5 (optical fiber). The light that has entered the optical fiber component 1 being measured is reflected at the tip surface thereof, and the return light thereof reaches the light receiver 6 through the fiber coupler 3 a , the optical fiber 30 , the fiber coupler 3 , and the optical fiber 60 . The light that has entered the comparison optical path 5 (optical fiber) is reflected at the tip of the comparison optical path 5 , and the return light thereof reaches the light receiver 6 through the fiber coupler 3 a , the optical fiber 30 , the fiber coupler 3 , and the optical fiber 60 .
The light that has been branched by the fiber coupler 3 and has entered the reference optical path 4 is emitted as a substantially parallel beam from the lens 41 at the tip of the optical fiber 40 and reflected by the mirror 42 . The return light thereof reaches the light receiver 6 through the lens 41 , the optical fiber 40 , the fiber coupler 3 , and the optical fiber 60 .
The light receiver 6 can accurately measure the difference Lc in length between the optical fiber component 1 and the comparison optical path 5 by determining the difference Lc (difference in the length of the reference optical path 4 ) between the position of the mirror 42 when the return light of the reference optical path 4 and the return light reflected from the tip surface of the optical fiber component 1 which is being measured interfere and the position of the mirror 42 when the return light of the reference optical path 4 and the return light of the comparison optical path 5 interfere. Where the Lc is measured while the optical fiber component 1 is polished with the polishing machine 7 , since the length of the comparison optical path is constant, the decrease amount of Lc becomes the polishing amount of the optical fiber component 1 .
FIG. 4 is an explanatory drawing illustrating the method and device for measuring the polishing amount of an optical fiber component in accordance with the present invention.
In FIG. 4 , the fiber coupler 3 a depicted in FIG. 3 is replaced with a channel selector 3 b , and a plurality of optical fiber components 1 being measured and one comparison optical path 5 are connected to the channel selector 3 b.
In FIG. 4 , the light emitted from the light source 2 is branched by the fiber coupler 3 , and part thereof passes through the optical fiber 30 to the channel selector 3 b and is branched therein. The branched light enters the plurality of optical fiber components 1 being measured, and the other branched part enters the single comparison optical path 5 (optical fiber). The light that has entered the plurality of optical fiber components 1 being measured is reflected at the tip surface thereof, and the return light thereof reaches the light receiver 6 through the channel selector 3 b , the optical fiber 30 , the fiber coupler 3 , and the optical fiber 60 . The light that has entered the comparison optical path 5 (optical fiber) is reflected at the tip of the comparison optical path 5 , and the return light thereof reaches the light receiver 6 through the channel selector 3 b , the optical fiber 30 , the fiber coupler 3 , and the optical fiber 60 .
The light that has been branched by the fiber coupler 3 and has entered the reference optical path 4 is emitted as a substantially parallel beam from the lens 41 at the tip of the optical fiber 40 and reflected by the mirror 42 . The return light thereof reaches the light receiver 6 through the lens 41 , the optical fiber 40 , the fiber coupler 3 , and the optical fiber 60 .
The light receiver 6 can accurately measure the difference Lc in length between the optical fiber component 1 and the comparison optical path 5 by the difference (difference in the length of the reference optical path 4 ) Lc between the position of the mirror 42 when the return light of the reference optical path 4 and the return light reflected from the tip surface of each optical fiber component 1 which is being measured interfere and the position of the mirror 42 when the return light of the reference optical path 4 and the return light of the comparison optical path 5 interfere. Where the Lc is measured while the plurality of optical fiber components 1 is polished with the polishing machine 7 , since the length of the comparison optical path is constant, the decrease amount of Lc in each optical fiber component becomes the polishing amount of each optical fiber component 1 .
Thus, with the measuring method and device depicted in FIG. 4 , the polishing amount of each optical fiber component can be measured in a real-time mode when a plurality of optical fiber components is measured at the same time.
FIG. 6 illustrates another example of the optical path length change unit in the reference optical path.
The optical path length change unit depicted in FIG. 6 has a mirror 42 and a rotor 44 . The rotor 44 has a pair of mirrors 44 a , 44 b , which is provided at a right angle to each other, and rotates as indicated by an arrow. The light emitted from the lens 41 is reflected by the mirrors 44 a , 44 b and then reflected by the mirror 42 to produce the return light which is reflected by the mirrors 44 b , 44 a and falls on the lens 41 . Where the rotor 44 is rotated, the optical path length from the lens 41 to the mirror 42 changes, and the optical path length of the reference optical path changes.
INDUSTRIAL APPLICABILITY
The optical fiber component that can be measured in accordance with the present invention is not limited to that depicted in FIG. 5 , and includes all of the components for which the light reflected by the tip surface is the return light. The optical fiber component in accordance with the present invention is also inclusive of an independent optical fiber which is not connected at the tip, an independent optical fiber with an oblique tip shape or PC (Physical Contact) shape, and an end cap or a lens product, and the polishing amount thereof can be measured in accordance with the present invention.
The present invention uses TD-OCT (time domain system) among the OCT techniques, the advantage thereof being the possibility of using a large number of techniques in the field of optical communication. For example, as for a light source, a 1310 nm SLD light source can be used and an inexpensive device configuration can be realized. Such a configuration is, however, not limiting, and SS-OCT (frequency sweeping system), which has been used in medicine or the like, and other systems can be also used.
REFERENCE SIGNS LIST
1 optical fiber component
10 optical fiber
11 core
12 coating
13 end cap
14 lens fiber
15 ferrule
2 light source
3 fiber coupler
3 a fiber coupler
3 b channel selector
30 optical fiber
4 reference optical path
40 optical fiber
41 lens
42 mirror
43 mirror moving device
44 rotor
44 a mirror
44 b mirror
5 comparison optical path
6 light receiver
7 polishing machine | The polishing amount of an optical fiber component can be measured directly, accurately and easily in a real-time mode during polishing, regardless of the polishing amount of a ferrule. Provided is a method for measuring the polishing amount of an optical fiber component while performing polishing, the method including: branching an inspection light among a reference optical path having a variable optical path length, an optical fiber component being measured, and a comparison optical path, and determining a polishing amount of the optical fiber component by a change amount of a difference Lc between a reference optical path length when return light of the reference optical path interferes with return light of the optical fiber component being measured and a reference optical path length when the return light of the reference optical path interferes with return light of the comparison optical path. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for reducing sheeting during polymerization of alpha olefins and more particularly to a method for reducing sheeting during polymerization of polyethylene.
2. Summary of the Prior Art
Conventional low density polyethylene has been historically polymerized in heavy walled autoclaves or tubular reactors at pressures as high as 50,000 psi and temperatures up to 300° C. or higher. The molecular structure of high pressure, low density polyethylene (HP-LDPE) is highly complex. The permutations in the arrangement of their simple building blocks are essentially infinite. HP-LDPE's are characterized by an intricate long chain branched molecular architecture. These long chain branches have a dramatic effect on the melt rheology of these resins. HP-LDPE's also possess a spectrum of short chain branches, generally 1 to 6 carbon atoms in length. These short chain branches disrupt crystal formation and depress resin density.
More recently, technology has been provided whereby low density polyethylene can be produced by fluidized bed techniques at low pressures and temperatures by copolymerizing ethylene with various alpha-olefins. These low pressure LDPE (LP-LDPE) resins generally possess little, if any, long chain branching and are sometimes referred to as linear LDPE resins. They are short chain branched with branch length and frequency controlled by the type and amount of comonomer used during polymerization.
As is well known to those skilled in the art, low pressure, high or low density polyethylenes can now be conventionally provided by a fluidized bed process utilizing several families of catalysts to produce a full range of low density and high density products. The appropriate selection of catalysts to be utilized depends in part upon the type of end product desired, i.e., high density, low density, extrusion grade, film grade resins and other criteria.
The various types of catalysts that can be employed to produce polyethylene in fluid bed reactors are generally disclosed in U.S. Pat. Nos. 4,855,370; 4,803,251; 4,792,592; 4,532,311; and 4,876,320.
Also disclosed in said patents is the incidence of "sheeting" in the reaction system when certain of the catalysts are utilized.
A strong correlation exists between sheeting and the presence of excess negative or positive static charges. This is evidenced by sudden changes in static levels followed closely by deviation in temperatures at the reactor wall whereby catalyst and resin particles adhere to the reactor walls due to static forces. If allowed to reside long enough under a reactive environment, excess temperatures can result in particle fusion. These temperature deviations are either high or low. Low temperatures indicate particle adhesion causing an insulating effect from the bed temperature. High deviations indicate reaction taking place in zones of limited heat transfer. Following this, disruption in fluidization patterns is generally evident, catalyst feed interruption can occur, product discharge system pluggage results, and thin fused agglomerates (sheets, regardless whether they come loose from reactor walls) are noticed in the granular product. The critical static voltage level for sheet formation is a complex function of resin sintering temperature, operating temperature, drag forces in the fluid bed, catalyst activation energy, resin particle size distribution and recycle gas composition.
Numerous causes for static charge exist. Among them are generation due to frictional electrification (triboelectrification) of dissimilar materials, limited static dissipation, introduction to the process of minute quantities of prostatic agents, excessive catalyst activities, etc.
It is generally believed that when the charge on the particles reaches the level where the electrostatic forces trying to hold the charged particle near the reactor wall exceed the drag forces in the bed trying to move the particle away from the wall, a layer of catalyst-containing polymerizing resin particles forms a non-fluidized layer near the reactor wall. Heat removal from this layer is not sufficient to remove the heat of polymerization because the non-fluidized layer near the wall has less contact with the fluidizing gas than do particles in the fluidized portion of the bed. The heat of polymerization increases the temperature of the non-fluidized layer near the reactor wall until the particles melt and fuse. At this point other particles from the fluidized bed will stick to the fused layer and it will grow in size until it comes loose from the reactor wall. The separation of a dielectric from a conductor (the sheet from the reactor wall) is known to generate additional static electricity thus accelerating subsequent sheet formation.
The above patents also disclose the methods and techniques for substantially reducing the incidence of sheeting in the reaction system. Thus, U.S. Pat. No. 4,876,320 discloses a method for polymerization of one or more alpha-olefins in a fluidized bed reactor in the presence of a catalyst prone to cause sheeting wherein the static electric charges in the reactor at the site of possible sheet formation is maintained below static voltage levels which could otherwise cause sheet formation.
U.S. Pat. No. 4,792,592 maintains static electric charges in the reactor below sheeting levels by creating areas of localized field strength within the reactor for the promotion of electrical discharge to ground.
U.S. Pat. No. 4,803,251 utilizes a chemical additive which generates either a positive or negative charge responsive to particular static levels in the reactor.
U.S. Pat. No. 4,532,311 teaches the introduction of a chromium containing compound into the reactor in such a manner as to contact the surfaces of the reactor in order to reduce the incidence of sheeting.
The present invention provides an alternate and preferred method for reducing the incidence of sheeting during the fluidized bed polymerization of alpha-olefins which employ catalysts prone to cause sheeting.
SUMMARY OF THE INVENTION
Broadly contemplated, the present invention provides a method for reducing sheeting during polymerization of alpha-olefins in a fluidized bed employing catalysts prone to cause sheeting which comprises feeding a material carrying a static electric charge opposite to the static charge in said bed, said opposite charge of said material being generated by passing said material in contact with a surface adapted to impart said static electric charge to said material opposite the charge existing in said bed.
In one aspect of the invention, the surface which imparts a charge to the material opposite to the charge existing in the fluidized bed is contained in a spray gun, preferably a powdered spray gun through which material in the form of particles receiving the appropriate charge are directed into the reaction system.
In another aspect of the invention, the surface is contained in one or more tubes, strategically positioned to permit passage of the appropriate charged particles into the reaction system.
Other aspects and objects of the invention will become apparent from the following description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Although the process can be practiced in any polymerization system which experiences agglomeration of polymers, the process is preferably applicable for preventing agglomeration of polymers in a fluidized bed reactor.
The fluidized bed reactor can be of the type described in U.S. Pat. Nos. 4,558,790 and 4,876,320, the teachings of which are incorporated herein by reference. Other types of conventional reactors for the gas phase production of, for example, polyethylene or ethylene copolymers and terpolymers can also be employed. At the start up, the bed is usually made up of polyethylene ganular resin. During the course of the polymerization, the bed comprises formed polymer particles, growing polymer particles, and catalyst particles fluidized by polymerizable and modifying gaseous components introduced at a flow rate or velocity sufficient to cause the particles to separate and act as a fluid. The fluidizing gas is made up of the initial feed, make-up feed, and cycle (recycle) gas, i.e., monomer and, if desired, modifiers and/or an inert carrier gas. The fluidizing gas can also be a halogen or other gas. A typical cycle gas is comprised of ethylene, nitrogen, hydrogen, propylene, butene, or hexene monomers, diene monomers, either alone or in combination.
The materials which can be employed according to the present invention depend upon the type reaction system, temperature employed, and other variables. As is know, and in general, when two dissimilar materials are brought into contact or collide and separate, charge transfer from one of the materials to the other takes place. The charge transfer process between metals is explained in terms of electron transfer due to the difference in work function between the metals; however, charge transfer of insulator/metal contacts and insulator/insulator contacts is far from completely understood for different reasons.
At the point of contact, the equilibrium condition requires that their chemical potentials (Fermi levels) equalize. Upon transfer of electrons or ions through the contact areas, the one having a higher Fermi level acquires a positive charge and leaves the other with a negative charge. The electrostatic charge (number and direction of electrons) acquired by flowing particles depends upon numerous variables: bulk chemical composition of bodies, the characteristics of both surfaces in contact (composition, moisture, roughness), molecular structure, size and shape, state of electric charge before contact, temperature, atmosphere (composition, pressure, humidity), electromagnetic fields, type of contact (touching, impaction, rubbing), orientation of bodies during contact, area and duration of contact, relative velocity of bodies, and force between bodies.
With some exceptions, many polymers charge negatively when contacted by metals. It has been stated that, according to the triboelectrification series of materials and their permitivities (farad/meter), materials low in the series, having low values of permitivity (˜2), charge negatively when contacted with materials higher in the series whereas polymers on the top of the list of permitivity (˜4) tend to charge positively because of the presence of electron donating groups. The triboelectrification series of polymeric materials as disclosed by Stolka, M., "Hard Copy Materials," Chemtech, 487-495, August (1989) is indicated below.
______________________________________Positive Nylon Polymethyl methacrylate (carrier cores - iron, ferrite) Styrene butylmethacrylate copolymer Polyesters Polyacrylonitrile (carbon black) Polycarbonate PolystyrenePositive Nylon Polyethylene Polypropylene Polytetrafluoroethylene (Teflon ®Negative Halogenated polymers______________________________________
Upon transfer of electrons through contact areas between materials in high level and in low level, one in high level acquires a positive charge and leaves the other with a negative charge; e.g., rubbing a polyethylene particle on a polytetrafluoroethylene wall would leave the polyethylene particle with a positive charge and the polytetrafluoroethylene wall with a negative charge.
Thus, depending on the type static charges existing in the fluidized bed, appropriate selection of material contacting surfaces prior to the entry into the bed would ultimately result in neutralization of static charges in the bed thereby controlling sheeting incidents.
It has been found that various techniques can be employed for feeding the oppositely charged materials to the fluidized bed. Thus, the triboelectrically charged particles can be added to the reactor utilizing the recycle gas. In another technique, the triboelectrically charged particles are added to the reactor utilizing separate feeders. In still another technique, triboelectrically charged particles can be added to the reactor utilizing particles from the fluidized bed.
When the recycle gas is utilized for introducing triboelectrically charged particles to the reactor, the recycle gas stream is preferably one which contains a large amount of fines. The recycle gas in the reaction scheme is directed through a charging device which contain either positive or negative generating surfaces. These charging devices can be in the form of powder spray guns and tubes that generate either positive or negative charges on particles. Representative of the type of spray guns which can be employed are those available from Nordson Corporation under the trademark Tribomatic®. The charging devices are preferably positioned with respect to the reactor in a manner such that the recycle gas is directed to either a positive generating charge device or negative generating charge device in the recycle line whereby the appropriate charge is imparted to the material (in this case, fines) entering the reactor with the recycle gas. A system of bypass lines and valves can be utilized for selectively directing the recycle gas into the charging devices prior to entry into the reactor.
In another technique, the electrically charged particles can be added to the reactor utilizing a separate feeder(s). The material in the form of particles to be charged can be contained in a storage tank which is in communication with the appropriate charging devices. Again, the device can be of any previously described type which is capable of imparting a positive or negative charge to the particle in contact with the charging surface of the device. Advantageously, the particles can be directed through the device and into the reactor with the aid of the fluidizing gas which is directed through the appropriate devices by means of conventional valves and bypass lines. This technique is desirable for introducing fluidization aids, catalyst and other additives to the reactors which have received a charge according to the present invention.
In still another technique for practicing the invention, entrained fines from the expanded section of the reactor are fed through to the appropriate charging devices with, if necessary, the aid of a compressor and the appropriately charged particles are thereafter introduced into the reaction system responsive to the amount and type of static charges in the reactor.
The materials which can be introduced into the reaction system are those which are capable of receiving the desired charge and which do not substantially interfere with the reaction taking place. The materials are preferably in particle or powder form and can include for example, inorganic oxide powders, such as oxides, fluorides, or sulfides of various metal elements. For example, basic oxides, such as MgO, ZNo and AL 2 O 3 have positive charging tendencies and acidic oxides, such as SiO 2 , TiO 2 and Nb 2 O 5 have negative charging tendencies.
In addition, appropriate materials can include ethylene, homopolymers and copolymers, polypropylene homopolymers, polypropylene random and impact copolymers, EDPM, EPM and like materials.
As mentioned previously, the materials can be preferably added in particle or powder form and should be of a particle or powder size of about 0.001" to 0.1", preferably about 0.01" to 0.04".
The surface which is provided in the charging device depends upon the material to which the appropriate charge is to be imparted. The type surface can be fabricated from any of the polymeric materials mentioned previously in the triboelectrification series of polymeric materials. The surfaces can include stainless steel, glass, nylon and the like.
The following Examples will illustrate the invention. For the Examples, the following was utilized:
An electrostatic charging measurement unit, a cold model fluidized bed containing polyethylene resin and a pilot plant reactor producing colorable sticky ethylene propylene rubber resin (EPR).
A simple test unit was prepared to measure static generation of polyethylene, polypropylene particles and silica powder passing through Teflon®, nylon and stainless steel tubes. The polyolefin particles were filled in a 1000 cc bomb that was subsequently pressurized up to 50 psig by plant nitrogen to feed the particles through the tubes. Due to the pressure drop between the bomb and the atmospheric pressure measurement chamber, the particles were successfully sprayed with a very high speed. A static ball probe connected to a computer and a chart recorder was used to measure the static electricity charged on the sprayed particles.
A fluidized bed system instrumented to measure static potentials and pressure drops and to control gas velocity and bed temperature was used to study electrostatic phenomena. The system was composed of a fluidized bed, a heater and a nitrogen gas feed system with motor, valves and flow transmitters. The fluidized bed made of Plexiglas® columns was 5.5 inch in diameter and 8 ft. in length. A distributor plate fabricated from a stainless steel plate had 6 holes with semicircular caps covering the holes to prevent particles from falling down through the holes. Seven nozzles for static probes were located along the opposite side of the cylindrical column, i.e., 3", 6", 9", 12", 15", 18" and 21" from the distributor plate. To simulate reactor conditions, an aluminum liner was placed into the Plexiglas® column to make the inside surface conductive and was grounded with an earthed wire.
Plant nitrogen (i.e. unpurified, 150 psig) was used to fluidize particles and the superficial gas velocity was automatically controlled or regulated by flow transducers and a computer (Honeywell). The bed temperature was measured by a thermocouple and controlled by motor-valves with a heater which was also controlled by a computer. Experimental conditions for the electrostatic measurements were: Bed Temperature: 20°-80° C.; Gas Medium: Nitrogen; Superficial Gas Velocity: 0.4-2.0 ft/s; and Bed Weight: 3000-3800 gm.
The electrostatic probes were used to measure the static electricity in the fluidized bed and were designed for temporary installation on the column through nozzles. The probe electronics function as a 4 to 20 mA two-wire transmitter, permitting standard connection to the computer and recorders. The static probe used in the Examples included a steel rod covered with a Teflon® sleeve and a hemispherical tip.
For the pilot plant reactor tests, EPR polymer was produced continuously in a gas-phase fluidized bed reactor. The catalyst was vanadium-based and was supported on silica particles. The catalyst system included a cocatalyst such as tri-isobutyl aluminum and a promoter such as chloroform. The reactor was carried out in a fluidized bed reactor similar to the one shown in FIG. 1 of U.S. Pat. No. 4,994,534. Ethylene, hydrogen, and comonomers (combinations of propylene and diene)were continuously fed to the reactor. A fluidization aid such as calcined silica (calcined to remove chemically bound water and minimize the level of the hydroxyl groups) was also used. The calcined silica was fed to the reactor at short intervals to keep an acceptable concentration level of silica in the reactor to prevent defluidization or agglomeration.
Example 1 demonstrates the positive static charging of polypropylene and polyethylene fines which are directed through a charging device having a "Teflon®" surface.
EXAMPLE 1
Static generation of polypropylene and polyethylene particles flowing through a Teflon® tube was measured using the electrostatic charging measurement unit. The flow of polypropylene fine particles through a 3/8" Teflon® tube consistently generated very high positive static electricity. When the polypropylene fine particles was fed through the Teflon® tube under a differential pressure drop of 40 psi, positive static electricity of greater than +2000 Volt was measured.
When the same Teflon® tube was used to feed the polyethylene particles, positive static was also detected with a maximum value of +2000 Volt, but the magnitude of the static was less than that of polypropylene fines.
Example 2 demonstrates the negative static charging of polypropylene and polyethylene fines which are directed to a charging device having a Nylon surface.
EXAMPLE 2
When the polypropylene fine particles were sprayed by nitrogen gas under a differential pressure of 40 psig through a nylon tube (3/8" o.d.), negative static charging on the particle surface was achieved. The flow of the polyethylene particles through the nylon tube under a differential pressure of 40 psi generated negative static electricity of -600 Volt. At the beginning, positive spike was sometimes detected and, after a while, very high negative static was maintained until the particles in the feeding bomb was emptied.
Example 3 is similar to Example 2, except that stainless steel tubes were utilized to negatively charge the polypropylene particles.
EXAMPLE 3
A stainless steel tube (3/8: o.d.) negatively charged the polypropylene particles even greater than the nylon tube. When the polypropylene particles were fed through the stainless steel tube induced by a differential pressure drop of 40 psi, the flow of the particles generated very high negative static electricity with maximum value of -2000 Volt.
This Example 4 demonstrates the present invention wherein both negative and positive static electricity was neutralized by a "Teflon®" tube in a fluidized bed.
EXAMPLE 4
In order to neutralize both negative and positive static electricity in a cold model fluidized bed, the polyolefin particles were sprayed through Teflon®, nylon or stainless steel tubes into the fluidized bed depending upon the polarity of the static in the bed.
When the polyethylene and polypropylene particles were sprayed directly into the fluidized bed through a 3/8" Teflon®, tube, the sprayed particles were triboelectrically charged and changed polarity of the static in the fluidized bed.
Negative static of -50 Volt was changed to positive static of +50 Volt. When polypropylene particles were used using the same Teflon® tube, negative static was also changed to positive static.
In a different run, negatively charged fluidized beds were neutralized by positively charged particles directed through the Teflon® tube under the same previously described conditions.
EXAMPLE 5
This example demonstrates positive static neutralization by using a nylon tube leading directly to a fluidized bed reactor. The procedure was similar to Example 4.
Positive static electricity in the fluidized bed was effectively neutralized by the negatively charged PE & PP (independently) particles through nylon tubes of 3/8" o.d. and 1/2" o.d. When a polyethylene nylon tube of 1/2" o.d. was used, positive static of +400 Volt was reduced to +130 Volt. When polypropylene particles were charged and sprayed into the fluidized bed, static neutralization was easily achieved by continuously adding the negatively charged particles.
EXAMPLE 6
This Example demonstrates positive static neutralization when employing a stainless steel tube leading directly to a fluidized bed.
The procedure was similar to Examples 4 and 5.
Stainless steel tubes of 3/8" o.d. and 1/2" o.d. were also tested to charge polypropylene and polyethylene particles and to neutralize static electricity in a fluidized bed charged by silica powder. As soon as polypropylene fines were slowly added through the 3/8" stainless steel tube to the fluidized bed, very high negative static was detected until a regulating valve was shut off. When the valve was shut off, the negative static signal was changed to a negligible positive static. It was found that the static response was reproducible when the valve was opened after 15 minutes to confirm the previous results.
EXAMPLE 7
This Example demonstrates static charge generation by utilizing Triboelectric spray guns leading into a fluidized bed reactor.
Triboelectric Teflon® and nylon charge guns, Tribomatic® spray guns manufactured by Nordson Corp., were used to generate static charges on polyolefin particles.
Static charge generation by triboelectric Teflon® and nylon charge guns were measured by static ball probes in a cold model fluidized bed containing coarse polyethylene particles. Polyethylene fines were sprayed into the bed through a nozzle located at 3 inches above the distributor plate. When the resin particles were sprayed into the bed by the Teflon® spray gun, positive static electricity of +200 Volts was measured. On the other hand, the static electricity of the bed went to -500 Volts when the nylon charge gun was put in service.
EXAMPLE 8
This Example demonstrates static neutralization by employing spray guns in a cold model fluidized bed.
Silica was injected into the cold model fluidized bed to generate static electricity. In general, the Teflon® spray gun and the nylon spray gun generated positive static and negative static, respectively, in the fluidized bed containing the silica powder.
At the beginning of the test, positive static and negative static were measured at the bottom and at the top of the fluidized bed, respectively, after putting in 10 wt % of silica by total bed weight into the top of the bed. In order to neutralize the static in the fluidized bed, the nylon powder spray gun was turned on, which in turn reduced the positive static at the bottom of the bed from +1000 Volt to +250 Volt.
For the static neutralization of negative static, the Teflon® powder spray gun was tested in a cold model fluidized bed containing very low density polyethylene resin. To generate negative static, a mixture of 90 wt % silica and 10 wt % magnesium oxide powder was prepared and injected through a Teflon® tube. When the mixture was injected, negative static of -1000 Volt was measured. To be more effective, polypropylene fine particles were sprayed into the negatively charged fluidized bed. As soon as the positively charged particles were sprayed through the Teflon® tube, the very high negative static was virtually neutralized to zero static. Once the spray gun was turned off, after a couple of minutes, the static stated to show negative signals. Again, the Teflon® spray gun was applied. The negative static was neutralized again accordingly. When the spray gun was turned off, the neutral static slowly returned to negative static due to the presence of silica and magnesium oxide powders in the fluidized bed.
The Teflon® powder spray gun was used to neutralize negative static generated by 10 wt % of flour in a cold model fluidized bed. When the flour was injected into the bed, negative static of -300 Volt was measured. To neutralize the negative static, polypropylene fine particles were sprayed into the bed by the Teflon® charge gun. The negative static was completely neutralized by regulating the positive charged particles flow rate.
EXAMPLE 9
This example demonstrates the invention in a gas phase fluidized bed polymerization reaction vessel.
In this example, reactor operation was established using a 120 g/g prepolymerized catalyst (no flow, 10% C 3 ), under ethylene propylene monomer (EPM) conditions: C 3 /C 2 =0.4, H 2 /C 2 =0.00 1, C 2 PP=90 psi). The reactor was operated initially by using carbon black as a fluidization aid. When the reaction was well established, the level of carbon black was reduced and calcined silica was introduced as a fluidization aid while carbon was periodically fed when static level increased above -600 to -700 Volts. Each shot of silica during this operation increased the negative static level.
A Teflon® coiled tube of 1/2" o.d. placed inside 5/8" stainless steel tube was prepared to feed silica and to reduce the negative static generation of silica, i.e. Ultrasil®. Using the Teflon® coiled tube, the negative static generation due to silica in the reactor was significantly reduce. When the Teflon® lined coil was in service, the reactor was held at a slightly positive static level of 200-300 Volts although negative static spikes were observed whenever silica was injected to the reactor. The amplitude of the negative static spikes was as large as -800 Volts.
In addition, a Teflon® coiled tube with the same dimension and geometry as the one used on the silica feed line was used on the prepolymerized catalyst feed line. It was observed that the Teflon® coiled tube generated positive static on prepolymer particles when they were fed through the coil. Since then, the reactor operated smoothly without a need for carbon feed and with static under control for more than three days finally making colorable EPM products.
In the end, colorable EPM with and without silica (2-3 wt % Ultrasil®) was successfully produced in the reactor by controlling static activity of the reactor. Negative static generated by both a silica and the prepolymer catalyst was controlled by applying different antistatic techniques. Specifically, the use of surface modifications to the feed lines for both prepolymer and the fluidization aid was particularly effective in reducing the negative static generated by the silica particles. The most effective combination of feed line configurations was Teflon® lined stainless steel coil for feeding silica.
EXAMPLE 10
This Example is similar to Example 9 except that a polyethylene line was employed instead of the Teflon® line.
A 3/8" o.d. carbon impregnated polyethylene was placed inside a section of 1/2" stainless steel tubing to study the effect of this lining on reactor static activity. When the stainless steel tube was replaced by the polyethylene lined tube, negative static spike height occurring during silica injection was reduced from -800 Volts to -200 Volts.
EXAMPLE 11
This example is similar to Example 9 except that a portion of the stainless steel line was replaced by a Teflon® tube.
The reactor started under similar conditions as Example 9 using T-1 catalyst and TIBA/Chloroform catalyst system. Calcined silica was used as a white fluidization aid and, as a result, high level of negative static potential was generated due to conveying the silica through a stainless steel tube that extended from the feeder to the reactor. Replacement of a portion of the transfer line (about 15%) with a Teflon® coated tube, resulted in driving the static potential slightly positive. | A method for reducing sheeting during polymerization of alpha-olefins in a fluidized bed employing catalysts prone to cause sheeting which comprises feeding a material carrying a static electric charge opposite to the static charge in said bed, said opposite charge of said material being generated by passing said material in contact with a surface adapted to impart said static electric charge to said material opposite the charge existing in said bed. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of lateral alignment of the cross-direction profile control of a web as required by a papermaking process, in a paper machine, in which a certain cross-direction profile of the dried web, particularly the basis weight profile thereof, to be aligned is gauged or measured, and the profile measurement signal thus obtained is passed to a control system of the paper machine which provides a control signal suited to control the adjustment means of the cross-direction profile control provision. Also, the web is provided with at least one marker line, whose lateral shift or shifts is/are detected at the measurement point of the cross-direction profile of the dried web, or in the vicinity thereof. The detection of the lateral shift(s) is used to generate a measurement signal of the shift(s) which signal is employed to control the lateral alignment of the web profile adjustment.
