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CONTRACTUAL ORIGIN OF THE INVENTION
The United States Government has rights in this invention pursuant to Contract No. W-31-109-ENG-38 between the U.S. Department of Energy and the University of Chicago.
FIELD OF THE INVENTION
This invention relates to a method and apparatus for detecting and measuring the behavior and characteristics of magnetic materials with very high resolution and accuracy.
BACKGROUND OF THE INVENTION
Magnetic materials are key components in a large number of technologies and devices such as car starters and alternators, microwave bandpass filters, and insertion devices for synchrotron radiation sources. Permanent magnets are an important class of magnetic materials and are defined as materials that retain a high degree of magnetization after a magnetizing field is removed. The amount of magnetic energy stored per the material's unit volume has increased ten-fold in the past few years due to technological progress in the synthesis of modern permanent magnets which feature rare-earth atomic constituents. This has allowed miniaturization of permanent magnets and increased versatility in their use. The resulting complex artificial structures, however, feature not only more than one type of magnetic atom, but atoms of the same species in different atomic environments. The simultaneous presence of rare-earth constituents in dissimilar crystal sites, or atomic environments, hinders our ability to understand their individual magnetic contributions by means of current detection methods. Not being able to fully understand existing materials inhibits the ability to develop new generations of permanent magnetic materials with improved performance in areas such as magnetic hardness (stability against demagnetizing fields) which are dictated by the interaction of magnetic moments with the local crystalline environment. Previous attempts to understand these properties have used established techniques such as Mossbauer spectroscopy and neutron diffraction. More recently, x-ray magnetic circular dichroism has also been used to detect and measure these and other characteristics of magnetic materials.
The main limitation of the neutron diffraction technique is that it probes all magnetic elements simultaneously. In the case of modern high-strength magnets, the majority of the magnetic atoms in the structure are transition metal atoms, such as Iron, while only a minority are rare-earth type. The magnetic hardness, however, is dominated by the minority rare-earth atoms. Understanding and improving magnetic hardness requires accurate detection of magnetic signals from these rare-earth atoms only. This is not possible using neutron diffraction. Finally, x-ray magnetic circular dichroism can separate magnetic contributions by element type, but cannot separate contributions from the same element in nonequivalent crystal sites or atomic environments. Only in special circumstances, where absorption thresholds between atoms in nonequivalent sites are large enough (vary rare), can this technique yield the information needed. In summary, none of the methods briefly discussed above, even when taken together, have been able to provide a complete understanding of the way in which modern permanent magnetic materials function and behave.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved method and apparatus for detecting and measuring the behavior and characteristics of magnetic materials.
It is another object of the present invention to provide for the use of x-ray magnetic circular dichroism to measure magnetic signals from different magnetic elements in a material, and magnetic signals of like elements present in nonequivalent crystal sites or atomic environments of a magnetic material.
A further object of the present invention is to determine the magnetic characteristics of individual atoms in permanent magnetic materials as determined by the interaction of the atom's magnetic moment with its local crystalline environment.
The present invention provides a way to directly detect and measure the magnetic signals from elements of the same species in nonequivalent atomic environments, i.e., to separate magnetic signals not only by element type, but also by the type of environment. This inventive x-ray detection and analysis technique uses circularly polarized x-rays to study magnetism in crystals with unprecedented resolution power. The technique combines x-ray diffraction from crystals with the elemental magnetic fingerprints obtained near x-ray absorption edges to yield element and site-specific magnetic data. Specifically; this invention functions by combining knowledge from crystallography and by manipulating the polarization of x-rays, the energy of which is tuned near element-specific electronic excitations. Site separation is achieved by the proper choice of diffraction conditions and magnetic sensitivity is obtained by measuring the contrast in diffracted intensity for opposite helicities of circularly polarized x-rays. Proof of principle studies have been carried out on Nd 2 Fe 14 B (the best permanent magnet composition presently available) with good success.
This invention is directed to apparatus for determining the magnetic characteristics of a magnetic material, the apparatus comprising: a phase retarder for converting a linearly polarized incident x-ray beam to a circularly polarized x-ray beam which alternates between left-handed (LH) and right-handed (RH) helicity at a given frequency and has energy selected to interact with a designated species of atoms in the magnetic material; a first detector that measures the intensity of the circularly polarized x-rays incident on the magnetic material, wherein the incident photons are diffracted by atoms located at selected sites in the magnetic material to provide diffracted photons; a second detector for detecting the diffracted photons; and a counter coupled to the first and second detectors for counting and comparing the number of incident and diffracted photons for each left- and right-helicity, and providing an output signal representing the magnetic characteristics of a designated species of atoms at selected sites in the magnetic material.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended claims set forth those novel features which characterize the invention. However, the invention itself, as well as further objects and advantages thereof, will best be understood by reference to the following detailed description of a preferred embodiment taken in conjunction with the accompanying drawings, where like reference characteristics identify like elements throughout the various figures, in which:
FIG. 1 is a simplified schematic diagram of a digital lock-in detection system for detecting and measuring the dichroic diffraction of circularly polarized x-rays in magnetic materials in accordance with the present invention; and
FIG. 2 is a graphic comparison of the detection of circularly polarized x-rays dichroically diffracted from magnetic materials in the prior art with the detection provided by the digital lock-in detection system of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The ability of x-ray-based techniques to separate magnetic contributions from different elements in heterogeneous samples is one of the most important advantages of x-rays over neutrons when probing magnetism. X-ray magnetic circular dichroism (XMCD) achieves this separation by tuning the x-ray energy to element-specific electron excitations whose absorption cross section depends on x-ray helicity (left or right). This dichroism arises from an imbalance between the spin-up and spin-down density of electronic states near the Fermi energy, which is characteristic of ferro (ferri) magnetic materials. While x-ray dichroism is commonly measured in absorption, a related dichroic effect occurs in the resonant scattering/diffraction of circularly polarized x-rays, where the virtual photoelectron is sensitive to that same spin imbalance in the intermediate state. Analog lock-in detection of XMCD in the absorption channel is already available at the X-ray Operations and Research Sector 4 of the Advanced Photon Source at Argonne National Laboratory, Argonne, Ill. Now, a digital lock-in detection scheme in accordance with the present invention has been developed for measurements of dichroic scattering/diffraction.
Advantages of dichroic scattering/diffraction include the ability to exploit structural factor effects in crystals in order to separate magnetic contributions from elements of the same species in nonequivalent crystal sites, to determine element-specific magnetization depth profiles in films and multilayers, and to separate magnetic signals from the same element in dissimilar crystal phases in multiphase materials such as nanocomposites.
The inventive detection system shown in FIG. 1 permits measurement of the x-ray-diffracted intensity to be synchronized with the helicity modulation of a circularly polarized incoming x-ray beam, which alternates in the 1- to 50-Hz range. A square wave with half-duty cycle expands/contracts a piezoelectric actuator causing a phase-retarding optical element to yield opposite helicities of circular polarized x-rays. Upon helicity switching, a timing module triggers incident and scattered intensity scalers of a dual photon counter for a time interval (gating) just below the half period of the square wave. This allows measurement of incident and scattered x-ray beam intensities for opposite helicites to be performed over many helicity switchings in a short time, with the data for each type of helicity stored in even and odd addresses, respectively, of the photon counter's memory arrays. This detection scheme, coupled to a fast-counting avalanche photodiode detector, yields large improvements in signal-to-noise ratios and a reduction of systematic errors over conventional detection approaches, wherein beam helicity is switched only once.
FIG. 2 compares data collected by using a conventional method (top) to that collected by using digital lock-in over 20 cycles of helicity switching in accordance with the present invention. In addition to improvements in data quality, the lock-in measurement was done in half the time of the conventional measurement. This development extends the detectability of dichroic scattering/diffraction to 1 part in 10,000. This level of sensitivity is particularly suited for detection of dichroic diffraction from single crystals and small-angle dichroic reflectivity/scattering from layered nanostructures.
Referring to FIG. 1 , there is shown a simplified schematic diagram of a digital lock-in detection system 10 for detecting and measuring the magnetic characteristics of a magnetic material in accordance of the principles with the present invention. The digital lock-in detection system 10 includes a phase retarder comprised of the combination of a piezoelectric actuator 14 and a phase retarding optical element 15 through which an incident linearly polarized x-ray beam 12 is directed. A timing module 42 provides a square wave input to the piezoelectric actuator 14 for modulating the phase retarding optical element 15 , with the square wave input alternating in the 1- to 50-Hz range. The square wave input signal with a half-duty cycle expands and contracts the piezoelectric actuator 15 causing the phase retarding optical element 15 to provide a circularly polarized x-ray beam output having opposite helicities of the circularly polarized x-rays. The opposite helicities of the circularly polarized x-rays are provided to an ionization chamber 16 which includes an ionizing gas across which a high voltage is applied. The incident photons knock off electrons from the gas atoms, with the number of electrons collected being proportional to the number of photons. Ionization chamber 16 thus provides for the detection of the number of photons transmitted through the phase retarding optical element 15 which is a measure of the intensity of the incident circularly polarized x-ray beam 12 . The phase retarding optical element 15 is preferably a single crystal diamond capable of changing the helicity of the circular polarized incident x-ray beam 12 .
A voltage generated in the ionization chamber 16 in response to the dual helicity x-ray beam is directed to a voltage-to-frequency converter 24 , while the x-ray beam is directed onto a magnetic sample 18 . Disposed adjacent the magnetic sample 18 is an electromagnet 20 for aligning the magnetization of the magnetic sample along a predetermined direction established as a reference by the magnetic field of the electromagnet 20 . An avalanche photodiode detector 22 outputs a voltage pulse to a constant fraction discriminator 26 , where the voltage pulses are converted to logic pulses at a frequency corresponding to the rate at which photons are scattered by the magnetic sample 18 and collected by the avalanche photodiode detector 22 . The output of the ionization chamber 16 to the voltage-to-frequency converter 24 is also a voltage and a measure of the number of photons with dual-helicity incident upon the magnetic sample 18 . The frequency signals from voltage converter 24 and constant fraction discriminator 26 are provided to a display device 28 in order to provide a visual comparison of the signal output by the ionization chamber 16 and the avalanche photodiode 22 .
The outputs from voltage converter 24 and constant fraction discriminator 26 are also respectively provided to an incident beam intensity scaler 44 and a scattered beam intensity scaler 46 of a dual photon counter 36 . The incident beam intensity scaler 44 and the scattered beam intensity scaler 46 open and close in a synchronized manner with the modulation in x-ray beam helicity. As such, they operate as filters to reject signals which do not have the same frequency as the input signal to the piezoelectric actuator 14 which modulates the phase retarding optical element 15 . The timing module 42 which provides the square wave input to the piezoelectric actuator 14 also provides a pulsed signal to a trigger circuit 38 within the dual photon counter 36 for insuring that the counter detects only signals at the operating frequency of the phase retarder. As shown in FIG. 1 , the half wave pulses output by the timing module 42 are synchronized with its trigger pulse output to the trigger circuit 38 . The dual photon counter 36 includes an RS 232 interface for communicating with a computer controller 48 responsive to control inputs such as from a system operator. The computer controller 48 might be in the form of a PC or a laptop computer.
Below the schematic diagram in FIG. 1 , there is shown a simplified schematic arrangement for the collection of helicity data for the incident and scattered beams. In row “A”, which is a representation of scaler 44 , plural spaced bins are provided for counting incident intensities of left (“L”) and right (“R”) helicity photons over time, such as over ten seconds. The lower row labeled “B”, which is a representation of scaler 46 , is used for counting scattered photons detected by the avalanche photodiode 22 for the same timing sequence (and hence helicity sequence) as in row “A” and the two are directly compared. The data stored in these scalers is read by the computer controller 48 via a RS 232 serial interface 40 .
Referring to FIG. 2 , there is shown a graphic comparison between measurements as made by a prior art approach and measurements made by the digital lock-in detection system 10 of the present invention. The upper graph shows conventional detection results using a scintillator detector. The lower graph shows detection using the digital lock-in detector system 10 of the present invention over 20 cycles of helicity switching using an avalanche photodiode as previously described. In addition to improvements in measured data quality as shown by comparing the upper and lower curves in FIG. 2 , the lock-in measurement in accordance with the present invention was done in half the time of the conventional measurement shown in the upper graph. This improvement extends the detectability of dichroic scattering/diffraction data to 1 part in 10,000. The digital lock-in detection system 10 of the present invention is particularly suited for detection of dichroic diffraction from single crystals and small angle dichroic reflectivity-scattering from layered nanostructures.
The present invention was used in the analysis of Nd 2 Fe 14 B, the best permanent magnet material currently available. Analysis of this magnetic material using the present invention showed that only one of the two dissimilar Nd sites is responsible for the magnetic stability of this material. Unexpectedly, the other site acts to reduce magnetic stability. Knowledge such as this is critical in designing future materials with specific desired magnetic properties. The present invention is also particularly adapted for the study of magnetic nanocomposites (i.e., mixtures of magnetically hard and soft materials at the nanoscale) as well as to the study of magnetic thin films. The present invention can also be used to measure magnetization depth profiles near interfaces between magnetic thin films, which are intimately related to the performance of thin film magnetic devices such as read heads in computer hard discs and spintronics devices such as magnetic random access memories.
While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the relevant arts that changes and modifications may be made without departing from the invention in its broader aspects. 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. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
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The polarization and diffraction characteristics of x-rays incident upon a magnetic material are manipulated to provide a desired magnetic sensitivity in the material. The contrast in diffracted intensity of opposite helicities of circularly polarized x-rays is measured to permit separation of magnetic signals by element type and by atomic environment. This allows for the direct probing of magnetic signals from elements of the same species in nonequivalent atomic environments to better understand the behavior and characteristics of permanent magnetic materials. By using known crystallographic information together with manipulation of the polarization of x-rays having energies tuned near element-specific electronic excitations and by detecting and comparing the incident and diffracted photons at the same frequency, more accurate magnetic measurements can be made over shorter observation periods.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11/016,940 entitled “System and Method for Termination of a Wire Rope” filed Dec. 2, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10/825,658 entitled “Method for Making a Termination for a Wire Rope for Mining Equipment” filed Apr. 14, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus and method for terminating a wire rope and connecting it to various pieces of equipment. In a preferred embodiment, the termination is used in association with a dump bucket or socket in the field of mining.
BACKGROUND OF THE INVENTION
[0003] This invention relates to clamping devices for cables and particularly to an improved open wedge socket for clamping the cable and facilitating release of the cable from the socket.
[0004] Open wedge sockets are typically used with cranes or other hoisting machines. The socket is attached to the free end of a cable that is suspended from the crane. The socket provides means for coupling the free end of the cable to buckets or other apparatus which are then lifted or transported by the crane.
[0005] Conventional open wedge sockets include a wedge member and a socket for receiving the wedge member. A cable is captured in the socket by passing the free end of the cable through the socket, laying the wedge on the cable, and returning the free end of the cable over the wedge and back through the socket. The cable bearing wedge is then driven into the socket with sufficient force to trap the cable and wedge within the socket. Examples of these conventional open wedge sockets are shown in U.S. Pat. Nos. 1,355,004; 1,745,449; 2,217,042; 2,372,754; 2,482,231; 3,654,672; and 3,957,237.
[0006] A slightly different example of a conventional open wedge socket is shown in Great Britain Patent No. 2,080,389. In this example, there are two wedge sections, one stationary and integral with the socket and the other movable into the socket to grip a cord. The cord is laid in the socket over the stationary wedge section and the moveable section is forced into the socket. This socket has the same problems as the other conventional sockets discussed above.
[0007] It is often necessary to release the cable from the wedge socket. In the conventional wedge sockets, the wedge must be driven out of the socket and the free end of the cable must be pulled back into and through the socket. The free end of the socket frequently becomes kinked or frayed during normal use of the wedge socket. A slight kink or fray can effectively prevent a user from driving the wedge out of the socket. Further, the damaged free end will not pass back through the conventional socket. Heretofore, the only solution to this problem has been to cut the damaged cable to remove the frayed or kinked end.
[0008] An example of a known open wedge socket is shown in U.S. Pat. No. 4,602,891 to McBride. McBride provides an open wedge socket for a cable that includes a wedge having a peripheral surface for engaging the cable, a housing including an outwardly opening channel for receiving the wedging cable, and an interference member having a sliding fit on the housing to capture the wedge and the cable in the channel. However, the McBride invention allows for a whip-like backlash from the frayed end of the cable when the interference member is removed.
[0009] Removal of the captured cable and wedge from a conventional wedge socket can also be hampered by the buried nature of the wedge itself. Because of the weight that is repeatedly carried on the socket during lifting operations, the wedge is typically forced into the socket so tightly that it is necessary to remove the wedge with a sledgehammer. The wedge is generally contained or buried within the socket so that it is unreachable by the head of the sledgehammer. Heavy-duty punches or levers may be required to enable the sledgehammer to reach and strike a buried wedge.
[0010] Removal of the wedge and cable in the manner described above is a cumbersome, labor intensive, time-consuming exercise and many times results in destruction of the cable. In some cases hydraulic hammers are used to dislodge the cable. The hammers create flying chips of metal and can cause serious injury. In other cases, the stored energy in the loop of the wire rope over the wedge is tremendous. Release of this energy as the rope is removed can cause severe injury. In some cases, the removal of prior art commercial systems has resulted in death. Because of the time, labor and danger involved, the wedge and cable removal process associated with conventional wedge sockets is also very costly, resulting in extended periods of equipment downtime and inefficient use of personnel.
[0011] A need has existed for a wire rope termination made by a fast process resulting in a light-weight, heavy duty termination. A further need has existed for connecting wire rope terminations to mining and other equipment quickly and safely. A further need has existed for a method to create wire rope terminations which result in great strength. The present invention meets these needs.
[0012] The wire rope terminations of the present invention also relate to the field of exothermic metallic reactions known as thermite reactions.
[0013] Thermite reactions are highly exothermic reactions. During such reactions initially solid reactants undergo oxidation and reduction processes which liberate great heat from the reaction products. Such thermite reaction processes serve various useful purposes. Important applications of the thermite reaction process include the welding of metallic members and the cast forming of metal or ceramic parts. In such applications the thermite reaction is utilized to produce a superheated molten metal to cast a part or produce a weld metal for the welding and joining of the members.
[0014] Thermite reactions are generally described as reactions between metal oxides and metallic reducing agents. The metal oxides chosen for the reaction are those which have low heats of formation. The reducing agents chosen for the reaction are those which exhibit oxide species with high heats of formation. The difference in the heat of formation of the reaction product metal oxide and the reactant metal oxide is the heat produced in the reaction, and, as indicated, such reactions are highly exothermic. Thermite reactions of particular interest due to their extensive industrial usage are as follows:
Heat Evolved Thermite Reactions K cal (1) 3Fe 3 O 4 + 8A1 = 9Fe + 4Al 2 O 3 719 (2) 3FeO + 2Al = 3Fe + Al 2 O 3 187 (3) Fe 2 O 3 + 2Al = 2Fe + Al 2 O 3 181 (4) 3CuO + 2Al = 3Cu + Al 2 O 3 275 (5) 3Cu 2 O + 2Al = 6Cu + Al 2 O 3 260
[0015] In present commercial form the thermite reactions noted above all require local temperatures of approximately 1750° F. in order to be self-propagating (i.e., in order to ignite and continue the reaction to completion). For this reason, starting materials of lower ignition temperatures (about 850° F.) are placed in direct contact with the thermite reaction materials. Such starting materials may be conveniently ignited with a flint igniter, or other like sparking or ignition device. Upon ignition of the starting material, the starting material serves to ignite the higher temperature ignition point thermite reaction materials.
[0016] After the termite reaction is complete, liquid metal from the crucible passes into a chamber or mold where it is solidified for use.
[0017] A conventional thermite reaction is shown U.S. Pat. No. 4,881,677 to Amos. Amos shows a thermite reaction containment vessel on method of using it which includes a crucible in which the exothermic material is contained and which is connected at its lower end via tap hold to a well chamber in which parts are welded together.
[0018] Accordingly, it is one desired aspect of the invention to combine the products of the thermite reaction to create a wire rope termination to be used in combination with a novel connector mechanism to provide an extremely high connection strength along with a mining wire rope connector that is extremely safe and easy to use.
SUMMARY
[0019] The invention disclosed herein provides a drag socket comprising a frame, a first attachment means for connecting the frame to a control line, a second attachment means for connecting the frame to a drag line, a socket body removably attached to the frame, a releasing wedge releasably inserted into the socket body, a locking wedge releasably inserted into the releasing wedge, a wire rope termination fused to a wire rope adjacent the locking wedge, and a load plate movably attached to the frame adjacent the releasing wedge whereby the releasing wedge is retained in the socket body when a force is applied to the wire rope.
[0020] The invention also discloses a process of forming a drag socket attached to a wire rope comprising the steps of providing a drag socket frame, inserting the wire rope into a socket body in the drag socket frame, forming a termination on the wire rope, applying a releasing wedge to the wire rope and placing it into the socket body, applying a locking wedge to the wire rope and placing it into the releasing wedge, applying a load plate adjacent the socket body in a position to resist forces from the releasing wedge, and applying tension to the wire rope to move the termination to compress the locking wedge and the releasing wedge.
[0021] Additionally, the invention discloses a process of releasing a drag socket from a wire rope comprising the steps of providing a drag socket frame, providing a termination on the wire rope, providing a locking wedge adjacent the termination, providing a releasing wedge around the locking wedge, providing a socket body, secured in the socket frame around the releasing wedge, providing a load plate adjacent the releasing wedge and removably secured within the frame, providing a retaining means for applying pressure to the load plate and the frame, and removing the retaining means whereby pressure on the load plate is released and the releasing wedge is released.
[0022] The invention also discloses an apparatus for connecting a drag line to a drag chain comprising a drag line termination means, fused to the end of the drag line for rigidly expanding the diameter of the drag line, a connector frame attached to the drag chain and to a lift line, and a receiving means within the connector frame, abutting the drag line termination means, for compressing the drag line termination means to resist a force applied to the drag line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In the detailed description of the preferred embodiments presented below, reference is made to the accompanying drawings.
[0024] FIG. 1 depicts an exploded isometric view of the apparatus used in the method for making a termination for a wire rope using an exothermic metallic material.
[0025] FIG. 2 depicts an isometric view of the apparatus used in the method.
[0026] FIG. 3 depicts a front view of the assembled apparatus used in the method.
[0027] FIG. 4 depicts a cross-sectional side view of the assembled apparatus used in the method.
[0028] FIG. 5 depicts a perspective view of a socket usable with the termination.
[0029] FIG. 6 a is a cutaway plan view of an alternate embodiment of a socket usable with the termination.
[0030] FIG. 6 b depicts a side view of an alternate embodiment of a socket usable with the termination.
[0031] FIG. 7 depicts an isometric view of an alternate embodiment of a socket usable with the termination.
[0032] FIG. 8 a depicts a side view of two frustroconical wedges usable with the socket of the present invention.
[0033] FIG. 8 b depicts a plan view of three frustroconical wedges used with the termination of the present invention.
[0034] FIG. 9 a depicts an isometric assembly view of a wire rope, termination, several frustroconical wedges and a socket.
[0035] FIG. 9 b represents an isometric partially assembled assembly view of a wire rope, termination, several frustroconical wedges and a socket.
[0036] FIG. 9 c represents an isometric partially assembled view of a termination, socket and wire rope.
[0037] FIG. 10 shows an isometric view of an alternate embodiment of the invention.
[0038] FIG. 11 shows a section plane view of an alternate embodiment of the invention.
[0039] FIG. 12 shows a diagram of a mining system employing the connector systems of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that the embodiments can be practiced or carried out in various ways.
[0041] The termination described herein is made by a labor saving process for use with mining equipment. The termination for wire rope is lighter than conventional terminations used on drag lines in the mining industry, but has the same or greater strength.
[0042] The terminations for wire rope for the mining industry must be capable of sustaining a large break force. The termination of the present invention weighs appreciably less than similarly sized wire ropes with typical terminations, up to or exceeding 50% less. For example, a current style termination could weigh 6000 pounds for a 4⅜ inch diameter wire rope. In contrast certain embodiments of the invention utilize a termination weighing only about 1500-2800 pounds for the same diameter wire rope.
[0043] In the preferred embodiment, the terminations are for use with wire ropes with a diameter between ¼ inches and 7 inches. The terminations will work equally well with smaller and larger diameter wire rope. Typical wire ropes are made of steel, alloys of steel and combinations thereof. The wire rope can be a single strand rope or a multi-strand rope.
[0044] The terminations are made using the equipment of FIG. 1 . In a first embodiment, the termination 10 is formed on the end of a wire rope 15 using an exothermic metallic material. In an alternative embodiment, a liquid adhesive can be used to make the termination for the wire rope. The termination formed from the liquid adhesive has additional safety advantages as the termination can be made without heat in the field, preventing burns to workers, which is a much needed benefit.
[0045] For terminations made using the exothermic metallic material, one end of the wire rope is inserted into a mold 25 . FIG. 1 depicts the mold 25 as a two part mold with a top part 25 a and a bottom part 25 b , but a one piece mold can also be used. For large diameter wire ropes, a three piece mold may be used. In this embodiment, the top half of the mold is segmented along the axis of the wire rope opening 27 . For extremely large diameter ropes, a several piece mold may be used.
[0046] The pieces of mold 25 are held together with toggle-type latches (not shown) spaced around the periphery of the mold. In the preferred embodiment, using two pieces for the mold, there are four latches, two on each side. For the preferred embodiment where the mold is made in three pieces, six latches are used, two on each side and two on the top to hold the top two pieces of the top section of the mold together. The latches are placed so that leakage of molten metal between the seams of the pieces of the mold and down the access of the wire rope is minimized or preferably prevented.
[0047] The mold has a mold opening 35 . The mold opening can be rectangular, but an elliptical shape or round shape or other shape can be used. The opening should have a diameter that is adequate to permit molten metal to flow into the mold.
[0048] The mold has a cavity formed with two connected chambers, a wire rope opening 27 and a termination cavity 28 . Wire rope opening 27 is cylindrical and formed to the diameter of the wire rope. Termination cavity 28 in the preferred embodiment is also cylindrical having a diameter approximately two inches greater than the diameter of wire rope 15 . The dimensions of the termination cavity are a matter of design choice. In the preferred embodiment of a termination cavity for a 4½-inch diameter wire rope, the cavity is 7¾ inches in diameter and 4 inches long
[0049] The termination cavity can have a conical, cylindrical, or even rectangular shape. The cavity dictates the resultant shape of the termination. For example, the termination can include a hole perpendicular to the axis of the wire rope form or form a particular shape for connection to other equipment dependent on the shape of the termination cavity.
[0050] The external shape of the mold can be any functional shape but is preferably rectangular. The overall external dimensions of the mold of a preferred embodiment are between about 6 inches and about 20 inches; 10 inches is a preferred example. The width of the mold of a preferred embodiment can range from about 6 to about 16 inches; 8 inches is a preferred example. The length of a preferred embodiment can range from about 8 to about 24 inches; 12 inches is a preferred example.
[0051] The mold is preferably made of graphite or other materials that are very heat resistant. Another embodiment uses a sand casting mold as known in the art.
[0052] FIG. 2 shows an isometric view of wire rope 15 inserted into mold 25 . FIG. 2 also shows a crucible 45 , baffle 47 and baffle opening 51 .
[0053] FIG. 3 shows a front view of the crucible 45 with the mold 25 and a preferable circular opening for engaging the wire rope.
[0054] FIG. 4 depicts a cross-sectional view of the mold, crucible and wire rope.
[0055] The crucible provides a reaction chamber for the exothermic material. The crucible dimensions preferably coincide with or are slightly larger than the dimensions of the mold. The dimensions of the crucible of a preferred embodiment are between 10 and 18 inches in height (preferably 12 inches), between 10 and 20 inches in width (preferably 14.5 inches), and between 10 and 30 inches in length (preferably 15 inches). In the preferred embodiment, the walls of the crucible are one inch thick. The floor of the crucible is angled to assist the molten metal flowing out of the crucible through crucible opening 50 . The crucible can have a cylindrical shape, a rectangular shape, but generally it is hollow to receive material. The crucible opening has a shape that can be rectangular, ellipsoid, or another usable shape for flowing molten metal into the crucible. The crucible is preferably made of graphite or a heat resistant material that will not deform in the presence of high heat.
[0056] A separator 55 is disposed over the crucible opening 50 . The purpose of the separator is to keep the exothermic metallic material separate from the mold until ignition of the exothermic metallic material. Typically, separator 55 is a mild steel material; however, any sacrificial material can be used. In a preferred embodiment, the separator has a width between 2 inches and 6 inches in width and a length between 4 inches and 8 inches with a thickness that can range in a corresponding manner. In a preferred embodiment, the thickness of the separator is 10 gauge.
[0057] The terminations are made using an exothermic metallic material 40 that is placed into the crucible. The exothermic metallic material is preferably a powdered metallic material. Different sizes of granules, powder or small metal chips can be used in the same crucible. In the preferred embodiment, the material is provided in two phases. The first phase has a fine granularity to promote ease of ignition. The second phase has a coarse granularity to slow burning of the material and provide for adequate bulk to sustain the reaction. In the preferred embodiment, the first phase has granules of approximately 1/100 of an inch in diameter and the second phase granules have the size of approximately 1/10 an inch in diameter. In the preferred embodiment, the exothermic metallic material is sold under the trademark “Cad Weld”, available from ERICO, Inc. of Solom, Ohio.
[0058] The exothermic reactions utilized in the invention include but are not limited to the following:
Heat Evolved Thermite Reactions K cal (1) 3Fe 3 O 4 + 8Al = 9Fe + 4Al 2 O 3 719 (2) 3FeO + 2Al = 3Fe + Al 2 O 3 187 (3) Fe 2 O 3 + 2Al = 2Fe + Al 2 O 3 181 (4) 3CuO + 2Al = 3Cu + Al 2 O 3 275 (5) 3Cu 2 O + 2Al = 6Cu + Al 2 O 3 260
[0059] A baffle 47 is inserted over the crucible 45 to contain the heat and direct any resulting vapors out a baffle opening 51 . The baffle is preferably the same of similar shape to that of the crucible. The baffle is preferably made from steel plate. As shown in FIG. 4 , the baffle 47 has at least one internal baffle 61 for deflecting the heat and hot reaction gasses from the crucible.
[0060] In a preferred embodiment, the baffle can have a length ranging between 11 inches to 31 inches, a width ranging between 11 inches to 21 inches, and a height ranging between 11 inches to 19 inches in length. The preferred dimensions are 16 inches in length, 15 inches in width, and 18 inches in height. The preferred thickness of the baffle is 10 gauge.
[0061] The process of making a termination in the preferred embodiment begins by clamping the mold together by closing the appropriate toggle clamps. Crucible 45 and baffle 47 are then appropriately assembled. Assembly requires insertion of separator 55 in between crucible 45 and termination cavity 28 . Crucible 45 and mold 28 must be positioned so that ducted communication, through separator 55 is achieved.
[0062] In the preferred embodiment, the end of wire rope 20 is cleaned before the termination is formed. The cleaning step can be performed by any normal means of cleaning a substance. The preferred methods for cleaning are either by using a torch, by using chemicals to remove dirt, and combinations thereof.
[0063] After cleaning, wire rope 15 is inserted into wire rope opening 27 far enough to extend into termination cavity 28 . In the preferred embodiment of the method, the wire rope is extended approximately two thirds of the width of termination cavity 28 .
[0064] Exothermic metallic material 40 is then added to crucible 45 in at least one phase. When additional phases of exothermic metallic material 40 are desired in crucible 45 , the bulk phases are added first and allowed to settle. The fine phases are then added and allowed to settle.
[0065] The exothermic metallic material 40 is kindled in the crucible 45 . The exothermic metallic material 40 can be kindled using a striker, a torch, a flame, or other similar heat sources, and combinations thereof. Once kindled, the exothermic metallic material 40 burns quickly. The exothermic metallic material forms a ductile and malleable material and liquefies the separator 55 forming a molten material 60 .
[0066] Molten material 60 flows into mold 25 through mold opening 35 and comes into contact with end 20 of wire rope 15 . Molten material 60 is of such a temperature that is partially melts and fuses to the wire rope. Molten material 60 takes the form of mold 25 around end 20 forming termination 10 .
[0067] Molten material 60 is allowed to cool which in the preferred embodiment can take approximately 15 minutes. Crucible 45 and baffle 47 are then removed from mold 25 . Mold 25 is then separated into pieces by disconnecting the latches which hold the pieces of the mold together. If the mold is a single piece, it may need to be broken away from the termination. In cooling, exothermic material 60 slightly contracts, allowing the pieces of the mold to be removed easily.
[0068] The resultant termination 10 is lighter than conventional terminations and is typically capable of sustaining a higher break force than the wire rope.
[0069] A termination according to the present invention may be made using a liquid adhesive. If the termination is formed using a liquid adhesive, the wire rope first end is place in a mold. A liquid adhesive is then poured into the mold 25 through the mold opening 35 covering the end of the wire rope. The liquid adhesive may need to be heated to room temperature if the method is performed in a cold climate. Examples of usable liquid adhesives include an epoxy, such as a Devcon™ aluminum epoxies from Illinois Tool Work, of Devcon, Ill. Epoxies from 3-M of Minneapolis, Minn. are also contemplated as usable herein, as well as other epoxies that are strong and bond to steel.
[0070] The liquid adhesive is allowed to cure in the mold 25 forming a cured termination typically capable of sustaining a higher break force than the wire rope.
[0071] In the preferred embodiment the formed termination is inserted into a socket. The socket has an equipment connector on one end adapted to engage mining equipment and a wire rope connector on the other end adapted to engage the termination.
[0072] FIG. 5 shows the wire rope with termination engaging a socket 89 . The socket has a first connector end 90 adapted to engage mining equipment; and a second connector end 80 to engage the termination 10 on wire rope 15 . First connector end 90 includes hole 92 , connector 105 and connector hole 106 . Hole 92 is sized to include a bushing 100 for connection to mining equipment. Connector hole 106 is similarly sized for connection to the mining equipment. Second connector end 80 includes an upward facing opening 95 which is sized to permit an insertion of wire rope 15 and termination 10 .
[0073] Socket 89 is preferably formed from ANSI 4140 steel or EN30B material. The dimensions of socket 89 are a matter of engineering choice. However, in the preferred embodiment for a wire rope of 4½ inch diameter, socket 117 is approximately 35 inches long and 13¼ inches wide.
[0074] Moving to FIGS. 6 a and 6 b , a second preferred embodiment of a socket is shown as socket 117 . Socket 117 has body 115 . In the preferred embodiment, body 115 is formed from ANSI 4140 steel or EN30B material. First connector end 113 comprises socket ear 116 and socket ear 118 which are used for connection to mining equipment. Socket ear 116 includes hole 125 . Similarly, socket ear 118 includes hole 130 . Copper alloy bushing 131 is placed in hole 125 . Similarly, copper alloy bushing 130 is placed in hole 126 . The size and composition of the bushings are a matter of engineering choice.
[0075] Body 115 includes ear support 135 and ear support 140 . Ear support 135 and ear support 140 strengthen body 115 to prevent spreading of the ears during operation. Guide set 120 is used during operation of the mining equipment to locate a connector (not shown) during operation. The inclusion of the ear supports and guide set are optional depending on the forces applied to the system and connection pins used in operation.
[0076] Body 115 includes a bore 160 opening into frustroconical bore 165 . Bore 160 is approximately the same diameter as wire rope 15 . Frustroconical bore 165 includes circumferential slots 145 , 150 and 155 . The circumferential slots allow for lubrication of the frustroconical wedges (not yet shown). The inclusion of the circumferential slots is optional.
[0077] Body 115 further includes lateral opening 157 . Lateral opening 157 is sized to allow entry and exit of the termination.
[0078] FIG. 6 b shows cradles 161 and 162 formed in body 115 of socket 117 . The cradles are provided in the preferred embodiment to reduce weight and are optional.
[0079] FIG. 7 shows an alternate embodiment of the socket for the termination, socket 118 . Socket 118 includes upward connector 175 for connection to mining equipment. Upward connector 175 includes through hole 180 and bushing 185 . Socket 118 also includes sled 170 . In the preferred embodiment, sled 170 is welded to socket 118 to protect the socket and its internal pieces from the elements during mining operations.
[0080] FIGS. 8 a and 8 b show frustroconical wedges 190 , 195 and 200 . The frustroconical wedges are designed to fit into frustroconical bore 165 and around wire rope 15 . Frustroconical wedge 190 includes surface slot 192 . Similarly, frustroconical wedge 195 includes surface slot 197 and frustroconical wedge 200 includes surface slot 202 . The surface slots are provided to allow a circular retaining tie to be applied to the frustroconical wedges to hold them together around wire rope 15 during insertion into frustroconical bore 165 .
[0081] In the preferred embodiment, of frustroconical wedges for use with a 4½ inch wire rope, each frustroconical wedge is 8⅝ inches long and has an outer diameter of 5⅞ inches and in inner diameter of 3⅛ inches. Frustroconical wedge 190 also includes mating surface 191 , similarly, frustroconical wedge 191 has mating surface 196 and frustroconical wedge 200 has mating surface 201 . Each of the mating surfaces is flat and is designed to contact a flat mating surface of the termination during operation of the invention. Frustroconical wedges 190 , 195 and 200 when assembled form an interior bore 215 and an exterior surface 220 . The interior bore is cylindrical. The exterior surface is frustroconical.
[0082] FIG. 8 b shows that the three frustroconical wedges of the preferred embodiment are equal in size, being separated by gaps at 120 degrees. For example, gap 205 separates frustroconical wedge 190 and frustroconical wedge 195 when inserted into frustroconical bore 165 . The gaps allow for radial contraction of each frustroconical wedge toward the other frustroconical wedges toward the wire rope during operation of the invention. Gap 205 is typically ⅜ of an inch. In the preferred embodiment, there are three equally spaced and identical frustroconical wedges. However, in alternate embodiments, there can be two or more frustroconical wedges divided axially to provide compression forces to wire rope 15 .
[0083] In the preferred embodiment, the angle of inclination of the frustroconical wedges is about 96 degrees plus or minus 5 degrees. Of course, other angles of inclination will function according to engineering choice.
[0084] Each of the dimensions of the frustroconical wedges, gaps and slots can differ, depending on the size of the wire rope and the frustroconical bore. Each of the frustroconical wedges are preferably made of mild steel or an aluminum alloy.
[0085] Turning to FIGS. 9 a , 9 b and 9 c , the assembly and usage of the termination, frustroconical wedges and socket can be seen.
[0086] FIG. 9 shows an exploded view of socket 117 , wire rope 15 and termination 10 , as well as frustroconical wedges 190 , 195 and 200 . In operation, wire rope 15 is threaded through bore 160 in socket 117 . Termination 10 is then formed on wire rope 15 as previously described.
[0087] Frustroconical wedges 190 , 195 and 200 are then assembled onto wire rope 15 as shown in FIG. 9 b . A circular retaining tie 169 is then fitted into the surface slots to hold the frustroconical wedges in place on the wire rope. If desired, lubrication is placed in circumferential slots 145 , 150 and 155 . The wire rope, frustroconical wedges and termination are then pulled into socket 117 . The termination seats on mating surfaces 191 , 196 and 202 on frustroconical wedges 190 , 195 and 200 , respectively. In turn, the frustroconical wedges seat inside frustroconical bore 165 .
[0088] FIG. 9 c shows the forces applied to wire rope 15 and socket 117 during operation. Force F 1 is applied axially along the wire rope resisted by force F 3 applied to through hole 125 . A lifting force F 2 is then applied to hole 180 resulting in lifting and pulling of mining equipment. Force F 2 and F 3 are resisted by a combination of the friction on the wire rope resulting from the inward radial pressure of the frustroconical wedges on the wire rope. In turn, the inward radial pressure is created by the force F 1 acting through the contact between the termination and the mating surfaces of the frustroconical wedges. As force F 1 is increased, the radial pressure on the wire rope is also increased.
[0089] Referring to FIGS. 10 and 11 , an alternate embodiment of a drag socket according to the present invention is shown.
[0090] Drag socket 1000 includes a socket frame comprised of socket support 1002 , socket support 1003 and skid pad 1024 . Socket support 1002 and socket support 1003 are high tensile steel and are approximately two inches thick. Each is welded, inside and out to skid pad 1024 . Skid pad 1024 is also high tensile steel. Supporting and reinforcing skid pad 1024 from underneath are skid rails 1026 , 1028 and 1030 . Skid rails 1026 , 1028 and 1030 are also formed of high tensile steel. In the preferred embodiment, the skid rails are melded to the bottom of the skid pad.
[0091] Socket support 1002 includes offset ear 1054 . Offset ear 1054 includes hole 1004 in which is pressed bushing 1006 . Socket support 1002 also includes hole 1008 into which is pressed bushing 1010 . Socket support 1003 includes hole 1014 into which is pressed bushing 1012 .
[0092] Upper retaining arms 1020 and 1022 and lower retaining arms 1060 and 1061 are formed in socket support 1002 and socket support 1003 , respectively to support socket body 1024 . Socket support 1003 also includes access hole 1014 and longitudinal hole 1020 .
[0093] As can best be seen in FIGS. 10 and 11 , socket body 1024 is generally a hollow frustroconical shape having a bore 1062 . Interior of bore 1062 includes inwardly facing gradiated serrations 1140 . Inwardly facing gradiated serrations of the preferred embodiment can range between 15 and 30 degrees with a preferred range between 17 and 20 degrees in inclination. In the preferred embodiment, socket body 1024 is a high alloy steel. In the preferred embodiment, high tensile 4140 steel is used for socket body 1024 .
[0094] Within socket body 1024 and adjacent to inwardly facing gradiated serrations 1140 is releasing wedge 1032 . Releasing wedge 1032 is generally a frustroconical shape having a bore 1033 and four identical sections 1032 a , 1032 b , 1032 c and 1032 d . When assembled, sections include radial outwardly facing gradiated serrations 1142 . In the preferred embodiment, the inclination of the outwardly facing gradiated serrations can range between 15 and 30 degrees with a preferred range of between 17 and 20 degrees. Outwardly facing gradiated serrations 1142 are adjacent and engage with inwardly facing gradiated serrations 1140 . The sections of releasing wedge 1032 a - d are made of a high alloy steel. In the preferred embodiment, the high alloy steel is case hardened 4140 . Around the exterior of socket body 1024 a support ring 1035 is welded. Support ring 1035 fits within slot 1064 .
[0095] Socket body 1024 fits within and is gripped by upper retaining arm 1020 , upper retaining arm 1022 , lower retaining arm 1060 and lower retaining arm 1061 . In an alternate embodiment, the support ring is not present on the socket body and the slots 1064 and 1066 are not present in socket supports 1002 and 1003 , respectively. Interior bore 1033 of releasing wedge 1032 is a frustroconical shape having an angle of inclination of about 96 degrees plus or minus 5 degrees.
[0096] Within releasing wedge 1032 and adjacent to interior bore 1033 is locking wedge 1034 . Locking wedge 1034 forms a generally frustroconical shape having an interior bore 1035 . Locking wedge 1034 is comprised of four identical sections 1034 a , 1034 b , 1034 c and 1034 d . When assembled, circumferential slot 1052 can be seen to be centrally spaced around the exterior of the frustroconical surface of locking wedge 1034 . Interior bore 1035 is cylindrical and sized to fit the selected diameter of the wire rope on which the drag socket is placed. Locking wedge 1034 is a mild steel. In the preferred embodiment, the mild steel is medium carbon 1018 steel. Each of the sections 1034 a , 1034 b , 1034 c and 1034 d include a flat surface adjacent to load ring 1036 .
[0097] Load ring 1036 is generally cylindrical and formed in two pieces 1036 a and 1036 b . The two pieces are held together by bolts (not shown) through bolt holes 1041 a and 1041 b . When assembled, load ring 1036 has a flat surface 1039 a adjacent locking wedge 1034 and flat surface 1039 b adjacent the wire rope termination. In an alternate embodiment, load ring 1036 is not present and the wire rope termination is placed directly against the locking wedge.
[0098] As shown best in FIG. 11 , socket support 1002 includes a load plate retaining slot 1148 . Load plate seat 1150 is formed in socket support 1003 . Fitting within load plate retaining slot 1148 and load plate seat 1150 , and directly adjacent to the proximal end of socket body 1024 is load plate 1038 . Load plate 1038 is generally flat and cylindrical having a load plate bore 1039 , a hinge tab 1141 , and retaining tab 1050 . The load plate includes strengthening cylinder 1145 which is welded to the top surface of the load plate. Hinge tab 1141 fits within load plate retaining slot 1148 , retaining tab 1050 fits within load plate seat 1150 . Hinge tab 1141 includes a rounded hinge surface 1138 . In the preferred embodiment, hinge surface 1138 is a radius of approximately one inch. The rounded hinge surface allows the load plate to be rotated into position in the load plate retaining slot and load plate seat.
[0099] Load plate 1038 is maintained in place in the drag socket by pressure exerted on load plate retaining tab 1050 by load shaft 1018 . Load shaft 1018 contacts the load plate retaining tab and is aligned with and fits within longitudinal hole 1020 . Socket head cap screw 1016 is threaded into longitudinal hole 1020 from the other side and presses load shaft 1018 into contact with load plate retaining tab 1050 .
[0100] As shown in FIG. 11 , cover plate 1144 fits over access hole 1014 , longitudinal hole 1020 and load plate seat 1050 . Similarly, cover plate 1146 fits over hinge surface 1138 .
[0101] In operation, drag socket 1000 is connected a mining control line through bushing 1006 and hole 1004 . The control line is used to raise or lower the drag socket. A drag line is connected to the drag socket via bushings 1010 and 1012 and holes 1008 and 1014 . The drag line is used to pull a dump bucket forward during use.
[0102] The socket body is placed over the wire rope connected to the drag bucket through bore 1062 . A wire rope termination is formed on the free end of the wire rope (not shown) as previously described. The releasing wedge sections are then placed around the wire rope and fitted into socket body 1024 . The locking wedge sections are then placed around the wire rope and held in place by a tie fitted in circumferential slot 1052 . A wire rope is also threaded through the bore of load plate 1038 . Load ring 1036 is then placed around the wire rope and fastened adjacent the termination. A force is applied to the wire rope bringing the wire termination in contact with the load ring which in turn places a force on locking wedge 1034 and pulls it into releasing wedge 1032 fitted within socket body 1024 .
[0103] Once the wire rope, termination and socket body are in place, load plate 1038 is fitted within drag socket 1000 . Hinge tab 1141 is placed at an angle into load plate retaining slot 1148 . Load plate 1038 is rotated such that load plate retaining tab 1050 is placed within load plate seat 1150 . Load shaft 1018 is then pushed through longitudinal hole 1020 into contact with retaining tab 1050 . Socket head cap screw is then threaded into longitudinal hole 1020 pressing the load shaft into contact with the load plate retaining tab which in turn presses load plate retaining tab 1050 into load plate seat 1150 .
[0104] In operation, a force is then applied to the wire rope away from the drag socket. In practice, this force can be as high as 1.4 million pounds. The immense force placed on the wire rope is translated to the drag socket via the wire termination and the socket body. In a surprising reaction, the immense tension on the drag socket forces the releasing wedge in a direction away from the tension force on the wire rope with great force. The force tends to push releasing wedge 1032 out of socket body 1024 . In operation, the movement of the releasing wedge is resisted and prevented by load plate 1038 .
[0105] After the useful life of the wire termination has been completed, the load shaft is removed by cutting it generally in half with a torch. It can also be cut with a saw; in the field, a “sawsall” device is preferred. Once removed, load plate 1038 rotates out of the way, releasing the pressure on the releasing wedge which then, in practice, “pops” out of the socket body. Once released, the socket body can be lifted out of the drag socket and the wire termination can be replaced before further use. The advantage realized by the invention will be immediately apparent to those skilled in the art. In prior art drag sockets, the wire rope can only be removed from the drag socket with immense force such as sledge hammers or by physical cutting, resulting in a dangerous condition. The invention allows the wire rope to be disconnected safely with the use of minimum tools.
[0106] FIG. 12 depicts a mining system 1200 employing the wire rope termination that can be used with excavation equipment of various types, particularly draglines for earth moving mining equipment. The mining system 1200 utilizes wire ropes with a diameter between ¼ inches and 7 inches. The wire rope can be a single or multi-stranded and are made of steels, alloys of steel or combinations thereof.
[0107] In the mining system 1200 , termination 1201 is disposed on one end of dump rope 1220 as shown. Termination 1201 is engaged with dump rope socket 1202 . Dump rope socket 1202 connects to a bucket rigging device thru drag rope socket 1204 . Sockets such as those generally shown in FIG. 5 and FIG. 7 or any other sockets known to be compatible in the art may be used as a dump rope socket or a drag rope socket.
[0108] Referring to the socket of FIG. 7 as an example, drag rope socket 1204 has ears 118 and bushing 185 with a hole 180 . The sockets are connected in operation by aligning the ears of the dump rope sockets 1202 with the hole of the bushing of the drag rope socket 1204 . When the three holes are aligned, a throughpin is inserted to connect the ears of the dump rope socket 1202 to the upper hole in the bushing of the drag rope socket.
[0109] Referring to FIG. 12 , Drag rope socket 1204 is connected to drag rope 1226 with a termination 1210 . A drag rope link 1292 connected to drag rope socket 1204 links the socket to drag chain 1285 . On the other end of drag chain 1285 , drag hitch link 1252 connects chain 1285 to drag hitch 1254 . Drag hitch 1254 is mounted to mining bucket 1288 .
[0110] A mirror opposite of the above is also depicted in FIG. 12 . Termination 1230 is disposed on one end of dump rope 1222 . Termination 1230 is engaged with dump rope socket 1289 . Dump rope socket 1289 connects to a bucket rigging device thru drag rope socket 1206 . Similarly, dump rope socket 1289 connects to drag rope socket 1206 by aligning the ears of the dump rope socket 1289 to the bushings of drag rope socket 1206 .
[0111] Drag rope socket 1206 is connected to drag rope 1224 with a termination 1212 . A drag rope link 1291 connected to drag rope socket 1206 links the socket to the drag chain 1287 . On the other end of drag chain 1287 , a drag hitch link 1250 connects chain 1287 to hitch 1256 . Drag hitch 1256 is mounted to mining bucket 1288 .
[0112] Dump ropes 1220 and 1222 also have terminations 1218 and 1216 engaged with arch anchor sockets 1209 and 1208 . Arch anchor sockets 1209 and 1208 are connected to arch anchors 1258 and 1260 . Arch anchors 1258 and 1260 are mounted on arch 1266 . Arch 1266 is attached to the upper outside corners of mining bucket 1288 . In a preferred embodiment, arch 1260 is welded to mining bucket 1288 .
[0113] Attached to mining bucket 1288 is a trunion 1262 . Trunion 1262 has a trunion pin 1264 inserted in the trunion 1262 which allows for rotation of mining bucket 1288 . A second trunion and trunion pin are located on the opposite side of mining bucket 1288 . Trunion 1262 connects to lower hoist chain 1270 . Similarly lower hoist chain 1268 is connected to a trunion on the opposite side of mining bucket 1288 . Lower hoist chains 1268 and 1270 are connected to spreader bar 1272 . Also connected to spreader bar 1272 are upper hoist chains 1274 and 1276 . Mounted on upper hoist chains 1274 and 1276 are dump sheaves 1240 and 1242 .
[0114] Dump sheaves 1240 and 1242 are pulleys through which the dump ropes 1220 and 1222 are threaded. Connected at the other ends of the upper hoist chains 1274 and 1276 is a hoist rigging cluster 1285 . Hoist rigging cluster 1285 may vary significantly in design. Hoist ropes are freely connected to hoist rigging cluster 1278 . Hoist ropes 1278 typically connect to a crane used in the operation of the mining system.
[0115] In exemplary embodiments, the mining bucket is used for dirt or ore. In the preferred embodiment, the mining system is suspended from a crane by the hoist ropes 1078 . In operation of the mining system, the mining bucket is lowered near or set on the surface to be mined. The crane exerts a pulling force on the drag ropes which in turn pull the drag chains and the mining bucket. This process sets out to cause dirt or ore or any other materials to be collected from the surface. Once the mining bucket has collected the substances to be mined, an upward force is exerted by the crane at the hoist ropes which elevates the rear portion of the mining bucket. Simultaneously, a pulling force is exerted on the drag ropes. As the tension on the drag rope increases, the tension in the dump rope will increase resulting in the elevation of the front of the mining bucket. By increasing the elevation of the front, the collected substances are trapped in the mining bucket.
[0116] The mining bucket is dumped out by decreasing the force on the drag ropes which causes the tension in the dump ropes to decrease. This process subsequently lowers the front of the mining bucket and releases the contents of the bucket. The mining bucket is returned to its original mining position by releasing the tension in the hoist ropes and drag ropes.
[0117] The embodiments have been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the embodiments, especially to those skilled in the art.
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The invention disclosed herein provides a drag socket comprising a frame, a first attachment means for connecting the frame to a control line, a second attachment means for connecting the frame to a drag line, a socket body removably attached to the frame, a releasing wedge releasably inserted into the socket body, a locking wedge releasably inserted into the releasing wedge, a wire rope termination fused to a wire rope adjacent the locking wedge, and a load plate movably attached to the frame adjacent the releasing wedge whereby the releasing wedge is retained in the socket body when a force is applied to the wire rope. The invention also discloses a process of forming a drag socket attached to a wire rope comprising the steps of providing a drag socket frame, inserting the wire rope into a socket body in the drag socket frame, forming a termination on the wire rope, applying a releasing wedge to the wire rope and placing it into the socket body, applying a locking wedge to the wire rope and placing it into the releasing wedge, applying a load plate adjacent the socket body in a position to resist forces from the releasing wedge, and applying tension to the wire rope to move the termination to compress the locking wedge and the releasing wedge. Additionally, the invention discloses a process of releasing a drag socket from a wire rope comprising the steps of providing a drag socket frame, providing a termination on the wire rope, providing a locking wedge adjacent the termination, providing a releasing wedge around the locking wedge, providing a socket body, secured in the socket frame around the releasing wedge, providing a load plate adjacent the releasing wedge and removably secured within the frame, providing a retaining means for applying pressure to the load plate and the frame, and removing the retaining means whereby pressure on the load plate is released and the releasing wedge is released.
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RELATED APPLICATION
The subject matter of this invention is related to co-pending patent application Ser. No. 233,353 entitled "Ice-Island Construction," filed Feb. 11, 1981, Gordon F. N. Cox and Kenneth G. Nolte, inventors.
BRIEF SUMMARY OF THE INVENTION
This invention relates to ice island construction in marine areas covered by natural sea ice. In some parts of the United States off the coast of Alaska, sea ice, which may be six to seven or more feet in thickness, covers a large portion of the ocean immediately surrounding the shore area. This ice sheet may sometimes be attached to the surrounding beaches but more likely it will be detached and some of the ice sheet moves at a slow rate, e.g., two feet per day. Although this is a slow rate, the movement of the ice can exert considerable loads on offshore structures. A lot of the ice sheet is over relatively shallow water, e.g., 20 feet, and covers some of the geological structures which may contain petroleum. Thus, it is desirable to drill oil and gas wells in these areas. This can be done from fixed platforms by making an island out of gravel and the like. However, merely putting the drilling platform on steel piles is not normally satisfactory inasmuch as it is not always possible to build a pile-founded platform of sufficient strength to withstand the force of the moving ice. Other methods which have been suggested are the use of ice islands. The present invention is an improved method of construction of ice islands.
This covers a method of constructing an artificial ice island in a marine body covered at least partially by sheet ice in an environment of subfreezing temperatures. Natural and man-made sea ice is composed of sea ice crystals made up of pure ice, liquid brine inclusions, and solid salts. As the ice temperature or salinity increases, the ice brine volume increases via phase relationships. The greater the ice brine volume, the weaker the ice. Fresh water ice is also stronger than sea ice. Further, brine tends to migrate in ice from top to bottom and weakens the bottom of the ice.
In our preferred embodiment for constructing an artificial ice island, we first mine blocks of ice from the natural ice sheet in the surrounding area. We then cool these mined blocks by stacking or storing them such that the air has contact with a good part of the ice block. Inasmuch as the ice blocks are relatively small, e.g., 2×4×6 feet, the blocks will rapidly approach the ambient temperature.
The ice island is built by stacking ice blocks directly on top of the sheet ice on the selected area for the island without any step of first building up a lower level by normal flooding and freezing. In one embodiment we construct a ring of ice blocks about the area selected and then fill in the interior of the ring in a systematic manner to minimize the deflection of the ice sheet inside the ring. A ring is cut around the selected area to separate the ice island from the surrounding ice to eliminate or prevent deflections in the surrounding natural ice sheet as the selected island area is sunk by the weight of the ice blocks.
In what may be my preferred embodiment, we construct a small rectangular shaped island section by stacking ice blocks on an area small enough so that the natural ice does not fail within the area if a trench is cut through the ice sheet around the section. We then build additional sections until the desired size of the island is obtained.
A better understanding of the invention can be had from the following description taken in conjunction with the drawings.
DRAWINGS
FIG. 1 illustrates an ice island made by constructed ice on top of a natural ice sheet.
FIG. 2 illustrates lifting first ice block from an ice sheet.
FIG. 3 illustrates the first phase of constructing a section of an ice island from mined ice blocks.
FIG. 4 illustrates the final construction of one section of an ice block island.
FIG. 5 illustrates an ice block ring outlining the area of an artificial ice island to be constructed.
FIG. 6 illustrates dividing the ice ring of FIG. 4 into quadrants.
FIG. 7 illustrates subdividing the quadrants of FIG. 6.
FIG. 8 illustrates cutting slots around the ice block ring to relieve stress.
FIG. 9 illustrates variations in temperature of an ice block ice island during construction in water.
FIG. 10 illustrates varying capacity of a 2-foot-thick sheet ice.
DETAILED DESCRIPTION OF THE INVENTION
In addition to requiring adequate ice strength to resist ice movement, an ice island must have sufficient sliding resistance on the sea floor. This is accomplished by making the island large enough so that the contact area and weight of the island produces the required sliding resistance. Islands on the order of 300 feet in diameter and 50 feet thick have been considered in the public literature. As shown in FIG. 1, an ice island has been made on an area having a sea floor 10, sea water 12, a natural ice sheet 14, and constructed ice 16. This ice island can be constructed by flooding the area on top of ice sheet 14 on which it is desired to produce the ice island. The water is confined to the selected area where it freezes and additional water is continually added until the constructed ice is the desired thickness. As can be seen in FIG. 1, the weight of the constructed ice 16 deforms the layer of the natural ice 14 until eventually it rests on the bottom 10.
Attention is directed to FIG. 3 to illustrate the construction of an ice island from mined ice blocks. An area, which may be in the form of a square 48 on the ice sheet 47, is selected and is covered by a layer 46 of ice blocks 44. A slot 50 is cut in ice sheet 47 completely around area 48 so as to prevent excessive stresses to the surrounding ice sheet 47 as additional layers of ice blocks 44 are added. As shown in FIG. 4, additional layers of ice blocks are added until the "cut-out" area 48 of the ice sheet rests on the sea floor 52. What is illustrated can be described as an ice island section. Additional sections can be built adjacent the previously constructed sections until the desired size of the ice island is obtained.
There are four steps needed in the construction of an artificial ice island from mined ice blocks. They include mining, curing, transportation, and bonding. Mining the ice blocks will now be discussed. Mining the ice blocks from a natural ice sheet, such as 47, requires a snow plow, surveying equipment, several ice-cutting machines, and a crane. Since uniform blocks are needed to construct the island, a survey crew first lays out lines on the ice to be cut by the ice trenching machines. Conditions may required that the snow be plowed off the ice surface. Once the cutting lines have been marked on the ice, such as by spray paint, the blocks are cut out by the ice cutting machines. The first block may be removed by coring a hole or holes in the block and freezing in a pipe with holes, a hook or eye bolt at the top end, such as illustrated in FIG. 2. The block 44 is lifted from the ice sheet using a crane with a cable 49 attached to the frozen bolt 42. Subsequent blocks may be removed by using a large bucket or ice tongs attached to the crane. If a 4×8 foot block is excavated from the 2 foot thick ice, a six-ton capacity crane would be required to lift the blocks. Ice cutting machines having cutting speeds up to 10 feet per minute in 4 to 6 foot thick ice have been tested by the Naval Civil Engineering Laboratory.
Once the ice blocks 44 have been excavated from the natural ice sheet, the blocks should be allowed to cure before they are used for construction. This may be accomplished by placing the ice blocks on beams or slat-like material with the natural top up so that cold air substantially surrounds the block. The block is allowed to cool until the lower portion of the block has reached the ambient temperature which may take several days, e.g., seven to ten. As the blocks cool, the concentrated brine in the ice will drain out by brine expulsion and gravity drainage. This decrease in ice temperature and salinity results in higher ice strength. Furthermore, the brine which has drained out of the ice blocks during the curing stage will not later accumulate at the base of the ice island by gravity drainage and cause ice deterioration. The colder temperature of the ice blocks will also facilitate welding them together and produce a stronger ice block bond.
Brine drainage may cause the underside of the ice blocks to be rough and irregular. It may therefore be necessary to turn the blocks over and position them upside down. The rough ice on top may be scraped off with a plow. Placing the blocks in this manner also allows the warmer lower portion of the ice blocks to cool more rapidly. After the blocks have cured, they must be transported and positioned at the construction site. Large payloaders equipped with a fork lift and crane may be used for this task.
The ice blocks are bonded to the underlying ice, that is the top of the sheet ice on the specific area at which it is desired to build the ice island. Before the ice blocks are positioned, the ice surface is flooded with water and allowed to form a slush layer. The cured ice blocks are then placed on the slush and the excess water is quickly squeezed out and the slush freezes since the base of the ice blocks is at ambient temperature, such as -25° C. Vertical cracks between the blocks are then flooded with water. If it is found that the water runs out, as between large cracks, the cracks can be filled with saturated snow. The greater the water saturation of the snow, the stronger the resulting bond.
Unlike most other artificial ice construction techniques, such as flooding and spraying, the build-up rate for an ice structure constructed from ice blocks is not strongly dependent on the water freezing rate and the weather conditions. The main construction building material, i.e., the blocks, are already frozen. Because the ice blocks are cured and near ambient temperature, the water used to cement the blocks together also freezes rapidly. Thus, the build-up rate is largely governed by the rate at which the blocks are mined from the ice sheet, cured, and transported and positioned at the site. In the arctic area, island construction will most likely take place during the latter part of November and all of December and January. During this period, the ice will increase in thickness from 2 to 4 feet and have an average thickness of about 3 feet.
In addition to a high build-up rate, ice block structures also have the advantage of lower initial ice temperature and salinity than flooded ice. Under typical winter conditions, the sea ice blocks have an average temperature of about -10° C. and an average salinity of about 6 parts per thousand. For a reference on this, see: "Cox, G. F. N. and Weeks, W. F. (1974), Salinity Variations In Sea Ice. Journal of Glaciology, Vol. 13, no. 67, p. 109-120." In contrast, newly flooded ice constructed from the same sea water has a temperature close to its melting point -2° C. and an average salinity of about 30 parts per thousand. For a reference on this, see: "Dykins, J. E. and Funai, A. J. (1962), Point Barrow Trials--FY 1959. Investigations on Thickened Sea Ice. Naval Civil Engineering Laboratory, Technical Report R189." The sea ice blocks are therefore much stronger. The strength of the ice blocks can be further increased by allowing additional time to cure.
In constructing an ice structure from ice blocks, it is not the ice block strength that is of the most importance, but the strength of the ice block/ice block bond. If fresh or low salinity water is used to bond the blocks together, an ice island of sufficient size would have adequate structural integrity to resist ice movement.
Since the temperature of the sea water and the initial temperature of the sea bed are at the freezing point of sea water, the lower portion of the ice island is warmer and therefore weaker than the overlying ice. The most critical place along which internal shear is most likely to occur as a result of sea ice movement is the bonding layer just above the natural ice layer or the ice sheet. It is expected that the initial salinity of this layer will be about 35 parts per thousand, i.e., sea water salinity. However, since the ice block and the natural sea ice surface will be at ambient temperature most likely below -25° C., the temperature of the bonding layer will be close to the precipitation temperature of NaCl that is 31 23° C. The brine volume of the ice will be small and the ice will have a high strength. After the first layer of ice blocks is frozen to the ice sheet, the bonding layer between the ice blocks and the ice sheet will warm up. As each successive layer of ice blocks is added, the temperature of this critical layer will further increase until the ice structure grounds on the sea floor. This increase is due to having the warmer water underneath it. After grounding, the temperature in the lower portion of the ice island decreases since the underlying soil is cooled by heat conduction through the ice structure.
The variation in ice temperature during construction of an ice island in 20 feet of water is illustrated in FIG. 9. Maximum possible temperatures (steady-state) are given, assuming a constant ambient temperature of -20° C. The mean temperature during December and January along the north Alaskan coast is about -25° C. Initially, the temperature of the bonding layer 90 between the ice 89 blocks 91 and the natural ice 89 will be about -20° C. (curve A). The ice temperature of the bonding layer will then approach -12° C. before the next layer of blocks is added in an effort to obtain thermal equilibrium (curve B). As the island is constructed, the temperature at all levels increases and approaches the steady-state profile shown by the solid line in curve C just at grounding. The temperature of the critical layer will increase to about -5° C. After grounding, this critical layer will then decrease in temperature by an unknown amount as a result of cooling of the underlying soil. A possible temperature profile sometime after grounding is shown by the dashed line 93 in curve C.
From estimates of constructed ice shear strength and field data, flooded ice having a salinity of 15 parts per thousand and a temperature of -5° C. would have a shear strength of about 30 psi. Based on data obtained by Dykins and Finai (1962), supra, it is assumed that the salinity of the bonding layer 90 will decrease by 50% during construction as a result of brine drainage with the underlying sea water. This shear strength exceeds the estimated required shear strength of 9 psi for a 300 foot diameter ice island to resist internal shear caused by ice movement, i.e., movement of the ice sheet.
One should next consider the bearing capacity of the ice sheet. For example, if a 300 foot diameter ice structure is to be used, over 2000 8×4×2 foot ice blocks will be needed for each ice block layer. As each cubic foot of ice weighs about 57 lbs, the bearing capacity of the natural ice sheet should be examined to determine how the ice block should be positioned. Uncontrolled failure of the ice sheet under concentrated loads may result in flooding of the working area, loss of ice blocks, and make access to the construction site impossible. Thus, I shall now consider a pattern or method in which I will lay the ice blocks on the sheet ice. Assuming that the ice sheet may be regarded as an elastic plate on an elastic foundation, the following approximation has been obtained. ##EQU1## where P cr =load at which the plate cracks,
σ f =flexural strength of ice (100 psi),
h=ice thickness,
a=radius of load,
γ=density of sea water (64.3 pcf), and
E=ice elastic modulus (3.0×10 5 psi).
Initially, the natural ice sheet will usually be about 2 feet thick and have a flexural strength of about 100 psi and an elastic modulus of 3.0×10 5 psi. The ice blocks mined from the ice sheet will also be 2 feet thick. Equation (1) has been used to estimate how many 8×4×2 ft ice blocks can be positioned on the ice together before the ice sheet cracks. The results are plotted in FIG. 10. An ice block density of 57 pcf was used to calculate the load. FIG. 11 indicates that cracking of the ice sheet will occur once the 2-foot thick ice blocks have been positioned in a circle having a radius of about 14 feet. This area corresponds to only 19 ice blocks, about one percent of the total number of ice blocks required for each layer. Thus, during construction of a 300-foot diameter ice structure, failure of the ice sheet will occur. A plan is devised to minimize ice failure and unwanted flooding in the working area, and cause the ice sheet to fail in a controlled manner outside the perimeter of the area selected for the island.
One solution is to construct a ring of ice blocks and then fill in the interior of the ring in a systematic manner to minimize the deflection of the ice inside the ring. For example, a 300-foot diameter ice ring, several ice blocks wide, would first be constructed as ring 60 on the ice sheet (FIG. 5). Since the ice blocks are distributed over a large area, failure of the ice sheet should not occur. At the same time, a grounded ice block road should be constructed to the ice ring to provide access to the ring surface and interior. The road should be oriented in the direction of least likely ice movement, probably toward the coast. Once the ring and access road have been constructed, the next step is to divide the ring into quadrants by ice block line 62, as in FIG. 6, taking care not to induce cracking in the interior. Each quadrant is then divided into smaller sections (FIG. 7) by ice block lines 64, and so on until the ring interior is completely filled. What is being accomplished is to distribute the load over a large area in a manner that as the section sinks, the distance between adjacent ice block lines is sufficiently short so that failure of the non-covered ice between ice blocks does not fail. During this period, severe deflections will occur in the surrounding natural ice sheet. The deflections can be eliminated by cutting the ring from the surrounding ice (FIG. 8). Illustration A of FIG. 8 shows bending of the ice sheet which may result in cracking of the sea ice, whereas such cracking is prevented in Illustration "B" by cutting a trench or ditch 49 around the island. The ice blocks in the ring should prevent flooding of the interior. Subsequent ice block layers are constructed in a similar manner until the ice structure is grounded on the sea floor. Once the structure has grounded, the ice blocks may be positioned in any convenient manner.
An alternate and possibly better solution is to construct only a small portion of the total area, e.g., 24-foot by 24-foot sections of the submerged part of the ice island, at a time. After the 18 blocks are laid out, a slot would be cut around the blocks to allow them to reach isostatic equilibrium and relieve the stress in the surrounding ice as described above in relation to FIGS. 3 and 4 and then construct neighboring sections in the same manner until the desired ice island area is obtained. Vertical cracks between the sections should freeze due to the large mass of the cold ice blocks. Once the lower portion of the ice island has grounded, the blocks may be positioned in any convenient manner.
As we stated above, in addition to requiring sufficient ice strength to resist ice movement, an ice island must be large enough to have sufficient sliding resistance on the sea floor to prevent movement. The following is an approximation for H the ice island thickness: ##EQU2## where σ c =unconfined compressive sea ice strength,
h=ice thickness,
D=ice island diameter,
d=water depth,
ρ i =constructed ice density (57 pcf),
ρ w =sea water density (64.3 pcf), and
φ=friction angle of the ice on sea floor.
While the above description has been made in great detail, various modifications can be made thereto without departing from the spirit or scope of the invention.
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An ice island is constructed in a marine area having a sheet of natural ice by mining ice blocks from the ice sheet, curing the blocks and placing the cured blocks directly on the ice sheet until the natural sheet touches bottom and the desired weight of the ice island is obtained. Methods are disclosed for special placement of the blocks to prevent overstressing the natural ice sheet.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional of U.S. Provisional Patent Application Ser. No. 61/946,252, filed Feb. 28, 2014, which is incorporated herein by reference.
[0002] Priority of U.S. Provisional Patent Application Ser. No. 61/946,252, filed Feb. 28, 2014, is hereby claimed.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] Not applicable
REFERENCE TO A “MICROFICHE APPENDIX”
[0004] Not applicable
BACKGROUND
[0005] Conventionally available are side entry compact valves including a valve ball having integral opposed trunnions rotating in upper and lower trunnion support plates, which plates are supported by the valve body, with right and left valve seats and seals for sealing, and all of which components are inserted and removed from the valve body via one of the side openings of the valve, and which components are held in place during use with a threaded retainer.
[0006] The “compact” nature of compact valves generally results from a short or compact valve body having opposed “open” ends each defining a flange closure seat which is engaged by and establishes sealing with a flange closure which may be defined by a flange of a pipe section of the manifold or other piping assembly. Since no other body closure members are provided, the overall length of the valve body is short and compact as compared with the valve body structures of conventional ball valves. Accordingly, the compact manifold ball valves can be installed in piping systems such as flow control manifolds in offshore production platforms where minimal space is available.
[0007] One example of a type of side entry compact valve is disclosed in U.S. Pat. No. 6,669,171 for a “Compact Manifold Trunnion Ball Valve” which is incorporated herein by reference. The upper and lower trunnion support plates prevent the valve ball from transferring downstream loads to the seals and seats reducing frictional forces between the ball and seals.
[0008] However, in conventionally available side entry compact valves generally a single piece retainer is threadably connected to the valve body, wherein such single piece retainer must be rotated relative to both the valve body and the adjacent valve seat with such relative rotation causing wear to the seals between the valve seat and retainer along with the seals between the retainer and valve body.
[0009] It has been found that sealing elements in compact valves have a significant risk of becoming excessively worn and/or damaged during valve assembly and/or disassembly. It has been found that relative rotational movement between the valve components and the seals increase the risk of substantial wear and/or damage to the seals.
[0010] It would be advantageous to have a retainer both threadably connected to the valve body and concentrically positioned in said body, wherein there is little no relative rotational movement between sealing elements for the valve seat and retainer.
[0011] It would be advantageous to have a retainer both threadably connected to the valve body and concentrically positioned in said body, wherein there is little no relative rotational movement between sealing elements for the valve body and retainer.
SUMMARY
[0012] One embodiment generally relates to compact ball valves for use in conduit manifold systems. More particularly one embodiment includes a compact manifold ball valve having a valve body, valve ball, and valve stem; the valve body including a valve chamber having first and second ends, and a first flow passage intersecting the valve chamber and valve ball. The valve ball can be trunnion supported with at least one trunnion support element. A pair of movable seat assemblies can be used to seal the valve ball to the valve body. In one embodiment the above referenced components can be held in place during use with a threaded two piece retainer.
[0013] In one embodiment the two piece retainer longitudinally holds in place at least one trunnion support element restricting the amount of longitudinal movement of said trunnion support element. In one embodiment two trunnion support elements are longitudinally held in place with restricted to no longitudinal movement allowed.
[0014] In one embodiment is provided a retainer which is both threadably connected to the valve body and concentrically positioned in said body includes a sealing portion having little to no relative rotational movement between sealing elements for the valve seat and retainer section during valve assembly.
[0015] In one embodiment is provided a two piece retainer which is both threadably connected to the valve body and concentrically positioned in said body, wherein the two piece retainer includes first and second sections, wherein the first section having little to no relative rotational movement between sealing elements for the valve seat and retainer section during valve assembly.
[0016] In one embodiment is provided a two piece retainer which is both threadably connected to the valve body and concentrically positioned in said body, wherein the two piece retainer includes first and second sections, wherein the second section is threadably connected to the valve body such that rotation of the first section relative to the valve body causes either tightening or loosening of the first section relative to the valve body.
[0017] In one embodiment is provided a two piece retainer including first and second sections, wherein the second section is a ring, and rotational movement of the second section causes linear movement of the second section.
[0018] In one embodiment rotational movement of the first section relative to the valve body is constrained and/or prevented. In one embodiment at least one locking pin rotationally locks the first section relative to the valve body while allowing linear movement of the first section relative to the valve body.
[0019] In one embodiment rotational movement of the first section relative to the valve body is constrained and/or prevented while relative linear movement is allowed. In one embodiment the first section includes a detachable sealing element along with at least one locking pin that rotationally locks the first section relative to the valve body while simultaneously allowing linear movement of both the first section and sealing element relative to the valve body.
[0020] In one embodiment the first section includes a first detachable sealing element and the valve seat includes a second detachable sealing element. In this embodiment the first section also includes at least one locking pin that rotationally locks the first section relative to the valve body while simultaneously allowing linear movement of the first section (and the first sealing element when attached to the first section) relative to the valve body, along with relative movement between the valve seat (and second sealing element when attached to the valve seat) with respect to the first section. In one embodiment the first sealing element forms a seal between the first section and valve body, while the second sealing element forms a seal between the first section and valve seat.
[0021] In one embodiment the first section includes first and second detachable and spaced apart sealing elements, along with at least one locking pin that rotationally locks the first section relative to the valve body while simultaneously allowing linear movement of the first section (and the first and second sealing elements when attached to the first section) relative to the valve body. In one embodiment the first sealing element forms a seal between the first section and valve body, while the second sealing element forms a seal between the first section and valve seat.
[0022] In one embodiment the locking pins are have a relatively small shear force where a rotational force exceeding a predefined force will cause the shear pin(s) to shear and allow rotational movement between the first section and valve body.
[0023] In one embodiment two locking pins are used which are symmetrically spaced about the first section of the retainer.
[0024] In various embodiments at least 50 percent of the longitudinal length of the first retainer section enters the interior portion of the valve body. In various embodiments at least 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, and 100 percent of the first retainer section enters the interior portion of the valve body during assembly. In various embodiments the amount of longitudinal length of the first retainer section entering the valve body during assembly is between about a range of any two of the above referenced percentages.
[0025] In various embodiments at least 50 percent of the longitudinal length of the second retainer section enters the interior portion of the valve body. In various embodiments at least 55, 60, 65, 70, 75, 80, 85, 90, 95, 96, 97, 98, 99, and 100 percent of the second retainer section enters the interior portion of the valve body during assembly. In various embodiments the amount of longitudinal length of the second retainer section entering the valve body during assembly is between about a range of any two of the above referenced percentages.
[0026] In one embodiment the retainer pins are less than about 3 mm in diameter. In various embodiments the retainer pins are less than about 3, 2.5, 2.0, 1.9, 1.8, 1.7, 1.6, 1.5, 1.4, 1.3, 1.2, 1.1, 1.0, 0.9, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, and 0.1 mm. In various embodiments the diameters of the retainer pines are between about any two of the diameters specified in this paragraph.
[0027] In various embodiments the first retainer section includes a plurality of openings and the valve body includes a plurality of openings which match the plurality of openings for the first retainer section. In various embodiments a plurality of retainer pins can be placed in the plurality of openings to rotationally lock the first retainer section with respect to the valve body.
[0028] In various embodiments the second retainer section locks in place the plurality of retainer pins in their respective plurality of openings.
[0029] While certain novel features of this invention shown and described below are pointed out in the annexed claims, the invention is not intended to be limited to the details specified, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the spirit of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.”
[0030] The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0031] For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
[0032] FIG. 1 is a sectional side view of one embodiment the showing a compact valve body with a two piece retainer holding in position the valve ball and trunnion support elements along with the valve ball seats.
[0033] FIG. 2 is an end view of the compact valve shown in FIG. 1 , but all valve components shown in an exploded condition from the second end of the body of the compact valve.
[0034] FIG. 3 is a sectional view of the compact valve shown in FIG. 4 taken along the lines 3 - 3 .
[0035] FIG. 4 is a perspective view of the first retainer section shown in the valve of FIG. 1 .
[0036] FIG. 5 is an end view of the first retainer section shown in FIG. 4 .
[0037] FIG. 6 is a sectional view of the first retainer section shown in FIGS. 4 and 5 , taken along the lines 6 - 6 .
[0038] FIG. 7 is a perspective view of the second retainer section shown in the valve of FIG. 1 .
[0039] FIG. 8 is an end view of the second retainer section shown in FIG. 7 .
[0040] FIG. 9 is a sectional view of the second retainer section shown in FIGS. 7 and 8 , taken along the lines 9 - 9 .
[0041] FIG. 10 is a partially exploded perspective view of the valve of FIG. 1 with the two piece retainer of FIGS. 4 through 9 positioned to be installed in the valve body where the valve ball and seats are already installed in the valve body.
[0042] FIG. 11 is a sectional view of the partially exploded view of the embodiment shown in FIG. 10 taken along with lines 11 - 11 .
[0043] FIGS. 12 through 15 schematically indicate the assembly steps of placement of the first and second retainer sections into the valve body.
[0044] FIG. 12 shows both the first and second retainer sections before placement in the valve body of the compact valve.
[0045] FIG. 13 shows the valve of FIG. 12 where the first retainer section has been partially inserted into the valve body, but the second retainer section has not yet been inserted into the valve body.
[0046] FIG. 14 shows the valve of FIG. 12 where both the first and second retainer sections have been partially inserted into the valve body.
[0047] FIG. 15 shows the valve of FIG. 12 where both the first and second retainer sections have been completely inserted into the valve body.
[0048] FIG. 16 is a perspective view of the valve body taken from the first end of the valve body.
[0049] FIG. 17 is a perspective view of the valve body taken from the second end of the valve body.
[0050] FIG. 18 is a side view of the second end of the valve body.
[0051] FIG. 19 is a sectional view of the valve body taken along the lines 19 - 19 .
[0052] FIG. 20 is a perspective view of the valve ball shown in the valve of FIG. 1 .
[0053] FIG. 21 is an end view of the valve ball shown in FIG. 16 .
[0054] FIG. 22 is a sectional view of the valve ball in FIGS. 20 and 21 , taken along the lines 21 - 21 .
[0055] FIG. 23 is a perspective view of the trunnion support element shown in the valve of FIG. 1 ;
[0056] FIG. 24 is an end view of the trunnion support element shown in FIG. 23 .
[0057] FIG. 25 is a sectional view of the trunnion support element shown in FIGS. 23 and 24 , taken along the lines 25 - 25 .
[0058] FIG. 26 is a perspective view of the seat shown in the valve of FIG. 1 .
[0059] FIG. 27 is an end view of the seat shown in FIG. 26 .
[0060] FIG. 28 is a sectional view of the seat shown in FIGS. 26 and 27 , taken along the lines 28 - 28 .
[0061] FIG. 29 is a perspective view of the bonnet shown in the valve of FIG. 1 .
[0062] FIG. 30 is an end view of the bonnet shown in FIG. 29 .
[0063] FIG. 31 is a sectional view of the bonnet shown in FIGS. 29 and 30 , taken along the lines 31 - 31 .
[0064] FIG. 32 is a perspective view of the stem shown in the valve of FIG. 1 .
[0065] FIG. 33 is a side view of the stem shown in FIG. 32 .
[0066] FIG. 34 is a sectional view of the stem shown in FIGS. 32 and 33 , taken along the lines 34 - 34 .
DETAILED DESCRIPTION
[0067] Detailed descriptions of one or more preferred embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate system, structure or manner.
[0000] Overview of Compact Valve with Two Piece Retainer
[0068] FIG. 1 is a sectional side view of one embodiment showing an assembled compact valve body 20 with a two piece retainer 1100 (first 1200 and second 1300 sections) installed in the valve body 20 retaining a valve ball 200 and seats 1000 , 1000 ′ in the valve body 20 . FIG. 2 is an end view of compact valve 10 , showing certain valve components in an exploded condition—this end view being taken from the second end 40 of body 20 . FIG. 3 is a sectional side view of the compact valve 10 taken along the lines 3 - 3 generally showing all valve components in an exploded condition.
[0069] FIG. 10 is a partially exploded perspective view of compact valve 10 showing valve body 20 with the two piece retainer 1100 (first 1200 and second 1300 sections) positioned to be installed in the valve body 20 where the valve ball 200 and seats 1000 , 1000 ′ are already installed in the valve body 20 . FIG. 11 is a sectional view through the partially exploded view of the compact valve 10 taken along with lines 11 - 11 .
[0070] In one embodiment compact valve 10 can comprise body 20 , valve ball 200 , and two piece retainer 1100 . Valve ball 200 can be rotatably and sealably connected to body 20 . Valve body 20 can include flow passage 60 . Valve ball 200 can include flow passage 270 . To allow flow through flow passage 60 of valve body 20 , flow passage 270 can be aligned, either partially or wholly, with flow passage 60 . To restrict or prevent flow through flow passage 60 , flow passage 270 can be non-aligned, either partially or wholly, with flow passage 60 . Alignment of flow passage 270 can be made by rotating valve ball 200 relative to valve body 20 .
[0071] Valve ball 200 can be rotatably supported in body 20 by trunnions 220 and 260 . Trunnion 220 can be rotatably connected to trunnion support element 400 . Trunnion 260 can be rotatably connected to trunnion support element 450 . Valve ball 200 can be operatively connected to stem 500 , such as through stem recess 220 . Stem recess 230 can have a rectangular cross section, although other types of operably connections can be made such as square, ribbed, or any non-circular shaped recess; or any type of mechanical connection.
[0072] In one embodiment rotating stem 500 , such as in the direction of arrow 1500 , causes similar rotation of valve ball 200 . Stem 500 itself can be rotatably connected to body 20 . Trunnion support element 400 can be supported in body 20 . Accordingly, although valve ball 200 can rotate relative to valve body, longitudinal movement (i.e., arrows 1510 , 1520 ) can be restricted and/or prevented depending on the relative amount of longitudinal movement allowable between: valve ball 200 and trunnion support elements 400 , 450 ; and trunnion support elements 400 , 450 and valve body 20 . It is preferred that longitudinal movement between valve ball 200 and valve body 20 be minimized. It is also preferred that stem 500 be aligned with cylindrical opening 420 of trunnion support element 400 (and cylindrical opening 470 of second trunnion support element 450 ) as misalignment can cause difficulty in turning valve ball 200 .
[0073] Valve ball 200 can be sealably connected to valve body 20 by means of opposed and biased seats 1000 and 1000 ′. Seats 1000 and 1000 ′ can be supported in valve body 20 and biased toward valve ball 200 , respectively in the directions of arrows 1510 and 1520 . Accordingly, where flow passage 270 of valve ball 200 is rotated 90 degrees in relation to flow passage 60 of valve body 20 (e.g., in direction of arrow 1500 ), flow is cut off by the sealing effect of seats 1000 and 1000 ′. As the relative rotation between flow passage 270 of valve ball 200 and flow passage 60 of valve body 20 is reduced from 90 ninety degrees, the restriction of flow by valve ball 200 is reduced. Maximum flow through valve 10 is achieved when flow passage 270 of valve ball 200 is aligned with flow passage 60 of valve body 20 (i.e., when the relative rotation is zero degrees).
[0074] Generally two piece retainer 1100 can retain the valve components inside valve body 20 . FIGS. 4 through 9 show various views of components of the two piece retainer 1100 which is generally comprised of rotationally static first section 1200 and rotating second section 1300 .
[0075] FIG. 4 is a perspective view of first retainer section 1200 . FIG. 5 is an end view of the first retainer section 1200 . FIG. 6 is a sectional view of first retainer section 1200 taken along the lines 6 - 6 . First section 1200 can include first and second shoulders 1250 , 1260 along with first and second circumferential areas 1252 , 1262 which accommodate seat 1000 . Preferably, planar surface 1222 on second end limits the amount of longitudinal movement of first 400 and second 450 trunnion support elements which second retainer section 1300 is tightened in valve body 20 . When retainer 1100 is installed in valve body 20 , there exists a defined longitudinal length between planar surface 1222 of second retainer section 1200 and third shoulder 116 of valve body 20 so that trunnion support elements 400 , 450 each have a limited defined space to sit in (i.e., the space between planar surface 1222 and third shoulder 116 ).
[0076] Preferably, a seal is maintained between first retainer section 1200 and valve body 20 , which can be a lip seal. To facilitate this sealing, seal recess 1224 can be provided which can accommodates seals 1044 , which seals can each include a lip seal and back-up ring (the back up ring increasing the sealing pressure rating and resisting extrusion of the lip seal). In one embodiment one or both of the back-up rings can be omitted.
[0077] Also preferably, a seal is maintained between first retainer section 1200 and valve seal 1000 , which can be an o-ring type seal. To facilitate this sealing, seal recess 1040 can be provided which can accommodates seals 1042 , which seals can each include an o-ring and back-up ring (the back up ring increasing the sealing pressure rating and resisting extrusion of the o-ring).
[0078] FIG. 7 is a perspective view the second retainer section 1300 . FIG. 8 is an end view of second retainer section 1300 . FIG. 9 is a sectional view of second retainer section 1300 taken along the lines 9 - 9 . Second retainer section can be a threaded ring like section having first end 1310 and second end 1320 with a central opening 1305 . A threaded area 1340 can be used to threadably connect second section 1300 to valve body 20 . A plurality of spaced apart openings 1314 can be used to connect section retainer section 1300 to a tool for tightening or loosening of second retainer section relative to valve body 20 .
[0000] Assembly and Disassembly of Valve with Two Piece Retainer
[0079] FIG. 1 is a sectional side view of the assembled compact valve 10 using two piece retainer 1100 to hold in place various internal valve components. FIG. 2 is an end view of the compact valve 10 , but all valve components shown in an exploded condition from the second end 40 of valve body 20 of compact valve 10 . FIG. 3 is a sectional view of exploded compact valve 10 taken along the lines 3 - 3 .
[0080] FIGS. 10 through 15 schematically indicate the assembly steps of placement of the retainer 1100 's first 1200 and second 1300 retainer sections into valve body 20 . FIG. 10 is a partially exploded perspective view of one embodiment of valve 10 showing compact valve body 20 with the two piece retainer 1100 positioned to be installed in valve body 20 where the valve ball 200 , trunnion support elements 400 , 450 , and seats 1000 , 1000 ′ are already installed in the valve body 20 . FIG. 11 is a sectional view of the partially exploded view of valve 10 taken along with lines 11 - 11 .
[0081] FIG. 12 shows both the first 1200 and second 1300 retainer sections before placement in valve body 20 of compact valve 10 . Arrow 1400 schematically indicates the longitudinal movement which will occur in retain 1100 for pieces 1200 , 1300 , although second retainer section 1300 which include rotational movement.
[0082] First section can include detachable seal 1226 which sits in recess 1224 . Detachable seal 1226 can be a lip type seal. In one embodiment seal 1226 can include an extrusion ring to prevent extrusion of seal 1226 . In one embodiment seal 1226 can be an o-ring type seal.
[0083] Seat retainer 1000 section can include detachable seal 1042 which sits in recess 1040 . Detachable seal 1042 can be various conventionally available seals. In one embodiment seal 1042 can include an extrusion ring to prevent extrusion of seal 1042 . In one embodiment seal 1042 can be an o-ring type seal.
[0084] FIG. 13 shows valve 10 where first retainer section 1200 has been partially inserted into valve body 20 , but second retainer section 1300 has not yet been inserted into valve body 20 . At this point seal 1226 has not yet made contact with valve body 20 . Seal 1224 is shown in the vicinity of threads 140 . Also at this point seal 1042 of seat 1000 has not yet made contact with first retainer section 1200 . Second retainer section 1300 is shown on the outside of valve body 20 . Arrow 1410 schematically indicates that second retainer section 1300 will be rotated relative to valve body 20 , however, during such rotation in the direction of arrow 1410 first retainer section will remain rotationally fixed relative to valve body 20 (and also relative to valve seat 1000 ). Arrow 1400 schematically indicates longitudinal movement of first retainer section 1200 relative to valve body 20 while simultaneously remaining rotationally static relative to valve body 20 . In FIG. 13 is also shown retaining pins 1246 , 1246 ′ in openings 1247 of first retainer 1200 . Retainer pin 1246 will seat in opening 180 for restricting rotational movement of first retainer section 1200 relative to valve body 20 . Retaining pin 1246 ′ will seat in opening 182 for restricting rotational movement of first retainer section 1200 relative to valve body 20 (rotational movement schematically indicated by arrow 1410 ). However, both retaining pins 1246 , 1246 ′ allow linear movement of first retainer section 1200 relative to valve body 20 (schematically indicated by arrow 1400 ).
[0085] FIG. 14 shows valve 10 where both first 1200 and second 1300 retainer sections have been partially inserted into valve body 20 . Threads 1340 of second retainer section 1300 have now engaged threads 140 of valve body. Seal 1226 has engaged surface 132 of valve body 20 . Seal 1042 has engaged surface 1262 of first retainer section 1200 . Both retaining pins 1246 , 1246 ′ allow linear movement of first retainer section 1200 relative to valve body 20 (schematically indicated by arrow 1400 ). Rotational movement (schematically indicated by arrow 1410 ) of second retainer section 1300 , with its threads 1340 engaging threads 140 of valve body 20 , will cause second retainer section 1300 to move in the direction of arrow 1400 and push first retainer section 1200 in the direction of arrow 1400 .
[0086] FIG. 15 shows valve 10 where both first 1200 and second 1300 retainer sections have been completely inserted into valve body 20 . Continued rotational movement of second retainer section 1300 compared to FIG. 14 (schematically indicated by arrow 1410 ), with second retainer 1300 threads 1340 engaging threads 140 of valve body 20 , will cause second retainer section 1300 to continue to also move linearly in the direction of arrow 1400 and continue to push first retainer section 1200 linearly in the direction of arrow 1400 . During the linear pushing by second retainer section 1300 , first retainer section 1200 moves only linearly (schematically indicated by arrow 1400 ) and is rotationally constrained by pins 1246 and 1246 ′. In this manner the seals 1226 and 1042 only see relative linear movement and no relative rotational movement. Eventually, second retainer section 1300 will push first retainer section 1200 enough in the direction of arrow 1400 that second end 1220 will contact both first 400 and second 450 trunnion supports locking linearly in place these trunnion support elements with shoulder 116 of valve body 20 .
[0087] Disassembly of valve 20 can be performed by rotating second retainer section 1300 in a direction opposite of the rotational direction of arrow 1410 . During disassembly, second retainer section 1200 also is constrained from rotational movement by pins 1246 and 1246 ′.
Valve Components
[0088] Below various individual components of valve 10 will be reviewed.
[0089] FIG. 16 is a perspective view of valve body 20 taken from the first end 30 . FIG. 17 is a perspective view of valve body 20 taken from second end 40 . FIG. 18 is a side view of valve body 20 taken from the second end 40 . FIG. 19 is a sectional view of valve body 20 taken along the lines 19 - 19 . Valve body can include first end 30 and second end 40 . Flow passage 60 can proceed from first end 30 through second end 40 . Stem 500 can be rotatably connected to valve body 20 . Valve body 20 can include internal chamber 50 where valve ball 200 remains during use. From first end 30 to second end 40 , valve body 20 can include threaded area 140 , second cylindrical area 135 , second shoulder 134 , first cylindrical area 132 , first shoulder 130 , internal bore 50 , shoulder 116 , cylindrical area 112 , shoulder 110 , cylindrical area 102 , cylindrical bore 102 . First and second shoulders 100 , 110 are found in seat recess 120 . Bonnet recess 80 can be provided for allowing attachment of bonnet 800 to valve body 20 . One or more threaded bores 88 can be provided for fasteners 832 . Openings 834 , 834 ′ can be used for inserting a stop pin 836 . Lubrication port 160 and vent/bleeding port 162 can be respectively provided for lubrication fitting 161 and vent/bleeding fitting 163 .
[0090] FIGS. 29 through 34 show the components of the valve bonnet 800 and stem 700 assembly.
[0091] FIG. 32 is a perspective view of stem 500 . FIG. 33 is a side view of stem 500 . FIG. 34 is a sectional view of stem 500 taken along the lines 34 - 34 . Stem 500 can comprise shaft 510 , and ball drive element 520 . Ball drive element 520 can include substantially planar drive surface 530 . Circumferential bearing surface 550 can be included for rotatably connecting stem 500 with valve body 20 through stem receptacle 70 . Shaft 510 can include recess 580 for a key 582 which key can be used to operatively connect stem 500 to an actuator.
[0092] FIG. 29 is a perspective view of bonnet 800 . FIG. 30 is an end view of bonnet 800 . FIG. 31 is a sectional view of bonnet 800 taken along the lines 31 - 31 . Bonnet 800 can be used to prevent stem 500 from blowing out of valve body 20 . Bonnet 800 can be connected to valve body 20 through one or more fasteners 832 . Bonnet 800 can include tip 870 . Preferably, a seal is maintained between bonnet 800 and valve body 20 . To facilitate this seal, recess 860 can be provided which can include seal 862 such as an o-ring and back-up ring (the back up ring increasing the sealing pressure rating and resisting extrusion of the o-ring).
[0093] FIG. 20 is a perspective view of valve ball 200 . FIG. 21 is an end view of valve ball 200 . FIG. 22 is a sectional view of valve ball 200 taken along the lines 21 - 21 . Valve ball 200 can be spherically shaped and include top 210 , bottom 250 , and flow passage 270 . Upper spherical surface segment can be located by top 210 and lower spherical surface segment 310 can be located by bottom 250 . Stem recess 230 can be included.
[0094] Trunnion 220 can be located on top 210 and can include cylindrical area 222 . Cylindrical area 222 can be rotatably or pivotally connected to trunnion support element 400 . Bearing surface 224 can be substantially planar and slidingly contact first surface 402 of trunnion support element 400 . Preferably, a trunnion shim 404 is provided to act as a bearing surface between bearing area 224 of valve ball 200 and trunnion support element 400 . Also preferably, trunnion bearing 425 is provided between trunnion 220 and trunnion support element 400 . Also preferably, trunnion 220 is prevented from contacting valve body 20 to prevent wear.
[0095] Trunnion 260 can be located on bottom 250 and can include cylindrical area 262 . Cylindrical area 262 can be rotatably or pivotally connected to trunnion support element 450 . Bearing surface 264 can be substantially planar and slidingly contact first surface 452 of trunnion support element 450 . Preferably, a trunnion shim 454 is provided to act as a bearing surface between bearing area 264 of valve ball 200 and trunnion support element 450 . Also preferably, trunnion bearing 475 is provided between trunnion 260 and trunnion support element 450 . Also preferably, trunnion 260 is prevented from contacting valve body 20 to prevent wear.
[0096] Upper and lower spherical segments 300 , 310 can each be sealably connected to both seats 1000 , 1000 ′.
[0097] FIG. 23 is a perspective view of trunnion support element 400 shown in the valve of FIG. 1 . FIG. 24 is an end view of trunnion support element 400 . FIG. 25 is a sectional view of trunnion support element 400 , taken along the lines 25 - 25 . Trunnion support element 450 can be substantially similar to trunnion support element 400 and will not be described separately. Cylindrical opening 420 can be provided to slidably connect upper trunnion 220 of valve ball 200 . First and third sides 416 , 418 of trunnion support element 400 can be held in place between third shoulder 116 of valve body 20 and second end 1220 of first retainer section 1200 (limiting movement of trunnion support element 400 in the direction of arrows 1510 , 1520 ).
[0098] FIG. 26 is a perspective view of 1000 . FIG. 27 is an end view of seat 1000 . FIG. 28 is a sectional view of seat 1000 taken along the lines 28 - 28 . Seat 1000 ′ can be constructed substantially similar to seat 1000 (and seat 1000 ′ will not be individually described). Seat 1000 can include internal passage 1010 , first side 1020 , second side 1030 , along with first and second circumferential areas 1070 , 1080 . First and second circumferential areas 1070 , 1080 of seat 1000 sit respectively in first and second circumferential areas 1252 , 1262 of retainer 1200 . (For seat 1000 ′, first and second circumferential areas 1070 , 1080 sit respectively in cylindrical areas 112 , 102 of valve body 20 ).
[0099] Preferably, a seal is maintained between seat 1000 and valve body 20 (or second retainer section 1200 ). To facilitate this seal, recess 1040 can be provided which can include seal 1042 , which seal can each include an o-ring and back-up ring (the back up ring increasing the sealing pressure rating and resisting extrusion of the o-ring). Preferably, a seal is maintained between seat 1000 and valve ball 200 . To facilitate this seal, recess 1050 can be provided which can include seal 1052 , which seal 1052 seals with upper and lower spherical surfaces 300 , 310 of valve ball 200 (seat 1000 ′ is substantially the same). Seal 1052 can be installed in recess 1050 using any conventional means, such as crimping, adhesive, friction fit, or other means.
[0100] To facilitate sealing at lower line pressures between seats 1000 , 1000 ′ and valve ball 200 , biasing members 1090 , 1090 ′ can be provided which respectively push seat 1000 in the direction of arrow 1520 and seat 1000 ′ in the direction of arrow 1510 (both seats toward valve ball 200 ). At higher line pressures seats 1000 , 1000 ′ will tend to be pushed toward valve ball 200 because the larger exposed surface area on first side 1020 as opposed to second side 1030 . This is because line fluid will not be able to pass seal 1052 thereby limiting the amount of surface area to which the line fluid can assert pressure. In an alternative embodiment a second set of biasing members can be provided for second circumferential area 1080 (or area 1080 ′ for seat 1000 ′). In one embodiment, peripheral groove 1082 can be provided to reduce the amount of surface area of seat 1000 which contacts valve body 20 (or retainer 1200 for seat 1000 ′) thereby reducing frictional forces between these items.
[0101] In any of the embodiments a lip seal can be used as the sealing element. In any of the embodiments an extrusion ring can be used in combination with the lip seal.
[0102] The following is a list of reference numerals:
[0000]
LIST FOR REFERENCE NUMERALS
(Reference No.)
(Description)
10
compact manifold ball valve
20
body
30
first end
38
bores for fasteners
40
second end
42
raised area
44
peripheral groove for seal
46
seal
48
bores for fasteners
50
internal chamber
60
flow passage
70
stem receptacle
72
bore
80
bonnet recess
88
bores for fasteners
90
seat recess
100
first shoulder
102
cylindrical area
110
second shoulder
112
cylindrical area
116
third shoulder
118
cylindrical area
120
seat recess
130
first shoulder
132
cylindrical area
134
second shoulder
135
cylindrical area
138
third shoulder
139
cylindrical area
140
threaded area
150
internal bore
152
cylindrical area
160
lubrication port
161
lubrication fitting
162
vent/bleeding port
163
vent/bleeding fitting
180
opening
182
opening
200
valve ball
210
top
220
trunnion
222
cylindrical area
224
bearing area
230
recess for stem
250
bottom
260
trunnion
262
cylindrical area
264
bearing area
270
flow passage
280
first end
290
second end
300
spherical surface segment
310
spherical surface segment
400
first trunnion support element
402
first surface
404
trunnion bearing
405
trunnion shim/bearing
410
second surface
416
first side
417
second side
418
third side
419
fourth side
420
cylindrical opening
425
trunnion bearing
430
recessed area
450
second trunnion support element
452
first surface
454
trunnion bearing
455
trunnion shim/bearing
460
second surface
466
first side
467
second side
468
third side
469
fourth side
470
cylindrical opening
475
trunnion bearing
480
recessed area
500
stem
510
shaft
520
ball drive element
530
substantially planar drive surface
540
tip
550
bearing surface
552
bearing
570
top
580
recess for key
582
key
800
bonnet
810
first end
820
second end
830
plurality of recessed bores
832
plurality of fasteners
833
plurality of caps
834
opening for stop pin
836
stop pin
840
opening
850
recess
852
seal
860
recess
862
seal
870
tip
880
flat area
890
bore for stop pin
892
stop pin
894
grease bore
896
lubrication fitting
1000
seat
1010
internal passage
1020
first side
1022
planar surface
1030
second side
1032
shoulder
1040
recess
1042
seal and extrusion ring
1044
seal and extrusion ring
1052
seal or face seal
1090
circular wave spring
1100
two piece retainer
1200
first piece of retainer
1210
first end
1212
planar surface
1214
first recessed area
1220
second end
1222
planar surface
1224
seal recess
1226
seal
1230
internal passage
1242
first end
1244
second end
1246
plurality of shearable retainers to restrict rotation
1247
plurality of openings
1248
peripheral edge
1250
first shoulder
1252
first circumferential area
1260
second shoulder
1262
second circumferential area
1270
third shoulder
1272
third circumferential area
1300
second piece of retainer
1305
opening
1310
first end
1314
plurality of openings
1320
second end
1330
internal passage
1340
threaded area
1400
arrow
1410
arrow
1500
arrow
1510
arrow
1520
arrow
[0103] All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
[0104] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 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 set forth in the appended claims. The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
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A compact manifold ball valve having a valve body, valve ball, valve stem and two piece retainer system; the valve body including a valve chamber having first and second ends, and a first flow passage intersecting the valve chamber and valve ball. The valve ball can be trunnion supported and include pair of movable seat assemblies that can be used to seal the valve ball to the valve body. A two piece retainer can be used to hold in place the valve components, the two piece retainer including a first section which moves only linearly along with a second retainer piece that is a threaded ring that rotationally locks in place the first section of the two piece retainer. The two pieces of the retainer can be symmetrically located about the centerline of the flow passage of the valve body.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/349,620, filed on May 28, 2010.
TECHNICAL FIELD
[0002] The present disclosure is directed to methods and apparatus to control fluid flows from subsea wells. This disclosure teaches subsea methods and apparatuses that provide a redundant and contingency hydraulically sealed path from surface to subsea wells for well fluids, well tubulars, wire line, bits, logging tools, and other well tools during subsea drilling, subsea completing, and other subsea well operations that require well fluid control. More specifically, this invention teaches a multi path to enter subsea wells through fluid flow control systems of subsea wells. Furthermore, the invention teaches multiple marine riser conduits paths that have a common subsea wellhead entry path.
BACKGROUND OF THE INVENTION
[0003] When a well is drilled in a subsea environment the ability to repair, remove, or maintain the industry standard well control device, the Blow Out Preventer, BOP, is challenged due to the fact that it is on the seafloor. As mankind continues to drill wells in ever deeper water depths the BOP system may be miles below the sea surface.
[0004] The subsea BOP currently used by the industry is further compromised or challenged by the large riser pipe that can be several feet in diameter, miles long, and have a weight of millions of pounds being mounted on top of the BOP stack and proceeding to the surface. This large riser is used to allow return fluids from drilling the well to flow from the subsea well head to the surface through the BOP If the riser pipe fails then there is no path to get drill pipe or kill fluids into the subsea well. If the riser pipe fails, and the B.O.P.s fail during a blow out, like it did in the 2010 Gulf of Mexico blowout, then there is no method to get drill pipe into the well and kill the well with heavy fluid to stop the fluid from erupting from the well. Embodiments of this invention are methods and apparatus to avoid failed risers and BOPs by constructing an alternative path to the subsea well that is not encumbered by the previously failed BOP, failed risers, or foreign debris lodged in the BOP
[0005] The current industry methods teach towards making the subsea BOP system reliable by stacking in a plurality of closure devices all in the same axis in a BOP stack, and to continually test the BOPs. However, if the BOP fails during a blow out, for example foreign object and debris like a large piece of earth or previously disposed casing or wellhead are pushed up into the BOP the BOP will not close and the foreign debris that is lodged in the BOP can also prevent the entry of fluid or drill pipe from surface to enter in the well to control the blowout. What is needed is an alternative path to the subsea well from surface that is unencumbered by the primary path. What is further needed is a method that presents an alternative path through drilling risers, and subsea BOPs and that allows a parallel subsea BOP stack and riser to be offset from the primary path and the first flow path axis of subsea BOPs and riser to a subsea well.
[0006] The current subsea industry is further challenged by the need to drill in ever deeper water depths and ever deeper subterranean depths below the subsea floor. A problem presents itself in deep water depths where the force that the sea depth places on the earth is less than the force that the overburden of the earth would places on subterranean formations. This results in the subterranean rock hydraulic fracture pressure of deep water offshore wells being lower than deep wells drilled from land. The drilling fluid hydrostatic pressure of the deep water wells weighted drilling fluid has a down hole hydrostatic pressure increased by the vertical height of the subsea wells seafloor depth to the surface of the sea. What is needed is a means to have the drilling mud from the sea floor, to the bottom of the well where the drill bit is cutting at a higher density, and the density of the drilling fluid between the outer diameter of the drill pipe and the internal diameter of the riser from the sea floor to the surface to have a lighter density. Embodiments of the invention allow for such a dual gradient drilling fluid means to be achieved by pumping through a second BOP conduit a lighter fluid and mixing it below the B.O.Ps to create a lighter fluid hydrostatic from the seafloor to the surface in the drilling riser. This then allows wells to be drilled safer as the risk of lost circulation due to hydraulic fracturing of the subterranean rocks due to the combination of hydrostatic forces developed by heavy drilling fluids and drilling cuttings in the casing and open hole in addition to the hydrostatic forces of the drilling fluids and cuttings on the outer diameter of the drill pipe and the internal diameter of the drilling riser has been reduced.
BRIEF SUMMARY OF THE INVENTION
[0007] Various embodiments of the invention include new well construction methods and procedures and apparatus to assure that subsea wells can be drilled with redundant subsea flow control systems making subsea drilling safer and less likely to cause massive contamination to the oceans and seas of the world.
[0008] In one embodiments of the invention there is a new method of well construction that results in a redundant and separate well control path for drill pipe, wire line, and fluid injection to bypass damaged risers and subsea blow out preventers.
[0009] Various embodiments of the invention include methods and apparatus that will allow man to more safely produce subsea hydrocarbons using a redundant path riser and subsea BOP method.
[0010] In yet another embodiment, a method is taught where a dual gradient drilling fluid system can be achieved where the fluid gradient in the drill pipe outer diameter in the drilling riser is lower than the fluid gradient in the casing and well bore below the sea floor thusly allowing subsea wells to be drilled with less risk of hydraulically fracturing the subterranean rock, losing drilling fluid, subsequently losing the hydrostatic force to control the fluid from the well and resulting in a blowout. This method of lightening the fluid hydrostatic in the riser can also be used in the art of primary cementing a casing in a subsea well thereby also reducing the down hole hydrostatic forces on the subterranean well bore during cement placement and cement cure time. This lightening method is achieved by having at least two separate fluid and drill pipe flow paths from surface to the subsea wellhead each having subsea BOP systems with different risers but a common mixing point below the respective risers B.O.Ps and injecting a lighter fluid down one flow path and taking returns of drilling fluids, cuttings, or cement, and lighter fluid up a riser. In an embodiment of the invention, the multi-path apparatus comprises at least two separate continuous paths to the surface.
[0011] In one embodiment of the invention there is a method for the construction of a subsea well comprising connecting the distal end of a subsea multi-path apparatus to the subsea well wherein the subsea multi-path apparatus comprises at least two separate paths each comprising separate proximal ends converging to the common distal end of the subsea well; connecting at least one subsea closure apparatus to a proximal end of the subsea multipath apparatus; connecting a distal end of a riser conduit apparatus to the subsea closure apparatus wherein the riser has the proximal end at or near the surface of the sea: and hydraulically sealing all connections of the subsea wellhead, subsea multipath apparatus, subsea closure apparatus, and riser forming a continuous sealed hydraulic conduit from surface to the subsea wellhead. The subsea closure apparatus may additionally comprise a blow out preventer system. In a specific embodiment of the invention, the subsea multipath apparatus is deployed to the subsea well before the subsea closure apparatus. Additionally, the riser conduit apparatus may comprise a drilling riser apparatus. The method may further comprise the step of deploying a pipe from a rig at the surface through the continuous sealed hydraulic conduit into the subsea well. A second multi-path apparatus may be connected to a proximal end of the subsea multi-path apparatus, forming two attached multi-path apparatus.
[0012] Other embodiments of the invention is a method of controlling the fluid flow from a subsea well comprising connecting at least two separate subsea blowout apparatus to different proximal end branches of a subsea multi-path apparatus comprising at least two proximal ends converging to a common distal end; connecting to the respective proximal end of at least one of the at least two separate subsea blowout apparatus to at least one riser conduit wherein the riser conduit has a proximal end at the surface; inserting at least one continuous injection conduit having a proximal end at the surface into at least one of the riser conduit; pumping fluids from the surface of into the subsea well through at the least one continuous conduit having a proximal end at the surface. In a specific embodiment of the invention different fluids are injected down at least two separate injection conduits inserted in at least two separate riser conduits through separate subsea blowout apparatus with the pumping from surface of the fluids. In certain cases, a lighter fluid is pumped down the a separate injection fluid conduit mixed at the discharge distal end of the multi-path apparatus with fluids coming from the well.
[0013] The embodiment above may also include attaching a drill bit and down hole assembly to the continuous conduit; deploying the continuous conduit through the subsea blow out preventer and the multi-passage apparatus; setting the drill assembly and weight of continuous conduit down in the well; rotating the drilling assembly and cutting earth; pumping a drilling fluid through the continuous conduit and the drilling assembly; returning the drilling fluid with earth cuttings to the surface through the multi-path assembly, blow out preventer, and riser conduit; mixing and returning the second fluid with the first fluid and earth cuttings up the riser conduit to surface. In a specific embodiment of the invention, the second fluid has a lower fluid density than the first fluid. The second fluid may also have a higher viscosity than the first fluid.
[0014] An additional embodiment of the invention is a multipath subsea apparatus comprising a subsea spool containing at least two proximal ends where the at least two proximal ends intersect forming a common exit pathway at or above the distal end of the subsea multipath apparatus. The apparatus may further comprise mechanical connector means on the proximal and distal ends adapted to form hydraulic seals with connected devices and apparatus. Additionally, hydraulic seals may be formed using elastomeric or metal to metal seals. The multipath subsea apparatus may also comprises at least one subsea closure device, such as a gate valve. A specific embodiment of the invention further comprises a blow out preventer that may be located on any one or more of the proximal ends of the apparatus. The apparatus may further comprise a riser conduit connector and release apparatus attached to at least one of the proximal ends of the subsea multipath apparatus.
[0015] Another embodiment of the invention is a multiple access subsea system comprising a subsea spool containing at least two proximal ends where the at least two proximal ends intersect forming a common exit pathway at or above the distal end of the subsea multipath apparatus. The system may further comprise mechanical connector means on the proximal and distal ends which form hydraulic seals with connected devices and apparatus. Additionally, hydraulic seals may be formed using elastomeric or metal to metal seals. The system may also comprises at least one subsea closure device, such as a gate valve. A specific embodiment of the invention further comprises a blow out preventer that may be located on any one or more of the proximal ends of the apparatus. The system may further comprise a riser conduit connector and release apparatus attached to at least one of the proximal ends of the subsea multipath apparatus. The system may also form a hydraulic seal from the surface down to the subsea well.
[0016] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates a subsea well with a damaged marine riser blowing out fluids whilst this inventions redundant well control system is allows a secondary Blow Out Preventer, BOP and marine riser to deploy tubing into the subsea well to control and stop the blow out.
[0018] FIG. 2 illustrates this inventions subsea wellhead spool piece having a plurality of proximal entry paths with a common distal exit path.
[0019] FIG. 3 shows a general configuration of this inventions subsea redundant path BOP deployed to allow dual gradient drilling where a heavy drilling fluid is pumped through a drill pipe and the fluid is mixed with a lighter second fluid below the BOPs and lifted to surface through a marine riser.
DETAILED DESCRIPTION OF THE INVENTION
[0020] As used herein, “a” or “an” means one or more. Unless otherwise indicated, the singular contains the plural and the plural contains the singular. Where the disclosure refers to “perforations” it should be understood to mean “one or more perforations”.
[0021] As used herein, “surface” refers to locations at or above the surface of body of waters surface. The body of water can be a sea, ocean, lake, or ice body.
[0022] As used herein, “proximal” refers to the position closer to the surface of the sea.
[0023] As used herein, “distal” refers to a position that is in the opposite direction of the proximal position.
[0024] As used herein, “spool” refers to a structural body of a well having connection positions on the distal end and the proximal end and comprising at least one passage through said body.
[0025] As used herein, a “Blow Out Preventer” stack or BOP refers to devices used to control the fluid flow from wells. BOP systems encompasses many configurations and arrangements of closure devices including but not limited to annular bags, shear rams, pipe rams, and various hydraulic and electrical devices used to actuate and control the B.O.P stack.
[0026] As used herein, a “back pressure valve” refers to a device that allows fluid to flow in only one direction. This device when placed in a well casing is sometimes known in the oil and gas grouting and cementing business as a float collar or float shore, wherein said back pressure valve is inserted into a piece of casing having, normally fixed with a cured cement grout, having threads on either end of said casing and the inserted into and near the bottom of a well casing string as it is deployed in a well such that fluids can be pumed down the casing but fluids from outside the casing cannot flow into the casing.
[0027] As used herein “connected” includes physical, whether direct or indirect, permanently affixed or adjustably mounted connections. Thus, unless specified, “connected” is intended to embrace any operationally functional connection.
[0028] Referring to FIG. 1 , presents a subsea well system that has had a subsea blow out. FIG. 1 further presents a novel new multipath apparatus 109 being predisposed on a subsea well head 104 being at the seafloor 103 . Well casing 110 is shown being below the sea floor 103 and proceeds to subterranean depths where reservoir fluids are erupting upward though the failed BOP 101 . The subsea well system in FIG. 1 shows a failure of the marine riser 102 , which is shown in FIG. 1 as having fallen down from its normal surface proximal termination point on a drilling rig down into the sea. The first drilling Blow Out Preventer, BOP stack, 101 has failed to close in the subsea well fluid flows.
[0029] A BOP may have many combinations of various closure apparatus designed to stop fluid flow from wells such as annular bags, pipe rams, and shear rams and in subsea applications they are deployed with various connectors, actuators, and controllers. Due to the difficulty of the environment of subsea wells and the great risk to the environment the current practices is to deploy a plurality of these closure devices subsea such that they form a stack formed by connecting one upon the other for redundancy. The current industry teaches toward stacking these closure devices in combinations, one on top of the other, in various sequences. FIG. 1 depicts a new method of constructing a completely independent path to the wellhead 104 that avoids the damage of BOP 101 and riser 102 . Furthermore, this invention method teaches deploying a second BOP system 106 with a riser 107 connected to the multipath apparatus 109 and disposing a drill pipe 105 through the riser 107 , BOP 106 , multipath apparatus 109 , wellhead 104 and into the well. The drill pipe 105 then allows the pumping of a fluid from the surface form a drilling rig or service supply vessel into the well killing the well blow out by the addition of this fluids hydrostatic weight.
[0030] This failure of the BOP 101 shown in FIG. 1 can be caused by a variety of reasons, including but not limited to mechanical failure, electrical failure, hydraulic failure of the various devices in the BOP 101 system, failure in human procedures to construct the BOP 101 , poor maintenance of BOP 101 , and a previous casing disposed in the well moving up through the BOP 101 , resulting in fluid flowing up the well casing 110 through the wellhead 104 . In all the failure modes the result is that the BOP 101 does not have the ability to close in the well fluid flows. This embodiment allows the blow out well to be killed as the method teaches to predispose a multipath apparatus 109 on subsea wellhead 104 .
[0031] The failure of the riser 102 depicted in FIG. 1 can be caused by a variety of reasons, including but not limited to mechanical failures, ocean currents, storms, failure of riser latching systems, and human error. A method taught herein of predisposing at least one multipath apparatus for drill pipe 105 to be deployed below the damaged BOPs 101 and damaged riser 102 . This redundant path from the surface through riser 107 BOP 106 and a multipath apparatus 109 to the wellhead 104 avoids obstructions of riser 102 or BOP 101 , allows removal of any obstruction, allows the milling out of obstructions, and allows the pumping of fluids through a functional and redundant BOP 106 in the well. The proximal end 108 of the multipath apparatus is attached to the BOP and the well head through hydraulic seals such as elastomeric and/or metal to metal seals. Using hydraulic seals in connections between the wellhead and the riser at the surface creates a fluid tight connection protecting the outside environment from fluid leakages whilst also building a passage for conduits, fluids, wireline, from the surface into the subsea well.
[0032] Referring to FIG. 2 , a new subsea apparatus is depicted and referred to herein as a multipath apparatus that has at least two entry paths 203 at the proximal end having a common exit path at the distal end 204 . The invention teaches to predispose the multipath apparatus 202 on a subsea well head. The apparatus 202 can be connected to the wellhead directly or to a wellhead hydraulic connector apparatus disposed on top of the wellhead. In either case the method of predisposing the multipath apparatus 202 prior to disposing BOP stacks is a new construction method thereby providing a heretofore never know redundant path BOP system to the wellhead. The method then teaches to connect the multipath apparatus 202 shown in FIG. 2 on the distal end to a wellhead and the proximal ends 203 to subsea BOP systems and the distal ends of these BOP systems to riser that have their proximal end at the surface. Redundant BOPs and redundant risers can be connected in advance of a blow out and failure of the primary BOPs and riser, or can be deployed after a blow out and failure of the primary BOP and riser system using known rig and remote operated submersible vehicle methods. However, the multipath apparatus is predisposing prior to any BOP system on to the subsea wellhead system.
[0033] Referring FIG. 2 , the new subsea multipath apparatus 202 has at least two branches 201 that have an internal diameter sufficient to allow the passage of drill pipe, drill pipe down hole assemblies like drilling motors, drill collars, drilling bits, a various directional tools.
[0034] FIG. 2 depicts a multipath apparatus having three proximal entry ports 203 . It is clear that the multipath apparatus can have many multipath apparatus ports and resulting branches 201 .
[0035] FIG. 3 illustrates another embodiment of the invention. FIG. 3 , depicts subsea well penetrating the seafloor 301 having more than one subsea multipath apparatus 302 and 310 . Apparatus 302 has a subsea gate valve 309 to allow for it to be opened and closed. Those familiar with the art of subsea operations may well want to include a plurality of valves like 309 and the valves can be operated by many means known to those familiar with the art of subsea drilling including remotely operated vehicles. FIG. 3 presents a method of changing the fluid characteristics of the returning well fluids by mixing fluid 1 pumped from the surface down drill pipe 303 disposed in riser 305 with fluid 2 being pumped down a second fluid conduit deployed from surface inside riser 308 . The hydrostatic force of the fluid column in the well casing 307 can be reduced by pumping fluid 2 that has a lower density than fluid 1 , and mixing the two fluids in the subsea multipath apparatus 302 and allowing the mixed fluids to rise through the BOP 306 through the riser 305 to surface. The BOP 304 can close the annulus fluid path between the conduit inside of it and riser 308 , thereby forcing the lighter fluid 2 to mix with the well fluid 1 being pumped from surface down the drill pipe 303 and the combined fluids flow up to surface through BOP 306 through the riser 305 .
[0036] Referring to FIG. 3 the viscosity and hence the riser fluid's ability to carry solids and earth cuttings to the surface can be enhanced by injecting a viscosifying fluid as the second fluid down the continuous conduit 311 deployed from surface through riser 308 and mixing in the subsea multipath apparatus 310 with the first fluid coming from the well wherein the first fluid is being pumped from surface through drill pipe 303 and the mixed fluids rising through riser 305 . The ability to improve the fluid viscosity of the mixed fluid in riser 305 formed in the subsea multipath apparatus 310 allows for lower viscosity fluids to be pumped from surface down drill pipe 303 which reduces the surface friction pressure for the surface pumps, as the velocity and hence fluid capacity to carry cuttings from the well is higher is often times higher in the well casing 307 by drill pipe 303 annulus than it is in the riser 305 .
[0037] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, subsea deployment means, subsea control systems, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skilled in the art will readily appreciate from the disclosure of the present invention, processes, devices, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, devices, manufacture, compositions of matter, means, methods, or steps.
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The present invention is directed to methods and apparatus to construct subsea wells with redundant parallel fluid flow control systems to allow new methods to stop subsea blow outs. More specifically, this invention provides methods and apparatus to construct subsea wells with a plurality of redundant parallel paths allowing for the first time drill pipe and other intervention conduits, wire line, and fluids to be deployed below a damaged drilling riser and or a damaged blow out preventer through a separate blow out preventer and riser system presented in this invention.
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BACKGROUND OF THE INVENTION
The present invention relates to a plate filter having horizontally arranged filter plates for extracting liquid from a slurry while forming the solid constituents into a filter cake.
In a filter of this type, the filter plates can be pressed toward one another by a locking device and an endless filter band passes between the plates and is guided on rollers, each filter plate being provided with a watertight partition which is provided with channels for guiding the liquid and has a frame-type raised portion along its edges which extends toward both sides of the plate and serves as a sealing surface.
German Pat. No. 1,461,500 discloses a plate filter of the above-mentioned type. In this plate filter, the filter chamber is formed by two adjacent filter plates, the frame-type raised portion being larger toward one side of the partition than toward the other so that every filter plate has the shape of a flat, downwardly open bowl.
It has now been found that for a number of particular fields of use, particularly in cases where the resulting filter cake must be rinsed before the filtering process is completed, the consumption of rinse water can be reduced only by increasing the cake thickness. However, the necessary corresponding increase in the depth of the chamber in the known press is possible only within limits since the drop in efficiency of a plate filter is more than proportional to the increase in the chamber depth.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to modify such a known plate filter so that larger cake thicknesses can be handled without decreasing the filter efficiency.
This and other objects according to the present invention are achieved by providing the filter plates with channels on both sides of the plates, disposing a frame between each two adjacent filter plates and arranging the filter cloth to pass directly by the upper and underside of a filter plate and between a filter plate and an associated frame. With this arrangement, a filter chamber is produced between two filter plates from which the fluid i.e. the filtrate can be pushed through filter cloth at both sides, meanwhile the solids of the slurry remain and accumulate to a cake in the filter chamber. The placing of a frame between two adjacent filter plates further offers the possibility of optimally setting the depth of the filter chambers in an available filter press, depending on the product to be filtered, by the use of frames of different heights.
In embodiments of the present invention, a suspension device is provided to connect the filter plates and the frames to one another, the members of the suspension device being dimensioned so that when the plate filters are open, the distance between the underside of a filter plate and the frame therebelow is less than the distance between the upper side of a filter plate and the frame thereabove. This arrangement assures that the cake formed during the filtering and pressing operation can be safely removed without the opening or closing path for the entire filter arrangement becoming inappropriately large.
According to a further embodiment of the present invention, an additional advantage is provided by having the distance between the upper side of the filter plate and the frame thereabove correspond at least to the height of the frame. Since the space between the underside of the filter plate and the frame therebelow need only be large enough so that the filter cloth, when the press is open, can be pulled through without affecting the filter cloth drive, this will produce an advantageous limitation in the structural size of the filter press.
In an advantageous embodiment of the invention, the opening of each frame is designed to widen in the direction toward the filter plate disposed therebelow. Thus, when the plate filter is opened, the upper filter plate can safely be lifted together with the frame away from the filter cake therebelow.
In a further advantageous embodiment of the invention, the frame is provided with at least one slurry inlet opening. By placing the slurry inlet for the respective filter chamber in the associated frame, there results a particularly favorable inflow of slurry, as well as a substantial structural simplification of the associated filter plates, because the latter need only be provided with inlet and outlet channels for the rinse water, the filtrate and possibly air. Furthermore, it is possible with relatively simple structures to increase the number of inlet openings without having to change the associated filter plates.
According to a further embodiment of the invention, the filter plates are each in communication with inlet lines for the rinsing liquid and for the blowing-in of air through the space formed by the channels in the underside of the plates. With this arrangement it is advantageously possible, once the filtrate has been removed from both sides of the respective filter chamber, to introduce the rinse water and possibly air for blowing dry the filter cake from but one side so that the filter cake can be rinsed out in a particularly effective manner.
According to a further embodiment of the invention, link chains are provided as the suspension device and each link is provided with a bore at one end and a longitudinal hole at the other end, the chain also being composed of connecting bolts formed by supporting journals which are connected with the filter plates. Each link is additionally provided with a recess for accommodating a holding pin connected with a frame. With this particularly advantageous configuration of the plate filter according to the invention, the locking and opening process can be effected in a simple manner in spite of the greater number of elements resulting from the additionally provided frames, and the greater weight. It is particularly advantageous that the same distance can be set for all elements during opening and that, from the standpoint of stability, the individual filter plates need be designed only on the basis of their own weight while the weight of the filter plates is fully supported by the link chains and from there by the machine frame.
In accordance with a further feature of the invention, the recess for the holding pin of each frame is disposed below the bore in the associated link and its dimensions are greater than the diameter of the holding pin. This permits easy removal of the filter plate from the frame therebelow so that the filter cloth can be freely pulled through when the press is open.
According to a particularly advantageous feature, each frame is suspended via separate supporting slips from the supporting journals of the filter plate disposed thereabove, longitudinal holes being provided for the holding pins of the frame and the openings of these holes being adapted to the distance between the filter plate underside and the frame. This arrangement has the advantage that, during the closing and opening process, the frame can place itself against the sealing surfaces of the two adjacent filter surfaces since it is held by the filter plate thereabove in a manner independent of the links of the suspending device without any adverse influences from the links of the suspending device during the closing process.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view of an embodiment of a plate filter according to the invention.
FIG. 2 is a side view, to an enlarged scale and partly in cross section, of the suspension device, with filter plates and frames, of the embodiment of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The filter press apparatus shown in FIG. 1 is composed of a machine frame 1 which accommodates a plurality of superposed filter plates 2. A plurality of guide rollers 3 extends along one side of the filter plate array, while a similar plurality of guide rollers 4 extends along the opposite side thereof. A respective roller 3 is located adjacent one edge of each plate 2 and a respective roller 4 is located adjacent the opposite edge of each plate 2. An endless filter cloth 5 is brought around rollers 3 and 4, passing alternatingly around a roller 3 and a roller 4, so that a respective reach of cloth 5 passes adjacent each face of each plate 2.
At the upper end of the filter arrangement, the filter cloth passes through a schematically indicated tensioning station 6, and in the lower region the cloth passes through a drive station 7. Below the drive station there is disposed a rinsing device 8 provided with nozzles 9 from which the filter cloth can be charged with rinsing water. The movement of the filter cloth takes place in the direction of arrow 10.
The lowermost filter plate is disposed on a lifting table 11 which is connected with a locking device 12 in the form of a hydraulic cylinder, for example.
Between every two adjacent filter plates 2 there is provided a frame 13. When the plate filter is closed, each frame 13 forms a filter chamber in cooperation with the filter plate disposed thereabove and the filter plate disposed therebelow. The individual filter plates and the frames disposed therebetween are suspended from a yoke plate 15 which is supported by vertical supports 14. The filter plates and frames are suspended from plate 15 by a suspension device shown in detail in FIG. 2 but hidden in FIG. 1 by the two supports 14.
The filter plates 2 are provided, according to the present invention, with channels at both sides thereof. Accordingly, the filter cloth is guided so that it passes directly by both sides of each filter plate, a fact which must be taken into account in the design and arrangement of guide rollers 3 and 4.
FIG. 2 shows details of the filter plate, the frame and the suspension device of the apparatus of FIG. 1. As appears at the portion in cross section of the middle plate-frame arrangement, the filter plates 2 according to the invention are provided with channels 16 at both faces. These channels in each surface of a plate are composed of a plurality of parallel arranged grooves which extend parallel to the plane of the drawing and which open at their ends into a collecting trough 17 extending transversely to the direction of the grooves. The filter plates are connected with inlet lines for rinse water and air (not shown in detail) and with extraction devices for the resulting filtrate coming from the area formed by the channels. As shown by the channel 18 (in dashed lines) which opens into the area of the lower channels of plate 2, rinse water and blown-in air are forced into the filter chamber therebelow and then extracted from filter plate 2' by means of filtrate extraction devices.
As further shown in the cross-sectional portion, frames 13 are designed so that their opening widens toward the bottom, thus assuring dependable removal of the filter cake. The degree of widening must be adapted to the particular product to be filtered. In the case of sticky products the opening angle must be greater than that shown in the drawing.
FIG. 2 depicts the filter in its open state in order to more clearly show the suspension device. This device includes for example, a total of four link chains, two at the front of the apparatus and two at the rear. FIG. 2 shows part of one such chain, the links 19 of which are each provided with a bore 20 at one end and an elongated slot 21 at the other end. The bore 20 at the top is connected with the slot 21 of the link thereabove by a journal pin 22 which is fastened to the associated filter plate 2. In the open state of the filter, every filter plate is thus suspended from the link chain without the weight of a filter plate being imposed on the filter plates thereabove. The total weight of the filter plates is supported by the four link chains and the yoke plate.
When the plate filter is closed, the plates and frames lay themselves one on top of the other, beginning at the bottom of the filter, and the journal pins 22 move upwardly in the slots 21 so that the respective links 19 are pivoted to a certain extent. The links shown in FIG. 2 would, for example, be pivoted clockwise about pins 22.
In order to eliminate any influence of the pivoting of the links during closing of the plate filter on the fastening of the frames to the suspension device, additional suspension clips 23 are provided. One end of each clip 23 is held by a supporting journal pin 22 and the other end thereof is provided with a bore or an elongated opening 24 into which a holding pin 25 of the respective frame 13 engages. Thus the frame can safely rest on the filter plate therebelow during the closing process independent of the suspension device.
The introduction of the substance to be filtered and the removal of filtrate is effected in the conventional manner through inlet and outlet channels which are formed in the filter plates and frames by suitable flush bores as indicated in FIG. 1 by conduits 26 for the slurry inlet. Corresponding channels (not shown) are provided for the discharge of filtrate and/or rinse water. A particular advantage of the present invention is that separate discharge channels are provided for the filter surfaces disposed above a frame and for those disposed below a frame. If these channels are made blockable, it is possible to initially remove the clear filtrate through both channels and then the rinse filtrate only through the channel associated with the filter surface disposed below a frame, the other channel being blocked.
The flush bores form a continuous channel in the closed state of the filter press and connecting channels branch off therefrom, these connecting channels including filtrate discharge channels leading to the filter plates or slurry inlet channels leading to the individual frames. Whereas in the prior art plate filters, the inlet and outlet channels for the slurry and the filtrate exclusively enter into the filter plates, the present invention provides the advantage that the slurry can enter through simple bores 27 in the frames into the filter chambers which are each formed by two filter plates and an interposed frame.
The conduit 26 is formed by a lateral projection at the outer side of each filter plate 2 and frame 13 respectively. A downward projecting conical elongation of each of the holes forming the conduit, inserting into a corresponding recess of the next hole below when closing the plate filter ensures that liquid cannot escape from the conduit when the plate filter opens.
At least two conduits are arranged in this manner at opposite sides of the plate filter, whereby one conduit serves as inlet-and distribution conduit for the slurry (as shown in FIG. 1) and the other conduit (not shown) serves as collecting-and outlet conduit for the filtrate, rinsing fluid etc. and in the same way by simple bores (not shown) in each filter plate with trough 17.
Rinsing fluid and air are supplied in a known manner to each filter plate by individual, partly flexible tubes (not shown in FIG. 1). The blocking of the channels, conduits or tubes resp. is effected by valves in a known manner.
If the arrangement of guide rollers 3, 4 shown in FIG. 1 is reversed, i.e. rollers 4 with the larger diameter are disposed above the rinsing device, this provides the additional possibility of using larger filter plates and thus of increasing the filter surface.
It will be understood that the above description of the present invention is susceptible to various modifications, changes and modifications, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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A plate filter composed of horizontal filter plates arranged in a vertical stack and each defining a fluid-tight partition and being provided with fluid flow channels at both its upper and lower faces, a plurality of frame members each disposed between a respective adjacent pair of filter plates, a pressing unit arranged to press the filter plates and frame members toward one another in a direction to close the filter, cloth guided by rollers to traverse a path extending past each face of each filter plate in the region between each such face and the frame member adjacent thereto, and a suspension arrangement composed of a chain of links supporting the filter plates and the frame members when the filter is open.
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This is a continuation of application Ser. No. 08/288,131 filed Aug. 8, 1994 which is a continuation of application Ser. No. 08/083,427 filed Jun. 28, 1993, now abandoned.
FIELD OF THE INVENTION
This invention relates to integrated circuits and more particularly to substrate bias circuits.
BACKGROUND OF THE INVENTION
Present complementary metal oxide semiconductor (CMOS) dynamic random access memory (DRAM) circuits are frequently used for main memory in a variety of applications including laptop and notebook computer systems which are battery powered. These battery powered applications impose practical limitations such as speed, power, and feature size on dynamic random access memory design. Optimal performance of a system depends on an effective balance of these factors in the design.
The trend in dynamic random access memory design is to minimize power consumption, as operating frequency increases, by the reduction of capacitance and operating voltage. Reduction of circuit feature sizes effectively reduces the length of leads, the surface area of diffusions, and the space between diffusions. Shorter lead lengths and smaller diffused areas advantageously reduce circuit capacitance. Less space between diffused regions, however, may have the undesirable effect of creating parasitic leakage paths between adjacent diffusions due to a phenomenon known as the short channel effect. This phenomenon results in a reduction in the threshold voltage of parasitic field effect transistors formed between closely spaced diffused regions and in an increase in leakage current. One method of increasing the isolation or threshold voltage of the parasitic field effect transistors is to increase the bulk or substrate impurity surface concentration. Such an increase in the substrate impurity surface concentration is limited by the consequent undesirable increase in junction capacitance.
On-chip substrate bias generators for dynamic random access memories have become a standard practice in the industry because they reduce junction capacitance between diffused regions and the substrate. Typically a negative bias with respect to ground is applied to a P-type substrate by the on-chip substrate bias generator. This negative substrate bias V BB increases the reverse bias of all junctions formed between N-type diffusions and the P-type substrate. Junction capacitance decreases because it is inversely proportional to the square root of the reverse bias across the junction. For a dynamic random access memory, bitline junction capacitance is a major component of active power consumption that must be charged and discharged during active operation. This active power consumption is determined by the product of capacitance, the square of the operating voltage, and the operating frequency. Thus, a significant reduction in active power consumption is achieved because bitline junction capacitance dominates the total circuit capacitance of the dynamic random access memory.
A reduction in leakage current or improved isolation between closely spaced diffused regions is achieved by the application of negative bias V BB to a P-type substrate with respect to ground or reference supply V SS . The result of the negative bias is to increase the bulk to source potential of all N-channel transistors, including parasitic transistors, in common with the substrate. This increases the N-channel transistor threshold voltage by a phenomenon known as body effect, thereby decreasing leakage between the closely spaced diffused regions. Thus, the substrate bias V BB must be closely regulated over a variety of operating conditions, or large variations in speed and power of the dynamic random access memory will result from variations in N-channel transistor threshold voltage and junction capacitance.
Substrate bias regulation must comprehend large differences in substrate current during high-power active operation as well as low-power standby operation. In, U.S. Pat. No. 4,430,581, entitled SEMICONDUCTOR SUBSTRATE BIAS CIRCUIT, Jun-ichi Mogi et al use two substrate bias circuits. One of their bias circuits is always enabled and pumps substrate current at a constant frequency that is sufficient to compensate for junction leakage. The other bias circuit is enabled only during the active operation. It pumps substrate current at a frequency that is proportional to the dynamic random access memory operating frequency.
There are two notable issues with respect to the teaching of Mogi et al. First, the constant frequency bias circuit remains enabled when the variable frequency bias circuit is enabled. The variable frequency bias circuit is designed to operate in the dynamic random access memory active cycle and can pump much more current than the constant frequency bias circuit. Operating alone, the variable frequency bias circuit is sufficient to maintain a stable substrate bias level for current produced by both active operation and by junction leakage. Thus, the oscillator and pump circuit of the constant frequency bias circuit needlessly expend power during the active cycle. Second, the teaching of Mogi et al fails to satisfy some modes of operation which produce more substrate current than that which can be pumped by the active cycle bias circuit. Among these modes of operation are burn-in, where more substrate current is produced by high operating voltage, and parallel test, where more substrate current is produced by additional active arrays.
SUMMARY OF THE INVENTION
These issues are resolved by a circuit for generating a bias for a semiconductor device. A control circuit activates only one of a plurality of enable signals at any time. Each of a plurality of bias circuits is responsive directly to a different enable signal from the control circuit. At any time, only one of the bias circuits is enabled by an active enable signal from the control circuit. The enabled bias circuit controls the bias applied to a common bias terminal connected to the outputs of each of the bias circuits.
The present invention provides a stable substrate reference potential for a variety of operating modes. Power is conserved over previous methods by enabling only one bias circuit for any operational mode. A further improvement incorporates an on-demand bias circuit that is enabled whenever substrate bias exceeds predetermined limits during special operating modes such as burn-in or parallel test.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the invention may be gained by reading the subsequent detailed description with reference to the drawings wherein:
FIG. 1 is block diagram of a substrate bias circuit;
FIG. 2 is a truth table relating to a control circuit included within FIG. 1;
FIG. 3 is an oscillator circuit which may be used in bias circuits of FIG. 1;
FIG. 4 is a pump circuit which may be used in bias circuits of FIG. 1;
FIG. 5 is a block diagram of an embodiment of the high power bias circuit of FIG. 1 .
FIG. 6 is a block diagram of another embodiment of the high power bias circuit of FIG. 1 .
FIG. 7 is a level detector circuit which may be used in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, the substrate bias circuit will be described in detail. Substrate bias circuit 10 has two input terminals 7 and 8 respectively, for receiving burn-in enable signal BINEN and row logic signal RL 1 _ and a common bias terminal 19 . Common bias terminal 19 is connected to the substrate 21 of a semiconductor device. The burn-in enable signal BINEN is active to enable appropriate circuits during a burn-in operation. Row logic signal RL 1 _ is a clock signal that is derived from a row address strobe signal (RAS_) which has a repetition rate corresponding to the operating frequency of the dynamic random access memory. Shallow substrate bias signal VBBS is developed by level detector 20 and indicates the presence of a shallow substrate bias V BB . The burn-in enable signal BINEN, row logic signal RL 1 _, and shallow substrate bias signal VBBS are inputs to control circuit 12 . Generally, any combination of these inputs will cause control circuit 12 to activate only one of a number N of enable signals corresponding to the number N of bias circuits. Here, where the number N is equal to three, a combination of these inputs will cause only one of the following number N of enable signals: (a) enable high signal ENH, (b) enable boost signal ENB, or (c) enable low signal ENL to become active at a time. The enable signals, produced by control circuit 12 , are applied to enable terminals 13 , 15 , and 17 , respectively, of three substrate bias circuits 14 , 16 , and 18 so that only one of the three bias circuits is enabled at a time. The output terminal of each bias circuit 14 , 16 , and 18 is connected to the common bias terminal 19 . The active, or enabled, bias circuit establishes a substrate bias V BB on substrate 21 . All other bias circuits are in a high impedance state, and only the one active bias circuit establishes a substrate bias V BB at a time. Thus, an advantage of this invention is that power consumption is minimized since only one bias circuit is active at any time and other bias circuits remain inactive. Power consumption by oscillator or pump circuits in the inactive bias circuits is eliminated.
Common bias terminal 19 is also an input of level detector 20 . Level detector 20 detects substrate bias V BB and activates shallow substrate bias signal VBBS when substrate bias V BB is shallow. Shallow substrate bias signal VBBS then activates enable boost signal ENB and disables enable high signal ENH and enable low signal ENL. Active enable boost signal ENB enables boost bias circuit 16 only until a sufficient substrate bias V BB is detected by level detector 20 . Thus, an advantage of this invention is that any mode of operation that causes a shallow substrate bias V BB will activate only boost bias circuit 16 to restore substrate bias V BB .
Referring now to FIG. 2, operational principles of the circuit illustrated by the block diagram of FIG. 1 will be described in detail with reference to a truth table for control circuit 12 . Eight different operating conditions are represented on separate lines 1-8. Only three of them are discussed as examples to describe the table.
As shown in line 1 of the truth table, row logic signal RL 1 _ is active low during an active cycle and burn-in enable signal BINEN and shallow substrate bias signal VBBS are inactive low. Enable high signal ENH is active high and enable boost signal ENB and enable low signal ENL are inactive low. Thus, enable high signal ENH enables only high power bias circuit 14 to generate substrate bias V BB while other bias circuits are disabled.