Furthermore, the present invention relates to a control apparatus for the adjustment and alignment of the cross-direction profile of a web manufactured in a paper machine. The control apparatus comprises a measurement beam or equivalent element adapted to be positioned at the dry end of the paper machine, most advantageously in the vicinity of the reel-up station, a control system to which a measurement signal of the cross-direction profile of the web from a measurement sensor or sensors of the measurement beam is passed, and means which facilitate the cross-direction adjustment of the stock flow profile at the wet end of the paper machine (i.e., in the vicinity of the headbox), most advantageously utilizing a feedback signal formed from the measurement signal obtained from the control system mentioned in the foregoing reference to the paper machine headbox. Also, the apparatus may include an applicator apparatus of a marker line or lines to be made onto the web, sensor means adapted in conjunction with or to the vicinity of a measurement beam or equivalent element, whereby the sensor means is capable of measuring the lateral shift(s) of the marker line(s). The apparatus also has an arrangement suited to control the lateral alignment of the stock flow profile adjustment provision on the basis of the measurement signal indicating the lateral shift(s).
Conventionally, a stock mixture is admitted via the headbox slice of paper or board machines in the form of a suspension jet onto a forming wire in a forming section or into a nip formed between two forming wires in the forming section. The cross-direction profile of the headbox slice determines the cross-direction profile of the discharged stock flow. The slice profile is adjustable and this slice profile control is also capable of compensating for those defects of the stock flow that occur in the headbox or stages preceding it.
Control systems for a paper or board machine are known in the art and are used for the adjustment of a certain cross-direction quality profile of the web being manufactured, particularly its basis weight profile, whereby such a control system comprises a plurality of actuators and a corresponding number of actuator control means. The actuators are arranged to function over the entire width of the web whose profile is to be adjusted. This type of prior art control system incorporates a process control computer or similar logic controller and a feedback loop including the measurement arrangement for the controlled cross-direction profile of the web.
As to the state-of-the-art for above-mentioned control systems of a paper machine, reference is made to Finnish Laid-Open Publication No. 85,731 (corresponding to the assignee's U.S. Pat. No. 5,381,341, the specification of which is hereby incorporated by reference herein, and European Patent Publication No. 0 401 188) filed earlier by the assignee. These documents disclose such a paper machine control system in which the individual actuators are provided with intelligent actuator controllers, and the information transfer in the control hierarchy of the system between a higher level control unit and the controllers of the individual actuators is implemented using a common bus. The control scheme of this control system is based on the distributed intelligence of the actuator controllers, which is parametrized only by the set values issued by the higher-level control system. Each actuator controller is seen by the higher-level system as an individual unit to which the set value is sent via the serial bus in digital format, after which the actuator controller takes care of the mechanical actuation in a self-contained manner based on its stored measurement/control algorithm.
The requirements set on the evenness of cross-direction profiles of both coated and uncoated paper are today tighter than ever primarily due to the elevated quality standards of printing processes and printed material.
However, profile control implemented by means of the lip adjustment of the headbox slice is hampered by certain shortcomings, i.e., that variations in the gap width between the slice lips cause cross-direction flow components in the jet flow of the discharging stock that in turn affect the evenness of the cross-direction profile of the fiber formation in the web. Accordingly, it is desirable to run the headbox with slice profile of maximally constant gap width. Due to these and other reasons, the tendency has recently been to develop and install so-called dilution headboxes in which the basis weight control of the web is principally implemented by controlling the cross-direction consistency profile of the stock flow discharged from the headbox. For practical embodiments of dilution headboxes, reference is made to, e.g., Finnish Patent No. 92228 and Finnish Patent Application No. 942780 filed by the assignee herein (which corresponds to U.S. Pat. No. 5,545,293).
Such consistency profile adjustment is implemented by feeding diluting water to those points of the web formation where the basis weight is higher than average via, e.g., manifold channels of the turbulence generator of the headbox. A problem associated with the use of dilution headboxes may arise therefrom that the web undergoes cross-direction "floating" during its formation and drying process so that the consistency profile adjustment performed based on the basis weight profile measured close to the reel-up end of the paper machine will be laterally misaligned, whereby a lateral shift of the profile control occurs that is extremely detrimental to the end result of the profile adjustment.
When the term dilution headbox is mentioned in the foregoing and later in the text, this term must be understood to generally refer to such headboxes in which cross-direction consistency profile adjustment of the stock flow is used. Such adjustment may also be implemented so that in addition to or instead of the dilution water, controlling stock flows may alternatively be used having a consistency different from the average consistency of the stock in the headbox. Also stock with a consistency higher than the average may be applied via the auxiliary feeds of the cross-direction profile adjustment provision. Lateral shift of the web is caused by the cross-direction shrinkage of the web occurring during the drying cycle of the web that is nonuniform over the width of the web. Such lateral shift is also partially caused by the lateral shifts of the web-supporting fabrics of the paper machine as well as the lateral velocity components of stock flow in the headbox slice channel and the discharged jet.
The dominating cause of the above-mentioned lateral shift is traceable to web shrinkage in the dryer, or more generally, any drying shrinkage in the formation of the web. Maximally the web shrinkage is in the order of about 20 cm to about 40 cm. Moreover, the higher web speeds of modern paper machines elevate the tendency of developing larger web speed differentials along the web path, which further results in length variations of the wires and, hence, the tendency of causing a contracted section in the web. Consequently, the cross-direction shrinkage of the web may be caused by both the drying process and the web speed differentials between the different wire groups along the web path.
The accuracy and stability of the lateral alignment in the control of web basis weight and other similar profiles becomes problematic particularly in conjunction with paper grade changes at the paper machine. It is conventional to operate such paper machines in which during each day the number of grade changes may mount up to several tens. By means of prior art control systems, the above-described lateral alignment of profile adjustment provision has been a difficult and time-consuming operation, whereby also the accuracy of such alignment leaves room for improvement. Such shortcomings may lead to lower availability of paper machines and even paper quality problems.
Conventionally, the lateral alignment of the cross-direction profile has been implemented using a method in which the adjustment screw of a certain headbox slice section is operated to cause a distinct change in the slice gap width at the adjustment screw and the effect of the change is measured with the help of the measurement beam of the basis weight profile at the dry end of the paper machine close to the reel-up station. This alignment method is hampered by its inaccuracy, since the change in the basis weight profile caused by means of the adjustment screw is extremely faint and flat.
Also known in the art for the above-mentioned lateral alignment is such a manual method in which a marker agent is injected into the stock jet discharged from the headbox and the lateral shift of the mark thus generated is detected, e.g., visually.
With regard to the state-of-the-art related to the present invention, reference is made to German Patent Publication No. DE 40 08 282 A1 (assigned to J. M. Voith GmbH). This publication discloses a method and apparatus employed for the lateral alignment of a cross-direction property profile of a paper web similar to that defined in the introductory part of the present patent application. This publication describes an injection header of marker lines suited to be placed at the dryer section of a paper machine, whereby the injection header is used to inject over the entire width of the paper web a series of mutually parallel marker lines, which are employed to determine the cross-direction shrinkage of the paper web. Additionally, the German publication mentions casually that such a shift measurement of the marker lines can be used for the control of the headbox slice lip. However, the principal content of the German publication relates to the control of web moisture profile modifying equipment of the dryer section along the paper web path such as steam boxes or infra-red radiant heaters.
One particular shortcoming of the method and apparatus disclosed in above-mentioned German publication is its incapability of determining the effect of cross-direction flow components occurring inside the paper machine headbox on the alignment of the cross-direction basis weight profile of the paper web. This disadvantage has been found particularly problematic in the dilution headbox, or consistency profile controlled headbox, which was mentioned above and will be described later in greater detail, because provided that the afore-mentioned shortcoming could be removed, this type of headbox can offer more accurate and defined control of basis weight than is conventional in the art.
OBJECT AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to achieve such a control method and apparatus for a paper machine that are capable of essentially overcoming the above-discussed problems.
To achieve this object and others, in the control method in accordance with the invention, the cross-direction alignment of the consistency profile adjustment provision adapted to the paper machine headbox is controlled on the basis of the above-described detection of the lateral shift of the web. In detail, the cross-direction profile of the dried web is measured at a measurement location and a profile measurement signal is generated based thereon, the profile measurement signal is input to a control system and an output control signal based thereon is generated, a lateral shift of the at least one marker line is detected at or in the vicinity of the measurement location from its position at the headbox discharge and a measurement signal based thereon is generated, and the consistency of the stock flow in the headbox in the cross-direction is adjusted based on the control signal in conjunction with the measurement signal of the detected lateral shift to control the cross-direction profile of the web characteristic.
Correspondingly, the apparatus according to the invention comprises a consistency profile adjustment provision adapted to the paper machine headbox and an arrangement in which the lateral alignment of the consistency profile control provision is adapted to be controlled on the basis of the above-mentioned lateral shift feedback signal.
An important advantage of the present invention over the prior art is that the lateral shift of the web detected by means of the marker line(s) is employed specifically in the control of the lateral alignment of the consistency profile adjustment provision adapted in conjunction with the paper machine headbox, whereby paper grades of improved basis weight profile over the prior art can be manufactured. An additional benefit of the invention is that also the cross-direction fiber orientation profile of the web can be made more homogeneous than in the prior art, because the headbox can be run with a more constant gap width of the headbox slice, whereby the cross-direction components of stock flow that determine the fiber orientation profile can be minimized.
In a particularly advantageous embodiment of the invention, when the marker agent is admitted along with the dilution water or equivalent medium of the consistency profile adjustment provision, that is, prior to the turbulence generator(s) of the headbox and its slice, most preferably immediately after the flow header of the headbox, the lateral shift of the marker line(s) can be made to further reflect such lateral shift components as those related to the cross-direction shifts of the stock flow, cross-direction shifts of the stock jet discharged from the slice and the cross-direction shifts of the paper machine web-forming wire and press fabrics. Accordingly, the consistency profile adjustment can be implemented in a more accurate and detailed manner than in the prior art and even a denser cross-direction spacing of the distribution points of the dilution water or equivalent profile control medium can be employed. Hence, a web with an improved basis weight and cross-direction fiber orientation profile over the prior art can be produced.
In the following the invention is described in greater detail with reference to a few exemplifying embodiments of the invention illustrated in the diagrams of the appended drawings, whereby the details of the illustrations are only exemplary and must not be understood in any manner to restrict the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
FIG. 1 illustrates the paper-making process and its control principle in a schematic top view partially complemented with a block diagram;
FIG. 2 is a diagrammatic illustration of the measurement beam employed in the invention and the marker line detector adapted thereto as viewed in the machine direction;
FIG. 3 is a diagrammatic machine-direction sectional side dilution headbox suited to implement the method according to the invention; and
FIG. 4 is a graph illustrating the lateral shift of the web in a paper machine over the entire width of the web (cross-directionally) caused by web shrinkage.
DETAILED DESCRIPTION OF THE INVENTION
Referring principally to FIGS. 1 and 3, an exemplifying construction of a dilution headbox is initially described suited for use as the operating environment of the embodiment according to the invention. At this preliminary juncture, it must be noted that the invention is also applicable to a number of other types of dilution headboxes. Notwithstanding the use of the term dilution headbox in the foregoing and later in the text, this term must be understood to refer to any headbox with an adjustable consistency profile in which the profile adjustment provision is implemented by feeding the headbox slice with sectional stock flows of different consistencies. With reference to drawings, a headbox 10 incorporates a flow header 11 into which stock is received as indicated by arrow PS in FIG. 1. From the header 11, the stock is divided via a flow distribution inlet piping 12 to an equalizing chamber 13 which is coupled to a pressurized-air-padded headbox air chamber 15 having a stock overflow dam 14. After the equalizing chamber 13 in the flow direction is a multi-pipe turbulence generator 16 comprising a set of parallel and superimposed pipes. The turbulence generator 16 exits in the flow direction F of the stock or fiber suspension into a slice chamber 17 from which a stock or fiber suspension jet J is discharged via a slice A onto a forming wire 20 running over a breast roll 21, or alternatively, into a forming nip between two wires (not shown), or any other forming section. Adapted to the slice A is a lip 22 whose profile is adjusted by means of a set of adjustment screws (not shown) actuated by actuator motors (not shown) in a conventional manner using a method described, e.g., in Finnish Laid-Open Publication No. 85,731 filed by the assignee herein.
Referring now in particular to FIG. 1, the cross-direction profiles, particularly the basis weight profile and the moisture content profile, of a dried web Wd are measured at the dry end of a paper machine just prior to the reel-up station by means of a measurement beam 40 equipped with a carriage 42 which performs gauging by traversing over the web in the cross-machine direction T--T. The resulting measurement signal values BW of the cross-direction basis weight profile are taken to a process control system 45 of the paper machine, which may further be connected to, e.g., a plant process computer (not shown).
Referring to FIGS. 1 and 3, the headbox shown in the diagrams is provided with a cross-direction consistency profile adjustment, that is, a cross-direction dilution profile control over the width of the web W in which control scheme, a feedback signal C 1 generated in the process control system 45 is employed to control the cross-direction consistency profile of the stock jet J discharged from the headbox and thereby particularly the cross-direction basis weight profile BW of the dried web Wd. The arrangement adapted for the dilution control comprises a feed header 30 for the dilution water, which may be, e.g., drainage water from the wire or stock with a consistency lower than the average, the feed header extends over the entire width of the headbox 10. The dilution water or equivalent medium is admitted into the feed header 30 in the direction of arrow DW. A set of distribution pipes 31 1 -31 N leaving the feed header 30 is provided with a set of control valves 32 1 -32 N . The valve set 32 is connected by a distribution pipe set 33 to distribution pipes 12a located close to the front wall of the headbox flow header 11, and before the flow distribution inlet piping 12. The control valve set 32 is equipped with a set of actuators 34 1 -34 N controlled by a set of control signals C 1 issued by the control system 45. The value of the subindex N refers to the number of adjustable feed points of dilution water. The number N in normally chosen to be from about 100 to about 250, whereby in a paper machine with a normal web width (approximately 8 m), the mutual cross-direction spacing of the dilution feed points will be in the range from about 30 mm to about 80 mm.
The dilution control principally functions in a conventional manner so that if a sensor 41 located at some point k along the cross-direction axis E above the web detects a basis weight greater than the average, the feedback loop 41,BW,45,C 1 ,32 steers the control valve 32 n at the corresponding cross-direction location above the web to release more dilution water into the corresponding distribution pipe 12a of the distribution pipe set 12, whereby a desired downward correction of basis weight is achieved at that cross-direction point x k . As described above, the accuracy of the lateral alignment of profile correction on the cross-direction axis has been wanting, particularly in conjunction with grade changes or long runs.
Referring now principally to FIGS. 1, 2 and 3, an advantageous embodiment of the invention is described in the following. As shown in FIGS. 1 and 3, to one of the dilution water feed pipes or distribution set pipes 33 after the control valve 32 thereof, at point 38, a marker agent injection pipe 37 is connected into which the marker agent is dosed via a control valve 36 from a marker agent source 39a via a pump 39 and an inlet pipe 35. The function of the control valve 36, principally in an on/off fashion, is controlled by a control signal C 2 issued by the control system 45.
The marker agent is most advantageously admitted in conjunction with grade change at the paper machine by means of the marker agent injection system 35-39 into a dilution water feed pipe 33 located at a cross-direction point x 0 above the web. As a result, the paper web W is marked with a marker line M forming a kind of cross-direction "reference" line at the marker agent injection point x 0 . As the web W undergoes a possible cross-direction "drift" and shrinkage due to reasons described above, on reaching the measurement beam 40, the marker line M on the dried web Wd has shifted by a cross-direction distance Δx relative to the initial injection point x 0 of the marker line M. It must be noted herein that the web path in FIG. 1 between the headbox 10 and the measurement beam 40 includes such sections as the paper machine former, dryer, press and a possible finishing section, e.g., a sizing press and/or a machine-glaze calender, all of which are not shown, and that the measurement beam 40 is positioned just prior to the reel-up section (not shown).
Referring to FIGS. 1 and 2, the measurement beam 40 is adapted to carry a measurement apparatus or carriage 42 capable of detecting the cross-direction shift Δx of the marker line M. This measurement apparatus may be formed by, e.g., a set of radiation sensors 43 1 -43 M . That sensor 43 R of the set which coincides with the marker line M receives the maximum intensity of radiation R and issues the corresponding position signal M(Δx) via the measurement apparatus to the control system 45 which further issues a control signal C 1 for the control of the actuator element set 34 1 -34 N of the control valve set 32 1 -32 N .
Referring now specifically to FIG. 2, the measurement beam apparatus 42 of the web shift Δx mounted in a stationary position on the measurement beam 40 can be replaced by an equivalent traversing measurement apparatus particularly if the marker lines Mi are made over the entire width of the web W. The traversing measurement apparatus 42 may be combined with the traversing sensor 41 that gauges the cross-direction basis weight profile BW of the web Wd.
The marker agent for the marker line M may be selected, e.g., from the group of fluorescent chemicals conventionally used in paper web coats. An example of one suitable agent is a fluorescent chemical belonging to the trade mark family TRASAR®T (manufactured by Nalco Chemicals Company) which agent is used as a marking chemical in industry. With the use of fluorescent marker agents, the area about the marker line M is flooded with ultra-violet light and the position of the marker line M is detected by means of conventional optical sensors such as a CCD (charge coupled device) array thereof.
Alternatively, an optical sensing arrangement based on light transmission through the web W or a similar principle may be used in the detection of the lateral shift Δx of the marker line M. Also other kinds of marker lines M compatible with optical detection may be used. Further, the marker agent may be selected from the group of radioactive isotopes having a sufficiently short half-life, typically in the order of about 10 minutes to 20 hours. The marker agent is appropriately selected such that it does not cause defects on the finished sheet. In exceptional cases, also visible marker agents, e.g., dyes can be used, whereby the length of web containing the marker lines injected at, e.g., the start of a grade change may be taken to the broke or trimmed off at the slitter.
The invention can also utilize a greater number of marker lines than one, whereby the marker lines are advantageously spaced symmetrically about the machine center line to those web areas where the greatest changes in the basis weight profile occur. Marker lines indicated by lines M i and M R in the diagram of FIG. 1 refer to the possibility of a plurality of marker lines. The number R of the marker lines is typically selected to be approximately in the range of 1 to about 300. When multiple marker lines are employed, a "mapping" of the cross-direction coordinates x of the web W is achieved at the plane of the measurement beam 40. Moreover, the use of multiple marker lines spaced sufficiently densely permits the detection of the cross-direction shrinkage profile of the web W from the mutual distances between the marker lines, whereby this information can be used in the control of the paper machine.
Furthermore, the marker line M, or alternatively, the marker lines M, M 1 , M R can be used to detect, and in special cases, even to control the cross-direction alignment of the web W and/or the lateral position of the press or dryer fabrics.
The marker line M need not be continuous, and it need not be applied continuously during the manufacture of the web W. The marker line M may be comprised of dots or dashes accomplished by means of the control valve 36 and the control signal C 1 . Most preferably the marker line M or the marker lines M 1 ,M R are applied after the machine has stabilized subsequent to a grade change, and the lateral shift Δx, or alternatively, the lateral shifts Δx i measured at several points across the web is/are measured, and the lateral shifts are stored in the memory of the control system 45 or a host process computer and are used for the cross-direction alignment of the dilution control during the entire run of the grade. If the sheet grade under production is run for a longer time, or a change of process parameter(s) or a disturbance occurs during the run, the lateral shift Δx or shifts Δxi can be recalibrated.
Referring to FIG. 4, the background of the invention is illustrated by a graph depicting the lateral shift Δx of the web measured from a paper machine, whereby the shift is caused by the cross-direction shrinkage of the web W. In the graph shown in FIG. 4, the vertical axis represents the lateral shift Δx of the web, while the horizontal axis is the cross-machine coordinate with the origin aligned at the center line of the paper machine. As can be seen from FIG. 4, the lateral shift Δx caused by the cross-direction shrinkage in a 9 m wide web is maximally approximately 170 mm to about 180 mm at the web edges, while the shift naturally is about 0 at the machine center line.
As is further evident from FIG. 4, the shrinkage related to the drying of the web and the lateral shift of the web caused thereby is a monotonous function of the x coordinate and generally essentially symmetrical about the machine-direction center line of the web. Based on this fact, the invention can utilize models of cross-direction shrinkage stored for different paper grades in the memory of the control system 45 or the host computer connected thereto. Such models can be updated even as simply as by measuring the lateral shift Δx of a single marker line. Additionally, the center line of the web or any other suitable, freely selectable point of the web may be marked with another marker line which can be used to determine a lateral shift caused by another reason than the cross-direction shrinkage of the web and to resolve the need for the lateral alignment of the consistency profile control of the paper machine headbox. A particularly advantageous embodiment of the invention uses three marker lines M 1 , M 2 and M 3 of which the center line is aligned with the center line of the web W and the two other lines are applied close to the edges of the web. The lateral lines M 1 and M 3 principally serve to indicate the lateral shift Δx of the web caused by the cross-direction shrinkage, while the lateral shift caused by other reasons than cross-direction shrinkage can be detected from the position of the center line M 2 .
Without departing from the scope and spirit of the invention, the different details of the invention can be varied widely. For instance, different combinations of marker agents and marker detecting sensors may be used in conjunction with different paper grades.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims. | A method and apparatus for lateral alignment of a cross-direction profile control of a web as required in a paper-making process. In the method, a certain cross-direction profile of a dried web, particularly the basis weight profile thereof, to be aligned is gauged. A profile measurement signal thus obtained is passed to a control system of the paper machine which provides a control signal suited to control adjustment devices of the cross-direction profile control provision. The web is provided with at least one marker line whose lateral shift or shifts is/are detected at the measurement point of the cross-direction profile of the dried web, or in the vicinity thereof. The detection of the lateral shift(s) is used to generate a measurement signal thereof which is employed to control the lateral alignment of the web profile adjustment provision. The information obtained from the detected lateral shift(s) then used in the control of the lateral alignment of the consistency profile control provision adapted in conjunction with the paper machine headbox. The marker agent used to make the marker line is injected to the stock at the inlet side of the stock feed channel to the paper machine headbox, most advantageously close to the control valve set of the consistency profile control provision. | 3 |
This is a continuation of application Ser. No. 814,740, filed on Dec. 27, 1991, now abandoned, which is a divisional of application Ser. No. 516,602, filed on Apr. 30, 1990, now U.S. Pat. No. 5,122,577.
TECHNICAL FIELD
The present invention relates to latex compositions having polycationic surface substituents. The latex compositions are useful as wet-strength agents in paper products.
BACKGROUND OF THE INVENTION
Water-soluble cationic resins are often used as wet-strength additives in papermaking. One widely used type of wet-strength resin is the polyamide/polyamine/epichlorohydrin material sold under the trade name KYMENE. See, for example, U.S. Pat. No. 3,700,623 to Keim, issued Oct. 24, 1972; and U.S. Pat. No. 3,772,076 to Keim, issued Nov. 13, 1973. Another group of water-soluble cationic wet-strength resins are the polyacrylamides sold under the trade name PAREZ. See, for example, U.S. Pat. No. 3,556,932 to Coscia et al, issued Jan. 19, 1971; and U.S. Pat. No. 3,556,933 to Williams et al, issued Jan. 19, 1971.
The cellulosic fibers used in papermaking are negatively charged. Since the water-soluble wet-strength resins are cationic (positively charged), they are deposited and retained well when directly added to the aqueous pulp slurry. Such "wet-end addition" is highly desirable in papermaking. Subsequently in the papermaking process, these resins cross-link and eventually become insoluble in water. When this occurs, the wet-strength resin acts as a "glue" to hold the fibers of the paper together. This results in the desired wet-strength property.
Paper products made with such resins often have a stiff, paper-like feel. To impart greater softness to the paper product, styrene-butadiene latexes can be used as the binder system. However, these styrene-butadiene latexes are usually either nonionic in character or else are partially amionic due to inclusion of anionic comonomers or surfactants. The nonionic styrene-butadiene latexes cannot be used as "wet-end additives" in a conventional papermaking process. Instead, these nonionic latexes have to be impregnated or pattern-printed on the subsequently laid paper furnish, such as by the process described in European Patent application 33,988 to Graves et al, published Aug. 19, 1981.
An anionic styrene-butadiene latex can be used in a conventional wet-end additive papermaking process by adding a cationic polyelectrolyte. See, for example, U.S. Pat. No. 4,121,966 to Amano et al, issued Oct. 24, 1978; and U.S. Pat. No. 2,745,744 to Weidner et al, issued May 15, 1956. The cationic polyelectrolyte used is typically a water-soluble cationic wet-strength resin. Basically, the cationic polyelectrolyte, when added, destabilizes the dispersed anionic latex particles which then flocculate and deposit on the paper fibers. Accordingly, the cationic polyelectrolyte and anionic styrene-butadiene latex cannot be combined together until the point at which they are used as the binder system in papermaking.
Styrene-butadiene latexes have also been modified to provide cationic groups chemically bound on the surface of the latex particles. See, for example, U.S. Pat. No. 4,189,345 to Foster et al, issued Feb. 19, 1980; and U.S. Pat. No. 3,926,890 to Huang et al, issued Dec. 16, 1975. Incorporation of the cationic groups on the surface of the latex particles converts the latex into a wet-end additive like the water-soluble cationic wet-strength resins. These cationic latexes appear to have adequate colloidal stability, especially when nonionic or preferably cationic surfactants are added. However, the deposition and retention of the cationic latex particles on the paper fibers does not appear to be very great. Indeed, the cationic latex of the Foster et al patent appears to require a co-additive to enhance the deposition of the latex particles on the paper fibers.
Accordingly, a cationic latex which combines: (1) colloidal stability; (2) enhanced deposition and retention of the latex particles on the paper fibers; and (3) enhanced wet-strength properties, would be highly desirable.
The polycationic latexes of this invention provide these desirable benefits.
Despite the various art-described attempts to improve wet-strength resins, the wet-strength resin of choice has remained the polycationic material, KYMENE. Unfortunately, as noted hereinabove, the use of excessive amounts of KYMENE can cause paper therewith to become not only stronger, but also stiffer, which is undesirable for some uses. Stated otherwise, KYMENE not only enhances the wet tensile strength of the paper, but also increases its dry tensile strength, thereby leading to a stiff or brittle feel. This is undesirable in situations where paper with a soft, more cloth-like feel is desired.
Moreover, it has now been determined that KYMENE-type polycationic water-soluble wet-strength resins can undesirably interact with anionic additives which the formulator may wish to incorporate into the paper. For example, various anionic super-absorbent materials have their absorbency undesirably lessened when KYMENE is present.
In the present invention, it has been discovered that KYMENE-type wet-strength resins can be effectively rendered water-insoluble, and thus rendered less reactive to anionic paper additives. Moreover, it has been discovered that the polycationic latexes of the present invention desirably enhance the wet-strength of paper treated therewith, but without causing the paper to have an undesirable stiff feel. In addition, the maximum wet strength obtained with KYMENE seems to peak at about 250 g/in (98.4 g/cm) (for Northern Softwood Kraft Handsheets) whereas the polycationic latexes herein can yield wet strengths as high as 1200 g/in (472.4 g/cm). These and other advantages of the present invention will be appreciated from the disclosure hereinafter.
Besides the papermaking art, there are circumstances where it would be desirable to impart a cationic finish to surfaces such as fabrics in order to provide an antistatic effect. The polycationic latexes of this invention may be considered as substitutes for the quaternary ammonium compounds now typically used as antistats.
BACKGROUND ART
U.S. Pat. Nos. 4,785,030 and 4,835,211 to Noda and Hager, issued Nov. 15, 1988 and May 30, 1989, respectively, describe cationic latexes which impart a soft feel to paper.
U.S. Pat. No. 4,189,345 to Foster et al, issued Feb. 19, 1980, describes a fibrous product containing papermaking pulp, a structured-particle latex having pH independent cationic groups bound at or near the particle surface and a co-additive. The structured-particle latex has a copolymer core of styrene and butadiene, and an encapsulating layer of styrene, butadiene and vinylbenzyl chloride which is reacted with 2-(dimethyl amino) ethanol to form quaternary ammonium groups. The co-additive can be a hydrolyzed polyacrylamide having a degree of polymerization of 5500 and is used to enhance deposition of the cationic latex on the pulp fibers. In making the fibrous product, the structure-particle latex and an aqueous solution of the co-additive are added to an aqueous slurry of the pulp, which is then dewatered and dried by heating.
U.S. Pat. No. 3,926,890 to Huang et al, issued Dec. 16, 1975, discloses a process for preparing a "stable" cationic latex which is described as having "excellent adsorption" (only about 69% absorption of latex based on Example 5) onto substrates such as pulp, paper and the like. The Haung et al cationic latexes are prepared by emulsion polymerization of a haloalkyl ester of acrylic or methylcrylic acid with another monosaturated compound and/or a conjugated diene compound (e.g., butadiene) in the presence of a nonionic or preferably cationic surface active agent, and then reacting a basic nitrogen-containing compound with this copolymer to form the respective ammonium salt.
U.S. Pat. No. 4,121,966 to Amano et al, issued Oct. 24, 1978, discloses a method for producing a fibrous sheet bonded with a latex flocculate. In this method, zinc white powders are added to a carboxy modified anionic latex. The pH of this mixture is adjusted to not less than 7, and then a water-soluble cationic polymer is added to obtain a latex flocculate. The latex flocculate is added to a fiber slurry which is formed into a sheet by a conventional papermaking process. Representative carboxy modified latexes include styrene-butadiene copolymers. Suitable water-soluble cationic polymers include polyamide-polyamineepichlorohydrin resins, polyethylene imine resins, cationic modified melamine-formalin resins, and cationic modified ureaformalin resins.
U.S. Pat. No. 2,745,744 to Weidner et al, issued May 15, 1956, discloses a method for incorporating polymeric or rubberlike materials into cellulosic fibers used to make paper. In this method, a colloidal dispersion of a hydrophobic polymer, such as a butadiene-styrene latex, is mixed with a paper pulp suspended in water. A poly-N-basic organic compound is then added to this mixture to cause particles of the colloidal dispersed material to adhere to the cellulosic fibers in the water suspension. The treated fiber is then formed into paper by conventional techniques.