A shallow substrate bias is only slightly negative (usually less than one volt) with respect to reference supply V SS . Such a condition, as shown in line 2 of the truth table, will activate shallow substrate bias signal VBBS . Row logic signal RL 1 _ is active low and burn-in enable signal BINEN is inactive low. Enable boost signal ENB then becomes active high, and enable high signal ENH and enable low signal ENL are inactive low. Thus, enable boost signal ENB enables only boost bias circuit 16 to generate substrate bias V BB while other bias circuits are disabled.
In standby or precharge mode, as shown in line 3 of the truth table, row logic signal RL 1 _ is inactive high and burn-in enable signal BINEN and shallow substrate bias signal VBBS are inactive low. Enable low signal ENL is active high and enable high signal ENH and enable boost signal ENB are inactive low. Thus, enable low signal ENL will enable only low power bias circuit 18 to generate substrate bias while other bias circuits are disabled. Other control circuit input combinations operate in a similar manner such that only one bias enable signal is active high at any time for each line of the truth table.
Referring now to FIG. 3, there is shown an oscillator 24 which may be included in either of bias circuits 14 , 16 , or 18 . For example, an oscillator 24 for bias circuit 14 has enable terminal 13 connected to one input of NAND gate 30 . The output of NAND gate 30 is connected to a series of inverters to provide an odd number (7) of signal inversions between an input of NAND gate 30 and oscillator output terminal 22 . This odd number of signal inversions provides the unstable condition necessary for oscillation. A high signal level at output terminal 22 is presented to an input of NAND gate 30 through feedback path 44 . After seven gate delays, the signal at output terminal 22 goes low. After another seven gate delays, the signal at output terminal 22 goes high again. The output signal at terminal 22 continues to oscillate in this manner while the signal at enable terminal 13 is high. Capacitors 46 , 48 , 50 , 52 , and 54 are connected in a distributed manner between the inverter chain and reference supply V SS . These capacitors may be connected to the reference supply V SS , as described, or any reference supply, or they may be parasitic elements formed by the next gate input capacitance. Drive strengths of NAND gate 30 and inverters 32 , 34 , 36 , 38 , 40 , and 42 , together with capacitors 46 , 48 , 50 , 52 , and 54 determine the operating frequency of the oscillator 24 .
Referring now to FIG. 4, a pump circuit 58 which may be included in either of bias circuits 14 , 16 , or 18 will be described in detail. For example, a pump circuit 58 for bias circuit 14 has input terminal 22 connected to the oscillator output terminal of FIG. 3 . Except for inverter 60 , the pump circuit comprises two symmetrical half pumps such that one half pump is in a pump cycle while the other half pump is in a precharge cycle. Inverter 60 provides a complementary input to NOR gate 64 . Delay elements 66 and 68 control overlap during signal transitions at terminal 22 . When the signal at input terminal 22 goes from high to low, NOR gate 64 output goes low. The output of inverter 72 turns P-channel precharge transistor 78 off by coupling its gate high through P-channel capacitor 76 . No current is pumped back to common bias terminal 19 through P-channel diode 84 because it is reverse biased. After a short delay established by element 68 , both inputs of NOR gate 62 go low resulting in a high output. This causes the output of inverter 70 to couple the gate of P-channel precharge transistor 80 low through P-channel capacitor 74 , thereby initiating precharge of the gate of P-channel capacitor 76 to reference supply V SS . This transition simultaneously transfers charge from the substrate connected to common bias terminal 19 through P-channel diode 82 to the gate of P-channel capacitor 74 . A subsequent low to high transition of the signal at terminal 22 will repeat this sequence of events with roles of each half of the pump reversed. Thus, the gate of P-channel capacitor 74 will be precharged to reference supply V SS , and more charge is transferred from the substrate connected to common bias terminal 19 through P-channel diode 84 to the gate of P-channel capacitor 76 .
Referring now to FIG. 5, an embodiment of either of bias circuits 14 , 16 , or 18 will be described in detail. Here, the bias circuit comprises the oscillator 24 of FIG. 3 and the pump circuit 58 of FIG. 4 . In this embodiment, for example, oscillator circuit 24 output signal is connected to the input of pump circuit 58 at terminal 22 . Thus, each cycle of the pump circuit 58 of high power bias circuit 14 corresponds to a cycle of oscillator circuit 24 . Parametric values of components of the pump circuit are modified to pump the required quantity of charge corresponding to the frequency of oscillator circuit 24 .
Referring now FIG. 6, another embodiment of either of bias circuits 14 , 16 , or 18 will be described in detail. Here, the bias circuit omits the oscillator 24 of FIG. 3 and includes only the pump circuit 58 of FIG. 4 . In this embodiment, for example, high power bias circuit 14 has pump circuit input terminal 22 connected directly to terminal 13 from control circuit 12 of FIG. 1 . Thus, each cycle of the pump circuit of high power bias circuit 14 corresponds to an active cycle of enable high signal ENH. Parametric values of components of the pump circuit are modified to pump the required quantity of charge corresponding to each active cycle of enable high signal ENH.
Referring now to FIG. 7, an example of level detector 20 will be described in detail. P-channel transistors 86 and 88 form a voltage divider to provide a bias at least one P-channel threshold voltage below positive supply VDD to the gates of P-channel transistors 90 and 96 . P-channel transistors 90 and 96 are on since their sources are connected to positive supply V DD In normal operation, substrate bias V BB is more negative than one P-channel threshold voltage with respect to reference supply V SS . The gate to source voltage of P-channel transistor 94 is about one P-channel threshold voltage, so the source voltage of P-channel transistor 94 is less than reference supply V SS . The gate to source voltage of N-channel transistor 92 is about one N-channel threshold voltage, and the source of N-channel transistor 98 is connected to reference supply V SS . Thus, the gate to source voltage of N-channel transistor 98 is less than an N-channel threshold voltage above reference supply V SS , and it is turned off. P channel transistor 96 is on and keeps the input of inverter 100 high and shallow substrate bias signal VBBS at terminal 9 remains low.
During parallel test mode, multiple arrays may be activated and peak substrate current may exceed the capacity of high power bias circuit 14 . This may cause substrate bias V BB to rise within one P-channel threshold voltage of reference supply V SS . The gate to source voltage of P-channel transistor 94 is about one P-channel threshold voltage, so the source of N-channel transistor 92 is more positive than reference supply V SS . Since the gate to source voltage of N-channel transistor 92 is about one N-channel threshold voltage, the gate to source voltage of N-channel transistor 98 is greater than one N-channel threshold voltage and it is turned on. N-channel transistor 98 overrides P-channel transistor 96 , the input of inverter 100 is pulled low, and shallow substrate bias signal VBBS at terminal 9 goes high. This causes control circuit 12 to activate only enable boost signal ENB. Enable high signal ENH and enable low signal ENL remain low. Enable boost signal ENB enables boost bias circuit 16 , which transfers the additional charge necessary to restores a normal substrate bias V BB .
Although the preferred embodiment of this invention describes the generation of a substrate bias V BB that is negative with respect to reference supply V SS , it should be noted that the benefits of this invention may be achieved for a variety of applications. For example, referring now to FIG. 4, N-channel transistors might be substituted for P-channel transistors 74 , 76 , 80 , 82 , and 84 . Then, if the common terminal of N-channel precharge transistors 78 and 80 were connected to positive supply V DD , this invention could produce a high voltage supply that is positive with respect to positive supply VDD for a capacitive load at common bias terminal 19 . Additionally, the level detector of FIG. 7 could easily be modified to enable a boost bias circuit when the high voltage supply is less than one N-channel threshold voltage above positive supply V DD .
Although the invention has been described in detail with reference to its preferred embodiment, it is to be understood that this description is by way of example only and is not to be construed in a limiting sense. It is to be further understood that numerous changes in the details of the embodiments of the invention will be apparent to persons of ordinary skill in the art having reference to this description. It is contemplated that such changes and additional embodiments are within the spirit and true scope of the invention as claimed below.
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A plurality of substrate bias circuits ( 14, 16, and 18 ) are designed to provide a stable substrate reference potential for a variety of operating modes. Only one of the bias circuits is enabled by a control circuit ( 12 ) at any time for any operational mode. An on-demand boost bias circuit ( 16 ) is enabled whenever a level detector ( 20 ) indicates substrate bias has exceeded a predetermined limit during special operating modes such as burn-in or parallel test.
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BACKGROUND OF THE INVENTION
The present invention relates to a method and a device for forming special color effects induced from an electrical lighting element constituted for example by an incandescent lamp, a fluorescent or luminescent discharge lamp, with or without fluorescent material.
The use of especially fluorescent lamps is well known for lighting purposes, but, when supplied with electrical current, they emit only one color, for example white for a white fluorescent lamp.
SUMMARY OF THE INVENTION
The present invention proposes a method and a device allowing the obtention, in addition to the white color, of additional colors, such as the colors violet, green, yellow or other for a fluorescent lamp of white color supplied with an a.c. current.
For that, the method for forming special color effects from a lighting lamp preferentially a fluorescent lamp and supplied with an a.c. current, is characterized in that it consists in periodically supplying the lamp with the electrical current which is pulsed during an emitting time T1 of the electrical current such that a flashing occurs which is visible to an observer, selected so that the cyclic ratio T1/T, where T is the pulsating period, is comprised between 0 and 1, and whose corresponding frequency 1/T is comprised between 1 and 500 Hz; and moving the lamp in accordance with a relative moving speed V into space such as 0<V≦50 m/s or 0<V≦50 rps.
The device for carrying out the above method according to the invention is characterized in that it comprises a transformer supplying with electrical power the fluorescent lamp, whose electrodes are connected to the secondary winding circuit thereof; a power stage disposed in the primary winding circuit of the transformer; an oscillating circuit connected to the input of the power stage and generating thereto a fixed frequency current for supplying the lamp; a semi-conductor element capable of periodically operating the oscillating circuit during a time T1 and a generator for generating a square-wave signal, connected to the semi-conductor element which is rendered conductive during the time T1 selected so that the cyclic ratio T1/T where T is the period of the square-wave signal, is comprised between 0 and 1, the frequency of the square-wave signal being comprised between 1 and 500 Hz.
According to another feature of the invention, the device further comprises an adjustable oscillator delivering a triangular signal of relatively low frequency for controlling the square-wave signal generator, the frequencies of the triangular and square-wave signals being equal.
According to another feature of the invention, the triangular signal generator comprises a variable resistance for adjusting the cyclic ratio.
BRIEF DESCRIPTION OF THE DRAWINGS
For a full understanding of the invention, reference is made to the following description, taken in connection with the accompanying drawings, in which:
FIG. 1 is a schematic view of a fluorescent lamp supplied from electrical batteries and capable of being manually moved for forming special color effects, and
FIG. 2 shows the electronic circuit for supplying the fluorescent lamp according to the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, reference 1 designates a fluorescent lamp having its supplying electrodes 1a, 1b disposed at the two ends thereof, respectively.
The fluoreccent lamp 1 is a tubular lamp containing as internal gas, either argon with mercury vapour (mercury vapour being capable to be used alone), or neon, and has a deposition or settling of fluorescent powder on its internal surface. This fluorescent powder emits the characteristic color of the fluorescent lamp when the latter is supplied in the normal conditions.
For security purposes, the fluorescent tubular lamp may be housed inside a transparent or diffusing protecting tube 2 and firmly positioned in the latter via blocking annular rings 3.
The tube 2 is closed at one end and open at the other end thereof.
The electrodes 1a and 1b are respectively connected, through conductive wires 4, to the two terminals of the secondary winding of a voltage increasing transformer 5 housed within a portion 6 in the form of a longitudinal handle which is fixed in part in the open end of the protecting tube 2. Preferentially, the handle portion 6 has a circular cross-section.
In the handle portion 6 are also housed the electronic device 7 for powering, through the transformer 5, the fluorescent lamp 1 and supplying batteries 8 connected to the device 7.
The assembly constituted by the protecting tube 2 and the handle portion 6 is thus in the form of an autonomous and portable stick which can be manually moved.
As an example, the external diameter of the fluorescent tubular lamp 1 may be about 16 mm and the internal diameter thereof is about 14 mm, with a distance inter-electrodes 1a and 1b of about 40 cm.
The electronic device for supplying the fluorescent lamp 1 according to the present invention is shown in FIG. 2.
This device comprises the transformer 5 for power supplying the fluorescent lamp 1, whose electrodes 1a and 1b are connected to the terminals of the secondary winding 5a of the transformer. The two terminals of the primary winding 5b of the transformer 5 are connected to a power stage 9 including two transistors TR1 and TR2. Transistor TR1 is of NPN type and has irts base electrode connected to an input resistance R1, its emitter electrode connected to one of the terminals of the primary winding 5b and its collector electrode connected to a base resistance R2 of transistor TR2. The latter, also of NPN type, has its emitter electrode connected to the ground and its connector electrode connected to the other terminal of the primary winding 5b of the transformer 5. The emitter of transistor TR1 is also connected to the positive potential of d.c. supply 8, of +6 V, for example.
An oscillating circuit 10 delivers to the input terminal of resistance R1 of stage 9 a signal of relatively medium or high frequency, according to the type of fluorescent lamps or lighting lamps used in the invention, this signal having for example a frequency of about 10 KHz. This a.c. signal is used for feeding or supplying the fluorescent lamp 1 through the power stage 9 and the transformer 5. The oscillating circuit 10 is constituted by two inverting amplifiers A1 and A2 connected in series, the output of amplifier A2 being connected to the resistance R1, and by two resistances R3, R4 and a capacitor C1 connected in common with one of their terminals, resistances R3 and R4 being respectively connected with their other terminals to the input and output of amplifier A1 while the other terminal of capacitor C1 is connected to the output of amplifier A2. Of course, the output current frequency of circuit 10 may be adjusted by only changing the values of resistances R3, R4 and of capacitor C1. Moreover, the inverting amplifiers A1 and A2 are of the type restituting to the output thereof the input signal which is supplied thereto, while inverting it.
A semi-conductor element, constituted in the present case by a diode D1, has its cathode connected to the input of inverter amplifier A1 while its anode is connected to the output of a generator circuit 11 which generates a square-wave signal. This generator comprises a resistance R5 and a capacitor C2 connected in series, with the capacitor C2 connected to the input of a voltage inverter amplifier A3 connected in series with another inverter amplifier A4, whose output is connected to the anode of diode D1. A voltage divider circuit formed with resistances R6, R7 and adjustable resistance RV1 connected in series, is connected between the ground and the +6 V potential. The slide contact of adjustable resistance RV1 is connected through a resistance R8 to the input of inverter amplifier A3. Generator 11 generates a square-wave signal, whose frequency 1/T is equal to the frequency of the signal from oscillating circuit 12 connected to resistance R5, and whose cyclic ratio T1/T where T1 is a time during which the square-wave signal is high and T is adjustable in accordance with the variable resistance RV1. For example, this cyclic ratio may vary from about 10 to about 90%.
The oscillating circuit 12 delivers to the input of generator circuit 11 a triangular signal of adjustable frequency, and preferentially a relatively low frequency comprised between about 1 to about 500 Hz. The adjustable oscillator 12 comprises two inverter amplifiers A5 and A6 connected in series, the output of amplifier A6 being connected to input terminal of resistance R5 of circuit 11 through a capacitor C3. A variable resistance RV2 is connected between input terminal of amplifier A6 and terminal common to capacitor C3 and resistance R5. To this common terminal is also connected a resistance R9, whose other terminal is connected to the input of amplifier A5.
It is to be noted that inverter amplifiers A1-A6 are in a same integrated circuit, which is for example the 4049 circuit of TEXAS INSTRUMENTS.
The operation of the supplying device of the fluorescent lamp according to the present invention results in part from the above description and will be described more in detail herebelow.
The adjustable oscillator 12 delivers to generator circuit 11 the triangular signal of relatively low frequency, which is adjusted with variable resistance RV2, which generator circuit generates a square-wave signal of a frequency (or period T) identical to that of the triangular signal and of a cyclic ratio T1/T defined by resistance RV1. During the time T1 where the square-wave signal is high, diode D1 is rendered conductive for allowing the oscillator 10 to generate a signal of relatively medium or high frequency to the input of power stage 9. This power stage 9 thus gives to the transformer 5 the necessary power for the starting of the fluorescent lamp which is then supplied with a.c. current.
Thus, during time T1 where diode D1 is rendered conductive, the fluorescent lamp 1 is supplied with a a.c. current of relatively medium or high frequency, and then, when diode D1 is non-conductive during time T2 where the square-wave signal from circuit 11 is low (T2=T-T1), oscillator 10 is then blocked and fluorescent lamp 1 is not supplied during time T2, this process being periodically repeated at period T. In other words, there is a strong lighting of fluorescent lamp 1 during emitting time T1 of a.c. current defined by its true intensity I1 and no lighting of this lamp during emitting time T2 of the a.c. current defined by its true intensity I2, with 0≦I2<I1 such that a flashing occurs which is visible to an observer.
By selecting a cyclic ratio T1/T above to or equal to 0.05 but lower than 0.9, with a frequency 1/T of the square-wave signal above or equal to 10 Hz but below or equal to 50 Hz, and by manually moving the stick assembly of FIG. 1 in accordance with the moving or displacing speed below or equal to 5 m/s or by manually turning the stick assembly into space to a rotative speed below or equal to 10 rps, a color effect is produced from fluorescent lamp 1, in addition to its own color, the colors being visually observed by an observer distant from the person handling the stick.
As an example, very distinct visual color effects are produced with a white fluorescent lamp containing neon for a vaue of T1/T=0.2 and a frequency value 1/T=20 Hz.
Moreover, the possible smaller width, corresponding to the direction of the displacement of the lamp, of the lighting portion seen by the observer is, the most spectacular is the color effect. Thus, if the fluorescent lamp 1 is manually moved as explained hereabove, this width will correspond to the external diameter thereof. If the tubular lamp has a diffusing protecting screen, the width will be that of the screen. In practice, a width below 40 mm is recommended, a width of about 15 mm is good while a width of 10 mm is excellent.
According to the invention, instead of manually moving or displacing the fluorescent lamp 1 as precedingly described, the latter may be fixed to a rotating plate or sheel, whose rotating speed is fixed or variable, the observer distant from the rotating plate then observing the same spectacular effect of colors observed in the case of the use of the stick assembly of FIG. 1. This effect is produced for a cyclic ratio T1/T such as 0<T1<1 for a frequency 1/T such as 0<1/T<500 Hz, with a rotation speed such as 0<V≦50 rps. These same values may be used in the case where the fluorescent lamp 1, instead of being rotated with a rotating plate, would be moved with an appropriate mechanical device along a path, rectilinear or not, at a speed V such as 0<V≦50 m/s.
The best results have been observed, in the case of a rotating plate or of the mechanical device displacing or moving along a rectilinear or not rectilinear path the fluorescent lamp, for the following values:
0.2≦T<100 Hz
0.01≦T1/T≦0.99
and 0<V≦50 m/s
or 0<V≦50 rps.
The invention has been described hereabove as only applied to the supply of a fluorescent lamp but it is obvious that identical results may be provided with other lighting lamps such as for example incandescent lamps having nevertheless a fluorescent material.
Moreover, the values precedingly indicated correspond to a spectacular effect from a supply with a d.c. voltage of 6 volts, but it is obvious that this voltage may vary while using the same electronic components of the device shown in FIG. 2. For example, a voltage of 12 volts will increase these effects (a stronger lighting, an increase of the tubular lamp length, etc. . . . ). Moreover, the device according to the present invention may also be supplied from d.c. current from the conventional network current instead of using the batteries 8 rendering the stick assembly portable. It is also possible to provide the protecting screen, protecting the fluorescent lamp, which is transparent or semi-transparent, colored or not.
On the other hand, the mechanical device capable of moving the fluorescent lamp along a path may be an oscillating type device.
In the case of a fluorescent lamp or luminescent lamp containing only a gas or a mixture of different gases, the presence of one or several fluorescent materials or settling form supplementary color effects due to the retentivity difference of the different materials during time.
As explained hereabove, the fluorescent lamp 1 moves with respect to an observer but it is obvious that the same color effect may be observed or seen in the case where the observer moves with respect to the fluorescent lamp or when there is an object which moves between the observer and the fluorescent lamp.
It is further to be noted that the characteristics in frequency and intensity of the a.c. current for supplying the fluorescent lamp are such that the latter does not need its conventional starting system for lighting it under the action of the emitted electrical current during time T1.
As way of example, the different components of the electronic circuit of FIG. 2 may have the following values: RV1 4700 ohms, RV2 470,000 ohms, R1 3300 ohms, R2 33 ohms, R3 1,000,000 ohms, R4 22,000 ohms, R5 560,000 ohms, R6 1800 ohms, R7 3300 ohms, R8 220,000 ohms, R9 1,000,000 ohms, C1 200 micro-farads, C2 1 micro-farad and C3 1 micro-farad. TR1 is BC 328 and TR2 is TIP 31A,D1 1N40148. A1-A4 are 4049 MOS. The characteristics of transformer 5 are such that its primary circuit has 35 windings for a wire diameter of 30/100 mm and its secondary circuit has 650 windings for a wire diameter of 10/100 mm, thus a voltage increase ratio of 18.5.
The device according to the invention is particularly intended for forming special color effects for theater carnivals, fun fairs, majorette sticks, systems of roads sign, electric signs, automotive equipments, luminous truncheon or others.
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The present invention relates to a method and a device for forming special color effects wth at least an electrical lamp which is supplied with a pulsed current and moved by a relative movement into space. The device supplies the electrical lamp with an electrical current which is pulsed during a time T1 in accordance with a pulsating period T, the cyclic ratio T1/T varying between 0 and 1 and the frequency 1/T varying from 1 to 500 Hz.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a method for the targeted initiation of a regeneration of a particle filter in an exhaust-gas duct of an internal combustion engine which has a catalytic converter downstream of the particle filter in the flow direction of the exhaust gas, the regeneration of the particle filter taking place by means of an oxidative burn-off of the particles during the regeneration phase.
[0002] The invention also relates to a device for carrying out the method according to the invention.
[0003] To reduce the particle emissions of diesel engines, and in the future also increasingly of spark-ignition engines (EU6 limit values from 2014), particle filters are used in the exhaust-gas duct of the internal combustion engines. The exhaust gas is conducted through the particle filters, which separates the solid particles contained in the exhaust gas and retains said solid particles in a filter substrate. As a result of the mass of soot accumulated in the filter substrate, the particle filter becomes blocked over time, which manifests itself in an increase in the exhaust-gas counterpressure with an adverse effect on engine power and fuel consumption. For this reason, the accumulated mass of soot must be discharged from time to time. Said filter regeneration takes place during separate regeneration phases by means of an oxidative burn-off of the particles, which takes place independently as an exothermic reaction if an exhaust-gas temperature of at least 580° C. and an adequately high oxygen concentration in the exhaust gas are present. The course of the regeneration can be controlled by means of the composition of the exhaust gas and the exhaust-gas temperature.
[0004] The exhaust-gas treatment of internal combustion engines requires further components aside from the particle filter. For example, in the case of spark-ignition engines operated on a homogeneous concept, the pollutants hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NO x ) are converted by means of a three-way catalytic converter. In the case of lean-burn concepts, a storage catalytic converter for nitrogen oxides is usually connected downstream. The lowest possible discharge of pollutants is achieved by means of lambda regulation, wherein the fuel/air mixture supplied to the internal combustion engine is regulated on the basis of the oxygen concentration in the exhaust gas. The oxygen fraction present in the exhaust gas is described by a lambda value which has a value of 1 for stoichiometric combustion, a value of >1 for an excess of oxygen and a value of <1 for a lack of oxygen. The lambda value is measured by means of corresponding lambda probes arranged in the exhaust-gas duct.
[0005] The regeneration of the particle filter takes place generally when a limit value for an exhaust-gas counterpressure is exceeded, as already described above. This may be detected by means of a suitable model and adapted by means of a differential pressure measurement. Here, the soot oxidation and therefore the regeneration of the filter are influenced significantly by the exhaust-gas temperature and the residual oxygen content. Since there must be an excess of oxygen in the exhaust gas for the burn-off of the particles, it is not possible in said phase for the mixture composition of the internal combustion engine to be freely selected according to the demands of the driving mode. It is therefore desirable to determine an end of the regeneration in order to be able to switch to normal driving operation.
[0006] An as yet unpublished patent application from the applicant with the official application number DE 10 2009 028237.8 discloses a method for the monitoring and regulation of the regeneration of a particle filter in an exhaust-gas duct of an internal combustion engine, wherein the regeneration of the particle filter takes place by means of an oxidative burn-off of the particles during a regeneration phase. Here, it is provided that, during the regeneration phase of the particle filter, the internal combustion engine is operated at a lean operating point at least temporarily during lean-burn operating phases or during a mixture oscillation, and that the regeneration of the particle filter is monitored by means of the time profile of a second signal of a second lambda probe arranged downstream of the particle filter, or the time profile of a second characteristic variable derived therefrom, in comparison with the time profile of a first signal of a first lambda probe arranged upstream of the particle filter in the exhaust-gas direction, or the time profile of a first characteristic variable derived therefrom, during the lean-burn operating phases or during the mixture oscillation. It is disadvantageous here that the regeneration takes place within a lean-burn phase, in which other harmful exhaust-gas constituents cannot be optimally removed.
[0007] Since it is also not possible to ensure that the engine is regularly in an operating state in which the regeneration of the particle filter can take place independently, facilities for a forced initiation of the regeneration must be provided.
SUMMARY OF THE INVENTION
[0008] It is therefore an object of the invention to provide a method for the forced initiation of the regeneration, which method permits reliable regulation and monitoring of the regeneration of the particle filter.
[0009] It is also an object of the invention to provide a corresponding device for carrying out the method.
[0010] The object of the invention relating to the method is achieved in that, when the internal combustion engine is in the warm operating state but the temperature is still insufficient for a regeneration of the particle filter, measures are temporarily taken to increase the exhaust-gas temperature upstream of and/or in the particle filter.
[0011] The object relating to the device is achieved in that the device has a control unit by means of which the initiation, control and monitoring of the regeneration of the particle filter are carried out and by means of which signals of a first lambda probe arranged upstream of the particle filter in the exhaust-gas direction, signals of a second lambda probe arranged downstream of the particle filter and/or downstream of the catalytic converter in the exhaust-gas direction and/or signals of at least one temperature sensor can be evaluated, wherein by means of a program routine implemented in the control unit, measures can be carried out for a limited time to targetedly increase the temperature upstream of and/or in the particle filter.
[0012] In the regeneration of a particle filter, use is made of the fact that, when the exhaust-gas temperature lies in a range which permits a regeneration, the regeneration takes place automatically while maintaining the conversion of the other pollutant components, since the untreated exhaust gas still has a certain residual oxygen fraction (0.5 to 0.7%). Furthermore, under suitable conditions, a regeneration may also take place by means of the so-called heterogeneous water-gas equilibrium reaction (C+H 2 O CO+H 2 ). Here, use is made of the fact that, when there is a lack of oxygen, the reaction kinetics for the regeneration of the particle filter changes. Here, no additional oxygen is required in the exhaust gas. Water is always present in the exhaust gas from the reaction. Said reaction however takes place only at relatively high temperatures, that is to say >800° C. The requirement for a regeneration of the particle filter may be detected from a suitable model or by means of a corresponding sensor arrangement, for example differential pressure measurement, wherein for the initiation of the regeneration, firstly the further ambient conditions, such as for example the exhaust-gas temperature and the present operating mode, are checked.
[0013] With the method and the device, a regeneration of the particle filter may also be initiated within operating states of the internal combustion engine in which the ambient conditions for the regeneration are not optimal. This is the case for example if the internal combustion engine is operated for a very long time in part-load operation or at low loads, such as is often the case for example in city traffic. Furthermore, adequate conversion of all harmful exhaust-gas components must be ensured even during said phase, which can likewise be achieved by means of the method.
[0014] One option for this is a targeted reduction in efficiency with the aim of increasing the exhaust-gas temperature. For this purpose, strategies may be used which conventionally serve for heating up a catalytic converter when the engine is still cold. Therefore, in one preferred method variant, it is provided that, for the targeted initiation of the regeneration of the particle filter, the ignition angle is shifted in the direction of a late ignition time, and therefore the exothermic reaction is displaced increasingly into the exhaust stroke, which leads to an increase in the exhaust-gas temperature, as a result of which the regeneration of the particle filter can, as described above, take place independently.
[0015] To compensate the reduction in efficiency and the associated torque loss, it may be provided here that, during the shift of the ignition angle, a throttling action of the internal combustion engine is reduced. Since regulation is also carried out to a stoichiometric air ratio, this strategy engine is exhaust-gas-neutral, that is to say an adequate conversion of all harmful exhaust-gas components can be ensured. On account of the reduction in efficiency, however, a certain increase in fuel consumption must be accepted in this regeneration phase.
[0016] Aside from the late adjustment itself, in another method variant, the so-called homogeneous-split (HSP) operating mode may be used in addition to the late adjustment of the ignition angle. Said operating mode is used for example to bring the catalytic converter up to operating temperature as quickly as possible after the start phase, that is to say when the engine is still cold. Here, a second injection, which has a stabilizing effect, in the compression stroke is utilized to subject the ignition to an extreme delay, such that a large proportion of the combustion energy can be utilized to increase the exhaust-gas enthalpy, which, in the application of the method according to the invention, heats the particle filter in a very short time (within a few seconds) to the operating temperature required for regeneration. High ignition reliability can be attained by means of said second injection or if appropriate by means of further injections. Furthermore, as a result of the placement of the rich mixture in the vicinity of the spark plug, increased burn-through stability can be obtained.
[0017] A further option for actively initiating the regeneration is to increase the exothermic reaction in a three-way catalytic converter. It is provided here that, from a lambda regulating mode around a lambda value of 1, regulation to a lambda value of >1 (lean-burn operation) is carried out for a limited time and an oxygen accumulator of the catalytic converter is thereby filled, and subsequently, after the filling of the oxygen accumulator, a lambda value of <1 is set by pilot control, as a result of which the oxygen accumulator in the catalytic converter is emptied. Said process, which is highly exothermic overall, causes the exhaust system to be heated up, and on account of the overall lambda value of 1, is approximately neutral with regard to the conventional exhaust-gas components.
[0018] Said change in the lambda regulating mode, which has hitherto been known for heating up the catalytic converter or for the desulfurization of a NO x accumulator catalytic converter, can be used to particularly great effect if the particle filter is designed as a combined particle filter/catalytic converter and has a catalytic coating. Here, particularly effective heating of the particle filter can be obtained by means of said measure.
[0019] The regeneration must be monitored for all active measures. It is therefore provided that the temperature in the particle filter is used as a regulating variable for the initiation of the regeneration and for the monitoring of the regeneration, wherein said temperature is determined directly by means of at least one temperature sensor arranged in or on the particle filter or being derived from signals of lambda probes which are arranged in the exhaust duct upstream and/or downstream of the particle filter and which serve for lambda regulation or being determined on a modeled basis from an exhaust-gas temperature model. The intensity and the duration of the heating-up process can thereby be influenced in a targeted manner.
[0020] One device variant therefore provides that an exhaust-gas temperature model is implemented within the control unit and the regulating variable for the regeneration of the particle filter is a temperature of the particle filter derived from said exhaust-gas temperature model. Continuous monitoring can thereby be ensured.
[0021] A preferred use of the method as described above in terms of its variants is the implementation for the regeneration of a close-coupled particle filter in the exhaust-gas duct of an internal combustion engine which is designed as a spark-ignition engine and which has intake pipe injection or direct injection. It is advantageous here that existing lambda probes or existing sensor concepts may be utilized, because lambda probes for lambda regulation are already provided in the exhaust-gas duct of spark-ignition engines, such that the signals thereof may be jointly used for the initiation, control and regulation of the regeneration of the particle filter, as a result of which the method can be implemented particularly cost-effectively in future spark-ignition engines with particle filters.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be explained in more detail below on the basis of an exemplary embodiment illustrated in the figures, in which:
[0023] FIG. 1 shows an internal combustion engine having a particle filter arranged in the exhaust-gas duct thereof and having a downstream pre-catalytic converter and a main catalytic converter or an LNT/SCR catalytic converter, and
[0024] FIG. 2 shows the internal combustion engine with a combined particle filter/catalytic converter and a downstream main catalytic converter or an LNT/SCR catalytic converter.
DETAILED DESCRIPTION
[0025] FIG. 1 shows an internal combustion engine 10 having an air supply 11 and having a particle filter 15 arranged in an exhaust-gas duct 12 and having a downstream pre-catalytic converter 17 and also a main catalytic converter 18 which may be designed as a three-way catalytic converter. The exhaust gas of the internal combustion engine 10 which is purified in the particle filter 15 and the catalytic converters 17 , 18 is discharged via an exhaust gas outlet 20 . The lambda value of the exhaust gas in the exhaust-gas duct 12 directly downstream of the internal combustion engine 10 is determined by means of a first lambda probe 13 . In said region, the temperature of the exhaust gas is additionally determined by means of a temperature sensor 14 . Particles are accumulated in the particle filter 15 during the operation of the internal combustion engine 10 . This increases the exhaust-gas counterpressure. The particle filter 15 must therefore be burned off, and thus regenerated, when required. A regeneration can take place only when the exhaust-gas temperature lies above approximately 580° C.; this can be detected by means of the temperature sensor 14 . Furthermore, an adequate amount of oxygen for a combustion must be present. This can be detected by means of the first lambda probe 13 . A second lambda probe 16 is arranged in the exhaust-gas duct 12 downstream of the particle filter 15 and the downstream pre-catalytic converter 17 . For post-cat lambda regulation, said second lambda probe may also be arranged downstream of the main catalytic converter 18 .
[0026] From the difference between the output signals of the first lambda probe 13 and of the second lambda probe 16 , it is possible to determine the extent to which the burn-off of particles in the particle filter 15 consumes oxygen. If no difference can be detected between the signals, the burn-off has ended. The signals of the first lambda probe 13 and of the second lambda probe 16 and also the output signal of the temperature sensor 14 are supplied to a control unit 21 .
[0027] A program sequence for comparing the signals and for initiating, controlling and monitoring the regeneration is implemented in the control unit 21 . It is provided here that the signals of the first lambda probe 13 , the signals of the second lambda probe 16 and/or signals of the temperature sensor 14 can be evaluated as significant regulating variables, wherein by means of the program routine implemented in the control unit 21 , measures can be carried out for a limited time to targetedly increase the temperature upstream of and/or in the particle filter 15 . In a further exemplary embodiment, an exhaust-gas temperature model is implemented within the control unit 21 . A temperature of the particle filter 15 modeled using said exhaust-gas temperature model is provided as a regulating variable for the regeneration of the particle filter 15 . Here, the control unit 21 may be integrated in the engine controller of the internal combustion engines 10 , in which the lambda regulation is conventionally implemented.
[0028] Said basic design is shown for an operating variant in which regulation is carried out to a lambda value of 1. For a lean-burn operating mode with a lambda value λ>1, it is alternatively possible for an LNT/SCR catalytic converter 19 to be provided instead of the main catalytic converter 18 . Here, LNT stands for “Lean NO x Trap” and refers to a catalytic converter whose surface is impregnated with barium salts and platinum and other noble metals and which can therefore adsorb nitrogen oxides from the engine exhaust gas. SCR stands for “Selective Catalytic Reduction” and refers to a selective catalytic reduction of nitrogen oxides in exhaust gases. The chemical reaction in the SCR catalytic converter is selective, that is to say the nitrogen oxides are preferably reduced, while undesired secondary reactions (such as for example the oxidation of sulfur dioxide to form sulfur trioxide) are substantially suppressed. Said nitrogen oxides, typically NO and NO 2 , can be stored on the catalytic converter surface. If such a catalytic converter is periodically exposed to a rich fuel/air mixture, said nitrogen oxides can be converted into nitrogen, carbon dioxide and water.
[0029] FIG. 2 schematically shows the arrangement from FIG. 1 in a modified arrangement. Here, in contrast to FIG. 1 , the particle filter 15 and the pre-catalytic converter 17 are combined to form a combined particle filter/catalytic converter, the particle filter having a catalytic coating. Here, too, a main catalytic converter 18 is provided for an operating variant in which regulation is carried out to a lambda value of 1. For a lean-burn operating mode with a lambda value λ>1, it is alternatively possible for an LNT/SCR catalytic converter 19 to be provided instead of the main catalytic converter 18 , as shown in FIG. 1 .
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A method for the targeted initiation of a regeneration of a particle filter in an exhaust-gas duct of an internal combustion engine which has a catalytic converter downstream of the particle filter in the flow direction of the exhaust gas, the regeneration of the particle filter taking place by means of an oxidative burn-off of the particles during the regeneration phase.
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BACKGROUND OF THE INVENTION
There are various ways of measuring static unbalance of a rotary member, such as a grinding wheel, motor vehicle wheel and the like. One form of such a procedure, as disclosed in DE 29 45 819 A1 and Hofmann News 8 (05.85 D) and 11 (10.88) involves determining the axial moment of inertia of the rotary member when mounted pivotably in a horizontal position, that is to say with the axis of rotation of the rotary member extending vertically. In that procedure, in dependence on a deviation of the rotary member from its initial horizontal position, a return force effective to return the rotary member to its horizontal position is produced in a regulating circuit as a control parameter, and the value of the static unbalance from which the rotary member suffers is formed from the measured return force. To perform that procedure, the rotary member to be measured is placed with its axis of rotation vertical, on a horizontal balancing tray member or plate which is mounted in such a way as to be pivotable, preferably by means of a gimbal or Cardan-type mounting arrangement. If the rotary member suffers from an unbalance, that means that the center of gravity of the rotary member is shifted and a moment corresponding to the static unbalance from which the rotary member is suffering is operative about the pivot mounting axis of the balancing tray member or plate. If the balancing tray member or plate is subjected, at a constant spacing from the pivot mounting axis thereof, to a force which causes the balancing tray member or plate to return to its horizontal position, the force applied, being proportional to the static unbalance, makes it possible to determine the unbalance of the rotary member.
In an apparatus for carrying out that procedure, the deviation of the balancing tray member or plate is detected by suitable means and, in dependence on the deflection signal, an electronic measuring and regulating system produces an electrical current and supplies it to a return or restoring means which includes an electromagnet unit and which is operable to return the weighing tray member or plate into its horizontal position. The current forming the control parameter for the regulating circuit is proportional to the force applied by the return or restoring means and is thus also proportional to the static unbalance of the rotary member to be tested.
The above-outlined operating procedure and the apparatus for carrying out same enjoy the advantage that the fact of using the described compensation principle means that there is no residual deflection of the balancing tray member or plate, and thus the unbalance measurement result is not falsified in that way. When measuring rotary members which are of different weights however it is not possible to adhere to a specific cycle time for carrying out the unbalance measuring operation as the regulator involves constant regulating parameters and depending on optimum adjustment of the regulator, positioning of the balancing tray member or plate in its horizontal position, when dealing with different types of rotary member which involve different weights, requires different positioning times. Hitherto, optimum adjustment of the system has been effected in relation to a low rotary member weight in order to avoid the generation of high control parameter signals which could result in the regulating circuit suffering from instabilities. When measuring types of rotary member which are of relatively high weight however, it has to be accepted in that situation that the time for the balancing tray member or plate to return to its horizontal position and thus the cycle time involved in carrying out the rotary member unbalance measuring procedure is increased.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method of measuring static unbalance of a rotary member, which affords reliable results with an optimum regulating action, while nonetheless involving short operating cycle times.
Another object of the present invention is to provide a rotary member static unbalance measuring method which is more rationally applicable to a wide range of rotary member weights.
Still another object of the present invention is to provide a rotary member static unbalance measuring method which is simple to operate while nonetheless affording a substantial level of accuracy.
A further object of the present invention is to provide an apparatus for measuring static unbalance of a rotary member, which is of a simple design configuration and which also gives reliable and stable results.
Still a further object of the invention is to provide a rotary member static unbalance measuring apparatus which is quick and easy to operate.
In accordance with the present invention, in a first aspect, these and other objects are attained by a method of measuring static unbalance of a rotary member, by determining the axial moment of inertia of the rotary member which is mounted pivotably in a horizontal position. In dependence on a deviation of the rotary member from its horizontal position, under the effect of an unbalance thereof, a return force for returning the rotary member to its initial horizontal position is produced as a control parameter in a regulating circuit. The value of the static unbalance of the rotary member is formed from the measured return force, and regulation of the return force is further effected in dependence on the weight of the rotary member being measured.
In accordance with the invention, in a second aspect, the foregoing and other objects are achieved by means of an apparatus for measuring static unbalance of a rotary member comprising a balancing tray member or plate for carrying the rotary member to be measured, the balancing tray member being mounted pivotally and being disposed in a horizontal position in a rest condition of the apparatus. A measurement value pick-up or detector means is operable to produce a deviation or deflection signal when the balancing tray member departs from its horizontal position, the deviation signal being passed to a regulating means which receives the deviation signal as a regulating parameter. A return means is connected to the regulating means and receives a control parameter signal therefrom, to control return of the balancing tray member to its horizontal position. A measuring means is operable to determine the control parameter signal which is thus proportional to the static unbalance. The apparatus further includes means for setting the regulating parameters of the regulating means in dependence on the weight of the rotary member being measured.
The teaching of the present invention thus provides for optimization of the regulating parameters or regulating coefficients which, in the case of a PID-regulator are the proportional coefficient, the integrating coefficient and the differentiating coefficient, over the entire range of weights of rotary members to be measured. In that way, for each type of member or for each weight of member involved, in a static unbalance measuring operation, it is possible to provide for the shortest possible cycle time in particular in regard to positioning of the balancing tray member in a horizontal position. The procedure and apparatus according to the invention preferably use a digital PID-regulator. There are various possible ways of ascertaining the PID-regulator parameters before or during the regulating and measuring procedure, for example it is possible to set the regulating parameters or factors in the manner disclosed in `Grundkurs der Regelungstechnik` [`Basic Course in Regulating Procedures`] by Dr L Merz and Dr H Jaschek, 8th edition, pages 186 to 191, in particular by reference to the characteristics and behaviour of the regulating circuit at the stability limit. Generally the rotary members to be measured which may be for example grinding wheels, motor vehicle wheels and the like, are subdivided into given types or categories of rotary member. Certain specific rotary member data, inter alia a specific weight, are allocated to the individual types or categories of rotary members. The specific rotary member weight relating to each given type is taken into consideration in accordance with the principles of the invention to provide for optimum setting of the regulating parameters or coefficients of the regulator such as the PID-regulator. If the rotary member weight is not known, it will be appreciated that it can be ascertained by balancing before carrying out the operating procedure of the invention.
Further objects, features and advantages of the invention will be apparent from the following description of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a diagrammatic view of an embodiment of a rotary member static unbalance measuring apparatus according to the invention, and
FIG. 2 shows a graph illustrating a regulating procedure for a type of rotary member to be measured.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring firstly to FIG. 1, shown therein is a measuring apparatus for measuring the static unbalance of a rotary member, comprising a balancing tray member or plate 1 which in a rest condition of the apparatus is disposed in at least substantially horizontal position and which is mounted pivotably about an axis as indicated at 2. Preferably, the apparatus involves a Cardan-type or gimbal mounting assembly for the balancing tray member 1, for use with two axes which are displaced through 90° relative to each other, for example using the configuration disclosed in DE-29 45 819 A1 which is hereby incorporated by reference.
Reference numeral 3 in FIG. 1 denotes a rotary member to be measured, which is arranged on the balancing tray member 1 in such a way that the axis of rotation about which the rotary member 3 rotates in normal operation thereof is disposed vertically and thus perpendicularly to the upward surface of the at least substantially horizontally disposed balancing tray member 1.
Reference numeral 4 identifies a measurement value pick-up means or detector for detecting a deviation X of the balancing tray member 1 from its rest position, that deflection corresponding to an angle φ of pivotal movement of the balancing tray member 1 about its mounting axis 2. Instead of a measurement value pick-up device 4, it is also possible to provide two measurement value pick-up devices which are preferably in the form of distance-measuring detectors, as illustrated for example in Hofman News 11.
An output signal is delivered by way of an analog-digital converter 8 from the measurement value pick-up device 4. A reference value is held in a storage device or memory 11 and specifies a predetermined deflection x (amplitude). The difference of the output signal and of the reference signal is passed as a deviation parameter to a digital PID-regulator 6. The PID-regulator 6 forms a control parameter signal which is passed by way of a digital-analog converter 9 to a power portion 12. In dependence on the control parameter signal generated by the digital PID-regulator 6, the portion 12 produces a drive current which is passed to a restoring or return device 7. The device 7 includes an electromagnet unit which is thus fed with the drive power from the power portion 12. The electromagnet unit applies to the balancing tray member 1 a return or restoring force for returning the balancing tray member 1 to its horizontal position, after it has been deflected therefrom under the effect of an unbalance of the rotary member 3 carried thereon. The restoring force is thus proportional to the static unbalance of the rotary member 3 which caused the balancing tray member 1 to be pivoted about its axis 2 from its original horizontal position, by the deflection distance indicated by X and the angle φ.
The drive current supplied by the power portion 12 to the return device 7 is proportional to the force to be applied by the return device 7. Therefore, for determining the static unbalance of the rotary member 3, it is possible to measure that current as is known for example from the construction disclosed in DE-29 45 819 A1. By virtue of the fact that the drive current is proportional to the control parameter signal in digital form as applied to the digital-analog converter 9, or the control parameter in analog form outputted by the converter 9 to the power portion 12, the static unbalance of the rotary member 3 may also be directly specified by a display of the suitably scaled control parameter signal at a display device 5 which may be of an analog or digital nature, depending on the circuitry involved. When using the analog form, the display device 5 is preferably connected between the digital-analog converter 9 and the power portion 12, as illustrated in the FIG. 1 circuit. When using a digital set-up however, the display device 5 is then preferably connected between the regulator 6 and the digital-analog converter 9.
The arrangement according to the invention also involves a read only memory 10 which is suitably connected to the digital regulator 6. The memory 10, in relation to different types of rotors 1 . . . n, stores the respective optimum regulating parameters (proportional coefficient P, integrating coefficient I and differentiating coefficient D) in dependence on the different weights of the respective types of members 1-n. In that connection each of the regulating parameters is set, in a weight-related manner, to an optimum value which is in accordance with the following relationship: ##EQU1## in which RP identifies the optimum regulating parameter, RPmax identifies a regulating parameter which is the optimum one for a maximum rotary member weight, Gmax identifies a maximum rotary member weight, Gr identifies the weight of a rotary member to be measured, and m identifies the quotient from the difference between maximum and minimum rotary member weight (Gmax-Gmin) and the difference from the two optimum regulating parameters (RPmax-RPmin) for the maximum and minimum rotary member weights, that is to say: ##EQU2##
Each of the three regulating parameters is calculated in a weight-dependent manner for each type of rotary member 1-n, in accordance with the two relationships set forth above, and stored in the memory 10 at appropriate locations associated with the respective types of rotary members.
In performing an unbalance measuring operation, the operator of the apparatus illustrated is then only required to introduce the appropriate type of rotary member or weight of rotary member, into an input device 13 which is suitably connected to the memory 10, and the corresponding regulating parameters are then available for the regulating procedure and the measuring operation, at the PID-regulator 6.
Another possible procedure for weight-dependent optimization of the individual regulating parameters in relation to the various types of rotary member 1-n may be as set out below, involving effecting adjustment in respect of the type of rotary member in a measuring operation in which the weight of the rotary member to be measured is approximately ascertained.
Referring therefore now to FIG. 2, using fixedly defined regulating parameters, the balance tray member indicated at 1 in FIG. 1 is firstly positioned in a horizontal position, which constitues the rest condition of the apparatus, without a loading applied thereto by a rotary member thereon, within the period of time indicated at to in FIG. 2. That phase is indicated by the solid line in FIG. 2. The regulating deviation is then as indicated at OV in FIG. 2. Then, to produce a jump in the reference value involved, the reference value indicated at 11 in FIG. 1 is caused to jump, and the period of time tmin which is then required for the balancing tray member 1 to assume 50% of its new reference position which corresponds for example to a jump in the reference value 11 as indicated at 1V in FIG. 2, is measured. The same procedure is effected with maximum loading on the balancing tray member 1 with a rotary member 3 involving maximum rotary member weight. The dashed line in FIG. 2 shows the regulating procedure involved in that situation. The measured time tmax is necessary in order for the balance tray member 1 when loaded with the maximum rotary member weight to assume 50% of the freshly set reference value. The time measurement operation may also be effected relative to another percentage of the fresh reference position, for example at 70% thereof.
FIG. 2 also shows the regulating procedure, indicated in dash-dotted line, for a type of rotary member to be measured. In that situation, when using the reference value voltage jump, the time required for the balancing tray member 1 to assume 50% of the new reference position thereof is indicated at tr in FIG. 2.
Optimization of the respective regulating parameters RP in dependence on the different weights of the types of rotary member 1-n is effected in accordance with the following relationships: ##EQU3##
In the foregoing relationship, tr represents the time required in relation to the respective rotary member to be measured, for that rotary member to be moved into 50% of the reference position set by the jump in control parameter, in accordance with the procedure described above with reference to FIG. 2. In that connection, it is preferable for the slope in respect of the straight-line equation m to be stored beforehand in a suitable memory so that, after the measuring operation has been carried out, for the purposes of ascertaining the time tr, the above-indicated value m is immediately available for determining the optimum regulating parameters.
The optimum regulating parameters (P-, I- and D-components) which are determined in that way in respect of the respective types of rotary members are stored in the memory 10 shown in FIG. 1, and called up in dependence on the type of rotary member to be measured, for input into the PID-regulator 6. As FIG. 1 shows, the regulator 6, the memory 11 for the reference value, the memory 10 and the input device 13 may be combined together to form a digital portion or unit as indicated at 14.
For types of rotary members which are not included in the memory 10, it is also possible, prior to carrying out the rotary member unbalance measuring operation, to determine the time tr required for the rotary member to be measured, and for the regulating parameters RP to be calculated in accordance with the foregoing relationships (3) and (4) in a suitable calculating device or computer (not shown), the regulating parameters then being introduced into the regulator 6 in order for the unbalance measuring procedure to be effected.
Input of the fresh reference position may be effected for example by supplying a suitable digital value to the digital-analog converter 9. The power portion 12 will then supply a suitable current which is passed to the return means 7 which then moves the balancing tray member 1 from the horizontal starting position into the new reference position.
It will be appreicated that the above-described procedures and apparatus have been set forth solely by way of example and illustration of the principles of the present invention and that various modifications and alterations may be made therein without thereby departing from the spirit and scope of the invention.
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In a method and apparatus for measuring static unbalance of a rotary member, involving determining the axial moment of inertia of the rotary member which is mounted pivotably in a horizontal position in a balancing system, about an axis of the balancing system, a deviation of the rotary member from its horizontal position is detected and a return force for returning the rotary member to the horizontal position is produced in response to a control parameter from a regulating circuit in dependence on the detected deviation, with regulation of the return force also being effected in dependence on the weight of the rotary member. The value of the static unbalance of the rotary member is formed from the measured return force.
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FIELD OF THE INVENTION
This invention relates to double door installations for residential use between the interior of the house and a terrace or patio.
BACKGROUND OF THE INVENTION
As pointed out in my U.S. Pat. No. 4,052,819, it is common in double door installations where one of the doors is normally inactive to use a T-shaped astragal mounted on the vertical edge of the inactive door, in such manner that one side of the head of the T overlaps and seals the outside front edge of the inactive door, and the other side of the head portion of the T extends into the swinging path of the active door so as to act as a stop and weather seal when the active door is closed. The invention of my prior patent was directed to providing a double door astragal assembly of that type which could be adjusted into sealing engagement with the front surfaces of both doors independently and irrespective of misalignment of the doors.
It is also conventional--particularly in commercial installations involving relatively heavy double doors--to provide an astragal which is mounted in the top and bottom of the door frame independently of the doors, and which will therefore stand alone in the doorway when both doors are opened. If the installation is one wherein the entire doorway may be needed on some occasions, for passage therethrough of something too wide for a single doorway, provision has been conventionally made for temporarily removing the astragal, by the release of bolts, screws or similar semi-permanent mounting means.
SUMMARY OF THE INVENTION
The present invention has as its primary objective the provision of a double door installation particularly adapted for residential use which will offer the following advantages:
1. The installation includes an astragal which is separate from both doors and has its own mounting in the head jamb and sill.
2. Each door latches to the astragal independently of the other door and can be opened independently of the other door.
3. Either door can be the primary access door, as determined at the time of installation.
4. The primary access door is provided with a dead bolt lock which extends through the astragal into the other door for increased security.
5. The less active door can be directly locked to the astragal without affecting locking and unlocking of the primary access door.
6. Whenever it is desired to use the full width of the doorway, the astragal can be removed as quickly and easily as the primary access door can be opened, leaving the other door equally freely openable.
7. The installation may be provided with a screen door which is slidably mounted to cover either door opening, and which will seal against the frame and the astragal in either of its limit positions.
Other objects and advantages, and the means by which the invention accomplishes them, are pointed out hereinafter in connection with the Description of the Preferred Embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a double door installation in accordance with the invention with both doors closed;
FIG. 2 is a similar view showing one door open;
FIG. 3 is a similar view showing both doors open and the astragal removed;
FIG. 4 is a somewhat diagrammatic fragmentary perspective view illustrating the connection between the bottom end of the astragal and the sill;
FIG. 5 is a view similar to FIG. 4 showing the releasable connection between the top end of the astragal and the head jamb;
FIG. 6 is a view similar to FIG. 4 illustrating the lock portion of the astragal;
FIG. 7 is an enlarged fragmentary section on the line 7--7 in FIG. 2;
FIG. 8 is an enlarged fragmentary section on the line 8--8 in FIG. 1 showing the dead bolt mechanism for locking both doors together and to the astragal.
FIG. 9 is a fragmentary perspective view, partly in phantom, further illustrating the dead bolt locking mechanism; and
FIG. 10 is a fragmentary view in horizontal section illustrating the provision of the invention for sealing a sliding screen door to the jambs and the astragal.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the installation illustrated in FIGS. 1-3, doors 20 and 22 and astragal 25 are mounted in a conventional door frame comprising a head jamb 30, side or hinge jambs 31 and 32 and a sill assembly 33, which together define the rectangular opening in which the doors are mounted by the usual hinged connections to the two side jambs. The left-hand door 20 is shown as the primary access door, as indicated by the handle 35 thereon which operates the dead bolt latch as described hereinafter. In addition, each door is provided with an operating handle 36 for a conventional latch mechanism which enables it to be opened independently of the other door when neither door is locked to the astragal.
FIG. 2 illustrates that when only the primary access door 20 is open, the astragal 25 remains in place, and the other door 22 is latched, and may also be locked, thereto. Both doors can be opened without removing the astragal, as indicated by phantom lines in FIG. 3, but it is a feature of the invention that the astragal is quickly and easily removable to leave the entire doorway open, as also illustrated in FIG. 3.
Referring now to FIGS. 4-7, the astragal 25 has a generally T-shaped configuration in horizontal section with the stem 40 of the T being proportioned to fill the space between the two doors 20-22 in their closed positions. The head of the T is normally on the outer side of the doorway and provides arms 41-42 which define stops establishing the closed positions of the two doors which open inwardly of the doorway. The slots 43 receive and hold the barbed mounting portions of magnetic or compression weather strip 44, and the portion 45 of the astragal is a plastic thermal break connection between the metal head and stem portions of the T.
The mounting for the astragal 25 in the door frame includes a sill anchor 50 which is fixed on the sill 33 and is provided with a vertical projection 51 that fits in complementary relation within the hollow lower end of the stem portion 40 of the astragal. At its upper end, the astragal is releasably secured to the head jamb 30 by a latch assembly indicated generally at 55 and an anchor 56 of generally inverted cup shape which is set in a complementary recess in the head jamb 30 and functions as a keeper for the flush bolt 60, which is mounted for vertical sliding movement in the hollow upper end of the astragal stem portion 40.
As shown in FIG. 5, the flush bolt 60 is biased upwardly--so that its upper end normally projects above the top of the astragal--by a compression spring 61 received in a slot 62 in the body of the flush bolt 60 and supported at its lower end by a binding post 63 which extends across the astragal stem 40 and is received in a groove 64 at the bottom of the slot 62 to establish the upper limit position of flush bolt 60. A slot 65 in each side of the astragal stem 40 provides access to a handle portion 66 of the flush bolt so that it can be pulled down against the spring 61 to retract it from within the anchor 56 when the astragal is to be removed from the door frame.
In an alternative construction at the lower end of the astragal 25, it may be provided with a second flush bolt assembly mating with a second anchor 56 set in the sill 33. In this case the flush bolt need not be slidable in the astragal but may be fixed thereto with its operative end projecting beyond the astragal for insertion in its complementary anchor in the sill.
Strike plates 70 of opposite hand are mounted on the opposed sides of the astragal stem portion 40 and include the usual keeper openings 72 which are aligned with similar openings 73 in the sides of the astragal portion 40 for receiving the latch members 75 operated by the handles 36 on the two doors. Both strike plates 70 are also provided with keeper openings 77 for the dead bolt 80, which in the illustrated embodiment is carried by the left-hand door 20. As shown in FIG. 7, the proportions of the parts should be such that if the dead bolt assembly is of a conventional type providing one inch of throw for the dead bolt 80, then in its locking position, the dead bolt will extend completely through the holes 81 in the astragal which are aligned with the strike plate openings 77, and also through the strike plate 82 in the edge of door 22, so that both doors will be locked together and to the astragal.
With the construction as described thus far, release of the dead bolt will allow each of the two doors to be opened independently of the other, by operation of their latch handles 36. Accordingly, provision is made by the invention for independently locking the less active door 22 to the astragal--by means which cannot be released except by removal of the astragal assembly from the door frame, as now described.
Referring to FIGS. 7 and 8, before the strike plate 82 is mounted on the edge of the less active door 22, a bore 83 is drilled in the door which is of sufficient diameter and depth, e.g. 1 inch by 11/2 inches, to receive a U-shaped member 85 of resilient metal strap material which serves both as a dead bolt for door 22 and a keeper for the dead bolt 80 carried by door 20. This member 85 has outwardly turned flanges 86 on its ends, and in its normal, unstressed condition, its two outer ends will be spaced further apart than the width of the keeper openings 81 in the astragal.
The member 85 is mounted in position when the door 22 is closed, by pressing its two ends together sufficiently to insert it completely through the opening 77 on the strike plate 70 for door 20 until it snaps in place with its shoulders 86 inside the astragal portion 40. This installation is completed by inserting a filler block 88 of wood or other suitable material and of solid U-shape into the interior of the member 85 inside the bore 83.
The length of the block 88 is such that when it is fully inserted inside the member 85, there will be adequate room in the outer end of the bore 82 to receive the dead bolt 80, and the member 85 will therefore serve as a keeper for the dead bolt. However, the width and thickness of block 88 are such that when the dead bolt is released in order to open door 20, the member 85 will continue to act as a dead bolt connection between door 22 and the astragal, with the block 88 preventing the member 85 from being compressed sufficiently to withdraw its shoulder portions 86 from inside the astragal, even if an attempt is made to pull door 22 open.
Accordingly, once the member 85 and block 88 are in place, the door 22 can be opened only by first removing the astragal assembly, following release of the flush bolt 60 from its anchor 56, since as the astragal is then removed sidewise it will withdraw members 85 and 88 from bore 82. The locked condition of door 22 can be readily reestablished by repeating the installation of members 85 and 88.
As previously noted, either of the two doors 20 and 22 can be established as the primary access door, and this does not have to be determined until after the doors have been installed. Selection must then be made of the appropriate latch assembly in accordance with whether the left or right-hand door will carry the dead bolt mechanism. Thereafter, the less active door will simply remain closed, and cannot be opened without first removing the astragal assembly as described. However, the provision of the simple latch assembly 55 at the head of the astragal makes its removal no more difficult or time consuming than opening of the door itself. Also, if it is desired to use both doors alternatively, the member 85 can be set aside, and each door can then be opened or latched by its own bundle 36 and latch 75.
It is conventional in double door installations of the illustrated type to provide a screen door which is mounted for sliding movement in the frame 30-33 between limit positions at each end of the frame. The invention promotes such installation and use of a screen door, and also insures that it is in properly sealed relation with the astragal and one of the side jambs 31-32 in each of its limit positions.
Referring to FIG. 10, the screen door 99 has its top and bottom mounted for sliding movement in conventional tracks (not shown) in the head jamb 30 and sill 33. A flashing strip 100 is mounted in each side edge of the screen door 99, by means such as the telescoping snap connection 101, with the flashing strip extending inwardly of the door opening.
As shown in FIG. 10, when the screen door 99 is in its limit position at the left-hand side of the frame and covering the opening for the left-hand door 20, one flashing strip 100 will seal against the jamb 31, while at the same time, the flashing strip 100 on its other side will seal against the arm portion 41 of the astragal. Similarly at its other limit position, the flashing strips 100 will seal against the jamb 32 and the arm portion 42 of the astragal. It will therefore now be seen that if desired for ventilation purposes, the keeper assembly 85-88 can be removed to permit door 22 to be opened, and to remain open, with the screen door 99 aligned with its opening, while the door 20 continues to be used as the primary access door without the necessity of opening and closing the screen door.
While the product and method herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise product and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.
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A double door installation includes an astragal which is removably mounted in the head jamb and sill portions of the door frame independently of the doors, but the combination includes a locking mechanism in one door which incorporates a bolt arranged to project through the astragal into the other door to effect firm locking of both doors to each other and to the astragal.
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BACKGROUND TO THE INVENTION
1. The Field of the Invention
The present invention relates to systems for rotating discs in disc data stores. In particular it relates to such systems employing brushless D.C. motors where it is desired to brake the rotation of the disc or discs.
2. The Prior Art
It is well known to provide an electric motor to rotate one or more discs in a disc data store. The one or more discs have informational data recorded thereon in a plurality of concentric data storage tracks. The tracks are accessed for the recording or recovery of data by the positioning at selectable radii on the disc of a data recording or recovering transducer to interact with selected tracks. The disc or discs is or are generally magnetic in which case the transducer is a magnetic read/write head.
An important class of disc drives involves the use of a magnetic head which flies a few microinches over a thin magnetic film on a rapidly rotating disc supported by a thin layer of air pulled round by the disc in proximity to its surface. Whereas in the past it was the practice to withdraw the head from the surface of the disc before allowing the disc to cease rotating, with the advent of low cost rotary actuators for positioning the head over the disc for use in dust-free enclosures it has become difficult to do so and in the popular Winchester technology the head is actually moved to a parking track where it is allowed to land on the disc when the disc is stopped.
When landing a head on the disc there is always a risk of damaging the disc surface thereby throwing up debris to catch beneath the head and cause data errors on some other track or indeed to adhere to the head and adversly affect its flying characteristics. Debris can also induce wear on other tracks. The risk of damaging the landing zone is minimized if the rotation of the disc is rapidly braked thereby minimizing the time and distance of abrasive contact between head and landing track after the disc speed has dropped far enough to allow the head to cease flying.
It is well known to employ an electric induction motor to rotate the disc. The induction motor tends to be very large for the particular job in order to provide sufficient starting torque and is not very efficient during running thereby causing the generation of unwanted heat requiring to be dissipated. The induction motor provides little motor braking when power is removed and in order to brake the disc in reasonable time it is necessary to provide a separately operable brake. The brake is required to be very large and is therefor undesirable.
As an improvement over the induction motor, it is also known to provide a D.C. commutator motor for rotating the disc. The commutator motors tend to be smaller and more efficient for the same service. When it is desired to stop the disc a large amount of motor braking is available capable of bringing down the speed of the disc to a low enough level in an acceptably short time for a small mechanical brake to bring the disc to a complete halt. Commutator motors however suffer from commutator arcing which induces noise voltages into the data channel of a disc drive so causing data errors and which can contravene R.F.I. standards.
It has therefore become the practise to employ brushless D.C. motors for rotating the disc wherein hall effect switches take the place of the commutator to switch power via power transistors and the like to the windings. The control of brushless D.C. Motors is relatively complicated. The necessity for disc braking imposes a yet further burden.
SUMMARY OF THE INVENTION
It is therefore desirable to provide a simple and automatic method for braking a disc in a disc drive rotated by a brushless D.C. motor.
According to a first aspect, the present invention consists in a disc drive comprising a brushless D.C. motor for rotating the disc and a switch circuit operable to short out the windings of said brushless motor to provide motor braking for the disc.
According to another aspect, the present invention consists in a disc drive according to the first aspect comprising a solenoid operated brake operable to apply mechanical braking to said disc whenever the current in said solenoid falls below a predetermined limit, said solenoid receiving the current to said windings during the operation of said motor and said switch circuit supplying the short circuit current from said windings to said solenoid when it is desired to brake said disc, said solenoid thereby allowing the application of said brake whenever the rotational speed of said motor falls below a predetermined limit.
According to yet another aspect the present invention consists in a disc drive according to the above aspect wherein said solenoid is employable during the operation of said motor as a choke common to all of said windings for the smoothing of current flow therein.
According to yet another aspect the present invention consists in a disc drive according to any features of the above aspects taken singly or in combination.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
In a preferred embodiment a brushless motor rotates a shaft which is coupled to rotate a disc. A brake shoe preferably is operable to bear upon the shaft to brake the disc. The shoe is preferably at the distal end of a solenoid arm. The solenoid arm is preferably spring loaded to push the brake shoe against the shaft. A solenoid preferably pulls the solenoid arm away from the shaft thereby disengaging the shoe therefrom. The solenoid arm is preferably spring loaded such that the shoe engages the shaft if the current in the solenoid falls below a predetermined limit. A motor drive circuit preferably provides electrical current for driving the windings of the motor and for the solenoid.
The motor preferably comprises a plurality of windings. The drive circuit preferably comprises a corresponding plurality of selectably operable transistor switches for supplying current to the windings in response to a corresponding plurality of externally received winding energization commands. There are preferably three windings. One end of each winding is preferably coupled to the collector of its individual transistor switch. The other end of each winding is preferably connected to a common point. The common point is preferably connected to a first end of the winding of the solenoid. The second end of the winding of the solenoid is preferably connected via a first ganged switch to a power supply rail. Each collector of each transistor switch is preferably coupled via a diode to a common energy absorbing circuit coupled intermediately between the diodes and the common point between the second end of the winding of the solenoid and the first ganged switch. A second ganged switch is preferably connected across said energy absorbing circuit. The energy absorbing circuit preferably comprises a resistor. The energy absorbing circuit also preferably comprises a capacitor. The energy absorbing circuit is preferably operable to receive recoil energy from the windings when the current in each one thereof is cut off by its associated transistor switch.
The first and second ganged switches are preferably ganged together such that the first switch is open when the other is closed and vice versa.
During the operation of the motor the current in the windings preferably flows through the solenoid, the first switch being open and the second closed, so maintaining the brake shoe clear of the shaft by maintaining the current in the solenoid above the predetermined level, allowing the inductance of the solenoid to smooth the current through the windings, and permitting the energy absorbing circuit to absorb the energy transients from the windings.
The braking of the motor is preferably initiated by the operation of the ganged switches such that the first ganged switch is opened, thereby disconnecting the supply rail and the second ganged switch is closed, thereby shorting out the energy absorbing circuit and allowing the back emf of the windings to drive short circuit current through the diodes and through the winding of the solenoid to provide motor braking, the solenoid releasing the solenoid arm when the current in its winding falls below the predetermined level indicatively of the rotation of the motor having fallen below a predetermined speed and the released solenoid arm applying the brake shoe to the shaft to bring the motor to a complete halt from the predetermined speed.
The invention is further explained, by way of an example, by the following description taken in conjunction with the appended drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the mechanical arrangement of the elements of the preferred embodiment of the invention.
FIG. 2 shows a schematic diagram of the electrical arrangement of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows the mechanical arrangement of the preferred embodiment.
A brushless D.C. Motor 10 provides motive torque to a shaft 12. The shaft 12 is coaxially coupled to a disc 14 which is thereby caused to rotate about its axis 16 as indicated by the arrow 18.
A brake shoe 20, conformal to the surface of the circular shaft 12, is disposed in adjacense thereto on the distal end of a solenoid arm 22. The solenoid arm 22 is spring loaded to push the shoe 20 against the shaft 12. The solenoid arm 22 is subject to the pull of a solenoid 24 whenever a current flows in its coil. Whenever the current in the solenoid 24 exceeds predetermined limit the solenoid pull overcomes the spring loading and pulls the arm 22 away from the shaft 12 to disengage the brake shoe 20 from the surface thereof.
A motor drive circuit 26 provides power for the windings of the motor 10 via a motor coupling 28 and current for the solenoid 24 via a solenoid coupling 30.
It is to be appreciated that whereas only one disc is shown, it can be representative of any number of discs on a common axis. It is further to be appreciated that the motor 10 can drive the disc 14 other than through a shaft 12, as an example, being a pancake motor directly driving a disc 14. The brake shoe and shaft 20, 12 combination can be replaced by any mechanically actuatable device capable of stopping the disc 14.
FIG. 2 shows a schematic diagram of the motor drive circuit 26 coupled to the solenoid 24 and to the motor 10.
A first transistor switch 32 is operable in response to a signal on a first input line 34 to allow the flow of current in a first winding 36 of the motor 10, a first end of which is coupled to its collector and a second end of which is connected to a common point 37. A second transistor switch 38 is operable in response to a signal on a second input line 40 to allow the flow of current in a second winding 42 of the motor 10, a first end of which is connected to the collector of the second transistor switch 38 and the second end of which is connected to the common point 37. A third transistor switch 44 is operable in response to a signal on a third input line 46 to allow the flow of current in a third winding 48 of the motor 10, a first end of which is connected to the collector of the third transistor switch 44 and the other end of which is connected to the common point 37.
The common point 37 is connected to a first end of the winding 50 of the solenoid 24. The other end of the winding 50 of the solenoid 24 is connected to a supply point 51. The supply point 51 is connectable to a positive supply rail V+ via a first ganged switch 52.
A first diode 54 is coupled intermediately between the collector of the first transistor switch 32 and a diode star point 55 such that the first diode 54 conducts when the voltage on the collector of the first transistor switch 32 is more positive than the voltage on the star point 55. The star point 55 is connected via a resistor 56 in parallel with a capacitor 58 to the supply point 51. A second diode 60 is connected between the collector of the second transistor switch 38 and the star point 55 to conduct when the collector of the second transistor switch 38 is more positive. A third diode 62 is connected between the collector of the third transistor switch 44 and the star point 55 to conduct when the collector of the third transistor switch 44 is more positive. A second ganged switch 64 is operable to connect the star point 55 directly to the supply point 51.
The first and second ganged switches 52, 64 are collectively operable such that in a first state the first switch 52 is closed and the second switch 64 is open allowing power to be delivered from the rail V+ via the winding 50 of the solenoid 24 to the windings 36, 42, 48 of the motor 10 and providing the parallel combination of the resistor 56 and the capacitor 58 between the star point 55 and the supply point 51, and in a second state the first switch 52 is open removing all motive power from the motor 10 and the second switch 64 is closed connecting the star point 55 directly to the supply point 51.
During operation of the motor 10 the ganged switches 52, 64 are placed in the first state. The windings 36, 42, 48 of the motor 10 are energized in turn in response to signals on the input lines 34, 40, 46. The exact manner of the provision of the external stimulation does not constitute part of the present invention. It may be provided in response to the outputs of hall effect sensors commanding commutation of the current in the windings 36, 42, 48. Alternatively, the stimulation can come from a fixed frequency source or a variable frequency source stimulating each winding in turn to operate the motor 10 in a synchronous manner. It will be appreciated that the motor can be of any kind wherein there are provided a plurality of separate windings operable when shorted out to provide motor braking. While only three phases are shown for the motor 10, it will be appreciated that by obvious modifications to the embodiment any number of phases can be accommodated.
During operation of the motor 10 the current to the windings 36, 42, 48 flows through the coil 50 of the solenoid 24, exceeding the minimum holding value and thereby preventing the brake shoe 20 from engaging the shaft 12. As the current in the windings 36, 42 48 is switched off, the energy transient resultant therefrom is coupled by the appropriate diode 54, 60, 62 respectively to be dissipated in the parallel combination of the resistor 56, and the capacitor 58. It is to be appreciated that the parallel combination of the resistor and the capcitor 56, 58 is representative of any suitable energy absorbing device and can include thermistors, voltage dependent resistors and the like.
When it is desired to brake the motor 10 the ganged switches 52, 64 are placed in the second state. The first switch 52, now open, cuts off all power from the rail so that all drive to the motor 10 stops regardlessly of what the signals on the input lines 34, 40, 46 may be doing. The star point 55 is connected directly to the supply point 51. As the motor 10 coasts without power the windings 36, 42, 48 each generate their own back emf by dynamo effect which is coupled via the diodes 54, 60, 62 to maintain a current in the loop comprising the windings 36, 42, 48, the diodes 54, 60, 62, the star point 55 shorted by the second switch 64 to the supply point 51 and the winding 50 of the solenoid. The maintained current flows in the same direction as the original drive currents and provides motor braking to reduce the speed of the disc 14. The magnitude of the maintained current is a function of the residual speed of the disc 14. As the motor braking brings the speed of the disc 14 below a predetermined speed, the current in the coil 50 of the solenoid 24 falls below the predetermined holding value and the solenoid releases the solenoid arm 22 whose spring loading pushes the brake shoe 20 against the shaft 12 to brake the residual rotation of the disc to a halt.
The ganged switches 52, 64 may be variously implemented. They can be contacts on a common relay in which case those skilled in the art will be aware of different ways of energizing the relay to monitor power supplies, to respond to a master on/off switch for the disc drive and the like. Equally the switches 52, 64 can be additional contacts on the on/off master switch for the disc drive. Those skilled in the art will be aware that the first switch 52 can be opened before the second switch 64 is closed, and that as a consequence the operation of the second switch 64 can be made dependent upon the operation of the first switch in a master-slave fashion.
Those skilled in the art will be aware of many other uses for the invention as described outwith the rotation of discs in disc data stores.
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A system for rotating a data storage disc in a disc drive and for rapidly bringing the disc to a halt comprises a brushless motor fed with direct current in its windings by a motor drive circuit which current is also fed to a solenoid to hold a spring loaded solenoid arm from pressing a brake against a shaft to brake the disc, the motor control circuit using the current caused by back emf in the windings of the motor to provide motor braking while passing the current through the solenoid which applies the brake when the motor speed falls below a predetermined limit, the solenoid also being employed as a current smoothing choke.
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RELATED APPLICATION DATA
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/298,843, filed Jun. 15, 2001, which is incorporated by reference as if included herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to a device for at least partially stabilizing vortex or other unstable flow in a flow channel, and in particular to a substantially radial, vaneless diffuser defined by an annular slot in the sidewalls of the flow channel.
BACKGROUND OF THE INVENTION
[0003] The use of a diffuser to reduce the velocity and increase the static pressure of a fluid passing through a system is well known. As a fluid flow enters a diffuser, kinetic energy in the fluid is converted to a static pressure rise due to conservation of angular momentum when swirl is present and conservation of linear momentum. Diffusers are often used in combination with a bladed impeller or combined inducer/impeller within a particular system.
[0004] Bladed impellers or combined inducer/impellers are the key component of centrifugal, mixed flow, and axial pumps, compressors, blowers, and fans to move various fluids (i.e., air, water, vapor, or combination thereof) through a system. Depending on the condition of the fluid flow as it approaches the inlet to the equipment, the design of bladed impellers or combined inducer/impellers may be critical to control instability in the fluid flow and prevent instability in the equipment overall and to control other fluid problems such as non-collateral boundary layers. Examples of instabilities in fluid flow include vortices (in any type of fluid) often created from the impeller/inducer design itself, cavitating flow in liquids caused by vortices in the fluid, or a combination thereof, and boundary layer flows which are not collateral with the main flow direction.
[0005] In the case of conventional pumps, bladed impellers or combined inducer/impellers are typically used to deal with very low inlet pressure conditions. As the fluid passes through the bladed section, it experiences a rise in pressure. In the case of a cavitating liquid/vapor flow, the increase in pressure may cause the vapor bubbles in the flow to collapse and/or condense thereby causing the fluid to transfer from a vapor phase back to a liquid phase. For certain applications, this is extremely critical. Turbopumps, aircraft fuel pumps, and many industrial pumps are concerned with very low inlet pressure conditions.
[0006] An unfortunate aspect of inducer performance is that the cavitating flow cannot be completely prevented under various operating conditions. Performance remains constant down to a very low inlet pressure, but with sufficient reduction in the inlet pressure a complete breakdown in head results. This typically occurs when cavitated (two-phase) flow, originating principally from a part-span or tip vortex, substantially fills the impeller passages. These instabilities result from the development of cavitating flow in the inducer. If this developing flow is unable to maintain a consistent, uniform, and steady flow pattern within the inducer, oscillations result. These oscillations can be serious, leading to auto-oscillation where a dynamic instability exists in the impeller and begins to propagate instabilities into the entire pumping network and possibly into downstream elements. As a result, a diffuser may be used in the inducer region to help remove a portion of either the cavitating flow or the vortices that can lead to cavitating flow in the fluid.
[0007] In addition to applying a diffuser to the field of pumps, the same application can be made for centrifugal, mixed flow, and axial compressors, blowers, and fans. The fundamental difference is that the cavitation that was suppressed or removed in the case of the pumps does not apply at all in the case of compressors, fans, and blowers which handle various gases. Cavitation only occurs in liquids. Nonetheless, it is possible to set up a leading edge vortex and other forms of inlet instability, which accompanies appropriate shaping of a vane leading edge. Such a vortex or other unstable zone may contain substantial energy that can negatively impact the operation of the respective equipment if not controlled.
[0008] As mentioned above, the use of a diffuser to reduce the velocity and increase the static pressure of a fluid passing through a system is well known when dealing with common inlet flows, but has not been previously used to swallow a tip vortex. Prior patented devices utilize various means in an attempt to address the problems related to inlet cavitation and the development of other flow instabilities within the inlet region. Allowing the flow to be pulled off through a cover slot or set of holes has been achieved in early patented work by Chapman and others (See Model 250-C301C28B Compressor Development by Dennis C. Chapman, General Motors Corporation). Allowing flow to be pulled off and then reentered upstream has also been accomplished through earlier patents by Jackson (U.S. Pat. No. 3,504,986, issued on Apr. 7, 1970), Cooper (U.S. Pat. No. 4,375,937, issued on Mar. 8, 1983), Meng (U.S. Pat. No. 4,708,584, issued on Nov. 24, 1987), and Edwards (U.S. Pat. No. 2,832,292, issued on Apr. 29, 1958).
[0009] Prior attempts at designing an effective diffuser for dealing with highly compromised flows such as a tip vortex have failed for various reasons. Previous diffuser designs are often focused on re-circulating flow rather than effectively diffusing flow. For example, flow is often bled off and routed through a tortuous flow path that dissipates the energy contained in the flow. By dissipating the energy in the fluid flow, the pressure contained in the fluid is reduced thereby reducing the effectiveness of any diffusing device present. In addition, diffusers of prior inventions often include vanes. Vaned diffusers have been known to cause additional instability in the flow field by causing distortion. In addition, vanes increase the difficulty of fabrication and installation of a diffuser. Still other diffuser designs fail to consider the particular characteristics of the flow field. For example, the length of other diffuser slots is often too short to cause enough static pressure to collapse and/or condense the vapor bubbles within a particular cavitating flow.
SUMMARY OF THE INVENTION
[0010] The present invention is a device for at least partially stabilizing an unstable fluid flow within a flow channel by capturing at least a portion of the unstable fluid within a vaneless diffuser. An additional aspect of the invention includes maintaining and harnessing a substantial portion of the energy contained in the fluid as it flows through the diffuser in order to take additional advantage of the fluid. An example of additional advantage includes discharging the diffuser effluent into the flow channel to help reduce instability in the flow channel. An additional aspect of the present invention is a diffuser design that is directly related to the particular fluid flow characteristics in which it will operate.
[0011] In one embodiment of the present invention, a device for at least partially stabilizing an unstable fluid flow within a flow channel includes an inducer or impeller residing at least partially within the flow channel, the inducer or impeller having rotatable blades for drawing flow into, or being driven by the flow in, the flow channel, the inducer or impeller rotatable about an axis, the flow channel defined by interior sidewalls of a housing, the housing at least partially surrounded by an inlet plenum, and the housing including an exit. The device also includes at least one diffuser slot having an inlet and an exit, the inlet in fluid communication with the flow channel, the diffuser slot(s) being substantially radial with respect to the axis. The device also includes at least one passage in fluid communication with the exit of the diffuser slot(s). The passage(s) may be in fluid communication with the inlet plenum, the housing exit exit, an area downstream of the housing exit, the flow channel, or a combination thereof. Finally, the diffuser slot(s) of the device generally have a radius ratio greater than or equal to 1.03 and are free of vanes.
[0012] In another embodiment of the present invention, a device includes multiple diffuser slots located along the flow channel. The flow is bled off of the flow channel at various points into the multiple diffuser slots. The flow in the slots is then treated similarly to that in the embodiment described above. It is contemplated within the present invention that any combination of diffuser slots may be utilized depending on the application.
[0013] In still another embodiment of the present invention, a device includes at least one diffuser slot located on either side of the housing exit vane and housing exit. Vortex or unstable flow is captured within the diffuser slot(s) and either discharged to the inlet plenum, back into the housing exit vane, or downstream of the housing exit.
[0014] In yet another embodiment of the present invention, any one of the devices having a diffuser slot as described above also includes a particle capture slot and particle trap. The particle capture slot is in fluid communication with the diffuser slot to capture any particles contained in the fluid as the fluid passes radially through the diffuser slot. The particles flow from the particle capture slot into a particle trap where they are contained.
[0015] Other features, utilities and advantages of various embodiments of the invention will be apparent from the following more particular description of embodiments of the invention as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For the purpose of illustrating the invention, the drawings show a form of the invention that is presently preferred. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:
[0017] [0017]FIG. 1 is a side section view of one embodiment of the present invention;
[0018] [0018]FIG. 2 is a side section view of another embodiment of the present invention;
[0019] [0019]FIGS. 3 a - 3 d are side section views of various embodiments of the present invention; and
[0020] [0020]FIG. 4 is a side section view of yet another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention is directed to a device including a vaneless diffuser for reducing the velocity and increasing the static pressure of a fluid flowing through a system and for generally increasing the overall flow stability of a system. An example of the disclosed invention is depicted schematically in FIGS. 1 - 4 , although it should be understood that the present invention is not limited to this (or any other) particular embodiment, but rather is intended to cover all devices that fairly fall within the broad scope of the appended claims.
[0022] The device of the present invention includes a vaneless diffuser for reducing the velocity and increasing the static pressure of a fluid flowing through a system. The vaneless diffuser of the present invention can be retrofitted to many open or closed impeller inducer pump configurations (i.e., with or without a shroud) or other equipment including bladed inducers or impellers (e.g., air-handling equipment). A substantially radial slot diffuser is placed around the inducer at a suitable position along the internal flow channel of the pump housing and provides an alternate path for the cavitated flow resulting from an unstable part-span (also called tip) vortex, which causes the instability of the impeller flow path. The inlet to the diffuser slot forms a substantially contiguous ring around the inducer and is followed by a channel of substantially radial design that provides a diffuser for the part-span vortex which naturally migrates radially away from the inducer axis due to its angular momentum. The substantially radial slot has a length that is selected to provide effective diffusion and to appropriately raise the static pressure.
[0023] In the case of a cavitating flow, which is trapped at the core of the vortex, the rise in static pressure causes the cavitating flow to be substantially collapsed and/or condensed from vapor back to liquid phase. Sufficient pressure recovery is achieved in the diffuser slot to return the fully condensed flow back into the inlet flow path via re-entry slots/holes and/or to the inlet plenum or downstream via return slots/holes. In the case of an unstable air flow, the diffuser slot helps to stabilize the flow by drawing at least a portion of the vortex or other unstable flow away from the inlet area thereby improving the upstream flow channel conditions.
[0024] In FIG. 1, diffuser 100 of the present invention generally includes an inlet 102 , a diffuser slot 104 , and one or more passages (passages include one or more re-entry slots 108 and/or one or more return slots 110 ). Inlet 102 is formed in the internal sidewalls 112 of a housing 113 and leads into diffuser slot 104 . Diffuser slot 104 is typically vaneless and substantially radial with respect to a centerline axis 107 of a flow channel 103 and generally forms an annular ring that encircles flow channel 103 . Diffuser slot 104 leads to at least one re-entry slot 108 and/or at least one return slot 110 which are also formed in sidewalls 112 of housing 113 . Note that the term “channel” as contained herein may mean any conduit for fluid flow and includes any cross-sectional shape. In addition, the term “housing” generally refers to the body of any type of equipment that may contain a fluid channel. Finally, the term “fluid” may refer to any gas including air, liquid, vapor, or any combination thereof.
[0025] While diffuser slot 104 in particular preferably extends substantially radially relative to axis 107 of flow channel 103 , the present invention encompasses divergence of up to about 65 degrees from a perfectly radial relationship with axis 107 . Thus, the term “substantially radial” encompasses such divergence from a perfectly radial relationship. The degree of divergence from a perfectly radial relationship that is encompassed by the present invention is influenced, as those skilled in the art will appreciate, by factors such as orientation of slot inlet flow velocity vector and diffuser/plenum space constraints.
[0026] The edges 116 of inlet 102 to diffuser slot 104 are typically rounded to facilitate flow into the slot. However, inlets 102 having squared edges are also contemplated in the present invention. The walls 105 that define diffuser slot 104 are typically parallel as in FIG. 1. However, in other embodiments it is conceivable that the walls defining a diffuser slot may not be parallel (e.g., may include one or more pinch points along the slot).
[0027] Diffuser 100 of the present invention and more specifically the centerline of inlet 102 and diffuser slot 104 are located in flow channel 103 along housing sidewall 112 in relation to a leading edge 120 of an inducer blade 122 joined with an impeller 124 . The one or more re-entry slots 108 typically form a pathway from diffuser slot 104 to an area of flow channel 103 immediately upstream of an inducer region 126 (i.e., the region formed by leading edge 120 of inducer blade 122 and a hub 128 of impeller 124 ).
[0028] Typically, any rotating, swirling, vortex, cavitating, or other unstable flow conditions are found adjacent leading edge 120 of inducer 122 within inducer region 126 . Consequently, re-injection of diffused flow from re-entry slot 108 in the region of flow channel 103 immediately upstream of inducer region 126 will help reduce the amount of rotation in the area of re-injection thereby reducing upstream flow corruption from the unstable flow within inducer region 126 .
[0029] The one or more return slots 110 typically form a pathway that leads from diffuser slot 104 to an area within an inlet plenum 130 outside of flow channel 103 and/or a pathway that leads from diffuser slot 104 to an exit 134 of flow channel 103 or to an area downstream of exit 134 . Inlet plenum 130 is generally the area surrounding flow channel 103 and housing 113 from which fluid flow is drawn.
[0030] As illustrated in FIG. 1, diffuser slot 104 typically has a rectangular cross-section. In addition, one or more re-entry slots 108 and one or more return slots 110 also have substantially rectangular cross-sections. Although the term “slot” generally refers to a narrow passage, in embodiments of the present invention it is conceivable that the term slots may include passages with varying dimensions depending on the specific application. Accordingly, as used herein, the term “slot” may refer to passages of any size or cross-section.
[0031] As one skilled in the art will recognize, the specific dimensions and location of diffuser 100 of the present invention are selected based on the characteristics of the flow and the vortex within the flow (often influenced by inducer design) and the specific requirements for the diffuser (e.g., controlling or stabilizing unstable flow, and/or extending the cavitation performance of the pump, etc.). Other variables that impact the specific dimensions of diffuser 100 include the dimensions of flow channel 103 , impeller 124 , and inducer 122 as well as the flow rate parameters.
[0032] Although many variables may impact the location and specific dimensions of diffuser 100 , some general rules for determining 1) the width (W) of diffuser slot 104 and 2) the location of the centerline of diffuser slot 104 with respect to leading edge 120 of inducer 122 for embodiments of the present invention do exist. The width (W) is related to the vane or blade height of inducer 122 (or other bladed/vaned mechanism) at inlet 102 of diffuser slot 104 .
[0033] Specifically, W=(0.05 to 0.50)×(blade or vane height of inducer 122 at inlet 102 ). In one embodiment, W=(0.03 to 0.20)×(blade or vane height of inducer 122 at inlet 102 ). In general, the width should be small enough so as not to bleed an excessive amount of the flow from flow channel 103 . In the embodiments of the present invention contained herein, the loss in efficiency due to bleeding the flow is generally negligible due to the increase in overall equipment performance. The blade or vane height is the length of the blade or vane as measured from the surface of the impeller radially outward to the edge of the blade adjacent the sidewall of the housing.
[0034] The location of the centerline of diffuser slot 104 is also related to the size of the vane or blade of diffuser. The centerline of inlet 102 should typically be located along sidewalls 112 of housing 113 with respect to the span length of leading edge blade 122 and the location of leading edge 120 itself within flow channel 103 . More specifically, inlet 102 should be located a distance of up to ±70% of the blade or vane height of inducer 122 downstream or upstream of leading edge 120 , as measured parallel to axis 107 . A positive number means inlet 102 is located downstream of leading edge 120 and a negative number means inlet 102 is located upstream of leading edge 120 . Again, the blade or vane height is the length of the blade or vane as measured from the surface of the impeller radially outward to the edge of the blade adjacent the sidewall of the housing.
[0035] In addition to the design parameters delineated above, additional design parameters have also been developed in the course of refining diffuser 100 and other embodiments herein. First, in at least one embodiment of the present invention, it has been determined that diffuser slot 104 should typically have a radius ratio of greater than or equal to 1.03. The radius ratio is the radial extent at the exit of diffuser slot 104 , divided by the radius to inlet 102 . The radial extent at the exit of diffuser slot 104 is typically the distance from axis 107 to the termination of diffuser slot 104 . The radius to inlet 102 is typically the distance from axis 107 to inlet 102 . In another embodiment, the radius ratio ranged from about 1.03 to about 10. Substantially all slots included in the present invention will have a radius ratio according to the above.
[0036] Second, in at least one embodiment of the present invention, it has been determined that the flow entering diffuser slot 104 from flow channel 103 should typically range from about ½-2% to about 5-15% of the overall flow in flow channel 103 at the principal operating or design conditions. Inlet 102 and diffuser slot 104 are sized to achieve fluid flow within this range.
[0037] Finally, it is preferable that no vanes be incorporated within diffuser slot 104 . Diffusers having vanes have been found to increase difficulty of fabrication, increase difficulty of installation, increase inlet blockage and noise, and if poorly done, may increase distortion. Additionally, diffuser vanes would serve to break up the tip vortex rather than allow its full energy to be recovered through the unobstructed flow process of a vaneless diffuser. Likewise, other objects near inlet 102 such as labyrinth seals, other seals, bends, or other distortions to the passage would have the same adverse impact.
[0038] As mentioned above, the specific parameters related to the application requirements impact the specific dimensions and placement of diffuser 100 . In one embodiment of the present invention, designed for use in turbo pump applications with very high suction specific speed requirements, the dimensions of the inlet control aspects of diffuser 100 are as follows: a radial extent to the exit of diffuser slot 104 of 2.2″, a distance from the diffuser slot 104 centerline to leading edge 120 of inducer 122 of 0.3″, a diffuser slot 104 width of 0.2″, and an inlet 102 radius of 1.4″. Again, one skilled in the art will recognize that these dimensions will vary depending on the specific pumping application and the changes in the related parameters. However, the design parameters related to the sizing and location of the diffuser slot generally apply regardless of the specific application and for all embodiments described herein.
[0039] With reference to the arrows in FIG. 1, the operation of diffuser 100 will now be discussed. Flow from inlet plenum 130 enters flow channel 103 and flows toward hub 128 of impeller 124 . The flow enters inlet 102 of diffuser 100 and flows radially outward within diffuser slot 104 . In the embodiment illustrated in FIG. 1, diffuser 100 includes both one or more re-entry slots 108 and one or more return slots 110 . Flow from diffuser slot 104 next flows toward both re-entry slot 108 and return slot 110 . A portion of the flow from diffuser slot 104 flows into return slot 110 and radially outward to inlet plenum 130 . The remaining portion of flow from diffuser slot 104 flows into re-entry slot 108 . The flow exits re-entry slot 108 at an area within flow channel 103 directly upstream of inducer region 126 defined by inducer 122 , impeller hub 128 , and inducer leading edge 120 . The flow exiting re-entry slot 108 mixes with the flow entering flow channel 103 from inlet plenum 130 and continues onward toward hub 128 of impeller 124 . A substantial portion of the flow in flow channel 103 flows past inlet 102 of diffuser 100 and into inducer region 126 . This flow continues along the blades or vanes of inducer 120 and toward exit 134 of housing 113 . The flow exiting housing 113 typically passes through a vane 132 within housing exit 134 . Of course, in other embodiments, device 100 may include one or more re-entry slots 108 and no plenum return and/or exit slots 110 or vice versa.
[0040] As mentioned above, inlet 102 to diffuser slot 104 forms a substantially contiguous ring around inducer region 126 of channel 103 and is followed by a slot or channel of substantially radial design (diffuser slot 104 ) that provides a diffuser for the part-span vortex or other unstable flow which naturally migrates radially away from axis 107 due to its angular momentum. Substantially radial diffuser slot 104 has a length that is selected to provide effective diffusion and to appropriately raise the static pressure. By raising the static pressure, two-phase fluids at least partially containing vapor are collapsed and/or condensed back into single-phase fluids containing liquid. The higher static pressure causes the vapor bubbles in the vapor to compress. By including a substantially radial design and a clean inlet design (i.e., not tortuous path), the energy in the fluid drawn into diffuser slot 104 is conserved thereby increasing the efficiency of diffusion. Such a design allows for efficient diffusion and the ability take additional advantage of the fluid. An example of additional advantage includes discharging the diffuser effluent into the flow channel to help reduce instability in the flow channel.
[0041] FIGS. 2 - 4 illustrate alternative embodiments of the diffuser. The embodiment in FIG. 2 includes aspects that are identical to the embodiment in FIG. 1. Accordingly, some of the element numbers in FIG. 2 are identical to the element numbers in FIG. 1 for identical elements. However, in FIG. 2 multiple diffuser slots 104 , 136 , and 138 are present within sidewalls 112 of housing 113 . Diffuser slot 104 is located adjacent leading edge 120 of inducer 122 , diffuser slot 136 is located within impeller or inducer region 126 between leading edge 120 and housing exit 134 , and diffuser slot 138 is located adjacent housing exit 134 . Although not discussed with respect to FIGS. 2 - 4 below, the embodiments illustrated in FIGS. 2 - 4 generally include radius ratios as in FIG. 1 and are free of vanes as in FIG. 1.
[0042] Multiple diffuser slots may be used to bleed portions of flow channel 103 along various points within the channel. In addition to the reasons for bleeding flow adjacent leading edge 120 of diffuser 122 in the case of diffuser slot 104 , it may also be desirable to bleed the flow at other points downstream from leading edge 120 of inducer 122 . In FIG. 2, additional diffuser slots 136 , 138 are located downstream of diffuser slot 104 and leading edge 120 . In the case of diffuser slot 136 , where a shrouded impeller is used, diffuser slot 136 may be used to capture any shroud leakage flow. As for the diffuser slot 138 , it may be desirable to attempt to bleed off any remaining unstable flow such as impeller shroud leakage or system backflow prior to discharging the flow through housing exit 134 . It is contemplated that diffuser slots 136 , 138 will be configured in a manner similar to that of diffuser slot 104 and diffuser 100 . Although FIG. 2 illustrates the presence of three diffuser slots 104 , 136 , 138 , in at least one embodiment, there are only two diffuser slots. Other embodiments may include four or more diffuser slots. Embodiments including multiple diffuser slots may include any combination of slots or single slots in any locations illustrated in FIG. 2.
[0043] The flow through the embodiment illustrated in FIG. 2 is very similar to that in the embodiment illustrated in FIG. 1. However, as the flow continues within flow channel 103 past diffuser slot 104 , a portion of the flow may also be bled off into diffuser slot 136 . As with diffuser slot 104 , the flow entering diffuser slot 136 may be returned to flow channel 103 in an area of the flow channel upstream of diffuser slot 136 . The flow in diffuser slot 136 may also be returned to inlet plenum 130 or discharged to an area downstream of housing exit 134 . As in the case of both diffuser slot 104 and diffuser slot 136 , a portion of the flow will bypass both diffuser slots 104 and 136 and flow toward exit 134 of flow channel 103 . Prior to exiting flow channel 103 through exit 134 , an additional portion of the flow may be bled off into diffuser slot 138 . The flow entering diffuser slot 138 may be treated similarly to the flow bled off in diffuser slots 104 and 136 .
[0044] [0044]FIGS. 3 a - 3 d illustrate alternative embodiments of the diffuser slot of the present invention. In particular, FIGS. 3 a - 3 d are related to embodiments where at least one diffuser slot is located adjacent the exit of the housing. Because the housing exit configuration illustrated in FIGS. 3 a - 3 d is similar to those illustrated in FIGS. 1 - 2 , any elements in FIGS. 3 a - 3 d that are similar to elements in FIGS. 1 - 2 will be noted by the use of a similar element number having a prime symbol.
[0045] In FIG. 3 a , a portion of the flow exiting the housing is bled off into diffuser slot 138 ′thereby by-passing exit 134 ′. By locating diffuser slot 138 ′ on the outside of housing exit vane 132 ′, at least a portion of any vortex or other unstable flow will be captured by diffuser slot 138 ′. Vortex or other unstable flows are generally flows that are not collateral with the direction of the flow channel and the bulk of the flow field. The unstable flow captured in diffuser slot 138 ′ is then discharged into a diffuser configuration similar to any one previously mentioned herein, directly to the inlet plenum, or into an area downstream of housing exit 134 ′.
[0046] In FIG. 3 b , diffuser slot 138 ′ resides to the side of the housing exit vane 132 ′. However, unlike FIG. 3 a , the unstable flow captured in diffuser slot 138 ′ is returned to housing exit vane 132 ′ through exit return slot 140 . The flow mixes with the flow exiting the housing through housing exit vane 132 ′ and housing exit 134 ′. The by-pass flow from slot 138 ′ may also be injected into any corners of an exit channel to suppress corner stall.
[0047] The embodiment illustrated in FIG. 3 c is almost identical to that in FIG. 3 b with the exception that a diffuser slot 138 ″ is located on both sides of housing exit 132 ′ through exit return slots 140 . At least a portion of any unstable flow in the area to the sides of the housing exit vane will be captured in diffuser slots 138 ″ and returned downstream within housing exit vane 132 ′.
[0048] Structurally, the embodiment illustrated in FIG. 3 d is similar to that illustrated in FIG. 3 b . However, the sidewall of diffuser slot 138 ′″ that is in common with sidewall of exit housing vane 132 ′ includes exit return holes 142 . Any unstable flow captured within diffuser slot 138 ′″ may return to housing exit vane 132 ′ through exit return holes 142 and/or through exit return slot 140 . In one embodiment, the configuration in FIG. 3 d allows flow to be introduced into a hollow vane and exit through a cascade exit to achieve a blown flap control device.
[0049] [0049]FIG. 4 illustrates another alternative embodiment of the present invention. As in FIG. 3, any elements in FIGS. 4 that are similar to elements in other embodiments contained herein will be noted with a prime next to the element number. In FIG. 4, diffuser 100 ′ is virtually identical to diffuser 100 illustrated in FIG. 1. However, diffuser 100 ′ includes an additional slot. Particle capture slot 144 is used to capture particles (either solid or, in the pump case, entraining air or other non-condensing gases) from the flow exiting diffuser slot 104 ′ and lead them to a particle trap 146 . Particle capture slot 144 is typically an elongation of diffuser slot 104 ′. Particle slot 144 terminates in a generally rectangular cross-sectional area groove also known as particle trap 146 . Although not illustrated herein, additional passages or conduits that are in fluid communication with particle trap 146 may be included to allow the trap to be emptied as necessary. The remainder of diffuser 100 ′ is again virtually identical to diffuser 100 in FIG. 1.
[0050] In FIG. 4, flow enters flow channel 103 from inlet plenum 130 and is drawn toward impeller hub 128 by rotating impeller 124 and inducer 122 . At least a portion of the unstable flow enters inlet 102 ′ and flows radially outward from axis 107 ′ within diffuser slot 104 ′. Due to centrifugal forces, any particles within the flow will continue radially outward from diffuser slot 104 ′ into particle capture slot 144 and finally into particle trap 146 . The remainder of the flow will flow from diffuser slot 104 ′ into at least one of one or more reentry slots 108 ′ and one or more return slots 110 ′. The flow exiting slots 108 ′ and 110 ′ will continue in a manner similar to the flow in diffuser 100 , as illustrated in FIG. 1 and described in detail above.
[0051] Although the components that make up diffuser 100 of the present invention are generally described as slots herein, it is foreseeable that in other embodiments of the present invention various slots may be replaced by a plurality of holes or other orifices, a plurality of corresponding chambers, and/or a plurality of any other type of conduit (i.e., pipes, channels, grooves, etc.).
[0052] Although the illustrations contained herein are of an open inducer/impeller, it is contemplated that embodiments of the present invention may be used with either closed or open (i.e., shrouded or unshrouded) impeller/inducer configurations.
[0053] In another embodiment, an active diffuser slot is included instead of a passive diffuser slot. In the embodiments described above, the diffuser slot is passive in that it remains open at all times. An active diffuser slot may be configured to remain in a default closed position and only open when the pressure in the inducer region drops to a prescribed level.
[0054] In still another embodiment, a diffuser slot of the present invention may also be incorporated into the design of a hydroturbine. Hydroturbines work similar to pumps and compressors. However, the flow usually passes through the impeller in the reverse direction and work is extracted from the flow as opposed to work being done on the flow as in the case of a pump or impeller. For hydroturbines, all types of vortices are possible. By using a diffuser of the present invention to allow shroud bleed at the exit (or exducer) of the turbine, analogous to the inlet of radial pumps, it is likely that the overall performance of a hydroturbine will be improved.
[0055] The flow stabilizing device of the present invention including a novel diffuser slot offers advantages over prior art devices. By creating a diffuser slot having a clean inlet, a non-tortuous path, and a design related to the specific flow conditions, the device of the present invention maximizes the amount of energy in the fluid that is captured/recovered. In turn, this allows for a maximum pressure recovery (the change of kinetic energy to a static pressure rise). Maximizing pressure recovery offers at least two benefits to the overall operation of a system. First, for a cavitating flow, a greater pressure recovery helps ensure that substantially all two-phase fluid is converted back to single-fluid by collapsing and/or condensing any vapor bubbles in the fluid as it flows through the diffuser slot. Second, in a non-cavitating flow or in the case of vapor flow, maximizing the energy recovered in the fluid helps to ensure that a sufficient static pressure will exist to do gain additional benefits from the fluid. Additional benefits include re-injecting the fluid upstream or elsewhere in the system to help moderate the flow condition in the area of the re-injection. Moderation is achieved by either removing vortices in the flow to prevent corruption of upstream or downstream flow or by re-injecting to help reduce fluid rotation in the area of re-injection. Improving the upstream conditions of the fluid flow may allow the equipment and the system overall to operate more efficiently.
[0056] While the present invention has been described in connection with a preferred embodiment, it will be understood that it is not so limited. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims.
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The present invention is a device ( 100 ) for at least partially stabilizing an unstable fluid flow within a flow channel ( 103 ) by capturing at least a portion of the unstable fluid within a vaneless diffuser having a diffuser slot ( 104 ). The present invention also includes maintaining and harnessing a substantial portion of the energy contained in the fluid as it flows through the diffuser in order to utilize the fluid to improve the condition of the flow field. An example of a beneficial use includes discharging the diffuser effluent into the flow at other points critical to instability, hence reducing the overall instability of the flow channel.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a novel seam-forming apparatus for connecting building panels in a continuous seam along adjacent side edges of two building panels in the construction of a building or like structure.
2. Prior Art and Background
It is known to construct continuous arch metal buildings with adjacent curved building panels which are seamed together at their adjacent edges. See e.g., U.S. Pat. No. 3,902,288.
In connection with seaming panels for such metal buildings, rotary seamer devices have been used. Such a device is disclosed, for example in U.S. Pat. Nos. 3,875,642 (which is hereby incorporated by reference as if fully set forth herein); 4,470,186 and 4,726,107. The rotary seamer devices connect or seam together the side edge portions of adjacent panels.
Each panel comprises a main portion from which the side edge portion extends vertically. A first panel includes an out turned side edge portion having an upwardly extending, outwardly turned flange portion and a down-turned terminal portion forming an inverted U-shaped channel. In other words, the first section extends upwardly from the panel, the second section extends outward laterally from the first section and a third section extends downward from the second section. A second panel includes an in-turned side edge portion having an inwardly turned flange portion disposed inside the U-shaped channel of the first panel. This in-turned side edge portion has a first section extending upwardly from the panel and a second section extending laterally inward from the first section. These sections of the second panel fit within the first and second sections of the first panel respectively. Such an arrangement is described, for example, in U.S. Pat. Nos. 3,967,430 and 4,505,084.
The panels themselves are generally curved but a panel may have both straight and curved portions. These building panels are described in U.S. Pat. No. 5,249,445 which relates to a method for forming arched roof, vertical walled self-supporting metal buildings.
Seamers such as those described in U.S. Pat. No. 3,875,642 are only capable of seaming either straight panel portions or curved panel portions. Such seamers are not able to seam panels that are both straight and curved. When attempting to utilize such a seamer on panels with both curved and straight portions, the seaming apparatus tends to "walk off" or dislodge from the seam particularly in transition areas when the panel changes from straight to curved or vice-versa. The dislodging causes damage to the panel and/or an improper seam.
SUMMARY OF THE INVENTION
The apparatus of the present invention includes a seaming device having an intermediate set of rollers capable of moving vertically and thereby allowing the seamer to seam panels having both straight portions and curved portions. By allowing the intermediate rollers to move vertically, the seaming apparatus of the present invention "walks" along the panel much more easily and avoids causing damage to the paint of the panel. The vertical movement of the intermediate rollers permits the seamer to adjust to changes in the panel from straight to curved and curved to straight. The adjustment by the seamer prevents it from dislodging from the building panels, particularly in the transition regions where the panel changes from a straight to a curved portion.
The seaming apparatus of the present invention can be utilized to seam panels having both straight portions and curved corner portions with a corner radius as low as 4 feet and as high as infinity.
The seaming apparatus of the present invention is appropriate for use in the construction of a building having straight walls and a tightly arched corner radius and a fuller radius large arch. This type of building is typically referred to as a straight wall dome building. Typical gages of metal used in the panels to form such a building are 0.025 to 0.045 structural quality, prepainted, galvanized steel. Typical spans of such structures range from 12 feet to 80 feet.
Another typical building panel of the type for which these seaming apparatus of the present invention are particularly suited consists of straight walled portions, tightly arched radius portions and a straight slanted portion having a very tight apex arched portion at the top. Buildings constructed with these shape panels are commonly referred to as a gable-type building having relatively straight sloping roof panels. The typical spans for buildings of this type are 12 feet to 80 feet using 0.025 to 0.045 structural grade, prepainted, galvanized steel.
In another aspect of the present invention, the intermediate rollers are mounted using hardened bearings which provides for smooth and trouble-free operation and a longer life for the seaming apparatus.
Other aspects, advantages and capabilities of the present invention will become apparent to those of ordinary skill in the art upon reviewing the following detailed description in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of seaming apparatus embodying features of the present invention;
FIG. 2 is a fragmentary perspective view showing the arrangement of rollers in relation to two building panels being joined;
FIG. 3 is a fragmentary perspective view showing the arrangement of the rollers in relation to two curved building panels being joined;
FIG. 4 is a detailed view of the front upper and lower power driven embodying aspects of the present invention;
FIG. 5 is a detailed view of the intermediate horizontally opposed rollers; and
FIG. 6 is a detailed view of the rear upper and lower power driven rollers embodying aspects of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a partial section and side elevation view of a seaming apparatus embodying aspects of the present invention. The seam-forming apparatus, generally indicated as 10, is comprised of a main support frame 12, a power source in the form of an electric gear motor 14 mounted on the support frame 12 and a panel-engaging assembly generally in the form of three sets of rollers. The three sets of rollers include upper power driven roller 16 and lower power driven roller 18, a second set of upper power driven roller 20 and lower power driven roller 22 axially spaced from the first set and a third intermediate set of laterally spaced (horizontally opposed) rollers 24 and 26 disposed between the other two sets. The electric motor 14 is coupled to the two sets of power driven upper and lower rollers in the normal manner via a gear and chain drive train designated generally as 28.
The upper power driven rollers 16 and 20 guide the seamer as it moves forward. The two bottom power driven rollers (also referred to as bottom drive rollers) 18 and 22 grip the panel in combination with the forming rollers 16 and 20 and drive the seamer along. The pair of horizontally opposed rollers 26 and 24 are the initial forming set of rollers and are capable of moving vertically along their axles independent of the other rollers.
In FIG. 2, the edge portions of two building panels designated generally as 28 and 30 are shown. Building panel 28 includes a vertical portion 36, an outturned flange portion (horizontal portion) 38 and a down turned terminal portion (vertical edge) 40 which in combination form a U-shaped channel. Building panel 30 includes a vertical portion 32 and a top horizontal portion that is doubled over and is placed within the U-shaped channel prior to the seaming operation. Generally speaking, the seaming process involves turning vertical edge 40 under inturned flange portion (top portion) 34 to form a tight seam.
Each of the bottom drive rollers 18 and 22 are mounted for vertical adjustment relative to their associated upper roller 16 and 20 respectively. The bottom drive rollers are so mounted in a nearly identical manner. For purposes of brevity, only the mounting of the forward bottom drive roller 18 will be described. Bottom drive roller 18 is mounted using vertically adjustable bearing block in a well known manner utilizing slide rods 70 and 72 held apart by plate 74 (see FIG. 1). The lower ends of the slide rods being affixed to a bearing block (not shown) to which the roller 18 (22) is mounted by a shaft 42 (62). Threaded adjustment bolt 76 is threaded through plate 74 with the lower end of the adjustment bolt 76 resting against the main support frame (see FIG. 1). As the adjustment bolt 76 is turned in one direction, the bottom roller is raised and as the adjustment bolt 76 is turned in the other direction, the bottom roller is lowered.
To begin the seaming process utilizing the present invention, the seaming apparatus 10 is mounted in the normal manner on the panels to be seamed. After mounting the seaming apparatus 10, the bottom drive roller 18 is in firm frictional contact with the bottom side of the doubled over top portion 34 of panel 28. The bottom drive roller 18 is mounted to the main support frame 12 via a shaft 42. Upper forming roller 16 which guides the seamer along the seam being formed is also rotatably mounted to the main support frame 12 via a shaft 44.
Horizontally opposed roller 26 rides over horizontal edge 38 and vertical portion 36 (see FIG. 5). Horizontal roller 24 performs the major forming action upon vertical edge 40. Contact between horizontal roller 24 and vertical edge 40 forces vertical edge 40 inward towards vertical portion 36 essentially beginning the seaming process. Horizontal roller 24 is mounted to main support frame 12 via shaft 46. Bearing 86 (see FIG. 5) permits horizontal roller 24 to freely move in the vertical direction. Bearing 48 is encapsulated by bearing shim 50 and 52. Similarly, horizontal roller 26 is coupled to main support frame 12 via shaft 54. Horizontal roller 26 can move freely in the vertical direction upon bearing 80 which is encapsulated by bearing shims 58 and 60 (see FIG. 5).
In addition, horizontal roller 24 preferably includes a laterally movable axis arrangement as is described, for example, in U.S. Pat. No. 3,875,642. This arrangement allows roller 24 to be moved to an open position for ease of mounting the seaming apparatus on the panels and a closed position for the seaming process.
FIG. 5 is a cut-away view taken along line V--V of FIG. 3 showing the horizontal rollers. The basic task of horizontal roller 26 is to ride the outside edge of vertical portion 36 to ensure that the seaming apparatus does not dislodge from the building panel. In addition, horizontal roller 26 can move vertically upward and is rotatably mounted to shaft 54. Roller 26 rotates through the combination of needle-bearing 80 which rotates about hardened inner ring 82. The needle roller-bearing 80 has a natural rolling motion which permits it to slide vertically upward along the hardened inner ring 82. When the seamer comes in contact with the portion of the panel having a tight radius of curvature, horizonal roller 26 is forced vertically upward by horizontal edge 38. Horizontal roller 26 then moves vertically upward against shim 58 which then causes needle-bearing 56 to come into rotation in shim 60 which limits the upward travel of roller 26.
Shim 96 pushes against needle bearing 97 and rides against shim 98 which is held in position by washer 85 and 99. The foregoing combination limits the downward vertical movement of roller 26.
Horizontal roller 24 can similarly move vertically on shaft 46. Needle bearing 84 allows the roller to move vertically on inner ring 86. Washer 88 has a set of bearings 90, 92 and 94 which operate in the same fashion as bearings 60, 56 and 58. Upward vertical movement of roller 24 is limited by contact with shim 50 which rotates needle bearing 48 which is held by shim 52. That combination of bearings allows the roller to rotate freely upon shaft 46 even at the extreme ends of its vertical travel without jamming or causing any damage to the shaft.
The seaming process is completed with the use of forming roller 20 and bottom drive roller 22. Forming roller 20 is rotatably mounted to the main support frame 12 via shaft 60. Bottom drive roller 22 is rotatably mounted to the main support frame 12 via shaft 62. Bottom drive roller 22 compresses vertical edge 40 flat against top portion 34, thereby completing the seaming process as the seaming process travels in the direction indicated by the arrow in FIG. 2. The outer surface 23 of bottom drive roller 22 essentially compresses vertical edge 40 and top version 34 against the inner surface 21 of forming roller 20.
FIG. 3 is similar to FIG. 2, but shows the rollers on a curved portion of the panels. On the curved portion of the panels, the horizonal rollers 26 and 24 can be seen to have moved vertically upward to account for the portion of the arch of the panels between the points defined by the forward set of rollers 16 and 18 and the rearward set of rollers 20 and 22. Roller 24 has moved vertically upward pushing shim 50 into bearing 48 which is held by shim 52. This movement of roller 24 allows the building panels to be seamed on a portion with a tight radius without causing any damage to the panel such as tearing or cracking of the portions of the panels being seamed or scratching of the paint. Roller 26 has also moved vertically upward which moves against shim 58 into bearings 56 which are held by shim 60. The vertical motion of rollers 24 and 26 is controlled by the panels themselves, particularly horizontal edge 2, vertical edge 3 where they come into contact with the two rollers.
FIG. 4 is a cross-sectional view taken along a section of line IV--IV shown in FIG. 3. Forming roller 16 surrounds horizontal edge 38 and thereby guides the seaming machine along the panels. Bottom roller 18 is a gripper roller which grips top portion 34 and horizontal edge 38 against the inner portion 17 of top roller 16. Bottom roller 18, which is driven by motor 14, propels the seaming apparatus along the panel.
FIG. 6 shows the final step of the seaming process. Rollers 20 and 22 operate in a manner nearly identical to that of rollers 16 and 18. Bottom roller 22 comes into contact with vertical edge 40 which was previously bent partially upward towards horizontal edge 38 by horizontal roller 24. Bottom roller 22 forces vertical edge 40 into contact with the top portion of 34 thereby encapsulating the seam.
Although the present invention has been described to a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example and that changes of details of structure and operation may be made without departing from the spirit of the present invention.
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A seaming device for connecting building panels in a continuous seam along adjacent side edges of two building panels in the construction of a building or like structure which is particularly suited for seaming panels with both curved and straight portions. The seaming device includes an intermediate set of rollers capable of moving vertically and thereby allowing the seamer to seam panels having both straight portions and curved portions. By allowing the intermediate rollers to move vertically, the seaming apparatus of the present invention "walks" along the panel much more easily and avoids causing damage to the paint of the panel. The vertical movement of the intermediate rollers permits the seamer to adjust to changes in the panel from straight to curved and curved to straight.
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BACKGROUND
[0001] 1. Field
[0002] The present invention relates generally to collapsible canopy shelters and more specifically to collapsible canopy shelters with reinforced eaves, an adjustable ventilation system, and spring loaded pull latches.
[0003] 2. Background
[0004] Many tents and canopy shelters with collapsible. frames exist. These structures are commonly used to provide portable shelter for outdoor activities such as camping, picnicking, parties, weddings, and more. Such collapsible canopy shelters typically comprise a canopy cover and a canopy frame configured to stand alone when in an assembled position and to collapse into a compact position for storage and transport.
[0005] While conventional collapsible canopy shelters are useful for a variety of purposes, such as providing portable shade and/or shelter from the elements and providing an aesthetically pleasing backdrop for special events, conventional canopy frames lack structural integrity. As a result, they are vulnerable to severe weather and human or animal interference and are prone to bow or sag.
[0006] In addition, the support poles of conventional canopy frames typically have unreliable latches that stick when the user attempts to assemble or collapse the shelter. Moreover, traditional spring-pin latches, or latches comprising a retractable spring pin that the user pushes inward to release, are temperamental to use and can pinch the user's hands and fingers when he or she attempts to assemble or collapse the shelter.
[0007] Moreover, conventional canopy covers do not allow for adjustable ventilation. They either have no ventilation at all and trap unwanted heat during warm weather, or alternately, they have permanent screens or vents that vent much needed warm air during cool weather. There is therefore a need in the art for a collapsible canopy shelter having a frame with greater structural rigidity and stability and robust, easy to use pull latches, as well as an adjustable ventilation system.
SUMMARY
[0008] Embodiments disclosed herein address the above stated needs by providing a collapsible canopy shelter with reinforced eaves to provide greater structural integrity. The technology of the present application also features a collapsible flap capable of moving between a closed and an open position to ventilate air from the collapsible canopy shelter when desired. Another aspect of the technology of the present application includes a sliding, spring-loaded pull latch to lock the eaves in an assembled position.
[0009] The foregoing, as well as 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 DRAWINGS
[0010] FIG. 1 shows a front plan view of one embodiment of a canopy frame for a collapsible canopy shelter;
[0011] FIG. 2 shows a side plan view of one embodiment of a sliding eave mount slidably coupled to an upwardly extending pole and fixably coupled to the first left cross member;
[0012] FIG. 3 shows a sectional view of one embodiment of the sliding eave mount shown in FIG. 2 with the latch in the locked position;
[0013] FIG. 4 shows a sectional view of the embodiment of the sliding eave mount shown in FIG. 2 with the latch in the unlocked position;
[0014] FIG. 5 shows a partial side plan view of one embodiment of the canopy frame and the canopy cover having at least one collapsible flap supported by a pivoting support;
[0015] FIG. 6 shows a side plan view of one embodiment of the pivoting support in the open position;
[0016] FIG. 7 shows a side plan view of the pivoting support shown in FIG. 6 in the closed position;
[0017] FIG. 8 shows a side plan view of another embodiment of a pivoting support in the open position;
[0018] FIG. 9 shows a side plan view of the embodiment of the pivoting support shown in FIG. 8 in the closed position; and
[0019] FIG. 10 shows a front plan view of one embodiment of a fulcrum.
DETAILED DESCRIPTION
[0020] The technology of the present application will be further explained with reference to FIGS. 1 through 10 . FIG. 1 shows a front plan view of one embodiment of a canopy frame 10 for a collapsible canopy shelter. In this embodiment, canopy frame 10 comprises a plurality of eaves 12 linking a plurality of upwardly extending poles 14 . Each eave 12 may comprise a series of pivotally coupled scissor-jacks 18 1-n . Each scissor-jack 18 1-n may include a left cross member 20 1-n and a right cross member 22 1-n , crossed and pivotally coupled at a cross point 24 . To provide additional rigidity to improve the structural integrity of canopy frame 10 , two reinforcing cross members 26 may be crossed and pivotally coupled to left cross members 20 1-n and right cross members 22 1-n at each intersection 28 of scissor-jacks 18 1-n . All pivoting joints may be pinned, bolted, riveted, joined by rotational fasteners, or otherwise rotatively connected as is known in the art.
[0021] Each eave 12 may be collapsibly coupled to a pair of upwardly extending poles 14 through two fixed eave mounts 30 and two sliding eave mounts 32 . Fixed eave mounts 30 may be fixably coupled to the top ends 34 of upwardly extending poles 14 , and sliding eave mounts 32 may be slidably coupled to poles 14 , such that sliding eave mounts 32 slide over the length of upwardly extending poles 14 from the bases 36 of poles 14 to just below fixed eave mounts 30 . In turn, a first left cross member 20 1 and a final right cross member 22 N may be pivotally coupled to sliding eave mounts 32 while a first right cross member 22 1 and a final left cross member 20 N may be fixably coupled to fixed eave mounts 30 , allowing scissor-jacks 18 1-N to collapse in a manner similar to the compression of an accordion when one or more of sliding eave mounts 32 are released and slid in a downward direction denoted by arrow A.
[0022] Of course, one of ordinary skill in the art will readily understand that several alternative mechanisms could be used to collapsibly couple eaves 12 to upwardly extending poles 14 . For example, eaves 12 could be coupled to upwardly extending poles 14 through locking channel systems or a quick release for scissor-jacks 18 1-N , as is generally known in the art.
[0023] FIG. 2 shows a side plan view of sliding eave mount 32 slidably coupled to upwardly extending pole 14 and fixably coupled to first left cross member 20 1 . In this embodiment, sliding eave mount 32 may comprise a sliding body 38 , a plurality of arms 40 to fixably attach to eaves 12 , and a latch 42 . In further detail, latch 42 may comprise a spring-loaded lever 44 with a locking pin 46 that is pivotally coupled to sliding body 38 through a hinge pin 48 that may be press fit into sliding body 38 . A torsion spring 50 ( FIGS. 3 , 4 ) may encircle hinge pin 48 , such that a first leg 52 and a second leg 54 of torsion spring 50 compress when lever 44 is pulled in the direction of arrow B. Lever 44 and locking pin 46 may be configured to allow locking pin 46 to mate with a pin hole 56 located in upwardly extending pole 14 when latch 42 and locking pin 46 are slid into alignment with pin hole 56 .
[0024] FIGS. 3 and 4 show sectional views of one embodiment of sliding eave mount 32 with latch 42 in the locked and unlocked positions, respectively. To unlock latch 42 , a user may swivel latch 42 in the direction of arrow C, thereby withdrawing locking pin 46 from pin hole 56 and compressing torsion spring 50 . As a result, sliding eave mount 32 may slide in a downward direction along upwardly extending pole 14 ( FIG. 1 ) and allow eave 12 to collapse as upwardly extending pole 14 is moved inward towards the remaining upwardly extending poles 14 .
[0025] To lock latch 42 , a user may slide sliding eave mount 32 upward into alignment with pin hole 56 . Once in alignment, torsion spring 50 automatically pivots latch 42 in the direction of arrow D ( FIG. 4 ), thereby snapping locking pin 46 into pin hole 56 and locking sliding eave mount 32 into an assembled position. While described as a torsion spring here, other elastically deformable devices are possible, including, for example, helical or coil springs, leaf springs, or the like. These deformable devices may be formed of spring metals such as music wire or metal alloys, plastics, composites, or any other suitable material known in the art.
[0026] To ventilate air from the collapsible canopy shelter, one embodiment of the collapsible canopy shelter may include at least one. collapsible flap that may be opened and closed as desired. FIG. 5 shows a partial side plan view of one embodiment of canopy frame 10 having a cover support member 73 , as well as a canopy cover 60 having at least one collapsible flap 62 supported by a pivoting support 70 , 100 ( FIGS. 9 , 10 ). To ventilate air from beneath canopy cover 60 , pivoting support 70 , 100 may be used to pivot collapsible flap 62 in the direction of arrow E. into an open position. Alternately, collapsible flap 62 may be pivoted in the direction of arrow F into a closed position to prevent air flow. One of ordinary skill in the art will readily understand that a user may also position collapsible flap 62 in any intermediate position between the open and closed positions.
[0027] In further detail, FIGS. 6 and 7 show side plan views of one embodiment of pivoting support 70 in the open and a closed positions, respectively. In this embodiment, pivoting support 70 may comprise a cantilever 72 attached to collapsible flap 62 through a set of cover straps 63 or any other means of attachment generally known in the art, including, for example, a sheath formed of canopy material, snaps, VELCRO®, and the like. Cantilever 72 may also be pivotally coupled to cover support member 73 through a fixed fastener 74 and an adjustable fastener 76 , each of which may intersect cover support member 73 and cantilever 72 along an axis that is perpendicular to cantilever 72 . Fixed fastener 74 may be set at a fixed height y and held in position by a nut 78 . Adjustable fastener 76 may comprise a handle 80 and be threaded into a threaded receiving hole 82 in cantilever 72 , such that rotating handle 80 in a first direction pivots cantilever between the closed position and the open position in the direction of arrow G, and rotating adjustable fastener in a second, opposite direction pivots the cantilever between the open position and the closed position in the direction of arrow H.
[0028] A first flexible spacer 84 may encase fixed fastener 74 between a top surface 86 of cover support member 73 and a bottom surface 88 of cantilever 72 , while a second flexible spacer 90 may encase adjustable fastener 76 between a top surface 86 of cover support member 73 and a bottom surface 88 of cantilever 72 . First and second flexible spacers 84 , 90 stabilize cantilever 72 and allow it to pivot between the closed and open positions in response to the rotation of adjustable fastener 76 . Flexible spacers may be formed of rubber or any other suitable elastic material with a density sufficient to withstand the downward force exerted by the weight of cantilever 72 and collapsible flap 62 .
[0029] Fixed fastener 74 and adjustable fastener 76 may consist of a variety of rotational fasteners, including, for example, screws, bolts, adjustable pins, or any other suitable fastener as is generally known in the art Optionally, pivoting support 70 may further comprise a sleeve 92 . Sleeve 92 may provide aesthetic benefits as well as protect cover support member 73 from exposure to light and moisture at the points where it has been drilled to accommodate fixed fastener 74 and adjustable fastener 76 .
[0030] FIGS. 8 and 9 illustrate side plan views of another embodiment of pivoting support 100 in the open and closed positions, respectively. Pivoting support 100 may comprise a cantilever 102 that is attached to cover support member 73 in the same manner discussed with respect to cantilever 72 above. Moreover, cantilever 102 may be pivotally coupled with cover support member 73 through a pivoting bracket 104 located at a pivot point 105 . Pivoting bracket 104 may be offset a distance x from a pivot end 106 of cantilever 102 , such that pivot end 106 serves as a hard stop to prevent cantilever 102 from rotating beyond the open position shown in FIG. 8 . In addition, a fulcrum 108 may be slidably coupled to cover support member 73 such that it restrains cantilever 102 when in the closed position and props cantilever 102 when in the open position or any position between the closed and open positions.
[0031] FIG. 10 shows a front plan view of one embodiment of fulcrum 108 . In this embodiment, fulcrum 108 may comprise a cantilever hole 110 sized to frictionally engage cantilever 102 when cantilever 102 is in the closed position shown in FIG. 9 . Fulcrum 108 may further comprise a roof support hole 112 configured to slidably engage with roof support member 73 , such that it props cantilever 102 when in the open position shown in FIG. 8 . Of course, one of ordinary skill in the art will readily understand that fulcrum 108 may prop cantilever 102 in any intermediate position between the closed and open positions to provide varying levels of air flow. Cantilever 102 , bracket 104 , and fulcrum 108 may be formed of metal, plastic, or any other material of suitable strength as is generally known in the art.
[0032] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
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The technology of the present application provides a collapsible canopy shelter having reinforced eaves for additional structural integrity, as well as at least one collapsible ventilation flap in the canopy cover that is capable of moving between a closed position and an open position to ventilate air from beneath the canopy cover as desired. Further, the collapsible canopy shelter comprises a canopy frame with a robust, spring-loaded pull latch, allowing the user to quickly and easily assemble and collapse the shelter without risking injury.
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This is a division of application Ser. No. 000,741 filed Jan. 6, 1987, now U.S. Pat. No. 4,748,082.
BACKGROUND OF THE INVENTION
The invention is directed to zeolite molded articles, e.g., castings, a method of producing them and their use in heat accumulators.
It is known that zeolites can be used in heat accumulators (German-OS No. 33 12 875).
It is also known that zeolite molded blanks can be used in heat accumulators which are adapted to the heat exchanger surfaces and contain flow conduits (German-OS No. 32 07 656).
The use of molded zeolite blanks containing a fine-meshed metal fabric in heat exchangers is also known (German-OS No. 33 47 700).
Furthermore, drying elements of zeolite are known which are provided with a gas-permeable casing of glass, ceramics, porcelain, plastic or metal (European-OS No. 140 380).
The known molded articles have substantial disadvantages due to the metal fabrics. Thus, the metal fabric is difficult to work into the zeolite mass. It is not possible to homogenize with the zeolite binder mixture in known mixing devices. Metal fabrics are expensive to manufacture. They are relatively heavy and result in the formation of tears and breaks in the zeolite molded article on account of the different coefficients of expansion.
The metal fabric has the further disadvantage that it corrodes upon contact with the water.
There was thus the task of producing zeolite molded articles for use in heat accumulators or sorption devices which are formed in accordance with the dimensions of the heat accumulator device and which are sufficiently strong and exhibit a uniform coefficient of expansion.
SUMMARY OF THE INVENTION
The invention is directed to zeolite molded articles which contain alkali silicate, e.g., sodium silicate or potassium silicate and/or alkaline earth silicate, e.g. calcium silicate or magnesium silicate mineral fibers and/or carbon fibers in addition to zeolite.
The zeolite molded articles, e.g., castings of the invention can have a platelike geometry, preferably that of flat bodies with square or round boundaries with edge lengths or equivalent diameters of 1 mm to 500 mm, preferably of 10 mm to 500 mm and a thickness of 1 mm to 30 mm, preferably of 4 mm to 25 mm.
The zeolite moldings can have a surface which corresponds to the intended use, such as, for example, a structured surface. The surface structures can be indentations such as, for example, waffle patterns and profiled flow conduits of any geometry, such as is customary in plate heat exchanger plates, as well as hollow space structures such as honeycomb bodies or block heat exchangers. They can be produced, for example, by positioning perforations or conduits in a triangular or rectangular distribution with perforation or equivalent conduit diameters of 0,2 to 1.2 times the thickness of the zeolite moldings, preferably 0,8 to 1.1 and with a perforation or conduit distribution of 1.2 to 2.5 times the perforation or equivalent conduit diameter, preferably 1.4 to 2.0.
The shaping of the zeolite molding, e.g. casting can be carried out by means of a suitable pressing apparatus. The surface structure can be obtained both by the pressing as well as by mechanical working.
The shaping can occur by means of an isostatic or uniaxial pressing in the range of 0.1 MPa to 50 MPa, preferably in the range of 0.1 to 30 MPa as a function of the shape and the size of the zeolite casting. The amount of pressure applied can be held constant for a time of 0 seconds to 20 minutes, preferably less than 10 minutes.
The invention is also directed to a method of producing the zeolite molded articles which comprises mixing powdery zeolite with alkali silicate and/or alkaline earth silicate, such as, for example, sodium silicate, and water; mineral fibers and/or carbon fibers are mixed in, the mixture obtained is pressed and gradually dried with rising temperatures until a constant weight and activated.
The zeolites used can be zeolites of the A, X or Y type, optionally in their form replaced with Na.sup.⊕, Mg.sup.⊕⊕ or Ca.sup.⊕⊕ ions. In a preferred embodiment of the invention there can be used zeolite A replaced with Mg⊕⊕ ions.
The mineral fiber used can be triton kaowool, for example.
The alkali silicate or alkaline earth silicate, especially sodium silicate, which is added as binder can have a module of 2.0 to 3.7, preferably 3.0 to 3.7.
The amount of mineral fibers or carbon fibers in the mixture can amount to 0.1 to 15 percent by weight, preferably 0.5 to 5 percent by weight in relation to the zeolite/water/alkali silicate or alkaline-earth silicate.
The mixture water glass (as g SiO 2 +g Na 2 O) : zeolite (bone-dry): water: fiber can assume any value within a range of (7-29.5):100: (12-73):(0.2-28). The mixture preferably has the composition (18-29):100:(60-70):(0.2-9.5).
The zeolite molded article can be substituted before the drying, before the activation and/or after the activation with the specified cations. Insoluble alkaline-earth silicate can be formed from alkali silicate at the substitution of the zeolite molded articles with alkaline-earth ions.
The zeolite molded article can be dried first at temperatures of 20-39° C., whereby the CO 2 content of the drying air is set to less than 200 ppm, subsequently optionally in a second drying state at temperatures of 40°-120° and optionally in a third drying state at 121°-200° C. under conditions which are otherwise identical.
The third zeolite molded article is activated at temperatures of 650° at the most.
These zeolite molded articles of the invention are advantageously easy to produce. They are inexpensive and corrosion-proof. Since the mineral fibers as well as the zeolite consists primarily of SiO 2 and Al 2 O 3 , the coefficient of expansion is of comparable magnitude. Therefore, thermally induced fissures and breaks can not occur in the zeolite molded articles of the invention.
The zeolite molded articles of the invention can be used with preference for the absorption of water. Depending on the initial zeolite used, the zeolite molded articles of the invention can also adsorb larger molecules.
It is also advantageous that the zeolite castings of the invention after they are completed are able to be worked with customary tools (e.g. saws, boring machines). Thus, special flow conduits can be worked into the heat exchanger during installation prior to delivery to the site. This is not possible when metal mesh is used, since tears or frayed areas can develop at the cut or drilled edges.
The composition can comprise, consist essentially of or consist of the stated materials and the process can comprise, consist essentially or consist of the recited steps with such materials.
Unless otherwise indicated all parts and percentages are by weight.
DETAILED DESCRIPTION
EXAMPLE 1
8.5 kg zeolite Na--A (water content 19.5 percent by weight) are mixed with 3.2 liters waterglass (sodium silicate) (module 3.7: =1.25 g/m 3 ) and 0.24 liters H 2 O for approximately 30 min. Then, 382 g (3%) mineral fibers are mixed in. Castings are produced from the mixture according to the following conditions.
a. Size of the briquettes: 150×150 mm
b. Thickness: 4 mm
c. Pressing time: 10 min.
Variation: Amount of pressure applied
d. First drying: 20° C.
Second drying: 50° C.
Third drying: 110° C. until a constant weight each time
e. Activation: 450° C.
______________________________________ Water absorption (equilibriumPressure (MPa) load 80% rel. humidity)______________________________________0.1 15.810.3 15.017.2 15.725.7 18.940.0 12.7______________________________________
EXAMPLE 2
Mixtures are prepared according to Example 1 with the difference that instead of Na--A zeolite, ion-replaced zeolites of the MgA, CaA, MgX, MgY types are used. In order to produce the ion-replaced zeolites of the MgA type, 10 kg zeolite Na--A are suspended in 19.5% Mg (NO 3 ) 2 solution for 2 hours at 40° C., filtered and washed free of NO.sub. 3. The filter cake is dried at 105° C. in a drying cabinet and subsequently ground.
An aqueous Ca(NO 3 ) 2 solution is used in an analogous manner to produce the zeolite Ca--A.
Zeolites of the MgX and MgY types are produced by working according to the directions given above and using 10 kg NaX zeolite (20 percent by weight H 2 O) or 10 kg NaY zeolite (21 percent by weight H 2 O) instead of 10 kg NaA zeolite. The processing is carried out according to Example 1.
Amount of pressure applied 25 MPa
Activation 650° C.
______________________________________ Water absorption (equilibriumType load 80% rel. humidity)______________________________________MgA 19.6CaA 19.2MgX 17.4MgY 16.8NaA 18.9______________________________________
EXAMPLE 3
6.8 kg zeolite Na--A (bone dry) are mixed with 1.0 liter waterglass (sodium silicate) (module 3.7,ρ=1.25 g/m 2 ) and homogenized; then 480 g mineral fibers are worked in.
Variation: Size of the briquettes 1 ×1 mm to 500×500 mm
Pressure: 8MPa
Thickness: 5.2 mm
Pressing time: 20 min.
First drying: 39° C.
Second drying: 120° C. to constant weight
Activation: 500° C.
______________________________________ Water absorption (equilibriumEdge Length load 80% rel. humidity)______________________________________ 1 mm 18.7 10 mm 18.9100 mm 19.8250 mm 18.9500 mm 19.0______________________________________
EXAMPLE 4
6.8 g zeolite NaA (bone dry) are mixed with 4.0 liters waterglass (sodium silicate) (module 2.0ρ=1.25 g/m 3 ) and homogenized; then, 13 g mineral fibers are worked in.
Shape: 100 mm diameter
Pressing time: 5 min.
Pressure: 17 MPa
Variation Thickness of the briquettes
First drying: 20° C.
Second drying: 85° C.
Third drying: 125° C.
Activation: 480° C.
______________________________________ Water absorption (equilibriumThickness load 80% rel. humidity)______________________________________ 1 mm 15.7 4 mm 15.510 mm 12.225 mm 11.530 mm 10.8______________________________________
EXAMPLE 5
8.5 kg zeolite (20% H.sub. 2O) are mixed with 4 liters waterglass (sodium silicate) (module 2.0.ρ=1.25 g/cm 3 and homogenized. Then, 1900 g mineral fibers are worked in.
Shape: 5 mm diameter
Pressure: 8 MPa
Thickness: 4 mm
Variation: Pressing time
______________________________________ Water absorption (equilibriumTime load 80% rel. humidity)______________________________________0.1 sec. 14.91 min. 15.25 min. 15.210 min. 16.020 min. 14.0______________________________________
EXAMPLE 6
8.5 kg zeolite MgX (20% H 2 O) are homogeneously mixed with 1 liter waterglass (sodium silicate) (module 2.0=1.25 g/m 3 ) and 1.5 liter H 2 O. Then, 700 g mineral fibers are worked in. The molded articles are produced in accordance with Example 1 and activated.
The activated molded articles are provided with bores having a diameter of 1.4 mm to 2.0 mm.
______________________________________Water absorption (equilibrium load80% rel. humidity) bores______________________________________16.5% 1.4 mm16.2% 1.7 mm16.8% 2.0 mm______________________________________
EXAMPLE 7
8.5 kg zeolite NaA (20% H 2 O) are homogenized with 1 liter waterglass (sodium silicate) (module 3.7,ρ=1.25 g/m 2 and 1.5 liters water. Then, 17 g mineral fibers are worked in.
The molded articles are pressed in accordance with example 1 at pressures of 25.7 MPa and subsequently after treated according to Example 1. Conduits 2 mm deep and 5 mm wide are milled in at intervals of 10 mm. The water absorption (80% rel. humidity to equilibrium load) is 19.5 percent by weight.
EXAMPLE 8
A mixture is produced in accordance with Example 1. The pressed zeolite blanks are divided into 3 groups:
Group A is treated before the drying with aqueous CaCl 2 solution (1 liter 2 moles CaCl 2 per zeolite molded article; 1 hour room temperature).
Group B is treated after the drying in accordance with Example 4 with aqueous CaCl 2 solution (1 liter 2 moles CaCl 2 per zeolite molded article, 1 hour 60° C.).
Group C is treated after activation in accordance with Example 2 with aqueous CaCl 2 solution) 1 liter CaCl 2 per zeolite molded article, 2.0 hours 80° C.).
Then, all zeolite blanks are dried in accordance with Example 5 and activated.
______________________________________ Degree of Water Absorption enhancement (equilibrium loadGroup mole % 80% rel. humidity)______________________________________A 22.5 17.9B 19.5 16.5C 18.5 16.8______________________________________
The entire disclosure of German priority applicaiton No. P3600628.9 is hereby incorporated by reference.
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There are prepared zeolite molded articles which also contain alkali silicate and/or alkaline earth silicate and mineral fibers and/or carbon fibers in addition to the zeolite.
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TECHNICAL FIELD
This invention relates to electrical switches and circuit breakers, and more particularly to a switchable circuit breaker.
BACKGROUND OF THE INVENTION
Circuit breakers are used in electric and electronic systems in which components must be protected from abnormal current conditions.
A typical circuit breaker using a tripping mechanism of the bimetallic type is described in U.S. Pat. No. 4,363,016 to Unger. In this known device a rocker button is provided for resetting the tripped circuit breaker. However, there is no possibility of manually switching the contacts from an "ON" to an "OFF" condition.
A unitary switch and circuit breaker is disclosed in U.S. Pat. No. 4,833,439 to Bowden et al. In this known device a rocker has a projecting arm to directly act on a bimetallic breaker strip for manually closing or opening a pair of contacts. In this case, the contacts have to be disposed close to the rocker side of the circuit breaker housing in order to render a direct actuation by the rocker possible. That may produce insulation problems due to the short distance between the contacts carrying large currents and the hand actuated rocker. Another problem may result from the fact that in this known device the closing or opening speed of the contacts when being switched corresponds directly to the rotational speed of the rocker. A slow or incomplete actuation of the rocker may result in a slight touching of the contacts or in an incomplete contact closing which may produce an undesirable arcing, while the rocker returns to its start position (so-called "teaseability").
SUMMARY OF THE INVENTION
It is thus an object of the present invention to overcome the aforesaid defects of the existing art.
It is another object of the present invention to provide a unitary switch and circuit breaker having a small number of components and being compact and small in size, in particular concerning height and width.
It is a further object of the present invention to provide a switchable circuit breaker that can be used to perform both the switching function and the circuit breaker function.
It is still a further object of the present invention to provide a unitary switch and circuit breaker in which placing the switch in the "ON" condition resets the circuit breaker function.
It is yet object of the present invention to provide a switchable circuit breaker in which actuating the switch function avoids slow motion of the contact opening or closing action, respectively, and avoids also indefinite and incomplete contact closing conditions (so-called "non-teaseability").