SUMMARY OF THE INVENTION
The present invention encompasses the reaction product of a cationic polyamide/polyamine/epichlorohydrin wet-strength resin and a reactant (electrophiles or nucleophiles can be used) comprising an unsaturated polymerizable hydrocarbon moiety. Preferred compositions herein comprise the reaction product of a wet-strength resin containing repeat units of the general structural type ##STR1## wherein R is ##STR2## and a carboxylate reactant, wherein said carboxylate reactant contains an unsaturated group. Said carboxylate (or carboxylate-derived) reactant is preferably a member selected from the group consisting of acrylates, methacrylates, itaconates, vinyl benzoates, unsaturated epoxides such as glycidyl methacrylate, unsaturated chlorohydrins such as chlorohydrin methacrylate and unsaturated fatty acids and their reactive derivatives, e.g., acid hal ides and acid anhydrides, and mixtures thereof.
The invention also encompasses water-insoluble latex composition comprising the reaction product of a cationic polyamide/polyamine/epichlorohydrin wet-strength resin and a reactant comprising an unsaturated polymerizable hydrocarbon moiety, said reaction product being co-polymerized with latex-forming polymerizable monomers or oligomers. Preferred latex-forming polymerizable monomers or oligomers are selected from the group consisting of styrene, 1,3-butadiene, isoprene, propylene, ethylene, and mixtures thereof. Vinyl acetate, methyl acrylate, methyl methacrylate and t-butyl acrylate can also be used.
Preferred latex compositions herein comprise the reaction product of a wet strength resin containing repeat units of the general structural type ##STR3## wherein R is ##STR4## and a carboxylate reactant, said reaction product being co-polymerized with latex-forming polymerizable monomers or oligomers. Said carboxylate (or carboxylate-derived) reactant is preferably a member selected from the group consisting of acrylates, methacrylates, itaconates, vinyl benzoates, unsaturated epoxides such as glycidyl methacrylate, unsaturated chlorohydrins such as chlorohydrin methacrylate, unsaturated fatty acids and their reactive derivatives, e.g., acid halides and anhydrides, and mixtures thereof, and said latex-forming polymers or oligomers are preferably selected from the group consisting of styrene, 1,3-butadiene, isoprene, propylene, ethylene, and mixtures thereof. Vinyl acetate, methyl acrylate, methyl methacrylate and t-butyl acrylate can also be used.
A highly preferred latex composition herein comprises the reaction product of said cationic wet-strength resin and a reactant selected from acrylic acid, methacrylic acid, glycidyl methacrylate, and mixtures thereof, said reaction product being co-polymerized with styrene, 1,3-butadiene, or mixtures thereof.
The latex compositions according to this invention are preferably in the form of particles having an average size (sieve analysis) in the range of from about 10 nm to about 500 nm or to about several microns, preferably about 50 nm to about 500 rim. Such particles are conveniently formed as aqueous dispersions by the procedures disclosed hereinafter.
All percentages, ratios and proportions herein are by weight, unless otherwise specified.
DETAILED DESCRIPTION
The polyamide/polyamine/epichlorohydrin wet-strength resins used in the practice are fully described by Cart, Doane, Hamerstrand and Hofreiter, in an article appearing in the Journal of Applied Polymer Science Vol. 17, pp 721-735 (1973). Such resins are available as KYMENE (e.g., KYMENE 557) from Hercules, Inc. A commercial synthesis of such resins from adipic acid, diethylene triamine and epichlorohydrin is described in the Cart et al publication, ibid., and is U.S. Pat. No. 2,926,154 (Feb. 23, 1960) to G. I. Keim. Reference can be made to these publications for further details regarding the preparation of polyamide/polyamine/epichlorohydrin resins of the type employed to prepare the polycationic latexes herein.
In the practice of this invention, the aforesaid resin is reacted in such a way as to introduce a polymerizable hydrocarbon moiety into the resin's structure. Such moiety can be co-polymerized with other polymerizable latex-forming monomers or oligomers to form a latex incorporating the resin. The resulting latex is polycationic, by virtue of the presence of the resin's polycationic substituents.
While not intending to be bound by theory, it is reasonable to speculate that the overall reaction involves the following, wherein M--X is a reactant comprising a reactive group X which can be, for example, carboxylate (preferred), amine, alkyl halide, chlorohydrin, epoxide, xanthate, acid anhydride, or the like, and wherein M contains at least one --C═C-- bond, typically a C 2 -C 16 unsaturated hydrocarbyl group, preferably C 2 -C 6 . Examples include: acrylate, methacrylate, vinyl benzoate or other vinyl groups, unsaturated fatty acids and derivatives thereof, and the like. The reaction is speculated to occur at the 4-membered ring of KYMENE (i.e., schematically illustrated by the following) or at the secondary amine: ##STR5## wherein a, b, c and d are each integers typically in the range of 20-500 and R is as disclosed hereinabove. Alternatively, the OH moieties and/or the residual secondary amine of KYMENE are available as reaction sites. As an example, acryloyl chloride could react with KYMENE to produce the structure below: ##STR6## and glycidyl methacrylate could react with KYMENE to produce the structure below: ##STR7## Whatever the mechanism of reaction, the unsaturated hydrocarbon moiety is thus attached to the KYMENE and is available to react with various latex-forming monomers or oligomers, thereby incorporating the KYMENE into and onto the resulting latex particles.
To illustrate the reaction further, KYMENE can be reacted with a member selected from the group consisting of vinyl benzoic acid, itaconic acid, oleic acid, linoleic acid, 3-bromopropyl acrylate, dimethylaminopropyl acrylate, acrylolyl chloride, itaconic anhydride, the methyl ester of acrylic acid, and mixtures thereof, and the reaction product co-polymerized with a member selected from the group consisting of styrene, 1,3-butadiene, isoprene, propylene, ethylene, methyl acrylate, vinyl acetate, methyl methacrylate, t-butyl methacrylate, and mixtures thereof, to provide polycationic latexes.
While the Examples disclosed hereinafter provide more specific details, the following general principles for carrying out the reactions herein are provided for assistance to the formulator. The reactions are conveniently carried out in water. The reaction temperatures can be in the range of about 30° C. to about 100° C., but a 60° C. reaction temperature is convenient. Reaction times can vary according to the temperature selected but reaction at 60° C. for 40 hours is convenient for laboratory syntheses. An emulsifier, e.g., oleyl ethoxylate as VOLPO-20 (Croda, Inc.), can be used in the reaction mixture, and some of this may be co-polymerized into the latex. In any event, the presence of the emulsifier results in a desirably fine suspension of the latex particles in the reaction medium. On a laboratory scale, it is convenient to use sufficient materials to provide a solids content of the final latex suspension in the range from about 10% to about 25% (wt.). The resulting suspension can be used directly to treat paper, or the like. The following Examples illustrate the preparation of the polycationic latexes, but are not intended to be limiting thereof.
EXAMPLE I
KYMEME/Acrylic Acid/Styrene/Butadiene Latex
______________________________________Reagents Amount (grams)______________________________________VOLPO-20 0.322V-50* 0.072KYMENE** 0.722Acrylic Acid 0.14Styrene 2.861,3-Butadiene 4.29Distilled water as reaction medium 50 mls______________________________________ *V-50 initiator is 2,2' azobis(2amidopropane) dihydrochloride available from WAKO, USA. **As 5.5 g. of 13% solution.
The water reaction medium is sparged for 30 minutes with argon prior to use. A 250 ml glass reaction bottle equipped with a magnetic stir bar is flushed with nitrogen for 5 minutes. The KYMENE, VOLPO-20, V-50 initiator and distilled water are placed in the reaction bottle, which is sealed with a rubber gasket and two-holed bottle cap. The mixture is argon sparged for 30 minutes. The acrylic acid is added using a syringe and the styrene is added using a syringe. The reaction bottle is placed in an ice bath. The 1,3-butadiene is condensed in dry ice. Using a double-ended syringe and argon pressure, the 1,3-butadiene is added to the reaction vessel. A rubber septum is wired in place over the bottle cap and the reaction bottle is placed in an oil bath at 60° C. for 40 hours, with slow stirring. At the end of this time, the reaction product is pulled and strained through a fine wire sieve to provide a suspension of a captioned latex at a solids content of 13.5%.
EXAMPLE II
The reaction of Example I is repeated under the same conditions, but using 0.722 g of KYMENE and 0.358 g of acrylic acid. The reaction product is a 12.8% polycationic latex suspension.
EXAMPLE III
The reaction of Example I is repeated, but with the amount of KYMENE increased to 1.44 g (11.1 g of 13% solution). The reaction product is a 11.5% solids suspension of polycationic latex. In an alternative mode, the KYMENE level can be decreased to 2.77 g of a 13% (wt.) KYMENE solution to provide a polycationic latex suspension (13.6% wt. solids).
EXAMPLE IV
Following the procedure of Example I, a polycationic latex is prepared, but with the substitution of methacrylic acid (0.14 g) for the acrylic acid used in Example I, and with the use of 0.722 g of KYMENE. The reaction is allowed to proceed for 26 hours at 60° C. The reaction product is an aqueous suspension of a polycationic latex.
EXAMPLE V
Following the procedure of Example 1, a polycationic latex is prepared, but with the substitution of 0.14 g of glycidyl methacrylate for the acrylic acid used in Example I. The reaction product is an aqueous suspension of the polycationic latex.
EXAMPLE VI
Preparation of a Handsheet
2.65 g (2.50 g dry wt.) unrefined Northern Softwood Kraft (NSK) pulp is dispersed in 500 ml tap water at ambient pH (ca. 7.5).
5.0% (0.984 g) of the polycationic latex of Example I is added to the pulp slurry and stirred for 30 minutes.
The handsheet is made on a standard Deckle Box using tap water at ambient pH (ca. 7.5) and dried on a drum dryer at 110°-115° C.
EXAMPLE VII
The applicability of a polycationic latex as a wet-strength additive for a continuous papermaking process is as follows. Approximately 220 kg (dry weight) of refined northern softwood Kraft pulp is dispersed in water at the consistency of about 2.5% and kept in a stirred holding tank. About 400 liters of cationic latex prepared according to Example I are added to the pulp to achieve the wet-end deposition of the binder.
The latex-treated pulp is then fed to a pilot scale paper machine (equipped with normal papermaking process components, such as headbox, forming wire, and continuous dryer) at a rate of about 80 l/min. The paper machine is operated at the production speed of 200 m/min.
The latex content of the final paper products can be measured by x-ray fluorescence analysis. The analysis is done by brominating the unsaturated double bonds of a styrene-butadiene rubber component of the latex and then measuring the x-ray fluorescence intensity. The estimated latex add-on level for the sample measured by this method is on the order of 11-12%. The wet strength of the latex-containing paper product produced by a continuous pilot paper machine can be determined by measuring the tensile strength required to tear a one-inch-wide strip of paper product after the sample is soaked in water.
The following Example illustrates the preparation of paper-type sheets comprising a polycationic wet-strength agent and a polyanionic absorbent gelling material.
EXAMPLE VIII
Preparation of Superabsorbent Layered Handsheet Paper
Two separate slurries are prepared comprising 1.06 g (1.0 g dry wt.) 40% wt. unrefined NSK pulp in 250 ml distilled water, adjusted to pH 8.5 (0.1N sodium hydroxide).
The polycationic latex of Example I (0.652 g) is added to each of the two NSK/water slurries and stirred for 30 minutes.
0.5 G of commercial SANWET (acrylate-starch graft) absorbent gelling material is prepared as a fine powder.
Each separate slurry is formed on the Deckle Box in distilled water at pH 8.5 and placed on a transfer fabric in the following order: top layer NSK sheet; middle layer powdered SANWET; bottom layer NSK sheet.
The layered sheet is transferred via a vacuum slit to a transfer sheet to form the finished paper handsheet. The finished handsheet is passed over a high vacuum twice and a second transfer sheet is placed on top of the finished sheet. The resulting sheet is passed over a drum dryer (155° C.) 10-12 times, until dry.
EXAMPLE VIX
The procedure of Example I is repeated, but the styrene/butadiene monomer mixture is replaced by the following: styrene/isoprene (1:1 wt.); isoprene; and ethylene, respectively. | Polycationic wet-strength materials such as KYMENE are chemically modified to provide unsaturated hydrocarbon substituents. The modified KYMENE is cross-linked onto and into latex particles to provide improved wet-strength agents for use in paper treatments. Thus, KYMENE is reacted, for example, with acrylic acid and cross-linked with styrene/butadiene to provide a polycationic latex wet-strength agent. | 3 |
There are no related patent applications.
This application did not receive federal research and development funding.
BACKGROUND OF THE INVENTION
The present invention generally relates to a system and method which allows for the safe disposal of unexploded underwater ordnance, like bombs, projectiles and mines. More particularly, the invention relates to a remotely controlled system comprised of a remote controller, a floating transceiver including an antenna that receives remote control signals from the remote controller and provides control signals through a tether to an underwater hydraulic grapple, and an ordnance recovery basket. The floating transceiver further includes a power source such as a generator or battery set for providing power for operating the hydraulic grapple to retrieve ordnance from the bottom of a body of water.
“Knucklebooms” or hydraulic grapples are used commercially in the logging industry to load cut logs onto transportation devices such as trucks and railroad cars. Outside of the logging and construction industries, however, grapples are rarely used.
There are many offshore sites around the world that have served as dumping grounds for unexploded ordnance, such as mines, bombs, projectiles, and bulk containers holding chemical weapons filler material. At ammunition handling facilities where the draft of the vessel exceeds the working depth of the port, weapons must be unloaded at sea. Cargo handling mishaps result in the sea floor surrounding many ports being laden with undetonated bombs, creating both safety issues and environmental hazards.
Moreover, some coastal areas, open ocean, and inland bodies of waters have formerly been subjected to long term use as “live fire impact areas,” for training and weapons development. This has resulted in high concentrations of unexploded ordnance in areas which are today sought for recreational use and commercial development.
The present invention incorporates for the first time the use of a remotely controlled grapple, capable of functioning underwater and directed via a remote controller, to dispose of submerged ordnance by first depositing it into a recovery basket to create a safe, non-explosive way of clearing an ocean floor of the explosives. The present invention also claims a method for disposing of unexploded underwater ordnance.
SUMMARY OF THE INVENTION
The invention, a remotely operated, underwater non-destructive ordnance recovery system, provides a new an unique way of removing underwater ordnance by utilizing a multi-part system operated by remote control. The system comprises a remote controller that is located remote from an underwater grappling unit. The grappling unit is deposited onto the bottom of a body of water in an area that is saturated with unexploded ordnance. An antenna platform floats on a surface of the water and may include a power source. The antenna receives control signals from the remote controller. These control signals cause a plurality of valves in the grappling unit to be opened or closed. Each valve directs a flow of fluid through an associated piston to extend, retract or cause the piston to assume a neutral operation. By extending and retracting the pistons, the grapple may be manipulated to grip unexploded ordnance. The unexploded ordnance is then raised to the surface of the water.
The system contains a remote controller having a first plurality of switches that produce control signals which are wirelessly transmitted to a remote antenna to cause the grappling unit to be leveled. A second plurality of switches controls movements of a boom to raise and lower a base boom element and an end boom element to cause a grapple attached at an end of the end boom element to be extended away from the grapple unit. A further switch causes the boom to rotate relative to the outriggers attached to a base of the grapple unit. A third plurality of switches produce control signals that manipulate the jaws of the grapple to open, close, rotate and lock. A fourth keyed locking switch control operation of the remote controller. The remote controller includes an antennae capable of sending the remote controlled signals a minimum distance of 600 feet. Monitors display a remote video feed from cameras located on the grapple unit.
The system also contains a floating transceiver comprised antennae for receiving signals from the remote controller, a power source, and a control head. The control head includes a decoder for decoding the control signals transmitted from the remote controller. The decoded control signals are routed to pulse width modulators to produce signals that control the flow of fluid through the pistons. The control head converts electronic signals from the remote controller into the actuation of hydraulic valves in a closed loop hydraulic system driven by an internal electrically powered pump, thereby controlling the motion of the knuckleboom. Located on both the control box and on either side of the ballast tubes are lighted underwater cameras which transmit images to the control station.
Tethered to the transceiver by a control cable is the grappling unit. The grappling unit is typically capable of moving ordnance from 500-2000 lbs., depending on the length of extension of the boom. The grappling unit comprises a base stabilized by three or four remotely adjustable legs. The adjustable legs act as outriggers that may be manipulated to maintain the base in a level manner or at a desired angle. Feet attached to the adjustable legs contact the bottom of the body of water. The feet may be of various sizes and shapes and are readily removable and replaceable for accommodating different bottom surfaces. The control head receives signals via the control cable and transfers those signals into hydraulic value actuation to manipulate the jaws arranged at the end of the boom. The end boom element includes two ballast tubes which stabilize the unit at maximum extension. Typically the grapple jaws are capable of picking ordnance having a diameter of no less than three inches and no larger than forty-eight inches. Located on both the control box and on either side of the ballast tubes are lighted underwater cameras which transmit images to the control station. The grapple motion is powered by an electrically driven internal hydraulic pump which circulates a bio-degradable hydraulic fluid, such as vegetable oil, through a closed loop system.
The system contains a submergible ordnance recovery basket defining an cavity capable of holding unexploded ordnance. This recovery basket comprises wire mesh sides and top and includes a rigid floatation cylinder that includes an input port for receiving pressurized air and a pressure relief valve for controlling ascent of the recovery basket when raising it to the water surface. The basket is tethered to a surface buoy by a fixed bail attached to the basket. The lower portion of the basket, the receptacle, has a spring loaded entry door for ordnance on one side and a hinged prop door on the other side. The upper portion of the basket, the cylinder, has, on the spring loaded entry door side, attached self locking latches and an armor kick plate for deflecting ordnance downward when it enters the receptacle. On both sides of the basket are located compressed air cylinders which release air through a connective tube into the cylinder to raise the basket to the surface. So that the basket raises at a steady speed, pre-set, automatic pressure relief valves are located on both sides of the cylinder. Pre-set sonic valves are located on each connective tube to allow a set amount of air to be released from the cylinder uniformly to rises the basket at a steady speed. One door is for depositing ordnance in the recovery basket; the other door is located on an opposite side and is opened to allow the ordnance to be dropped from the recovery basket. Compressed air is stored in storage tanks on either side of the recovery basket and includes remotely actuated valves such sonic valves for releasing air from the storage tanks and directing it into the rigid floatation cylinder. Self locking latches are provided for securing the loading door.
An object of the invention is to enable the user to safely move underwater unexploded ordnance from the seafloor to a location where it can be safely stored or detonated with as little harm to the environment and wildlife as possible.
A further object of the invention is to enable the user to safely clear large areas of underwater unexploded ordnance from a bottom of a body of water.
A further object of the invention is to enable the user to safely move underwater unexploded ordnance from the seafloor without the assistance of a human diver.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned from practicing the invention. The objects and advantages of the invention will be obtained by means of instrumentalities in combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of an underwater, unexploded ordnance removal system.
FIG. 2A is a plan view of a remote controller reflecting the various switches that control a remote underwater, unexploded ordnance removal grapple mechanism. FIG. 2B is a schematic view of the remote controller.
FIG. 3 is an enlarged view of a control station shown in FIG. 1 .
FIG. 4A is first perspective view of the remote underwater, unexploded ordnance removal grapple mechanism. FIG. 4B is a second perspective view of the remote underwater, unexploded ordnance removal grapple mechanism. FIG. 4C is a perspective view of the floating antenna and power supply.
FIG. 5 is a close up perspective view of the grapple.
FIGS. 6A-6D show schematic views of the control unit attached to the remote underwater, unexploded ordnance removal grapple mechanism.
FIGS. 7A-7F depict perspective views of the recovery basket in various positions.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment is shown in FIG. 1 . The system 1 includes an operator station 7 that is remote from an ordnance disposal unit 61 . An enlarged view of the operator station is shown in FIG. 3 and includes a display 5 that comprises a receiver and displays video feeds from lighted cameras on the disposal unit 61 . A remote controller 3 is arranged in easy reach of an operator. In FIG. 1 , the operator station is arranged in a boat 11 . An antenna 9 receives control signals from the remote controller 3 and transmits these signals to the floating transceiver 41 which comprises a second antenna 43 . These signals are relayed from the floating transceiver 41 to the disposal unit 61 via cable 42 . In this manner, the operator may view the display 5 and manipulate the remote controller 3 to cause the disposal unit 61 to grip ordnance 100 and lift it from a sea floor or lake bottom. The disposal unit 61 thereafter rotates to swing the ordnance 100 and deposit it into a basket 25 . The basket 25 is coupled to a float 21 via retrieval cable 23 . The float 21 may be pulled to a designated area where the basket 25 may be emptied.
FIG. 2A is a plan view of the remote controller 3 that comprise a plurality of switches 11 - 23 . A first plurality of switches 12 - 15 create control signals that extend and retract legs 66 to level disposal unit 61 . These switches are neutrally biased toggle switches that may be force in opposite directions to create control signals. Switches 12 and 14 control the respective operation of a front and rear leg for raising the respective areas of the base. Switches 13 and 15 control the respective operation of left and right legs in the same manner to level the base of the disposal unit 61 .
The remote controller 3 comprises a second plurality of switches 16 - 18 which are also neutrally biased toggle switches that may be forced into a opposite directions to control the various operations of the boom. Switch 16 raises and lowers a base boom element that is coupled to the base of the disposal unit 61 . Switch 17 raises and lowers an end boom element that is coupled to the base boom element on one end and to a grapple at the other end. Switch 18 rotates the boom relative to the base.
A third plurality of switches 19 , 20 , 22 and 23 control the operation of the jaws that comprise the grapple. Switch 19 rotates the jaws relative to the end boom element. Switch 22 tilts the jaws relative to the end boom element. Switch 23 provides control signals that cause the jaws to be opened or closed. When engaged, switch 20 locks the jaws after they grip the ordnance 100 to prevent an inadvertent dropping of them.
The remote controller 3 is also equipped with a key lock 11 similar to an automobile ignition switch that prevents unauthorized use of the disposal unit. A key (not shown) must be inserted into the key lock 11 and the key lock twisted to allow power to flow from a power source (shown in FIG. 2B ) to the remote controller in order for the remote controller 3 to be operated. Without the key, operation of the remote controller 3 is prohibited. An emergency stop switch 21 quickly shuts down the disposal unit if an emergency condition arises.
FIG. 2B is a simplified schematic of the remote controller 3 . A power source 30 is coupled to the 11 . Without first turning key switch 11 on, the remote controller cannot produce control signals to be relayed to the remote disposal unit 61 . The switches 12 - 23 are prohibited from operating when the key switch is in an off position. Each switch is connected to an encoder for producing a control signal associated with a respective valve on the disposal unit 61 . These signals are then routed to a transmitter and transmitted via antenna 9 .
FIG. 3 is an enlarged view of operator station 7 shown in FIG. 1 . The operator station 7 comprises a chair 30 that includes a plurality of legs 31 arranged beneath the chair 30 . An arm 32 extends from the chair 7 and includes a rack 33 for accommodating data storage devices 34 for recording the video signal shown on display 5 .
FIGS. 4A and 4B are different perspective views of the remote controlled disposal unit 61 . For ease in understanding the invention, all hydraulic lines or hoses that transport fluid from the control head to the pistons are labeled as 77 . It should be noted that the bi-directional valves used in the present invention allow for the fluid to flow a direction from the pump to the piston and from the piston back to the reservoir from which the pump draws a source of fluid. Likewise, the piston may be arranged to have a hydraulic line entering opposite ends to drive the piston towards either an extended or retracted position.
The remote disposal unit 61 includes a boom 69 that comprises a base boom element 73 and an end boom element 71 . One end of the base boom element 73 rotateably connects to the base 62 . The base 62 includes a control head 90 to which one end of hydraulic lines 77 connect thereto. An opposite end of each hydraulic line 77 connects to a respective piston. A foot 63 attaches at each free end of each retractable leg 66 . The pistons 64 may be extended or retracted to cause the lowering and raising of their respective leg. Since the feet are settled on the bottom, this movement in turn is transmitted to the base 62 . Control signals produced by switches 12 - 15 of remote controller 3 control the position of various valves in the control head 90 to cause the extension and retraction of respective legs 66 .
As previously mentioned, the base 62 includes a rotation element 79 that allows the boom 69 to swing a grapple 55 in an arc relative to the legs 66 . This rotation element works similar to the pistons in that fluid may be forced into the rotation element 79 in a first direction to swing the boom 69 and grapple 55 counterclockwise. When fluid is forced into the rotation element 79 in an opposite direction, the boom 69 and grapple 55 spin clockwise about the base 62 . The direction of the flow of fluid is controlled by switch 18 shown in FIG. 2A .
The boom 69 attaches above the rotation element 79 and comprises a base boom element 73 and an end boom element 71 to which grapple 55 attaches. A piston 74 causes a free end of the base boom element 73 to be raised and lowered. This free end is pivotally coupled to one end of the end boom element 71 . A piston 72 attaches between the base boom element 73 and the end boom element 71 to cause the end boom element 71 to be rotated about the free end of the base boom element 73 . Hydraulic hoses 77 connect to each of the pistons 73 , 74 and pressure in each is controlled by a valve located in the control head 90 and being controlled by the associated switches 16 , 17 .
A pair of ballasts 83 are arranged atop the end boom element 71 to assist in stabilizing the disposal unit 61 when it is operating at with the boom at maximum extension. A camera 84 is coupled to the base unit 62 , as shown. Two lighted cameras 85 are arranged along the end boom element 71 and wirelessly transmit a real time video signal back to the display 5 . Jaws 76 A and 76 B grip ordnance 100 in FIG. 4A .
FIG. 4C is a perspective view of a floating transceiver that includes a horn 600 informing others when the system is in operation. The floating transceiver includes a generator for supplying power to the remote disposal unit 61 . A receiver repeater box 401 receives signals from remote controller 3 and relays them to the control box 90 . Engine 402 propels the floating transceiver 41 to a remote location where the ordnance is located.
FIG. 5 is an enlarged view of the grapple 55 . The grapple 55 includes a pair of jaws 76 A, 76 B that are coupled to one end of a rotation element 80 . The rotation element 80 may includes a plurality of hoses that are associated with the switches 19 , 20 , 21 , 23 . The rotation element 80 may rotate the grapple relative to the free end of the end boom element 71 and in accord with a control signal produced by switch 19 . The rotation element 80 may also tilt the jaws and open or close the jaws in accordance with input control signals produced by the associated switches.
FIGS. 6A through 6D are schematic views of a control head 90 that connects to the floating transceiver 41 via cable 42 . A power supply 120 is either provided in way of a generator or battery source aboard the floating transceiver 41 . Alternatively, the power supply 120 may be provided in the control box 90 . A power distribution point such as a panel, box or board 121 comprises a plurality of connectors, labeled X 1 through X 4 . These connectors accept power from the power supply and thereafter distribute the power to the associated logic circuits, switches, valves, and pump.
The power distribution board 121 routes power to a relay 122 that operates as an emergency stop switch to cut power to the various hydraulic valves and pump in the event of an emergency. This relay 122 opens to prevent power from flowing to the valves when switch 21 is activated. The opening of the relay 122 prevents any operation of any of the remote disposal unit 61 .
Power from the relay 122 is directed to a plurality of pulse width modulators (PWM) 124 , 125 , 126 , 128 . These modulators receive control signals from a decoder 129 to produce control signals for the various valves that direct a direction of fluid flowing through the various pistons shown in FIG. 6D . A relay 123 also receives signals that are relayed to the PWMs for controlling the various states of the valves. That is the relay 123 turns the various valves on and off; whilst the output signals from the PWMs to the valves control the direction of fluid, amount and duration of fluid flow through each piston. The relay 123 also provides power to a horn to signal the start up of the signal. The horn may be arranged on the floating transceiver. The connectors, X 1 through X 4 , accepts power from the power supply and thereafter distributes the power to the associated logic circuits, switches, valves, and pump. First and second relays are provided for providing a signal to allow the outriggers to be deployed in a manner to level the remote controlled unit. First and second jaw select relays provide a signal that allows the various functions of the jaws to be realized. A dump valve relay causes the pressure of the pump to be quickly reduced such that a movement of the remote controlled unit may be quickly ceased.
PWMs 124 , 125 control the functions of the leveling of the base of the remote disposal unit 61 through pistons 64 A through 64 D. Control of the boom 69 is also provided by the control signals produce by PWM 124 . The various PWMs receive remote control signals and processing them into signals to be used by the bi-directional valves that control the various functions associated with the receiver. PWMs 126 , 128 provides control signals for actuating the boom and its respective functions. A receiver 130 is coupled to an antenna on the floating transceiver unit and receives signals from the transmitter of the remote controller. Decoder 129 receives control signals that are produced by the various switches of FIG. 2A . These control signals are processed to convert them into signals for controlling the relays and PMWs for controlling the valves. The receiver is coupled to an antenna that is located on the surface of the body of water. The receiver receives a signal that is transmitted from the remote controller and relays this signal to the decoder for signal processing. A waterproof connector is supplied in a side of the waterproof housing that surrounds the receiver assembly. An antenna is coupled to the waterproof connector via a signal cable that includes a complementary connector that mates with the waterproof connector in the side of the waterproof housing.
Now referring to FIGS. 7A through 7F which depict the ordnance disposal basket 25 . Basket 25 comprises sides and an end formed from steel mesh. This is particularly useful in preventing destruction of the basket 25 should ordnance 100 prematurely detonate. The basket includes a fixed bail 400 formed of rigid material such as steel. Self-locking hatches 401 secure a spring loaded entry door 402 via couplers 404 . A rigid floatation cylinder 408 receives pressurized air from compressed air cylinders 406 . A pressure relief valve 407 assures that the basket is raised to the surface 300 in a uniform manner.
As shown in FIG. 7A , the basket 25 is initially deposited onto the bottom 301 of the body of water with door 402 in an open position. Ordnance 100 is loaded into basket 25 and door 402 is closed. Sonic valves connect between compressed air cylinders 406 such that they are actuated to cause air to flow from the cylinders 406 into cylinder 408 . This in turn causes the front of the basket 25 to be raised from the bottom of the water 301 , as shown in FIG. 7C . Either the float 21 or the cable tether 23 is caught and the basket 25 is towed as shown in FIG. 7D . When the basket reaches a predetermined dumping area, a second door 420 is opened to dump ordnance 100 from the basket. As ordnance 100 is dumped, the cylinder 408 assumes a higher place on the water surface as shown in FIG. 7F .