The above and other objects are obtained by the present invention which provides a switchable circuit breaker comprising:
a housing;
a pair of contacts disposed within said housing;
switching means for actuating said contacts to assume a first condition in which said contacts are open and a second condition in which said contacts are allowed to close; and
breaker means disposed within said housing to interrupt current flow through said contacts in response to said current flow exceeding a predetermined level and in response to actuation of said switching means to open said contacts;
said switching means including a pusher member, having a front active end and a rear drive end, that is arranged in said housing so as to be movable between an advanced position in which said active end acts on said contact to assume said first condition and a retracted position in which said pusher releases the contacts to assume said second condition;
said pusher member being guided within said housing so as to convert a linear motion of its drive end into a step-like motion of its active end in order to provide a snapping transition between said closing and opening conditions and vice versa of the contacts.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, reference is made to the following description of an exemplary embodiment thereof, and to the accompanying drawings, wherein:
FIG. 1 is an exploded, perspective view illustrating the component parts of a switchable circuit breaker in accordance with the present invention;
FIG. 2 is a side of view of the switchable circuit breaker of FIG. 1, showing the assembled parts in the open housing, the switchable circuit breaker being in "ON" position;
FIG. 3 is a side view as in FIG. 2, showing the switchable circuit breaker in "TRIPPED" position;
FIG. 4 is a side view as in FIG. 2, showing an intermediate position from "ON" to OFF" position;
FIG. 5 is a side view as in FIG. 2, showing the switchable circuit breaker in OFF" position;
FIG. 6 is a side view as in FIG. 2, showing a first intermediate position from OFF to "ON" position;
FIG. 7 is a side view as in FIG. 2, showing a second intermediate position from OFF to ON position.
DETAILED DESCRIPTION
Referring to the drawings, and initially to FIGS. 1 and 2, the preferred embodiment of a switchable circuit breaker includes an elongated housing comprising a trough-like case 1 and a cover 2 which is to be mounted on the open side of the case 1. The case 1 and the cover 2 are molded from an electrically-insulated plastic material. The case 1 defines an elongate contact chamber 11 and a separate driving chamber 12 separated from each other by a separating wall 13. The contact chamber 11 is adapted to receive a stationary contact 3 carried by a stationary contact terminal 31 and a moveable contact 4 carried by a bimetal blade spring 42 and a movable contact terminal 41. The terminals 31 and 41 are mounted in slots 15 and 16 of the case 1, so as to place the contacts 3 and 4 opposite to each other.
A pusher 5 and a slide 6, both made from insulating material, are disposed in the case 1 and guided with central or intermediate portions 51 and 61, respectively, in a guiding gap 14 of the separating wall 13. The guiding gap 14 is the only passage between the contact chamber 11 and the driving chamber 12. The intermediate portions 51 and 61 of the pusher 5 and the slide 6 are small in thickness and reduced in width, so they can be guided in a common plane side by side in the guiding gap 14 and the guiding gap can be narrow so as to provide sufficient insulation between the contact chamber 11 and the driving chamber 12. The driving chamber has an open end side in which a rocker 7 is pivotally mounted between the case 1 and the cover 2, for example by means of pivot pins 71. The pusher 5 has a front active end 52 with an actuating finger 53 directed to the bimetal blade spring 42 carrying the moveable contact 4, and a cam portion 54 formed on the side opposite to the moveable contact 4. Further, the pusher 5 has a rear driving end 55 disposed in said driving chamber 12 and engaging a first rocker arm 72. Further, a retracting pin 56 is formed downward on said rear driving end 55 which is engageable with a retracting arm 73 formed at a lower portion of the rocker 7.
The slide 6 forms a non-conducting portion 62 at its front end which is to be disposed between a stationary contact 3 and a moveable contact 4 when in a contact opening condition. Further, a recess 63 is formed on the slide 6 through which the contacts 3, 4 can be closed when the slide is in an advanced position and the breaker mechanism, i.e. the bimetal spring 42, is not in a "TRIPPED" condition. As noted, the slide 6 is guided in the common guiding gap 14 with the pusher 5, which is in alignment with the first rocker arm 72. The slide 6 has a cranked portion 64 in the driving chamber 12 so as to engage with a rear end 65 a corresponding second rocker arm 74. A compression or helical spring 8 is arranged in the driving chamber 12; this spring 8 is supported on the separating wall 13 and acts against the cranked portion 64 of the slide in order to urge the slide 6 against the second rocker arm 74 and into a contact opening position.
For assembling the switchable circuit breaker, all the functioning parts can be mounted in the case 1 and then secured in their mounting position by fastening the cover 2 on the open side of the case 1. Further, a front panel or bezel 9 can be snapped over the open housing side and over the rocker 7, this bezel 9 securing case 1 and the cover 2 together by means of clamping arms 91. Further, the whole circuit breaker can be inserted into a panel opening and secured there by means of resilient snapping arms 92.
The operation of the switchable circuit breaker is next to be described.
Referring to FIG. 2, the switchable circuit breaker is illustrated to be in its "ON" position or contact closing position. The moveable contact 4 is urged by the spring force of the bimetal blade spring 42 against the stationary contact 3 through the recess 63 of the slide 6 which is now in an advanced position. The rocker 7 is also in its "ON" position so that its second arm 74 contacts the rear end 65 of the slide 6. The closed moveable contact 4 abuts a shoulder 66 of the slide 6 keeping the slide in an advanced position against the retracting force of the compression spring 8 which is exerted against a cranked portion 64 of the slide 6. The pusher 5 is in a retracted position so that its actuating finger 53 touches only slightly the bimetal spring 42 and its cam portion 54 rests at a side wall 17 and a step 18 of the case 1.
If a current flowing across the contacts 3, 4 exceeds a predetermined value, the bimetal blade spring 42 will flex and snap, causing the moveable contact 4 to travel downwardly (in FIG. 2) and, thereby be displaced out of the plane of the slide 6 and out of the recess 63. With the moveable contact 4 disengaged from abutting with the shoulder 66, the spring 8, being biased against the cranked portion 64 of the slide 6, urges the rear end 65 of the slide and pushes the slide to move to the right in FIG. 2 and interpose with its non-conducting portion 62 between the contacts 3, 4. As a result of the slight movement, the rocker arm 74 is urged in an outward direction causing the rocker 7 to rotate in counter clockwise direction which causes the first rocker arm 72 to shift the pusher 5 in the left direction. The front end 52 then sits between the bimetal spring 42 and the step 18 of the casing. The rocker will be positioned in an intermediate "ON" and "OFF" position, indicating a "TRIPPED" condition as illustrated in FIG. 3.
Now a switching operation from "ON" position (FIG. 2) to "OFF" position (FIG. 5) is to be described.
As a force F is applied manually to turn the circuit breaker to the "OFF" position, the rocker 7 rotates in a counter clockwise direction and pushes the pusher 5 to the left. The pusher has at its cam portion 54 a ramp 57 which has to be moved over the step 18 on the case 1 causing the pusher to have a downward motion in FIG. 4. This motion will cause the actuating finger 53 of the pusher 5 to separate the moveable contact 4 from the stationary contact 3 by exerting a downward force on the bimetal spring 42. Due to the step 18, the separation of contacts will occur in a step-like or snapping manner, avoiding thus slow motion in the contact opening operation. The separation of contacts will allow the non-conducting portion 62 of the slide 6 to interpose between the contacts by the spring force of the compression spring 8. The pusher 5 holds off the bimetal spring 42 not allowing the moveable contact 4 to move to its closed position or touch the slide surface (FIG. 5). In order to reduce so-called "tease-ability" from "ON" to "OFF" position, the breaker is designed such that the contacts will not start to separate until the pusher ramp 57 reaches the step 18 and starts moving down the step. This will allow the bimetal spring force and its direction relative to the pusher ramp 57 to push the pusher 5 back to its "ON" position (closed contacts), if the operator should release the rocker 7 before the slide 6 has interposed between the contacts (FIG. 3). In order to apply the above principle during the entire pass from "ON" to "OFF" position, the slide 6 with its non-conducting portion 62 should interpose between the contacts 3, 4 before the pusher 5 clears the step 18.
Now a switching operation from "OFF" to "ON" position is to be described.
As illustrated in FIG. 6, a manual force F is applied to turn the circuit breaker from its "OFF" position (or "TRIPPED" position according to FIG. 3) to the "ON" position (FIG. 6). The rocker 7 and its projecting retracting arm 73 move in a clockwise direction. As can clearly be seen from FIG. 5, there is a considerable clearance between the projecting arm 73 and the retracting pin 56 of the pusher 5 when the rocker is in the "OFF" position. Thus, the projecting arm 73 will engage the retracting pin 56 not earlier than the rocker has rotated a predetermined angle as shown in FIG. 6. Before the projecting arm 73 reaches the retracting pin 56 of the pusher 5, the only significant forces are the manual force F and the spring forces. Therefore, if the manual force F is removed at anytime during this period, the rocker 7 will return to its "OFF" position FIG. 5). As the rocker 7 moves in the clockwise direction, it will also push the slide 6 to the left allowing its recess 63 to align with the contacts 3, 4. When the projecting arm 73 touches and pulls back the pusher FIG. 7), the moveable contact 4 will drop through the recess 63 in the slide 6 and touch the stationary contact 3. This eliminates tease-ability from "OFF to "ON" position.
It is to be noted, that the position of the rocker 7 indicates with its angle position the condition of the switching and the circuit breaker mechanism, the end position as in FIG. 2 shows the switched "OFF" condition, the end position of the rocker 7 in counter clockwise direction as in FIG. 5 shows the switched "OFF" condition while an intermediate position of the rocker 7 as in FIG. 3 shows the TRIPPED condition of the circuit breaker.
While there has been described herein what is considered to be the preferred embodiment of the invention, other modifications may occur by those skilled in the art, and it is intended that the appended claims are to cover by such modifications which fall within the true spirit and scope of the invention.
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A switchable circuit breaker having a housing, stationary and moveable contacts, a switching member for actuating the contacts to assume a first condition in which the contacts are open and a second condition in which the contacts are closed, and a breaker is disposed within the housing to interrupt current flow through the contacts in response to the current flow exceeding a predetermined level. The switching member includes a pusher moveable between an advanced position in which the pusher acts on the contacts to assume a contact opening condition and a retracted position in which the pusher releases the contacts to assume a contact closing position. The pusher is guided within the housing so as to convert a linear motion of its drive end into a steplike motion of its active end in order to provide a snapping transition between the closing and opening conditions of the contacts, thus assuring "non-teaseability" in the switching operation.
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PRIORITY CLAIM
[0001] The present application is a continuing application of U.S. application Ser. No. 14/187,568, filed on Feb. 24, 2014 by Erick B. Iezzi, entitled “SINGLE-COMPONENT MOISTURE-CURABLE COATINGS BASED ON N-SUBSTITUTED UREA POLYMERS WITH EXTENDED CHAINS AND TERMINAL ALKOXYSILANES,” which claimed the benefit of U.S. Provisional Application No. 61/781,719, filed on Mar. 14, 2013 by Erick B. Iezzi, entitled “IMPROVED FLEXIBILITY, GLOSS RETENTION AND ADHESION OF SINGLE-COMPONENT TOPSIDE COATINGS BASED ON N-SUBSTITUTED UREAS WITH TERMINAL ALKOXYSILANES AND SECONDARY DIAMINE LINKAGES,” the entire contents of each are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to moisture-curable single-component (1K) topcoat coatings.
[0004] 2. Description of the Prior Art
[0005] The U.S. Navy's predominant topside coatings are haze gray semi-gloss silicone alkyds. These coatings have been used on the topsides (freeboard and superstructure) of surface ships by the Navy since the early 1960s. Silicone alkyd coatings are considered “user friendly” in that they are single-component (all-in-one can) paints that have an indefinite pot-life in a closed can, have been reformulated to maintain compliance with volatile organic compound (VOC) limits, and will cure even under the most adverse conditions. Unfortunately, these user-friendly paints have several inherent limitations, which include color fading, chalking, loss of gloss, limited resistance to shipboard hydrocarbons, and limited surface hardness that makes running rust and soot staining extremely difficult to remove. In addition, peeling, cracking and delamination of cured silicone alkyds can often result due to application over inadequately prepared surfaces.
[0006] Silicone alkyd coatings can be formulated as single-component (1K) systems because they contain unsaturated fatty acid groups that crosslink in the presence of atmospheric oxygen. The coatings do not begin to cure until they are applied to a surface and the solvent evaporates, thereby possessing essentially a limitless pot-life in a closed can. For Navy ships, silicone alkyd topside coatings are specified as a Haze Gray color with a semi-gloss finish, are available in a variety of volatile organic compound (VOC) levels (e.g., 340 g/L, 250 g/L), and have a service-life of approximately 6-12 months. Frequently, silicone alkyd coatings need to be touched-up or repaired (e.g., via roller or brush), yet this mundane task would not be required if silicone alkyd coatings did not easily fade, discolor, peel/delaminate or stain within a few months after application. A single application of silicone alkyd is specified at 2-5 mils dry film thickness (DFT); however, due to the constant over-coating for maintenance, it is not uncommon for surfaces to possess greater than 50 mils of topside coating.
[0007] Although Navy surface ships utilize silicone alkyd topcoats, the majority of topcoats used by the Navy are polyurethanes. Polyurethanes are formed by reaction of an isocyanate-functional material with a hydroxyl-functional material (e.g., polyester polyol or water), and are used to provide protective camouflage, exterior color stability, flexibility, chemical warfare agent resistance, hydrocarbon resistance and chemical resistance. Polyurethane topcoats can be two-component systems or single-component systems. Polyurethane topcoats contain toxic isocyanates that can cause serious health issues for both coating applicators and the environment, and non-isocyanate alternatives that offer equal or greater performance are of high interest. Furthermore, two-component coatings require the mixing of components before application, which can result in insufficient cure times, reduced hardness, poor adhesion, and poor appearance if applicators do not mix the materials correctly. Two-component coatings also have a limited pot-life, which is an issue for individuals performing touch-up and repair applications. For these reasons, single-component coatings are favored over two-component systems.
[0008] Polysiloxane-based coatings have an inherent durability advantage over traditional organic-based materials due to the presence of silicon-oxygen bonds. The Si—O bond, which has a bond enthalpy of 110 kcal/mol, is stronger than the carbon-hydrogen (99 kcal/mol) and carbon-carbon (83 kcal; mol) bonds found in organic coatings, thereby leading to an increase in thermal stability and resistance to oxidative degradation by sunlight. Polysiloxanes, like many silicon-based materials, are relatively non-toxic to humans, especially when compared to the health issues associated with isocyanate-containing materials.
[0009] Two-component (2K) polysiloxane coatings are based on materials that contain both reactive organic groups and moisture-curable alkoxysilane groups. These coatings are often referred to as “hybrid cure coatings,” where one portion of the coating is crosslinked by the ambient reaction between organic groups, such as amines and epoxies, while the other portion forms a siloxane network via moisture hydrolysis of the alkoxysilane groups and condensation of the resulting silanols. These coatings offer good exterior durability, hardness, chemical resistance, and direct-to-metal adhesion. However, they can suffer from photooxidation and yellowing due to the presence of amines, which affects the long-term color and gloss stability of these coatings. Similar to two-component polyurethanes, these materials suffer from poor application appearance and performance if not mixed correctly by applicators, not to mention the limited pot-life and waste associated with a two-component system.
[0010] Single-component polysiloxane coatings are traditionally based on acrylic-silane polymers. These polymers are manufactured via radical polymerization of gamma-methacryloxypropyltrimethoxysilane with methyl methacrylate, hexyl acrylate or other organic monomers to form linear copolymers with pendant alkoxysilane groups. The copolymers are high in molecular weight and require significant quantities of solvent(s) to solubilize the large polymer chains, thus making it difficult to generate low VOC coatings. The pendant alkoxysilane groups are the only reactive functionalities on the copolymer, which enables the coating to be cured via moisture hydrolysis and condensation. Single-component coatings based on these polymers are available on the commercial market from several manufacturers, although they are not without their drawbacks. For instance, these coatings are slow to hydrolyze and crosslink (cure) at room temperature when not exposed to high humidity environments, and they display poor chemical resistance when not fully cured due to the low crosslink density within the coating. These issues result because the acrylic-silane copolymers in the coating contain pendent propyltrialkoxysilane groups that are inherently slow to hydrolyze and limited in quantity when compared to the non-reactive groups in the copolymer backbone. Acrylic-silane binders often possess glass transition temperatures (Tgs) above room temperature in order to provide fast dry-to-touch times (e.g., 1-3 hours), even though the crosslinking reaction between polymers is slow to occur.
[0011] Single-component moisture-curable coating compositions were disclosed in U.S. Pat. No. 6,288,198. These coatings are based on aliphatic polyisocyanate-aminosilane adducts, where greater than 70% of the isocyanate groups are reacted with an aminosilane, which is then combined with a hydrolysable silane to form a hybrid sol-gel coating. It is stated that these sol-gel coatings provide hard, abrasion-resistant and solvent-resistant surfaces, which is expected for highly-crosslinked coatings, especially those that contain small hydrolyzable silanes. However, the reported flexibility is only a 90 degree bend, not a 180 degree bend, which is the norm when referring to a highly flexible coating. Furthermore, the preferred coating dry film thickness is only 2-30 microns, which is significantly less than what is utilized for most commercial and military coatings. An additional drawback to these coating compositions are that the high content of moisture-curable silane groups within the coatings leads to a continual reduction in gloss over time as the coating post-cures with moisture.
[0012] Single-component moisture-curable coatings were also disclosed in U.S. Pat. No. 8,133,964, and are based on similar aliphatic polyisocyanate-aminosilane adducts as those discussed above (paragraph [0009]). However, these adducts are formed by reacting polyisocyanates with 2:1 or 1:2 ratios of N-substituted aminosilanes and di-substituted mono-functional amines. Reactive diluents, such as hydrolyzable silanes or polysiloxanes could also be utilized. The di-substituted mono-functional amines reduced the amount of hydrolysable silane groups on the polyisocyanate-aminosilane adduct, but the overall high concentration of moisture-curable silane groups in the coating yielded topcoats with only slightly better flexibility than coatings reported in U.S. Pat. No. 6,288,198. The coatings still provided good solvent resistance, high hardness and low VOCs. Additional drawbacks of these coatings are that the high content of moisture-curable groups leads to a continual reduction in gloss over time as the coatings post-cure with moisture, and that the use of the di-substituted mono-functional amines results in slow tack-free and dry-through times for the coatings.
BRIEF SUMMARY OF THE INVENTION
[0013] The present invention relates to moisture-curable single-component coatings that are highly flexible, are gloss retentive, provide fast tack-free and dry-through times, provide good adhesion, are highly resistant to solvents, and offer excellent exterior color stability to sunlight. The solution is provided by synthesizing N-substituted urea polymers with extended chains and terminal alkoxysilane groups, then formulating into moisture-curable single-component coatings. The coating formulations can also comprise reactive diluents, pigments, fillers, solvents, additives and a catalyst. These single-component coatings can be applied over a substrate via spray, brush or roll application methods.
[0014] The single-component coatings of the present invention provide greater exterior stability, adhesion, solvent resistance, flexibility and lower VOC content than the silicone alkyd topside coatings currently utilized on Navy ships. These coatings are also isocyanate-free, in that the N-substituted urea polymers with extended chains and terminal alkoxysilanes, including the reactive diluents and additives, contain no unreacted isocyanate groups. These coatings can be formulated to provide high-gloss, semi-gloss and low-gloss finish coatings, and thus have application as coatings for use on commercial and military assets (e.g., ships, aircraft, ground vehicles and submarines).
[0015] The high flexibility of the herein coatings result from N-substituted urea polymers with extended chains and terminal alkoxysilanes that are synthesized utilizing aliphatic or cycloaliphatic secondary diamine chain extenders, and also by limiting the amount of reactive alkoxsilane groups on the polymers. The N-substituted urea linkages formed during reaction of these chain extenders with isocyanates provides for greater flexibility than if forming non-N-substituted ureas. The N-substituted group on the urea causes steric interactions within the linkage, and these interactions are minimized by the N-substituted group rotating slightly out of plane. N-substituted urea linkages, as opposed to non-N-substituted, also provide for polymers with reduced viscosity due to less inter- and intra-molecular hydrogen bonding between ureas. This in turn allows for polymers with reduced solvent content, and hence higher solids content, to be synthesized. The use of N-substituted urea polymers also allow for single-component coatings with lower volatile organic compounds (VOCs) to be formulated. All newly formed urea linkages within the polymers are N-substituted, including those located near the terminal alkoxysilane groups.
[0016] The fast tack-free times for the herein single-component coatings are achieved by using N-substituted urea polymers with extended chains and terminal alkoxysilanes that possess glass transition temperatures near or above room temperature. These glass transition temperatures result from addition of the secondary diamine chain extenders during polymer synthesis, which forms larger molecules, such as dimers and trimers, and thus increases the overall molecular weight of the polymer. The fast dry-through times for the coatings are due to the fast curing nature of the terminal alkoxysilane groups on the polymers. The terminal alkoxysilane groups are located near N-substituted urea linkages, and will react more rapidly with moisture than if non-N-substituted linkages were used, such as in the case of acrylic-silane polymers.
[0017] The gloss retention of the herein single-component coatings are improved by reducing the amount of moisture-curable alkoxysilane groups within the coating. Alkoxysilane groups within moisture-curable coatings are known to post-cure slowly for weeks, and even months, after the coatings have cured, and this is especially true in high humidity environments. As post-curing occurs over time, the gloss level of a moisture-curable coating can decrease, and may no longer provide the same appearance. This is especially important for military-specified coatings, such as the semi-gloss topside coatings used on Navy surface ships. Thus, by limiting the amount of terminal alkoxysilane groups on the N-substituted urea polymers, single-component coatings can be formulated where post-curing is minimized.
[0018] Adhesion of the single-component coatings of the present invention to epoxy primers can be improved by utilizing various N-substituted groups, such as ester-containing aliphatics, that provide hydrogen bonding with the underlying substrate.
[0019] In one embodiment of the present invention, a moisture-curable single-component coating comprises an N-substituted urea polymer with extended chains and terminal alkoxysilane groups, a catalyst and a solvent.
[0020] In a second embodiment, a moisture-curable single-component coating comprises an N-substituted urea polymer with extended chains and terminal alkoxysilane groups, a reactive diluent, a catalyst, a pigment, a filler, an additive, and a solvent.
[0021] In another embodiment, the N-substituted urea polymer with extended chains and terminal alkoxysilane groups comprises an aliphatic polyisocyanate, N-substituted amino-functional alkoxysilanes, and a secondary diamine chain extender.
[0022] In yet another embodiment, a method for producing a single-component coating composition comprises synthesizing an N-substituted urea polymer with extended chains and terminal alkoxysilane groups by first reacting an aliphatic polyisocyanate with an N-substituted amino-functional alkoxysilane, followed by reaction with a secondary diamine chain extender, such that no unreacted isocyanate remains, then mixing the synthesized polymer with a reactive diluent, a pigment, a filler, a solvent, a catalyst, an additive, or a combination thereof.
[0023] It is understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. These and other features and advantages of the invention, as well as the invention itself, will become better understood by reference to the following detailed description, appended claims, and accompanying drawings, or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a structure of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using an aliphatic polyisocyanate based on an HDI isocyanurate trimer, N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine (a cycloaliphatic secondary diamine chain extender).
[0025] FIG. 2 is a structure of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using an aliphatic polyisocyanate based on an HDI isocyanurate trimer, a Michael Addition adduct of butyl acrylate and 3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and N 1 ,N 3 -diethylpropane-1,3-diamine (an aliphatic secondary diamine chain extender).
[0026] FIG. 3 is a structure of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using a 1:1 mixture of an aliphatic polyisocyanate based on an HDI isocyanurate trimer and an aliphatic polyisocyanate based on a uretdione, N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and N 1 ,N 6 -dimethylhexane-1,6-diamine (an aliphatic secondary diamine chain extender).
[0027] FIG. 4 is a structure of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using an aliphatic polyisocyanate based on a uretdione, N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and a 1:1 mixture of N 1 ,N 6 -dimethylhexane-1,6-diamine (an aliphatic secondary diamine chain extender) and N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine (a cycloaliphatic secondary diamine chain extender).
DETAILED DESCRIPTION OF THE INVENTION
[0028] References will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying figures.
[0029] A single-component coating means that all components are pre-mixed and does not require the addition of additives, a catalyst or reactive components before being applied to a substrate. The coating may need to be shaken or stirred before use, but the entire product is contained within a single can or container. A single-component coating is considered “user friendly” because it can be easily applied to a substrate, then restored simply by closing the container. Single-component coatings generate less waste than two-component coatings, because only the material removed from the can is utilized, unlike two-component coatings where the mixed materials will solidify and become waste if not utilized. The term “single-component” coating is often referred to as “1K”, which is an abbreviation for 1 Komponent (the German spelling of component). However, “1K” is not intended to mean that the coating is made from a single chemical or substance, but rather that the end product does not need to be mixed with another component before application to a substrate.
[0030] An exemplary single-component coating composition of the present invention comprises an N-substituted urea polymer with extended chains and terminal alkoxysilanes, where the polymer is formed from an aliphatic polyisocyanate, N-substituted amino-functional alkoxysilanes, and a secondary diamine chain extender, such that no free isocyanate groups remain. The polymer has an N-substituted group at all urea linkages that are formed during the reaction process. The alkoxysilane groups are located at the terminus of the polymer, and the chain extenders are located internally. The single-component coating composition can also comprise a reactive diluent, a solvent, a catalyst, a pigment, a filler, an additive, or a mixture thereof.
[0031] The N-substituted urea polymer with extended chains and terminal alkoxysilanes is the reaction product of an aliphatic polyisocyanate, N-substituted amino-functional alkoxysilanes, and a secondary diamine chain extender. The aliphatic isocyanate should have at least 2 isocyanate (NCO) reactive groups per molecule. The aliphatic isocyanate is first reacted with an N-substituted amino-functional alkoxysilane to generate N-substituted urea linkages and terminal alkoxysilane groups. The secondary diamine chain extender is then reacted with the remaining isocyanate groups. Reaction of the secondary diamine chain extender with the isocyanate groups generates N-substitute urea linkages, while also increasing the size of the resulting polymer and forming dimers, trimers, tetramers, etc. The polymer should contain no unreacted isocyanate groups once the reaction is finished. The polymer can be synthesized in a solvent or combination of solvents.
[0032] In an exemplary embodiment, the aforementioned polymer is formed by reacting 30-95% of the isocyanate groups on the aliphatic polyisocyanate with an N-substituted amino-functional alkoxysilane, and 5-70% of the isocyanate groups on the aliphatic polyisocyanate with a secondary diamine chain extender, such that no unreacted isocyanate remains in the polymer. Addition of the chain extender forms larger molecules (e.g, dimers, trimers), which increases the overall molecular weight of the polymer.
[0033] The aliphatic polyisocyanate can be aliphatic or cycloaliphatic. Aliphatic polyisocyanates are more weatherable (exterior durable) than aromatic polyisocyanates, thereby providing greater color stability when utilized for exterior coatings. Aliphatic polyisocyanates can have various numbers of reactive isocyanate (NCO) groups per molecule, depending on their structure. Typically, the number ranges from 2.5 to 5.5. For the present invention, the aliphatic polyisocyanate should have greater than 2 NCO groups per molecule. Suitable aliphatic polyisocyanates include, but are not limited to, structures based on isocyanurates (e.g., HDI and IPDI trimers), biurets, uretdiones, allophanates, oxadiazinetriones, iminooxadiazinedione, and prepolymers containing urethanes. Mixtures of these isocyanates can also be used. There are many commercially available aliphatic polyisocyanates.
[0034] The N-substituted amino-functional alkoxysilane can be N-substituted 3-aminopropyltrialkoxysilane, N-substituted 3-aminopropylalkyldialkoxysilane or N-substituted dialkylalkoxysilane, where the alkyl group attached to the silicon atom can be methyl or ethyl, and the alkoxy group attached to the silicon atom can be methoxy, ethoxy, n-propoxy or n-butoxy.
[0035] The N-substituted group of the amino-functional alkoxysilane can be C1-C12 alkyl or cycloalkyl. Examples include, but are not limited to, N-methyl-3-aminopropyltrimethoxysilane, N-ethyl-3-aminopropyltriethoxysilane, N-methyl-3-aminopropyltributoxysilane, N-ethyl-3-aminopropyltripropoxysilane, N-iso-propyl-3-aminopropyltrimethoxysilane, N-tert-butyl-3-aminopropyltrimethoxysilane, N-butyl-3-aminopropyltrimethoxysilane, N-butyl-3-aminopropylmethyldimethoxysilane, N-butyl-3-aminopropyldimethylmethoxysilane, N-butyl-3-aminopropyltriethoxysilane, N-butyl-3-aminopropyltripropoxysilane, N-butyl-3-aminopropyltributoxysilane, N-iso-butyl-3-aminopropyltrimethoxysilane, N-cyclohexyl-3-aminopropyltrimethoxysilane, N-hexyl-3-aminopropyltrimethoxysilane, N-nonyl-3-aminopropytrimethoxysilane and N-dodecyl-3-aminopropyltrimethoxysilane. Many of these are commercially available.
[0036] The N-substituted group of the amino-functional alkoxysilane can also be an ester-containing aliphatic or ester-containing fluorinated aliphatic, which are formed by the Michael Addition (conjugate addition) reaction between a molecule with a reactive “ene” group, such as an acrylate, and 3-aminopropyltrialkoxysilane, 3-aminopropylalkyldialkoxysilane or 3-aminopropyldialkylalkoxysilane. Conditions for forming Michael Addition adducts with an amine are well known in the literature. Suitable acrylates include, but are not limited to, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, 4-tert-butylcyclohexyl acrylate, diethyl maleate, dimethyl maleate, dibutyl maleate, ethylene glycol methyl ether acrylate, 1,1,1,3,3,3-hexafluoroisopropyl acrylate, 2,2,2-trifluoroethyl acrylate and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate. Examples include, but are not limited to, methyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate, butyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate, 2-ethylhexyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate, octyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate, 3,3,3-trifluoropropyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate, dimethyl (3-(trimethoxysilyl)propyl)aspartate and diethyl (3-(trimethoxysilyl)propyl)aspartate.
[0037] The N-substituted group of the amino-functional alkoxysilane can also be an amide-containing aliphatic, which is formed by the Michael Addition (conjugate addition) reaction between a molecule with a reactive “ene” group, such as an acrylamide, and 3-aminopropyltrialkoxysilane, 3-aminopropylalkyldialkoxysilane or 3-aminopropyldialkylalkoxysilane. Suitable acrylamides include, but are not limited to, N-ethylacrylamide, N-propylacrylamide, N-tert-butylacrylamide, N-cyclohexylacrylamide, N-ethyl maleimide and N,N′-diethylmaleamide. Examples include, but are not limited to, N-propyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide, N-butyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide, N-cyclohexyl-3-((3-(trimethoxysilyl)propyl)amino)propanamide and 1-ethyl-3-((3-(trimethoxysilyl)propyl)amino)pyrrolidine-2,5-dione.
[0038] The secondary diamine chain extender is a molecule that contains two reactive secondary amine groups, or N-substituted groups, with a chain of atoms between. These secondary diamine chain extenders are used for reacting with the isocyanate groups, extending the chain length between the terminal alkoxysilanes, and increasing the overall molecular weight of the N-substituted urea polymer. The secondary diamines form N-substituted urea linkages once reacted with the isocyanate groups. The secondary diamine chain extenders provide increased flexibility, exterior durability, and faster tack-free times for the N-substituted urea polymer and subsequent single-component coating. A mixture of secondary diamine chain extenders can be used to provide tailored flexibility and hardness. The secondary diamine chain extender can be an aliphatic or cycloaliphatic chain with secondary diamines, such as a bis(secondary diamine). The secondary diamine chain extender can also be, but is not limited to, a dimethylpolysiloxane chain with secondary diamines, a methylphenylpolysiloxane chain with secondary diamines, a polyether chain with secondary diamines, a polysulfide chain with secondary diamines, or a mixture thereof.
[0039] The N-substituted groups of the secondary diamines can be C1-C12 alkyl, cycloalkyl or ester-containing aliphatic. The N-substituted groups can be produced by reacting an amine with an aldehyde or ketone (e.g., acetone, methylethylketone) then reducing (hydrogenating). The N-substituted groups can also be produced by reacting an amine with a molecule containing a reactive “ene” group, such as an acrylate or maleate, via a Michael Addition (conjugate addition) reaction. Suitable secondary diamine chain extenders include, but are not limited to, the following:
[0000]
Structure
Name
N 1 ,N 3 -dimethylpropane-1,3-diamine
N 1 ,N 3 -diethylpropane-1,3-diamine
N 1 ,N 5 -diisopropyl-2-methylpentane-1,5- diamine
N 1 ,N 6 -dimethylhexane-1,6-diamine
N 1 ,N 6 -bis(3,3-dimethylbutan-2-yl)hexane-1,6- diamine
N,3,3,5-tetramethyl-5- ((methylamino)methyl)cyclohexan-1-amine
N-isopropyl-3-((isopropylamino)methyl)- 3,5,5-trimethylcyclohexan-1-amine
tetraethyl 2,2′-((2-methylpentane-1,5- diyl)bis(azanediyl))disuccinate
4,4′-methylenebis(N-isopropylcyclohexan-1- amine)
tetraethyl 2,2′-((methylenebis(cyclohexane- 4,1-diyl))bis(azanediyl))disuccinate
4,4′-methylenebis(N-(sec-butyl)cyclohexan-1- amine)
dibutyl 3,3′-(hexane-1,6- diylbis(azanediyl))dipropionate
3,3′-(1,1,3,3-tetramethyldisiloxane-1,3- diyl)bis(N-methylpropan-1-amine)
N,N′-isopropylaminopropyl terminated polydimethylsiloxane
N,N′-ethylaminoisobutyl terminated polydimethylsiloxane
[0040] Several secondary diamine chain extenders are commercially available.
[0041] A person skilled in the art understands that secondary triamines, secondary tetramines, secondary pentaamines, or larger, could also be utilized as the chain extender, although the viscosity of the resulting N-substituted urea polymer would be greater than if using a similar secondary diamine.
[0042] The N-substituted urea polymer with extended chains and terminal alkoxysilanes is the reaction product of an aliphatic polyisocyanate, an N-substituted amino-functional alkoxysilane, and a secondary diamine chain extender. As discussed above, numerous aliphatic polyisocyanates, secondary diamine chain extenders and N-substituted amino-functional alkoxysilanes can be utilized, thus providing the ability to generate a large variety of polymers that possess differences in molecular weight, structure and properties (e.g., cure times, hardness, flexibility, solvent resistance and exterior weathering resistance). In an example synthesis of the N-substituted urea polymer with extended chains and terminal alkoxysilanes, the polymer is the reaction product of (i) an aliphatic polyisocyanate with at least 2 isocyanate (NCO) reactive groups per molecule, where (ii) 30-95% of the isocyanate groups are reacted with an N-substituted amino-functional alkoxysilane, and (iii) 5-70% of the isocyanate groups are reacted with a secondary diamine chain extender, such that no unreacted isocycanate remains in said polymer. Preferably, the N-substituted urea polymer with extended chains and terminal alkoxysilanes is the reaction product of (i) an aliphatic polyisocyanate with at least 2 isocyanate (NCO) reactive groups per molecule, where (ii) 50-80% of the isocyanate groups are reacted with an N-substituted amino-functional alkoxysilane, and (iii) 20-50% of the isocyanate groups are reacted with a secondary diamine chain extender, such that no unreacted isocycanate remains in said polymer. More preferably, the N-substituted urea polymer with extended chains and terminal alkoxysilanes is the reaction product of (i) an aliphatic polyisocyanate with at least 2 isocyanate (NCO) reactive groups per molecule, where (ii) 60-70% of the isocyanate groups are reacted with an N-substituted amino-functional alkoxysilane, and (iii) 30-40% of the isocyanate groups are reacted with a secondary diamine chain extender, such that no unreacted isocycanate remains in said polymer.
[0043] A person skilled in the art understands that a small amount of isocyanate groups (e.g., 1-5%) could remain unreacted in the polymer, and thereby could be used to assist with adhesion to a substrate, or could be used to react with an isocyanate-reactive material that is not discussed in this invention. However, reacting a small percentage of the isocyanate groups on a polymer with a non-disclosed material is not expected to change the properties of the polymer, and should not be considered a separate invention. For the purpose of making isocyanate-free coatings, it is recommended that all isocyanate groups be reacted during synthesis of the N-substituted urea polymer.
[0044] The structure in FIG. 1 is an example of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using an aliphatic polyisocyanate based on an HDI isocyanurate trimer, N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine (a cycloaliphatic secondary diamine chain extender). In this example, all newly formed N-substituted urea groups possess either a butyl or isopropyl group.
[0045] Alternative structures of N-substituted urea polymers with extended chains and terminal alkoxysilanes can be formed by varying the type of aliphatic polyisocyanate, N-substituted amino-functional alkoxysilane, or the secondary diamine chain extender utilized in the synthetic process.
[0046] The structure in FIG. 2 is an example of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using an aliphatic polyisocyanate based on an HDI isocyanurate trimer, a Michael Addition adduct of butyl acrylate and 3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and N 1 ,N 3 -diethylpropane-1,3-diamine (an aliphatic secondary diamine chain extender). This polymer demonstrated improved adhesion to certain epoxy primers due to the increased hydrogen bonding that the butyl-ester groups provide.
[0047] Alternative structures of N-substituted urea polymers with extended chains and terminal alkoxysilanes can be formed by utilizing a mixture of two different aliphatic isocyanates, an N-substituted amino-functional alkoxysilane, and a secondary diamine chain extender.
[0048] The structure in FIG. 3 is an example of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using a 1:1 mixture of an aliphatic polyisocyanate based on an HDI isocyanurate trimer and an aliphatic polyisocyanate based on a uretdione, N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and N 1 ,N 6 -dimethylhexane-1,6-diamine (an aliphatic secondary diamine chain extender). The N-substituted amino-functional alkoxysilane is reacted with ˜60% of the isocyanate groups, whereas the secondary diamine chain extender is reacted with ˜40% of the isocyanate groups. The structure is asymmetric due to the use of two different aliphatic polyisocyanates.
[0049] The structure in FIG. 4 is an example of an N-substituted urea polymer with extended chains and terminal alkoxysilanes that is synthesized using an aliphatic polyisocyanate based on a uretdione, N-butyl-3-aminopropyltrimethoxysilane (an N-substituted amino-functional alkoxysilane), and a 1:1 mixture of N 1 ,N 6 -dimethylhexane-1,6-diamine (an aliphatic secondary diamine chain extender) and N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexan-1-amine (a cycloaliphatic secondary diamine chain extender). The N-substituted amino-functional alkoxysilane is reacted with ˜50% of the isocyanate groups, whereas the secondary diamine chain extenders are reacted with ˜50% of the isocyanate groups. The structure is asymmetric due to the use of two different secondary diamine chain extenders. The reason for the use of two different chain extenders is to provide tailored properties of both hardness and flexibility.
[0050] Properties of the synthesized polymers were evaluated by applying the polymer solutions to tinplate panels or Laneta cards at 2 to 6 mils (50.8 to 152.4 microns) wet film thickness. The resulting dry film thickness of each film (a clear coating) depended on the percentage volume solids of the polymer solution. In general, and without using a catalyst, the N-substituted urea polymers with extended chains and terminal alkoxysilanes have tack-free times of only a few hours. This is due to the polymers having glass transition temperatures near or above room temperature. After 7 days of curing at ambient conditions, the clear coatings demonstrate a resistance of 50-100 double rubs to methyl ethyl ketone (MEK) solvent. Furthermore, when tested for flexibility, the clear coatings pass a 180 degree bend test and a ¼″ Mandrel Bend test without cracking. The coatings could also be straightened and bent numerous times without damage. Addition of only 1 weight % of a catalyst, based on polymer solids, provided clear coatings with dry-through times of 3-6 hours and a solvent resistance of >100 MEK double rubs. The flexibility was unaffected by addition of a catalyst.
[0051] The N-substituted urea polymers with extended chains and terminal alkoxysilanes are used to formulate both clear and pigmented single-component coatings. The single-component coatings can also comprise a reactive diluent, a filler, a pigment, a solvent, an additive, a catalyst, or a mixture thereof.
[0052] A reactive diluent may be used for modifying the properties of the single-component coating, such as increasing the flexibility or hardness, reducing solvent content and viscosity, or increasing resistance to exterior degradation from sunlight. The reactive diluent can be a polysiloxane with at least 2 hydrolyzable alkoxysilane groups, such as, but not limited to, poly(dimethoxysiloxane), poly(diethoxysiloxane), methoxy-functional dimethylpolysiloxane, methoxy-functional methylphenylpolysiloxane, ethoxy-functional dimethylpolysiloxane, and structures based on tetraethyl orthosilicate. The reactive diluent can also be hydroxyl-functional versions (via hydrolysis) of these polysiloxanes. Many of these are commercially available.
[0053] The reactive diluent can also be an alkyl-functional alkoxysilane, where the alkyl group is C1-C16 alkyl, cycloalkyl or fluorinated alkyl, and the alkoxysilane group is trimethoxysilane, triethoxysilane, methyldimethoxysilane, methyldiethoxysilane, dimethylmethoxysilane and dimethylethoxysilane. Examples include, but are not limited to, propyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, hexadecyltrimethoxysilane, cyclohexyltriethoxysilane and 1H,1H,2H,2H-perfluorooctyltriethoxysilane.
[0054] The reactive diluent can also be a polysiloxane-urea polymer with hydrolysable alkoxysilane groups. These reactive diluents are formed by reacting a polysiloxane with primary diamines or a polysiloxane with secondary diamines with 3-isocyanatopropyltrimethoxysilane or 3-isocyanatotriethoxysilane. They can also be formed by reacting a diisocyanate-functional polysiloxane with an N-substituted 3-aminopropylalkoxysilane. The polysiloxane can be a dimethylpolysiloxane or methylphenylpolysiloxane. The N-substituted groups of the secondary diamines (attached to the polysiloxane) and N-substituted 3-aminopropylalkoxysilane can be C1-C12 alkyl, cycloalkyl or ester-containing aliphatic. The alkoxysilane group of the N-substituted 3-aminopropylalkoxysilane can be trimethoxysilane, triethoxysilane, methyldimethoxysilane, methyldiethoxysilane, dimethylmethoxysilane and dimethylethoxysilane. There are several commercial sources of the raw materials for synthesizing these reactive diluents. Example structures of these synthesized reactive diluents include, but are not limited to, the following:
[0000]
Structure
Name
Bis((3- triethoxysilyl)propyl)urea adduct based on N,N′- ethylaminoisobutyl terminated polydimethylsiloxane
Bis((3- triethoxysilyl)propyl)urea adduct based on aminopropyl terminated polydimethylsiloxane
Bis(N-substituted 3-aminopropylalkoxysilane) urea adduct based on diisocyanate-functional polydimethylsiloxane
[0055] Reactive diluents that contain N-substituted urea groups are used due to their reduced hydrogen bonding character, lower viscosity and reduced solvent requirements.
[0056] The reactive diluent can also be an aliphatic or cycloaliphatic N-substituted urea with hydrolysable alkoxysilane groups. These reactive diluents are formed by reacting an aliphatic or cycloaliphatic secondary diamine chain extender with 3-isocyanatopropyltrimethoxysilane or 3-isocyanatotriethoxysilane. The 3-isocyanatopropyltrimethoxysilane and 3-isocyanatotriethoxysilane are commercially available. Suitable secondary diamine chain extenders are the same as those utilized for synthesizing the N-substituted urea polymer with extended chains and terminal alkoxysilanes. Example structures of these synthesized reactive diluents include, but are not limited to, the following:
[0000]
Structure
Name
1,1′-(hexane-1,6-diyl)bis(1- (3,3-dimethylbutan-2-yl)-3- (3- (triethoxysilyl)propyl)urea)
1-isopropyl-1-((5-(1- isopropyl-3-(3- (triethoxysilyl)propyl)ureido)- 1,3,3- trimethylcyclohexyl)methyl)- 3-(3- (triethoxysilyl)propyl)urea
1,1′-(hexane-1,6-diyl)bis(1- methyl-3-(3- (triethoxysilyl)propyl)urea)
tetraethyl 2,2′-4,4,22,22- tetraethoxy-12-methyl- 9,17-dioxo-3,23-dioxa- 8,10,16,18-tetraaza-4,22- disilapentacosane-10,16- diyl)disuccinate
[0057] The reactive diluent can also be a polyester-urethane polymer with hydrolyzable alkoxysilane groups. These reactive diluents are formed by reacting an aliphatic or cycloaliphatic polyester polyol with 3-isocyanatopropyltrimethoxysilane or 3-isocyanatotriethoxysilane. The polyester polyol should be linear or slightly branched, and is utilized to provide increased flexibility for the single-component coating. Suitable polyester polyols are commercially available. The 3-isocyanatopropyltrimethoxysilane and 3-isocyanatotriethoxysilane are also commercially available.
[0058] Suitable solvents for synthesis of the N-substituted urea polymer with extended chains and terminal alkoxysilane groups are those that are not reactive with isocyanate groups. These solvents include, but are not limited to, xylenes, light aromatic naphtha, mineral spirits, butyl acetate, 1-methoxy-2-propyl acetate, tert-butyl acetate, butyl propionate, pentyl propionate, ethyl 3-ethoxypropionate, parachlorobenzotrifluoride, tetrahydrofuran, 1,4-dioxane, dimethylacetamide and N-methyl pyrrolidone. These solvents can also be utilized in single-component coating compositions.
[0059] A catalyst is used to accelerate the rate of hydrolysis of the terminal alkoxysilane groups on the N-substituted urea polymer with extended chains, and to facilitate crosslinking of the resulting silanol groups to form a cured coating. Suitable catalyst for the single-component coating composition include, but are not limited to, organic tin compounds, such as dibutyl tin dilaurate, dibutyl tin diacetate and dibutyl tin bis(2-ethylhexoate), metal alkoxides, such as titanium tetraisopropoxide, aluminum triethoxide and zirconium tetrabutoxide, alkalines, such as potassium hydroxide, organic acids, inorganic acids, tertiary amines, or mixtures thereof. A catalyst can be used in a clear or pigmented single-component coating.
[0060] Suitable pigments for the single-component coating composition include, but are not limited to, titanium dioxide, carbon black, red iron oxide, yellow iron oxide, copper phthalocyanine blue, sodium aluminum sulphosilicate, chromium oxide, cobalt chromite green spinel, chromium green-black hematite, nickel antimony titanium yellow rutile, and manganese-based pigments.
[0061] Suitable fillers for the single-component coating composition include, but are not limited to, amorphous silica, functionalized silica, talc, mica, wollastonite, calcium carbonate, glass beads, graphite, polymeric waxes, acrylic beads, polyurethane beads and ceramic microspheres.
[0062] Suitable additives for the single-component coating composition include, but are not limited to, rheology modifiers, thickening agents, adhesion promoters, reinforcing agents, wetting and dispersing agents, anti-floating agents, flame retardants, ultraviolet (UV) absorbers, hindered amine light stabilizers (HALS), and flow and leveling agents.
[0063] Depending on the level of catalyst and type of fillers, the single-component coating compositions have a pot-life of 6-12 months in a closed can and in the absence of moisture.
[0064] The single-component coating composition can be applied via spray, brush or roll application. The single-component coating can be applied at 1 to 12 mils (25.4 to 304.8 microns) wet film thickness, preferably 3 to 10 mils (76.2 to 254 microns) wet film thickness, and more preferably 4 to 6 mils (101.6 to 152.4 microns) wet film thickness. Viscosities are typically within the range of HVLP to pressure-pot sprayable, depending on the composition.
[0065] The single-component coating can be applied to a variety of substrates. Suitable substrates include, but are not limited to, epoxy primed surfaces, polyurethane primed surfaces, pretreatments, epoxy-based composites, weathered or abraded silicone alkyd coatings, weathered or abraded polysiloxane coatings, bare steel surfaces, bare aluminum surfaces, bare aluminum alloy surfaces, concrete, glass, ceramics and plastics.
EXAMPLES
[0066] The following examples describe the synthesis of N-substituted urea polymers with extended chains and terminal alkoxysilanes, in addition to single-component coating compositions that are based on the polymers. The examples are not to be considered as limiting the invention to their details.
Example 1
[0067] This example describes the preparation of a polymer based on an aliphatic polyisocyanate, N-alkyl amino-functional alkoxysilanes, and a cycloaliphatic secondary diamine chain extender with N-alkyl groups. The structure is shown in FIG. 1 .
[0068] 81.6 g (0.446 equiv.) of an aliphatic polyisocyanate based on an HDI isocyanurate trimer (commercially available as Desmodur N-3600 from Bayer Material Science) was dissolved in 115 g of Aromatic 100 (commercially available from Exxon) in a 500 ml 3-neck round bottom flask equipped with an Argon inlet and thermometer. This was followed by the addition of 5 g of vinyltrimethoxysilane (commercially available from Aldrich) as a drying agent. Using an addition funnel, 71.38 g (0.303 equiv.) of N-butyl-3-aminopropyltrimethoxysilane (commercially available as SIB 1932.2 from Gelest) was added dropwise to the solution while keeping the temperature at 40-50° C. Next, 18.78 g (0.147 equiv.) of N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexanamine was added dropwise while continuing to keep the temperature at 40-50° C. After the addition was complete, the solution was stirred for an additional 15-30 minutes until the infrared (IR) spectra indicated that no more free isocyanate (NCO) (2270 cm −1 ) remained in solution. The polymer solution was calculated to have a solids content of 60.6% by weight.
Example 2
[0069] A semi-gloss single-component coating composition was prepared by mixing 165.01 g of the polymer solution (100 g solid polymer by weight) in Example 1 with 11.65 g titanium dioxide, 2.9 g Shepherd Black 30C940, 1.95 g Shepherd Green 410, 1.0 g Shepherd Yellow 30C119, 20 g ceramic microspheres, 10 g Oxsol 100 and 0.5 g dibutyl tin dilaurate.
[0070] The coating was applied at 3 mils (76.2 microns) wet film thickness to tinplate panels and a laneta card, and was allowed to cure (crosslink) at ambient conditions (77° F. and 50% relative humidity). The coating demonstrated a tack-free time of 1 hour and a dry-hard time of 6 hours. After 14 days of curing at ambient conditions, the coating demonstrated a 60° gloss of 57 GU, a resistance of 100+ double rubs to methyl ethyl ketone (MEK) solvent, and a pendulum hardness of 84 oscillations. The coating also demonstrated high flexibility, and passed a 180 degree bend test and a ¼″ Mandrel Bend test without cracking.
Example 3
[0071] A semi-gloss single-component coating composition was prepared by mixing 132.01 g of the polymer solution (80 g solid polymer by weight) in Example 1 with 11.65 g titanium dioxide, 2.9 g Shepherd Black 30C940, 1.95 g Shepherd Green 410, 1.0 g Shepherd Yellow 30C119, 30 g ceramic microspheres, 20 g of a methoxy-functional dimethylpolysiloxane (commercially available as Silres SY231 from Wacker Chemical), 15 g Oxsol 100 and 1.0 g dibutyl tin dilaurate.
[0072] The coating was applied at 3 mils (76.2 microns) wet film thickness to tinplate panels and a laneta card, and was allowed to cure (crosslink) at ambient conditions (77° F. and 50% relative humidity). The coating demonstrated a tack-free time of 1 hour and a dry-hard time of 3 hours. After 14 days of curing at ambient conditions, the coating demonstrated a 60° gloss of 48 GU, a resistance of 100+ double rubs to methyl ethyl ketone (MEK) solvent, and a pendulum hardness of 91 oscillations. The coating also demonstrated high flexibility, and passed a 180 degree bend test and a ¼″ Mandrel Bend test without cracking. Xenon Arc Weatherometer (WOM) testing of the coating demonstrated a color change (Delta E) of <0.5 after 2000 hours exposure.
Example 4
[0073] This example describes the preparation of a polymer based on an aliphatic polyisocyanate, N-substituted amino-functional alkoxysilanes with butyl ester-containing groups, and an aliphatic secondary diamine chain extender with N-alkyl groups. The structure is shown in FIG. 2 .
[0074] 35.5 g (0.194 equiv.) of an aliphatic polyisocyanate based on an HDI isocyanurate trimer (commercially available as Desmodur N-3600 from Bayer Material Science) was dissolved in 60 g of Aromatic 100 solvent (commercially available from Exxon) in a 500 ml 3-neck round bottom flask equipped with an Argon inlet and thermometer. This was followed by the addition of 2 g of vinyltrimethoxysilane (commercially available from Aldrich) as a drying agent. Using an addition funnel, 40 g (0.130 equiv.) of butyl 3-((3-(trimethoxysilyl)propyl)amino)propanoate (synthesized by reacting 3-aminopropyltrimethoxysilane with butyl acrylate via a Michael Addition reaction) was added dropwise to the solution while keeping the temperature at 40-50° C. Next, 4.17 g (0.064 equiv.) of N 1 ,N 3 -diethylpropane-1,3-diamine was added dropwise while continuing to keep the temperature at 40-50° C. After the addition was complete, the solution was stirred for an additional 15-30 minutes until the infrared (IR) spectra indicated that no more free isocyanate (NCO) (2270 cm −1 ) remained in solution. The polymer solution was calculated to have a solids content of 57.6% by weight.
Example 5
[0075] This example describes the preparation of a polymer based on an aliphatic polyisocyanate, N-alkyl amino-functional alkoxysilanes, and a cycloaliphatic secondary diamine chain extender with N-alkyl groups, although with different ratios than utilized in Example 1.
[0076] 81.6 g (0.446 equiv.) of an aliphatic polyisocyanate based on an HDI isocyanurate trimer (commercially available as Desmodur N-3600 from Bayer Material Science) was dissolved in 115 g of xylenes (commercially available from Aldrich) in a 500 ml 3-neck round bottom flask equipped with an Argon inlet and thermometer. This was followed by the addition of 5 g of vinyltrimethoxysilane (commercially available from Aldrich) as a drying agent. Using an addition funnel, 84.03 g (0.357 equiv.) of N-butyl-3-aminopropyltrimethoxysilane (commercially available as SIB 1932.2 from Gelest) was added dropwise to the solution while keeping the temperature at 40-50° C. Next, 12.57 g (0.0979 equiv.) of N-isopropyl-3-((isopropylamino)methyl)-3,5,5-trimethylcyclohexanamine was added dropwise while continuing to keep the temperature at 40-50° C. After the addition was complete, the solution was stirred for an additional 15-30 minutes until the infrared (IR) spectra indicated that no more free isocyanate (NCO) (2270 cm −1 ) remained in solution. The polymer solution was calculated to have a solids content of 61.4% by weight.
Example 6
[0077] A semi-gloss single-component coating composition was prepared by mixing 130.29 g of the polymer solution (80 g solid polymer by weight) in Example 5 with 11.65 g titanium dioxide, 2.9 g Shepherd Black 30C940, 1.95 g Shepherd Green 410, 1.0 g Shepherd Yellow 30C119, 30 g ceramic microspheres, 20 g of a methoxy-functional dimethylpolysiloxane (commercially available as Silres SY231 from Wacker Chemical), 5 g Oxsol 100 and 1.0 g dibutyl tin dilaurate.
[0078] The coating was applied at 3 mils (76.2 microns) wet film thickness to tinplate panels and a laneta card, and was allowed to cure (crosslink) at ambient conditions (77° F. and 50% relative humidity). The coating demonstrated a tack-free time of 3 hours and a dry-hard time of 6 hours. After 14 days of curing at ambient conditions, the coating demonstrated a 60° gloss of 48 GU, a resistance of 100+ double rubs to methyl ethyl ketone (MEK) solvent, and a pendulum hardness of 82 oscillations. The coating also demonstrated high flexibility, and passed a 180 degree bend test and a ¼″ Mandrel Bend test without cracking. Xenon Arc Weatherometer (WOM) testing of the coating demonstrated a color change (Delta E) of <0.80 after 2000 hours exposure.
Example 7
[0079] A low-gloss single-component coating composition was prepared by mixing 130.29 g of the polymer solution (80 g solid polymer by weight) in Example 5 with 15 g titanium dioxide, 0.2 g carbon black, 25 g amorphous silica, 20 g of a methoxy-functional dimethylpolysiloxane (commercially available as Silres SY231 from Wacker Chemical), 30 g xylenes and 1.0 g dibutyl tin dilaurate.
[0080] The coating was applied at 3 mils (76.2 microns) wet film thickness to tinplate panels and a laneta card, and was allowed to cure (crosslink) at ambient conditions (77° F. and 50% relative humidity). The coating demonstrated a tack-free time of 3 hours and a dry-hard time of 6 hours. After 14 days of curing at ambient conditions, the coating demonstrated a 60° gloss of 0.9 GU, a 85° gloss of 2.3 GU, a resistance of 100+ double rubs to methyl ethyl ketone (MEK) solvent, and a pendulum hardness of 56 oscillations. The coating also demonstrated high flexibility, and passed a 1″ Mandrel Bend test without cracking.
[0081] The above descriptions are those of the preferred embodiments of the invention. Various modifications and variations are possible in light of the above teachings without departing from the spirit and broader aspects of the invention. It is therefore to be understood that the claimed invention may be practiced otherwise than as specifically described. Any references to claim elements in the singular, for example, using the articles “a,” “an,” “the,” or “said,” is not to be construed as limiting the element to the singular.
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Moisture-curable single-component (1K) coatings based on N-substituted urea polymers with extended chains and terminal alkoxysilane groups. The coatings are highly flexible, are gloss retentive, provide fast tack-free and dry-through times, provide high solvent resistance, and provide excellent exterior color stability to sunlight. The coatings can be formulated to produce high-gloss, semi-gloss and low-gloss finishes, and thus have application as both commercial and military coatings.
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CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese application serial no. JP2012-137609, filed on Jun. 19, 2012, the content of which is hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an optical pickup device for use in recording/reproducing on an optical recording medium, such as a CD (Compact Disk), a DVD (digital Versatile Disk), a Blu-ray Disk (registered trademark), and, more particularly, to an adhesive fixing technique for a laser diode or a photodetector, etc.
[0004] 2. Description of the Related Art
[0005] There are some types of optical systems as an optical pickup device for use in recording/reproducing on an optical recording medium (CD, DVD) and an optical disk drive device in which the optical pickup device is embedded. As illustrated in FIG. 13 , one optical system leads output light from a light emitter 93 (laser diode (hereinafter referred to as an LD)) to an object lens through any of a lens 95 , a prism 96 , and a mirror 98 , and converges the light onto an optical disk. Another optical system causes light reflected from the optical disk to be focused on a photodetector 94 through an object lens, a reflection mirror, a prism, and a lens 97 . In these devices, the LD 93 and the photodetector 94 need to be fixed in an optically appropriately adjusted position with respect to a case 90 of the optical pickup device. Thus, generally, in the structure, the optical device (LD and photodetector 94 ) is once adhered to a holder 99 having a form suitable for adhering to the case. After the holder 99 and the case 90 are adjusted into an optically appropriate position, they are fixed in an appropriately three-dimensional position with the thickness of the adhesive agent layer, using a ultraviolet (UV) cure adhesive agent.
[0006] Variations of application positions, forms, and areas of the adhesive agent cause a variation in the adhesive strengths. In recent years, in some type of device, the case for installing the optical parts is made from a resin. This type of device is increasing. The resin case has a lower adhesive strength with the installed parts, than the adhesive strength of a metal case, and is likely to be separated at the interface. Thus, it is desired to improve the adhesive strength. Further, when an increased amount of adhesive agent is applied for the purpose of improving the adhesive agent, conventionally, a problem is that the adhesive agent may undesirably block the optical path.
[0007] Patent documents 1 and 2 are provided to disclose an optical pickup device, as prior art documents.
PRIOR ART DOCUMENTS
Patent Documents
[0008] Patent document 1: Japanese Unexamined Patent Application Publication No. 2007-226922
[0009] Patent document 2: Japanese Unexamined Patent Application Publication No. 2009-146523
[0010] In the above-described conventional techniques, Patent document 1 disclose a structure in which a through hole is formed in the adhered part, and a support is formed in the case, for the purpose of suppressing the separation of joint members and deviation of an optical axis. If the adhesive agent is applied into the through hole, it is difficult to define the amount of adhesive agent, resulting in a variation of the agent applications. Therefore, it is difficult to suppress the variation in the adhesive strength.
[0011] Patent document 2 proposes a structure in which the adhesive agent is applied into a concave groove formed in the case. However, it is difficult to control the adhesive agent overflowed from the groove, and it can be expected that the adhered areas may vary. Further, when the adhesive agent overflows onto the optical path, the optical path may undesirably be blocked.
[0012] The above-described techniques satisfy the capability of the present optical pickup device. However, the variation in the adhesive strength and the strength itself may undesirably and increasingly have an effect on the device, as the device is made thin and the adhered area is made small, from this time.
SUMMARY OF THE INVENTION
[0013] In order to solve the above problem, it is accordingly an object of the present invention to provide an optical pickup device which can suppress a variation in adhesive strengths, and can sufficiently attain the adhesive strength by increasing the adhered area on the side of the case, by defining the application positions, forms, and areas of the adhesive agent.
[0014] In order to solve the above problem, according to the present invention, there is provided an adhesive structure of an optical device, comprising: a case which has an adhesive joint to adhere the optical device; an optical device which is held by a holder and adjusted in accordance with relative positioning with the case so that an adhesive joint is opposed to the adhesive joint of the case to which an adhesive agent is applied and optically optimum sensitivity is attained for light passing through an optical path connected to the case; and an adhesive agent which is provided between the adhesive joint of the case and the adhesive joint of the optical device held by the holder, and which is formed by pressing into a predetermined thickness and hardened by ultraviolet rays, and wherein a plurality of pairs of banks are formed in positions between which an adhesive agent application area of the adhesive joint of the case is formed, and a height of a bank on a side of an optical path is higher than a height of other bank, in the plurality of banks, and the adhesive agent which is pressured in accordance with a relative positioning operation of the case and the optical device held by the holder is hardened in a state where it overflows over the other bank and is spread between the both adhesive joints.
[0015] According to the present invention, the adhesive strength can be stabilized by forming banks with different heights on the right and left sides of an adhesive agent application position of a case, and defining the application positions, forms, and areas of the adhesive agent. In addition, the adhesive strength can be improved by increasing the adhered area. Further, the projected part on the side of the optical path is formed to have a high height, thereby providing an optical pickup device which can suppress overflowing of the adhesive agent to the optical path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A-1D are adhesive process schematic diagrams each illustrating an example of an adhesive joint of an optical pickup case according to a first embodiment of the present invention and a photodetector.
[0017] FIGS. 2A-2D are adhesive process schematic diagrams illustrating an example of an adhesive joint of a conventional optical pickup case and a photodetector.
[0018] FIG. 3A is a cross sectional view of the adhesive joint of the optical pickup case of the first embodiment of the present invention and the photodetector, and FIG. 3B is a cross sectional view showing an example of the adhesive joint on the upper surface of the optical pickup case, excluding a photodetector held by a holder from the corresponding structure.
[0019] FIG. 4 is a schematic cross sectional view showing an example of an adhesive joint of an optical pickup case according to the second embodiment of the present invention and a photodetector.
[0020] FIG. 5 is a schematic cross sectional view showing an example of an adhesive joint of an optical pickup case according to a third embodiment of the present invention and a photodetector.
[0021] FIG. 6 is a schematic cross sectional view showing an example of an adhesive joint of an optical pickup case according to a fourth embodiment of the present invention and a photodetector.
[0022] FIG. 7 is a schematic cross sectional view showing an example of an adhesive joint of an optical pickup case according to a fifth embodiment of the present invention and a photodetector.
[0023] FIG. 8 is a perspective diagram showing an example, immediately after an adhesive agent is applied to the optical pickup case according to the fifth embodiment of the present invention.
[0024] FIG. 9 is a perspective diagram of an adhesive joint of the optical pickup case after alignment, according to the fifth embodiment of the present invention.
[0025] FIG. 10 is a schematic cross sectional view showing an example of an adhesive joint of an optical pickup case according to a sixth embodiment of the present invention and a photodetector.
[0026] FIG. 11 is a perspective diagram showing an example, immediate after an adhesive agent is applied to the optical pickup case according to the sixth embodiment of the present invention.
[0027] FIG. 12 is a perspective diagram of an adhesive joint of the optical pickup case after alignment, according to the sixth embodiment of the present invention.
[0028] FIG. 13A is a block diagram of an optical pickup device according to the present invention, and FIG. 13B is a diagram showing an example of an adhesive joint of a photodetector (optical device) thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Preferred embodiments of the present invention will now specifically be described using the drawings.
First Embodiment
[0030] The first embodiment will now be described using any one of FIGS. 1A-1D to FIGS. 3A-3B . In the drawings, the same constituent elements are identified by the same reference numerals.
[0031] FIGS. 2A-2D are schematic diagrams showing an example of an adhesive process and a fixed structure, when connecting an optical pickup case 1 ( 90 in FIG. 13 ) introduced in a manufacturing process of a conventional optical pickup device and a photodetector 3 ( 94 in FIG. 13 ) which is held by a holder 2 ( 99 in FIG. 13 ).
[0032] As illustrated in FIG. 2A , a flat adhesive joint 10 of the optical pickup case 1 and an adhesive joint 20 on the side of the photodetector 3 held by the holder 2 are opposed to each other so as to be set. In this case, the optical pickup case 1 is fixed with a fixing jig (not illustrated) to achieve flatness of the adhesive joint 10 . The photodetector 3 held by the holder 2 is kept by a keeping jig (not illustrated). The adhesive joint 20 (back surface of the holder 2 ) on the side of the photodetector is set in a position opposed to the above adhesive joint 10 .
[0033] As illustrated in FIG. 2B , an adhesive agent 4 is applied to the adhesive joint 10 of the optical pickup case 1 fixed with the fixing jig, using a dispenser.
[0034] After the adhesive agent 4 is applied, as illustrated in FIG. 2C , the photodetector 3 held by the holder 2 is brought in proximity within a predetermined distance of the optical pickup case 1 , for optically optimum alignment. Specifically, light emitted from an LD is received by the photodetector 3 , through cylindrical optical paths formed in the optical pickup case 1 and the holder 2 . In addition, to acquire the maximum sensitivity, the optical pickup case 1 and the photodetector 3 held by the holder 2 are positioned, and their inclination angles are adjusted, in accordance with a relative operation of the fixing jig for fixing the optical pickup case 1 and the keeping jig for keeping the photodetector 3 held by the holder 2 . Then, the adhesive joint 10 of the optical pickup case 1 and the adhesive joint 20 on the side of the photodetector are positioned, in a range of a predetermined design distance.
[0035] By implementing this position alignment, a space of approximately 0.3 to 0.7 mm is made in the adhesive joint 20 on the side of the photodetector 3 opposed to the adhesive joint 10 of the optical pickup case 1 . At the same time, the adhesive agent 4 applied to the adhesive joint 10 of the optical pickup case 1 is in contact with the opposed adhesive joint 20 on the side of the photodetector 3 , and is spread on the surface thereof.
[0036] As illustrated in FIG. 2D , after the alignment, ultraviolet rays are irradiated onto the adhesive agent 4 so as to be hardened by a ultraviolet irradiator from the side surface direction of the adhesive agent 4 between the both adhesive joints. This results in completing a process for fixing the adhesive joint 10 of the optical pickup case 1 and the adhesive joint 20 of the photodetector 3 held by the holder 2 , using the adhesive agent 4 .
[0037] The applied adhesive agents may vary in their applied positions, forms, and areas, due to viscosity change of the adhesive agent in accordance with a change in the work environment (temperature, humidity, etc.) or due to the position alignment at the adhesion. What is concerned is that these variations may cause a variation in the adhesive strengths. In these days, there is a tendency of increasing the use of products including a resin as a material for the optical pickup case. It is difficult to maintain the adhesive strength of the resin optical pickup case. Therefore, it is desired to improve the strength.
[0038] FIGS. 1A-1D and FIGS. 3A-3B are schematic diagrams each showing an example of an adhesive process and a fixed structure, when different height banks 5 of two rows are provided on both sides of the optical path 6 a of the adhesive joint 10 of the optical pickup case 1 according to the first embodiment 1 of the present invention. In this embodiment, as illustrated in FIG. 1A , banks 5 a on the side of the optical path 6 a of the adhesive joint 20 on the side of the photodetector 3 have a higher height than the other banks 5 b on the outer side. Because the banks 5 are provided, the adhesive agent 4 is applied (see FIG. 1B ) and controlled its spread position, form, and area (see FIG. 1C ), thus enabling to suppress the variation in the adhesive strengths and also improving the adhesive strength due to the increased adhered area.
[0039] In the structure where the height of the outer banks 5 b is lower than banks 5 a on the side of the optical path, any excess adhesive agent 4 overflowing at the alignment of the optical pickup case 1 and the photodetector 3 is actively overflowed from the outer banks 5 b. Thus, the adhesive agent is hardly overflowed from the banks 5 a on the side of the optical path, thus preventing the adhesive agent 5 from overflowing to the optical path 6 a (see FIG. 1D ).
[0040] FIG. 3A is a cross sectional view showing a structure in which the photodetector is adhered and fixed to the optical pickup case 1 , like the structure of FIG. 1D . FIG. 3B is a cross sectional view of an adhesive joint on the upper surface of the optical pickup case 1 , excluding the photodetector 3 held by the holder 2 from the structure. FIG. 3B is a cross sectional view showing a squeezed adhesive agent, and shows the upper surface of the banks 5 a and 5 b. In this embodiment, the banks 5 a and 5 b are freely provided, because there is no bank to prevent the adhesive agent from overflowing in a vertical direction in the illustration. This is based on an intention not to interrupt irradiation of the ultraviolet rays from ultraviolet irradiators 50 a and 50 b from both sides of the adhesive joint.
[0041] The adhesive agent 4 overflows in accordance with the height of the lower bank, so as to increase the adhered area.
[0042] As to the specific heights of the banks 5 a and 5 b, the higher bank 5 a on the side of the optical path cannot be made higher than 0.3 mm, for example, when a space of approximately from 0.3 to 0.7 mm is made between the adhesive joint 10 of the optical pickup case 1 and the opposed adhesive joint 20 on the side of the photodetector 3 . In this case, the height of the higher bank 5 a on the side of the optical path is preferably equal to or lower than 0.3 mm (lower limit value of the space between the adhesive joint 10 of the optical pickup case 1 and the opposed adhesive joint 20 on the side of the photodetector 3 ), and the height of the outer lower bank 5 b is preferably lower than the height of the higher bank 5 a on the side of the optical path. It is preferred that the height of the outer lower bank 5 b is optimized based on the predicted overflowing amount of the adhesive agent 4 at the alignment.
[0043] When there is a wide space between the adhesive joint 10 of the optical pickup case 1 and the opposed adhesive joint 20 on the side of the photodetector 3 , the height of the higher bank 5 a on the side of the optical path is preferably optimized to be equal to or lower than the lower limit value of the adhesive space, and the height of the outer lower bank 5 b is preferably optimized to be lower than the height of the higher bank 5 a on the side of the optical path. The banks 5 a and 5 b may be formed simultaneously when forming the optical pickup case 1 using a metal mold.
Second Embodiment
[0044] A second embodiment of the present invention will now be described using FIG. 4 . Those matters described in the first embodiment but not described in the second embodiments are applicable to this embodiment, unless there are special circumstances.
[0045] FIG. 4 is a schematic diagram showing another example of a fixed structure in which the banks 5 a and 5 b with different heights are provided on both sides of the optical path 6 a of the adhesive joint 10 of the optical pickup case 1 according to this embodiment. In this example, the basic structure is the same as that of FIG. 1D , but the top of the higher bank 5 a on the side of the optical path is made in a projected form in cross section. In this structure, the same effects as that of the first embodiment can be obtained. In addition, the volume of the adhesive agent 4 between the banks 5 a and 5 b increases. Thus, it is possible to prevent the adhesive agent 4 from overflowing to the optical path 6 a.
Third Embodiment
[0046] A third embodiment of the present invention will now be described with reference to FIG. 5 . Those matters described in the first embodiment but not described in this embodiment are applicable to this embodiment also, unless there are special circumstances.
[0047] FIG. 5 is a schematic diagram showing another example of a fixed structure in which the banks 5 a and 5 b with different heights are provided on both sides of the optical path 6 a of the adhesive joint 10 of the optical pickup case 1 according to this embodiment. In this embodiment, the basic structure is the same as that of FIG. 4 , but the top of the higher bank 5 a on the side of the optical path is formed in an inversed taper. In the inversed taper, an end on the side of the optical path is higher than the outer end. In this structure, the same effect as that of the first embodiment can be obtained. In addition, it is possible to further prevent the adhesive agent 4 from overflowing to the optical path 6 a for the same reason as that of the second embodiment.
Fourth Embodiment
[0048] A fourth embodiment of the present invention will now be described using FIG. 6 . Those matters described in the first embodiment but not described in this embodiment are applicable to this embodiment also, unless there are special circumstances.
[0049] FIG. 6 is a schematic diagram showing another example of a fixed structure in which the banks 5 a and 5 b with different heights are provided on both sides of the optical path 6 a of the adhesive agent 4 of the optical pickup case 1 according to this embodiment. In this example, the basic structure is the same as that of FIG. 1D . However, a cross section of the higher bank 5 a on the side of the optical path 6 a is formed in an inversed taper. In the inversed taper, the outer side surface opposed to the optical path is outwardly inclined. In this structure, the same effect as that of the first embodiment can be obtained. In addition, it is possible to suppress the interface separation in a z-axis direction, when tensile stress is generated between the adhesive agent 4 and the optical pickup case 1 .
Fifth Embodiment
[0050] A fifth embodiment of the present invention will now be described using FIG. 7 to FIG. 9 . Those matters described in the first embodiment but not described in this embodiment are applicable to this embodiment, unless there are special circumstances.
[0051] FIG. 7 is a schematic diagram showing an example of a fixed structure in which the banks 5 a and 5 b with different heights are provided on both sides of the optical path 6 a of the adhesive joint 10 of the optical pickup case 1 according to this embodiment. FIG. 8 shows a state of the adhesive joint 10 of the optical pickup case 1 to which the adhesive agent 4 is applied, before the alignment of the photodetector 3 . FIG. 9 is a diagram showing a state of the adhesive joint 10 of the optical pickup case 1 , after the alignment of the photodetector 3 .
[0052] In this example, the basic structure is the same as that of FIG. 1D , but a third bank 5 c is formed outwardly of the outer lower bank 5 b. In this structure, when the optical pickup case 1 and the photodetector 3 are aligned, it is possible to control the adhered area by blocking the adhesive agent 4 which has overflowed over the outer lower bank 5 b, using the third bank 5 c, and it is also possible to suppress the variation in the adhesive strengths. Thus, the adhesive strengths can expectedly be improved due to an increase in the adhered area. Further, with the third bank 5 c, it is possible to increase the amount of adhesive agent 4 , thus attaining the effect of the improved adhesive strengths.
[0053] The higher bank 5 a on the side of the optical path in the fifth embodiment may be formed in any form of the above-described first to fourth embodiments.
Sixth Embodiment
[0054] A sixth embodiment of the present invention will now be described using FIG. 10 to FIG. 12 . Those matters described in the first embodiment but not described in this embodiment are also applicable to this embodiment, unless there special circumstances.
[0055] FIG. 10 is a schematic diagram showing another example of a fixed structure, in which the banks 5 with different heights are provided on both sides of the optical path 6 a of the adhesive joint 10 of the optical pickup case 1 according to this embodiment. FIG. 11 shows a state of the adhesive joint 10 of the optical pickup case 1 to which the adhesive agent 4 is applied, before the alignment of the photodetector 3 . FIG. 12 shows a state of the adhesive joint 10 of the optical pickup case 1 , after the alignment of the photodetector 3 .
[0056] In this example, the basic structure is the same as that of FIG. 1D , but the length of an outer lower bank 5 d is shorter than the length of the higher bank 5 a on the side of the optical path. This outer lower bank 5 d can positively cause the adhesive agent 4 (which has overflowed at the alignment of the optical pickup case 1 and the photodetector 3 ) to be released from the both ends, and can enhance an anti-overflowing effect on the adhesive agent 4 to the optical path 6 a. Further, the adhesive agent 4 can positively be released from both ends of the shorter bank 5 d, thus enabling to decrease the amount of adhesive agent 4 overflowing over a bank center part 5 e.
[0057] The adhesive agent 4 after the alignment of the photodetector 3 can be hardened by irradiating ultraviolet rays using a UV lamp from both directions of the both sides of a space of approximately from 0.3 to 0.7 mm. This space is made between the adhesive joint 10 of the optical pickup case 1 and the opposed adhesive joint 20 on the side of the photodetector 3 . At this time, the hardening reaction of the adhesive agent 4 begins from the surface of the adhesive agent 4 near ultraviolet irradiators 50 a and 50 b, and then gradually progresses toward the center part of the adhesive agent 4 . The hardening reaction progresses while the adhesive agent 4 absorbs the irradiated ultraviolet rays. Thus, the amount of ultraviolet rays reaching the center part of the adhesive agent 4 is smaller than the amount of ultraviolet rays reaching the surface of the adhesive agent 4 . As a result, when the hardening reaction unevenly progresses between the surface and the center part of the adhesive agent 4 , it is well known that the shrinkage is unevenly generated at the hardening, thus resulting in a factor of optical deviation.
[0058] It is preferred that the surface and the center part of the adhesive agent 4 are evenly hardened. In the center part, in which a smaller amount of ultraviolet rays reach than an amount of ultraviolet rays reaching the circumferential part, the amount of remaining adhesive agent 4 is preferably small for the purpose of suppressing the optical deviation.
[0059] Therefore, by causing the adhesive agent 4 to positively be released from both sides of the shorter bank 5 d, the amount of adhesive agent 4 remaining in the bank center part 5 e can be reduced, thereby enabling to suppress the optical deviation of the photodetector 3 .
[0060] The form of the higher bank 5 a on the side of the optical path 6 a in the sixth embodiment may be in any form described in the above-described embodiments, and may be configured in combination with the third bank 5 c in the fifth embodiment.
[0061] The descriptions have been made to the optical pickup device according to the preferred embodiments of the present invention. However, the present invention is not limited to the above-described embodiments.
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In an optical pickup device for use in recording and reproducing on an optical recording medium, such as a CD or DVD, banks are formed on both sides of an adhesive agent application position for adhering an optical device, such as a photodetector or a laser diode, in an optical pickup case. At this time, a bank on the side of an optical path is formed higher than a height of an outer bank, and an adhesive agent is poured between the banks, to adhere the optical pickup case and the optical device.
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SPECIFICATION
[0001] The present invention refers to an apparatus for the automatic removal of tubular textiles, to be used especially, although not exclusively, in plants for the production of stockings, socks and pantyhose articles.
BACKGROUND OF THE INVENTION
[0002] It is known that the sewing steps relating to the assembly or closing of the toe portions of garments such as stocking, socks and pantyhose articles, include the positioning of blank tubular products (with the toe still to be sewn) at the inlet sections of suitable machines, provided with sewing means, generally known as “line-closer” and “toe-closer” machines. The said positioning must be operated so that the blank tubes result oriented in preset and constant direction. For example, the loading of unfinished products onto the shape of a line-closer must be made so that the respective elastic hem portions (opposite to the toes) will result ahead of the toe portions.
[0003] Documents EP 508014 and U.S. Pat. No. 6,386,801 describe apparatuses for the removal of blank products from a container in which they are disposed in bulk and for the subsequent orientation thereof according to a predetermined direction.
[0004] These apparatuses result relatively expensive and complex in relation to the current production requirements, especially in relation to productions which suffer from limited investments in machine and equipment.
SUMMARY OF INVENTION
[0005] The main object of the present invention is to overcome the said drawbacks.
[0006] This result has been achieved, according to the invention, by adopting the idea of making an apparatus having the characteristics disclosed in the independent claims. Further characteristics being set forth in the dependent claims.
[0007] The present invention makes it possible to automatically feel machines for the production of stockings, socks and pantyhose articles by means of an apparatus which is easy to make, cost-effective and reliable even after a prolonged service life.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] These and other advantages and characteristics of the invention will be best understood by anyone skilled in the art from a reading of the following description in conjunction with the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein:
[0009] [0009]FIG. 1 is a schematic perpective view of an apparatus according to the invention;
[0010] FIGS. 2 A- 2 D is a plan view of four different types of articles able to be processed by the apparatus of FIG. 1;
[0011] [0011]FIG. 3 is a schematic front view of the apparatus;
[0012] [0012]FIG. 4 shows a detail relative to a modified embodiment of the platform for the containers;
[0013] [0013]FIG. 5 is a schematic diagram of the system for the programmable control of motions;
[0014] [0014]FIG. 6 is a schematic side view of the apparatus;
[0015] [0015]FIG. 7 is a schematic side view of the device for the removal of articles;
[0016] FIGS. 8 A- 8 D shows schematically the operation of a device for controlling the orientation of the articles.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Reduced to its basic structure, and reference being made to the figures of the attached drawings, an apparatus for the automatic removal of tubular textiles according to the invention, comprises a tube ( 1 ) with substantially vertical axis, which is movable in both directions according to its longitudinal axis (double arrow “V”) and is associated with suction means (AS) to allow a vacuum to be operated thereinside.
[0018] For the said movement of tube ( 1 ) use can be made of a device comprising a carriage ( 101 ) associated with a corresponding motor member ( 100 ) to which the tube ( 1 ) is fixed: the said carriage ( 101 ) being mounted for sliding on corresponding straight guides provided inside a supporting metal frame ( 12 ) which has a development mostly vertical.
[0019] Mounted below the tube ( 1 ) is a unit for supplying articles ( 2 ), this unit comprising a plurality of containers ( 3 ) which are located onto a platform ( 30 ) bi-directionally movable (double arrow “O”) orthogonally to the tube ( 1 ), so that the movement of the platform ( 30 ) will interest in the same manner also the containers ( 3 ) supported thereon.
[0020] Disposed in overlapping relation, that is, piled up inside each container ( 3 ), are a plurality of articles ( 2 ) all being equally oriented in a preset direction. For example, in case the articles are tubular textiles to be assembled for making pantyhose articles, that is, tubular textiles with an elastic end of greater thickness ( 2 a ) and an opposite, thinner, toe end ( 2 b ), they can be located in the containers ( 3 ) all oriented with the elastic hem portion ( 2 a ) facing the tube ( 1 ) as shown in FIG. 1. The positioning of the articles ( 2 ) in the containers ( 3 ), oriented as above indicated, can be made by hand.
[0021] For example, the platform ( 30 ) can be made up of a table or plate, with an upper plane for supporting the containers ( 3 ), and mounted on guide rails extending transverse to the axis of tube ( 1 ), that is, in the direction (V) of the movement of containers ( 3 ), the said table or plate being associated with a corresponding electric motor ( 300 ) via a belt or chain transmission or through gears (not shown in the drawings).
[0022] Alternatively, the platform ( 30 ) may consist, as shown schematically in FIG. 4, of the surface of a belt oriented in the said direction (V) and engaged with two pulleys ( 31 ) to allow the movement thereof between two limit positions under control of an electric motor ( 301 ).
[0023] Inserted in the circuit connecting the suction means (AS) with the tube ( 1 ) is a vacuometer ( 13 ), whose operation will be described later.
[0024] The said actuators or electric motors ( 100 , 300 , 301 ), the suction means (AS) and the vacuometer ( 13 ) are associated with electronic programmable means (UE) to allow the intervention thereof in a manner to be described below.
[0025] The said programmable means (UE) may be of a type known to those skilled in the field of industrial automation and, therefore, will not be described in greater detail.
[0026] The operation of the apparatus, as far as the removal of articles ( 2 ) is concerned, is as follows.
[0027] The central unit (UE) drives the motor ( 100 ) to lower the tube ( 1 ) until the mouth ( 10 ) thereof results disposed in correspondence of the article ( 2 ) which is on top within the container of interest, that is, positioned in correspondence of the tube ( 1 ). The contact between the mouth ( 10 ) of tube ( 1 ) and the fabric of the article ( 2 ) is detected by the vacuometer ( 13 )—in a much as the said contact corresponds to a pressure change in the circuit (C)—connecting the suction means (AS) with tube ( 1 ), and such pressure change is detected by the vacuometer ( 13 ) connected with the programmable unit (UE).
[0028] At this point, the unit (UE) operates the reversal of rotation direction of motor ( 100 ), which causes the tube is ( 1 ) to be lifted and the article ( 2 ) to be removed from the respective container ( 3 ). Upon this step, the article ( 2 ) results hanging down while adhering to the mouth ( 10 ) of tube ( 1 ) on the side of the elastic hem ( 2 a ), whereas the toe portion ( 2 b ) is free. The lifting travel of the tube ( 1 ) is of such an extent as to move the free end ( 2 b ) of the article to the level of a stationary conduit ( 4 ) also associated with the suction means.
[0029] When the free end ( 2 b ) of the article ( 2 ) passes, during said lifting step, an optical barrier ( 5 ) located at a preset distance from the platform ( 30 ) and orthogonally oriented to the axis of tube ( 1 ), the central unit (UE) deactivates the suction within the tube ( 1 ) and activates it within the conduit ( 4 ), so that the article ( 2 ) results sucked into the latter and moved away along a conduit ( 40 ) at the end of which a station (S) may be provided for the treatment of the article. For example, the said station (S) may be one provided with a device for opening the elastic hem ( 2 a ), such as described in the U.S. Pat. No. 6,155,466.
[0030] When the vacuometer does not detect any pressure change (for example, owing to the fact that the container ( 3 ) has been emptied out), then the unit (UE) operates the lowering and subsequent lifting of tube ( 1 ) for a preset number of times (for example, two times), therafter, if the vacuometer ( 13 ) does not detect pressure changes yet in the pneumatic circuit of tube ( 1 ), the unit (UE) activates the motor ( 300 ; 301 ) to drive the platform ( 30 ) into translation to the right or to the left (depending on the selections being made in advance when setting the relevant program) by such a travel able to bring another container ( 3 ) in correspondence of the tube ( 1 ). The containers ( 3 ), as they are emptied out, can be filled again while one of them is still in use.
[0031] Downstream of said removal device, that is, intermediate between the latter and said station (S), a device ( 6 ) can be advantageously provided for controlling and checking the articles.
[0032] According to the example schematically shown in FIGS. 8 A- 8 D, the control device ( 6 ) may be of a type comprising a tubular chamber ( 60 ), with a section (I) for the admission of the articles and a section (U) for the exit thereof, with the inlet section (I) being connected with the outlet of tube ( 1 ), and with the exit section (U) which discharges on the station (S) through the conduit ( 40 ).
[0033] Mounted inside said chamber ( 60 ) is a gate ( 61 ) in proximity of the exit section (U), the gate ( 61 ) being rotatively movable under control of a corresponding rotary actuator ( 600 ), between a lifted position which uncovers the opening of exit (U) and a lowered position which closes it.
[0034] Also provided in proximity of exit section (U) is a small pneumatic piston ( 62 ) whose rod is oriented towards the same section (U).
[0035] Also mounted inside the chamber ( 60 ), but on the section (I) for the admission of articles, is a vertical gate valve ( 63 ) associated with a corresponding pnematic actuator ( 64 ) whose travel is such that, when the gate ( 63 ) is fully lowered, the same gate results in front of the lower base of chamber ( 60 ); and between the lower edge of gate ( 63 ) and said base of chamber ( 60 ) an opening is provided which allows the transit therethrough of the whole article's fabric (included the toe portion) except for the elastic hem ( 2 a ). Intermediate between the gates ( 61 ) and ( 63 ) is a conduit ( 65 ) whose mouth is disposed within the tubular chamber ( 60 ) for a purpose to be described below.
[0036] The operation of the control device above discussed is as follows.
[0037] When an article ( 2 ) arrives at the chamber ( 60 ) through the conduit ( 4 ), the gate ( 61 ) is lowered, so that the article stops. The transit of the article through the section (I) of chamber ( 60 ) and its presence upstream of gate ( 61 ) are detected by photocells ( 66 , 67 ) connected to the central unit (UE).
[0038] The enabling command of photocell ( 67 ) activates the actuator ( 62 ) so that the respective rod blocks the fabric of the article upon the surface of gate ( 61 ), as shown in FIG. 8A.
[0039] At this point, the suction operated within the chamber ( 60 ) is reversed, that is, is directed from section (U) to section (I) of chamber ( 60 ). This causes the article to be stretched over the mouth of conduit ( 65 ) and below gate ( 63 ). The latter is then lowered (as in FIG. 8B), the rod of actuator ( 62 ) is retracted, and the suction activated inside the conduit ( 65 ).
[0040] Accordingly, if the elastic hem, as shown in FIG. 8C and according to the program being set, results upstream of gate ( 63 ), as a consequence of how the article has been picked up from the respective container ( 3 ), then the gate ( 63 ) retains the same article, whose elastic hem has a volume larger than the opening available below the lower edge of gate ( 63 ), while the rest of the article enters the conduit ( 65 ). This event is detected by photocell ( 66 ), then the gate ( 61 ) is lifted, the suction is activated in the conduit ( 40 ) and deactivated in conduit ( 65 ), and the gate ( 63 ) is lifted, so that the article transits through the section (U) of chamber ( 60 ) with its elastic hem ( 2 a ) facing ahead as in FIG. 8D.
[0041] If, on the contrary, the article arrives with the elastic portion ( 2 a ) turned forwards because, for example, has been located back-to-front inside a container, the article goes completely through the conduit ( 65 ) when the suction is activated therein, so that the article is not retained in any point of gate ( 63 ) and, through the same conduit, it is unloaded on a point ( 68 ) of collection of articles which do not arrive at station (s).
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An apparatus for the automatic removal of tubular textiles, particularly for the production of stockings, socks and pantyhose articles; the apparatus comprises a plurality of containers ( 3 ), each of which contains a predetermined number of articles ( 2 ) all being equally oriented, and is supported by a motor-driven platform ( 30 ) to allow moving each container betwee a position of automatic removal of the articles and a different, standby or filling position.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an interference measurement and evaluation system, more particularly relates to an interference measurement and evaluation system for estimating a receiving line quality characteristic due to nonlinear interference, reception thermal noise power, leakage power from an adjacent channel, etc. In a communication or broadcasting system using radio waves or optical communications.
[0003] 2. Description of the Related Art
[0004] Wireless communication systems mainly suffer from mutual interference not only between terrestrial mobile wireless systems and terrestrial fixed wireless systems, but also between commercial wireless systems for space and mobile satellite communication systems. These mutual interferences include linear interference due to leakage power from adjacent or next-to-adjacent areas or linear interference due to frequency sharing and nonlinear interference where intermodulation distortion occurs due to high level interference power. In areas where the service area are broad and many systems coexist, the study of nonlinear interference has been becoming important. These are also present in optical communications and broadcasting.
[0005] For example, in areas with a coexistence of wireless systems such as conventional mobile wireless communication systems together or a mobile wireless communication system, terrestrial fixed microwave communication system, and mobile satellite communication system, the line quality has been evaluated by the leakage power of the linear parts of interference waves, filtering at the receiving side, the modulation/demodulation scheme, etc., but the nonlinear interference has not been sufficiently evaluated.
[0006] Further, while the performance relating to nonlinear interference in a receiver by themselves and individual specifications inside apparatuses of interfered wireless systems have been known, there has never been a means for estimating the above specifications as overall receiver performance in a transmitter and a receiver system.
[0007] Nonlinear distortion has been analytically verified in the past. In this, using mathematical algorithms and introducing the third-order intercept point input level (IIP3) technique, the spread of an intermodulation product (IM) spectrum by a modulated wave, the occurrence of an interference wave due to IM, and the sensitivity suppression have been studied (for example, see “Study of Nonlinear Interference Theory Relating to Wide Band Mobile Wireless System and Narrow Band Mobile Wireless System”, Journal of the EIAJ, EIAJ, RCS2002-140, Aug. 22, 2002, and “Intercept Point and Undesired Responses”, JEEE Transaction on Vehicular Technology, vol. VT32, no. 1, February 1983).
[0008] Summarizing the problems to be solved by the invention, as explained above, in the past, sufficient nonlinear distortion was not taken against nonlinear interference, so there was the problem that it was not possible to analyze the cases of occurrence of nonlinear distortion due to nonlinearity of a receiver and power of the interfering wave, the frequency interval between the desired wave and interference wave, etc., so as to reduce the frequency of occurrence and deterioration of quality in the service area.
SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide an interference measurement and evaluation means for accurately estimating an interference characteristic of a receiving side including nonlinear interference for a communication or broadcasting system using radio waves or optical communication
[0010] Another object of the present invention is to provide an interference measurement and evaluation system enabling analysis of the frequency of occurrence of nonlinear interference for a wireless communication system.
[0011] Still another object of the present invention is to provide an interference measurement and evaluation system using a nonlinear interference theoretical curve linked with a reception line quality characteristic for estimation of a reception characteristic under nonlinear interference, estimation of reception thermal noise power, estimation of the ratio between a third-order distortion coefficient a 1 and first-order coefficient a 1 due to nonlinear interference or third-order intermodulation (TTP3), or estimation of leakage power from an adjacent channel etc.
[0012] To attain the above object, according to the present invention, there is provided an interference measurement, and evaluation system comprised of a transmitting means for transmitting a digitally modulated signal from a modulated wave signal received from the transmitting means, and an interference characteristic estimating means for estimating an interference characteristic including a nonlinear interference characteristic by which the received modulated wave signal is affected from an interference signal for the received modulated wave signal due to the nonlinear characteristic of the receiving means, the interference characteristic estimating means referring to a level of the modulated wave signal received by the receiving means, a level of the interference signal, and a nonlinear interference theoretical curve given in relation to a line quality of a modulated signal decoded by the receiving means and estimating the interference characteristic including the nonlinear characteristic possessed by the receiving means based on the measured level of the modulated wave signal, level of the interference signal, and line quality of the decoded modulated signal.
[0013] According to this interference characteristic estimating means, the interference characteristics due to a nonlinear interference wave of a receiving means in a communication or broadcasting system using radio waves or optical wave can be accurately quantized and estimated in advance, so it is possible to accurately estimate specifications from a nonlinear interference theoretical curve as overall performance of reception even when the performance of the reception even when the communication system relating to nonlinear interference and the specifications inside an apparatus of the interfered wireless system are unknown, therefore possible to flexibly estimate the line quality for a wireless communication system under nonlinear interference envisioning a real environment and possible to take measures to prevent deterioration of line quality.
[0014] These and other effects are considered the same for an optical communication or broadcasting system etc.
[0015] Preferably, the interference characteristic measuring means estimates the nonlinear interference characteristic possessed by the receiving means based on the modulated wave signal of the region where the nonlinear interference is dominant when the nonlinear interference theoretical curve satisfies a predetermined line quality and based on the received level of the interference signal.
[0016] Since it is possible to accurately estimate an interference characteristic including nonlinear interference possessed by the receiving means, it is possible to prevent deterioration of the line quality in wireless communication under nonlinear interference.
[0017] More preferably, the receiving means is provided with a receiving side interfered digital wireless means receiving a composite signal of a modulated wave signal from the transmitting means and an interference signal from the nonlinear interfering means and an error rate measuring means for measuring an error rate in the composite signal, and the predetermined line quality is a bit error rate free from an effect of leakage power, dominated by the nonlinear interference region, and measured by the error rate measuring means.
[0018] Since it is possible to accurately estimate the bit error rate possessed by the receiving means, it is possible to prevent deterioration of the bit error rate in wireless communication under nonlinear interference condition.
[0019] More preferably, the transmitting means is provided with a transmitting side variable attenuating means for changing the transmitted signal level and the nonlinear interference characteristic possessed by the receiving means is estimated by changing the transmitted signal level by the transmitting side variable attenuating means.
[0020] Due to this, the received signal level changes in accordance with a change in the transmitted signal level, the received level when the nonlinear interference theoretical curve relating to the change satisfies a predetermined line quality, and as a result the nonlinear interference characteristic can be accurately estimated, so the detrimental effect of nonlinear interference on the receiving side can be accurately prevented.
[0021] More preferably, the transmitting means and the receiving means are provided between them with a nonlinear interfering means having a carrier frequency different from a frequency region of the transmitting means and giving a nonlinear interference wave signal having a non negligible level compared with the level of the modulated carrier transmitted from the transmitting means, the transmitting means is provided with a transmitting side variable attenuating means for changing the interference signal level, and the nonlinear interfering means is provided with an interfering side variable attenuating means for changing the level of the interference signal, and the transmitting side variable attenuating means and the interfering side variable attenuating means are adjusted to make the ratio of the transmitting signal level and the level of the interference signal constant and give it to the receiving side interfered digital wireless means, whereby the nonlinear characteristic possessed by the receiving means is estimated.
[0022] Since the received level is estimated when the nonlinear interference theoretical curve, that relates to a change in the received signal level when the ratio between the transmitted signal level and the level of the interference signal is constant, satisfies a predetermined line quality. As a result, the nonlinear interference can be accurately estimated, and the detrimental effect of nonlinear interference on the receiving side can be accurately prevented.
[0023] More preferably, the receiving means is provided with a receiving side variable attenuator for changing an input signal level from the transmitting means and changes the input signal level so as to estimate the nonlinear interference characteristic possessed by the receiving means.
[0024] Due to this, it is possible to estimate the nonlinear interference characteristic at any received signal level.
[0025] Still more preferably, the interference characteristic estimating means estimates a thermal noise power based on the nonlinear characteristic given to the receiving means based on the received signal level of the region where the received thermal noise power is dominant when the nonlinear interference theoretical curve satisfies a predetermined line quality.
[0026] Since the thermal noise power based on the nonlinear characteristic given to the receiving means can be accurately estimated, the minimum received level given by the thermal noise on the receiving side is accurately determined without nonlinear interference.
[0027] More preferably, the nonlinear interfering means is provided with a frequency converting means for converting a center frequency of a nonlinear interference wave, and the interference characteristic estimating means estimates a received equivalent band limitation characteristic possessed by the receiving means when converting the center frequency of the nonlinear interference wave by the frequency converting means.
[0028] Since the received equivalent band limitation characteristic possessed by the receiving means can be estimated, it becomes possible to suitably set the band limitation characteristic of the receiving means.
[0029] Still more preferably, the interference characteristic estimating means estimates a leakage power of the receiving means based on a received signal level of a region where a leakage power is dominant when the nonlinear interference theoretical curve satisfies a best line quality.
[0030] Since it is possible to estimate the leakage power of the receiving means under nonlinear interference, measures can be taken to reduce the leakage power.
[0031] Still more preferably, the interference characteristic measuring means is provided with a frequency converting means for converting a center frequency of an interference signal, and the interference characteristic estimating means finds a receiving side input level giving the best line quality characteristic and its line quality based on a receiving side input level receiving line quality characteristic of the modulated wave signal for an offset frequency of the interference signal when converting the center frequency of the interference signal by the frequency converting means and the nonlinear interference theoretical curve and estimating the received equivalent leakage power for the offset frequency of the receiving side as a whole using this.
[0032] Since it is possible to estimate the leakage power of the receiving means even when the frequency of the interference signal changes, measures can be taken to reduce the leakage power.
[0033] Still more preferably, when measured values of a receiving side input level and a received line quality characteristic linked with the nonlinear interference theoretical curve are discrete, the means finds by approximation the receiving side input level giving the best line quality characteristic and that received line quality and estimates the received equivalent leakage power with respect to the offset frequency of the receiving means by this.
[0034] Since it is possible to estimate the leakage power of the receiving means in accordance with a change in the center frequency of the interference signal even if the measured values are discrete, measures can be taken to reduce the leakage power.
[0035] More preferably, the interference characteristic estimating means estimates the line quality characteristic of the receiving means with respect to an interference signal including a nonlinear interference wave of any frequency and of any level based on the nonlinear interference theoretical curve, a thermal noise power estimated given to the receiving means based on a received signal level of a region where the received thermal noise power is dominant when the nonlinear interference theoretical curve satisfies a predetermined line quality, and the equivalent leakage power.
[0036] Since it is possible to estimate the line quality characteristic of the receiving means for an interference signal of any frequency and of any level, it is possible to take measures to prevent deterioration of the line quality of the receiving means due to an interference signal.
[0037] Preferably, the interference characteristic estimating means estimates by approximation an interference characteristic including a nonlinear interference characteristic possessed by the receiving means based on a line quality of a decoded signal of a discrete receiving side input level versus modulated wave signal characteristic of a modulated wave signal from a state where there is no signal giving nonlinear interference to the receiving means to a state giving nonlinear interference.
[0038] Since the interference characteristic including a nonlinear interference characteristic possessed by the receiving means is estimated by approximation based on the discrete measured values of the received level of the receiving means and the line quality even if there is no signal giving nonlinear interference to the receiving means, the limitation on the frequency of the interference signal is eased and estimation of the interference characteristic becomes easy.
[0039] Preferably, the interference characteristic estimating means estimates the nonlinear interference of the receiving means based on a region where an adjacent power dominates and a received level of a region where the received thermal noise dominates in the nonlinear interference theoretical curve.
[0040] Since it is possible to estimate a nonlinear interference characteristic of the receiving means even without measuring the received level at a region where the interference power is dominant, estimation of the nonlinear interference characteristic becomes easy.
[0041] More preferably, the interference characteristic estimating means estimates the nonlinear interference characteristic of the receiving means based on the nonlinear interference theoretical curve and the estimated thermal noise power even when the modulated wave signal and the interference signal approach each other in frequency to an extent where the adjacent power increases.
[0042] Since it is possible to estimate the nonlinear interference characteristic of the receiving means even when the modulated wave signal and the interference signal are close in frequency, estimation of the nonlinear interference characteristic becomes easy.
[0043] Summarizing the above, in the present invention, the nonlinear interference is expressed as the nonlinear characteristic of the interfered reception system by a 3 /a 1 or the intercept point input level (IIP), the third-order distortion of the receiving characteristic is linked with the bit error rate (BER) as one example of the line quality from the interference leakage power from a 3 /a 1 or the intercept point input level IIP3 and the reception system thermal noise, estimation of the a 3 /a 1 or the intercept point input level IIP3 of reception as a whole, which was difficult to quantize in the past, is made possible, provision is made of a means for more accurately providing the line quality under nonlinear interference from the estimated a 3 /a 1 or IIP3, and a good line quality is made possible,
[0044] The above explanation was mainly mad regarding a wireless communication system, but the invention can also clearly be similarly applied to a communication system or broadcasting system using light.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] These and other objects and features of the present invention will become clearer from the following description of the preferred embodiments given with reference to the attached drawings, wherein:
[0046] [0046]FIG. 1 is a block diagram of the configuration of an interference measurement and evaluation system according to a first embodiment of the present invention,
[0047] [0047]FIG. 2A is a view of an example of a spectrum of an input signal (modulated wave signal) input to a receiving means, while FIG. 2B is a view of the spectrum of an output signal output from the receiving means in response to the input signal shown in FIG. 2A,
[0048] [0048]FIG. 3 is a graph for explaining the levels of a main signal, third-order distortion signal, and fifth-order distortion signal when the receiving side receives as input two signals of the same level close in frequency,
[0049] [0049]FIG. 4 is a graph for estimating an intercept point from the relationship between an input level and output level at the receiving side,
[0050] [0050]FIG. 5A is a view of an example of the spectrum of an input signal (modulated wave signal) input to a receiving means, while FIG. 5B is a view of the spectrum of an output signal for explaining an increase in adjacent leakage power due to an interference wave intermodulation product output from a receiving means in response to the input signal shown in FIG. 5A.
[0051] [0051]FIG. 6 is a graph of an example of a bit error rate characteristic as an example of a line quality characteristic under nonlinear interference measured by using the interference measurement and evaluation system shown in FIG. 1 as a test system,
[0052] [0052]FIG. 7 is a block diagram of the configuration of an interference measurement and evaluation system according to a second embodiment of the present invention,
[0053] [0053]FIG. 8 is a graph of an example of the bit error rate characteristic under nonlinear interference measured by using the test system shown in FIG. 7,
[0054] [0054]FIG. 9 is a view of a thermal noise characteristic under nonlinear interference measured by using an interference wave power as a parameter,
[0055] [0055]FIG. 10 is a view of a thermal noise characteristic under nonlinear interference measured by using an interference wave power as a parameter,
[0056] [0056]FIG. 11 is a block diagram of the configuration of an interference measurement and evaluation system according to a third embodiment of the present invention,
[0057] [0057]FIG. 12 is a graph of an example of estimation of an equivalent attenuation of power of a receiving side when changing the frequency interval of an interference signal and interfered wave under nonlinear interference measured by using the interference measurement and evaluation system shown in FIG. 11,
[0058] [0058]FIG. 13 is a graph of an example of estimation of an equivalent leakage power of a receiving side under nonlinear interference measured by using an interference measurement and evaluation system shown in FIG. 1,
[0059] [0059]FIG. 14 is a graph of the bit error rate characteristic under nonlinear interference measured by using the test system shown in FIG. 7, and
[0060] [0060]FIG. 15 is a graph of the bit error rate characteristic under nonlinear interference in a 10th embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0061] Preferred embodiments of the present invention will be described in detail below while referring to the attached figures. Note that in the following explanation, the same reference numerals indicate the same elements.
[0062] First Embodiment
[0063] [0063]FIG. 1 is a block diagram of the configuration of an interference measurement and evaluation system according to a first embodiment of the present invention. In the figure, 11 is an error rate measuring equipment (transmitting side), 12 is an interfered digital wireless equipment (transmitting side), 13 is a variable attenuator for controlling the transmission output level of the interfered digital wireless equipment 12 , 14 is a signal generator for generating a modulated signal of an interfered digital wireless equipment, 15 is an interfered digital wireless equipment (transmitting side), 16 is a variable attenuator for controlling the transmission output level of an interfered digital wireless equipment, 17 is a hybrid composition circuit for combining a modulated wave signal output which is output from the interfered digital wireless equipment 12 and passes through the variable attenuator 3 and a modulated wave signal output which is output from the interfered digital wireless equipment 15 and passes through the variable attenuator 16 , 18 is an interfered digital wireless equipment (receiving side), 19 is an error rate measuring equipment (receiving side), and 20 is an interference characteristic estimating means including a nonlinear interference characteristic provided according to an embodiment of the present invention.
[0064] The error rate measuring equipment 11 , interfered digital wireless equipment 12 , and variable attenuator 13 constitute a transmitting means 101 . The interfered digital wireless equipment 18 and the error rate measuring equipment 19 constitute a receiving means 102 . The interfered modulated signal generator 14 , interfered digital wireless equipment 15 , variable attenuator 16 , and hybrid composition circuit 17 constitute a nonlinear interfering means 103 .
[0065] The interference characteristic estimating means 20 may be realized by any control device such as a microprocessor.
[0066] In the present embodiment, the interference measurement and evaluation system is configured as an error rate characteristic test system having a variable attenuator 13 (transmitting side variable attenuating means) for making the power of the interference wave constant and changing the input level of a modulated wave 102 and measuring the error rate of a wireless communication line under interference. The interference characteristic estimating means 20 utilizes a nonlinear interference theoretical curve know in advance, establishes correspondence of the receiving side input level of a modulated wave signal and reception bit error rate as an example of line quality as measured values with the above nonlinear interference theoretical curve, and estimates a nonlinear interference characteristic of the receiving side.
[0067] Note that the line quality characteristic is not limited to the bit error rate and may also be a frame error rate, block error rate, packet error rate, etc.
[0068] [0068]FIG. 2A is a view of an example of a spectrum of an input signal (modulated wave signal and interference signal) input to a receiving means 102 , while FIG. 2B is a view of the spectrum of an output signal output from the receiving means 102 in response to the input signal shown in FIG. 2A. In the illustrated example, for simplification of the explanation, the frequency of the interfered wave signal in the input signal is the unmodulated f cl , and the interference signal is a modulated continuous spectrum having f C2 as a center frequency and having a 2f m1 bandwidth, but the interfered wave signal and the interference signal may also be an unmodulated frequency or have a modulated continuous frequency band.
[0069] The output signal spectrum, as shown in FIG. 2B, shows the occurrence of an interference wave having a bandwidth of ±f m1 about the basic frequency f m1 of the interference wave and the occurrence of an interference wave having a bandwidth of ±2f m1 about the frequency f c1 of the side band wave of the interference wave. FIG. 2D shows the interference bandwidth ±3f m1 due to the interfered wave signal centered about the center frequency f C2 of the interference signal.
[0070] The radio D/U between the output level D (desired) of the basic frequency of an output signal at the basic frequency and an output level U (Undesired) express the degree of interference distortion. The smaller the D/U ratio, the larger the interference distortion. The present invention provides an interference evaluation system for estimating the nonlinear interference at this D/U ratio.
[0071] [0071]FIG. 3 is a graph for explaining the levels of a main signal, a third-order distortion signal, and a fifth order distortion signal in the case of receiving as input at a receiving side two signals of the same level with close frequencies. In FIG. 3, when the two basic signals (P t ) of the close frequencies f al and f a2 are input, third-order distortion of a level P IM3 is caused by frequencies of 2 a2 -f al and 2f a1 -f a2 and fifth-order distortion of a level P IM3 is caused by frequencies of 3f a2 -2f a1 and 3f a1 -2f a2 .
[0072] [0072]FIG. 4 is a graph for estimating an intercept point from a relationship of the input level and output level at a receiving side. In FIG. 4, the line “a” shows the relationship between the input levels and output levels of the two basic signals, the line “b ” shows the relationship between of the output level of the third-order distortion IM (intermodulation) with respect to the input level of the basic signal, and the line “c” shows the relationship of the output level of the fifth-order distortion IM (intermodulation) with respect to the input level of the basic signal. If the levels of the two basic signals are simultaneously raised, the difference IM 3 (see FIG. 3) between the level P t of the basic signal and the level P IM3 of the third-order distortion signal will gradually become smaller. The output of the receiving side in an actual wireless communication system becomes saturated as shown by the solid line in the figure, but if assuming that the output level increases linearly in proportion to the input level, the line “b” showing the third-order distortion will intersect with the part shown by the broken line of the basic signal. The output level at the intersection point is called the “third-order intercept point output level”, while the input level is called the “third-order intercept point input level”. The present invention estimates this third-order intercept output level or third-order intercept input level by the interference characteristic estimating means 20 .
[0073] This estimating technique will be explained below.
[0074] If expressing the baseband of an interference signal of an interfering means 103 (hereinafter called the “interfering side”) by g(L), designating the in-phase component by I(t), designating the orthogonal component by Q(t), and designating the carrier of the mobile wireless equipment of the transmitting means 101 (hereinafter called the “interfered side”) the unmodulated wave of the frequency f al as shown in FIG. 2, the input signal to the receiving means 102 (receiving side) is expressed by equation (1):
x ( t )= V 1 ·cos (π t C2 t ) +Q ( t ) ×sin (2π f C2 t ) (1)
[0075] where,
[0076] V 1 : carrier voltage of mobile wireless equipment of interfered side
[0077] f al : carrier frequency of mobile wireless equipment of interfered side
[0078] T(t): modulated signal voltage of in-phase component of baseband of mobile wireless equipment of interfering side
[0079] Q(t): modulated signal voltage of orthogonal component of baseband of mobile wireless equipment of interfering side
[0080] f a2 : carrier frequency of mobile wireless equipment of interfering side
[0081] Further, it setting g(t)={I(t) a +O(t) a } ½ and θ(t)=arctan {Q(t)/I(t)}, this is converted to the following equation (2):
x ( L ) −V 1 ·cos (2 πf c1 t ) ×cos (2 πf C2 t+O ( t )) (2)
[0082] Here,
[0083] g(t): modulated signal composite voltage of baseband of mobile wireless equipment of interfering side
[0084] θ(t): phase of carrier frequency of mobile wireless equipment of interfering side
[0085] Further, if expressing g(t) by the spectrum component, this becomes the following equation (3):
g ( t )=Σ V 2 ( k ) ×cos ( k ·2 πΔf m ·t+Δθ k ) (3)
[0086] [l<k<n]
[0087] Here,
[0088] V 2 (k): k-th modulated signal voltage of baseband of mobile wireless equipment of interfering side
[0089] Δf m : modulated frequency interval of baseband of interfering side
[0090] Δθ k : phase of modulated frequency of mobile wireless equipment of interfering side
[0091] Fm=n×Δt m : maximum modulated frequency of mobile wireless equipment of interfering side
[0092] If expressing the input signal of the receiving side amplifier as x(t) and the output signal as y(t) and expressing the nonlinear characteristic by power series expansion, the following equation (4) is obtained:
y ( t ) =a,x ( t ) +a 3 x ( t ) 2 −a 3 x ( t ) 3 (4)
[0093] Here, a 1 , a 2 , a 3 . . . are coefficient of power series expansion, and the sign of the third-order coefficient a 3 is made a minus sign from the saturation characteristic of the amplifier.
[0094] When f c2 −f c1 >3f m by the frequency array shown in FIG. 2, the nonlinear interference of a narrow band mobile wireless equipment expressed by the unmodulated wave (frequency f c1 ) is expressed by the sensitivity suppression of the output signal of the receiving side of the frequency f c2 , the power ratio (C/1 3 ) of the power C of the frequency f c1 at the output signal of the receiving side of the power 1 3 of the third-order nonlinear intermodulation component (maximum modulation frequency 2f m ) of the modulated signal of the broad band mobile wireless equipment relating to the frequency f c1 , etc. Therefore, the sensitivity suppression and the power ratio are estimated as follows:
[0095] (1) Estimation of Sensitivity Suppression of input Signal of Receiving Side
[0096] If expressing the sensitivity suppression ƒ due to nonlinear interference in dB and entering equation (2) into equation (4), the unmodulation wave (frequency f c1 ) component y Ic1 is expressed by the following equation (5):
y fc1 −a 1 V 1 ·cos (2 πf c1 t ) −a 3 V 1 3 /2 ·cos (2 πf c1 t ) −a 3 V 1 ·3/2 ·cos (2 πf c1 t ) xg ( t ) 2 (5)
[0097] If designating the power of the interfering wave side as P 2 , P 2 is expressed by the following equation (6):
P 2 = ∫ 0 T g ( t ) 2 × cos 2 ( 2 π f c2 t ) / ( T · R ) t ( 6 )
[0098] where, T is the integrated time interval, g(L) is expressed by equation (3), and, when V 2 =V 2 (k), P 2 =1/2 ·V 2 3 /2/R.
[0099] Here, R is the input impedance of the receiving side.
[0100] The relationship between the ratio a 3 /a 1 of the coefficients a 3 and a 1 in equation (4) and the input third-order intercept point IIP3 is known in advance and may be expressed as follows:
a 3 /a 1 =1/(3/2 ·R·IIP 3)
[0101] If designating the input impedance of the receiving side as R and normalizing the input powers V 1 and V 2 of the receiving side of the frequencies of f c1 and f c2 by the input third-order intercept point IIP3, the powers I 11 and I 12 become as follows:
I 11 =V 1 2 /2 /R /( IIP 3)
I 12 =1/2 ·V 2 2 /2 /R /( IIP 3)
[0102] The sensitivity suppression is expressed by the following equation (7):
[0103] η−20 ×log |1 −I I11 −2 ·I i2 | (7)
[0104] The sensitivity suppression η at the input signal of the receiving side for finding the nonlinear interference can be estimated based on the third-order input intercept point IIP3 found from the received power (received signal level) and nonlinear interference theoretical curve.
[0105] In place of the IIP3, it is also possible to use the third-order output intercept point OIP3. Further, if it is possible to find the coefficient ratio a 3 /a 1 by another technique, that may be used as well.
[0106] (2) Estimation of Power Ratio (C/I 3 ) Between Power C of Carrier f c1 at Output Signal of Receiving Side and Power of Nonlinear Third-Order Interference Wave Relating to That Carrier f c1 .
[0107] The double modulated wave component of the f c1 component of the output signal of the receiving side is expressed by the following equation (8) from the third term of equation (5):
y c1−IM =−a 3 V 1 ·3/2 ·cos (2π f c1 t ) xg ( t ) 2 (8)
[0108] If using the value T 12 obtained by normalizing the total power of the frequency f c2 by the input third-order intercept point IIP3, the power ratio (C/1 3 ) of the power C of the carrier f c1 at the output signal of the receiving side and the third-order power related to this carrier f c1 becomes the following equation (9):
C/I 3 =−10 log (lin a )+ A (9)
[0109] Here, A is a constant determined by the frequency spectrum distribution of the interference wave frequency f c2 , maximum modulation frequency, and equivalent reception band width (BW) of the frequency f c1 .
[0110] When the frequency spectrum distribution of the interference frequency f c2 is constant, if entering equation (3) for g(t) in equation (8) and finding the power, the power spectrum component (P c1-m ) of the interference wave output from the receiving side becomes the following equations (10) to (12):
P c1-m −( −a 3 3/2) 2 ·( P C1 )·(2 R·Pin/Fm ) 2 x|f m |/2) (10)
−Fm≦f
m
≦O|O≦f≦Fm
+( −a 3 3/2) 2 ·( P C1 )·(2 R·Pin/F m ) 2 x ( Fm−|f m |/2) (11)
+) −a 3 3/2) 3 x ( P C1 ) X (2 R×Pin/Fm ) 2 X ( Fm−|f m ) (12)
−F
m
≦f
m
<O|O≦f
m
≦Fm
[0111] If making the reception pass band BW of the interfered wave frequency f c1 much less than Fm, from the power spectrum P c1-m expressed by equation (10) to (12), the power (P BW ) of the interference wave in the range of f c1 −BW/2<f c1 +BW/2 is obtained by integrating equation (10) to equation (12).
[0112] Normalizing the powers of the frequencies f c1 and f C2 by the input third-order intercept point IIP3 and applying
a 3 /a 1 −1/(3/2 ·R·IIP 3)
I 12 =V 1 2 /2 /R /( IIP 3)
I 12 =1/2 ·V 2 2 /2 /R /( IIP 3)
[0113] to P BW , the power I 3 of the interference wave output from the receiving side is estimated by the following equation (13):
I 3 =2( −a 3 /IIP 3)·( P C1 )·(2 ·Pin/Fm) 2 x ( Fm×DW /2 −DW 2 /16) (13)
[0114] The ratio (C/I 3 ) of the power C, where C=(a 1 ×V 1 ) 2 /3/R), of the basic component of f C1 with I 3 expressed by equation (13) becomes:
C/I 3 =−10 ×log [8× Iin 2 ×{BW/Fm /2−( BW/Fm ) 3 /16}] (14)
[0115] The constant A of equation (9) is
−10 ×log [8× {BW/Fm /2−( BW/Fm ) 2 /16}] (15)
[0116] (3) Estimation of Error Rate Characteristic
[0117] a) QPSK Delay Detection Type Simplified Error Rate Characteristic is:
BER =1/2 ×exp (−/2) (16)
[0118] Here, if the signal to noise power ratio is ρ,
ρ=A 2 /2/50/σ 2 (17)
[0119] where, σ 2 : noise power, A: amplitude of carrier, 50 : impedance
[0120] If the reception power of the frequency f C1 is C and the sensitivity suppression is ηρ becomes the following equation (18):
ρ=1/ {1/(η·δ· C/P n )+1/(η·δ· C/I 3 )} (18)
[0121] where,
[0122] I ACP : leakage power affecting interfered wireless communication as calculated from interference wave power and reduction factor (IRF) (I IRF =IRF×power P 2 of interference wave side).
[0123] C/I 3 is the power ratio (truth value) of the f c1 component expressed by equation (15) and the intermodulation wave component relating to f c1 .
[0124] η is the sensitivity suppression (truth value) factor as calculated from equation (7).
[0125] δ is the fixed deterioration of the bit error rate arising due to imperfections in the transmitter/receiver (truth value).
[0126] b) QPSK Delay Detection Type Error Rate Characteristic
BER = Q ( a , b ) - 1 2 × exp [ - a 2 + b 2 2 ] I 0 ( ab )
{ a = 2 γ ( 1 - l / 2 ) b = 2 γ ( 1 + l / 2 ) ( 19 )
[0127] Q: Marcum O-function
[0128] I O : O-th modification Bessel function of the first kind
y =1/{1/(η·δ· E b /N o )+1/(η·δ· BN·E b /I ACP )+1/(η·δ· Bn·E b /I 3 )} (20)
[0129] where,
[0130] E b : energy per pit
[0131] N o : noise power density
[0132] I ACP : leakage power affecting interfered wireless communication as calculated from interference wave power and reduction factor (IRF) (I ACP =IRF×power P 3 of interference wave side)
Bn · E b / I 3 - C I 3 · Bn k · Bn · T ( 21 )
[0133] C/I 3 is the power ratio (truth value) of the f C1 component expressed by equation (14) and the intermodulation wave component relating to f C1 component.
[0134] Bn: reception equivalent noise band width of interfered wireless communication
[0135] T: time length with respect to symbol period
[0136] k: amount of information (bits) per symbol
[0137] η: sensitivity suppression (truth value) factor as calculated from equation (7)
[0138] δ is the fixed deterioration of the bit error rate arising due to imperfections of the transmitter/receiver (truth value)
[0139] c) QPSK Absolute Synchronous Detection Error Rate Characteristic
BER −1/2 ×erfc {square root}{square root over (y)} (22)
[0140] where,
y ={1/(η·δ· E b /N O )+1/(η·δ· Bn·E b /I ACP )+1(η·δ· Bn·E b /I 3 )} (23)
[0141] Here,
[0142] E b : energy per bit
[0143] N O : noise power density
[0144] I ACP : leakage power affecting interfered wireless communication as calculated from interference wave power and reduction factor (IRF) (I ACP =IRF×power P 2 of interference wave side)
Bn·E b /I 3 = b C · k Bn ·Bn·T (24)
[0145] C/I 3 is the power ratio (truth value) of the f C1 component expressed by equation (14) and the intermodulation wave component relating to f C1 component.
[0146] Bn: reception equivalent noise band width of interfered wireless communication
[0147] T: time length with respect to symbol period
[0148] k: amount of information (bits) per symbol
[0149] η: sensitivity suppression (truth value) factor as calculated from equation (7)
[0150] δ is the fixed deterioration of the bit error rate arising due to imperfections of the transmitter/receiver (truth value)
[0151] d) QPSK Differential Synchronous Detection Error Rate Characteristic
[0152] This is found as about double the QPSK absolute synchronous detection error rate characteristic.
BER=erfc {square root}{square root over (y)} (25)
[0153] Next, the increase in the adjacent leakage power due to the interference wave intermodulation product when the frequency interval of the interference wave and interfered wave is narrow in absolute terms will be explained.
[0154] As shown by the broken lines of FIG. 5B, when three times the modulation frequency of the modulated wave at the interfering side is broader than the frequency interval of the interference wave and interfered wave, the interference wave component causes the adjacent leakage power to increase due to the third order distortion of the wireless receiver of the interfered side.
[0155] If the ratio of the adjacent leakage power increasing by this intermodulation product with the power of the wireless band of the interference wave is designated as IRF 3 , it may be expressed as follows:
IRF 3 =−10 ×log[Iin 2 ]+B (26)
[0156] Here, B is a constant determined by the frequency spectrum distribution of the frequency f c2 , the maximum modulation frequency, the equivalent reception band width (BW) of the frequency f c1 , and the frequency interval between the frequency f c1 and the frequency f c2 .
[0157] When the frequency spectrum distribution of the interference frequency f c2 is constant, if entering equation (3) into equation (4), the component (Y) resulting from third-order distortion of the frequency f c2 component is
y=−a 3 ×g ( t ) 3 (27)
[0158] If entering equation (3) into equation (27), the frequency f c2 component is expressed as follows:
[0159] Here,
[0160] V 2 (k), k th modulation signal voltage of baseband of mobile wireless equipment at interfering side
[0161] Δf m : modulation frequency interval of baseband at interfering side
[0162] Δθ k : phase of k th modulation frequency of mobile wireless equipment of interfering side
[0163] Δθ 1 : phase of 1st modulation frequency of mobile wireless equipment of interfering side
[0164] Δθ m : phase of m-th modulation frequency of mobile wireless equipment of interfering side
[0165] Fm=n×Δf m : maximum modulation frequency of mobile wireless of interfering side
[0166] f C2 : carrier frequency of mobile wireless equipment of interfering side
[0167] θ(t): phase of carrier frequency of mobile wireless equipment of interfering side
[0168] [V]: range of product-sum
[0169] Expressing equation (28) by the A+B+C type, A+B−C type, A−B+C type, and A−B−C type by combination of the modulation frequencies, expressing the composite frequency of the three modulation waves of the K, l, and m components by L, expressing the composite frequency of the two modulated waves of the l and m components by S, and converting the modulation frequencies to L, S, and m in equation (28), the power with respect to f L =L·Δf m is expressed by the following:
P fc2 ( f L )= (29)
A+B+C TYPE
+3×( −a 3 ·3/4·2 R ) 2 ·2/3·( Pin/Fm) 3 ·1/12 · 1 L 2 (1)
Fm>f
L
≦O|O>f
L
≦Fm
[0170] Here, “|” expressess “or” of the left side condition and right side condition. Namely, the above expression means that −Fm<f L <O<f L <O or O<f L <Fm is satisfied.
+3×( −a 3 ·3/4·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/6·1/8·(3 Fm−|f 2 |) 2 2
2 Fm≦f L <Fm|Fm<f L ≦2 Fm
+3×( −a 3 ·6/8·2 R ) 3 ·2/4( Pin/Fm ) 3 ·1/16·( f L −Fm )·(7 Fm −3 f L ) -3
+3×(−=·6/8·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/3·1/16·(3 Fm−f L
−3 Fm≦f L <−2 Fm| 2 Fm<f L ≦3 Fm
+3×( −a 3 ·6/7·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/16·(3 Fm f L ) 2 -5
−3 Fm≦f L <−2 Fm |2 Fm<f L <3 Fm
A+B−C TYPE
+3×( −a 3 ·6/8·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/4( Fm−|f L |) 2 -6
−Fm≦f
L
<O|O<F
L
<Fm
+3×( −a 3 ·6/8·2 R ) 2 -7
f
L
=O
+3×( −a 3 ·6/8·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/4·( Fm−|f L |) 2 -8
−Fm<f
L
<O|O<f
L
<Fm
A−B+C TYPE
3×( −a 3 ·6/8·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·( Fm−|f L |)·|f L | -9
−Fm≦f
L
<O|O<F
L
≦Fm
A−B−C TYPE
+3×( −a 3 ·6/8·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/4·(2 Fm−|f L |) 2 -10
−2 Fm≦f L ≦−Fm| ( fm ) ≦f 2 ≦(2 Fm )
+( −a 3 ·6/8·2 R ) 2 ·2/4·( Pin/Fm ) 3 ·1/4 ·f L 2 -11
−Fm<f
L
<O|O<f
L
<Fm
[0171] Applying a 2 /a 1 =1/(3/2·IIP3·R) and making the reception pass band of the frequency f c1 BW<<Fm, if integrating the power (P BW ) in the range of the power P fc2 (f L ) to f c1 BW/2≦f m ≦f c1 +BW/2 by equation (29) and dividing the result by the total power of the wireless band of the frequency f c2 component to find IRF 3 , the following is obtained:
IRF 3 =10 ×log ( Iin 2 )+10 ×log (30)
+1/4×( f L 2 +( BW /2) 3 /Fm 2 )· BM/ 2 /Fm ) 1
O<f L <Fm−BW /2
+1/16×( BW /2 /Fm )·|( f L /Fm −1/3·( BW /2) 2 /Fm 3 ) -2
Fm+BW /2 <f L <2 Fm
+3/16( BW /2 /Fm )·{(7−3 f L /Fm )·( f L /Fm −1)·( BW /2) 3 /Fm 2 } -3
Fm+BW /2 ≦f L ≦2 Fm−BW /2
+1/16×( BW /2 /Fm )·{(3 −f L /Fm ) 2 +1/3·( BW /2) 2 /Fm 3 } -4
2 Fm+BW /2 <f L <3 Fm−BW /2
+3/16( BW /2 /Fm )·{(3 −f L /Fm ) 2 +1/3·( BW /2) 2 /Fm 2 ) -5
2 Fm+BW /2 <f L <3 Fm−BW /2
+1/24×[3−{ f l /Fm−BW /2 /Fm ) 2 ·( f L /Fm+BW /2 /Fm )·(−2( f l /Fm+BW /2 Fm ) 3 +9( f l /Fm+BW /2 /Fm )−9}]
Fm−BW /2 <f L <Fm+BW /2 -6
+{fraction (3/32)}×[( f L /Fm−BW 2 /Fm )·(( F L /Fm−BW /2 /Fm ) 2 −9( f L /Fm−BW /2 /Fm )+7)
2 Fm−BW 2/ <f L <2 Fm+BW 2/+( f L /Fm−BW /2 /Fm )·(1/3( f L /Fm+BW /2 /Fm ) 2 −3( f L /Fm+BW 2/ Fm )+9)−32/3] -7
+1/8×[ f L /Fm−BW /2 /Fm )·(( f L /Fm BW/ 2 /Fm )1/3( f L /Fm−BW /2 /Fm
+3/2×( BW /2 /Fm )·[(1 −f L /Fm ) 2 +( BW /2 /Fm )/3] -9
BW /2 <f L <Fm−BW /2
+3/2×[1/3·( BW /2 /Fm )·(3 /Fm+ ( BW /2 /Fm )−3( BW 2 /Fm ))+(( BW
+3× [f L /Fm ( BW /2 /Fm )·( f L /Fm ) 2 ( BW /2 /Fm ) 3 ] -12
BW /2 <f L <Fm L <BW /2
+3/2×( BW /2 /Fm )+( f L /Fm )−2/3( BW /2 /Fm ) 3 −2( BW /2 /Fm )
O>f L <BW /2
+3/2×(1/16−1/3)( f L /Fm−BW /2 /Fm )+1/3( F L /Fm−BW /2 /Fm ) 3 )
Fm−BW /2 <f L <Fm+BW /2
+3×(1/3( BW /2 /Fm ) 3 |( F L /Fm ) 2 ( BW /2 /Fm )) -15
O<f L <Fm−BW /2
+3/4((2 −f L /Fm ) 2 ( BW /2 /Fm )+1/3( BW /2 /Fm )) -16
Fm+BW /2 <f L <2 Fm−BW /2
+3/8×[2 ( f L /Fm BW /2 /Fm ) 3 /3+( f L /Fm+BW /2 /Fm )
Fm−BW 2 <f L <Fm+BW /2 [4−2( f L /fm+BW /2 /Fm )+( L /Fm+BW /2 /Fm ) 2 /3)] 17
+3/4×[4/3−( f L /Fm BW /2 /Fm )·(2−( f L /Fm−BW 2/ /Fm )+1/6( f L /Fm−BW /2 /Fm ) 2 )]-18
2 Fm−BW /2 <f L ≦2 Fm
[0172] Here, the frequency f C1 and f C2 are normalized by the input third-order intercept point IIP3 to obtain:
[0173] a 3 /a 1 =1/(3/2·R·IIP3)
[0174] I 11 −V 1 2 /2/R/(IIP3)
[0175] I 12 =1/2·V 2 2 /2/R/(IIP3 )
[0176] The dB value of equation (30) −1 to 18 is the constant B of equation (26).
[0177] The error rate characteristic is found by making the IRF, obtained by converting the IRP, (dB value) expressed by equation (30) to a truth value less than the leakage power value of equations (18), (20), and (23).
[0178] I ACP -(IRF|IRF 3 )×Power of Interfering Side P 2
[0179] Here, BW is the frequency band width of the interference signal, Fm is half of the maximum modulated wave frequency band width of the interference signal, and “|” means “or”.
[0180] The following action is obtained by the interference measurement and evaluation system according to the present invention explained in brief above:
[0181] It is possible to express the correspondence with the BER characteristic from the intercept point input level (IIP), reception thermal noise, and interference leakage power from an adjacent channel as a nonlinear characteristic of the interfered reception system using equations (7) and (14) expressing the signal of the desired wave input for reception of a modulated wave and signal of the interference wave by a discrete or continuous spectrum, equations (16) to (18) expressing the delay detection type simplified error rate characteristic, equations (19) to (21) expressing the QPSK delay detection type error rate characteristic, equations (22) to (25) expressing the QPSK absolute synchronous detection error rate characteristic, or double the bit error rate characteristic of equations (22) to (25) for the error rate characteristics of the QPSK differential synchronous detection error rate characteristic. Therefore, it is possible to enable estimation of the IIP3 of the reception as a whole and to more precisely and flexibly provide line qualities under nonlinear interference from the estimated IIP3.
[0182] [0182]FIG. 6 is a graph of an example of the bit error rate characteristic as an example of a line quality characteristic under nonlinear interference measured using the interference measurement and evaluation system shown in FIG. 1 as a test system. In FIG. 6, the curve A is the bit error rate characteristic when there is no interference, and the curves B to E show the bit error rate characteristic under nonlinear interference when gradually increasing and measuring the interference wave power. The points 61 to 64 are points of the received signal level versus bit error rate characteristic of the modulated wave signal when converting the ratio D/U of the power D of the desired wave (interfered side) and the power U of the interference wave to a constant one. The curve F shown the bit error rate characteristic under nonlinear interference when making constant the D/U estimated by connecting the points 61 and 64 .
[0183] To change the level of the received signal while making D/U constant, either only the transmitting side variable attenuator 13 is controlled or both the transmitting side variable attenuator 13 and interference side variable attenuator 16 are controlled. This control may be performed by the interference characteristic estimating means 20 or may be performed by other means.
[0184] In this embodiment, the points 61 and 62 are points where the bit error rate satisfies 1.3×10 −1 as an example. The bit error rate employed may be any error rate so long as it is in a region where the nonlinear interference is dominant. Note that the gradations 1.00E+00, 1.00E−01, 1.00E−2, . . . of the ordinate showing the bit error rate mean 1×10 0 , 1×10 −1 , 1×10 −2 . . . The lower in the figure, the lower the error rate. Further, the unit of the level of the normalized received signal of the abscissa is the decibel (dB). The further to the left in the figure, the lower the received level.
[0185] Here, the intercept point input level IIP3 of the receiving side as a whole in interfered wireless communication can be estimated from the following equation (32) from the normalized received signal level I 11 at 1.3×10 −2 as an example of the bit error rate at the received level region near the point 61 where the nonlinear interference is dominant and the measured value P C1 at the bit error rate 1.3×10 −2 .
IIP 3 −P r1 /I 11 (32)
[0186] However, the following conditions must be satisfied:
[0187] 1) The bit error rate 1.3×1- −2 near the line connecting the points 61 and 62 be a region where there is no effect from the received noise power, there is a level difference, and nonlinear interference is dominant.
[0188] 2) The bit error rate 1.3×10 −2 near the line connecting the points 61 and 62 be a region where there is no effect of the leakage power from the interference wave, the error rate of the curve B is sufficiently low, and nonlinear interference is dominant.
[0189] [0189]FIG. 7 is a block diagram of the configuration of an interference measurement and evaluation system according to a second embodiment of the present invention. In the figure, the difference from FIG. 1 is that the receiving side variable attenuator 21 is connected between the hybrid composition circuit 17 and the interfered digital wireless equipment 18 in the receiving means.
[0190] In this embodiment, by adjusting the receiving side variable attenuator 21 , the received level of the interfered digital wireless equipment 18 is controlled while making constant the ratio D/U of the modulated wave signal output input to the interfered digital wireless equipment 18 and the modulated carrier signal output from the interfering digital wireless equipment 15 .
[0191] [0191]FIG. 8 is a graph of an example of the bit error rate characteristic under nonlinear interference measured using the test system shown in FIG. 7. In the figure, the curve G shows the bit error rate characteristic when there is no interference, while the curve H shows the bit error rate characteristic under nonlinear interference. In this example, the points 81 and 82 on the curve H are points where the bit error rate is 1×10 −2 as an example.
[0192] Here, the intercept point input level IIP3 of the receiving side as a whole in interfered wireless communication can be estimated from the following equation (33) from the normalized received signal level I 11 at a bit error rate of 10 −2 as an example at the received level region where the nonlinear interference is dominant and the measured value P r1 at the bit error rate 10 −2 .
IIP 3 −P r1 /I 11 (33)
[0193] However, the following conditions must be satisfied:
[0194] 1) The bit error rate 10 −2 near the line connecting the points 81 and 82 be a region where there is no effect from the received noise power, there is a level difference, and nonlinear interference is dominant.
[0195] 2) The bit error rate 10 −2 near the line connecting the points 81 and 82 be a region where there is no effect of the leakage power from the interference wave, the error rate of the curve G is sufficiently low, and nonlinear interference is dominant.
[0196] Third Embodiment
[0197] In the present embodiment, the variable attenuator 13 and interfering modulated signal generator 14 shown in FIG. 1 or FIG. 7 are adjusted or the receiving side variable attenuator 21 is adjusted to lower the input level of the receiving means while maintaining the D/U constant so as to estimate the reception thermal noise characteristic.
[0198] [0198]FIG. 9 and FIG. 10 are views of the thermal noise characteristic under nonlinear interference measured using the interference wave power as a parameter. FIG. 9 and FIG. 10 are graphs substantially the same as FIG. 6 and FIG. 10, the received level is lowered and the receiver thermal noise is estimated from the received level of the region where thermal noise is dominant where an increase in the bit error rate due to the receiver thermal noise would become a problem.
[0199] Explaining this using FIG. 10 as an example, the measured reception thermal noise (Fn (unit: dB m )) is estimated as follows based on the normalized received level I 10 (dB) (not shown) determined from the received noise power, the level of the normalized received level I 11 (dB) determined under nonlinear interference at the point 82 where the line of the bit error rate 10 −2 of an example of the bit error rate at the received level region where the nonlinear interference is dominant intersects the curve H in the region of a low receiving level where the thermal noise would interfere with the inherent received signal, and the level difference showing the same bit error rate tested at a line quality test system:
P A −( I 11 +IIP 3)−Δ− D (34)
[0200] Here, Δ is the difference (Δ=P B −P A ) between the measured received level P A giving the bit error rate 10 −2 and the measured received level P A giving the bit error rate 10 −2 at the curve G when there is no interference, while D is the fixed deterioration showing the difference between the received level and theoretical value when the bit error rate characteristic 10 −2 at the curve G when there is no interference.
[0201] Fourth Embodiment
[0202] [0202]FIG. 11 is a block diagram of the configuration of an interference measurement and evaluation system according to a third embodiment of the present invention. In the figure, the difference from FIG. 7 is that a frequency conversion circuit 22 for changing the frequency of the interference wave is connected between the interfering digital wireless equipment 15 in the nonlinear interfering means and hybrid composition circuit 17 . This frequency conversion circuit 22 is comprised by a mixer circuit, a frequency shift local oscillator, a splice signal removing band pass filter, etc.
[0203] The frequency conversion circuit 22 can change the generated frequency of the frequency shift local oscillator.
[0204] In the present embodiment, the carrier frequency of the interference wave is changed so as to estimate the reception equivalent band limitation of the receiving side as a whole from the receiving side input level versus reception error rate characteristic of the modulated wave signal.
[0205] [0205]FIG. 12 is a graph of an example of the bit error rate characteristic under nonlinear interference measured using the interference measurement and evaluation system shown in FIG. 11. In the figure, curve I shows the bit error rate characteristic when there is no interference, curve J shows the bit error rate characteristic under nonlinear interference when the carrier frequency of the interfering digital wireless equipment, and the curve L shows the bit error rate characteristic under nonlinear interference when the carrier frequency of the interfering digital wireless equipment causes more attenuation at the initial band pass characteristic of the interfered digital wireless equipment.
[0206] The IIP3 of the receiving side of the interfered wireless communication device is found by the following equation (35) from the received level I 11 (1) at the bit error rate 10 −2 as an example of the bit error rate near the received level region where nonlinear interference is dominant when the carrier frequency of the interfering digital wireless equipment does not cause attenuation at the graph J showing the initial band pass characteristic of the interfered digital wireless equipment and the measured value P r1 of the power at the bit error rate 10 −2 .
IIP 3 =P r1 /I 11 (35)
[0207] However, the following conditions must be satisfied:
[0208] 1) The receiving region of a bit error rate of 10 −2 be a region where there is no effect from the received noise power, there is a level difference, and nonlinear interference is dominant.
[0209] 2) The receiving region of a bit error rate of 10 −2 be a region where there is no effect of the leakage power from the interference wave, the error rate of the curve J is sufficiently low, and nonlinear interference is dominant.
[0210] Regarding the attenuation with respect to the carrier frequency of any interfering digital wireless equipment, if the frequency interval between the center frequency of the interfered digital wireless equipment and center frequency of the interfering digital wireless equipment is made Δf(2) for the curve K and is made ΔI(3) for the curve L, the equivalent attenution at the initial band pass characteristic may be found from the following equations (36) and (37) from the normalized interfering levels I 11 (2) and I 11 (3) at the bit error rate 10 −2 :
L (2) =I 11 (1) −I 12 (2) (36)
L (3) =I 11 (1) −I 12 (3) (37)
[0211] Fifth Embodiment
[0212] In this embodiment, the interference measurement and evaluation system shown in FIG. 1 is used to estimate the reception equivalent leakage power which the interference wave of the receiving side as a whole has on the receiving side or interference reduction factor from the receiving side input level versus receiving error rate characteristic of the modulated carrier signal.
[0213] [0213]FIG. 13 is a graph expressing the equation of the bit error rate characteristic under nonlinear interference measured using the interference measurement and evaluation system shown in FIG. 1 by the D/U (truth value) and showing an example of the bit error rate characteristic under nonlinear interference. A curve substantially the same as FIG. 10 is drawn.
[0214] In FIG. 12, the curve G shows the bit error rate characteristic when there is no interference, while the curve H shows the bit error rate characteristic when the D/U under nonlinear interference is constant. The point 111 on the curve H is the point where the bit error rate characteristic shows the best value. The normalized received signal level is I 11 (4).
[0215] If setting
( D/U ) =I 11 /I 12 (38)
η=20 ×log |1 −I 11 −2 ·I 11 /( D/U )| (39)
[0216] Further
[0217] i C/I3−20 ×log | {1 −I 11 /( D/U )}/( D/U )}|−3 dB (40)
[0218] As an example, as a delay detection type simplified error rate characteristic,
BER −1/2 ×exp (−ρ/2) (41)
Ln (2× BER )=−ρ/2 (42)
[0219] Here, if the signal-to-noise power ratio is ρ, ρ become as in the following equation:
ρ=1/{1/(η·δ· C/P r1 )+1/(η·δ· C/I ACF )+1/(η·δ· C/I 3 )} (43)
[0220] Here, if the leakage power IACP is expressed by the ratio (IRF) between the leakage power of the interference wave and the initial band pass level of the adjacent interfered digital wireless equipment,
ρ=1/{1/(η·δ· C/P r1 )+1(η·δ· C/I ACP )+1/(η·δ· C/I best value of the bit error rate when making D/U constant is I 11 , using equation (38):
ρ=1/[1/(η·δ· C/P 11 )+1/{η·(δ· D/U )/IRF}+1/{η·δ· C/I 3 }] (45)
[0221] From equation (42) and equation (45),
−1/2 /Ln (2× BER )=1/(η·δ· C/P 11 )+1/{η·δ·( D/U )/ IRF} +1/{η·δ· C/I 3 }] (46)
[0222] From equation (46),
IRF={η·δ· ( D/U )×[−1/2 /Ln (2 ×BER )−1/(η·δ· C/P 11 )−1/{η·δ· C/I 3 }]} (47)
[0223] The leakage power ratio IRF is found using the above equations (38), (40), and (47) from the received signal level I 11 of the normalized interfered signal at the best value of the bit error rate when making D/U constant and the noise power (P 11 ) of the interfered digital wireless equipment.