While the invention has been described with respect to preferred embodiments, 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 limiting sense. From the above disclosure of the general principles of the present invention and the preceding detailed description, those skilled in the art will readily comprehend the various modifications to which the present invention is susceptible. Therefore, the scope of the invention should be limited only by the following claims and equivalents thereof. | A remote operated, underwater non-destructive ordnance recovery system, includes a powered remote controller, a floating remote controlled transceiver wired to a remote disposal unit having a hydraulic grapple, an ordnance recovery basket, and the method in which these devices are used to extract unexploded underwater ordnance. The remote disposal unit includes an electrically driven internal hydraulic pump with bio-degradable hydraulic fluid in a closed loop system. A base includes variable footplates to stabilize the hydraulic grapple by remotely adjustable telescoping legs. A control head that receives signals from control cables and transfers them into hydraulic value actuation, an extendable fully rotating boom, two ballast tubes, a rotating grapple, and lighted underwater cameras on the control box and ballast tubes are also included in remote disposal unit. | 1 |
REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application Ser. No. 60/064,937 filed Nov. 7, 1997.
FIELD OF THE INVENTION
The present invention relates to novel phenyl-alkyl-imidazoles having valuable pharmacological properties, especially CNS activities and activity against inflammatory disease. Compounds of this invention are antagonists of the H 3 receptor.
BACKGROUND OF THE INVENTION
European Patent Application No. 0 420 396 A2 (Smith Kline & French Laboratories Limited) and Howson et al., Bioorg. & Med. Chem. Letters, Vol. 2 No. 1 (1992), pp. 77-78 describe imidazole derivatives having an amidine group as H 3 agonists. Van der Groot et al. (Eur. J. Med. Chem. (1992) Vol. 27, pp. 511-517) describe isothiourea analogs of histamine as potent agonists or antagonists of the histamine H 3 receptor, and these isothiourea analogs of histamine overlap in part with those of the two references cited above. Clapham et al. ["Ability of Histamine H 3 Receptor Antagonists to improve Cognition and to increase Acetylcholine Release in vivo in the Rat", British Assn. for Psychopharmacology, Jul. 25-28 1993, reported in J. Psychopharmacol. (Abstr. Book), A17] describe the ability of histamine H 3 receptor antagonists to improve cognition and to increase release of acetylcholine in vivo in the rat. Clapham et al. ["Ability of the selective Histamine H 3 Receptor Antagonist Thioperamide to improve Short-term Memory and Reversal Learning in the Rat", Brit. J. Pharm. Suppl., 1993, 110, Abstract 65P] present results showing that thioperamide can improve short-term memory and reversal learning in the rat and implicate the involvement of H 3 receptors in the modulation of cognitive function. Yokoyama et al. ["Effect of thioperamide, a histamine H 3 receptor antagonist, on electrically induced convulsions in mice", Eur. J. Pharmacol., vol. 234 (1993), pp. 129-133] report how thioperamide decreased the duration of each phase of convulsion and raised the electroconvulsive threshold, and go on to suggest that these and other findings support the hypothesis that the central histaminergic system is involved in the inhibition of seizures. International Patent Publication No. WO9301812-A1 (SmithKline Beecham PLC) describes the use of S-[3-(4(5)-imidazolyl)propyl]isothiourea as a histamine H 3 antagonist, especially for treating cognitive disorders, e.g. Alzheimer's disease and age-related memory impairment. Schlicker et al. ["Novel histamine H 3 receptor antagonists: affinities in an H 3 receptor binding assay and potencies in two functional H 3 receptor models"] describe a number of imidazolylalkyl compounds wherein the imidazolylalkyl group is bonded to a guanidine group, an ester group or an amide group (including thioamide and urea), and compare these to thioperamide. Leurs et al. ["The histamine H 3 -receptor: A target for developing new drugs", Progr. Drug Res. (1992) vol.39, pp.127-165] and Lipp et al. ["Pharmacochemistry of H 3 -receptors" in The Histamine Receptor, eds.: Schwartz and Haas, Wiley-Liss, New York (1992), pp.57-72] review a variety of synthetic H 3 receptor antagonists, and Lipp et al. (ibid.) have defined the necessary structural requirements for an H 3 receptor antagonist.
WO 95/14007 claims H 3 receptor antagonists of the formula ##STR2## wherein A is selected from --O--CO--NR 1 --, --O--CO--, --NR 1 --CO--NR 1 --, --NR 1 --CO--, --NR 1 --, --O--, --CO--NR 1 --, --CO--O--, and --C(:NR 1 )--NR 1 --;
the groups R 1 , which may be the same or different when there are two or three such groups in the molecule of formula I, are selected from hydrogen, and lower alkyl, aryl, cycloalkyl, heterocyclic and heterocyclylalkyl groups, and groups of the formula --(CH 2 ) y --G, where G is selected from CO 2 R 3 , COR 3 , CONR 3 R 4 , OR 3 , SR 3 , NR 3 R 4 , heteroaryl and phenyl, which phenyl is optionally substituted by halogen, lower alkoxy or polyhaloloweralkyl, and y is an integer from 1 to 3;
R 2 is selected from hydrogen and halogen atoms, and alkyl, alkenyl, alkynyl and trifluoromethyl groups, and groups of the formula OR 3 , SR 3 and NR 3 R 4 ;
R 3 and R 4 are independently selected from hydrogen, and lower alkyl and cycloalkyl groups, or R 3 and R 4 together with the intervening nitrogen atom can form a saturated ring containing 4 to 6 carbon atoms that can be substituted with one or two lower alkyl groups;
with the proviso that, when y is 1 and G is OR 3 , SR 3 or NR 3 R 4 , then neither R 3 nor R 4 is hydrogen;
the group --(CH 2 ) n --A--R 1 is at the 3- or 4-position, and the group R 2 is at any free position;
m is an integer from 1 to 3;
and n is 0 or an integer from 1 to 3;
or a pharmaceutically acceptable acid addition salt thereof;
or a pharmaceutically acceptable salt thereof with a base when G is CO 2 H; including a tautomeric form thereof.
U.S. application Ser. No. 08/689951 filed Aug. 16, 1996 (now abandoned) and U.S. application Ser. No. 08/909319 filed Aug. 14, 1997 (now U.S. Pat. No. 5,869,479 issued Feb. 9, 1999) disclose compositions for the treatment of the symptoms of allergic rhinitis using a combination of at least one histamine H 1 receptor antagonist and at least one histamine H 3 receptor antagonist.
In view of the art's interest in compounds which affect the H 3 receptors, novel compounds having antagonist activity on H 3 receptors would be a welcome contribution to the art. This invention provides just such a contribution by providing novel compounds having H 3 antagonist activity.
SUMMARY OF THE INVENTION
The present invention provides a compound of the formula I ##STR3## or a pharmaceutically acceptable salt or solvate thereof, wherein: the double bond (a) is E or Z (that is the double bond to the carbon atom having the R 15 substituent is of the E or Z configuration);
each R 1 is independently selected from the group consisting of hydrogen, lower alkyl, trihalomethyl, phenyl and benzyl;
each R 7 is independently selected from the group consisting of hydrogen, lower alkyl, halogen, trihalomethyl, NR 10 R 11 , or a group OR 10 , whereby R 10 and R 11 are independently selected from hydrogen, lower alkyl or trihalomethyl;
X is --CONR 5 --; --SO 2 --, --S--; --CO--; --COO--; --CN(OR 5 )NR 5 --; --C(NR 5 )NR 5 --; --SONR 5 --; --SO 2 NR 5 -- and, provided p is not zero, X may also be --O--; --NR 5 --; --NR 5 CONR 5 --; --OCONR 5 --; --O--CO-- or --NR 5 CO--;
Y is C 1 -C 3 -alkyl, optionally substituted at any carbon atom of the group by one substituent R 5 ;
Z is C(R 1 ) 2 ; wherein no more than two R 1 groups are other than hydrogen;
n is 1 or 2;
m is 0 or 1;
p is 0 or 1;
q is 0 or 1;
R is selected from C 3 to C 7 cycloalkyl, heterocyclic groups, aryl or heteroaryl, wherein said R groups are optionally substituted with 1-3 substituents as defined below;
each R 5 independently represents hydrogen, lower alkyl or poly-haloloweralkyl; and
R 15 represents H or lower alkyl (e.g., methyl).
A further feature of the invention is pharmaceutical compositions containing as active ingredient a compound of the formula I defined above (or a salt, or a solvate, or tautomer) together with a pharmaceutical carrier or excipient.
Further features of the invention are methods for treating inflammation, allergy, diseases of the GI-tract, cardiovascular disease, or disturbances of the central nervous system, which comprise administering to a patient suffering from the corresponding disease (i.e., a patient in need of such treatment) an effective amount of a compound of the formula I defined above (or a salt, solvate or tautomer thereof). For example, a feature of this invention is a method of treating allergy, inflammation, hypotension, glaucoma, sleeping disorders, states of hyper and hypo motility of the gastrointestinal tract, hypo and hyperactivity of the central nervous system, Alzheimer's, schizophrenia, obesity and migraines, comprising administering an effective amount of a compound of formula I (or a salt, solvate or tautomer thereof) to a patient in need of such treatment.
Another feature of this invention is a method for treating inflammation, which comprises administering to a patient suffering from inflammation an effective amount of a compound of formula I (or a salt, solvate or tautomer thereof) to a patient in need of such treatment.
Another feature of this invention is a method for treating allergy, which comprises administering to a patient suffering from allergy an effective amount of a compound of formula I (or a salt, solvate or tautomer thereof) to a patient in need of such treatment.
Another feature of this invention is a method for treating diseases of the GI-tract, which comprises administering to a patient suffering from a disease of the GI-tract an effective amount of a compound of formula I (or a salt, solvate or tautomer thereof) to a patient in need of such treatment.
Another feature of this invention is a method for treating cardiovascular disease, which comprises administering to a patient suffering from cardiovascular disease an effective amount of a compound of formula I (or a salt, solvate or tautomer thereof) to a patient in need of such treatment.
Another feature of this invention is a method for treating disturbances of the central nervous system, which comprises administering to a patient suffering from disturbances of the central nervous system an effective amount of a compound of formula I (or a salt, solvate or tautomer thereof) to a patient in need of such treatment.
The invention also includes the aspect of using the compounds of formula I in combination with a histamine H 1 receptor antagonist for treatment of allergy-induced airway (e.g., upper airway) responses.
DETAILED DESCRIPTION OF THE INVENTION
Compounds of the formula I can exist in tautomeric forms by virtue of the imidazole ring: the N-hydrogen atom can tautomerize from one nitrogen atom to the other of that ring. When q is 1 and Y is a substituted alkyl group, or when one R 1 substituent of each (Z) n group is other than H, the compounds of formula I will have asymmetric carbon atoms and will exist in different forms due to such chiral center. All such isomers including diastereomers and enantiomers are covered by the invention.
The compounds of the invention are basic and form pharmaceutically acceptable salts with organic and inorganic acids. Examples of suitable acids for such salt formation are hydrochloric, sulfuric, phosphoric, acetic, citric, oxalic, malonic, salicylic, malic, fumaric, succinic, ascorbic, maleic, methanesulfonic and other mineral and carboxylic acids well known to those skilled in the art. The salts are prepared by contacting the free base form with a sufficient amount of the desired acid to produce a salt in the conventional manner. The free base forms may be regenerated by treating the salt with a suitable dilute aqueous base solution such as dilute aqueous sodium hydroxide, potassium carbonate, ammonia and sodium bicarbonate. The free base forms differ from their corresponding salt forms somewhat in certain physical properties, such as solubility in polar solvents, but the salts are otherwise equivalent to their corresponding free base forms for purposes of this invention.
The compounds of Formula I can exist in unsolvated as well as solvated forms, including hydrated forms, e.g., hemi-hydrate. In general, the solvated forms, with pharmaceutically acceptable solvents such as water, ethanol and the like are equivalent to the unsolvated forms for purposes of the invention.
Numerous chemical substances are known to have histamine H 1 receptor antagonist activity. Many useful compounds can be classified as ethanolamines, ethylenediamines, alkylamines, phenothiazines or piperidines. Representative H 1 receptor antagonists include, without limitation: astemizole, azatadine, azelastine, acrivastine, brompheniramine, cetirizine, chlorpheniramine, clemastine, cyclizine, carebastine, cyproheptadine, carbinoxamine, descarboethoxyloratadine (also known as SCH-34117), diphenhydramine, doxylamine, dimethindene, ebastine, epinastine, efletirizine, fexofenadine, hydroxyzine, ketotifen, loratadine, levocabastine, mizolastine, mequitazine, mianserin, noberastine, meclizine, norastemizole, picumast, pyrilamine, promethazine, terfenadine, tripelennamine, temelastine, trimeprazine and triprolidine. Other compounds can readily be evaluated to determine activity at H 1 receptors by known methods, including specific blockade of the contractile response to histamine of isolated guinea pig ileum. See for example, WO98/06394 published Feb. 19, 1998.
For example, the H 3 antagonists of this invention can be combined with an H 1 antagonist selected from astemizole, azatadine, azelastine, brompheniramine, cetirizine, chlorpheniramine, clemastine, carebastine, descarboethoxyloratadine (also known as SCH-34117), diphenhydramine, doxylamine, ebastine, fexofenadine, loratadine, levocabastine, mizolastine, norastemizole, or terfenadine.
Also, for example, the H 3 antagonists of this invention can be combined with an H 1 antagonist selected from, azatadine, brompheniramine, cetirizine, chlorpheniramine, carebastine, descarboethoxyloratadine (also known as SCH-34117), diphenhydramine, ebastine, fexofenadine, loratadine, or norastemizole.
Representative combinations include: the H 3 antagonists of this invention with loratadine, H 3 antagonists of this invention with descarboethoxyloratadine, H 3 antagonists of this invention with fexofenadine, and H 3 antagonists of this invention with cetirizine.
Those skilled in the art will know that the term "upper airway" means the upper respiratory system--i.e., the nose, throat, and associated structures.
When used herein, unless indicated otherwise, the following terms have the given meanings:
lower alkyl (including the alkyl portions of lower alkoxy)--represents a straight or branched, saturated hydrocarbon chain having from 1 to 6 carbon atoms, preferably from 1 to 4;
aryl--represents a carbocyclic group having from 6 to 14 carbon atoms and having at least one benzenoid ring, with all available substitutable aromatic carbon atoms of the carbocyclic group being intended as possible points of attachment, said carbocyclic group being optionally substituted with 1 to 3 groups, each optional substituent being independently selected from the group consisting of lower alkyl, halogen, trihalomethyl, CN, NO 2 , OR 10 or NR 10 R 11 , wherein R 10 and R 11 are independently selected from hydrogen, lower alkyl or trihalomethyl; preferred aryl groups include 1-naphthyl, 2-naphthyl and indanyl, and especially phenyl and substituted phenyl;
cycloalkyl--represents a saturated carbocyclic ring having from 3 to 8 carbon atoms, preferably 5 or 6, optionally substituted by 1 to 3 groups independently selected from the group consisting of lower alkyl trihalomethyl and NR 10 R 11 , wherein R 10 and R 11 are independently selected from hydrogen, lower alkyl or trihalomethyl; said cycloalkyl group optionally being fused to an aryl ring (e.g., phenyl), e.g., cyclohexyl fused to phenyl;
heterocyclic--represents saturated and unsaturated non-aromatic cyclic organic groups having at least one O, S and/or N atom interrupting a carbocyclic ring structure that consists of one ring or two fused rings, wherein each ring is 5-, 6- or 7-membered, which ring structure has from 2 to 8, preferably from 3 to 6 carbon atoms; e.g., 2- or 3-pyrrolidinyl, 2-, 3- or 4-piperidinyl, 2- or 3-piperazinyl, 2- or 3-morpholinyl, or 2- or 3-thiomorpholinyl; said heterocyclic group being optionally substituted by 1 to 3 groups independently selected from the group consisting of lower alkyl, trihalomethyl, and NR 10 R 11 , wherein R 10 and R 11 are independently selected from hydrogen, lower alkyl or trihalomethyl, said substituents being bound to carbon atoms (substitutable carbon atoms) in the ring such that the total number of substituents in the ring is 1 to 3; and wherein said heterocyclic ring contains nitrogen atoms, said nitrogen atoms (i.e., the substitutable nitrogen atoms) being optionally substituted with lower alkyl (e.g., alkyl), e.g., 1-N-methylpyrrolidinyl;
halogen--represents fluorine, chlorine, bromine and iodine; and
heteroaryl--represents a cyclic organic group having at least one O, S and/or N atom interrupting a carbocyclic ring structure and having a sufficient number of delocalized pi electrons to provide aromatic character, with the aromatic heterocyclic group having from 2 to 14, preferably 4 or 5 carbon atoms, e.g., indolyl, 2-, 3- or 4-pyridyl, 2- or 3-furyl, 2- or 3-thienyl, 2-, 4- or 5-thiazolyl, 2- or 4-imidazolyl, 2-, 4- or 5-pyrimidinyl, 2-pyrazinyl, or 3- or 4-pyridazinyl, and the like; preferred heteroaryl groups are 2-, 3- and 4-pyridyl; said heteroaryl groups being optionally substituted with 1 to 3 groups, each optional substituent being independently selected from the group consisting of lower alkyl, halogen, trihalomethyl, CN, NO 2 , OR 10 or NR 10 R 11 , wherein R 10 and R 11 are independently selected from hydrogen, lower alkyl or trihalomethyl, said substituents being bound to carbon atoms (substitutable carbon atoms) in the ring such that the total number of substituents in the ring is 1 to 3.
Compounds of this invention are antagonists of the H 3 receptor. As such, they may be useful for the treatment of various allergic, inflammatory, GI-tract, or cardiovascular diseases. In addition, they possess CNS activity; they may be useful as sleep regulators, anticonvulsants, cognition enhancers, antidepressants, regulators of hypothalamo-hypophyseal secretions, and the like.
Compounds of formula I include those compounds wherein R 1 is H.
Compounds of formula I also include compounds wherein n is 1.
Compounds of formula I further include compounds wherein R 1 is H and n is 1.
Compounds of formula I additionally include compounds wherein wherein R 1 is H, R 7 is H, and n is 1.
In addition, compounds of formula I include compounds wherein R 15 is hydrogen.
Preferred compounds of formula I are compounds of the formulae II, III, IV, V, VI, and VII described below. ##STR4## wherein R 1 , R 7 , R, Y, Z, (a), m, n, p and q are as defined for formula I.
R 1 , R 7 and R 15 are hydrogen. More preferably, n is 1, and R 1 , R 7 and R 15 are hydrogen. Particularly preferred are those compounds wherein n is 1, and R 1 , R 7 and R 15 are hydrogen, and R is phenyl, pyridyl, substituted phenyl or substituted pyridyl. The preferred substituents in said phenyl or pyridyl groups are halogen, preferably chlorine or fluorine, methoxy, trifluoromethyl, CN or trifluoromethoxy. Preferably there are one or two of said substitutents, and each substituent is independently selected.
For compounds of formula II, m is preferably 0. Most preferred are those compounds of formula II wherein m and p are both 0; q is 0 or 1, and, when q=1, Y is --CHR 5 CHR 5 -with one R 5 being hydrogen and the other as defined for R 5 above. For formulae III and IV m is preferably 0 or 1, p is 1 or 2 and q is 0. For all the above groups of compounds the preferred meaning of R is phenyl or phenyl substituted by one or two of the substituents described above in the definition of aryl. The most preferred substituents are CN, chlorine and fluorine, with chlorine and fluorine being more preferred. Preferred R-groups are those wherein there is one substituent in the 3-or 4-position, e.g., 4-Cl-phenyl or 3-F-phenyl. If there are two substituents, then the 3,5-substituted compounds are preferred. The preferred meaning of R 5 is hydrogen. Most preferred are compounds of formula II.
PREPARATION OF FINAL PRODUCTS
Compounds of the formula I can be prepared by standard methods known in the art. Typical methods appropriate for the preparation of the compounds of the formula I are illustrated below. In the reaction schemes below only one R 1 or one R 7 group is shown; however, compounds having the other two groups (i.e., the other R 1 and R 7 ) can also be made by the reactions described below. The particular process chosen should not cause significant decomposition elsewhere in the molecule; for example, removal of a protecting group by hydrogenolysis should not cause the loss of an essential phenylmethyl group.
Basically well known processes such as those described in WO 95/14007 referred to above can, with some modifications, depending on the nature of the group X, be used. The general aspect of the processes for making the final compounds can be illustrated by the following reaction scheme: ##STR5##
R 1 , R 7 , R 15 , R, Y, Z, (a), n, m, p and q are as defined for formula I, and Z 1 and Z 2 are reactive groups selected in such a manner that they provide the group X in the final compound. Obviously certain groups may have to be protected during the reaction(s). This applies in particular to the NH-group in the imidazole ring. Standard procedures for protection and de-protection may be used.
Starting compounds of formulas A and B are either known or may be prepared according to well known procedures. Reactions 1, 2 and 3 below illustrate the preparation of such compounds.
Reaction 1 (n=1)
For n=1, a metal derivative of an N-protected imidazole (wherein M is e.g., MgBr or MgI, and Pg represents a suitable protecting group, such as, triphenylmethyl) can be reacted with a Z 3 -substituted-benzaldehyde of the formula IX, and the resulting substituted benzyl alcohol can be reduced, for example, as indicated in the following scheme: ##STR6## Reaction 2 (n=1)
A further method is illustrated in the reaction scheme below. A solution of sodium bis(trimethylsilyl)amide in THF cooled to 0° C. is treated with triethylphosphonoacetate. Terephthalaldehyde mono-(diethyl acetal) dissolved in THF is added. The reaction mixture is stirred at 30-40° C. for 3-4 h and concentrated. The residue is washed with H 2 O and brine, dried and concentrated to give the crude desired compound which is then purified. Tr represents trityl. ##STR7## Reaction 3 (n=2)
For n=2, the following scheme can be used: ##STR8##
In the above reaction schemes, wherein the substituents R 1 and R 7 were not included in the formulas, it will be apparent to those skilled in the art that starting compounds wherein such substituents are present could also be used in the reactions described.
Z 3 represents a group --(CH 2 ) m --CR 15 ═CH--(CH 2 ) p --Z 1 or a group which may be converted into such a group. Ph represents a phenyl group. Other procedures for making compounds of formula A may be found in WO 95/14007. In the following reaction schemes some procedures for preparing the appropriate Z 3 group are shown. Additional examples are found in WO 95/14007.
The final compounds of this invention are then prepared by reacting a compound A with a compound B followed by the removal of any protecting groups. Such reactions are illustrated in the reaction schemes below. (R 6 represents the group --(Y) q --R).
In the reaction schemes below, J represents (Z) n .
Reaction 4--Carbamates
Step 1 ##STR9##
In Step 1, the ester 1 is dissolved in a suitable solvent such as THF, ether, dioxane, toluene or methylene chloride, preferably THF, and is treated with a reducing agent such as lithium aluminum hydride or diisobutylaluminum hydride, preferably diisobutylaluminum hydride, at a temperature of from -20° C. to about 50° C., preferably 0° C., to give the alcohol 2. R 9 is lower alkyl
Step 2 ##STR10##
In Step 2, the alcohol 2 is dissolved in a suitable solvent such as THF, ether, dioxane, toluene or methylene chloride, preferably THF, and is treated with an isocyanate R 6 NCO in the presence of a base such as triethylamine or the like at a temperature of from -20° C. to 50° C. to yield the carbamate 4.
Step 3 ##STR11##
In Step 3, a solution of the carbamate 5 in a suitable alcoholic solvent such as methanol or ethanol, preferably methanol, is treated with a dilute solution of a mineral acid such as HCl in methanol at a temperature of from 20° C. to 100° C., preferably 60° C., to give the product 6.
Reaction 5--Esters
Step 1 ##STR12##
In Step 1 the alcohol 3 is reacted with an acid chloride, R 6 C(O)Cl in an inert solvent such as ether, THF, dioxane, or methylene chloride, preferably methylene chloride, in the presence of a tertiary amine base such as triethylamine at a temperature of from 0° C. to 50° C., preferably 0° C., to give the product 7.
Step 2 ##STR13##
In an analogous manner to that described above, compound 7 is transformed to compound 8.
Reaction 6--Ethers ##STR14##
A solution of alcohol 3 in a suitable solvent such as THF or dioxane, preferably THF is added to a suspension of a hydride base such as NaH or KH, preferably NaH, in THF at a temperature of from 0° C. to 50° C., preferably 0° C. The reaction is allowed to warm to room temperature for a suitable time to complete alkoxide formation. A suitable alkylating agent, R 6 L is added and the reaction stirred for a suitable period of time to complete the reaction. Suitable leaving groups L include Cl, Br, I, and activated forms of OH such as OSO 2 CF 3 . Other strong bases can include lithium diisopropylamide and lithium or sodium bistrimethylsilylamide. Deprotection as described above provides the desired compound.
Reaction 7--Amines ##STR15##
A solution of the acetate 11 and an amine R 5 R 6 NH in a suitable solvent such as THF, dioxane, toluene, DMF or the like, preferably THF, is treated with a suitable palladium catalyst such as tetrakis(triphenylphosphine)-palladium at a temperature of from 0° C. to about 100° C., preferably 65° C. to give the amine 12. Deprotection as above gives the amine.
Reaction 8--Amines
Step 1 ##STR16##
The acetate 11 is treated in an analogous manner to that above substituting trimethylsilylazide for the amine R 5 R 6 NH to give an allylic azide. Alternatively, instead of trimethylsilylazide, 11 can be treated with NaN 3 in a THF/water mixture in the presence of a palladium catalyst to give the azide. In part 2, the azide is reduced to the amine 14 by dissolution in a suitable organic solvent such as methanol or ethanol, preferably ethanol, adding a hydrogenation catalyst such as Pd/C, PtO 2 , or Raney Ni, preferably Pd/C, and hydrogenating under an atmosphere of hydrogen (16-60 psi, preferably 60 psi) to give 14. Other reduction methods that can serve equally well include treatment of the azide with NaBH 4 , LiBH 4 , LiAIH 4 , or the like, or with a tertiary phosphine in a water/THF mixed solvent system.
Step 2 ##STR17##
In Step 2, the amine 14 is dissolved in a polar solvent such as methanol, ethanol, or trifluoroethanol and treated with an aldehyde R 5 CHO or ketone (R 5 ) 2 CO in the presence of powdered molecular sieves at a temperature of from 0° C. to 80° C., preferably 22° C. for a time sufficient to ensure imine formation. A reducing agent such as NaBH 3 CN or Na(AcO) 3 BH, preferably Na(AcO) 3 BH, is added and the reaction stirred until complete. Deprotection of the amine 15 gives the product 16.
Reaction 9--Amides ##STR18##
The reactions can be run in a manner analogous to that described for preparing the ester above to give the product 19. Alternatively, the amine 17 can be coupled with a carboxylic acid R 6 CO 2 H by treating a solution of 17 in an inert solvent such as methylene chloride with EDCI, HOBT, NMM, and the acid at a temperature of from 0° C. to 80° C. preferably 22° C.
Reaction 10--Ureas ##STR19##
These reactions are run in a manner analogous to Step 2 and 3 of the reactions for preparing the carbamates above.
Reaction 11--Sulfides ##STR20##
The acetate 22 is reacted with a thiol R 6 SH in a manner similar to that described above for the synthesis of an amine from the acetate to give the sulfide 23 which is deprotected to give the product 24.
Reaction 12--Sulfones ##STR21##
The sulfide 23 is reacted with a suitable oxidizing agent such as m-CPBA or oxone, preferably oxone, in a suitable organic solvent at a temperature of from 0° C. to 80° C., preferably 22° C., to give the sulfone 25. Compound 25 is deprotected to give the product
Reaction 13-- --S(O)NR 5 -- ##STR22##
The aldehyde 27 is treated in a similar manner to that described in Gazz. Chim. Ital. 1991, 121, 471 to afford the vinyl sulphenamide 28. Compound 28 is then deprotected to give the target 29.
Reaction 14-- --SO 2 -- ##STR23##
The aldehyde 27 is treated in a similar manner to that described in Ind. J. Chem., Sec B 1982, 21B, 208 to afford the vinyl sulphone 30. Compound 30 is then deprotected to give the target 31.
Reaction 15-- --SO 2 NR 5 -- ##STR24##
The aldehyde 27 is treated in a similar manner to that described in Synthesis 1975, 321 to afford the vinyl sulphonamide 32. Compound 32 is then deprotected to give the target 33.
Reaction 16-- --C(NH)NR 5 -- ##STR25##
A solution of diethyl- or dimethylcyanomethyl phosphonate in a suitable organic solvent such as THF, ether, or dioxane, preferably THF, is treated with a strong base such as lithium diisopropylamide, or lithium, sodium or potassium bis(trimethylsilyl)amide at a temperature of from -25° C. to about 50° C., preferably 0° C. After 1 hr, the phosphonate carbanion is treated with a solution of the aldehyde 27 in the same solvent. The reaction is stirred at a temperature suitable to complete the reaction and give 34.
Compound 34 is then reacted with the reagent formed by combining equimolar amounts of trimethylaluminum and a suitable amine R 5 R 6 NH in an inert organic solvent such as toluene or xylene, preferably toluene, at a temperature of from 20° C. to 130° C. preferably 90° C. to give compound 35.
Deprotection of compound 35 gives the product 36.
Reaction 17-- --CONR 5 --
In this reaction scheme K represents (Z) n-1 . ##STR26## wherein R 18 is lower alkyl, and R 17 is lower alkyl or the two R 17 groups together with the oxygen atoms to which they are bound form a 5 or 6 membered ring.
Triethylphosphonoacetate is treated with a strong base such as LDA or lithium, sodium or potassium bis(trimethylsilyl)amide in an ethereal solvent such as THF, ether, or dioxane, preferably THF, at a temperature from -20° C. to 50° C., preferably 0° C. The phosphonate stabilized carbanion is then treated with the carbonyl compound 37 and the mixture stirred at room temperature until the reaction is complete. Other suitable bases include NaH or KH in a polar aprotic solvent such as DMSO or DMF. The product 38 is then deprotected as described above to give the aldehyde 39.
The imidazole compound obtained by the reaction ##STR27## is then reacted with the aldehyde 39 to give 40 which is reduced to compound 41. Deprotection provides the compound 42 which is then reacted with the amine NHR 5 R 6 to give the final compound 43.
Compounds useful in this invention are exemplified by the following examples, which should not be construed to limit the scope of the disclosure.
EXAMPLE 1 ##STR28## Step 1
A solution of 1 M sodium bis(trimethylsilyl)amide in THF (110 ml, 110 mmol) cooled to 0° C. was treated with triethylphosphonoacetate (23.5 ml, 118 mmol). After 20 min. the reaction mixture was warmed to RT. and terephthalaldehyde mono-(diethyl acetal) (19.3 ml, 97.0 mmol) dissolved in THF (250 ml) was added over 25 min. The reaction mixture was stirred at 35° C. for 3.5 h and concentrated. The residue was suspended in EtOAc (250 ml), washed with H 2 O (100 ml) and brine (100 ml), dried with MgSO 4 and concentrated to give 27 g of crude intermediate.