[0224] Here, Ln( ) indicates the natural log (bottom “A”).
[0225] However, the point 111 showing the best bit error rate is the region where there is no effect from the nonlinear interference and received noise power on the curve H of the constant D/U ratio, there is a level difference, and the leakage power is dominant.
[0226] Sixth Embodiment
[0227] In this embodiment, an error rate characteristic test system for measuring the wireless communication line error rate under interference of the fifth embodiment is used to estimate the receiving side reception equivalent leakage power or interference reduction factor for the offset frequency of the interference wave and the interference wave.
[0228] [0228]FIG. 14 is a graph expressing the equation of the bit error rate characteristic under nonlinear interference measured using the test system shown in FIG. 7 by the D/U (truth value) and showing an example of the bit error rate characteristic under nonlinear interference corresponding to the frequency difference of the interference signal and interfered signal (offset frequency Δf 1 ).
[0229] [0229]FIG. 14, the curve M shows the bit error rate characteristic when there is no interference, while the curve N shows the bit error rate characteristic when the D/U under nonlinear interference is constant. The point 111 on the curve H is the point where the bit error rate characteristic shows the best value. The normalized received signal level is I 11 (4).
[0230] The normalized interfered wave received signal level of the best value of the bit error rate at the time of making the D/U constant for the offset frequency Δf 1 of the interference wave is I 11 (Δf 1 ) and the noise power of the interfered digital wireless equipment is (P N ), so F (Δf 1 ) is found from equation (47) using equations (38), (39) and (40). In this case, the effect of the leakage power is relatively small.
[0231] Further, the curve O in FIG. 14 shows the bit error rate characteristic under nonlinear interference when the offset frequency of the interference wave is Δf 2 smaller than Δf 1 . The point 142 is the point where the bit error rate characteristic in that case is the best value. The normalized received signal level is I 11 (2). The leakage power ratio IRF (Δf 2 ) becomes larger than IRF (Δf 1 ).
[0232] In this case as well, the leakage power ratio IRF (Δfp 2 )is found in the same way as above. IRF (Δf 2 ) becomes larger than IRF (ΔF 1 ).
[0233] Further, the curve P in FIG. 14 shows the bit error rate characteristic under nonlinear interference at the offset frequency Δf 3 smaller than Δf, of the interference wave. The point 143 is the point of the best value of the bit error rate characteristic. The normalized received signal level is I 11 (3).
[0234] In this case as well, the leakage power ratio IRF (Δf 3 ) is found in the same way as above. IRF (Δf 3 ) becomes larger than IRF (Δf 3 ).
[0235] However, the points 141 , 142 , and 143 showing the best bit error rate preferably are regions where the leakage power of a level difference of no effect from the nonlinear interference and received noise power on the curves N, O, and P where the D/U ratio is made constant is dominant.
[0236] Seventh Embodiment
[0237] In the present embodiment, in the same way as in the sixth embodiment, the reception equivalent leakage power of the receiving side is estimated for the offset frequency of the modulation wave signal and interference signal, but when the received signal level measurement is discrete, IIP3 and P N are given, but the receiving side input level versus received error rate characteristic for the D/U is only obtained discretely, but in this case as well, it is possible to approximate the input level at the best value of the receiving side input level versus reception error rate characteristic and estimate the reception equivalent leakage power or the interference reduction factor.
[0238] From equation (47),
−1/2/ Ln (2× BER )=1/(η·δ· C/P N )+1/{η·δ·( D/U ) /IRF} +1{η·δ ·C/I 3 } (48)
[0239] Here,
( D/U ) =I 11 /I 12 (49)
η=[1 I 11 2 ·I 11 /( D/U )] 2 (50)
C/I 3−1/2×[1− I 11 −2· I 11 3 /( D/U ) 2 ] 2 (51)
[0240] It designating the receiving side input level when measuring the bit error rate characteristic I 11 (1), I 11 (2), . . . I 11 (n) and the bit error rate at those times ber(1), ber(1), . . . ber(n) and using polynomial interpolation as an example of approximation,
BER ( r ) =ber( 1) ×L 1 ( r ) +ber (1) ×L 2 ( r )+. . . ber (1) ×L 3 (2) (52)
[0241] Here,
L i ( r ) = ( r - r 1 ) ⋯ ( r - r 1 - 1 ) ( r - r 1 - 1 ) ⋯ ( r - r n ) ( r 1 - r 1 ) ⋯ ( r i · r 1 - 1 ) ( r 1 r 1 - 1 ) ⋯ ( r 1 - r n ) r 1 = I i1 ( k )
[0242] If differentiating the bit error rate by “γ” when D/U is constant, the minimum value is
0 - r d [ ber ( 1 ) × L 1 ( r ) + ber ( 1 ) × L 2 ( x ) i ⋯ ber ( 1 ) × L n ( r ) ]
[0243] From the above, “γ” is found, BER(r) is found from equation (52), and IRF is found by entering equation (50) and equation (51) into equation (48).
[0244] The present embodiment can also be realized by the interference evaluation system shown in FIG. 11. In FIG. 11, the interference evaluating means 20 collects information from the variable attenuators 13 , 16 , and 21 and the frequency conversion circuit 22 , enters the bit error rate of the error rate measuring device 19 as data, and uses the algorithm shown in the present embodiment to specify the input level of the best value for the discrete offset frequency and estimate the reception equivalent leakage power or interference reduction factor.
[0245] Eighth Embodiment
[0246] In the present embodiment, it is made possible to estimate the line quality characteristics of a receiving means for the level or offset frequency of the interference signal of any signal using the nonlinear interference theoretical value or theoretical curve.
[0247] That is, a means is provided for enabling estimation of the nonlinear interference characteristic from the region where the nonlinear interference is dominant for any offset frequency, estimation of the reception thermal noise from the IIP3 as the reception performance and region where the reception thermal noise is dominant, estimation of the interference reduction factor of the interference signal from the reception thermal noise as the reception performance and the region where the adjacent power is dominant, and estimation of the bit error rate under nonlinear interference for any offset frequency signal and input power level of the interference signal from the known interference reduction factor using equations (7) and (14) and using equations (16) to (18) expressing the delay detection type simplified error rate, equations (19) and (20) expressing the QPSK delay detection type error rate, equations (22) and (23) expressing the QPSK absolute synchronous detection error rate, or double the bit error rate characteristic of equations (22) and (23) for the bit error rate characteristic of the QPSK differential synchronous detection error rate characteristic.
[0248] Ninth Embodiment
[0249] In the present embodiment, even if the measured values of the receiving side input level and reception line quality characteristic linked with the nonlinear interference theoretical curve are discrete, it is possible is estimate the nonlinear interference characteristic for any offset frequency, automatically estimate the adjacent leakage power etc., and estimate the line quality characteristic.
[0250] If the receiving side input level when measuring the bit error rate characteristic is C 1 , C 2 , . . . C 3 and the thermal noise of the reception system is P, the bit error rates at that time are ber 1 , ber 2 , . . .ber n , so using polynomial interpolation as an example of approximation:
BER ( r ) =ber 1 ×L 1 ( r )+. . . ber n ×L n ( r ) (53)
[0251] Here,
L i ( r ) = ( r - r 1 ) ⋯ ( r - r i - 1 ) ( r - r i - 1 ) ⋯ ( r - r n ) ( r i - r 1 ) ⋯ ( r i - r i - 1 ) ( r i - r i - 2 ) ⋯ ( r i - r n ) r 1 = C 1 / P n
[0252] In general, using equation (17) and equation (18),
ρ− A 2 /2/50/σ 2 (54)
[0253] : noise power
[0254] If the received power of the frequency f is C, the sensitivity suppression factor is η, and δ is the fixed parameter, ρ becomes the following equation:
ρ−1/{1/(η·δ· C/P N )+1/(η·δ· C/I ACP )+1/(η·δ· C/I 3)} (55)
[0255] 10th Embodiment
[0256] In this embodiment, the nonlinear interference characteristic of the receiving side as a whole is estimated based on the receiving side input level versus reception line quality characteristic of the modulated carrier signal and the received levels at the region where the adjacent power is dominant and the region where the received thermal noise is dominant.
[0257] [0257]FIG. 15 is a graph of the bit error rate characteristic under nonlinear interference in a 10th embodiment. In the figure, the curve Q shows the bit error rate characteristic when there is no interference, while the curve R shows the bit error rate characteristic when making the interference power larger. As shown in the figure, in this case, data is not obtained in the region where the interference power is dominant. In this embodiment, the nonlinear interference characteristic of this unknown region is estimated by the following technique.
[0258] From equation (56),
−1/2 /Ln (2 ×BER )=1/(η·δ· C/P n )+1/(η·δ·( D/U )/ IRF )+1/(η·δ· C/I 3 ) (56)
[0259] Here,
( D/U ) =T 12 /T 12 (57)
η=[1 −I 12 −2 ·I 11 /( D/U )] 2 (58)
C/I 3 =1/2×[1 −I 11 −2 ·T 11 2 /( D/U ) 2 ] 2 (59)
[0260] When D/U is constant and C/PN and D/U/IRF are known, equation (56) is found from equation (60)
−1/2/ Ln (2 ×BER )=1/η×σ x ( C/P )+1/(η×σ( D/U )/ IRF )+1
[0261] From the equation (60), equation (58), and equation (59), the reception signal level I 11 is determined.
[0262] If considering the fact that this is not a nonlinear region, η is set as “1” and equation (60) becomes as follows using equation (59):
C / I 3 = 1 - 1 2 · Ln ( 2 × BER ) - 1 ( δ · C / P n ) - 1 ( δ · D / U ) · IRF ( 61 ) 1 2 · [ 1 - T i1 - 2 · Ii 1 2 / ( b / V ) 2 ] 2 = 1 - 1 2 · Ln ( 2 × BER ) - 1 ( δ · C / P n ) - 1 ( δ · D / U ) · TRF ( 62 ) [ 1 - I i1 - 2 · I i1 2 / ( D / U ) 2 ] = - 2 1 2 · Ln ( 2 × BER ) - 1 ( δ · C / P n ) - 1 ( δ · D / U ) · IRF ( 63 ) I i1 = - 1 + 1 + 8 / ( D / U ) 2 × [ 1 - 2 - 1 2 · Ln ( 2 × BER ) - 1 ( δ · C / P N ) - 1 ( δ · D / U ) · IRF ] { 4 / ( D / U ) 2 } ( 64 )
[0263] If making the measured value Pr, IIP becomes IIP3=P/T
[0264] Summarizing the effects of the invention, as clear from the above explanation, according to the present invention, since an interference measurement and evaluation system using a nonlinear interference theoretical curve linked with a received line quality characteristic so as to estimate the reception characteristics under nonlinear interference, estimate the reception thermal noise characteristic, estimate the ratio between the third-order distortion coefficient a 3 and first-order distortion characteristic due to nonlinear interference or third-order intermodulation (IIP3), estimate the reception pass band characteristic, and estimate the leakage power from an adjacent channel is provided, it becomes possible to take measures against deterioration of the line quality due to nonlinear interference.
[0265] While the invention has been described with reference to specific embodiments chosen for purpose of illustration, it should be apparent that numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.
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An interference measurement and evaluation system for accurately estimating an interference characteristic of a receiving side including nonlinear interference for a wireless communications system, having a transmission signal for wireless communication and an interference signal between a transmitting means and receiving means, provided with a nonlinear interfering means for giving an interference signal having a level unable to be neglected compared with the level of the modulated carrier transmitted from the transmitting means, and provided with an interference characteristic estimating means for estimating an interference characteristic including a nonlinear interference characteristic possessed by a receiving means in accordance with a received signal level and a received level when a nonlinear interference theoretical curve given in relation with the line quality satisfies a predetermined line quality.
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BACKGROUND OF THE INVENTION
In the past, various types of metal detectors, magnets, microswitches and eddy current devices have been utilized to protect the carding machine from damage due to foreign objects being present in the lap being fed into the card. All of these devices have fallen far short of desired goals, and the use of some of the devices installed at or under the feed roll of the card have resulted in more costly damage than they prevent. Other devices will only detect metal and will not detect nonferrous metals or other hard materials capable of damaging the card. Such materials include glass, rock, wood, plastics, leather and the like. Damage from such foreign objects can necessitate costly repairs or rebuilding of the card, as is well known.
The object of this invention, therefore, is to provide a foreign object detector which can detect minute objects having a thickness of as little as 0.001 inch with a lateral dimension of about 3/32 inch, regardless of the material the hard object is made of. Furthermore, the mechanical detector can act twice or more on every advancing region of the lap before the lap enters the feed roll. Individual foreign object feeler pins compactly arranged in staggered relationship in multiple rows assure that no foreign objects in the lap will escape detection. When such an object, or objects are detected by the mechanism, the doffer and feed roll will be stopped automatically and cannot be restarted by the operator until the foreign object is removed from the lap, thus assuring complete protection of the card. An indicator is included in the device to alert the operator to the presence of foreign objects and a convenient viewing panel is provided through which the operator can directly observe which feeler pin have been elevated by contact with a foreign object.
The operational capability of the invention in protecting the card is far in excess of any known prior art system.
Other features and advantages of the invention will become apparent during the course of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic side elevation of a card equipped with a foreign object detector in accordance with the invention.
FIG. 2 is a fragmentary transverse vertical section through the mechanical detector device taken on line 2--2 of FIG. 1.
FIG. 3 is a vertical section taken on line 3--3 of FIG. 2.
FIG. 4 is a similar section taken on line 4--4 of FIG. 2.
FIG. 5 is a similar section taken on line 5--5 of FIG. 2 and showing an uncompressed lap passing through the detector mechanism.
FIG. 6 is a fragmentary horizontal section taken on line 6--6 of FIG. 2.
FIG. 7 is a view similar to FIG. 5 showing the lap compressed during operation of the detector mechanism.
FIG. 8 is a similar view showing the feeler or detector pins penetrating the lap with at least one such pin contacting a foreign object and being elevated thereby.
FIG. 9 is a fragmentary schematic view of a control circuit.
DETAILED DESCRIPTION
Referring to the drawings in detail and referring first to FIG. 1, a conventional revolving-top flat card 20 is shown having a feed roll 21, lickerin 22, card cylinder 23 and doffer 24. The foreign object detector 25 forming the subject matter of the invention is positioned in FIG. 1 just upstream from the feed roll 21 to protect the feed roll, the lickerin and the entire card from foreign object damage which would occur with costly results if an effective detector means were not present. FIG. 1 also shows the coiled lap 26 and lap roll 27 ahead of the detector 25. While a lap feeding card has been illustrated, the invention is also applicable to chute feed cards merely by altering the mode of operation of two pneumatic cylinders which coordinate the operation of the detector with the operation of the card, as will be further discussed.
Continuing to refer to the drawings, the detector apparatus 25 comprises bottom spaced mounting blocks 28 which rest on a solid support surface. The spacing of these blocks is sufficient to accommodate the full width of the lap 26 which measures about 40 inches on a standard size card. Such lap, before compression, FIG. 5, is about 3 inches thick and when compressed in the detector apparatus, FIG. 7, is about 1 inch thick. The blocks 28 support vertical guide posts 29 arranged in fore and aft parallel pairs, FIG. 3, in turn supporting a top plate 30 at their upper ends to which are suitably attached two vertical axis pneumatic cylinders 31 having depending piston rods 32.
The piston rods 32 are suitably secured to a feeler pin carriage bar 33 having guide bushings 34 therein which slidably engage the parallel posts 29. The carriage bar has a top opening cavity 35 formed therein providing a relatively thin bottom wall portion 36 on the carriage bar having plural rows of parallel equidistantly spaced apertures 37 formed therethrough across the full width of the cavity 35. As shown in FIGS. 7 and 8, preferably five equidistantly spaced parallel rows of the apertures 37 are provided in the wall portion 36 and the apertures of adjacent parallel rows are staggered laterally relative to each other, as shown in FIG. 6, to provide a rather high density of apertures and of the feeler pins 38 which are slidably mounted therein on parallel vertical axes.
The feeler pins 38 have heads 39 adapted to rest on the upper surface of plate portion 36 under influence of downwardly biasing springs 40 which surround reduced upper stems 41 of the feeler pins 38 and engage slidably through apertures 42 of a spring tension plate 43 suitably fixed in the cavity 35 above and parallel to the wall portion 36.
A lap compression plate and feeler pin cleaner 44 disposed substantially below the feeler pin carriage bar 33 in parallel relation thereto is supported by two pairs of parallel rods 45 near opposite ends thereof, such rods extending upwardly through guide bushings 46 fixed within openings of the carriage bar 33. The lap compression plate 44 is biased donwardly by lap compression springs 47 which surround the rods 45 and have their lower ends bearing on the plate 44 and their upper ends engaging the bushings 46 within spring receptor cavities 48 of carriage bar 33.
The top of cavity 35 is covered by a transparent cover plate 49 which enables the operator to have a clear view of the tops of the detector or feeler pins so that he can determine exactly where a detected foreign object 50 or objects, in the lap 26, is located, FIG. 8.
Below the lap compression plate and feeler pin cleaner 44 in parallel relationship thereto is a stationary ramp plate 51 over which the lap 26 passes, as shown in the drawings. This ramp plate has rows of apertures 52 formed therethrough which are coaxially aligned with apertures 53 of the lap compression plate and with the pointed pins 38. The ramp plate 51 is attached fixedly to the support surface on which the blocks 28 are based.
The apparatus further comprises an electrical grounding wire 54 lying in a horizontal plane near and above the tops of feeler pin extensions 41, FIG. 2. This wire is laced back and forth between two lacing bars 55 formed of electrical insulating material held in grooves 56 provided in the carriage bar 33. The continuous wire 54 is bodily supported on the insulating bars 55 and thus electrically isolated from the metal carriage bar 33. It comprises spaced parallel branches 57 with one such branch extending directly above and along each row of the feeler pin extensions 41. Hence, whenever one or more of the pins 38 in any row of pins rises due to contact with a foreign object 50, FIG. 8, the extension 41 or extensions will engage one of the strands or branches 57 of grounding stop motion wire 54.
As shown schematically in FIG. 9, the wire 54 is connected with a suitable circuit interrupter 58 forming a component of a conventional stop motion circuit 59. Whenever contact between the wire 54 and one or more of the pin extensions 51 occurs, the stop motion circuit will be broken and the operation of the card feed roll 21 and doffer 24 will be stopped. When stopped, the operator can observe through the transparent plate 49 which feeler pin or pins are elevated due to contact with an object 50 and the operator will then manually handle the lap 26 and remove the foreign object before restarting the card by utilizing a preferably key-operated reset switch in the stop motion circuit.
The exact configuration of the circuitry can vary considerably within the state of the art, and the details of circuitry are believed to be unimportant and unnecessary to disclose for a proper understanding of this invention. For example, the circuit may include an indicator light bulb and/or an audible signal to alert the operator to the detection of foreign objects. It may also include a burned out light bulb sensor and other state of the art components.
In the case of a lap feeding card 20, as shown in FIG. 1, the pneumatic cylinders 31 are single reverse-acting gravity extending cylinders. When the invention is applied to a chute feed card, the two cylinders are of the double-acting type. State of the art controls for the cylinders 31, not shown, synchronize their operation with the operation of the card. Preferably, the feeler pin carriage bar 33 reciprocates two or more times to push the pins 38 through the lap at each area of the lap spanned by the detector mechanism. Each penetration of the lap and compression thereof by the plate 44 is momentary, for about 1/10 of a second. The lap has its fibers loosely arranged and is slowly moving and therefore the repeated penetrations of the lap by the feeler pins does not effect the lap movement or the normal operation of the card.
Each time the carriage bar 33 descends, the compression plate 44 will compress the lap 26 to a thickness of approximately 1 inch and the springs 47 will yield to prevent further compression. The multiple pins 38 will now penetrate entirely through the lap and will enter the apertures 52 of the fixed ramp plate 51, as shown in FIG. 8. This assures detection of any foreign object at the very bottom of the lap. On the rise of the carriage bar 33 as pins 38 leave the top of the lap, they are stripped clean by the apertures 53 while the compression plate 44 is held down by the springs 47, following which the plate 44 will rise with the bar 33 and the parts ultimately return to their relative positions shown in FIGS. 2 and 5.
The apertures 52 of ramp plate 51 are sized to prevent passage therethrough of the smallest foreign objects 50 which are necessary to detect, namely, objects having a width measurement horizontally of about 3/32 inch. As shown in FIG. 5, the apertures 52 will also center and stabilize objects 50 on the ramp plate so that they will not escape detection by the feeler pins. The arrangement is such that the device is capable of detecting almost all potentially damaging foreign objects in the lap to protect the card and without interfering with its normal operation.
Other state of the art features not shown can and are preferably included in the device. Such features include a flow control valve in the pneumatic circuit of cylinders 31 to regulate the gravitational fall of carriage bar 33 when one-way pneumatic cylinders are employed with lap feed cards. A manual two position valve can also be provided to enable the operator to manually raise the carriage bar in preparation for removing foreign objects by hand from the lap after they have been detected.
The numerous advantages of the invention over the prior art should be readily apparent to those skilled in the art.
It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.
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A mechanical foreign object detector upstream from the feed roll of a carding machine faithfully detects minute hard objects in the lap which could damage the lickerin or other components of the card. Spring-loaded detector pins penetrate through the lap and contact foreign objects on an apertured plate beneath the lap. Such pins rise and contact a wire connected in a stop motion circuit which immediately stops the operation of the doffer and the feed roll before any damage can occur. A visual and/or audible indicator alerts the operator to the presence of a foreign object or objects which the operator removes by hand before restarting the card by operation of a key-operated reset switch in the circuit. The mechanical detector apparatus includes a power drive which is synchronized with the operation of the feed roll of the card.
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BACKGROUND OF INVENTION
[0001] This application is a divisional application of U.S. Ser. No. 10/063,427, filed Apr. 23, 2002, the disclosures of which are incorporated by reference herein in their entirety.
[0002] This invention describes a system and method for locating and defining process sensitive sites isolated to specific geometries or shape configurations within the chip design data, also leveraging the knowledge of the process sensitive sites found. Process sensitive sites are defined as those areas where the design assumptions and expectations have exceeded the actual process capability.
[0003] Electrical shorts and opens parameters are impacted where the process tolerance is not design compatible. This systematic yield loss may be driven by RIE loading effects, lithographic offsets, over/under layout sensitivities, topography, pattern density, and other adjacency effects, at specific process sensitive sites. Given the compression of the yielding production ramp-up cycle, design revisions with work in progress turns are no longer an option.
[0004] Fabricators and designers commonly use tools or systems for placing shapes to improve layout sensitivity and optimize for random defect tolerance. For example, wiring layout tools will not only optimize routing for timing and reduced delay, but also to modulate defect tolerance. The defect tolerance may be analyzed by critical area versus defect size computation or optionally analyzed by the distance and run length between conductive wires susceptible to random particles. Fabricators also use tools and systems for design rule and shapes checking. Another standard methodology to compute random photo yield includes throwing random defects at-level, generating faults at the random defect sites, then selecting the faults with shape checking programs. Yield is a function of the number of faults and the size distribution.
[0005] Systematic process defects are modulated with the use of automated tools or systems to place dummy shapes or slots, place additional redundant vias or contacts or other redundant elements, and to perform layout modifications for lithographic proximity corrections, and for other RIE and lithographic effects. In the semiconductor industry, these design-for-manufacturing activities are paired with other product or design complexity analyses such as total length of routed wires, and single via count data, for example.
[0006] Computer aided design analysis tools are also utilized in industry and integrated with manufacturing and test simulators such that circuit designers can understand the impact of design issues on manufacturability of test processing.
[0007] However, the inventors are not aware any tools or systems looking for sensitivities related to structures or process and layout incompatibilities, and leveraging that information as feedforward to the designer, as well as leveraging that information in manufacturing process controls methodologies, as is described above.
SUMMARY OF INVENTION
[0008] Therefore, a goal of this physical design characterization system is to improve the technology product development and the probability of first time fabrication success for new products and partnumbers. Once a systematic process sensitive site is identified, 3D design checking decks are coded and executed on the physical design data.
[0009] Checking deck jobs are triggered and processed for each new chip design when it is introduced into the fabricator.
[0010] Specific geometries and configurations in areas of known or potential layout sensitivities are identified as chip coordinates to the process owner and design team. Pictures of partnumber specific process sensitive sites are captured along with dimensional layout description and sent to a web site library for easy reference and analysis.
[0011] This physical design challenges for new partnumbers, the reference tool may be used to provide solution insights, it may be used to update tactical projections and floor plans, and the reference retains technology learning which can be reapplied to next technologies. It can also be used to improve design for manufacturing compliance, and used for resource management or prioritization correlated to difficult design partnumbers or sectors.
[0012] All the above results in improved serviceability, avoidance of production stoppage and scrap, and measurable time-to-profit achievements.
BRIEF DESCRIPTION OF DRAWINGS
[0013] [0013]FIG. 1 illustrates in a graphical form the differences between technology defined process windows and actual production process windows.
[0014] [0014]FIG. 2 illustrates in block diagram form how this characterization system and method works in a semiconductor development and manufacturing environment.
[0015] [0015]FIG. 3 illustrates in a graphical form the system architecture for the physical design characterization system of this invention.
[0016] [0016]FIG. 4 illustrates in block diagram form the conversion process that provides data that is visible to personnel and useful to processing and analysis equipment.
[0017] [0017]FIG. 5 illustrates a textual example of what appears in the contents table of this invention.
[0018] [0018]FIG. 6 illustrates in a graphical form an example of what appears on the chip map reference page of this invention.
[0019] [0019]FIG. 7 illustrates a textual example of what appears on the target summary page of this invention.
[0020] [0020]FIG. 8 illustrates in graphical form an example of what appears on the chip origin page of this invention.
[0021] [0021]FIG. 9 illustrates in a graphical form an example of the what appear on the process sensitive geometry page of this invention.
[0022] [0022]FIG. 10 describes in block diagram form the manufacturing tactical steps utilizing Fingerpt output.
DETAILED DESCRIPTION
[0023] As illustrated in FIG. 1, the genesis of each new technology node includes forming process and groundrule assumptions that will meet aggressive design configurations, competitive benchmarks, technology pitch, and feature portfolios. As illustrated, the process window changes as these original assumptions are turned into expectations and are further modified to the reality of the manufacturing floor. Further down the cycle toward manufacturability, technology engineers define the limits of the many process windows in chip fabrication, such as process tolerance, topography, reticle aberrations, tooling limitations, etc. Those limits are then converted into groundrule expectations and definitions through experience, technology qualification results, and/or anecdotal results. A process sensitive sites locator, as part of design content analysis system, allows the manufacturer to assess each design against the actual process capability, i.e., the reality in manufacturing, and to generate a unique control specification based on the design's content.
[0024] As shown in FIG. 2 a system also provides a feedback and strategic solution path to both technology development and design. This general methodology could be further extended to describe other physical design characterization (PDC) systems, in addition to the process sensitive sites locator described by this invention.
[0025] The primary goal of process sensitive sites locator is to locate design-process sensitive regions. One example of a process sensitive site is minimum pitch wires lying above wide metal wires, the latter separated by a narrow insulator (trench). Topographies induced within the integration may lead to electrical shorts at subsequent wiring levels. This is shown in block 20 of FIG. 2. In block 21 the invention translates the structural criteria into shape code. At block 22 the locator is deployed automatically when new part numbers are generated. At block 23 the locator runs and creates an output that can be used for characterization. At block 24 engineering assesses the impact of the results of block 23 and problems are identified. At block 25 the impact and problems are communicated to other engineering and development organizations. At block 26 the strategic solutions appropriated for the problems are chosen. At block 27 appropriate outcomes are provided to customers and fabricator personnel. Depending on the outcome a change in the criteria for the process sensitive sites locator is determined. As an alternative, the impact can be directly communicated to manufacturing through tactical solution (block 28 ) and then depending the solution the locator criteria are changed.
[0026] The system architecture for this process sensitive sites locator is described in reference FIG. 3. This architecture provides for the methodogy described in blocks 21 through 23 of FIG. 2. The system provides a fabricator with the opportunity to find a menu of process sensitive sites in an automated manner before or when new partnumbers enter the fabricator, scan the portfolio of released partnumbers for a (recently) defined process sensitive sites, or analyze a specific partnumber in search for new process sensitive “swamp” site. To process the structures described in block 20 of FIG. 2, one needs to pull in the specific data into a queuing system. The queuing system of block 30 , FIG. 3, allows for the interrogation of prerelease or release environment, which contains a record of chips, chip sizes, layers and design levels, partnumbers, and other pertinent information. Since these types of jobs are a good match for a distributed computing environment, a job scheduler (LoadLeveler, an IBM product, was used in the inventor's embodiment) is used to dispatch the job streams. Physical design data is transferred from the release environment of block 31 , checked for validity and proper levels in block 32 and then prepped if necessary. The next step is to perform the desired 3D design check in block 35 in a computer runtime environment suitable for handling large data loads and design checking software. The 3D design checker is comprised of one or more checks from an optimized code library. The 3D design checker will be further described below. These checks correspond to specific physical design characteristics or regions that may cause productivity loss. This is shown in FIG. 3 as elements 33 and 34 . The output of the design checker is the process sensitive sites target matches of block 36 , collected as target match shapes or vectors inserted into the original data. This data is then processed by extraction of physical design data in a graphics processing system 37 (“FingerPt” shown in block 37 will be discussed below), which produces pictures and maps of the target matches in block 38 . This visualization technique is organized into the web site of block 39 accessible by fabricator, development, and design personnel, along with site coordinates for auto loading into inspection tools or deployment for physical analysis.
[0027] The data and programs discussed above are stored in a variety of memory storage devices containing well-know media (disks, tapes, RAM, ROM, etc.) which are parts of the components of the system of FIG. 3 provided above.
[0028] Process sensitive sites target matching is dependent upon a clear definition, translated into design rule checks, of what the process sensitive sites are (FIG. 2, block 21 ). As an example of such definitions, the metal wiring levels may include the following structures:
[0029] 1. Min Spaced Via Farms on Different Nets=X×N arrays of vias that are min space. Line ends, passing wires, or electrical nets may also be described. Light interference, tool tolerance, etc, may cause these vias to print large.
[0030] 2. Min Pitch Metal over Wide Metal Regions=next level metal passing over a metal line of X×N minimum width may lead to electrical shorts from process induced topography. Other criteria could include isolating the search to regions where the local pattern density reaches a specified criterion, and searching for min width adjacent wiring.
[0031] 3. From the earlier example: Min Pitch Metal over Insulator Trenches=similar to #2, but wires passing over insulator regions immediately adjacent to or between large metal lines. These areas may lead to shorts at the next wiring level.
[0032] These definitions are then applied to a 3-D Design Checker 35 through the Design Check Library 34 . Looking for minimum pitch metal over insulator “trenches” entails a specific 3D design check comprised of calls to a source library containing frequently used base functions. These base functions are coded using an industry available non interactive design checking tool such as “Hercules” from Avant!, “Caliber” from Mentor Graphics, or the “Niagara” EDA tool from IBM and described by the following pseudo-code:
[0033] First: Wide Underlying Metal/Insulator
[0034] a) Take as input the lower metal level of interest. Also take as input a wide metal dimensional criteria, and wiring separation dimensional criteria.
[0035] b) Keep only the metal meeting the minimal wide metal dimensional criteria.
[0036] c) Generate corresponding insulator regions.
[0037] d) Keep only the insulator regions meeting the minimal insulator dimensional criteria.
[0038] e) Return the results of b) and d).
[0039] Then: Target Match/Region Determination
[0040] a) Take as input a 3D check (i.e. space, width, or some other characteristic, along with dependencies, filters, etc), input, and criteria.
[0041] b) Determine a single target match collected as a vector or shape (region) for each set of shapes not meeting the checking requirement.
[0042] c) Attribute these shapes with check and level information to be passed to the physical design visualization program (described later).
[0043] Illustrating further, an example of a design check utilizing some of the above base functions, is described by the following pseudo-code: Metal shorts due to induced topography:
[0044] a) Take as input the metal layer experiencing shorts and the layer below. Also take the minimum space and width criteria for the upper metal, and the wide metal dimensional criteria described in base function “wide underlying metal/insulator”.
[0045] b) Determine where the wide lower metal is by using the base function “wide underlying metal/insulator”.
[0046] c) Determine which upper metal is at minimum pitch.
[0047] d) Identify the minimum pitch regions found in c) that intersect with the wide lower metal found in b).
[0048] e) Use d) and the base function “target match/region determination” to find the target matches.
[0049] f) Add these collected matches or shapes to the original design for later use during extraction of the PD data.
[0050] The process sensitive sites locator organizes and presents the resulting data after identifying the target matches associated with a particular 3D design checker. The resulting data are in a format that the engineer can easily understand, make use of, and visualize through the use of physical design extraction data. The data are output to a Web site and contain a summary and details of the findings for each process sensitive sites. A high level illustration of how process sensitive sites locator information is communicated and used is shown in FIG. 4.
[0051] The organizational phase of the output, named FingerPt, consists of collecting and sorting the target matches by type (there may be multiple types of targets for a single design check run). This shown as block 40 on FIG. 4. Because there may be thousands of sensitive sites, the data are sampled in block 41 in order to reduce data volume while maintaining a representative group of matches, and extracting information about the individual matches(e.g., geometric and attribute data). The presentation phase consists of creating a series of “views” as shown in blocks 42 a, b, c and d of the data shipped to a web site containing textual and graphical pages (in GIF format).
[0052] This information is then converted in block 43 to data recognizable by analysis and processing equipment shown as 44 a, b, c and d.
[0053] The data is presented on a website. The website contains a contents table which consists of a selection of “hot links” to the other outputs from the data extracted through FingerPt . The information that is provided includes a chip map reference, a data summary, and a series of origin and geometry output pages. The series of graphical pages occur for each target match of the particular type of target.
[0054] “Min Pitch Metal over Insulator Trenches” is an example of one type of target. The Contents Table, for the example shown in FIG. 5, includes a unique integer to identify the target match kept in the sample, an X-Y coordinate pair for the match, and additional information specific to the process sensitive sites match (generated in the design check run).
[0055] The chip map page, an example of which is FIG. 6, consists of X-Y locations of the target matches in an overall view within the chip or circuit, and are indicated by unique integers corresponding to the graphical pages.
[0056] The summary page, an example which is FIG. 7, consists of a list of the target types, and the total number of matches of each type in the design check data file before data reduction.
[0057] There is a chip origin reference, an example of which is FIG. 8, provided for each target type in the output file. The chip origin reference provides a visual confirmation with regard to the geometry pages to compare with on-wafer origin, and in the preferred embodiment they consist of views of the extreme lower left section of the geometry, showing data levels relevant to the particular target type.
[0058] The individual geometry pages, an example of which is shown in FIG. 9, give a graphical representation, using GL 1 in the preferred embodiment, of the shapes that are relevant to a particular target match. Irrelevant data levels are suppressed in order to improve clarity. X and Y axes include data scales, and a legend identifies data levels by color, line style, and fill style. One of these levels contains the target marker information, shown as the specific location of the target match, generated by the design data check for the particular target match.
[0059] The following pseudo-code describes how it works:
[0060] 1. Take as input parameters: the PD data file, X-Y coordinate file, HTML/GIF output directory, target matches, window margin, view set (colors, fill patterns, etc.), and window limit.
[0061] 2. Read the model data from the PD data file.
[0062] 3. Create an internal list of target match windows:
[0063] 3A. If writing windows by shape:
[0064] a) Hierarchically traverse all shapes on the match level, building a list of match types, determining pertinent data levels, and counting target match shapes by type.
[0065] b) Traverse the match shapes again, using the information previously gathered to build a list of windows by selecting the Nth shape of each match type, where “N” is determined by the window limit and the number of target match shapes of that type. This method of sampling helps avoid clustering of windows.
[0066] c) Sort the window list by match type.
[0067] 3B. If writing windows by X-Y coordinates:
[0068] a) Traverse the coordinate file, building a window list by adding a window for each coordinate location.
[0069] 4. Create a GIF file in the HTML directory containing a graphical map of the selected target match locations.
[0070] 5. Create a summary HTML file, listing the total number of matches for each error type.
[0071] 6. Create an HTML index file, to be filled in with a selectable line for each GIF file written.
[0072] 7. Create a series of GIF files, one for each window in the list generated in step 3 :
[0073] For each window in the list:
[0074] a) If it is the first tgt match of its type, create a GIF file of the extreme lower-left corner of the input model, showing the data levels pertinent to the given match type.
[0075] This is to aid the reviewer in determining the orientation of the data.
[0076] b) Create a GIF file of the data model within the window, showing the data levels pertinent to the match type, and including a legend defining the data levels.
[0077] c) Add a selectable line to the index file for the window, giving the match number, match type, and X-Y coordinates of the target match.
[0078] [0078]FIG. 10 describes the manufacturing tactical steps utilizing the Fingerpt output described above. In the preferred embodiment, the process sensitive sites locator is triggered in an automatic execution of the 3D design rule check job, shown in block 50 , and is driven by a traceable design release process. The locator provides knowledge of designs coming into the fabricator such that proactive measures can be taken for learning and controls methodologies. The process sensitive sites locator output, ported to a Web application database, is reviewed by the engineering team to determine ease vs risk of manufacture and manufacturing readiness, shown in 51 a . The goal is to determine if all projected and known critical layouts have been exercised and shown to be contained within the process window tolerances allowed in the specifications. The assessment, used to accomplish this goal, includes but is not limited to a comparison of yield loss paretos to process sensitive site findings in type and count.
[0079] The assessment becomes crucial with the reduction of pitch and critical dimension driven by advanced technologies. Advanced technology assumptions and expectations are shown in block 51 b , where the process tolerance can consume the full breadth of the process window leaving little to no margin for design sensitivities. Engineering requests for process sensitive site locator may also be defined and run for the purpose of analyzing development testsites.
[0080] The use of the process sensitive sites locator to determine systematic losses from layout sensitivities, shown in block 52 , is implemented in concert with an existing process used for random defect learning and controls. The implementation decisions may include but are not limited to sample plan and personnel resource. The sample plan, in block 53 , includes representation by technology, product volume, process integration, layers, tool capacity, metric selection, and metrology tool type. By using specific locator coordinates, first-to-fail, process window corners, and health-of-the-line metrics are selected within the sample plan. High resolutions are gained because defect scanning inspections are not needed. Extent of the process sensitive sites or other layout attributes are also considered. In the preferred embodiment, process sensitive sites are ported to the metrology and inspection equipment, block 54 . Process recipes from historic sensitive site evidence are also selected and downloaded.
[0081] In the preferred embodiment, database connectivity provides for statistical limits charting from in-line systematic limited yield results (inspection and metrology results) as described in block 55 . The embodiment includes an automatic tool shutdown based on a shift seen in systematic limited yield metrics. From these results, characterization analysis of yield impacts, manufacturing engineering analysis for tool and process trends, feed forward to the design and development community, as well as feedback to customers is achieved.
[0082] An additional benefit that stems from the use of process sensitive sites and downloaded coordinates is the shortened time it takes to detect a shift in the fabricator. Historically, limited yield analysis, process learning, and technology qualification generally entail electrical review of kerf monitors, random defect scans and classification, along with wafer final test; product disposition limits are put on defectivity and electrical parameters for quality containment; fail samples are chosen for physical analysis. The mean-time-to-detect in this historical methodology can be extensive and can miss the systematic failure cause and effect. The process sensitive sites locator provides coordinates for hard to find sites, especially useful when the layout includes a small number of sensitive site occurrences within the chip data. The result is earlier detection, analysis, and disposition of systematic yield limiters within the release cycle of new partnumbers, block 56 . Existing focus teams, in daily and weekly forums, review tool trends and yield parameters, and systematic losses, blocks 57 and 58 .
[0083] In the case of the process sensitive site described earlier, minimum pitch metal over insulator trenches, the fail mechanism was not well understood and the layout sensitivity had not been previously exercised on incoming designs, block 51 a . Upon detecting the systematic fail site, a dimensional assessment and tolerance latitude were determined by engineering; manufacturing was engaged in the controls methodologies selected, blocks 52 and 53 . 3D design checking was initiated with the process sensitive site location coordinates downloaded to control tools, block 54 . Control limits were established for the in-line inspection metric, block 55 . Rework plans were established as part of disposition and tactical actions, block 56 . Results of the controls methodologies, as tool and yield trends were monitored and reviewed for manufacturing stability, block 57 . Improvements to the process integration were evaluated and qualified, block 58 .
[0084] From lessons learned on process sensitive site locations, other partnumbers and customer design style comparisons are initiated. Tactical and strategic solutions are determined from these physical design characterization results. The solutions may include, but are not limited to, generation of automated design tools to modify the sensitive structure into a process compatible layout, generation of measurement sites to develop new controls methodologies, development of processes or process adjustments to offer larger process window, redesign of existing partnumbers based on degree of problem and serviceability, and lastly, changes to groundrules and checking deck to eliminate the use of the sensitive structure, as shown in block 59 .
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A system, method and media for locating and defining process sensitive sites isolated to specific geometries or shape configurations within chip design data. Once a systemic process sensitive site is identified, a 3D design checking deck is coded and executed through a design checker on physical design data. Target match shapes are produced and embedded back into the design data. Pictures, maps and coordinates of process sensitive sites are produced and sent to a website library for reference.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from Korean Patent Application No. 10-2006-0043516 filed on May 15, 2006 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field
[0003] One or more embodiments of the present invention relate to an apparatus and method enhancing muscular movement, and more particularly, to an apparatus and method enhancing muscular movement using an electroactive polymer (EAP).
[0004] 2. Description of the Related Art
[0005] In general, haptic feedback techniques are broadly classified into force feedback techniques and tactile feedback techniques. Force feedback techniques are techniques that enable a user to feel forces and a sense of movement using a mechanical interface. Force feedback devices are commonplace. Examples of force feedback devices include feedback force joysticks that apply repulsive forces to a game gun when the user shoots the gun while playing a game, and feedback force steering wheels to which virtual impulses are applied when a car crash occurs. The field of medicine is one of the fields of science in which tactile feedback has been most widely used. With tactile feedback, a,doctor can conduct an operation on a virtual patient by referencing a 3D image that renders a three-dimensional anatomical structure, displayed in real time on a computer screen. Tactile feedback can be accomplished by stimulating mechanoreceptors of a user with a haptic device, or an array of small pins that is driven by compressed air or electricity, and can thus give a user the sensation that the user is actually touching skin.
[0006] Conventional apparatuses for encouraging muscular movement of a user are disclosed in U.S. Pat. No. 4,558,704 and Japanese Patent Laid-Open Gazette No. hei 10-280209.
[0007] In detail, U.S. Pat. No. 4,558,704 discloses a muscle stimulation system for patients with a paralyzed hand, particularly, a hand controller system that senses movement of the shoulder of a patient, having a paralyzed hand, with the aid of a sensor, provides the result of the sensing to a controller, and stimulates the patient's muscle under the control of the controller so that the patient can grab an object with the paralyzed hand. Japanese Patent Laid-Open Gazette No. hei 10-280209 discloses medical equipment for protection of the lower limbs. The medical equipment includes a power accumulation unit that reinforces the femoral muscle of a user. The medical equipment can prevent injury by assisting muscular contraction and encouraging muscle.
[0008] However, the aforementioned muscular movement encouraging apparatuses belong to a type of medical auxiliary equipment that can be worn by a user, and that can encourage muscular movement of the user. In order to use the aforementioned muscular movement encouraging apparatuses, a user must wear them with clothes on, and may accordingly feel heaviness on part of his/her body due to the weight of the necessary heavy components in each of the apparatuses.
SUMMARY
[0009] One or more embodiments of the present invention provide an apparatus and method enhancing muscular movement which is formed of fibers or pads as clothes that realize almost the same arrangement as that of the human muscles and can thus enhance the muscular movement of elderly people who have weak muscular strength.
[0010] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
[0011] To achieve at least the above and/or other aspects and advantage, embodiments of the present invention include an apparatus to enhance a muscular movement. The apparatus includes at least one muscular movement sensor to sense a result of an attempt to move a muscle, a movement information controller to analyze the sensed muscular movement, and generate muscular movement information based on the analyzed muscular movements, and a muscular movement actuator to enhance the movement of the muscle according to the generated muscular movement information by actively controlling a deformation of the muscle movement actuator over the surface of the muscle.
[0012] To achieve at least the above and/or other aspects and advantage, embodiments of the present invention include a muscular movement actuator apparatus including an electroactive polymer (EAP) formed as clothing wearable over a surface of a muscle, a plurality of electrodes placed in contact with opposite lateral sides of the EAP, an electrical circuit to operatively connect to the electrodes, whereby a voltage applied to the electrical circuit causes a deformation of the EAP to enhance a movement of the muscle.
[0013] To achieve at least the above and/or other aspects and advantage, embodiments of the present invention include a method for enhancing a movement of a muscle including placing a surface of the muscle in contact with fibers comprised of an electroactive polymer (EAP), sensing the movement of the muscle using a plurality of sensors, analyzing the sensed muscular movement, generating muscular movement information based on the analyzed muscular movement, and enhancing the movement of the muscle, according to the generated muscular movement information using the EAP, by actively controlling a deformation of the EAP over the surface of the muscle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of one or more embodiments, taken in conjunction with the accompanying drawings of which:
[0015] FIG. 1 illustrates a user who wears an apparatus for enhancing muscular movement according to an embodiment of the present invention;
[0016] FIG. 2 illustrates an apparatus, such as that illustrated in FIG. 1 , according to an embodiment of the present invention;
[0017] FIG. 3 illustrates two types of electroactive polymers (EAPs) and the characteristics of each of the two types of EAPs, according to an embodiment of the present invention;
[0018] FIG. 4 illustrates an explanation of the principles of realization of a muscular movement actuator, according to an embodiment of the present invention;
[0019] FIG. 5 illustrates an explanation for the action of a muscular movement actuator, according to an embodiment of the present invention;
[0020] FIG. 6 illustrates an explanation for the action of a muscular movement actuator, according to another embodiment of the present invention; and
[0021] FIGS. 7A and 7B illustrate an explanation for the action of a muscular movement actuator, according to another embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0022] Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Embodiments are described below to explain the present invention by referring to the figures.
[0023] FIG. 1 illustrates a user who wears an example apparatus 100 for enhancing muscular movement according to an embodiment of the present invention. Referring to FIG. 1 , the apparatus 100 may be used as an auxiliary artificial muscle that is formed of fibers and can thus be worn by a user. For example, the apparatus 100 may be formed into clothing wearable by a user, such as a glove, stocking, wrap, or other wearable clothing.
[0024] In detail, in an embodiment a user may wear the apparatus 100 in order to supplement muscular strength. When a user who wears the apparatus 100 moves his/her left arm, as indicated by FIG. 1 , a muscular movement sensor 110 of the apparatus 100 may sense the muscular movement of the user. Then, the result of the sensing may be analyzed, and an actuator, realized using an electroactive polymer (EAP) 130 a , may be driven according to the result of the analysis, thereby enhancing the muscular movement of the user. Here, the user may feel as if he/she moved his/her muscle on his/her own without the auxiliary aid of the apparatus 100 . The operation of the apparatus 100 , according to an embodiment of the present invention, will hereinafter be described in further detail with reference to FIG. 2 .
[0025] FIG. 2 illustrates an apparatus 100 , such as that illustrated in FIG. 1 . Referring to FIG. 2 , the apparatus 100 may include a muscular movement sensor 110 , a movement information controller 120 , a storage module 125 , and a muscular movement actuator 130 , for example.
[0026] When a user wears the apparatus 100 and causes to move a muscle that is, e.g., fully surrounded by the apparatus 100 , the muscular movement sensor 110 may detect the movement of the muscle. A sensor using optical fibers or a bioelectric sensor may be used as the muscular movement sensor 110 . Some sensing methods used by the muscular movement sensor 110 may be well known to one of ordinary skill in the art to which the present invention pertains, and thus, a detailed description thereof will be omitted.
[0027] The movement information controller 120 may analyze the muscular movement, sensed by the muscular movement sensor 110 , and generate muscular movement information based on the results of the analysis, for example to control movement of the muscle. The muscular movement information may include the strength and direction of the muscular movement sensed by the muscular movement sensor 110 .
[0028] The storage module 125 may store muscular movement information in a database according to a set of standards, for example. The movement information controller 120 may then control the muscular movement actuator 130 with reference to the muscular movement information stored in the storage module 125 .
[0029] In an embodiment, the movement information controller 120 may supply the muscular movement actuator 130 with an input voltage having an appropriate waveform with reference to the storage module 125 . Examples of the input voltage include, without limitation, voltages having various waveforms such as direct current (DC) voltages and alternating current (AC) voltages having a sinusoidal wave, a triangle wave, or a square wave.
[0030] The muscular movement actuator 130 may be supplied with the input voltage, and may enhance the muscular movement of the user according to the muscular movement information provided by the movement information controller 120 , or the muscular movement information stored in the storage module 125 , for example. The muscular movement actuator 130 may thus enhance the muscular movement of the user, thereby not only providing additional strength, but also potentially weakening or decreasing the muscular movement of the user, by selectively resisting the movement of the user, for example.
[0031] The storage module 125 may store muscular movement information such as the strength and direction of the muscular movement of the user by mapping the muscular movement information as a database according to a set of standards, for example, according to the gender and age of the user, part of the user's body surrounded by the apparatus 100 , and corresponding muscles, and the time when the user may use the apparatus 100 . The muscular movement information stored in the storage module 125 may further be updated for each of the standards. Then, when the user uses his/her muscles more intensely than he/she usually does, the muscular movement actuator 130 may reduce the strength of the muscular movement of the user according to the muscular movement information stored in the storage module 125 , for example. In addition, if a muscle movement exceeds a desired range because of weakness in a muscle, such as a weak bicep muscle, further potentially resulting in the dropping of a held item, an opposing movement force may be generated to maintain the normal holding position.
[0032] As an example of increasing the strength, it may be assumed that a muscular strength of one hundred, on a hypothetical scale, is needed to lift a predetermined object. A user who can exert a muscular strength of up to eighty, on the hypothetical scale, can lift the predetermined object by making up for a deficit in muscular strength of twenty with the aid of the apparatus 100 . A user who can exert a muscular strength of up to ninety, on a hypothetical scale, can also lift the predetermined object by referencing the muscular movement information stored in the storage module 125 and making up for a deficit in muscular strength of ten, on a hypothetical scale, with the aid of the apparatus 100 .
[0033] The structure of the muscular movement actuator 130 will hereinafter be described in detail. The muscular movement actuator 130 may include an EAP that can be configured as fiber, e.g., tissue resembling human muscle tissue, and include a pair of electrodes that contact the lateral sides of the EAP, although other quantities of electrodes may be used, and an electric circuit that applies a voltage to the electrodes. The muscular movement actuator 130 may generate additional muscular strength or displacement for the user by responding to a signal obtained through conversion by the movement information controller 120 , and an actuator interface (not shown).
[0034] The actuator interface (not shown) may be arbitrarily connected between the muscular movement actuator 130 and the movement information controller 120 , and may convert a signal generated by the movement information controller 120 into an appropriate signal for driving the muscular movement actuator 130 , for example. Examples of the actuator interface may include a power amplifier, a switch, a digital-to-analog (DAC) converter, an analog-to-digital converter (ADC), and other components.
[0035] Two types of EAPs and the physical characteristics of each of the two types of EAPs will hereinafter be described in detail with reference to FIG. 3 , noting that alternatives are equally available.
[0036] EAPs are polymers that are manufactured and processed to reflect a wide range of physical and electrical properties. When EAPs are activated by applying a voltage, they display a significant size or shape distortion or deformation. The degree of deformation of EAPs is dependent on the length, width, thickness, and radial direction of the material of each EAP. In general, EAPs are deformed by 10-50% when activated. Given that piezoelectric materials are generally deformed by less than 0.3%, the degree of deformation of EAPs is highly distinctive. EAPs can also be precisely controlled using an appropriate electric system.
[0037] EAPs are generally small, easy to control, consume small amounts of power, achieve high response speeds, and are inexpensive. EAPs are thus, hereby suggested to be widely employed in the field of artificial muscles, and research on potential applications of EAPs as artificial muscles has been vigorously conducted.
[0038] EAPs output an electric signal when they undergo physical deformation due to external forces. Thus, EAPs can be used as sensors. Since most EAP materials generate an electrically measurable electrical potential difference, EAPs can also be used as strength, location, velocity, acceleration, and pressure sensors. Further, since most EAPs have bidirectional properties, EAPs can be used as sensors or actuators.
[0039] Examples of EAPs may include EAP gels, ionic polymer metal composites (IPMC), and electrostrictive polymers. The operating principles of most EAP materials are based on ionic movements inside and outside a polymer network.
[0040] EAPs are broadly classified into dry polymers using a dielectric material and wet polymers using an ionic material. The upper view and the lower view of FIG. 3 respectively illustrate a dry polymer and a wet polymer.
[0041] Referring to the upper and lower views of FIG. 3 , each of the dry and wet polymers may be formed as a sandwich made up of a dielectric or ionic polymer 130 a and two conductive/compliant electrodes 130 b that are on the opposite sides of the dielectric or ionic polymer 130 a . When a high electric field (e.g., an electric field of several hundreds or thousands of volts) generated by an electric circuit 130 c is applied, the suction force of the electrodes 130 b increases and thus presses on the dielectric or ionic polymer 130 a that is interposed between the electrodes 130 b , thereby causing a significant deformation of the dielectric or ionic EAP 130 a so that the dry or wet polymer can elongate or bend in one direction. Here, the degree of deformation of the dry or wet polymer may be about 50%.
[0042] Referring to the upper view of FIG. 3 , two electrodes 130 b contact an EAP 130 a , having a predetermined thickness, on the opposite sides of the EAP 130 a , for example. Each of the electrodes 130 b is formed of a conductive polymer layer. In order for the electrodes 130 b to be deformed along with the EAP 130 a , the electrodes 130 b should be compliant as well as conductive. An initial state of the EAP 130 a when the electrodes 130 b are not supplied with power by an electric circuit 130 c is illustrated in the left part of the upper view of FIG. 3 . Once the electrodes 130 b are supplied with power by the electric circuit 130 c , the thickness of the EAP 130 a decreases, and thus, the EAP 130 a spreads wide between the electrodes 130 b , as illustrated in the right part of the upper view of FIG. 3 . Here, the electrodes 130 b that are compliant are deformed along with the EAP 130 a.
[0043] Referring to the lower view of FIG. 3 , two electrodes 130 b contact an EAP 130 a , having a predetermined thickness, on the opposite sides of the EAP 130 a , for example. Each of the electrodes 130 b may be formed of a conductive polymer layer. In an embodiment, in order for the electrodes 130 b to be deformed along with the EAP 130 a , the electrodes 130 b should be compliant as well as conductive. An initial state of the EAP 130 a when the electrodes 130 b are not supplied with power by an electric circuit 130 c is illustrated in the left part of the lower view of FIG. 3 . Once the electrodes 130 b are supplied with power by the electric circuit 130 c , ions in the EAP 130 a rush into a cathode, thereby causing a deformation of the EAP 130 a so that the EAP 130 a bends like a bow, as illustrated in the right part of the lower view of FIG. 3 . Here, the electrodes 130 b that are compliant bend along with the EAP 130 a.
[0044] The principles of realization of an actuator using the wet polymer illustrated in the lower view of FIG. 3 will hereinafter be described in detail with reference to FIG. 4 . Referring to FIG. 4 , an EAP 130 a having a uniform curvature may be formed as a wave, for example, one of a cathode 130 b (−) and an anode 130 b (+) may be inserted into curvature portions of the EAP 130 a , and an anode 130 b (+) or a cathode 130 b (−) (whichever of the cathode 130 b (−) and the anode 130 b (+)connected to none of the curvature portions of the EAP 130 a ) may be inserted into the middle of the EAP 130 a . When the anode 130 b (+) and the cathode 130 b (−) are supplied with power by an electric circuit 130 c , the curvature of the EAP 130 a changes in the direction of a current, and thus, the EAP 130 a either contracts or elongates.
[0045] Examples of the action of a muscular movement actuator using an EAP will hereinafter be described in detail with reference to FIGS. 5 through 7B .
[0046] FIG. 5 illustrates an explanation for the action of a muscular movement actuator according to an embodiment of the present invention. Referring to FIG. 5 , an EAP 130 a may be formed as a single wavy layer having a uniform curvature, a pair of electrodes 130 b may be formed by connecting one of an anode 130 b (+) and a cathode 130 b (−) to an upper curvature portior of the EAP 130 a and connecting whichever of the anode 130 (+) and the cathode 130 b (−) is left unconnected to the upper curvature portion of the EAP 130 a to a lower curvature portion of the EAP 130 a . When a current is applied to the electrodes 130 b by an electric circuit 130 c that is connected to a power supply, the EAP 130 a bends in one direction, thereby causing a deformation of the EAP 130 a so that the EAP 130 a contracts.
[0047] FIG. 6 illustrates an explanation for the action of a muscular movement actuator according to another embodiment of the present invention. Referring to FIG. 6 , an EAP 130 a may be formed as a double wavy layer having a uniform curvature. A pair of electrodes 130 b may be formed by connecting one of an anode 130 b (+) and a cathode 130 b (−) to both upper and lower curvature portions of the EAP 130 a and connecting whichever of the anode 130 b (+) and the cathode 130 b (−) is connected to none of the upper and lower curvature portions of the EAP 130 a to the interface between the upper layer and the lower layer of the EAP 130 a . When a current is applied to the electrodes 130 b by an electric circuit 130 c that is connected to a power supply, the EAP 130 a further bends in one direction so that the EAP 130 a further contracts.
[0048] FIGS. 7A and 7B illustrate an explanation for the action of a muscular movement actuator according to another embodiment of the present invention. Referring to FIGS. 7A and 7B , an EAP 130 a may be formed as a cylinder that extends longer in a longitudinal direction than in a latitudinal direction. A pair of electrodes 130 b may be formed by connecting one of an anode 130 b (+) and a cathode 130 b (−) to the outer circumferential surface of the EAP 130 a and connecting whichever of the anode 130 b (+) and the cathode 130 b (−) is left unconnected to the outer circumferential surface of the EAP 130 a to the inner circumferential surface of the EAP 130 a which is the outer circumferential surface of a central axial member of the EAP 130 a , for example.
[0049] In detail, Referring to FIG. 7A , the volume of a central portion of the EAP 130 a varies, and thus, the central axial member of the EAP 130 a extends. Accordingly, the EAP 130 a elongates. FIG. 7B illustrates the opposite situation to the situation illustrated in FIG. 7A . In other words, referring to FIG. 7B , the volume of an outer circumferential portion of the EAP 130 a increases, and thus, the diameter of the EAP 130 a increases so that the EAP 130 a contracts along the longitudinal direction.
[0050] The apparatus 100 may be realized as outerwear or underwear that can be worn by a user, for example. In this case, it is possible to facilitate user activities by providing a user who wears the apparatus 100 with almost the same feeling of wearing outerwear or underwear. The apparatus 100 may enhance the muscular movement of a user and may serve as auxiliary artificial muscles for a user.
[0051] The apparatus for enhancing muscular movement according to the present invention may be realized, using fibers, as clothes that provide almost the same arrangement as that of the human muscles, thereby enhancing muscular movement of individuals, such as elderly people who have weak muscular strength.
[0052] In addition, the apparatus for enhancing muscular movement according to the present invention may prevent excessive muscular movement of a user who has weak muscular strength by limiting the movement of the individuals and can correct posture so that a user can properly maintain a desired posture.
[0053] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
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An apparatus to enhance muscular movement is provided. The apparatus includes at least one muscular movement sensor to sense a result of an attempt to move a muscle, a movement information controller to analyze the sensed muscular movement, and generate muscular movement information based on the analyzed muscular movements, and a muscular movement actuator to enhance the movement of the muscle according to the generated muscular movement information by actively controlling a deformation of the muscle movement actuator over the surface of the muscle.
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BACKGROUND OF THE INVENTION
This invention relates generally to an apparatus for treating the semiconductor wafer so that individual units which may be single devices or complex integrated circuits can be easily separated from the semiconductor wafer in which they are formed. More particularly, the invention relates to an apparatus that aligns a semiconductor wafer to a fixed reference and emits an aligned laser beam to traverse the reverse side of the wafer such that easily fractured regions can be created in the region of the wafer traversed by the laser beam.
Methods and apparatus for dividing semiconductor devices from monolithic wafers and sorting the semiconductor devices are known. One such apparatus shown in U.S. Pat. No. 3,583,561 tests each device in a wafer optically, encodes the test data, and prepares a photographic record thereof. After testing the wafer is mounted on a pressure sensitive web together with the coded photographic record and the wafer broken to separate the respective devices. By reading the coded record, output signals can be utilized to pick each of the separated devices from the web and placed into a preselected station with devices of common characteristics. Unless great care is taken in mounting the photographic record and the wafer significant discrepancies in the removal of the selected devices will occur.
It is also known that substrates can be aligned prior to laser dicing as is taught in U.S. Pat. No. 3,816,700. This patent discloses the alignment of a wafer with its active face up, in a portable vacuum chuck that will hold the aligned wafer in a set position. Once the wafer is aligned the portable vacuum chuck is then transferred to a holding device which can be placed under a laser scribing apparatus which scribes the active face of the aligned wafer with a laser beam in accordance with the preset alignment. The action of the laser beam in dicing the wafer creates a residue on the face of the wafer which can interfere with the subsequent handling and mounting of the diced units.
To avoid this, the concept of laser dicing from the backside of the wafer away from the active units was considered. Such cutting of semiconductor wafers from the reverse side with the laser beam is taught in U.S. Pat. No. 3,824,678 which teaches that a wafer can be aligned in an inverted position by using an infrared microscope and subsequently dicing the wafer. Such infrared microscopes have poor resolution thus requiring that the units to be separated from the wafer be created further apart in the wafer so that the poor infrared resolution can be compensated for. Additionally such infrared microscopes are complex, difficult to use, and expensive to purchase. Also they do not permit direct viewing of the semiconductor wafer surface.
Accordingly, the present invention which describes a complete system for the dicing of individual semiconductor units from an integral wafer avoids the difficulties and disadvantages encountered by these prior art systems.
SUMMARY OF THE INVENTION
Broadly speaking the complete system of the present invention provides for aligning an integral wafer containing such units defined in the front surface thereof to a fixed orientation and exposing the reverse or back surface of the water to a laser beam such that an easily fractured region can be created in the wafer between each of the units to be separated and removed from the integral wafer.
The invention further provides for the laser treated wafer to be mounted on a pressure sensitive tape stretched across a receiving frame so that it again can have its front side exposed for testing after the laser dicing has occurred. While still mounted on the tape, the wafer may be fractured into individual units and placed in a suitable transfer machine where units of like characteristics can be selectively removed from the tape and transferred to suitable receptacles.
The present invention by dicing the semiconductor wafer from the reverse side thereof, not only permits denser packing of the circuits or devices created on the wafer but also avoids distribution of undesirable residues on the front or active face of the unit.
It is, therefore, an object of the invention to describe a complete system for the laser dicing of a monolithic semiconductor wafer in which the orientation of each of the units defined in the wafer is aligned to a fixed position and maintained in that relationship during dicing, testing, and sorting.
It is another object of the present invention to describe an apparatus which aligns a semiconductor wafer, inverts it, and exposes its reverse side to a laser beam which laser beam defines in the material between the semiconductor units an easily fractured region. The laser treated wafer may be then mounted on a tape so that it may be maintained as a single entity until it is tested.
It is still another object of the invention to teach an integrated system adapted to align a semiconductor wafer into a preferred orientation during the transfer of the wafer through a dicing station and subsequent operations.
It is still a further object of the invention to teach a method of treating the nonactive backside of semiconductor wafer with a laser beam such that damage of contamination to the front side of the wafer in the area treated by the laser beam is avoided or eliminated.
DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will be more fully understood from the accompanying drawings in which
FIG. 1 is an isometric view of an apparatus that aligns, inverts, laser dices, and mounts the wafer to a carrier for further handling.
FIG. 2 illustrates schematically the aligning, inverting, and laser dicing steps of the present invention.
FIG. 3 illustrates in detail the alignment portion of the apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
In describing the apparatus of the invention reference will be made to each of the FIGS. 1, 2, and 3. To initially set up the apparatus shown in FIG. 1 such that it will be repetitive with a high degree of accuracy, it is necessary to place a transparent wafer or a mask 10, as shown in FIG. 2, on the water prealigner vacuum chuck 15. The body of this mask is made of a material such as glass which is transparent to visible light. The mask was formed on its top surface 10a an exact photographic duplicate of the semiconductor devices as they are formed in the wafer to be diced in the apparatus.
For a number of reasons not pertinent to the present invention semiconductor wafers are usually provided with a flat edge which is parallel to one of the major crystallographic axes in the wafer. During the manufacture of semiconductor devices in the wafer, care is taken to assure that these devices are positioned with respect to this flat edge. Also it should be noted that in the formation of such devices, they are formed in the wafer such that one set of two mutually orthogonal sets of kerf regions, separating the devices from each other, is substantially parallel to the edge. Also at least one pair of alignment marks are provided on the wafer surface with the devices. Usually each such alignment mark is placed in a respective intersection of such kerf regions to define the intersection and aid in the exact positioning of such wafers during their manufacture.
Because this flat edge exists on the wafer to be diced, the mask 10 is also provided with such a flat edge 14. The chuck 15 takes advantage of this flat edge 14 and to do so is provided with a stop 17 against which the edge 14 may be butted. Because the mask 10, as shown in FIG. 2, is a duplicate of the wafer to be diced it is provided with a pair of widely separated alignment marks 18 and 19.
Once the mask 10 is mounted on the chuck 15 a vacuum is drawn through hose 16 and ports 20 by a suitable apparatus (not shown) to hold the mask in a fixed position on the chuck 15. While the mask is so held on the chuck 15, the chuck 15 is pulled, with a hydraulic piston 22, along a pair of parallel rails 23 and 24 to a set position under a split image microscope 21. At least one of the rails, in this case rail 24, is provided with an adjustable stop 25 against which the chuck is always pulled by the piston 22. This stop 25 assures that the chuck always goes to the same fixed position under the microscope 21. As the vacuum chuck 15 is drawn in under the microscope 21 the back surface 10b of mask 10 is brought into contact with a rotatable, x and y adjustable, alignment pedestal 30. Once the pedestal 30 is contacting the back of the mask 10a a vacuum is drawn through a central opening 29 in pedestal 30 and the vacuum on chuck 15 is released so that the wafer is now held only by the pedestal. The wafer is now aligned to a suitable reticle (not shown) which is provided in the microscope 21 by rotating the pedestal 30 and adjusting it in the x and y direction. The x-y adjustment is made by manipulating a joy stick 32 while the rotational adjustment is made by knob 33.
This pedestal adjustment mechanism lies beneath the cover plate 31 and is shown in greater detail in FIG. 3. The pedestal 30 is connected by an L-shaped arm 34 to the joy stick 32 which is secured to a pivotable plate 35. The plate 35 pivots with respect to a base plate 37, around a post 38 secured to the base plate 37. The plate 35 is also provided with a rectangular opening 40 in which there is positioned a circular cam 39 which is mounted off center with respect to the shaft 33a extending up to knob 33. A spring 41 connected between the base plate 37 and the pivotable plate 35 applies a positive bias to the plate 35 and draws the plate 35 against the cam 39. Movement of the joy stick 32 causes the pedestal 30 to move in an x or y direction. Rotation of the knob 33 causes the off center mounted cam 39 to be driven around within the rectangular opening 40 which in turn causes the plate 35, and hence the alignment pedestal 30, to be rotated around the post 38.
Once the wafer has been positioned and aligned to the fixed pattern set by the reticle in the microscope 21, the vacuum in the alignment pedestal 30 is broken and the wafer released from the pedestal 30. Simultaneously, the vacuum to vaccum chuck 15 is again activated holding the aligned wafer fixedly against the chuck 15. Once the aligned wafer is again securely fixed on the chuck 15, the chuck 15 is driven from under the microscope back to its original position by the piston 22. As shown in FIG. 2, the rail 24 passes through the center of a hinge portion 15a of the vacuum chuck 15. The hinge portion 15a of the vacuum chuck 15 is provided with a slot 15b that will, when the chuck is driven back to its original position, engage a pin 24a in rail 24. This rail 24 is directly coupled to geared pully 42 driven by a belt 42a which passes over another geared pully 42b driven by a rack and pinion mechanism 43. Activation of this mechanism 43 causes the chuck 15 to be rotated around the axis of rail 24 such that the upper surface 10a of the transparent mask 10 is now positioned adjacent a porous dicing vacuum hold down 45. This hold down 45 is in a predetermined loading position butting against pins 46 and 47 which sit in a vee notch 48 and step 49, respectively, provided on one side of the hold down 45. These pins 46 and 47 are set into a guide plate 50 firmly attached to the base plate 37 and act to position the hold down plate 45 in exactly the same position each time it is butted against these pins.
As the face 10a of mask 10 parallels the face of hold down 45 a vacuum is drawn by suitable apparatus (not shown) through hose 44 causing mask 10 to be drawn towards the hold down 45. Simultaneously the vacuum holding the mask 10 on chuck 15 is broken. Thus the mask 10 becomes secured to the hold down 45.
The chuck 15 is now returned back to its initial position by reversing mechanism 43.
Because the mask 10 has been inverted, the front surface 10a of mask 10 is now held against the hold down 45 and the back surface 10b of the mask is exposed. As shown in FIG. 2, the alignment marks are now against the hold down 45.
The guide plate 50 is provided with a pair of edge guides 51 and 52 that engage suitable slots 55 and 56 on the edge of hold down 45. Rails 53 and 54 support the underside of hold down 45 above guide plate 50. Once the mask 10 has been loaded on the hold down 45, the hold down 45 is slid on these guides and rails to transfer it to top 55a of a dicing table 55. This dicing table is also provided with a pair of edge guides 56 and 57 and 58 and 59 which guide and support the hold down 45. On table top 55a the dicing table 55 is also provided with locating pins 60 and 61 which respectively engage vee notch 62 and step 63 on the opposite side of hold down 45 from notch 48 and step 49. These locating pins 60 and 61 serve to assure that the hold down 45 is always in the same place with respect to dicing table top 55a. Once the hold down has been seated against pins 60 and 61, optical axis 70 of the laser head 71 is optically aligned with a first one of the alignment marks 18 or 19 on the transparent mask 10. This is accomplished by viewing the alignment mask through the microscope 72, which is incorporated in the laser head 70, and which has optical axis on the same optical axis as the laser head, and moving the top 55a of the table 55 in the x-y direction with a stepping motor 66 and rotating the table top 55a with knob 67 which drives a screw mechanism (not shown) under table top 55a.