The crude intermediate (27 g) was dissolved in acetone (350 ml) and H 2 O (4.5 ml), treated with Amberlyst-15 resin (3.1 g) for 2.5 h, filtered and concentrated to give the aldehyde intermediate.
To a cooled (0° C.) solution of 4-iodo-1-trityl imidazole (41.3 g, 96.9 mmol) in CH 2 Cl 2 (500 ml) was added 3M EtMgBr (35 ml, 105 mmol) over 15 min. After 30 min. at 0° C. the reaction mixture was warmed to RT. and a solution of the aldehyde intermediate in CH 2 Cl 2 (50 ml) was added. After 2 h, the reaction mixture was added to 1 L of half sat. aqueous NH 4 Cl. The organic layer was partitioned off and the aqueous layer was extracted with CH 2 Cl 2 (3×200 ml). The combined organic layers were washed with brine (250 ml), dried with MgSO 4 and concentrated. The product was purified by silica gel chromatography eluting with 1:1 CH 2 Cl 2 -EtOAc to give 30.2 g of product (59 mmol, 61% overall yield): 1 H-NMR (CDCl 3 ) δ 1.34 (t, J=7.1 Hz, 3H), 4.26 (q, J=7.1 Hz, 2H), 5.79 (s, 1H), 6.40 (d, J=16.0 Hz, 1H), 6.59 (s, 1H), 7.1-7.5 (m, 20H), 7.65 (d, J=16.0 Hz, 1H).
Step 2
To a solution of the product from Step 1 (10.2 g, 19.9 mmol), CH 2 Cl 2 (115 ml), acetone (115 ml) and Nal (11.9 g, 79.3 mmol) was added dichlorodimethylsilane (19.4 ml, 159 mmol). After 15 min. the reaction mixture was added to CH 2 Cl 2 (600 ml) and washed with 10% aqueous sodium thiosulfate (5×400 ml), H 2 O (2×400 ml) and brine (400 ml), dried with MgSO 4 and concentrated. The product was purified by silica gel chromatography eluting with 2:1 followed by 1:1 CH 2 Cl 2 -EtOAc to give 7.2 g of product (14 mmol, 72% yield). 1 H-NMR (CDCl 3 ) δ 1.33 (t, J=7.0 Hz, 3H), 3.90 (s, 2H), 4.26 (q, J=7.0, 2H), 6.39 (d, J=16.0 Hz,1H), 6.58 (s, 1H), 7.1-7.5 (m, 20H), 7.65 (d, J=16.0 Hz, 1H).
Step 3
To a cooled (0° C.) solution of 4-chlorobenzylamine (61 ml, 0.50 mmol) in toluene (2.0 ml) was added 2M trimethyl aluminum in toluene (1.0 ml, 2.0 mmol) in toluene (10 ml) and stirred at RT. for 45 min. To the reaction mixture was added a solution of the product from step 2 (0.25 g, 0.50 mmol) in toluene (5.0 ml). After heating at 65° C. for 3.5 h, the reaction mixture was cooled, carefully quenched with sat. Na 2 SO 4 (aq.), concentrated and purified by silica gel chromatography eluting with 5% NH 3 sat. MeOH in CH 2 Cl 2 to give 0.14 g of the amide intermediate (0.23 mmol, 46% yield).
A solution of the amide intermediate (0.14 g, 0.23 mmol) in EtOH (5.0 ml) was treated with 3M HCl (5.0 ml) at 65° C. for 3 h and concentrated. Purification by silica gel chromatography eluting with 5% NH 3 sat. MeOH in CH 2 Cl 2 followed by acidification with 3M HCl and concentration gave 42 mg of the titled product (0.11 mmol, 48% yield). HRMS (M+H + ): m/e calc'd [C 20 H 19 N 3 OCl] + : 352.1217, found 352.1218.
EXAMPLE 2
Step 1 ##STR29##
The acid was suspended in SOCl 2 (20 ml) and stirred for 20 hours at room temperature. The excess SOCl 2 was removed under reduced pressure and the residue dried by azeotropic removal of toluene. The resulting yellow solid was used directly in the next step without purification.
Step 2 ##STR30##
4-Chlorobenzyl alcohol (0.71 g, 5 mmol) and triethylamine (1.01 g, 10 mmol) were added to a suspension of the acid chloride from Step 1 in dry methylene chloride (15 ml) at 0° C. The reaction mixture was warmed to room temperature and stirred for 24 hours. Additional methylene chloride (50 ml) was added and the organic layer was washed with saturated aqueous NaHCO 3 . The organic layer was separated and dried (MgSO 4 ). Concentration gave an amber oil that was purified on a flash column (97:3 CH 2 Cl 2 :MeOH/NH 3 ). A white solid was obtained (0.36 g, 46% from nitrile 4). This material was dissolved in methylene chloride (10 ml) and 1N HCl in ether (5 ml) was added. The solvent was evaporated under a stream of dry argon to give the compound as a white solid.
EXAMPLE 3
Step 1 ##STR31##
Treat a solution of 1(4.84 gr., 10 mmol) in dry THF (50 ml) at 0° C. and under a nitrogen atmosphere with a solution of LAH in THF (12.5 ml of a 1 M solution, 12.5 mmol). Stir the reaction until TLC indicates the reaction is complete. Dilute the reaction with ether (50 ml) and quench by the addition of saturated aqueous Na 2 SO 4 . After drying with solid Na 2 SO 4 , the mixture can be filtered, concentrated, and purified via flash column chromatography to give the product 2.
Step 2 ##STR32##
Stir a solution of the alcohol 2 (2.28 gm., 5 mmol) and the isocyanate (0.92 gm., 6 mmol) in dry THF (25 ml) under a nitrogen atmosphere until TLC indicates that the reaction is complete. Remove the THF under reduced pressure, and purify the residue via flash column chromatography to give the product 3.
Step 3 ##STR33##
In a manner similar to that described in Example 1, compound 3 (1 gm., 1.6 mmol) may be converted into the product 4.
EXAMPLE 4
Step 1 ##STR34##
Treat a solution of the alcohol 4 (2.28 gm., 5 mmol) and DMAP (61 mg, 0.5 mmol) in dry methylene chloride (20 ml) at 0° C. under a nitrogen atmosphere with acetic anhydride (0.61 gm, 6 mmol). Stir the reaction until TLC indicates that it is complete. Dilute the reaction with additional methylene chloride (50 ml) and wash with saturated aqueous NaHCO 3 , brine and dry (MgSO 4 ). Filtration and concentration under reduced pressure gives a residue that can be purified via flash column chromatography to yield the product.
Step 2 ##STR35##
Stir a mixture of dipalladium tris(dibenzylidine acetone) (92 mg, 0.1 mmol), triphenylphosphine (210 mg, 0.8 mmol), trimethylsilyl azide (690 mg, 6 mmol) and compound 5 (1.92 gm, 4 mmol) in dry THF (20 ml) under nitrogen at 50° C. until TLC indicates the reaction is complete. Concentration under reduced pressure gives a residue that can be purified via flash column chromatography to yield the product 6.
Step 3 ##STR36##
Treat a solution of the azide 6 (1.44 gm, 3 mmol) in THF (10 ml) with triphenylphosphine (0.77 gm, 3 mmol) and water (81 mg, 4.5 mmol) and stir until TLC indicates the reaction is complete. The solvent can be removed under reduced pressure and the residue can be purified via flash column chromatography to yield the product 7.
Steps 4 and 5 ##STR37##
In a manner similar to that described in Example 2 Steps 2 and 3, compound 7 (0.46 gm, 1 mmol) may be converted to the product 8.
EXAMPLE 5
Step 1 ##STR38##
Heat compound 9 (2.14 gm, 5 mmol), ammonium acetate (100 mg), and the sulfonylacetic acid reagent (synthesized according to the procedure described in Synthesis, 1975, 321; 1.05 gm, 4.2 mmol) at reflux until TLC indicates the reaction is complete. Dilute with methylene chloride (100 ml) and wash with dilute HCl, aqueous NaHCO 3 , water, brine and dried (MgSO 4 ). After filtration and concentration under reduced pressure, the residue can be purified via flash column chromatography to yield the product 10.
Step 2 ##STR39##
In a manner similar to that described in Example 2 Step 3, compound 10 (0.62 gm, 1 mmol) may be converted to the product 11.
Following the procedures outlined above the compounds ("Com") of formula IA: ##STR40## may be prepared wherein the substituents are defined in the table below. In the table R 1 represents the substituent on the imidazole ring. R 1 for the (Z) n group is H.
__________________________________________________________________________Com. No. n m p q Y X R R.sup.1__________________________________________________________________________1 1 0 0 0 -- CONH 4-chlorophenyl H 2 1 0 0 1 CH.sub.2 CONH 4-chlorophenyl H 3 1 0 0 1 CH.sub.2 CH.sub.2 CONH 4-chlorophenyl H 4 1 0 0 0 -- CON(CH.sub.3) 4-chlorophenyl H 5 1 0 0 1 CH.sub.2 CH.sub.2 CON(CH.sub.3) 4-chlorophenyl H 6 1 0 0 0 -- CONH phenyl H 7 1 0 0 0 -- CONH cyclohexyl H 8 1 0 0 1 --CH.sub.2 CH.sub.2 -- CONH 3-chlorophenyl H 9 1 0 0 1 CH(CH.sub.3)CH.sub.2 CONH 4-chlorophenyl H 10 1 0 0 1 CH.sub.2 CH(CH.sub.3) CONH phenyl H 11 1 0 0 1 CH.sub.2 CH.sub.2 CONH 4-methoxy- H phenyl - 12 1 0 0 1 CH.sub.2 CH.sub.2 CONH H TR41## - 13 1 0 0 0 -- CONH 4-chlorophenyl 1-CH.sub.3 14 1 0 0 0 -- CONH 3-chlorophenyl 1-CH.sub.3 - 15 1 0 0 1 CH.sub.2 CH.sub.2 CONH H TR42## - 16 1 0 0 1 CH.sub.2 CH.sub.2 CONH 3-fluorophenyl H 17 1 0 0 1 CH.sub.2 CH.sub.2 CONH 3-pyridyl H 18 1 0 0 1 CH.sub.2 CH.sub.2 CONH 2-fluorophenyl H 19 1 0 0 1 CH.sub.2 CH.sub.2 CONH 2-chlorophenyl H - 20 1 0 0 1 CH.sub.2 CH.sub.2 CH.sub.2 CONH H TR43## - 21 1 0 0 1 CH.sub.2 CONH H TR44## - 22 1 0 0 1 CH.sub.2 CH.sub.2 CONH 4-methyl- H phenyl - 23 1 0 0 1 CONH phenyl H - 24 1 0 0 0 -- CONH H TR46## - 25 1 0 0 0 -- CO 4-chlorophenyl H - 26 1 0 0 1 CH.sub.2 CONH #STR47## - 27 1 0 0 1 CH.sub.2 CH.sub.2 CONH H TR48## - 28 1 0 0 1 CH.sub.2 CH.sub.2 CONH 2m4-dichloro- H phenyl 29 1 0 0 1 CH.sub.2 CH.sub.2 CONH phenyl H 30 1 0 0 0 -- CONH 3,5-dichloro- H phenyl 31 1 0 0 0 -- CONH 3-chlorophenyl H 32 1 0 0 0 -- CONH 3-cyanophenyl H 33 1 0 0 0 -- CONH 3-methoxy- H phenyl 34 1 0 0 0 -- CONH 3,5-dimethyl- H phenyl 35 1 0 0 0 -- CONH 3-fluorophenyl H 36 1 0 0 0 -- CONH 4-fluorophenyl H 37 1 0 0 0 -- CONH 3-trifluoro- H methoxy- phenyl 38 1 0 0 0 -- CONH 4-trifluoro- H methoxy- phenyl 39 1 0 1 0 -- NHCONH 3,5-dimethyl- H phenyl 40 1 0 1 0 -- NHCONH 3-fluorophenyl H 41 1 0 1 0 -- NHCONH 4-fluorophenyl H 42 1 0 1 0 -- NHCONH 3-trifluoro- H methoxy- phenyl 43 1 1 1 0 -- NHCONH 4-trifluoro- H methoxy- phenyl 44 1 1 1 0 -- NHCONH 3-methoxy- H phenyl 45 1 1 1 0 -- NHCONH 3,5-dimethyl- H phenyl 46 1 1 1 0 -- NHCONH 3-fluorophenyl H 47 1 1 1 0 -- NHCONH 4-fluorophenyl H 48 1 1 1 0 -- NHCONH 3-trifluoro- H methoxy- phenyl 49 1 0 1 0 -- NHCONH 4-trifluoro- H methoxy- phenyl - 50 2 0 1 1 CH.sub.2 OCONH H TR49## - 51 2 1 1 1 CH.sub.2 CH.sub.2 OCONH H TR50## - 52 1 0 1 1 CH.sub.2 CH.sub.2 OCONH 2,4-dichloro- H phenyl 53 1 0 1 1 CH.sub.2 CH.sub.2 OCONH phenyl H 54 1 0 0 0 -- COO 3-methoxy- H phenyl 56 1 0 0 0 -- N(CH.sub.3) 3,5-dimethyl- H phenyl 57 1 0 0 0 -- NH 3-fluorophenyl H 58 1 0 0 0 -- SO.sub.2 NH 4-fluorophenyl H 59 1 0 0 0 -- C(NH)NH 3-trifluoro- H methoxy- phenyl 60 1 0 0 0 -- S 4-trifluoro- H methoxy- phenyl 61 1 0 0 0 -- CONH 4-chlorophenyl H 62 1 0 0 0 -- C(NH)NH 4-chlorophenyl H__________________________________________________________________________
Also, following the above procedures compound 63: ##STR51## was prepared.
EXAMPLE 66 ##STR52##
A solution of terephthalaldehyde mono-(diethyl acetal) (5.0 ml, 25 mmol) in THF (100 ml) was treated with 1.4 M MeMgBr (21.5 ml, 30 mmol). After 30 min, the reaction mixture was added to water (200 ml) and extracted with EtOAc (200 ml). The organic layer was washed with brine (100 ml), dried with Na 2 SO 4 and concentrated to give the crude alcohol intermediate as a colorless oil.
To a 0° C. solution of the crude alcohol intermediate dissolved in EtOAc (150 ml) was added a solution of NaBr (2.60 g, 25.3 mmol) in sat. aq. NaHCO 3 (150 ml) and TEMPO (39 mg, 0.25 mmol). While rapidly stirring the reaction mixture, 0.7 M aq. NaOCl (36 ml, 25 mmol) was added over 20 min then sat. Na 2 S 2 O 3 (50 ml). After warming to RT, the reaction mixture was partitioned and the aqueous layer was extracted with EtOAc (3×50 ml). The combined organic layers were washed with brine (100 ml), dried with Na 2 SO 4 and concentrated to give 4.86 g of the ketone product (21.9 mmol, 87% yield for two steps) as a yellow oil.
Following a procedure similar to that of Example 1, the ketone was converted to the final product. The (E) isomer: ##STR53## and the (Z) isomer: ##STR54## of the final product were obtained.
The data for these two isomers were:
(E)-N-(4-chlorophenyl)-3-[4-[(1H-imidazol-4-yl)methyl]-phenyl]-3-methyl-2-propenamide: 1 H-NMR (CD 3 OD)δ 2.64 (s, 3H), 4.03 (s, 2H), 6.43 (s, 1H), 6.88 (s, 1H), 7.35 (d, J=8 Hz, 2H), 7.37 (d, J=9 Hz, 2H), 7.57 (d, J=8 Hz, 2H), 7.68 (s, 1H), 7.70 (d, J=9 Hz, 2H); HRMS (M+H + ): m/e calc'd [C 20 H 19 N 3 OCl] + : 352.1217, found 352.1214.
(Z)-N-(4-chlorophenyl)-3-[4-[(1H-imidazol-4-yl)methyl]-phenyl]-3-methyl-2-propenamide: 1 H-NMR (CD 3 OD)δ 2.27 (s, 3H), 3.99 (s, 2H), 6.16 (s, 1H), 6.83 (s, 1H), 7.4 (m, 6H), 7.43 (d, J=8 Hz, 2H), 7.65 (s, 1H); HRMS (M+H + ): m/e calc'd [C 20 H 19 N 3 OCl] + : 352.1217, found 352.1227.
Mass Spectral Data of Compounds:
______________________________________Compound # Calculated Found______________________________________ 1 338.1060 338.1066 2 352.1217 352.1218 3 366.1373 366.1372 4 352.1217 352.1214 5 380.1530 380.1525 6 304.1540 304.1449 7 310.1919 310.1917 8 366.1373 366.1371 9 380.1530 380.1532 10 346.1919 346.1924 11 362.1869 362.1862 12 371.1872 371.1875 15 338.1327 338.1331 16 350.1669 350.1667 17 333.1715 333.1720 18 350.1669 350.1670 19 366.1373 366.1372 21 308.1399 308.1405 22 346.1919 346.1916 23 360.2076 360.2074 24 358.1919 358.1924 26 368.1763 368.1763 28 400.0983 400.099329 FAB = 332 (M + 1)30 372.0670 372.0673 31 338.1060 338.1069 32 329.1402 329.1402 33 334.1556 334.1559 35 322.1356 322.1356 36 322.1356 322.1356 37 388.1273 388.1274 38 388.1273 388.1270 39 332.1763 332.1762______________________________________
Additional mass spectral data are: (1) Compound No. 61-352 (M+1); and (2) Compound No. 62-FAB 337 (M+1).
H 3 Receptor Binding Assay
The source of the H 3 receptors in this experiment was guinea pig brain. The animals weighed 400-600 g. The brain tissue was homogenized using a Polytron in a solution of 50 mM Tris, pH 7.5. The final concentration of tissue in the homogenization buffer was 10% w/v. The homogenates were centrifuged at 1,000×g for 10 min. in order to remove clumps of tissue and debris. The resulting supernatants were then centrifuged at 50,000×g for 20 min. in order to sediment the membranes, which were next washed three times in homogenization buffer (50,000×g for 20 min. each). The membranes were frozen and stored at -70° C. until needed.
All compounds to be tested were dissolved in DMSO and then diluted into the binding buffer (50 mM Tris, pH 7.5) such that the final concentration was 2 μg/ml with 0.1% DMSO. Membranes were then added (400 μg of protein) to the reaction tubes. The reaction was started by the addition of 3 nM [ 3 H]R-α-methylhistamine (8.8 Ci/mmol) or 3 nM [ 3 H]N.sup.α -methylhistamine (80 Ci/mmol) and continued under incubation at 30° C. for 30 min. Bound ligand was separated from unbound ligand by filtration, and the amount of radioactive ligand bound to the membranes was quantitated by liquid scintillation spectrometry. All incubations were performed in duplicate and the standard error was always less than 10%. Compounds that inhibited more than 70% of the specific binding of radioactive ligand to the receptor were serially diluted to determine a K i (nM).
______________________________________ Compound # K.sub.i (nM)______________________________________ 1 2 2 23 3 7 4 45 5 35 6 2 7 26 8 11 9 10 10 19 11 7 12 45 13 270 15 12 16 10 17 190 18 10 19 12 20 580 21 110 22 6 23 37 24 220 25 400 26 200 27 1000 28 36 29 17 30 12 31 4 32 4 33 3 34 2 35 1 36 5 37 8 38 10______________________________________
From these test results and the background knowledge about the compounds described in the references in the section "Background of the Invention", it is to be expected that the compounds of the invention would be useful in treating inflammation, allergy, diseases of the GI-tract, cardiovascular disease, or disturbances of the central nervous system.
Pharmaceutically acceptable inert carriers used for preparing pharmaceutical compositions from the compounds of Formula I and their salts can be either solid or liquid. Solid form preparations include powders, tablets, dispersible granules, capsules, cachets and suppositories. The powders and tablets may comprise from about 5 to about 70 percent active ingredient. Suitable solid carriers are known in the art, e.g. magnesium carbonate, magnesium stearate, talc, sugar, lactose. Tablets, powders, cachets and capsules can be used as solid dosage forms suitable for oral administration.
Liquid form preparations include solutions, suspensions and emulsions, for example water or water-propylene glycol solutions for parenteral injection. Liquid form preparations may also include solutions for intranasal administration.
Also included are solid form preparations which are intended for conversion, shortly before use, into liquid form preparations for either oral or parenteral administration. Such liquid forms include solutions, suspensions and emulsions.
Aerosol preparations suitable for inhalation may include solutions and solids in powder form, which may be in combination with a pharmaceutically acceptable carrier, such as an inert compressed gas.
For preparing suppositories, a low melting wax such as a mixture of fatty acid glycerides or cocoa butter is first melted, and the active ingredient is dispersed homogeneously therein as by stirring. The molten homogeneous mixture is then poured into conveniently sized molds, and allowed to cool and thereby solidify.
Preferably the compound is administered orally.
Preferably, the pharmaceutical preparation is in unit dosage form. In such form, the preparation is subdivided into unit doses containing appropriate quantities of the active component, e.g., an effective amount to achieve the desired purpose. The quantity of active compound in a unit dose of preparation may be varied or adjusted from about 0.1 mg to 1000 mg, more preferably from about 1 mg to 500 mg, according to the particular application.
The actual dosage employed may be varied depending upon the requirements of the patient and the severity of the condition being treated. The determination of the proper dosage for a particular condition is within the skill of the art. Generally, treatment is initiated with smaller dosages which are less than the optimum dose of the compound. Thereafter, the dosage is increased by small amounts until the optimum effect under the circumstances is reached. For convenience, the total daily dosage may be divided and administered in portions during the day it desired.
The amount and frequency of administration of the compounds of the invention and the pharmaceutically acceptable salts thereof will be regulated according to the judgment of the attending clinician considering such factors as age, condition and size of the patient as well as severity of the symptoms being treated. A typical recommended dosage regimen is oral administration of from 1 mg to 2000 mg/day, preferably 10 to 1000 mg/day, in one to four divided doses to achieve relief of the symptoms. The compounds are non-toxic when administered at therapeutic doses.
The following are examples of pharmaceutical dosage forms which contain a compound of the invention. As used therein, the term "active compound" is used to designate one of the compounds of the formula I or salt thereof, especially compounds 6 and 29 herein (as free base), namely N-[(4-chlorophenyl)methyl]-4-[(1H-imidazol-4-yl)methyl]benzene methanimidamide and N-[(4-chlorophenyl)methyl]-4-[(1H-imidazol-4-yl)methyl]benzene ethanimidamide, or the dihydrochloride thereof, but any other compound of the formula I or salt thereof can be substituted therefor:
Pharmaceutical Dosage Form Examples
EXAMPLE A
Tablets
______________________________________No. Ingredients mg/tablet mg/tablet______________________________________1. Active compound 100 500 2. Lactose USP 122 113 3. Corn Starch, Food Grade, 30 40 as a 10% paste in Purified Water 4. Corn Starch, Food Grade 45 40 5. Magnesium Stearate 3 7 Total 300 700______________________________________
Method of Manufacture
Mix Items No. 1 and 2 in a suitable mixer for 10 to 15 minutes. Granulate the mixture with Item No. 3. Mill the damp granules through a coarse screen (e.g., 1/4", 0.63 cm) if necessary. Dry the damp granules. Screen the dried granules if necessary and mix with Item No. 4 and mix for 10-15 minutes. Add Item No. 5 and mix for 1 to 3 minutes. Compress the mixture to appropriate size and weigh on a suitable tablet machine.
EXAMPLE B
Capsules
______________________________________No. Ingredient mg/capsule mg/capsule______________________________________1. Active compound 100 500 2. Lactose USP 106 123 3. Corn Starch, Food Grade 40 70 4. Magnesium Stearate NF 4 7 Total 250 700______________________________________
Method of Manufacture
Mix Items No. 1, 2 and 3 in a suitable blender for 10 to 15 minutes. Add Item No. 4 and mix for 1 to 3 minutes. Fill the mixture into suitable two-piece hard gelatin capsules on a suitable encapsulating machine.
While a number of embodiments of this invention are described herein, it is apparent that the embodiments can be altered to provide other embodiments that utilize the compositions and processes of this invention. Therefore, it will be appreciated that the scope of this invention includes alternative embodiments and variations which are defined in the foregoing Specification and by the claims appended hereto; and the invention is not to be limited to the specific embodiments that have been presented herein by way of example. | Disclosed are novel phenyl-alkyl-imidazoles of the formula ##STR1## wherein R 1 , R 7 , m, n, p, q, X, Y, Z, R and R 15 are as defined in the specification.
Also disclosed are pharmaceutical compositions comprising the compounds of formula I.
Further disclosed are methods of treating allergy, inflammation, hypotension, glaucoma, sleeping disorders, states of hyper and hypo motility of the gastrointestinal tract, hypo and hyperactivity of the central nervous system, Alzheimer's, schizophrenia, obesity and migraines by administering compounds of formula I.
Also disclosed are methods for treatment of upper airway allergic responses comprising administering a compound, or salt or solvate thereof, of formula I in combination or admixture with a histamine H 1 receptor antagonist. | 2 |
This is a continuation of application Ser. No. 801,343, filed Nov. 25, 1985 and now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to blends of thermoplastic polymer materials which have improved properties. More particularly the present invention relates to blends of a propylene polymer with a butene-rich butene-1-propylene copolymer which may be fabricated into thermoplastic films and laminar structures which are heat shrinkable and which have good clarity and good processibility.
Thermoplastic blends for films are used as packaging material, and in the area of shrink packaging, for objects that are packaged in thermoplastic shrink film. Shrink film is used in many applications, for example, for many types of packaging and wrapping articles such as toys, sporting goods, stationary, greeting cards, hardware, household products, office supplies and forms, phonograph records, industrial parts, computer floppy diskettes, and photo albums, etc. Heat is applied to the film and the film shrinks to conform to the shape of the article packaged therein.
Many thermoplastic films shrink to some extent if they are subjected to elevated temperatures. Use is made of this characteristic by subjecting objects packaged in such films for a short time to elevated temperatures, e.g. exposing them to a blast of heated air, or by immersing in boiling water so that the film shrinks, thereby tightly enclosing the objects packaged therein. Examples are films fabricated from polyolefins or irradiated polyolefins.
Usually for most shrink film applications, a film should exhibit a high shrink energy or contractile force when exposed to elevated temperatures. In addition, the film should not only be heat shrinkable but have good clarity and be easily processed. Clarity is important in the marketing aspect of the packaged goods so that the consumer can ascertain what he or she is purchasing. Additional advantages of shrink packaging made from blends should include: (1) adds luster, enhances product appearance; (2) imparts contemporary image to the product; (3) helps the product sell itself; (4) keeps out dust and moisture so that the product doesn't become shop worn; (5) discourages shoplifters; (6) speeds production; (7) cuts labor and material costs; (8) reduces labeling cost; (9) easy for packaging operators to use; (10) simplifies internal handling; (11) wraps unusual shapes with a contour fit; (12) versatile--serves many packaging needs; and (13) excellent for bundling and multipackaging.
A shrink film should possess the following specific properties:
(1) the shrink force should be between 100 and 400 grams per inch at 100° C. depending on the objects to be encased.
(2) the percent shrinkage should be between 10 and 50% at 121° C. depending on the objects to be encased.
(3) the film should have high clarity or optics.
(4) the modulus should be between 60,000 and 350,000 psi depending upon the objects to be encased.
(5) machinability: the coefficient of friction should be less than 0.5.
(6) tear strength: the tear strength should be as high as possible; typical is 3 to 15 grams mil of film thickness and per inch of width.
(7) elongation: the elongation should be between 50 and 150% depending on the objects to be encased.
Films from the blends may be oriented or unoriented. Oriented films may be obtained by stretching processes in which tensions capable of stretching the film are applied to the film, the directions of which form an angle of about 90° utilizing well known prior art techniques. These film stretching tensions may be applied sequentially, as in the case for the film, after forming, is subjected to stretching in a longitudinal directions and thereafter tension is applied in a transverse direction to stretch the film transversely, or simultaneously, whereby longitudinal and transverse tensions are applied to the film at the same time resulting in a simultaneous longitudinal and transverse stretching of the film. Such processes are well known in the art and includes for example the "double-bubble" method which comprises extrusion of material into a tubular stalk film, cooling of the tubular stalk, reheating and inflating of the tube and simultaneously drawing the inflated tube in a longitudinal direction thereby imparting biaxial orientation to the film. Another common method for the biaxial orientation of the film sheet comprises passing the film sheet through a series of rotating draw rollers which impart longitudinal direction stretch to the film and subsequently transversely drawing the longitudinally stretched film, for example, by passing it through a tenter frame wherein the film is stretched in a transverse direction.
The film may be sealed around the product, formed into a bag, then subjected to heat and shrunk tightly around the product. A variety of equipment is available for shrink packaging from manual as well as automatic systems.
U.S. Pat. No. 3,900,534 discloses a biaxially oriented thermoplastic film structure formed from a blend comprising polypropylene and polybutene homopolymers where the polybutene is present in a small amount of more than 10% but less than 20% by weight.
U.S. Pat. No. 3,634,553 discloses a heat shrinkable oriented thermoplastic film which comprises a blend of polypropylene and an ethylene/butene-1 copolymer.
European Patent Application No. 0,145,014A discloses a blend of a random copolymer of propylene and an alpha olefin with 4 or more carbon atoms (i.e. perhaps butene-1), where the alpha olefin content in the copolymer is 8 to 30 mole% (m%).
Single layer shrink films based on blends of polybutylene with polypropylene are disclosed in Mobil Patents: U.S. Pat. No. 3,634,552 (1972), U.S. Pat. No. 3,634,553 (1972), U.S. Pat. No. 3,849,520 (1974), U.S. Pat. No. 3,900,534 (1975) and blends of polybutylene with ethylene vinyl acetate (EVA) and C 2 -C.sub.α elastomer or polybutylene with low density polyethylene (LDPE) and C 2 -C.sub.α elastomer (where C.sub.α is an α-olefin comonomer) are disclosed in U.S. Pat. No. 4,379,883 (1983). Multilayers may include three layers (propylene-ethylene plus butene-1-ethylene plus ethylene-propylene rubber)/tie layer/linear low density polyethylene (LDPE) by Union Carbide, U.S. Pat. No. 4,196,240 (1980) for frozen poultry and U.S. Pat. No. 4,207,363 (1980) for primal meat cuts. Three layers of propylene-ethylene/(EVA+butene-1-ethylene)/propylene-ethylene, U.S. Pat. No. 4,194,039 (1980) is known. Also, three layers (polypropylene+polybutylene)/EVA/irradiated EVA by Cryovac, U.S. Pat. No. 3,754,063 (1973), U.S. Pat. No. 3,832,274 (1974), and U.S. Pat. No. 3,891,008 (1975) for turkey bags are known.
Heretofore, polyvinyl chloride (PVC) has been used to produce good shrink films. PVC has been shown to be much better in certain applications than other polyolefins such as propylene polymers. This is because the use of polyolefins in shrink wrap results in a moderate to high shrink force which is undesirable in many applications. However, the use of polyolefins allows for the use of high speed automated packaging machinery with ease of control, lower cost, and less deposit from corrosion of equipment, which results in less equipment maintenance than when using PVC. PVC, however, may produce a better looking package because of the low shrink force and better optics. Also, the seal and shrink may take place over a much broader temperature and tear strength may be better.
It has been desired to produce a blend for producing a heat shrinkable thermoplastic film with the film advantages of PVC but which is of low cost, can be used on a high speed automated packaging machine and which does not corrode equipment. It is the butene-rich butene-1 propylene polymer blend of the present invention which results in low shrink force which is adjustable by the blending ratio, low shrink temperature, low stiffness with better optics, and which does not corrode the equipment being used, is of lower cost and can be ussed on high speed automated packaging machines.
SUMMARY OF THE INVENTION
Applicant has surprisingly discovered a butene-rich butene-1 propylene copolymer where the propylene comonomer content of the butene-1-propylene copolymer is from about 5 m% to about 40 m% and thus the butene-1 content of the butene-1-propylene copolymer is from about 60 m% to about 95 m% which may be blended with a propylene polymer (homo- or copolymer) for producing a heat shrinkable oriented thermoplastic film which also has good clarity and good processability. Heretofore, no such butene-rich butene-1-propylene copolymers have been known which produce a heat shrinkable oriented thermoplastic film which has good clarity and good processability as well as not corroding equipment being used, which may be used as on high speed automated packaging machines.
The invention is a blend for producing a heat shrinkable oriented thermoplastic film which has good clarity and good processability, comprising a mixture containing:
from about 10% by weight to about 60% by weight butene-1 propylene copolymer, where the propylene comonomer content of said butene-1 propylene copolymer is from about 5 m% to about 40 m%; and
from about 40% by weight to about 90% by weight propylene homopolymr or copolymer.
DETAILED DESCRIPTION OF THE INVENTION
The polymer and copolymer components of the film composition of the present invention are blended together to form a substantially homogeneous resin mixture. This may be accomplished, for example, by tumbling the mixture in a fiber drum. The tumbled mixture is then melt compounded by an extruder having good mixing screw and pelletized thereafter. The blend is then extruded into a film utilizing a standard extruder and tubular or flat film die and as subsequently oriented utilizing any one of a number of prior art film orientation techniques.
Various gauges of shrink film may be manufactured through utilizing a novel resin composition of the present invention. The gauge may generally vary from about 0.10 mil to about 5 mils and preferably from about 0.5 mil to about 2.0 mils depending to a great extent upon the type of shrink packaging applications for which the film is manufactured.
The following example as set forth to more clearly illustrate the present invention is not intended to limit the scope thereof.
EXAMPLE 1
A butene-1-propylene copolymer, C-2756, which contains 27 mole % (m%) of propylene comonomer was blended at a 15 weight % (w%) level with a Shell polypropylene random copolymer. This particular copolymer had an ethylene comonomer content of 1.0 wt%, however, the ethylene content may vary considerably. Applicant's blend was compared with (1) polypropylene random copolymer and with, (2) a blend of 15% of polybutylene (a butene-1-ethylene copolymer where the ethylene comonomer content was 0.75 wt% with 85% of the propylene random copolymer (1). This blend of butene-1-ethylene copolymer, where the ethylene comonomer content is 0.75 wt% is patented in Mobil U.S. Pat. No. 3,634,553 and is typical of compositions used heretofore. The polymers were blended utilizing a drum tumbler and subsequently fed into the hopper of the standard rotating screw extrusion apparatus which served to further mix and melt the blend, and then melt extruded and pelletized thereafter. The temperature of the melt within the extruder was maintained at about 465° F.
The blend was subsequently extruded in the shape of a tube from a tubular die affixed to the outlet of an extruder, the die being maintained at a temperature of 370° F. The tube was quenched to a temperature of about 60° F. which was substantially below the crystalline melting points of the propylene polymer and the butene-1 propylene copolymer immediately upon emergence from the die. The extruded tube had an external diameter of about 2 inches and a wall thickness of about 20 mils. Upon cooling, the tube was taken up by a set of draw rollers at about 12 ft/min and passed through a preheat oven where it was reheated. The temperature of the preheat oven was maintained at about 1000° F. The heated tube was immediately reinflated with air under pressure which expanded the heated tube by a ratio of about 5:1 in a transverse direction and a substantially similar ratio in the longitudinal direction. The expanded tube was subsequently collapsed by a pair of nip rollers operating at speeds higher than the rotational speeds of the draw rollers. The tube was passed to a set of windup rollers finally. Table 1 illustrates the properties which resulted from this experiment.
TABLE 1______________________________________PROPERTIES OF SHRINK FILMS* I III PP** II PP + 15% Control PP + 15% C2756 PB8240______________________________________Shrink @ 220° F., %MD 4 7 5TD 8 10 10Shrink @ 250° F., %MD 7 12.5 6.5TD 14 20 15.5Orientation ReleaseStress, psiMD 360 250 354TD 573 365 446Contractive StresspsiMD 236 193 215TD 213 138 108Haze, % 1.9-3.6 2.9-3.9 5Tagent Modulus, psiMD 303,700 222,760 247,860TD 335,680 237,140 255,340Break Strength, psiMD 19,384 16,220 18,478TD 17,483 16,593 15,284Elongation, %MD 61 78 53TD 40 88 52Tear Strength, g/milMD 14 11.6 12.5TD 13.7 13.6 11.9______________________________________ *Tubular OPP Film @ 0.75 mil thickness **A Random Copolymer @ 1.0 w % C2.
Table 1 considers a polypropylene control which is a random copolymer at 1.0 wt% ethylene (Control I), a blend of 85% polypropylene and 15% C-2756 which is applicant's invention with propylene comonomer content of the butene-1 propylene copolymer being 27 m% (Applicant II formulation), and a blend of polypropylene and 15% PB8240 which represents the Mobil U.S. Pat. No. 3,634,553 material of a butene-1-ethylene copolymer where the ethylene comonomer content is 0.75 wt% (Mobil III). The shrink forces both expressed by orientation release stress and contractive stress of applicant's film, II were lower than those of the Mobil III film and much lower than those of Control I film. These lower shrink forces are desirable and, thus, make the butene-1-propylene copolymer modified polyolefins (polypropylene) film useful in many shrink packaging application where low shrink force is required.
As may be seen from Table 1, Applicant II formulation resulted in somewhat higher percent shrinkage at 220° F. then the polypropylenne Control I and shrinkage percentage at least comparable to Mobil III. At a temperature of 250° F., the shrinkage percentage for Applicant II was higher than either Control I or Mobil III.
The modulus and break strength values of Applicant II formulation were quite acceptable. The haze or clarity value of Applicant II formulation was better than Mobil III and as good as Control I. The other properties such as tear strength and elongation are very acceptable, as well. | A blend for producing a heat shrinkable oriented thermoplastic film which has good clarity and good processability, comprising a mixture containing:
from about 10% by weight to about 60% by weight butene-1 propylene copolymer, where the propylene comonomer content of said butene-1 propylene copolymer is from about 5 m % to about 40 m %; and
from about 40% by weight to about 90% by weight propylene homopolymer or copolymer. | 2 |
RELATED APPLICATIONS
[0001] This application claims the benefit of co-pending provisional patent application Ser. No. 61/546,741 filed 13 Oct. 2011.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a sterile covering or barrier protective liquid, gel, material or film and, more particularly to a method of using such a material to create a sterile covering for fingers, hands, arms or other selected skin surface to act as glove substitute.
[0003] During surgery and other medical procedures sterility is essential to prevent contamination and the spread of diseases, bacteria and viruses. Likewise, it is also essential that hand coverings do not limit the surgeon's or medical personnel's feel and touch, e.g. tactile sensation, when performing a medical procedure or examination. In addition, areas like the food industry, salon services, dentistry and a wide variety of other manufacturing and specialty services require protection for themselves and their patients or clients.
[0004] Most commonly, surgical gloves, e.g. latex gloves and non latex polymers, are standard and used during surgery and other procedures. However, the use of surgical gloves may be a cumbersome process when putting on and removing the gloves, creates a great deal of solid waste and may be overkill for certain smaller procedures. They also create a tactile barrier to the sensitivity or the surgeon or person wearing the gloves. While there have been improvements in the strength and thinness of these gloves, they nonetheless tend to be thicker than desired, adding to diminished tactile feeling of the surgeon or medical personnel. There is also increasing medical evidence to show that most patient infections originate from the patient's own skin verses the surgeon's skin. Therefore protection is needed for both the operator and the patient or client.
[0005] Artificial skins have been developed that are used to treat sores and wounds on a patient. Such artificial skins may be sprayed onto the skin or applied topically to particular areas of the skin. However, such artificial skins are not well adapted for surgical uses, as they do not necessarily hold up and are not durable enough to a function in a surgical environment. Further, they do not provide for an adequate barrier of protection, and in addition may not prevent bacteria from growing on the surface as a biofilm.
SUMMARY OF THE INVENTION
[0006] The present invention provides a surgical finger, hand, or arm barrier covering and a method and system of applying the covering. The hand covering provides a durable barrier between medical personnel and a patient during a surgical procedure or examination and also with other nonmedical uses as described above. The hand covering is resistant to dissolution when in contact with bodily fluids or water so that it will retain its protective barrier during the particular medical procedures or examinations, would bind any residual bacteria into the follicles or skin, and create a sterile surface over the fingers or hands circumferentially creating a sterile barrier. In addition, and as a completely different application, the material may also be used as a skin prep application or sealant after the skin prep and applied directly over the skin were an incision is to be made or to cover areas such as the nipple to prevent any bacteria coming from out of the ducts and onto the skin surface or into the wound.
[0007] The present further invention contemplates a method of providing the fingers, hands, or arms with a covering for use during a surgical procedure, and a method of providing a finger covering or a sterile covering for the fingertips only. The process includes dipping the user or medical personnel's fingers or hands in a solution, or suspension of material, removing the hands, and allowing the solution to dry, thereby forming the surgical hand covering. Once the medical procedure is finished, the fingers or hands may be washed in a solution or solvent that will remove the surgical hand covering, if needed. As an alternative, the solution or suspension may be applied to the hands and rubbed in evenly to provide uniform coverage.
[0008] The present invention further contemplates a finger dip apparatus for retention of the solution or suspension, and into which the fingers may be dipped for application. A larger apparatus may also be used to accommodate the entire hand, entire arm, or other larger body area for uniform application of the suspension.
[0009] Alternatively, a sprayer system may be utilized to spray and or dispense the material. After application of the suspension by the sprayer, the covering would be allowed to air dry or may be placed into a air blower or dryer to be dried more quickly.
[0010] In another embodiment, the coating is applied as an extremely thin film to the fingers, hands or arms and peeled off for removal, or removed with a solvent.
[0011] The specific material to be used as a coating may be a single agent such as a silicone or other plastic polymer or a may be combination of materials including antiseptics such as those marketed under the names CHLORAPREP®, HIBICLENS®, BETADINE®. Other alcohols and antibiotics that may further suppress bacteria may be used in combination with other materials such as flexible Collodion, ether free Collodion, cyanoacrylates such as those used in SUPER GLUE®, and DERMABOND® materials. Any of these combinations may also be applied as a thin film or plastic polymer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A depicts the process of applying prior art gloves for use in a medical procedure.
[0013] FIG. 1B depicts the gloves of FIG. 1A being removed after use in medical procedure.
[0014] FIG. 2 demonstrates a first step for applying a surgical finger or hand coating according to the present invention.
[0015] FIG. 3 provides a subsequent step for applying a surgical fingers or hand coating according to the present invention, with the hands being submersed into a solution containing the surgical hand covering material.
[0016] FIG. 4 provides a further step for applying a surgical finger or hand coating according to the present invention, with the hand being removed from the solution and allowed to dry.
[0017] FIG. 5 provides an alternate step for the present solution wherein the hands are rubbed together after being removed from the hand covering solution.
[0018] FIG. 6 depicts a user, such as a surgeon, performing a medical procedure while using the surgical hand coating of the present invention.
[0019] FIG. 7 depicts a surgeon removing the surgical finger or hand coating after surgery.
[0020] FIG. 8 demonstrates a user, such as a surgeon, removing any remaining surgical hand coating by washing the hands in a rinse solution.
[0021] FIG. 9 depicts an alternate first step in the process of the present invention, wherein only the fingers are immersed in the solution containing the surgical hand covering material.
[0022] FIG. 10 depicts the fingers of FIG. 9 being removed from the solution and allowed to dry.
[0023] FIG. 11 demonstrates the use of a syringe after application of the hand solution as shown in FIG. 10 .
[0024] FIG. 12 depicts an alternative first step for applying the material as a spray that is sterilely sprayed on to the user's selected skin surface and allowed to dry or rubbed into the hands or arms.
[0025] FIG. 13 depicts an alternative first step for applying the material, and showing a hoop device inserted into a vessel containing the material.
[0026] FIG. 14 depicts a subsequent step for the method depicted in FIG. 13 , in which the hoop device retains a film of material and the user inserts a selected skin surface, seen as a hand in this view, into the film.
[0027] FIG. 15 depicts another alternative first step for applying the material, and showing an applicator device transferring the material to a selected skin surface.
[0028] FIG. 16 depicts another alternative first step for applying the material, and showing a thin film of the material draped over a selected skin surface.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention which is defined by the claims.
[0030] FIGS. 1A and 1B demonstrate prior art gloves 10 for use in surgical procedures. In FIG. 1A , the gloves 10 are being applied prior to a surgical or medical procedure. The surgeon or other medical personnel will pull the gloves 10 over their hands 11 and adjust them so that they fit properly on the user's hands 11 . The gloves 10 are normally made from a thin silicone, latex or rubber material, e.g. latex, that allow the gloves 10 to be flexible enough so that the user can adjust them for proper fit. Because the gloves 10 are mass produced, the gloves 10 may not adequately fit the user's hands, either being too tight and not properly conforming to the specific user's hands, or they may be too loose, which can result in the gloves 10 being a hindrance during a surgical procedure. If the gloves 10 are too tight, the gloves 10 may also rip when being put on, thereby causing the person to have to remove the gloves, throw them away, and put on a new set of gloves. In addition the glove thickness decreases the tactile sensation or the wearer and also creates and adds to the great medical waste burden.
[0031] FIG. 1B demonstrates the gloves 10 being removed from the user's hands 11 . Removal may be a tedious process, particularly if the gloves 10 tightly fit the user's hands. This is also true because the material of the gloves 10 must also be sufficiently strong to resist tearing and rips that may occur during use.
[0032] As previously noted, the materials used for these gloves 10 are rubber materials such as latex, or other materials with similar properties. Though the gloves 10 are designed to be thin, they must be sufficiently strong, e.g. thick, so that they will not fail during use, often diminishing or lessening the tactile feel of the user.
[0033] The present invention provides an alternative to gloves 10 . The present invention comprises a surgical hand covering that may be applied to the user's fingers in particular and or the hands in general, or may be used to cover any other skin surface. The hand covering will be used in lieu of gloves 10 being put on the user's hands.
[0034] FIG. 2 shows the user's hands 11 prior being covered with the surgical hand covering of the present invention. The user's hands 11 will be washed and sterilized, as is typically done before surgical or medical procedures. A container 13 holding a coating solution 12 is made available to receive the user's hands 11 . The user's hands will be sufficiently dry such that when they are put into the coating solution 12 , the coating solution 12 will sufficiently adhere to the selected skin surface, such as the hands 11 shown in these views.
[0035] As is shown in FIG. 3 , the user dips a selected skin surface, such as hands 11 , into the container 13 so that the hands 11 are covered by the solution 12 . The user will keep them within the solution 12 for a sufficient period of time necessary to coat the hands 11 . The immersion time may be determined by the user. For example, the user may immerse just finger tips into the solution 12 for a quick, simple procedure, e.g. an office check-up, or may immerse the entire hand or arm for use in a more intricate or involved procedure, as for example, a surgical operation. As such, the present invention provides a hand covering that may be tailored particularly to the needs of a specific user and a specific procedure.
[0036] With attention now to FIG. 4 , it may be seen that once the hands 11 are sufficiently coated by the solution 12 , the user will remove the hands 11 from the solution 12 . Any excess coating solution 12 may be removed from the user's hands, if desired, by allowing the excess solution 12 to drip off. The hands 11 are preferably allowed to dry for a predetermined time prior to the performance of the medical or surgical procedure, whereby the surgical hand coating 14 of the present invention is formed. The coating solution 12 is preferably a quick drying solution to insure the hand coating 14 provides the necessary barrier against contamination prior to performing the particular procedure or operation. The step of dipping the hands into the solution 12 may be repeated if additional thickness is required.
[0037] FIG. 5 provides a further step of the method of the present invention. After the user has removed his hands as shown in FIG. 4 , the user may rub his hands together so that the coating solution 12 will be evenly distributed and worked into all portions of the skin, thereby further increasing the hygienic barrier formed by the coating solution 12 .
[0038] As shown in FIG. 6 , the user is able to perform the medical procedure, without the need for gloves 10 . The surgical hand coating 14 provides a sterile barrier that sufficiently prevents the transmission of unwanted materials, e.g. bacteria, in the same manner as for the prior art gloves. Further, the surgical hand coating 14 is thinner than the gloves 10 and directly follows the contours of the individual user's hands, which increases the tactile feel of the user. The result is that the user has better and more precise feel when carrying out a procedure.
[0039] Once the surgical procedure is completed, the surgical hand coating 14 may be peeled away from the user's hands, as is shown in FIG. 7 . Any remaining surgical hand coating 14 may be further washed away in a solvent 16 particular to the composition of the coating solution 12 , as is shown in FIG. 8 . Alternatively, the coating solution 12 may be simply washed away without first peeling away the coating 14 .
[0040] The surgical hand coating 14 of the present invention and the methods of forming the surgical hand coating 14 also allow for hand coatings 14 to be directed towards particular body parts, e.g. the user's fingers. As shown in FIG. 9 , the user may dip only the fingers into the coating solution 12 . The fingers are removed and allowed to dry, as shown in FIG. 10 , in the similar fashion as described previously with respect to the coating for the entire hand.
[0041] The ability to isolate the surgical hand coating 14 to a particular skin surface reduces waste and costs associated with prior art hand coverings 10 . For example, as shown in FIG. 11 , the user may apply the coating only to the fingers, which thereby provides a sufficient barrier for certain routine procedures, such as delivering or injecting a medication with a syringe 18 . Since it is not necessary to sterilize the entire hand for such a procedure, use of the present coating 14 on the fingers only, relieves the user of the unnecessary time and effort required to apply full gloves 10 on the hand. Thus, the procedure is made more efficient than use of the prior art gloves 10 , while also being more cost effective.
[0042] In addition to providing a better fit than prior art gloves 10 and other known hand coverings, the present invention also allows the user to be more responsive to potential problems during a medical procedure. For example, because tactility is improved with the present invention, the user is more able to realize if an instrument pierces through the surgical coating 14 . This minimizes the possibility that contamination is transmitted through open wounds. In the same fashion, the surgical coating solution 12 may include skin color changing agents that react when the surgical coating 14 is pierced, thereby warning the user if the surgical coating 14 is compromised. For example, the surgical coating 14 may change color when pierced by a surgical instrument. Surgical gloves sold under the BIOGEL PI INDICATOR® System name may be seen as an example of such a feature.
[0043] As seen in FIGS. 12-16 , alternative methods of applying the coating solution 12 to a selected skin surface may be envisioned. For example, and as seen in FIG. 12 , the solution 12 may be applied by spraying. FIGS. 13 and 14 , illustrate the solution 12 applied by way of a hoop device 20 inserted into a container 13 holding the solution 12 . As further seen in FIG. 14 , the hoop device 20 forms and retains a film 22 of solution 12 while the user inserts a selected skin surface, seen as a hand 11 in this view, into the film 22 .
[0044] The novel solution 12 may also be applied to the skin as a surgical prep solution that will also bind any bacteria to create a biofilm into the skin thereby decreasing contamination. The view of FIG. 15 illustrates a first step for applying the solution 12 in this manner, and shows an applicator device 24 transferring the solution 12 to a selected skin surface, seen as a hand 11 .
[0045] Yet another method for applying the solution 12 to a selected skin portion may be seen in FIG. 16 . In this view, the solution 12 is illustrated as a film 22 that may be draped over the hand 11 , or other skin surface.
[0046] The present invention may be formulated from any material that will provide the necessary protective coating while providing an improved tactile feeling as compared to prior art gloves. For example the material may be a silicone polymer or a combination of silicone, and other materials such as an antiseptic, antimicrobial, antibiotic, or other skin sealants such as collodion or cyanoacrylates. Other examples of acceptable coating materials include polymers, such as a polyester material, a PEG material, a polyvinyl material, a nylon material, synthetic rubber, a polypropylene material, or other material that is capable of forming a surgical hand coating 14 and that will form the necessary artificial barrier according to the present invention. The material will allow for a surgical hand coating 14 that is flexible when applied to the user's hands so as to not crack, break, or rupture during a surgical procedure, examination or other manual uses. The material will also be thin enough when dried so that the user will have increased feel when compared to prior art gloves. As mentioned, the specific material to be used as a coating may be a single agent such as a silicone or other plastic polymer or a may be combination of materials including antiseptics such as those marketed under the names CHLORAPREP®, HIBICLENS®, BETADINE®. Other alcohols and antibiotics that may further suppress bacteria may be used in combination with other materials such as flexible Collodion, ether free Collodion, cyanoacrylates such as those used in SUPER GLUE®, and DERMABOND® materials. Any of these combinations may also be applied as a thin film or plastic polymer.
[0047] The prior art does not provide a method wherein a surgical coating is provided that will provide a barrier against bacteria and other contaminants, without the requirement of an external glove or other materials to be used in concert with the surgical hand coating 14 . Prior art gloves 10 are pre fit and preformed versus the present invention of an application of a solution or suspension that is allowed to bind to the skin and provide a custom fit physical barrier to the transgressions of bacterial or contamination and will protect both the patient or the client as well as the physician, surgeon or user.
[0048] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention. | A protective coating solution, liquid, gel, or film and a method of using such a material to provide a sterile covering for fingers, hands, arms or other selected skin surface for use as a glove substitute. | 0 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention was made with support from the government of the United States of America under Contracts F49620-97-C-0064, F49620-97-1-0307, F49620-97-1-0491, F49620-97-C-0064, F49620-98-C-0059, F49620-98-C-0077, F49620-99-0040 awarded by the United States Air Force. The government of the United States of America h as certain rights in this invention as provided by these contracts.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a new class of high hyperpolarizability organic chromophores and a process for synthesizing the same and, more particularly, pertains to polymeric electro-optic modulators and switches prepared by incorporating organic π-electron chromophores covalently into electrically-poled polymeric materials.
2. Description of the Related Art
Numerous materials have been proposed for use in electro-optic devices. These include inorganic materials such as lithium niobate, semiconductor materials such as gallium arsenide, organic crystalline materials, organic materials prepared by sequential synthesis methods, and electrically-poled polymer films containing organic chromophores incorporated either physically to form composites or chemically to form homopolymer materials. A general review of nonlinear optical materials and their technological applications is provided in L. Dalton, "Nonlinear Optical aterials", Kirk-Othmer Encyclopedia of Chemical Technology, 4th Edition, Volume 17 (John Wiley & Sons, New York, 1995) pp. 288-302; in H. S. Nalwa and S. Miyata, Nonlinear Optics of Organic Molecules and Polymers, (CRC Press, Boca Raton, 1997) p. 1-884; in P. N. Prasad and D. J. Williams, Introduction to Nonlinear Optical Effects in Molecules and Polymers, (John Wiley & Sons, New York, 1991; and in D. M. Burland, "Second-Order Nonlinearity in Poled Polymer Systems", Chemical Reviews, Vol. 94, pages 31-75 (1994)).
Electro-optic materials contain highly polarizable electrons. When an electric field is applied to these materials, the electron polarization changes significantly resulting in an increase in index of refraction of materials and a decrease in the velocity of light passing through the materials. This electric field-dependent material index of refraction can be used to impose electric signals onto optical signals, to switch optical signals in a local area network, or to steer a beam of light. The most commonly used material is currently lithium niobate. This material possesses an electro-optic coefficient on the order of 35 pm/V which results in a typical drive voltage (called V.sub.π --the voltage required to produce a π phase shift of light) of on the order of 5 volts. Lithium niobate has a high dielectric constant which results in velocity mismatch of electric and optical waves propagating in the material. This mismatch necessitates a short interaction length (making reduction of drive voltage by increasing device length unfeasible) and limits the bandwidth of the device, for example, a one centimeter electro-optic modulator constructed from lithium niobate typically has a bandwidth of less than 10 Gigahertz. As lithium niobate is a crystalline material, integration with semiconductor electronics and silica fiber optics typically requires sophisticated coupling techniques such as flip-chip bonding and in-diffusion. An electro-optic material that does not suffer from the foregoing limitations would be very desirable.
OBJECTS AND SUMMARY OF THE INVENTION
Thus, it is an object of the present invention to provide an electro-optic material that does not suffer from the limitations of materials such as lithium niobate.
Another object is to provide a new class of high hyperpolarizability organic chromophores and a process for synthesizing the same.
Another object is to provide circuit devices such as an electro-optical modulator employing the new class of high hyperpolarizability organic chromophores.
Putative advantages of organic chromophore-containing polymeric electro-optic materials include a bandwidth significantly in excess of 100 Gigahertz for a one centimeter device and ease of integration with semiconductor electronics (See, L. Dalton et al., "Synthesis and Processing of Improved Organic Second-Order Nonlinear Optical Materials for Applications in Photonics", Chemistry of Materials, Vol. 7, No. 6, pages 1060-1081 (1995), incorporated herein by reference). Also, unlike inorganic materials, chromophore-containing polymeric materials afford the opportunity for systematic improvement of material electro-optic activity by design and development of new chromophores and by development of improved processing strategies (See: A. W. Harper et al., "Translating Microscopic Optical Nonlinearity into Macroscopic Optical Nonlinearity: The Role of Chromophore-Chromophore Electrostatic Interactions", Journal of the Optical Society of America B, Vol. 15, No. 1, pages 329-337 (1998); L. Dalton et al., "The Role of London Forces in Defining Noncentrosymmetric Order of High Dipole Moment-High Hyperpolarizability Chromophores in Electrically Poled Polymeric Thin Films", Proceedings of the National Academy of Sciences USA, Vol. 94, pages 4842-4847 (1997), incorporated herein by reference).
For an organic chromophore to be useful for processing into a hardened polymeric electro-optic material, the chromophore should possess large molecular optical nonlinearity, called hyperpolarizability β, should possess chemical and thermal stability, and should exhibit a small optical absorption coefficient (optical loss) at the intended operating wavelength. Virtually all organic materials, exhibit low dielectric constants and approximately satisfy the condition that n 2 ≈ε where n is the index of refraction and ε is the dielectric constant; thus, all organic electro-optic materials will result in wide bandwidth (greater than 100 Gigahertz devices as far as electro-optic materials are concerned). A commonly employed figure of merit used to compare organic chromophores has been μβ where μ is the chromophore dipole moment and β is the molecular first hyperpolarizability of the chromophore (See: A. W. Harper et al., "Translating Microscopic Optical Nonlinearity into Macroscopic Optical Nonlinearity: The Role of Chromophore-Chromophore Electrostatic Interactions", Journal of the Optical Society of America B, Vol. 15, No. 1, pages 329-337 (1998); L. Dalton et al., "The Role of London Forces in Defining Noncentrosymmetric Order of High Dipole Moment-High Hyperpolarizability Chromophores in Electrically Poled Polymeric Thin Films", Proceedings of the National Academy of Sciences USA, Vol. 94, pages 4842-4847 (1997), incorporated herein by reference). Previously, it has been impossible to prepare chromophores with μβ values in excess of 10,000×10 -48 esu which satisfy the auxiliary requirements of thermal and chemical stability and of low optical loss at telecommunication wavelengths of 1.3 and 1.5 microns. Moreover, chromophores characterized by large μβ values also exhibit large intermolecular electrostatic interactions leading to intermolecular aggregation and associated light scattering leading to unacceptably high values of optical loss at operating wavelengths (See: A. W. Harper et al., "Translating Microscopic Optical Nonlinearity into Macroscopic Optical Nonlinearity: The Role of Chromophore-Chromophore Electrostatic Interactions", Journal of the Optical Society of America B, Vol. 15, No. 1, pages 329-337 (1998); L. Dalton et al., "The Role of London Forces in Defining Noncentrosymmetric Order of High Dipole Moment-High Hyperpolarizability Chromophores in Electrically Poled Polymeric Thin Films", Proceedings of the National Academy of Sciences USA, Vol. 94, pages 4842-4847 (1997), incorporated herein by reference).
Once a chromophore of appropriate optical nonlinearity (μβ), optical absorption, and stability (both chemical and thermal) has been identified, the material must be processed into a hardened polymeric materials containing acentrically-aligned chromophores. The hardened material, in turn, is translated by reactive ion etching or photolithography, for example, into buried channel waveguide structures which can be integrated with appropriate drive electronics and silica fiber transmission lines (See, L. Dalton et al., "Synthesis and Processing of Improved Organic Second-Order Nonlinear Optical Materials for Applications in Photonics", Chemistry of Materials, Vol. 7, No. 6, pages 1060-1081 (1995), incorporated herein by reference).
To withstand processing conditions (the deposition of metal electrodes) and operational conditions (operation optical power levels at 1.3 and 1.5 microns), chromophore-containing polymer materials must be hardened subsequent to electric field poling to withstand temperatures of 90° C. or greater. Chromophores must be modified with reactive functionalities (e.g., hydroxyl groups) which permit processing into hardened polymer matrices (See, L. Dalton et al., "Synthesis and Processing of Improved Organic Second-Order Nonlinear Optical Materials for Applications in Photonics", Chemistry of Materials, Vol. 7, No. 6, pages 1060-1081 (1995), incorporated herein by reference). When thermosetting (addition or condensation) chemical reactions are employed to lock-in electric field poling-induced acentric order, a stepped poling protocol where temperature and electric field strength is increased in successive steps is frequently required to optimize material electro-optic activity (See, S.Kalluri et al., "Improved Poling and Thermal Stability of Sol-Gel Nonlinear Optical Polymers," Applied Physics Letters, Vol. 65, pages 2651-2653 (1994), incorporated herein by reference).
By optimizing the conditions of reactive ion etching, low loss optical waveguides can be fabricated in polymeric waveguides containing acentrically order organic chromophores (See: W. H. Steier et al., "Applications of Electro-Optic Polymers in Photonics," Materials Research Society Symposium Proceedings, Vol. 413, Electrical, Optical and Magnetic Properties of Organic Solid State Materials (Materials Research Society, Pittsburgh, 1996) pages 147-58; A. Chen et al., "Optimized Oxygen Plasma Etching of Polyurethane Based Electrooptic Polymers for Low Loss Waveguide Fabrication," Journal of the Electrochemical Society, Vol. 143, pages 3648-3651 (1996), incorporated herein by reference). A variety of other techniques can also be employed to fabricate buried channel active electro-optic waveguides including laser ablation, multi-color photolithography, and spatially selective poling (See, L. Dalton et al., "Synthesis and Processing of Improved Organic Second-Order Nonlinear Optical Materials for Applications in Photonics", Chemistry of Materials, Vol. 7, No. 6, pages 1060-1081 (1995), incorporated herein by reference).
The integration of polymeric waveguide electro-optic modulators with semiconductor very large scale integration (VLSI) circuitry demonstrates the putative advantage of polymeric electro-optic materials for integration with semiconductor electronics (See: S. Kalluri et al., "Integration of Polymer Electrooptic Devices on Non-Planar Silicon Integrated Circuits," Proceedings of the SPIE, Vol. 2527, pages 375-383 (1995); S. Kalluri et al., "Monolithic Integration of Waveguide Polymer Electrooptic Modulators on VLSI Circuitry," IEEE Photonics Technology Letters, Vol. 8, pages 644-646 (1996), incorporated herein by reference).
Low loss coupling schemes for coupling polymeric modulator waveguides to silica fiber transmission lines can also be employed (See, A. Chen et al., "Integrated Polymer Waveguide Mode Size Transformer with a Vertical Taper for Improved Fiber Coupling," Optoelectronic Interconnects and Packaging IV, eds., R. P. Chen and P. S. Gulfoyle, Proceedings of the SPIE, Vol. 3005, pages 65-76 (1997), incorporated herein by reference).
The putative large operational bandwidth of polymeric modulators has been demonstrated in a series of experiments establishing ever increasing bandwidth records and leading to the current record of 113 Gigahertz (See: D. G. Girton et al., "20 GHz Electro-Optic Polymer Mach-Zehnder Modulator", Applied Physics Letters, Vol. 58, pages 1730-1732 (1991); W. Wang et al., "40-GHz Polymer Electrooptic Phase Modulators", IEEE Photonics Technology Letters, Vol. 7, pages 638-640 (1995); D. Chen et al., "High-Bandwidth Polymer Modulators," Proceedings of the SPIE, Vol. 3007, pages 314-317 (1997); D. Chen et al., "Demonstration of 110 GHz Electro-Optic Polymer Modulators," Applied Physics Letters, Vol. 70, pages 2082-2084 (1997), incorporated herein by reference).
The present invention provides a new level of performance of polymeric electro-optic modulators surpassing lithium niobate and semiconductor material modulators in terms of electro-optic coefficient as well as material defined bandwidth performance. The material class that represents the materials basis of this disclosure is characterized not only by exceptional optical nonlinearity (μβ values in excess of 15,000×10 -48 esu) but also by exceptional (particularly for a high μβ chromophore) thermal and chemical stability and by low absorption loss at 1.3 and 1.5 micron wavelengths (communication band wavelengths).
These materials are readily fabricated into electro-optic modulator devices using protocols previously developed for other chromophores. The materials are fully amenable to all processing steps necessary for the fabrication of devices. The materials exhibit improved photochemical stability compared to commonly used Disperse Red chromophore-containing materials (See, Y. Shi et al., "Fabrication and Characterization of High-Speed Polyurethane-Disperse Red 19 Integrated Electro-Optic Modulators for Analog System Applications," IEEE Journal of Selected Topics in Quantum Electronics, Vol. 2, pages 289-299 (1996), incorporated herein by reference).
According to the present invention, these materials can be employed not only in conventional electro-optic modulator devices configurations but also in devices employing a constant bias field which permits the full potential of the materials to be demonstrated. Examined as composites in poly(methylmacrylate), PMMA, chromophores of the class which are designated FTC exhibit electro-optic coefficients greater than 50 pm/V at 1.064 microns. In hardened poly(urethane), PU, materials electro-optic coefficients greater than 40 pm/V are observed at 1.064 microns. Slightly smaller electro-optic coefficients are observed at 1.3 microns consistent with theoretical expectations. An optical loss on the order of 0.75 dB/cm is observed for the FTC-PMMA materials while optical loss in the range 1-2 dB/cm is observed for hardened FTC-PU materials; the precise value of optical loss depends upon processing protocols employed.
The present invention embodies a new theory of intermolecular interactions which has been developed and employed to optimize the design of second order nonlinear optical chromophores. Explicitly, the detailed shape of molecules and the full spatial anisotropy of intermolecular interactions is taken into account to calculate the predicted variation of macroscopic materials electro-optic coefficients versus chromophore number density in the host polymer matrix. A quantitative prediction of the maximum electro-optic coefficients can be obtained for a given chromophore π-electron structure and molecular shape. Chromophores have been systematically modified with alkyl, aryl, and isophorone substituents to systematically improve macroscopic electro-optic coefficients and to minimize optical loss from aggregation.
The new class of organic chromophores exhibiting exceptional molecular optical nonlinearity, thermal stability, and low optical absorption at telecommunication wavelengths are processed into hardened electro-optic polymers which lead to improved electro-optic device performance. In particular, bandwidths of greater than 100 Gigahertz, drive voltages of less than 5 volts, and optical loss of less than 1.5 dB/cm are achieved in the worst case performance. The method of the present invention achieves hardened material lattices to lock-in poling induced electro-optic activity. Another new device configuration for electro-optic modulators employs a constant dc electric bias, which permits the full potential of new electro-optic materials to be realized.
An organic chromophore, in accordance with a specific illustrative embodiment of the present invention, is a chromophore processed into a hardened material lattice suitable for a wave guide structure, with the chromophore incorporating at least one organic substituent and being formed in consideration of molecular shapes and a spatial anisotropy of intermolecular interactions.
In a further aspect of the present invention, the at least one organic substituent comprises alkyl, aryl, and isophorone groups.
In an alternative further aspect of the present invention, the chromophore is acentrically-aligned.
In another aspect of the present invention, a composite including the organic chromophore further includes a polymer material such as a poly(methylmacrylate), polyimide, polyamic acid, polystyrene, polycarbonate or polyurethane.
In another aspect of the present invention, a modulator device includes single elements or arrays of phase and amplitude optical modulators formed from high hyperpolarizability organic chromophores, the modulators operating at frequencies from DC to at least 120 GHz.
In another aspect of the present invention, a modulator device includes a combination of phase and amplitude modulators formed from high hyperpolarizability organic chromophores, the modulators being configured to perform signal processing such as microwave phase shifting for radars, high-speed optical A/D conversion and high-speed optical switches.
In another aspect of the present invention, a process for synthesizing an organic chromophore includes the step of forming an organic chromophore within a hardened polymer lattice by incorporating hydroxyl substituents adapted to cause a thermosetting reaction to establish an electric field poling-induced acentric order.
In another aspect of the present invention, a process for synthesizing an organic chromophore includes the step of forming an organic chromophore with two photon crosslinking reaction chemistry to establish an electric field poling-induced acentric order.
In another aspect of the present invention, a process for synthesizing an organic chromophore includes the step of forming an organic chromophore within a host polymer matrix in consideration of a detailed shape of molecules and a full spatial anisotropy of intermolecular interactions to provide a predicted variation of macroscopic materials electro-optic coefficients versus chromophore number density in said host polymer matrix. The modulator can be fabricated by spinning the organic chromophore and host polymer on any substrate. In applications requiring a conformal, or thin, device, the substrate can be a flexible substrate such as Mylar®.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects, features and advantages of the invention will become readily apparent upon reference to the following detailed description when considered in conjunction with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof, and wherein:
FIG. 1 shows the FTC chromophore class structures according to an exemplary preferred embodiment of the present invention. The R and R' groups have been systematically modified according to the process of the present invention to achieve optimum electric field poling efficiency and thus maximum electro-optic coefficients.
FIGS. 2 and 3 show the synthesis of a representative FTC chromophore.
FIG. 4 shows typical optical, nonlinear optical, and thermal data obtained for a representative FTC chromophore.
FIG. 5 shows the determination of optical and nonlinear optical properties of FTC/PMMA composite materials.
FIG. 6 provides a tabulation of measured electro-optic coefficient versus chromophore loading (chromophore number density). Also, given is the index of refraction versus chromophore loading which establishes that a solid solution is maintained over the concentration range studied.
FIG. 7 shows the comparison of theoretical (lines) electro-optic data calculated for three different molecular models with experimental data (symbols).
FIG. 8 shows the synthesis of a hardened PU-FTC material.
FIG. 9 summarizes optical and nonlinear optical data obtained for the PU-FTC material. Also shown is the thermal stability of the PU-FTC material obtained by monitoring second harmonic generation as a function of increasing the temperature.
FIG. 10 illustrates an electro-optic device employing a constant electric field bias.
FIG. 11 illustrates the synthesis of an isophorone containing FTC chromophore.
FIG. 12 shows a Mach Zehnder modulator incorporating the FTC materials of the present invention.
FIG. 13 shows the extension of the devices of the present invention to frequencies in excess of 100 GHz. using integrated microwave structures and the use of arrays of these devices.
FIG. 14 shows the use of the materials of the present invention (in the form of microstrip lines) in a microwave phase shifter of the type employed in optically controlled phased array radars.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A new class of nonlinear optical chromophores shown in FIG. 1 have been synthesized (see FIGS. 2 and 3 for the general synthesis scheme). The detailed synthesis is described as follows: ##STR1## Synthesis of 2-Dicyanomethylen-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran
In a 1 L round-bottomed flask, a solution of sodium ethoxide was prepared by adding 2.3 g (0.1 mole) sodium to 200 ml ethanol. To this solution 10.4gram (0.1 mole) of 3-methyl-3-hydroxy-2-butanone and 13.2 grams (0.2 mole) of malononitrile were added. The resulting mixture was stirred for 20 h at room temperature. After concentration in vacuo, the residue was acidified with conc. HCl to adjust the pH to 4-5. The crude precipitate was filtered and recrystallized from ethanol to give 7.2 g pure furan derivatives 1 as pale or light yellow needles (36w). Melting point: 198° C. 1 H NMR (Bruker 250, ppm, in chloroform): 2.37 (s, 3H), 1.64 (s, 2H). 13 C NMR (Bruker 250, ppm, in chloroform): 185.0, 177.3, 112.2, 111.5, 110.0, 103.6, 101.3, 23.5, 14.2.
Synthesis of the FTC Chromophore (4)
The synthesis of the donor-bridge aldehyde for chromophore FTC (4) followed the procedures established by the inventors of the present invention (See, F. Wang, Design, Synthesis, and Characterization of Novel Organic Chromophores and Polymers for Electro-Optic Modulation, Ph.D. Thesis, University of Southern California, Los Angeles, 1998, incorporated herein by reference). 1 H NMR of intermediates and the detailed procedure for the intermediates is described as follows:
3,4-Dibromothiophene: 1 H NMR (Bruker 250, CDCl 3 ) 7.28 s (2H).
3,4-Dibutylthiophene: 1 H NMR (Bruker 250, CDCl 3 ) 6.8 9 (s, 2H) 2.51 (t, 4H), 1.61 (m, 4H), 1.39 (m, 4H), 0.952 (t, 6H).
2,5-Dibromo-3,4-dibutylthiophene: 1 H NMR (Bruker 250, CDCl 3 ) 2.52 (t, 4H), 1.43 (m, 8H), 0.952 (t, 6H).
2-Bromo-3,4-dibutyl-thiophene-5-carbaldehyde: 1 H NMR (Bruker 250, CDCl 3 ) 9.89 (s, 1H), 2.86 (t, 4H), 2.51 (m, 4H), 1.43 (M, 4H), 0.952 (t, 6H).
2-Bromo-3,4-dibutyl-5-hydroxymethyl-thiophene: 1 H NMR (Bruker 250, CDCl 3 ) 4.68 (s, 2H), 2.51 (m, 4H), 1.69 (s, 1H), 1.42 (m, 8H), 0.952 (t, 6H).
2-Bromo-3,4-dibutyl-5-thienylmethyltributylphosphonium bromide: 1 H NMR (Bruker 250, CDCl 3 ) 4.28 (d, 2H), 2.69 (m, 2H), 2.55 (m, 8H), 1.49 (m, 14H), 1.31 (m, 6H), 0.986 (t, 9H), 0.883 (t, 6H).
4-[N,N-di(2-acetoxyethyl)amino]-benzaldehyde: 1 H NMR (Bruker 250, ppm, in CDCl 3 ) 9.71 (s, 1H), 7.70 (d, 2H), 6.78 (d, 2H), 4.24 (t, 4H), 3.68 (4H), 2.00 (s, 6H).
4-{N,N-di-[2-(1,1,2,2,-tetramethyl-1-silapropoxy)ethyl]aminobenzaldehy-de: 1 H NMR (Bruker 250, ppm, in CDCl 3 ) 9.70 (s, 1H), 7.68 (d, 2H), 6.73 (d, 2H), 3.78 (t, 4H), 3.60 (4H), 0.88 (s, 18H), 0.03 (s,12H).
2-{trans-4-[N,N-di[2-(1,1,2,2,-tetramethyl-1-silapropoxy)ethyl]amino-phenylene}-3,4-dibutyl-5-bromo-thiophene (6): 37.25 grams of 4-di(2-(1,1,2,2,-tetramethyl-1-silapropoxy)ethyl)-aminobenzaldehyde (85.1 mmol) and 250 ml (0.2837 M) of 2-bromo-3,4-dibutyl-5-thienylmethyltributylphosphonium bromide (70.9 mmol) were mixed in 200 mL ethanol. The mixture was heated to 80° C. 106 mL (1M, 1.5 eq.) sodium ethoxide in ethanol was added drop-wise, at 80° C. The reaction mixture was kept refluxing for 48 hours, before it was poured into 600 ml water. The crude product was extracted from aqueous phase with ether (2×200 mL) and dried over MgSO 4 . After concentration via rotavap, the crude product was eluted down from a column with 5% ethyl acetate and hexane mixture as eluent to yield 30 grams of thick yellow oil (59.7%). 1 H NMR (Bruker 250, ppm, in CDCl 3 ): 7.29 (d, J H-H =8.5, 2H), 6.93 (d, J H-H =15.6, 1H), 6.66 (d, J H-H =9.2, 2H), 3.75 (t, J H-H =6.8, 4H), 3.52 (t, J H-H =6.3, 4H), 0.88 (s, 18H), 0.03 (s, 12H).
Synthesis of 2-[trans-(4-N,N-di(2-hydroxyethyl)-amino)-phenylene-(3,4-dibutyl-thien-5]-al (3): 26 grams (36.7 mmol) of compound 6 was dissolved in 200 ml tetrahydrofuran and cooled down to -78° C., using acetone/dry-ice bath. 56 mL (1.5 M, 84.3 mmol) of t-butyllithium in hexane was added drop-wise at -78° C. Dark blue color was observed at the end of the addition. The reaction mixture was warmed up to -30° C. slowly and 20 mL of dimethylformamide was added. After stirring for half hour at room temperature, 150 mL 10% HCl solution was added to the reaction mixture. The mixture was stirred at room temperature for 4 hours. The organic solvent was evaporated and the residue was diluted with 150 mL water and extracted with hexane (2×150 mL). The aqueous was adjusted to pH=8-9. The crude aldehyde was extracted out with ether. Column chromatography afforded 12.3 grams of dark red solid (78%). 1 H NMR (Bruker 250, ppm, in DMSO-d 6 ): 9.93 (s, 1H), 7.45 (d, J H-H =9.0, 2H), 7.13 (d, J H-H =16.0, 1H), 7.02 (d, J H-H =16.2, 1H), 6.69 (d, J H-H =8.8, 2H), 4.77 (t, J H-H =5.3, 2H),), 3.52 (3, J H-H =5.5, 4H), 3.45 (t, J H-H =5.0, 4H), 2.86 (t, J H-H =6.8, 2H), 2.66 (t, J H-H =6.2, 2H), 1.39 (m, 8H), 0.91 (m, 6H). 13 C NMR (Bruker 250, ppm, in DMSO-d 6 ): 182.3, 153.1, 147.5, 140.1, 133.3, 132.7, 128.6, 122.6, 114.2, 111.4, 58.1, 53.1, 34.0, 32.9, 22.1, 22.0, 13.7.
2-dicyanomethylen-3-cyano-4-{2-[trans-(4-N,N-di(2-hydroxyethyl)amino)-phenylene-(3,4-dibutyl)thien-5]-E-vinyl}-5,5-dimethyl-2,5dihydrofuran (monomer 7): 1 g (2.33 mmol) of aldehyde 3 and 0.62 grams (3.11 mmol) of acceptor 1 were mixed in 3 mL tetrahydrofuran and 3 mL CHCl 3 with one drop of triethylamine as catalyst. The mixture was kept at reflux for overnight. Reaction progress was checked with TLC until almost all the starting material was consumed. The solvent was removed via rotary evaporation. Column chromatography with 40% acetone in methylene chloride as eluent afforded 1.17 grams of pure product as dark purple solid (77.5%). 1 H NMR (Bruker 250, ppm, in DMSO-d 6 ): 8.15 (d, J H-H =15.3, 1H), 7.49 (d, J H-H =9.0, 2H), 7.21 (d, J H-H =15.8, 1H), 7.10 (d, J H-H =15.5, 1H), 6.72 (d, J H-H =9.0, 2H), 6.58 (d, J H-H =15.0, 1H), 4.78 (t, J H-H =5.0, 2H), 3.54 (t, J H-H =5.3, 4H), 3.49 (m,4H), 2.71 (m, 4H), 1.71 (s, 6H), 1.41 (m, 8H), 0.91 (m, 6H). 13 C NMR (Bruker 360, ppm, in DMSO-d 6 ): 177.3, 174.3, 153.9, 149.0, 148.8, 141.5, 137.6, 134.5, 131.8, 129.1, 123.1, 114.2, 113.3, 112.5, 112.4, 111.6, 110.6, 98.4, 93.1, 58.2, 53.2, 51.9, 33.6, 32.8, 26.7, 25.7, 25.3, 22.3, 22.0, 13.8, 13.7. Melting Point (DSC, 10°/min.): 183° C. T d (DSC, 10°/min): 258° C. λ max : 657 nm (in CHCl 3 ). Elemental analysis: Found, C 70.54; H 6.83; N 9.00. Theoretical, C 70 .79; H 6.93; N 9.17.
2-dicyanomethylen-3-cyano-4-{2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)thien-5]-E-vinyl}-5,5-dimethyl-2,5dihydrofuran (4): 0.26 grams (0.425 mmol) of Chromophore 9 was dissolved in 3 mL of acetic anhydride and heated for 3 hours at 60° C. Acetic anhydride was removed under vacuum. Column chromatography with 20% hexane in ethyl acetate afford 0.29 grams of analytical pure product (97w). 1 H NMR (Bruker 250, ppm, in CDCl 3 ): 8.14 (d, J H-H =15.5, 1H), 7.39 (d, J H-H =8.5, 2H), 7.03 (s, 2H, strong second order effect), 6.76 (d, J H-H =8.8 2H), 6.38 (d, J H-H =15.5, 1H), 4.24 (t, J H-H =6.3, 4H), 3.66 (t, J H-H =5.8, 4H), 2.64 (m, 4H), 2.04 (s, 6H), 1.69 (s, 6H), 1.45 (m, 8H), 0.95 (m, 6H). C NMR (Bruker 250, ppm, in CDCl 3 ): 173.0, 170.9, 154.0, 148.8, 148.0, 142.0, 138.0, 134.0, 132.5.8, 128.9, 125.1, 115.3, 112.6, 112.2, 111.9, 111.7, 110.2, 96.7, 93.7, 61.2, 60.4, 49.7, 34.0, 33.1, 27.6, 26.6, 26.4, 22.9, 22.7, 20.9, 13.9. Melting point (DSC, 10°/min.): 130.3° C. T d (DSC, 10°/min): 310.6° C. λ max : 653 nm (in CHCl 3 ).). Elemental analysis: Found, C 69.35; H 6.69; N 7.92. Theoretical, C 69.14; H 6.67; N 8.06.
Diethyl 2-thiophenemethylphosphonate: 1 H NMR (Bruker 250, ppm, in CDCl 3 ) 7.10 (m, 1H), 6.91 (m, 2H), 4.00 (m, 4H), 3.30 (d, 2H), 1.21 (t, 6H).
4-[N,N-di(2-acetoxyethyl)amino]phenylene-2-thiophene (8): The key intermediate 8 was synthesized as the following: 8.5 g (71.6 mmol) sodium t-butoxide in 25 ml THF was added drop-wise to a mixture of 17.5g (59.7 mmol) 4-[N,N-di(2-acetoxyethyl)amino]-benzaldehyde and 15.4 g (65.7 mmol) diethyl 2-thiophene-methylphosphonate in 30 mL THF at 0° C. The reaction mixture was stirred overnight in an unattended ice-bath, then was poured into 800 ml cold water. The aqueous mixture was extracted with methylene chloride and dried over MgSO 4 . Evaporation of the solvent after filtration gave the desired donor-bridge. The acetyl groups were hydrolyzed by the conditions of the Horner-Emmons reaction. Reprotection was carried out in acetic anhydride at 45° C. for three hours. Column chromatography over silica gel, eluting with 30% ethyl acetate in hexanes afforded 14.5 g pure product. 1 H NMR (Bruker 250, ppm, in CDCl 3 ): 7.34 (d, 2H), 7.12 (dd, 1H), 7.04 (d, 1H), 6.98 (d, 1H), 6.95 (d, 1H), 6.83 (d, 1H), 6.73 (d, 2H), 4.24 (t, 4H), 3.63 (t, 4H), 2.04 (s, 6H). 13 C. NMR (Bruker 250, ppm, in CDCl 3 ): 170.9, 146.7, 143.6, 128.2, 127.7, 127.5, 126.1, 124.8, 123.2, 118.2, 112.2, 61.3, 49.7, 20.9.
Synthesis of trans -[(N, N-di(2-acetoxyethyl)amino)phenylene-2-thien-5-al (9): In a 200 mL 3-necked round-bottomed flask equipped with a stirring bar, addition funnel and argon inlet, 16.04 g (0.217 mole; 99%) of DMF was cooled in an ice-bath. 12.4g (0.08 mole, 99%) of POCl 3 was added drop-wise through the addition funnel. The mixture was stirred at ice-bath temperature for 1 hour, then at room temperature for another hour. 27.6 g (0.0724 mole, 98%) of compound 7 in 30 mL 1,2-dichloroethane was added dropwise. The funnel was replaced with a condenser after the addition. The reaction mixture was heated at 90° C. for three hours and then cooled slightly before it was poured into 600 mL ice-water. The aqueous layer was extracted with methylene chloride. The organic portion was washed with saturated NaHCO 3 solution and dried over MgSO 4 . Immediate column chromatography afforded 12.5g (43%) product as orange-red waxy solid. 1 H NMR (Bruker 250, ppm, in CDCl 3 ): 9.77 (s, 1H), 7.58 (d, 1H), 7.34 (d, 2H), 7.04 (d, 1H), 7.01 (d, 1H), 6.94 (d, 1H), 6.66 (d, 2H), 4.20 (t, 4H), 3.55 (t, 4H), 2.02 (s, 6H). 13 C NMR (Bruker 250, ppm, in CDCl 3 ): 182.2, 170.8, 154.0, 148.0, 140.0, 137.6, 133.3, 128.5, 125.0, 123.7, 116.0, 111.7, 61.4, 48.5, 45.2, 32.1, 20.8, 12.1.
Synthesis of 2-dicyanomethylen-3-cyano-4-{2-[E-(4-N,N-di(2-acetoxyethyl)amino)phenylene-2-thien-5]-E-vinyl}-5,5-dimethyl-2,5-dihydrofuran (5): The condensation reaction between the donor-bridge aldehyde (9) and the acceptor (1) can be carried out in both ethanol (with piperidine as catalyst) and chloroform (with triethylamine as catalyst). Thus, 0.6 g (1.5 mmol) of aldehyde 9 and 0.36 g (1.8 mmol) of acceptor 1 and one drop of triethylamine was mixed in 5 ml chloroform. The reaction mixture was refluxed under argon for approximately ten hours. The mixture was loaded to a column and eluted with 50% ethyl acetate in hexane. 0.33g (38%) of dark blue solid was yielded. 1 H NMR (Bruker 360, ppm, in DMSO-d 6 ): 8.09 (d, J H-H =16.2, 1H), 7.74 (d, J H-H =3.6, 1H) 7.48 (d, J H-H =8.6, 2H), 7.29 (d, J H-H =16.2, 1H), 7.26 (d, J H-H =5.0, 1H), 7.19 (d, J H-H =15.8, 2H), 6.81 (d, J H-H =9.0, 2H), 6.65 (d, J H-H =15.5, 2H), 4.16 (t, J H-H =6.1, 4H), 3.65 (t, J H-H =5.8, 4H), 1.98 (s, 6H), 1.78 (s, 6H),. 13 C NMR (Bruker 250, ppm, in DMSO-d 6 ): 178.4, 176,9, 176.8, 174.5, 170.4, 153.1, 148.2, 140.4, 138.8, 137.7, 133.9, 128.9, 127.8, 124.0, 116.6, 113.0, 112.3, 111.9, 111.2, 98.6, 96.6, 61.0, 59.7, 52.8, 48.8, 25.5, 20.7. Melting point (DSC): 174° C. Td (DSC): 290° C. λ max : 629 nm (in CHCl 3 ). Elemental analysis: Found, C 64.34; H 5.35; N 8.93. Theoretical, C 65.96; H 5.19; N 9.62.
Compound 10. 1 H NMR (Bruker 360, ppm, in CDCl 3 ): 7.57 (d, J=15.8, 1H), 7.51 (d, J=9.36, 2H), 6.70 (d, J=15.1, 1H), 6.67 (d, J=8.64, 2H), 4.24 (t, J H-H =6.3, 4H), 3.66 (t, J H-H =5.8, 4H) 2.04 (s, 6H), 1.72 (s, 6H).
The hydroxyl terminated versions of the FTC chromophore (either di- or tri-functionalized chromophores) are processed into hardened polymer lattices with acentrically ordered chromophores illustrated in FIG. 8.
FIG. 4 shows typical optical, nonlinear optical, and thermal data obtained for a representative FTC chromophore. Hyperpolarizability, β, was determined by hyper-Rayleigh scattering while the product of dipole moment and hyperpolarizability, μβ, was determined by electric field induced second harmonic generation. Thermal stability was determined by thermal gravimetric analysis and differential scanning calorimetry.
FIG. 5 shows the determination of optical and nonlinear optical properties of FTC/PMMA composite materials. The change in optical spectrum with poling (black before, red after) permits calculation of the polar order parameter and optical loss is measured by the method of Teng (C.C. Teng, "Precision Measurement of the Optical Attenuation Profile Along the Propagation Path in Thin-Film Waveguides", Applied Optics, Vol. 32, pages 1051-1054 (1993), incorporated herein by reference).
FIG. 6 provides a tabulation of measured electro-optic coefficient versus chromophore loading (chromophore number density). Also, given is the index of refraction versus chromophore loading which establishes that a solid solution is maintained over the concentration range studied.
FIG. 7 shows the comparison of theoretical (lines) electro-optic data calculated for three different molecular models with experimental data (symbols). The theoretical basis of the calculations is described by Dalton (See, L. Dalton et al., "The Role of London Forces in Defining Noncentrosymmetric Order of High Dipole Moment-High Hyperpolarizability Chromophores in Electrically Poled Polymeric Thin Films", Proceedings of the National Academy of Sciences USA, Vol. 94, pages 4842-4847 (1997), incorporated herein by reference).
FIG. 8 shows the synthesis of a hardened PU-FTC material.
FIG. 9 summarizes optical and nonlinear optical data obtained for the PU-FTC material. Also shown is the thermal stability of the PU-FTC material obtained by monitoring second harmonic generation as a function of increasing the temperature.
FIG. 10 illustrates an electro-optic device 1000 employing a constant electric field bias. In the illustrated embodiment, a modulator chip 1002, a fiber 1004, a thermoelectric cooler 1006, a temperature controller 1008, a thermister 1010, and a bias tee 1012 (including a resistor and a capacitor) are configured as shown providing a light output (arrow 1014).
FIG. 11 illustrates the synthesis of an isophorone containing FTC chromophore.
FIG. 12 shows a Mach Zehnder modulator 1200 incorporating the FTC materials of the present invention. In the illustrated embodiment, a Si substrate 1202, an Epoxylite (3 μm) layer 1204, a PU-FTC (1.5 μm) layer 1206, a NOA73 (3.5 μm) layer 1208, a waveguide 1210, and an electrode 1212 are configured as shown with light indicated by arrows 1214, 1216.
FIG. 13 shows the extension of the devices of the present invention to frequencies in excess of 100 GHz. using integrated microwave structures and the use of arrays of these devices.
FIG. 14 shows the use of the materials of the present invention (in the form of microstrip lines) in a microwave phase shifter 1400 of the type employed in optically controlled phased array radars. In the illustrated embodiment of the photonically controlled RF phase shifter 1400, microstrip lines 1402, 1404, a DC control electrode 1406, a DC source 1408, and a photodetector 1410 are configured as shown with light indicated by arrow 1412.
Those skilled in the art will appreciate that various adaptations and modifications of the just described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. | A new class of high hyperpolarizability organic chromophores and a process for synthesizing the same. The chromophores incorporate at least one organic substituent and are formed in consideration of molecular shapes and a spatial anisotropy of intermolecular interactions. The chromophores are processed into hardened material lattices to lock-in poling induced electric-optic activity. Preferred organic substituents are alkyl, aryl, and isophorone groups. A composite including the organic chromophore, in a preferred embodiment, includes a polymer such as a poly(methylmethacrylate), polyimide, polyamic acid, polystyrene, polycarbonate or polyurethane. The optimized chromophores result in hardened electro-optic polymers suitable for electro-optic modulators and other devices such as optical switches. These modulators can be configured to work at high frequencies and in arrays for applications in communications and network connections. In addition, they can be implemented in series and parallel combinations in phased array radar, signal processing and sensor technology applications. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2006/063861, filed Jul. 4, 2006 and claims the benefit thereof. The International Application claims the benefits of German application No. 102005035748.2 DE filed Jul. 29, 2005, both of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The present invention relates to localizing mobile terminals.
BACKGROUND OF INVENTION
[0003] In location/position based applications, e.g. conference management or communication management for hotels, it is necessary to determine the geographical position of associated or assigned mobile terminals. For this purpose the mobile terminals are increasingly equipped with functions with the aid of which they are able to determine their geographical position. For example GPS receivers are integrated in the mobile terminals with the aid of which the geographical position can be determined. Other methods are also used e.g. for determining the position of the corresponding mobile terminal by measuring the levels of different transmission stations. All these methods and functions are initiated by means of queries to the respective mobile terminal, or its position/positional information is interrogated. These queries and interrogations are usually performed by a central device in which the location based applications are realized.
SUMMARY OF INVENTION
[0004] The queries are accordingly issued continuously, i.e. in a defined time schedule. In order to be able to record the geographical position of mobile terminals that are displaced, and particularly those that are displaced relatively rapidly, continuous queries are necessary at short intervals or within a fairly short time schedule. In particular when it is necessary to query a plurality of mobile terminals, this leads to an increased transmission of information, with the transmission systems and the information-processing components of the central device being subjected to a considerable dynamic load and even being overloaded.
[0005] The object underlying the invention is to improve the geographical localization of mobile terminals. This object is achieved by the features of the claims.
[0006] A significant advantage of the inventive methods is that the queries to mobile terminals that are either not displaced or displaced slowly can take place at long intervals and thus the wireless transmission systems and the position- and position-information-processing components of a central device are relieved of a considerable dynamic load. This load-reduction effect is reinforced by most terminals being displaced at low speeds. A further advantage of the inventive methods is that the speed of displacement of the mobile terminals is determined and this information can be provided to the location based applications in addition to the position of the terminals. Applications for which this additional information is advantageous include applications that include roaming functions.
[0007] Advantageous developments of the inventive methods may be found in the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is described in more detail below with reference to two appended drawings, in which
[0009] FIG. 1 shows a topology in which the invention is realized; and
[0010] FIG. 2 shows a flow chart explaining the inventive method to accompany the topology realized in FIG. 1 .
DETAILED DESCRIPTION OF INVENTION
[0011] FIG. 1 shows a communication platform PF in which applications AP for the terminals E 1 . . . En shown are realized. For the exemplary embodiment it is assumed that the whereabouts or geographical position P 1 . . . Pn of the terminals E 1 . . . En and/or of the users of the terminals E 1 . . . En is to be determined for the applications AP in accordance with the inventive methods. Such applications AP include for example a conference application or an application AP for communication in hotels or an application intended for dealing with emergency situations. The platform PF is embodied for example as a server, with such a server mostly being realized by a computer system or a personal computer.
[0012] The terminals E 1 . . . En are represented in the example by cordless terminals which are embodied in accordance with the DECT standard with regard to radio interface and transmission protocol.
[0013] Alternatively other wireless or mobile radio methods are possible in accordance for example with a wireless LAN method or a Bluetooth method or a GPRS method or a UMTS method. The mobile terminals E 1 . . . En can also be hardwired to the platform through a communication network (not shown), whereby the communication networks can be embodied as packet-based or time-division-multiplex-based (not shown).
[0014] In the exemplary embodiment middleware MW is provided in the platform PF for connection of the terminals E 1 . . . En, by means of which the physical and protocol properties are realized in accordance with the terminals E 1 . . . En provided. In the terminals E 1 . . . En conforming to the DECT method according to the exemplary embodiment the physical and protocol DECT interface—indicated in FIG. 1 by the abbreviation DECT—is realized by the middleware MW. The middleware is to be embodied accordingly in the case of other mobile terminals E 1 . . . En.
[0015] For the inventive method it is assumed in the exemplary embodiment that a GPS function GPS (Global Positioning System)—referred to as GPS in FIG. 1 —is used in the terminals E 1 . . . En in order to determine the geographical position P 1 . . . Pn of same. A GPS receiver is provided for this purpose with the aid of which the position P 1 . . . Pn of the terminals E 1 . . . En is determined in accordance with the coordinate system. The position P 1 . . . Pn of the terminals E 1 . . . En is unambiguously determined using the positional information pi established by the GPS function GPS.
[0016] Alternatively level measurements of the received radio signals—not shown—can be performed in order to determine the position P 1 . . . Pn of the terminals E 1 . . . En. The radio signal levels of two radio transmitters are advantageously measured, since the geographical position P 1 . . . Pn of the terminals E 1 . . . En can be determined in this way from the known locations of the radio transmitters and the level of the received radio signals. In hardwired mobile terminals E 1 . . . En the position P 1 . . . Pn of the mobile terminals E 1 . . . En can be determined by establishing at which network access point, the position of which is known, the respective mobile terminal E 1 . . . En is currently connected—not shown in FIG. 1 . If the terminal E 1 . . . En is connected to the platform PF via a communication network, the position P 1 . . . Pn of said terminal E 1 . . . En can be determined with the aid of the communication network components such as switching equipment or gatekeepers, for example, and the positional information pi generated in this way can be forwarded to the platform PF, with the communication network components being interrogated by the platform PF for the position P 1 . . . Pn of the terminals E 1 . . . En. If the terminals E 1 . . . En are connected directly to the platform PF the position P 1 . . . Pn of the terminals E 1 . . . En is determined by the platform PF itself.
[0017] The inventive method described in FIG. 2 using a flow chart is realized in the middleware MW of the platform PF and in the terminals E 1 . . . En principally by technical programming means, with a position routine PR being provided for this purpose in the terminals E 1 . . . En.
[0018] In the flow chart shown in FIG. 2 a terminal E and the platform PF are each indicated by a dash-dotted line, with any one of the terminals E 1 . . . En being represented by the terminal E.
[0019] As has already been stated it is necessary for certain applications AP that the current/updated geographical position P 1 . . . Pn of the mobile terminals E 1 . . . En is determined. For this purpose a query anf is transmitted by the platform PF to the terminal E concerned, with the query anf containing an item of information ip that shows the terminal E concerned that it is to determine its actual position P 1 . . . Pn and generate an item of positional information pi. Upon receipt of the query anf in the terminal E concerned the terminal E determines its geographical position P 1 . . . Pn in accordance with the exemplary embodiment with the aid of the GPS function GPS. The positional information pi determined in this way is transferred/transmitted wirelessly to the platform PF by means of a response res via the DECT function DECT—indicated in FIGS. 1 and 2 by the abbreviation DECT.
[0020] The position P 1 . . . Pn of the terminal E concerned or the terminals E concerned—indicated in FIG. 2 by the abbreviation PER—is determined several times—indicated in FIG. 2 by the abbreviation n×PER, whereby these initial queries anf can be performed at regular i.e. equal intervals t or also irregularly. The speed of displacement kv of the terminal E concerned is determined/calculated using the n transmitted positional information pi in the platform PF. The interval t of the individual queries anf and the positional information pi are incorporated in the calculation. In accordance with the invention, depending on the determined speed of displacement kv of the terminal E concerned the frequency of further queries anf to the mobile terminal E concerned is controlled. This means that at a high speed of displacement kv of the mobile terminal E concerned queries anf to the mobile terminal E are initialized more frequently—i.e. at shorter intervals t′—than at a lower speed of displacement of the mobile terminal E concerned. It is assumed for the purposes of the exemplary embodiment that the mobile terminal E concerned has a low speed of displacement kv and therefore the intervals t′ of the subsequent queries anf are larger compared to the initial intervals t—indicated in FIG. 2 by the abbreviation t′<t. Since the speed of displacement kv of the terminal E concerned can be determined again following each query anf the frequency of the queries anf can be adjusted continuously.
[0021] In an alternative embodiment of the invention (not shown) the position P 1 . . . Pn of the terminal E concerned is not determined directly in the terminals E, but instead the radio signal level measurements already described above are performed and the measured levels are transmitted to the platform PF as measured information mi—indicated in FIG. 2 by the abbreviation mi. In the platform both the position P 1 . . . Pn and the speed of displacement kv of the terminals E concerned are determined/calculated using the transmitted levels, with a distance to the particular radio transmitter being determined from the measured level.
[0022] Controlling the frequency of the queries anf is advantageous since particularly at a low speed of displacement kv of the mobile terminals E concerned the frequency of the queries anf can be reduced to a minimum and the communication exchange between the mobile terminals E concerned and the platform PF is thereby significantly reduced. Thus the mobile terminals E and the platform PF are relieved of a considerable dynamic load and consequently the mostly scarce resources in the mobile terminals E and in the platform PF can be used more effectively and/or the resources that become free are available for other uses/applications AP.
[0023] The inventive methods are not limited to the exemplary embodiment, but can be employed in all systems in which the recording of the position of the terminals is to be updated in order to influence/control further actions using this updated position as part of applications or functions. | The geographical position, or measured information from which the geographical position may be deduced, of a mobile terminal is determined via requests to the terminal and positional information or measured information transmitted to a control device. The speed of displacement of the mobile terminal is determined from the transmitted positional information or measured information and the frequency of requests controlled depending on the determined speed of displacement of the mobile terminal. The communication exchange, in particular, for mobile terminals with low speeds of displacement is therefore significantly reduced and the mobile terminals and central devices provided with dynamic load reduction. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable.
BACKGROUND OF THE INVENTION
The present invention relates in general to blood circulatory assist devices, and, more specifically, to autonomous control of a pump to maintain optimum blood flow under a variety of conditions including partial obstructions and low blood volume.
Many types of circulatory assist devices are available to either short term or long term support for patients having cardiovascular disease. For example, a heart pump system known as a left ventricular assist device (LVAD) can provide long term patient support with an implantable pump associated with an externally-worn pump control unit and batteries. The LVAD improves circulation throughout the body by assisting the left side of the heart in pumping blood. One such system is the DuraHeart® LVAS system made by Terumo Heart, Inc., of Ann Arbor, Mich. One embodiment of the DuraHeart® system may employ a centrifugal pump with a magnetically levitated impeller to pump blood from the left ventricle to the aorta. An electric motor magnetically coupled to the impeller is driven at a speed appropriate to obtain the desired blood flow through the pump.
A typical cardiac assist system includes a pumping unit, electrical motor (e.g., a brushless DC motor integrated into the pump), drive electronics, microprocessor control unit, and an energy source such as rechargeable batteries. The system may be implantable, either fully or partially. The goal of the control unit is to autonomously control the pump performance to satisfy the physiologic needs of the patient while maintaining safe and reliable system operation. A control system for varying pump speed to achieve a target blood flow based on physiologic conditions is shown in U.S. Pat. No. 7,160,243, issued Jan. 9, 2007, which is incorporated herein by reference in its entirety. Thus, a target blood flow rate may be established based on the patient's heart rate so that the physiologic demand is met. The control unit may establish a speed setpoint for the pump motor to achieve the target flow. Whether the control unit controls the speed setpoint in order to achieve flow on demand or whether a pump speed is merely controlled to achieve a static flow or speed as determined separately by a physician, it is essential to automatically monitor pump performance to ensure that life support functions are maintained.
The actual blood flow being delivered to the patient by the assist device can be monitored either directly by sensors or indirectly by inferring flow based on motor current and speed. Despite the attempt by the control unit to maintain a target flow, various conditions such as obstructions of the inflow conduit or outflow conduit from the pump, low blood volume due to dehydrations, or other problems may cause the blood flow to decrease. Low flow and no flow alarms are conventionally employed to indicate conditions when the blood flow through the pump has inadvertently fallen below a low flow threshold or a no flow threshold, respectively. The alarms may comprise warning sounds, lights, or messages to allow the patient or caregiver to take corrective action. In order to provide a greater safety margin, it would be desirable to identify and correct flow problems before the low flow or no flow thresholds are reached.
SUMMARY OF THE INVENTION
In one aspect of the invention, a method is provided for controlling a pump motor in an assist device for pumping blood of a patient. An actual pump flow value of the pump motor is monitored during pumping of the blood by the assist device. An expected minimum pump flow value is determined corresponding to nominal pump operation for the monitored speed and current flow. When the actual pump flow value is greater than the expected minimum pump flow value, a target speed of the pump motor is set according to predetermined criteria (which may comprise a predefined setpoint as determined by a physician, for example). When the actual pump flow value is less than the expected minimum pump flow value for at least a first diagnostic wait time, a pump flow diagnostic state is entered.
In an embodiment, the pump flow diagnostic state comprises entering a low pump flow state if the actual pump flow value is less than a low flow threshold for at least a low flow wait time. The low flow threshold is less than the expected minimum pump flow value, and the low pump flow state includes generating a low flow warning. A no pump flow state is entered if the actual pump flow value is less than a no flow threshold for at least a no flow wait time. The no pump flow state includes generating a no flow warning, wherein the no flow threshold is less than the low flow threshold, and wherein the no flow wait time is less than the low flow wait time. An obstructed flow diagnostic state is entered if the actual pump flow value is less than the expected minimum pump flow value for at least an obstruction diagnostic wait time, wherein the obstruction diagnostic wait time is greater than the low flow wait time.
In an embodiment, the obstructed flow diagnostic state comprises selectably modifying the target speed of the pump motor and monitoring the resultant actual pump flow value. An inflow obstruction is detected if a reduction in target speed is correlated with a predetermined increase in the resultant actual pump flow value. If an inflow obstruction is detected, then the target speed is selectably decreased to a new target that substantially maximizes the actual pump flow value.
In an embodiment, the obstructed flow diagnostic state comprises detecting an outflow obstruction if a reduction in target speed is correlated with a predetermined decrease in the resultant actual pump flow value. If an outflow obstruction is detected, then the target speed is selectably increased to a new target until either a predetermined maximum speed or an actual pump flow value substantially equal to the expected minimum pump flow value is obtained.
In an embodiment, changes in pulsatility associated with the modified speed of the pump motor are also used to detect an inflow or outflow obstruction.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a circulatory assist system of a type employing the present invention.
FIG. 2 is a graph showing changes in volumetric flow occurring during operation of a circulatory assist system.
FIG. 3 is a flowchart showing one preferred method of the invention.
FIG. 4 is a graph illustrating certain changes in flow and pulsatility that may be associated with changes in pump speed under certain conditions.
FIGS. 5 and 6 are graphs showing large and small flow increases that may be associated with a reduction in pump speed.
FIG. 7 is a matrix showing general correlations of pump speed, flow, and pulsatility with inflow and outflow obstructions.
FIG. 8 is a more detailed decision matrix for one preferred embodiment.
FIG. 9 is a graph showing pump speed adjustments and resultant changes in flow when correcting for a detected obstruction.
FIG. 10 is a flowchart showing a further method of the invention.
FIG. 11 is a state diagram corresponding to another preferred embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1 , a patient 10 is shown in fragmentary front elevational view. Surgically implanted into the patient's abdominal cavity 11 is the pumping portion 12 of a ventricular assist device. An inflow conduit 13 conveys blood from the patient's left ventricle into the pumping portion 12 , and an outflow conduit 14 conveys blood from the pumping portion 12 to the patient's ascending thoracic aorta. A power cable 15 extends from the pumping portion 12 outwardly of the patient's body via an incision to a compact controller 16 . A power source, such as a battery pack worn on a belt about the patient's waist, and generally referenced with the numeral 17 , is connected with controller 16 .
Each of the conduits 13 and 14 may include a tubular metallic housing proximate the pumping portion 12 which may connect to elongated segments extending to the heart and ascending aorta, respectively. At the end of inflow conduit 13 connected to the patient's heart (preferably at the apex of the left ventricle), and at the end of outflow conduit 14 connected to the ascending thoracic aorta, the conduits are generally attached to the natural tissue by sutures through the use of a sewing ring or cuff so that blood flow communication is established and maintained. The distal end of the inflow conduit 13 is inserted through the ventricle wall and into the heart in order to establish blood flow from the heart to the pumping portion 12 .
FIG. 2 illustrates a target flow Q Target at 20 and an actual flow value 25 that varies over time. A no flow threshold 21 and a low flow threshold 22 define no flow region 23 and low flow region 24 , respectively, wherein appropriate alarms are generated by a pump control unit whenever actual flow dips into these regions. The trajectory of actual pump flow value 25 may fall to a value below an expected minimum flow threshold 26 into a respective diagnostic region 27 . Expected minimum flow threshold 26 may be obtained from a lookup table or a model based on empirically derived flow profiles that result from various inflow or outflow obstructions or various reductions in blood volume. The present invention is configured to detect operation in region 27 and to take steps to identify a potential cause and a remedy in order to increase flow if possible.
When the actual flow falls below an expected minimum flow that should be present in view of the operating speed of the pump (i.e., assuming no obstructions and proper blood volume), the present invention enters a diagnostic state for identifying a potential cause of the impaired flow such as a partial or complete obstruction of the inflow conduit or the outflow conduit, or a condition wherein a flow is saturated for a given pump speed due to a limited blood volume resulting from dehydration, etc.
As shown in FIG. 3 , a method of the invention begins in step 30 wherein a physician or other medical practitioner configures target values and performance limits pertaining to blood flow rate and pump speed to be provided for a particular patient. The circulatory assist device then monitors for physiological conditions such as heart rate or pump pulse rate in step 31 . In step 32 , a target flow rate and a target speed (i.e., setpoint speed) are determined and used for controlling the system as known in the art. Alternatively, a speed setpoint may be determined according to other predetermined criteria such as a setpoint configured according to a static value chosen by a physician for the particular patient. A check is performed in step 33 to determine whether the actual (i.e., indirectly estimated) pump flow value (eLPM pump ) is less than an expected minimum pump flow value (LPM ExpMin ) for greater than a diagnostic wait time (T FlowDiagWait ). As mentioned above, eLPM pump is an estimated average pump flow for a given pump speed. If not, then a return is made to step 31 and pump operation continues normally with the pump speed being determined by a target flow that is set according to physiological conditions.
If the actual pump flow value is less than the expected minimum flow value in step 33 , then a check is made in step 34 to determine whether the actual flow is less than a low flow threshold (LPM LowFlow ). In particular, step 34 preferably requires that the actual flow value be less than LPM LowFlow for greater than a predetermined low flow wait time (T LowFlowWait ). When eLPM pump <LPM LowFlow then a low flow warning is generated in step 35 . A low flow state is then entered while the low flow warning continues. Checks are made in step 36 to determine whether the actual flow value has risen above the low flow threshold for greater than the low flow wait time, and a check is made in step 37 to determine whether the actual flow value is less than a no flow threshold (LPM NoFlow ) for at least a no flow wait time (T NoFlowWait ). The value of T NoFlowWait is less than the value of T LowFlowWait so that detection of a no flow condition has priority. If the actual flow value rises above the low flow threshold, then the warning is turned off in step 38 and a return is made to step 34 . If an actual flow value falls below the no flow threshold for the no flow diagnostic wait time, then a no flow warning is generated in step 40 to indicate that a greater urgency of taking corrective action. While in a no flow warning state, a check is made in step 41 to determine whether the actual flow value rises above the no flow threshold for longer than the no flow wait time. When it does, the no flow warning is turned off in step 42 , the low flow warning is turned off in step 38 , and a return is made to step 34 .
When step 34 determines that the actual flow value has not stayed below the low flow threshold for the low flow diagnostic wait time, then a check is made in step 43 to determine whether the actual flow value stays below the expected minimum flow value for at least an obstruction diagnostic wait time (T ObsDiagWait ) which is longer than both the low flow diagnostic wait time and the no flow diagnostic wait time. If not, then a check is made in step 44 to determine the actual flow value has recovered above the expected minimum flow value for at least the diagnostic wait time (T FlowDiagWait ), and if so, then a return is made to step 31 for nominal pump control. If the condition is not true in step 44 , then a return is made to step 34 for continuing to monitor for either a low flow condition or an obstructed condition. When the condition in step 43 is satisfied then the method proceeds to step 45 wherein a potential obstruction is diagnosed as described below.
The present invention is based in part on an observation that a nominal reduction in pump speed generally results in an increase in flow if an inflow obstructions exists. As shown in FIG. 4 , a pump is operating at a first speed at 50 , but then a speed reduction 51 to a lower speed 52 is deliberately introduced. After a sufficient time to allow flow to stabilize at a new value for measurement, speed then increases at 53 back to the original speed at 54 . An actual pump flow Q has an original value at 55 will rise to a higher flow at 56 during a reduced pump speed at 52 in the event that an inflow obstruction exists. If an outflow obstruction exists, then the actual flow instead decreases as shown at 57 during the time of reduced pump speed 52 .
The change in pump speed may also affect the pulsatility index (e.g., the difference between the maximum and minimum flows divided by the average maximum flow) such that an initial pulsatility at 60 decreases to a value at 61 in the presence of an inflow obstruction when pump speed is reduced at 52 . On the other hand, in the presence of an outflow obstruction the pulsatility will increase at 62 during the speed reduction. Inspection of the change in flow resulting from a deliberate speed reduction may be sufficient to differentiate between an inflow obstruction and an outflow obstruction, but it may be coupled with an inspection of the change in pulsatility to potentially improve an identification.
The diagnostic relationships employed by the present invention are shown in greater detail in FIGS. 5 and 6 . FIG. 5 shows an inflow obstruction wherein a pump speed RPM setpoint and a pump flow eLPM pump are measured at a first time t 1 . Pump speed is reduced by a predetermined speed of RPM ObsDiag at a time t 2 . At time t 2 , the actual pump flow has stabilized at a new value representing an increase by more than a threshold designated LPM ObsDiag , which indicates the presence of the inflow obstruction. In a preferred embodiment, a plurality of speed modification trials of the type shown in FIG. 5 are repeated in order to gather statistics for increasing a confidence level in detecting the inflow obstruction.
In FIG. 6 , the actual flow through the pump increases during the speed reduction by an incremental flow that is less than the value of LPM ObsDiag . In a preferred embodiment, the present invention does not detect an inflow obstruction based on only the smaller increase in pump flow, but may require simultaneous change in pulsatility index in order to decide on the presence or absence of an inflow obstruction.
More specifically, an inflow or outflow obstruction may be determined as shown in FIG. 7 . When pump speed is reduced and the resultant pump flow increases while pulsatility index decreases, then an inflow obstruction is detected. On the other hand, when the speed reduction creates a decreased resultant flow together with an increased pulsatility index, then an outflow obstruction is detected.
The present invention may also distinguish between different levels of confidence in judging the presence of inflow and outflow obstructions for a saturated flow condition. For example, a large jump in flow being produced by a reduction in pump speed may always generate an indication of an inflow obstruction. Depending on whether pulsatility experiences a large drop or a small drop, the confidence of the inflow obstruction may be characterized as either probable or possible, respectively. As further shown in FIG. 8 , a small jump in flow may correlate with a likely inflow obstruction if the pulsatility also experienced a large drop. If both the jump in pump flow and the drop in pulsatility are small (i.e., less than respective thresholds), then the diagnostic decision may correspond to a “no call” with respect to whether there is any obstruction or a saturated flow.
When a reduced speed generates neither a large change in flow nor a large change in pulsatility, then a saturated flow may be detected. In the presence of a saturated flow, it may be desirable to reduce pump speed to the lowest value that maintains the current flow value.
An outflow obstruction may be detected according to FIG. 8 when a large drop in the flow is correlated with the reduction in pump speed. If the large drop in flow occurs with a large jump in pulsatility, then an outflow obstruction is probable. If associated with a small jump in pulsatility, then an outflow obstruction is classified as possible. When a small drop in pump flow occurs with a large jump in pulsatility, then an outflow obstruction is classified as likely, but if coupled with a small jump in pulsatility then no call is made.
Based on the confidence with which either an inflow or an outflow obstruction is detected, corresponding measures can be taken to attempt to provide a greater flow or even restore the flow at least the expected minimum flow. As shown in FIG. 9 , a plurality of speed modification trials including trials 65 and 66 are performed in order to assess the most likely obstruction. Prior to the corrective action, the pump speed has a setpoint 67 and a corresponding flow value 68 . When an inflow obstruction is present, corrective action comprises gradually decreasing the pump speed at 70 to produce a gradual increase in flow at 71 . A predetermined minimum speed 72 may preferably have been established by the physician based on the physiology of the patient, and if the speed reaches that minimum then no further changes would be made. As long as further decreases in speed along line 70 generate a corresponding increase in pump flow along 71 , then the speed continues to decrease. When the resultant flow reaches a peak at 73 and then decreases at 74 , the reduction in pump speed ceases at 75 . Then the speed achieving the highest flow is adopted at 76 .
In the case of a detected outflow obstruction, corrective action comprises increasing the pump speed at 80 which results in an increased pump flow at 81 . The increase may continue until either reaching a maximum pump speed 82 as previously determined by a physician or until pump flow reaches the expected minimum flow.
The plurality of trials and the corrective actions are further described in the method of FIG. 10 . In step 85 , an actual flow value and a pulsatility index are measured at the current speed setpoint. In step 86 , the pump speed is reduced by a preset amount. In step 87 , a new flow value and pulsatility index are measured at the reduced speed. A check is made in step 88 to determine whether a predetermined number of trials have been obtained. If not, speed is increased back to the original setpoint in step 89 and a return is made to step 85 .
Once sufficient trials have been conducted, the trials are classified in step 90 . Classification of each trial is performed in accordance with FIG. 8 , for example. The classified trials are then examined statistically in order to ensure that sufficient data is present to indicate either an inflow obstruction, outflow obstruction, or saturated flow. In a preferred embodiment, a majority of trials must indicate a respective condition. In step 91 , a check is made to determine whether a majority of trials indicate that an inflow obstruction is either likely, possible, or probable. If so, then corrective action to increase pump flow begins at step 92 by dropping the pump speed by a predetermined amount. A check is performed in step 93 to determine whether the speed has been reduced to a predetermined minimum speed. If not, then a check is performed in step 94 to determine whether the latest drop in speed has instead caused a flow decrease. If not, then a return is made to step 92 to drop the speed once again. If a minimum speed is reached in step 93 , then the minimum speed is set as a new speed setpoint and the method returns to point A in FIG. 3 . In FIG. 3 , the method waits during a predetermined wait time (T EndDiagWait ) in step 110 before returning to normal operation. This periodic return to normal operation ensures that nominal operation is utilized whenever possible.
Returning to FIG. 10 , in the event that a flow decrease is detected in step 94 then the speed setpoint is set to the last speed that obtained a flow increase in step 96 and a return is made to point A.
If there are not a majority of trials detecting an inflow obstruction in step 91 , then a check is made in step 97 to determine whether a majority of trials indicate a saturated flow. If they do, then pump speed is dropped by a predetermined amount in step 98 . A check is performed in step 99 to determine whether a minimum speed has been reached. If not, then a check is made in step 100 to determine whether a predetermined flow decrease has occurred (i.e., whether the flow has become unsaturated). If not, then a return is made to step 98 to drop speed once again. If a minimum speed is reached in step 99 , then the minimum speed is adopted as a new speed setpoint and the method returns to point A. If a flow decrease is detected in step 100 , then the current speed is used as a new speed setpoint and a return is made to point A.
If a majority of trials do not indicate a saturated flow condition in step 97 , then a check is made in step 103 to determine whether a majority of trials indicated that an outflow obstruction is likely, possible, or probable. If not, then the flow problem has not been properly diagnosed and the method may retry to diagnose the obstruction in step 104 (e.g., by repeating a new plurality of trials at step 85 ). If a majority of trials indicate an outflow obstruction, then pump speed is increased by a set amount in step 105 . A check is made in step 106 to determine whether a maximum speed has been reached. If not, then a check is made in step 107 to determine whether the result flow has reached the expected minimum flow value. If not, then a return is made to step 105 to further increase the speed. If a maximum speed is detected in step 106 , then the maximum speed is adopted as a new speed setpoint in step 108 and a return is made to point A. If the flow reaches the expected minimum flow value in step 107 , then the current speed is used as a new speed setpoint in step 109 and a return is made to point A.
The present invention can also be understood using a state diagram as shown in FIG. 11 . State 115 is a normal pump control state wherein pump control may be implemented as according to U.S. Pat. No. 7,160,243, for example. As long as an actual flow remains greater than the expected minimum flow, operation continues to remain in state 115 . When pump flow falls below the expected minimum flow for greater than time T FlowDiagWait , then a transition is made from state 115 to a flow diagnostic state 116 . A transition is made back from state 116 to state 115 when the flow value remains above the expected minimum flow for greater than T FlowDiagWait . State 116 also checks for low flow. Thus, if actual flow falls below the low flow threshold for greater than a time T LowFlow then a transition is made to a low flow alarm state 117 . A transition would be made back from state 117 to 116 whenever the actual flow remains greater than the low flow threshold for greater than T LowFlow . State 117 monitors for a no flow condition by comparing actual flow with a no flow threshold. If actual flow is less than the no flow threshold for at least time T NoFlow then a transition is made to a no flow alarm state 118 . Flow continues to be compared with the no flow threshold and if it remains above the no flow threshold for at least T NoFlow then a transition is made back to flow diagnostic state 116 .
While in state 116 , actual flow continues to be compared to the expected minimum flow value and if it remains below it for greater than a time T ObsDiagWait , then a transition is made to diagnose obstruction state 120 . While in state 120 , a plurality of trials are conducted by modifying the pump speed in order to attempt to classify either an inflow obstruction, outflow obstruction, or saturated flow condition. When an inflow obstruction is detected, a transition is made to state 121 for executing a speed reduction action. When an outflow obstruction is detected, then a transition is made to state 123 for executing a speed increase action. When a saturated flow condition is detected, a transition is made to state 122 for executing a speed reduction action. After the actions in states 121 - 123 , transitions are made to wait state 124 wherein the pump continues to operate at a new speed setpoint, thus achieving the best flow results obtainable under current conditions. After a wait time (T EndDiagWait ) corresponding to an expected time in which conditions may eventually change, a transition is made back to normal pump control state 115 with a possible reintroduction of corrective speed changes if flow again does not exceed the expected minimum flow. | A circulatory assist system has a pump with a motor coupled to rotate the pump at a selectable speed. A controller drives the motor at a target speed and collects blood flow measurements during operation of the pump. An impaired flow condition is identified when a plurality of successive blood flow measurements are between an expected minimum flow and a low flow threshold, such that the low flow would necessitate issuing an alert. During the impaired flow condition, it is detected whether an inflow obstruction exists by determining whether a reduction in speed of the pump is correlated with a predetermined increase in the blood flow measurements. If the inflow obstruction is detected, then the speed of the pump is further reduced to further increase the blood flow measurements. | 0 |
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