After lining up the first one of alignment marks with the laser axis 70 the table 55 is shifted to the side and the second mark aligned with the laser axis 70, by again adjusting the table top 55a. Once the table top 55a has been properly adjusted such that the laser axis will, when traversed across the mask, travel along the kerf areas and intercept both alignment marks 18 and 19. Thus, any laser beam passing along the axis 70 will act in the kerf area of the wafer as the wafer is shifted under the laser head. The table 55 can be incremently stepped under the laser beam in both the x and y direction, by the stepping motor 66 so that the laser axis traverses the orthogonal kerf areas. The apparatus of FIG. 1 is now aligned. At this time the hold down 45 is returned to its home position so that notch 48 and step 49 is abutting pins 46 and 47, and the vacuum released such that the mask 10 can be removed.
Because the apparatus is now aligned, any wafer, similar to mask 10, aligned to the retical in microscope 21 will when transferred under the laser head follow a kinetic path, i.e., always go to exactly the same position as did the mask 10 used for alignment of the apparatus.
An opaque semiconductor wafer having alignment marks on its front surface is now placed on vacuum chuck 15 and transferred under microscope 21 and aligned to the reticle therein in exactly the same way the mask 10 was aligned.
Once aligned this opaque wafer is carried by vacuum chuck 15 and the chuck rotated around the rail 24 such that the wafer is inverted on the vacuum hold down 45. Again the vacuum on hold down 45 is activated and the vacuum on chuck 15 broken causing the wafer to be transferred on the hold down 45. When this hold down 45 is now moved under the laser head such that it is firmly seated against pins 60 and 61, it wll be positioned with respect to the laser axis 70 as was the transparent mask 10. The laser can now be activated such that the laser beam passes along the laser axis 70 and impinges on the back side of the wafer. Because the wafer is positioned in exactly the same place the mask 10 was positioned, the laser beam will act only in the kerf regions of the wafer as the table 55 is stepped under the laser beam.
The laser beam is caused to pass over the back surface of the wafer along predefined orthogonal paths which lie in the kerf regions between the integrated circuits disposed in the front surface of the wafer. Preferably the laser beam is of such intensity that the material in the kerf regions, between the units disposed in the wafer, is not fully eroded out of the kerf regions but rather is converted into an oxide of the material of which the wafer is composed. For example, when the wafer is silicon the kerf regions become converted to silicon dioxide.
When the wafer for example is silicon and has a thickness of 0.015 inches then a beam whose intensity is 50 joules erodes away about 40% of this thickness and converts the remaining thickness to silicon dioxide.
Once the laser beam has followed its predetermined paths, the vacuum chuck 45 is withdrawn from beneath the laser head 71 back to its home position such that the notch 48 and the step 49 again abut against the respective alignment pins 46 and 47.
Meanwhile, a frame 81 has been prepared with adhesive coated tape 82 on one side thereof. The frame 81 is also provided with a notch 83 and a step 84. The center of the frame is provided with an aperture 85 which is larger than the wafer on the hold down 45. The adhesive coated tape 82 is applied to the frame 81 such that in the center of the aperature 85 the adhesive coating is exposed. The tape 82 is further disposed across the frame 81 with sufficient tension to assure a deflection of no more than 50 micro inches occurs in the tape in the center of the aperature when a pad 1/2 inch in diameter is applied to the back side of the tape with a force of 30 grams. The frame 81 carrying the tape 52 is then disposed upon a frame support 86. The frame support 86 has alignment pins 87 and 88 which are adapted to mate with the notch 83 and the step 84 respectively. The frame support 86 is also provided with four vacuum ports 90, 91, 92, and 93 disposed around the four corners of the frame support such that the frame 81 can be securely retained in a fixed position against the frame support and with a central port 94 through which air can be forced. When the vacuum hold down 45 is withdrawn from under the laser head 71 to its home position the frame support 86 is rotationally translated around a hinge 86a in a counterclockwise direction such that the frame 81 is forced against the hold down 45. When the frame support 86 contacts the hold down 45 a pulse of air, passing through port 94, assures that the coated tape 82 is forced against the back side of the laser treated wafer. Simultaneously the vacuum holding the wafer on the vacuum hold down 45 is removed releasing the wafer from the hold down. The wafer now adheres to the coated tape 82. With the release of the wafer from chuck 45 the frame support 86 is lifted off the vacuum chuck 45 and returned to its original position by rotating it in a clockwise direction around the hinge 86a. Once the frame support 86 has returned to this position the vacuum holding the frame 81 to the frame support is released and the frame removed. Because the frame support 86 has reinverted the wafer the front surface of the wafer is again exposed.
The frame 81 keeps the wafer in the aligned position and permits further handling and testing of the wafer without undue breakage.
While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.
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An apparatus for treating a wafer of semiconductor material so that individual devices which may be simple devices or complete complex integrated circuits defined on the front surface of the wafer can be easily separated from the wafer. The apparatus aligns the wafer to a fixed reference position, inverts the aligned wafer to expose its backside and transfers it with controlled motion to a set position under a laser beam apparatus. The laser beam scans the backside of the wafer to create in the kerf area between each of the devices an easily fractured region. While maintaining the wafer alignment the laser treated wafer may be transferred to a flexible pressure sensitive tape tensioned across the frame which maintains the wafer alignment. The wafer, while on the frame can be tested, fractured into respective individual devices, and selectively removed from the tape.
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BACKGROUND OF THE INVENTION
This invention relates to an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor using an organic photoconductive material.
Generally used as photoconductive materials for electrophotographic photoreceptors are inorganic materials such as selenium (Se), cadmium sulfide (CdS), zinc oxide (ZnO), amorphous silicon (a--Si) and the like. Photoreceptors using such inorganic photoconductive materials are used in such a manner that the photoreceptors are charged in the dark by means of, for example, a charging roller and then subjected to image-wise exposure to selectively neutralize the charges only on the exposed portions, and the electrostatic latent image thus formed is thereafter visualized with a developer to form an image. Such photographic photoreceptors are basically required to have (1) an ability to be charged to an adequate potential in the dark and (2) a function of neutralizing the surface charges by exposure to light. However, the above-mentioned inorganic photoconductive materials have merits and demerits and, for example, selenium (Se) satisfies sufficiently the requirements (1) and (2) but is inflexible and difficult to mold into a film. In addition, it is sensitive to mechanical impact and hence must be carefully handled. Amorphous silicon (a--Si) has such a demerit that severe production conditions are required and hence its production cost becomes high.
Recently, function-separated type organic photoreceptors have been mainly used which have a charge-generating layer consisting of a phthalocyanine compound or an azo compound which is known as an organic photo-conductive material having laminated thereto a charge-transfer layer consisting of a hydrazone compound or the like.
In such organic photoreceptors, charge-transfer materials which are effective to a specific charge-generating material are not always effective to other charge-generating materials. That is, it is necessary to adequately combine a charge-generating material with a charge-transfer material, and if the combination is inadequate it will be impossible to obtain an electrophotographic photoreceptor excellent in characteristics such as sensitivity and the like.
On the other hand, a laser printer has recently been extensively developed which uses as a light source a semiconductor laser having a wavelength in the near infrared region. The electrophotographic photoreceptors applied to this field are required to have high sensitivity to light having a wavelength in the oscillatory wavelength region of a semiconductor laser (about 760-850 nm), and simultaneously, a short response time which is the time required until the charges are neutralized by exposure to light becomes a great factor required for the photoreceptor.
For meeting said requirement, attention is directed to a phthalocyanine compound among charge-generating materials because it is sensitive to semiconductor wavelength region.
Of phthalocyanine pigments, metalophthalocyanine compounds have been much studied, and hydroxytitanium phthalocyanines having different crystal forms have been reported as particularly useful compounds. However, the film formed from the above phthalocyanine is chemically instable, and when it is contacted with, for example, a solvent its crystal form is changed, whereby a great difference is caused in respect of electrophotographic characteristics such as charge potential, residual potential and the like. A solution of this problem has been strongly desired.
However, there have been found neither phthalocyanine compounds as charge-generating materials excellent in electrophotographic characteristics in the oscillatory wavelength region of semiconductor laser nor charge-transfer materials to be adequately combined with the phthalocyanine compounds.
In order to solve the above problems of prior art, the present inventors have made extensive research on various organic compounds as the charge-transfer materials to be combined with the phthalocyanine compound as the charge-generating material to find that a specific butadiene compound is very effective to enhance the electrophotographic characteristics, and as a result, have obtained a photoreceptor having high sensitivity and excellent light responsibility.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an electrophotographic photoreceptor freed from the above-mentioned disadvantages of the prior art, particularly having high sensitivity to light having a wavelength in the oscillatory wavelength region of semiconductor laser and having a short response time.
It is another object of the invention to provide an electrophotographic photoreceptor excellent in electrophotographic characteristics such as charge potential, residual potential and the like.
Other objects and advantages of this invention will become apparent from the following description.
According to this invention, there is provided a laminate type electrophotographic photoreceptor having a charge-generating layer and a charge-transfer layer on a photoconductive support, said charge-generating layer containing a hydroxytitanium phthalocyanine and the charge-transfer layer containing a butadiene compound represented by formula (I); ##STR2##
In this invention, the charge-transfer layer further contains a monophenol type antioxidant, the weight ratio of the monophenol type antioxidant/the compound of formula (I) ranging from 5/95 to 40/80.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-sectional view of a negatively charged photoreceptor according to this invention, and FIG. 2 shows a cross-sectional view of a positively charged photoreceptor according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
When the charge-generating layer is formed from a hydroxytitanium phthalocyanine having a main peak at a black angle (2θ±0.2°) of 27.3° in the X-ray diffraction spectrum, very good characteristics as an electrophoto-graphic photoreceptor are obtained. In particular, the photoreceptor having said charge-generating layer has high sensitivity to light having a wavelength in the oscillatory wavelength region of semiconductor laser and has a very low residual potential.
The charge-transfer material used in this invention is a butadiene compound represented by the above-mentioned formula (I) and is dissolved in an electrically insulating binder.
The proportions of the components in the charge-transfer layer in this invention are preferably such that the weight ratio of the compound of formula (I)/the binder ranges from 0.5/1.0 to 1.2/1.0 and the weight ratio of the monophenol type antioxidant/the compound of formula (I) ranges from 5/95 to 40/80, preferably from 5/95 to 20/80, in order to obtain much better light responsibility than conventional organic photoreceptors.
In this invention, the charge-transfer layer containing a monophenol type antioxidant may be formed by adding the monophenol type antioxidant to the butadiene compound represented by formula (I), dissolving the resulting mixture in the binder and forming the resulting solution into a film. In the film thus formed, the internal stress is reduced and no cracks are caused even when a stimulus due to adhesion of an oil, a fingerprint or the like is given thereto. The amount of the mono-phenol type antioxidant added is preferably 5-20 parts by weight per 100 parts by weight of the total amount of the antioxidant and the butadiene compound of formula (I). When the amount is less than 5 parts by weight, cracks tend to be caused and the chargeability tends to become low. On the other hand, when the amount exceeds 20 parts by weight, the residual potential tends to become high.
The monophenol type antioxidant includes 2-tert-butyl-4-methoxyphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethyl-phenol and 2,6-di-tert-butyl-4-methoxyphenol. Other antioxidants such as polyphenol type antioxidants, bisphenol type antioxidants, amine type antioxidants, salicylic acid type photostabilizers, benzophenone type photostabilizers and the like cannot be used in this invention because with the polyphenol type antioxidants cracks are caused owing to adhesion of an oil, a fingerprint or the like, and with the bisphenol type antioxidants, amine type antioxidants, salicylic acid type antioxidants and benzophenone type photostabilizers, the formation of cracks can be inhibited but the residual potential becomes high and hence the function as a photoreceptor is deteriorated.
The structure of the electrophotographic photoreceptor of this invention is as shown in FIGS. 1 and 2, and FIG. 1 shows a negatively charged, function-separated type, double layer structure in which a charge-generating layer 2 is formed on a substrate 1 and a charge-transfer layer 3 is formed on the charge-generating layer 2. FIG. 2 shows a positively charged, double layer structure in which a charge-transfer layer 3 is formed on a substrate 1, a charge-generating layer 2 is formed on the charge-transfer layer 3. Incidentally, in this invention, in each of FIGS. 1 and 2, a further charge-transfer layer may, if necessary, be formed and an undercoat layer may, if necessary, be provided on the substrate.
The electrophotographic photoreceptor of this invention which has the structure of FIG. 1 consisting of the substrate 1, the charge-generating layer 2 and the charge-transfer layer 3 is prepared by dissolving the butadiene compound of formula (I), namely 1-p-dibenzylaminophenyl-1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene, a monophenol type antioxidant and an electrically insulating binder in a suitable solvent to prepare a coating solution, and coating the coating solution on the charge-generating layer 2 formed on the support in the following manner.
The charge-generating layer applied to this invention may be prepared by vapor-depositing the above-mentioned specific hydroxytitanium phthalocyanine or coating a dispersion thereof in a binder on the support. When the vapor-deposition is effected, it is deposited in a film thickness of 100-3,000 Å, and then immersed in an alcohol such as methanol or the like at a temperature of 25°-40° C. for a period of 1-10 seconds to cause crystal modification into a crystal form having a main peak at a black angle (2θ±0.2°) of 27.3° in the X-ray diffraction spectrum. In the case of the dispersion-coating method, the charge-generating layer may be formed by treating a hydroxytitanium phthalocyanine to convert the same into an amorphous crystal, milling the same in an alcoholic solvent to convert the same into a crystal system having a main peak at a black angle of 27.3° of the X-ray diffraction spectrum, adding a ketone type solvent in which the crystal system is well dispersed, to disperse the crystal system in the solvent and then coating the resulting dispersion of a hydroxytitanium phthalocyanine on the support.
The electrically insulating binder includes thermoplastic resins such as polyester, polycarbonate, polyvinyl chloride, polyvinyl butyral, acrylic resin and the like, and these may be used alone or in admixture of two or more.
The solvent for preparing the coating solution includes ethers such as tetrahydrofuran, dioxane and the like; ketones such as methyl ethyl ketone, cyclohexanone and the like; alcohols such as methanol and the like; aromatic hydrocarbons such as toluene and the like; and chlorinated hydrocarbons such as methylene chloride and the like. These may be used alone or in admixture of two or more.
The electroconductive support includes plate and drum of aluminum, nickel and the like; plastic film having vapor-deposited or plated thereon a metal such as aluminum, copper, nickel or the like; and sheet and drum of a mixture of a plastic material and electroconductive powder such as carbon powder.
DESCRIPTION OF PREFERRED EMBODIMENTS
This invention is explained in more detail below, referring to Examples which are merely by way of illustration and not by way of limitation.
Example 1
A dispersion of a hydroxytitanium phthalocyanine in polyvinyl butyral BM-1 (manufactured by Sekisui Kagaku Kogyo K.K.) as a binder was applied to an aluminum drum by dip coating in a thickness of 0.1 μm to form a charge-generating layer. Subsequently, 1-p-dibenzylaminophenyl-1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene/polycarbonate Z (Mitubishi Gas Chemical Co., Ltd.) =0.8/1.0 by weight and 2,6-di-tert-butyl-4-methylphenol/1-p-diebenzylaminophenyl -1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene=5/95 by weight were dissolved in chloroform to prepare a coating solution, the resulting coating solution was applied onto the charge-generating layer by dip coating and the resulting coating was dried at 100° C. for one hour to form a charge-transfer layer having a film thickness of 20 μm, whereby a photoreceptor was formed.
Example 2
A hydroxytitanium phthalocyanine was heated at a vacuum of 10 -6 mmHg to vapor-deposit the same on an aluminum drum in a thickness of 2 μm to form a charge-generating layer. Subsequently, in the same manner as in Example 1, a charge-transfer layer was formed thereon to prepare a photoreceptor.
Comparative Example 1
The same procedure as in Example 1 was repeated, except that the 1-p-dibenzylaminophenyl-1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene was replaced with o-methyl-p-dibenzylaminobenzaldehyde(diphenylhydrazone) to prepare a photoreceptor.
Comparative Example 2
The same procedure as in Example 1 was repeated, except that p-diethylaminobenzaldehyde(diphenylhydrazone) was substituted for the 1-p-dibenzylaninophenyl-1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene to prepare a photoreceptor.
Comparative Example 3
The same procedure as in Example 1 was repeated, except that 1,1-bis(p-diethylaminophenyl)-4,4-diphenyl-1,3-butadiene was substituted for the 1-p-benzylaminophenyl-1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene to prepare a photoreceptor.
Comparative Example 4
The same procedure as in Example 1 was repeated, except that the 2,6-di-tert-butyl-4-methylphenol was not used to prepare a photoreceptor.
Comparative Example 5
The same procedure as in Example 1 was repeated, except that N-phenyl-1-naphthylamine as an amine type antioxidant was substituted for the 2,6-di-tert-butyl-4-methylphenol in the same amount as the latter to prepare a photoreceptor.
Comparative Example 6
The same procedure as in Example 1 was repeated, except that p-tert-butylphenol salicylate as a salicylic acid type photostabilizer was substituted for the 2,6-di-tert-butyl-4-methylphenol in the same amount as the latter to prepare a photoreceptor.
Comparative Example 7
The same procedure as in Example 1 was repeated, except that 2-hydroxy-4-methoxybenzophenone as a benzophenone type photostabilizer was substituted for the 2,6-di-tert-butyl-4-methylphenol in the same amount as the latter to prepare a photoreceptor.
Comparative Example 8
The same procedure as in Example 1 was repeated, except that an X type metal-free phthalocyanine was substituted for the hydroxytitanium phthalocyanine to prepare a photoreceptor.
The electrophotographic characteristics of the electrophotographic photoreceptors obtained in Examples 1 and 2 and Comparative Examples of 1 to 8 were evaluated by means of a conventional electrophotographic photo-receptor evaluation apparatus. The above photo-receptor was charged at an applied potential of -5 KV, the surface potential V 0 was measured, and the photoreceptor was allowed to stand in the dark for 10 seconds, and then exposed to semiconductor laser (λ=78 nm, exposure: 2 erg/cm 2 ), after which the exposure necessary for damping the surface potential to 1/2 (half-damped exposure) was calculated.
The surface potential, half-damped exposure, dark damping factors, charge potentials, residual potentials and response time determined in the above-mentioned manner are shown in Table 1.
TABLE 1______________________________________ V.sub.0 F.sub.f0 V.sub.01 (V) (μJ/cm.sup.2) DDR.sub.1 (V)______________________________________Example 1 720 0.1 0.90 720Example 2 700 0.1 0.90 700Comp. Ex. 1 700 0.3 0.90 700Comp. Ex. 2 700 0.2 0.90 700Comp. Ex. 3 650 0.1 0.80 700Comp. Ex. 4 620 0.1 0.82 700Comp. Ex. 5 720 0.1 0.90 720Comp. Ex. 6 720 0.1 0.90 720Comp. Ex. 7 720 0.1 0.90 720Comp. Ex. 8 720 0.3 0.90 720______________________________________ Note: V.sub.0 : Surface potential (at an applied voltage of -5 KV) E.sub.f0 : Halfdamped exposure (650 KV, 780 nm) DDR.sub.1 : Dark damping factor (initial, for 10 sec) DDR.sub.2 : Dark damping factor (after 200 cycles, for 10 sec) V.sub.01 : Initial charge potential V.sub.02 : Charge potential after 200 cycles V.sub.R1 : Initial residual potential V.sub.R2 : Residual potential after 200 cycles Response time: Lightresponse time of charge
ResponseV.sub.R1 V.sub.02 V.sub.R2 time(V) (V) (V) DDR.sub.2 (sec)______________________________________10 720 10 0.88 0.110 700 10 0.85 0.150 690 50 0.85 0.340 690 40 0.85 0.310 650 10 0.75 0.1510 670 10 0.77 0.125 720 30 0.88 0.1530 720 30 0.90 0.1530 720 30 0.90 0.1530 720 30 0.85 0.1______________________________________
As is clear from Table 1, when 1-p-dibenzyl-aminophenyl-1-p-diethylaminophenyl-4,4-diphenyl-1,3-butadiene was used as the charge-transfer material, the residual potential was particularly low, and the response time was short. Comparative Example 3 is good in residual potential but inferior in chargeability and dark damping factor. Comparative Example 4 is the case where 2,6-di-tert-butyl-4-methylphenol was not added, in which the chargeability was inferior. With other additives, the chargeability is enhanced, but the residual potential becomes high, and also the response time becomes significantly longer. Comparative Example 8 is the case of using metal-free phthalocyanine, and in this case, the sensitivity was bad.
Thus, this invention has a superior effect and is very useful.
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An electrophotographic photoreceptor which is highly sensitive to light having a wavelength in the oscillatory wavelength region of semiconductor laser and responds quickly and is excellent in other electrophotographic characteristics and which consists an electroconductive support, a charge-generating layer and a charge-transfer layer, the two layers being placed on the support, and said charge-transfer layer containing a specific butadiene compound having formula (I); ##STR1## and a monophenol type antioxidant, the weight ratio of the monophenol type antioxidant/the butadiene compound ranging from 5/95 to 40/80.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
Needlepoint, in the present day sense of the word, includes all kinds of embroidery done on canvas, varieties being known as quickpoint; grospoint; petitpoint; Bargello, also known as Florentine, flame or Hungarian embroidery; and other repeat patterns. The coarseness of the canvas base varies from, for example, 3 threads to 7 threads to the inch in quickpoint to more than 20 threads to the inch in petitpoint.
The present invention relates to a novel method of copying selected patterns in needlepoint which avoids the difficulties inherent in the methods previously known and used.
2. Description of the Prior Art
Needlework is an ancient art, specimens having been found in Egyptian tombs dating back to the 15th century B.C. Needlepoint came into its own in China during the 12th century A.C. and presently is enjoying a revival following a decline attributed to the advent of machinery.
In needlepoint, the commonest practice is to copy the desired pattern by counting stitches and background threads, selecting appropriate kinds of stitches from a wide variety of known variations. Publications such as "Needlepoint by Design" by Lane, published by Charles Scribner's Sons, New York, 1970, and "The New World of Needlepoint" by Perrone, published by Random House, Inc., New York, 1972, describe known methods of needlepointing from photographs and charts, or graphs, of various patterns.
Previous efforts to avoid the necessity of counting stitches in the course of such work have involved adhering pattern sheets to the cloth to be decorated and stitching the delineated pattern through such sheets and the material, as in Rick et al. U.S. Pat. No. 2,756,434.
A need has existed, however, for a method and equipment meeting the special requirements of needlepoints for accurate placement of the required lengths and kinds of stitches required for the formation of pattern repeats positioned in a desired relationship to each other and to an overall design, and it is the object of the present invention to meet that need.
SUMMARY OF THE INVENTION
A needlepoint project consists essentially of the application of a variety of variously colored patterns to a canvas sheet on which a design has been delineated. This design comprises an outlined area or areas intended to be decorated by one or more patterns.
According to the present invention, at least two delineations of a pattern, called a "pattern repeat" are transferred from a source, such as a pattern card bearing cross-hatching congruent with the threads of the canvas to which the pattern is to be applied, to a pattern guide in the form of a congruently cross-hatched transparent sheet. This is done by overlaying the pattern guide on the pattern card, with their cross-hatchings in congruence, and tracing the pattern repeat onto the upper surface of the pattern guide. Preferably, this is done using a water-soluble film pen so that the tracings on the pattern guide may be erased and the guide reused.
The pattern guide bearing the copied pattern repeat is then laid upon the canvas and may be moved about freely to see exactly what the pattern will look like in various positions within the outlined area of the design in which it is to be reproduced.
When the pattern has been positioned approximately as desired, the horizontal and vertical lines of the pattern guide are superimposed upon the nearest horizontal and vertical threads of the underlying canvas, and a threaded needle is positioned from the back of the canvas in a selected hole at an edge of one of the pattern repeats. Removing the pattern guide, the needle is then pulled to the front of the canvas and the first stitch, of the length shown on the pattern guide, is completed. Following this, the remaining stitches required to complete application of the pattern repeat to the canvas are completed using the original chart for directions, if necessary, and the pattern guide for stitch placement.
Subsequent placements of additional repeats of the same pattern within the same design are effected by replacing the pattern guide so that one pattern delineation overlies one stitched on the canvas and another overlies an unstitched area, with the horizontal and vertical lines of the pattern guide overlying the canvas threads as before. A starting hole for an additional one of the pattern delineations is then located in the same manner as was the starting hole for the first one, and the additional pattern delineation is completed in the same way.
When the first pattern has been applied as many times as desired, the pattern guide is wiped with a damp cloth to erase the pattern repeat tracing from its surface. A second pattern repeat then may be traced onto the pattern guide and applied to the canvas just as was the first.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a simple pattern;
FIG. 2 is an illustration of a more complex pattern;
FIG. 3 is an illustration of a pattern card for the application of a pattern such as that of FIG. 1;
FIGS. 4a, 4b and 4c are illustrations of a pattern card for the application of a pattern such as that of FIG. 2;
FIG. 5 is an illustration of a transparent pattern guide employed in carrying out the present invention;
FIG. 6 is an illustration showing the technique of locating the starting hole for a pattern stitch in the canvas with the pattern guide overlaid;
FIG. 7 is an illustration showing how the first stitch is completed after removal of the pattern guide; and
FIG. 8 is an illustration showing the technique of locating the starting hole for a second identical pattern in correct juxtaposition with a completed one.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the application of the method of the present invention, pattern cards are employed on which is delineated, first, a background grid the mesh size of which is the same as the mesh size of the canvas to which the pattern is to be transferred and, second, superimposed lines indicating where each stitch of the pattern repeat begins and ends; how long each stitch is in relation to the number of canvas threads (not holes) it crosses over; how many stitches are in each pattern repeat and the direction in which they are worked; i.e., horizontally, vertically or diagonally. If all pattern repeats are stitched the same, no matter in what color or colors, only one repetition of the pattern is diagrammed on the pattern card and successive repetitions of it are properly located as hereinafter described.
For example, as shown in FIG. 1, the pattern repeat 10 consists of a first delineation of the pattern consisting of area a and area b; a second delineation of the same pattern consisting of area a' and area b' and a third area c which is unnecessary in the case of certain types of patterns but desirable for orientation of adjacent repeats in the case of this pattern.
A pattern card 12 (FIG. 3) has delineated thereon a background grid 13 of the same mesh size as the canvas to which the pattern is to be applied, and superimposed thereon are lines 15 indicating where each stitch of the pattern begins and ends; how long each stitch is in relation to the number of canvas threads (corresponding to the lines of grid 13) it crosses over; how many stitches are in each pattern repeat; and the direction in which they are worked.
The delineation of the stitches appearing on the pattern cards is the same for all types of stitches, leaving the user free to choose any of the various types of stitches; e.g., Continental, Scotch, Florentine, etc. in applying the pattern to the fabric.
In applying such a pattern to a fabric base such as a canvas, a template in the form of a pattern guide 17 (FIG. 5) is employed. This is a sheet of transparent material, such as acetate, which has delineated thereon a grid 18 of the same mesh size as the grid 13 although larger in its longitudinal and vertical dimensions. With the pattern guide 17 laid over the pattern card 12 and the grids 13 and 18 congruent, the stitch lines 15 are traced on the upper surface of the pattern guide 17, preferably using a water soluble film pen so that the tracings may be washed off when the pattern guide is to be reused for a different pattern.
The pattern guide 17 is then laid upon the canvas to which the pattern is to be transferred, on which the outline of the design has been delineated as indicated at 19 in FIGS. 6, 7 and 8. With the grid 18 congruent with the threads of the canvas and the traced stitch lines positioned over the area to which the pattern is to be applied, a threaded needle is passed from the underside of the canvas through the canvas hole underlying the end of a stitch line trace overlaid by the traced pattern. The pattern guide then is removed, the first stitch is completed, and the remaining stitches of the traced pattern are applied, referring to the traced pattern for the stitch lengths and relative orientation.
For extensions of the application of the same pattern to a larger area it is necessary only to align a portion of the tracings on the pattern guide 17 with a portion of the already stitched pattern on the canvas in the desired offset relation therewith, and to apply as many whole or partial repeats of the pattern as necessary to fill the allocated area.
The manner in which this is accomplished is illustrated in FIGS. 6, 7 and 8 showing the application of a simple triad of asterisks design. In FIG. 6, with the pattern guide 17 overlying the canvas on which the outlines of the design are delineated, as at 19, the starting hole indicated by the arrow 21 is located and the needle is positioned in it from the back of the canvas. The pattern guide is then removed and the needle is pulled to the front of the canvas, as shown in FIG. 7. Referring to the pattern card 12 for stitch lengths and orientation, the first repeat of the pattern then is completed.
To locate subsequent repeats of the same pattern, the pattern guide, carrying the pattern traced on it, is replaced over the pattern area, as shown in FIG. 8, with its grid congruent with the threads of the canvas and one group of traced stitches 22 of the pattern overlying and in alignment with a repeat already stitched into the canvas; the remaining traced stitches 23 overlying an unstitched area to which the pattern is to be extended. The additional repeats of the pattern are then applied in the same way as those first applied.
If each pattern component involves the use of a different pattern stitch, whether or not different colors are to be used, then each is diagrammed separately. For example, for transfer of the pattern of FIG. 2 which is to be reproduced in three different colors, each stitched differently, the pattern card diagrams of FIGS. 4a, 4b and 4c are provided. After one of these pattern elements such as 25 has been stitched into the canvas in the selected area or areas of the whole design, a second one, such as 26, is traced onto the pattern card 12, aligned in its proper relationship with that already stitched, and stitched into the canvas. The last pattern elements 27 and 28 then are traced, positioned and stitched in the same way.
In the course of transferring patterns by this method, the traced diagram may be moved around freely to see exactly what the pattern will look like in any given area. Guessing as to whether the pattern will or will not fit in a selected area thus is eliminated. Checking for accuracy of stitch placement is simplified; it being effected by merely overlaying the pattern guide trace on a stitched area.
At edges 19 of the design outline where full stitches cannot be taken, guess work is eliminated because, by positioning the pattern guide trace at an edge 19, the exact length and location of each partial stitch is clearly indicated.
With the foregoing description of the preferred ways of carrying out the method of the present invention, its essential features and advantages will be readily understood by those familiar with the needleworking art, and changes in the details of application of the method may, of course, be resorted to within the scope of the following claims.
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Patterns to be applied to a needlepoint design outlined on a canvas panel are first traced in stitch-length markings on a grid of the same mesh size as the canvas mesh size, delineated on a transparent sheet. This sheet is then laid over the canvas panel with its grid aligned with the threads of the panel and the pattern in the desired position thereon. Threads are then embroidered into the panel in alignment with traced pattern. Spacing of repeats of the pattern is effected by tracing at least two delineations of the pattern on the transparent sheet in their intended spacing.
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FIELD OF THE INVENTION
[0001] The present invention is broadly directed to tour guidance systems. More specifically, the present invention is directed to a system for location based narration using GPS data and incorporating spatial and non-spatial elements to create intelligent, adaptive and dynamically mixed touring-type programs.
BACKGROUND TO THE INVENTION
[0002] Recent years have seen the advent of GPS technologies for determining the location of devices within which tour based technologies have been embedded.
[0003] These are small, inexpensive and low power devices, and have been put to many commercial uses including GPS based navigation systems, and more recently, systems that provide audio commentary triggered by GPS location.
[0004] The current breed of such systems are typically targeted at automated touring systems for providing commentary on points of interest to tourists.
[0005] These tours may be in the field of sightseeing, where the content of the tour primarily relates to the immediate visual landscape or is of local interest. These tours may also serve specific niche purposes in other industry segments. This may include car launches, driver training programs or car orientation programmes, where the tour content also pertains to relevant features of the car as it responds to the changing road characteristics.
[0006] Although existing systems may be suitable for providing limited information to tourists, a number of novel features are required to support actual tours, especially multi-day tours and tours that have a natural flow, as well as supporting a range of tour planning requirements.
[0007] Furthermore, tourists often want more than just “information” associated with their GPS location. They frequently want a personalised and contextualised story, based on a pre-planned, yet adaptive schedule and delivered in real-time.
[0008] Known prior art systems typically simply trigger audio content when the current GPS coordinates are within a certain proximity to predefined coordinates. Some such systems appear to also take direction into account so that different audio can be played depending on the direction of travel. This is important when narration includes such phrases as “on your left . . . ” or “on your right . . . ”.
[0009] While existing GPS commentary systems can respond to location, there is currently no known application that delivers personalisation. Broadly speaking, existing systems are limited or deficient in the following respects. Existing systems do not typically:
provide a GPS guided audio tour based on pre-developed content for predefined routes, by selecting, mixing and playing back pre-recorded audio at predefined positions along the route; incorporate non-spatial elements, including factors such as date and time, and where the user has already been; use tour route concept to support functionality, such as off tour detection, return-to-tour music recommencement, and dynamic/predictive music mixing; use a combination of spatial and non-spatial characteristics to facilitate the intelligent choice of audio selection given varying speed parameters of the running of each tour; dynamically mix narration and music together in real-time or apply predictive fading to seamlessly fade the music volume levels and thereby improve the listening experience; integrate standard Travel Navigation Software to permit spoken turn by turn instructions for arbitrary use by the traveler, or to return the traveler to the tour; or integrate adaptive tour scheduler that continually compares the current time of day against the scheduled itinerary, and makes intelligent recommendations if, for example, the tour is running late.
[0017] The present invention seeks to overcome and/or ameliorate one or more of the above limitations or deficiencies.
SUMMARY OF INVENTION
[0018] In a first aspect, the present invention provides a tour guidance system adapted to selectively deliver pre-recorded media data to a user, the tour guidance system comprising:
[0019] position identification means for determining positional data concerning the user;
[0020] data storage means adapted to store tour route data, tour point data, and media data associated with at least one tour route and/or at least one tour point;
[0021] processing means adapted to process the tour route data and/or the tour point data and selectively determine the delivery of at least a first segment of media data relevant to the user's position, the determination based on an algorithm adapted to prioritise the delivery of one or more of a plurality of segments of media data with reference to at least a predetermined tour point priority parameter; and
[0022] media delivery means adapted to deliver one or more of the plurality of segments of media data selected by the processing means.
[0023] Each segment of media data preferably has at least one media content and is in at least one media form. The media content may be selected from narration, musical score, song, or video. In a particularly preferred embodiment, the media content is selected from narration and musical score or song. The media form may be selected from narration, audio or video. In a particularly preferred embodiment, the media form is audio.
[0024] Preferably, the tour point data includes at least one tour point type. Preferable tour point types include:
[0025] Navigation type tour points. These typically represent a particular position within a tour route and indicate that the system is to deliver media data in narration media form and having media content that provides geographical directions to a user of the system;
[0026] Narration type tour points. These typically represent a particular position within a tour route and indicate that the system is to deliver media data in narration media form and having media content of general interest or of relevance to the user's position;
[0027] Stop type tour points. These typically represent a particular position within a tour route and indicate to the system a location where a user can arrive (which is on or within the tour route) at which it is likely to remain and possibly move around (without going off route) for a period of time. Accordingly, stop type tour points typically also include a stop zone region and a minimum stop time duration. The stop zone region is a geographic region surrounding the tour point. Travel anywhere within the stop zone region will not be considered by the system to be off tour. If the user stays within the stop zone region for at least the minimum stop time duration, the system will flag that the user has stopped at the relevant stop type tour point. At a stop type tour point the typical media data that is delivered may be in narration media form and/or music media form; and
[0028] Music type tour points. These typically represent a particular position within a tour route and indicate that the system is to deliver media data in audio form and having media content of a musical score or song.
[0029] More than one of a navigation type tour point, a narration type tour point, a music type tour point and a stop type tour point may be encountered by the system substantially simultaneously or within substantially the same vicinity. The processing means applies the algorithm to selectively determine which one or more of the plurality of media segments should be delivered by the media delivery means and in what order media segments should be delivered.
[0030] According to the algorithm, the system is adapted so that it can deliver a segment of music media data simultaneously with a segment of media data associated with a navigation type tour point, a narration type tour point or a stop type tour point.
[0031] Preferably, a segment of media data having narration media form and a segment of media data having music media form are delivered simultaneously. To achieve this capability, the media delivery means of preferred embodiments has at least two media delivery channels. Each media channel is adapted to deliver media data with at least one media form (and at least one media content). In a particularly preferred embodiment, the media delivery means includes a narration delivery channel and a music delivery channel. The media delivery means may also include a video delivery channel.
[0032] Also, according the algorithm, the system is adapted so that it can deliver several segment of media data in a predetermined order.
[0033] The tour point priority parameters are used by the algorithm to make determinations regarding which segment or segments of media data are to be delivered at any one time. Preferably, the tour point priority parameters are prioritised using Boolean settings. The parameters preferably attribute a higher priority to navigation type tour points over that attributed to narration type tour points and stop type tour points, which are attributed substantially equal priority to one another.
[0034] Accordingly, if the position identification means determines that the system is adjacent to, or has passed, a navigation type tour point, the application of the algorithm results in the relevant media data for that navigation type tour point to be delivered irrespective of, and in substitution for, any other media data relevant to an adjacent narration type tour point or stop type tour point that may be being delivered by the system at that time.
[0035] In some such embodiments, once the segment of media data delivered for the relevant navigation tour point has completed being delivered, the remainder of the segment of media data associated with the narration type tour point or stop type tour point that was previously being delivered may continue to be delivered. Alternatively, depending on the position of the user, the algorithm may determine that the remainder of that segment of media data should not be delivered.
[0036] In another preferred embodiment, the algorithm prioritises the delivery of one or more of a plurality of segments of media data with further reference to at least one location specificity parameter. Preferred location specificity parameters include:
[0037] Location specific points. These typically represent a characteristic of a tour point and are an indication to the system that a particular segment of media data relevant to the current tour point is delivered at this specific position or is inhibited from being delivered;
[0038] Floating points. These typically represent a characteristic of a tour point and are an indication to the system that a particular segment of media data relevant to the current tour point is general in nature, its order in the narrative is important, and it is relevant to be delivered regardless of the user's specific location; and
[0039] Nudge points. These typically represent a characteristic of a tour point and are an indication to the system that a particular segment of media data relevant to the current tour point is relevant to a particular region starting at the location of the tour point, and finishing at a predetermined location on the tour route specified by an end nudge zone marker.
[0040] In preferred embodiments, depending on the location specificity parameter and the tour point priority parameter, when a tour point is encountered whilst a particular segment of media data is already being delivered on a particular audio channel, application of the algorithm can determine any one of a number of alternatives including:
[0041] Inhibit delivery of the segment of media data that is currently being delivered on that channel, and selectively deliver a different segment of media data;
[0042] Continue delivery of the segment of media data currently being delivered on that channel, and inhibit delivery of a different segment of media data that the system would otherwise cause to be delivered; and
[0043] Queue the delivery of a different segment of media data than is currently being delivered. When the segment of media data that is currently being delivered completes, application of the algorithm can then determine, based on the user's position, whether the queued segment of media data is delivered or not. Preferably, such queuing is applied according to first in first out principles.
[0044] In other preferred embodiments, the algorithm further utilises non-spatial data including the current date and time and data relating to where the system has already been within or outside a particular tour route or tour routes in making determinations as to which of one or more of a plurality of segments of media data to be delivered at any given time,
[0045] A tour route of preferred embodiments includes at least one path option for a user to take. Paths can join to one or more other paths, preferably in a directed manner, where a path represents an optional part of the tour. Each path consists of at least one line segment, a line segment defined by route points at either end. Where a path consists of multiple line segments, adjoining line segments share a route point.
[0046] Each route point is preferably defined by a longitude and latitude. The system preferably uses the positional data determined by the position identification means and the tour route data to identify the location of the user on a particular tour route.
[0047] In some preferred embodiments, each route point is also associated with a predetermined nominal tour point arrival time which represents the time at which a nominal user might arrive at that particular route point from when it started travelling along the corresponding path option. The nominal tour point arrival time is used, in some preferred embodiments, to calculate a nominal position within a segment of media data from which that segment of media data should be delivered. In one embodiment, the nominal tour point arrival time is used when the user is returning to a tour route after having been off route.
[0048] In yet still further preferred embodiments, the system further utilises tour state data in determining which segment of media data to deliver. Preferably, the tour state includes a list of tour points types that have been passed. This list is emptied when the tour is started, and is updated by the system as the user travels within a tour route.
[0049] Preferably, the system selectively determines which of a subset of segments of media data related to a particular tour point should be delivered based on the tour state data. In one preferred embodiment, the subset of segments of media data include
[0050] a segment containing data appropriate for when the user already passed the relevant tour point;
[0051] a segment containing data appropriate for when the user will pass that tour point some time in the future; and
[0052] a segment containing data appropriate for the season in which the tour route is being taken.
[0053] In some such preferred embodiments, the system uses conditions to determine which segment of media data to deliver. The conditions may include:
[0054] Passed Tour Point Conditions. These specify to the system to check whether the user has actually passed a specific tour point;
[0055] Stop Point Dependent Conditions. These specify to the system to check whether the user passed a particular tour point, and remained in the vicinity of that tour point for a minimum duration;
[0056] Time Dependent Conditions. These typically specify to the system to check the current time at which the user has arrived at a particular tour point;
[0057] Date Dependent Conditions. These typically specify to the system to check the current date on which the user is taking the tour route;
[0058] Attraction Opening Times Dependent Conditions. These typically specify to the system to check an attraction opening times database containing information regarding facility opening times. Conditions based on attraction opening times can also be date and/or time relative. Preferably, the attraction opening times database identifies each attraction by name, and includes a list of opening times. The opening times can be specified differently based on day of week or day of month, and can also include exception cases;
[0059] Tour Scheduler Dependent Conditions. These typically specify to the system to check tour scheduler data containing information regarding tour activities. Tour scheduler data can be used to assist the user to complete the relevant tour by a specific time. In one preferred embodiment, the tour scheduler data dependant condition is used to deliver media data advising the user not to travel to an attraction if, based on the current time and travel at average speeds, the attraction is unlikely to be open when the user would arrive at that attraction; and
[0060] Speed Dependent Conditions. These typically specify to the system to check the current travel speed;
[0061] Acceleration Dependent Conditions. These typically specify to the system to check the current speed relative to the speed at a previously nominated time.
[0062] In further preferred embodiments, the system also uses expressions to address complex circumstances. Preferably, an expression combines a condition. Expressions can include:
[0063] A Boolean condition:
[0064] The logical inverse of Expression 1;
[0065] The logical conjunction of Expression 1 with Expression 2;
[0066] The logical disjunction of Expression 1 with Expression 2; and
[0067] A named expression. Named expressions are used in a plurality of locations.
[0068] One or more of the conditions and/or expressions can be used in varying embodiments of the invention.
[0069] In a second aspect, the present invention provides a logic unit adapted for integration with the tour guidance system of the first aspect of the invention, the logic unit adapted to dynamically mix at least two segments of media data being delivered to a user of the tour guidance system, said logic unit comprising:
[0070] predicted position determining means adapted to predict the likely position, relative to the tour route, at which the user will arrive in a predetermined time interval;
[0071] tour point determining means adapted to determine whether there is one or more tour points between a previously determined predicted position and the predicted likely position; and
[0072] altering means adapted, depending on the presence of at least one tour point between the previously determined predicted position and the predicted likely position, to selectively alter a first property of a first segment of media data and/or a second property of at least a second segment of media data,
said alteration made with reference to the tour point type of the one or more tour points between the previously determined predicted position and the predicted likely position and the type of media data being delivered when the predicted likely position is determined.
[0074] In a preferred embodiment, the predicted position determining means further comprises:
[0075] direction identification means adapted to determine the direction in which the user is travelling relative to the tour route; and
[0076] speed determining means adapted to determine the approximate average speed at which the user is travelling.
[0077] The direction identification means preferably determines the direction in which the user is travelling by reference to a determined position of the user on the tour route relative to the position data provided by the position determining means.
[0078] The speed determining means preferably determines the approximate average speed at which the user is travelling by dividing the distance between at least two position data parameters provided by the position determining means by the time it took for the user to travel between those two position data parameters.
[0079] The logic unit preferably determines the predicted likely position using the direction in which and the speed at which the user is travelling by determining where, relative to the tour route, the user is likely to be in a predetermined time interval. In one preferred embodiment, the predetermined time interval is between 2 and 8 seconds, and in particularly preferred embodiments the predetermined time interval is 3 seconds. However, in alternative embodiments, the predetermined time interval may be of any duration.
[0080] In preferred embodiments, if the tour point determining means determines there is at least one tour point between the previously determined predicted position and the predicted likely position, the logic unit assesses the tour point data to determine the tour point type. The logic unit also determines whether a first segment of media data is currently being delivered by the tour guidance system.
[0081] Preferably, the first media segment is in narration or audio media form and has narration or music score or song media content. The second media segment is in narration or audio media form and has narration or music score or song media content.
[0082] In such preferred embodiments, the first and second properties altered by the altering means are the volumes of the respective segments of media data.
[0083] In an alternative embodiment, the first and/or second segment of media data is in video form. In such embodiments, the corresponding property altered by the altering means is brightness of the relevant segment of media data.
[0084] In a third aspect, the present invention provides a method of providing tour guidance to a user in accordance with position data, comprising:
[0085] storing tour point data for a plurality of tour points to be visited by a user in a tour, the tour point data including:
information regarding the location of at least one tour point; a segment of media data relevant to at least one tour point; and a priority parameter associated with at least one tour point;
[0089] determining position data relevant to the position of the user during a tour; and
[0090] in accordance with the position data determining that the user is adjacent a tour point, selectively delivering to the user a first segment of stored media data relevant to that tour point in accordance with the priority parameter.
[0091] Preferably, the tour point data stored in the method of the second aspect includes:
information regarding the location of each tour point; a segment of media data relevant to each tour point; and a priority parameter associated with each tour point.
[0095] The selective delivery of the stored media data may take place in accordance with a determination of whether a second segment of stored media data is currently being delivered to the user.
[0096] The priority parameter may be used to determine a selection from the group of:
[0097] discontinuing delivery of the second segment of stored media data to the user in preference to delivery of the first segment of stored media data;
[0098] continuing delivery of the second segment of stored media data and not delivering to the user said first segment of stored media data;
[0099] continuing delivery of the second segment of stored media data until completion, and then selectively delivering the first segment of stored media data to the user; and
[0100] queuing delivery of the second segment at least until completion of delivery of the first segment of media data, and then determining, based on the position data, whether the queued segment of media data is delivered or not.
[0101] The tour point data may include a location specificity parameter, and the selective delivery of the stored media data for that tour point may take place in accordance with a determination based on the specificity parameter. Preferred location specificity parameters include Location specific points, Floating points and Nudge points as described above with reference to the system of the first aspect of the invention.
[0102] In other preferred embodiments, the method further utilises non-spatial data including the current date and time and data relating to where the position data indicates the user has already been within or outside a particular tour route or tour routes in making determinations as to which of one or more of a plurality of segments of media data to be delivered at any given time,
[0103] The method may include the step of, in accordance with the specificity parameter, only delivering the first segment of stored media data relevant to a tour point on determination that the user is within a prescribed distance of that tour point.
[0104] The segment of media data may be an audio file selected from the group of:
[0105] a narration providing information to the user concerning a site or object at or near to the tour point or be of general relevance to the tour;
[0106] a music segment selected in accordance with the tour point; and
[0107] a navigation instruction providing directions to the user.
[0108] Preferably, the method also includes the step of referring to predetermined Boolean settings to determine the priority of media data to be delivered. Preferably, when selecting the segment of media data to be delivered, a higher priority is attributed to navigation instructions than to narration.
[0109] One preferred embodiment of the method of the third aspect includes the step of delivering navigation instructions and narration through a first media delivery channel and delivering the music segment through a second media segment. Preferably, the method also includes the step of delivering the music segment simultaneously with a narration or navigation instruction.
[0110] In a fourth aspect, the present invention provides a media mixing method for dynamically mixing at least two segments of media data being delivered according to the method of the third aspect of the invention, said media mixing method comprising:
[0111] predicting the likely position, relative to the tour, at which the user will arrive in a predetermined time interval;
[0112] determining whether there is one or more tour points between a previously determined predicted position and the predicted likely position; and
[0113] depending on the presence of at least one tour point between the previously determined predicted position and the predicted likely position, selectively altering a first property of a first segment of media data and/or a second property of at least a second segment of media data,
said alteration made with reference to the tour point data of the one or more tour points between the previously determined predicted position and the predicted likely position and a type of media data being delivered when the predicted likely position is determined.
[0115] In a preferred embodiment, the step of determining the predicted likely position includes:
[0116] determining the direction in which the user is travelling relative to the tour route; and
[0117] determining the approximate average speed at which the user is travelling.
[0118] The direction in which the user is travelling is preferably determined by reference to a determined position of the user on the tour relative to the position data.
[0119] The speed at which the user is travelling is preferably determined by dividing the distance between at least two position data parameters by the time it took for the user to travel between those two position data parameters.
[0120] The predicted likely position is preferably determined using the direction in which and the approximate average speed at which the user is travelling and determining where, relative to the tour, the user is likely to be in a predetermined time interval. In one preferred embodiment, the predetermined time interval is between 2 and 8 seconds, and in particularly preferred embodiments the predetermined time interval is 3 seconds. However, in alternative embodiments, the predetermined time interval may be of any duration.
[0121] In another preferred embodiment, the media mixing method further comprises determining whether a first segment of media data is currently being delivered by the tour guidance system.
[0122] Preferably, the first media segment is music or narration and the second media segment is music or narration. In such preferred embodiments, the first and second properties altered by the altering means are the volumes of the respective segments of media data.
[0123] Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
[0124] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention before the priority date of the patent application filed with this specification.
[0125] In order that the present invention may be more clearly understood, preferred embodiments will be described with reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0126] FIG. 1 is a block diagram illustrating the hardware components of a preferred embodiment of the system of the present invention;
[0127] FIG. 2 is a block diagram illustrating an example of a tour data structure for a tour route according to a preferred embodiment of the present invention;
[0128] FIG. 3 is a simple illustration of a tour route comprising a single path, representing an example of the kind of information stored within the tour route data structure of preferred embodiments;
[0129] FIG. 4 is a further example of a tour route, having multiple paths, and therefore providing ‘path options’ for a particular tour of a preferred embodiment of the present invention;
[0130] FIG. 5 is a table listing the path connections of the example tour routing FIG. 4 ;
[0131] FIG. 6 is a simplified line diagram illustrating how the system of a preferred embodiment of the present invention determines how the position of a tour point is specified with reference to a line segment and route point;
[0132] FIG. 7 provides a simple line diagram of a tour route;
[0133] FIG. 8 is a flow diagram illustrating the manner in which a preferred embodiment of the system determines the current position of a tourist on a tour route and commences the process for playing relevant audio to the tourist;
[0134] FIG. 9 is a flow diagram illustrating how the system of a preferred embodiment responds to a tour point having been passed;
[0135] FIG. 10 is a flow diagram illustrating how the system of a preferred embodiment determines when the audio for a specified tour point should be played;
[0136] FIG. 11 is a flow diagram illustrating how the system of a preferred embodiment responds when a music file completes playing;
[0137] FIG. 12 is a flow diagram illustrating how the system of a preferred embodiment responds when a narration file completes playing;
[0138] FIG. 13 is a flow diagram illustrating how the system of a preferred embodiment initiates playing the audio associated with a specific tour point;
[0139] FIG. 14 is a flow diagram illustrating the manner in which the system of a preferred embodiment incorporates predictive fading for music as a traveller progresses along a specific tour route;
[0140] FIG. 15 is a flow diagram illustrating how the system of a preferred embodiment evaluates a Tour Point Conditional Expression;
[0141] FIG. 16 is a flow diagram illustrating how the system of a preferred embodiment determines the initial positions list;
[0142] FIG. 17 is a flow diagram illustrating how the system of a preferred embodiment finds forward moving positions from the initial positions list;
[0143] FIG. 18 is a flow diagram illustrating how the system of a preferred embodiment selects the initial deemed position from the initial positions list;
[0144] FIG. 19 is a flow diagram illustrating how the system of a preferred embodiment determines the deemed position along the route given coordinates;
[0145] FIG. 20 is a flow diagram illustrating how the system of a preferred embodiment plays music as the traveller enters the tour route
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0146] Preferred embodiments of the system of the present invention provide a pre-defined guided tour to a user of the system by running a computer software program that selects, mixes and plays back pre-recorded audio. This tour responds dynamically to the user's state, which in turn depends on its GPS location and direction, as well as other factors, such as, where the user has been and the time and date of the tour. Preferred embodiments of the invention therefore incorporate non-spatial elements to deliver an intelligent and adaptive experience, that is dynamically mixed.
[0147] In preparing the data for presentation during a tour, ‘content developers’ initially record GPS information and audio data during the course of tour development. Interviews may be performed live in the field, with positional information retained. In this manner, knowledge of where any portion of the particular audio data was recorded is available for later access by the ‘content developer’. The ‘content developer’ may then create a tour ‘project file’, for example, in the format of ‘.hhp’, ‘.xml’ or any other preferable format. The project file specifies such items as the route that the tour should take and where the various portions of audio should be played.
[0148] The system of the present invention uses spatial and non-spatial data to appropriately deliver the project file for that route to the end user.
[0149] The system can execute on a number of different hardware platforms that meet the minimum requirements for processor speed, memory availability and audio output, as well as a GPS receiver. Suitable hardware includes, for example, a PDA with an inbuilt GPS receiver, a PDA with access to an external GPS receiver, or an infotainment/GPS navigation system currently found in higher end automobiles.
[0150] FIG. 1 shows a block diagram of the hardware components of the system. The CPU subsystem 1 , include RAM/ROM, timers and a real-time clock, and runs a suitable off-the-shelf operating system, such as Windows Mobile, and a software program adapted to execute the system of the present invention.
[0151] The system includes hardware 2 for visually displaying information to the user, as well as receiving various selections from the user. A touchscreen provides a very simple and easy to use way for user interaction.
[0152] The GPS receiver 3 is a readily available off-the-shelf component for receiving radio signals from GPS satellites and processing them in such a way as to provide a regular indication of the current location in terms of longitude and latitude on the earth.
[0153] The system includes non-volatile storage 4 for storing the software program adapted to execute the system of the present invention, as well as state information as the tour progresses. Although some program state may be held in RAM, state changes of significant events are stored in non-volatile memory, so that it will be available if, for example, the system is rebooted.
[0154] The tour content is preferably stored on non-volatile media 5 , such as an SD Card, CD or DVD-ROM, or on a hard disk, for example.
[0155] The audio reproduction hardware 6 takes the digital information from the CPU and converts this into an analogue audio signal suitable for connection to, for example, audio headphones, a miniature FM transmitter, or other such device.
Tour Route Concept
[0156] The system of preferred embodiments includes the concept of a “tour route” as an integral part of the data structures within the tour project file.
Among other things, the tour route concept preferably enables the following: Detection of when the user has come off the tour. This allows the application to give the user audio feedback, and options for returning to the tour. Support for tours that go in both directions along a road or involve multiple passes along the same stretch of road. Supporting multiple passes is useful for tours through the centre of a town where the tour might branch out into different directions. Support for dynamic/predictive music mixing as described below. Support for return to tour music recommencement, as described below.
[0162] Some of these features, rely not only on a tour route, but also a nominal speed associated with each portion of the route.
Data Structures
[0163] The invention makes use of a number of different data structures. Some of these data structures pertain to a tour project file, that specifies all aspects of a tour. Some data structures are used for internal processing whilst a tour is in progress.
Tour Data Structure
[0164] A tour data structure 101 is a data structure that contains information regarding the entire tour. This is shown in FIG. 2 , and comprises:
1. A data structure that contains the entire tour route 102 . 2. A data structure consisting of multiple tour points 103 . 3. Reference to a file containing the Attractions Opening Times information 104 . This file consists of a database of zero or more Attraction Opening Entries.
[0168] This is loaded from non-volatile memory into RAM when a particular tour is selected by the user.
4. Zero or more named expressions, also referred to as the named expression list 105 .
Tour Route Data Structure
[0170] The tour route can be as simple as a single path, which could also be termed a polyline. This is illustrated in FIG. 3 .
[0171] Where P 0 , P 1 and P 2 are the first three points along the path, where each point is defined by a longitude and latitude. The line segments are defined by a straight line between two adjacent points. The tour route, that is the nominal path a traveller would take consists of this path in the simple case.
[0172] To facilitate optional parts of a tour, a tour route can consist of multiple paths, whereby one path can join to one or more other paths, preferably in a directed manner, where a path represents an optional part of the tour.
[0173] In FIG. 4 , PO 1 through PO 12 are different path options. (For simplicity in the diagram, some of these path options are shown as a single line. Each, in fact, is a path, and therefore can consist of multiple line segments.)
[0174] In a preferred embodiment, paths are identified numerically, and a table structure lists the path connections. FIG. 5 shows the path connections for the tour route in FIG. 4 .
[0175] As mentioned above, each route point is defined by a longitude and latitude. In addition, each point also includes a nominal time. This time attribute specifies a nominal time (in seconds) at which a traveller could reach this point from the start of the path. This time parameter is used in calculating a nominal position within a music track when, for example, playing “return to tour” music.
[0176] Additionally, each route point preferably contains a width parameter defining the road width along the line segment to the next route point. This is used when determining whether or not particular coordinates are “on route” or “off route”.
Tour Point Types
[0177] A tour point is specified by a position along the tour route, and has associated with it the name of the audio file that should be played when the tour point is passed.
[0178] There are a number of different tour point types. These include:
Music Narration Navigation Stop
[0183] The system supports multiple audio channels, and particularly preferred embodiments support at least two audio channels—one for music, and the other for “talking”. “Talking” is defined as the audio associated with a tour point of type Narration, Navigation or Stop. Some preferred characteristics of the different tour point types are provided in the following table:
[0000]
Type
Description
Narration
Information that is either general in nature or of relevance
to the user's position.
Navigation
Directions about an impending turn. Navigation type tour
points have priority over narration and stop type tour
points.
As this provides important information, the system will
precede playing the specific audio with a particular audio
cue, for example, a chime that will grab the listener's
attention.
As mentioned, a navigation tour point has higher priority
over anything else playing on the talking channel at that
time. This means that if, for example, narration is playing
when a navigation tour point is encountered, the narration
is halted, and the navigation played.
After the navigation has completed playing, the narration
will recommence playing at the point it was interrupted.
With a short interval before playing the narration, and
appropriate fading down when it is being interrupted.
A short story of a few minutes, for example, could be
punctuated with some short navigation at appropriate
points.
Stop
A stop point is a tour point at an attraction of some sort.
Stop points preferably have the following:
A geographic region around the stop point that would
specify a stop zone region. This inhibits the system
from concluding that the user has travelled off tour,
when, for example, he or she is actually looking for
parking nearby.
Associated audio that would play when the user has
finished visiting the attraction. This audio could be
played on user demand by pressing a button on the
screen. This may also give the user directions on
how to get back onto the tour.
Music
The audio associated with this type of tour point is
music, and plays on the music channel. Music tour
points can also include features, such as:
A parameter that specifies if the music should keep
repeating along the tour route until the next music
tour point is encountered.
The ability to associate multiple audio files against
the tour point and have these files play in sequence.
[0184] The invention can play music and talking simultaneously, and this is described in detail below. Preferably, the audio of a single Narration, Navigation or Stop type tour point plays at any one time.
Tour Point Priority and Location Specificity
[0185] This component of the system is adapted to deal with the possibility that different users are likely to travel the route at different speeds. This means that if there are 2 narration type tour points near each other on the route, a traveller travelling at a faster speed will hear less silence after the first narration completes prior to the second narration starting.
[0186] Preferably, at maximum reasonable speed, the first audio does not run into the second. However, this may not be possible in all cases, and a number of features have been developed to assist the content developer in selecting priorities.
[0187] Each tour point has an associated priority and a location specificity parameter as follows:
Tour point priority. This is not a numeric priority scale, or a simple low-medium-high, but rather a Boolean setting of whether this tour point has a higher priority than the previous one. Location specificity setting
[0190] The location specificity setting indicates over what area of the route the tour point audio is valid. This is preferably one of the following:
[0000]
Type
Description
Location
The tour point audio must be played at the specified location,
Specific
or not at all.
Floating
The tour point audio is general in nature, its order in the
narrative is important, and is relevant regardless of the
specific location.
Nudge
The tour point audio is relevant to a particular area starting at
the location of the tour point, and finishing at a predetermined
location on the route specified by an “end nudge zone”
marker.
[0191] Depending on the location specificity setting and the tour point priority, when a tour point is encountered whilst a particular audio file is already playing on the same audio channel, the system can choose to do the following:
Stop what is currently playing on that channel, and play the new audio. Continue what is currently playing on that channel, and refrain from playing the new audio. Queue the new audio. When the currently playing audio completes, a decision will then be made about whether the queued audio will be played or not.
Tour Point Data Structure
[0195] A tour point data structure consists of information pertaining to a single tour point. This includes:
Position along the tour route. The Position data structure is defined below. Tour point type (music/narration/navigation/stop) Tour point priority (Boolean) Location specificity (specific/float/nudge) Nudge type tour points also indicate the furthest position along the route at which the tour point is still relevant Stop type tour points also include a stop zone region as well as a minimum stop time duration. The stop zone is a geographic region surrounding the tour point. This specifies a region whereby travel anywhere within this region will not be considered off tour. If the traveller stops for at least the stop point duration, within the stop zone, the system will flag that the traveller has stopped at the tour point. Maintain narration order flag (Boolean) A set of zero or more audio filenames, and for each a Tour Point Conditional Expression specifying the condition under which it should play.
Tour Point Conditional Expression
[0204] A tour point conditional expression consists of:
Expression type, which can be one of {always, inverse, conjunction, disjunction, named expression, has passed, has stopped, time dependent, date dependent, attraction dependent, speed dependent, acceleration dependent} An optional Parameter1 An optional Parameter2
[0208] The following describes the optional portions of the data structure depending on the Expression type.
[0000]
Expression type
Usage of optional parameters
Always
None
Inverse
Parameter1 - is a tour point conditional expression
Conjunction
Parameter1 - is a tour point conditional expression
Parameter2 - is a tour point conditional expression
Disjunction
Parameter1 - is a tour point conditional expression
Parameter2 - is a tour point conditional expression
Named
Parameter1 - name of an expression from the named
expression
expression list
Has passed
Parameter1 - name of a tour point
Has stopped
Parameter1 - name of a tour point
Time
Parameter1 - one of {Before, After}
dependent
Parameter2 - time of day
Date
Parameter1 - one of {Before, After, Equal}
dependent
Parameter2 - day of year
Attraction
Parameter1 - Attraction name
dependent
Parameter2 - one of {Opening, Closing}
Parameter3 - timeframe in minutes
Speed
Parameter1 - one of {Below, Above}
dependent
Parameter2 - speed (kilometres per hour)
Acceleration
Parameter1 - one of {Below, Above}
dependent
Parameter2 - acceleration (kilometres per
hour per second)
Parameter3 - time interval to earlier speed
reading (in seconds)
Named Expression
[0209] The purpose of named expressions is to allow for a complex expression to be defined once and used in multiple Tour Point Conditional Expressions.
[0210] The Tour Data Structure contains the Named Expression List. This consists of zero or more named expressions. Each named expression consists of:
A textual name An expression of type Tour Point Conditional Expression
Attraction Opening Entry
[0213] An Attraction Opening Entry defines the opening times of an attraction. It consists of the following elements:
Attraction Name One or more attraction opening slots of type Attraction Opening Slot Zero or more attraction opening exclusions lots of type Attraction Opening Slot. This defines any exclusions to the opening times specified by the attraction opening slots item.
Attraction Opening Slot
[0217] This defines a time of day and day of year, and consists of the following elements:
Start time—when the attraction is open End time—when the attraction closes Type—One of {Weekly, Monthly, Yearly} DaySet—a set of {Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday} MonthSpecificationType—one of {DayOfMonth, DayOfWeek} DayOfMonth—0 . . . 31 WeekOfMonthType—one of {First, Second, Third, Fourth, Last} MonthSet—a set of {January, February, March, April, May, June, July, August, September, October, November, December} YearSpecificationType—one of {DayOfMonth, DayOfYear}
[0227] The following describes the optional portions of the data structure depending on the Type element.
[0000]
Type
Usage of optional parameters
Weekly
DaySet - defines the set of days pertaining to this slot
Monthly
MonthSpecificationType - defines a subtype
If MonthSpecificationType is DayOfMonth:
DayOfMonth specifies the day of month
If MonthSpecificationType is DayOfWeek:
WeekOfMonthType specifies the week of month
DaySet - defines the set of days pertaining to this slot
Yearly
YearSpecificationType - defines a subtype
If YearSpecificationType is DayOfMonth:
DayOfMonth specifies the day of month
MonthSet specifies the month or months of the year
If YearSpecificationType is DayOfYear:
WeekOfMonthType specifies the week of month
DaySet - defines the set of days pertaining to this slot
MonthSet specifies the month or months of the year
Position
[0228] The Position data structure specifies a point on the tour route, not directly through the use of coordinates, but rather through reference to a line segment along the route.
[0229] It is specified by reference to the line segment, as well as a distance from the first point of the line segment. This is shown in FIG. 6 , whereby the tour point TP 1 is positioned along line segment LS 3 , at a distance of x metres from point P 2 .
[0230] This data structure is used to define the location of tour points along the route, as well as for other internal processing.
Tour Route Algorithms
[0231] The invention contains a number of algorithms for determining the current position along the route given current GPS coordinates. This algorithm is used each time the GPS receiver provides a location fix.
[0232] Given the current position along the route as well as the position along the route at the time of the last location fix, the system is able to determine what tour points, if any, have been passed. A determination that a tour point has been passed is used to trigger the audio associated with the tour point.
[0233] The algorithms also determine if the current location is too far away from the closest point on the route, in which case it deems that the traveller is off route. The algorithms and the manner in which the system applies them during a tour is discussed in more detail below.
Processes and System Routines
[0234] A. Process GPS
[0235] Each time GPS coordinates are available from the GPS receiver, the process illustrated in FIG. 8 is activated. This determines where on the tour route the current location represents, or if the coordinates represent a location that is off tour. Appropriate action is taken based on this result.
[0236] Step 301 calls the routine to determine the current “deemed position”. This could result in a determination that the coordinates are definitely on the route, with a route position defined by the closest line segment of the route, together with the distance along the line segment representing the point closest to the GPS coordinates.
[0237] The determination may be that the coordinates are too far away from the closest point on the route, in which case the deemed position is “unknown”. At the point where path options diverge, for example, near the intersection of PO 1 , PO 2 and PO 3 in FIG. 4 , a single determination cannot be made. Given the GPS signal accuracy, coordinates near this intersection could perhaps lie on either PO 2 or PO 3 . In such a case the deemed position is termed possible. This means that the coordinates do lie on the route, but a single definite position cannot be determined.
[0238] The deemed position will only be classified as “definite” if the position is forward along the route compared with the last determination. If the position is backward compared with the last determination, the distance between the current determination and the previous is calculated. If this distance is below a certain threshold, for example 30 m, the deemed position is classified as “minor reverse”. This allows for the traveller to perform a short reverse without the system indicating that the traveller is off route. This also allows for fluctuations in coordinates reported by the GPS receiver if the traveller is stationary to not cause an “off route” indication.
[0239] If the calculation between the current position on the route, and the previous one is such that it is greater than the threshold value for a minor reverse, the deemed position is classified as “unknown”, and the system gives an “off route” indication.
[0240] Different actions are required depending on the result of the deemed position determination. This is checked in step 302 .
[0241] Step 303 performs a check to guard against a particular scenario. The scenario can be illustrated with reference to FIG. 7 . Here, the intention is that the traveller will move along LS 1 , LS 2 , LS 3 and LS 4 in that sequence. However, if the traveller turns right from LS 1 into LS 4 , step 301 will still give a definite determination of the current coordinates when the traveller is on LS 4 . The desired result in this case is to consider that even though the traveller is on route, he is off the tour. This step performs a distance calculation along the length of the route between the last deemed position, and the current deemed position. If this distance is above a reasonable threshold, such as 80 m, this step concludes that the traveller has come off tour, and deems the current position as “unknown”.
[0242] Step 305 is reached if the traveller is on tour, and calls the Predictive Fading routine shown in FIG. 14 to fade down audio as necessary.
[0243] Step 306 considers the section of the route between the current deemed position and the deemed position from the previous GPS coordinates. For every tour point located within that interval, the Tour Point Passed routine is called (see below).
[0244] Step 307 checks to see if the current coordinates are within the stop zone of any of the tour's stop type tour points. If so, this step checks to see if the GPS coordinates indicate that the traveller has been stopped for at least the stop point's minimum stop duration. If this is the case, this tour point is added to the list of stop type tour points at which the traveller has stopped.
[0245] Step 308 checks to see if the traveller has just now returned to the tour. This is the case if the previous deemed position was unknown.
[0246] Step 309 starts playing music appropriate for this return to tour condition by calling the Start Return to Tour Music routine.
[0247] Step 310 gives a visual indication of the on tour condition.
[0248] Step 320 checks to see if the current coordinates are within the stop zone of any of the tour's stop type tour points. If so, this step checks to see if the GPS coordinates indicate that the traveller has been stopped for at least the stop point's minimum stop duration. If this is the case, this tour point is added to the list of stop type tour points at which the traveller has stopped. Step 321 checks to see if the current coordinates are within the stop zone of any of the tour's stop type tour points. If so, the traveller is considered to be “on tour” regardless of whether or not he is precisely on the tour's route.
[0249] A number of steps starting at step 322 are involved in detecting and processing the off tour condition. Step 322 checks to see if the current deemed position is classified as “unknown”. Step 323 checks to see if the previous deemed position was not unknown. If both these tests succeed, the system concludes that the traveller has come off tour. This is then processed in steps 324 and 325 .
[0250] Step 324 gives a visual indication of the off tour condition. Step 325 instructs the music audio processor to fade down any currently playing music, and then queues the playing of an off tour message to the talk audio processor.
[0251] B. Tour Point Passed Routine
[0252] This routine is called when a tour point has been passed, and is illustrated in FIG. 9 . At 601 it calls a routine to determine when the tour point's audio should be played (“Determine Play Time”). Based on the result at 602 , this routine branches to take the appropriate action:
1. Does not play any audio associated with the tour point 2. Initiates playing the tour point's associated audio. Special consideration is necessary for navigation type tour points, and this test is made at 603 .
Steps 604 , 605 and 606 are taken for narration and stop type tour points. Step 604 removes all tour points from the relevant (music/talking) tour point FIFO (“first in first out” queue) that are marked as being order specific. This is necessary as the tour points listed in that FIFO were passed prior to the tour point currently being processed and will potentially be played after this one completes. For tour points that are order specific, that later playing should not occur. Step 605 instructs the audio processor talking instance to terminate playing any currently playing audio. Step 606 calls the Initiate Audio routine to initiate playing of the appropriate audio file (see FIG. 13 ). A number of steps, starting at 610 are taken for navigation type tour points. Navigation type tour points will interrupt playing any currently playing audio, and this step determines if audio is currently playing on the talking channel. Step 611 instructs the audio processor talking instance to terminate playing the currently playing audio. Step 612 initiates the playing of a special audio file for the “navigation chime” sound on the talking audio process. This then calls the Initiate Audio routine to queue the playing of the appropriate audio file specified by the tour point with the navigation direction. The resulting sound is the navigation chime immediately followed by the navigation direction. This navigation audio is interrupting the currently playing narration audio. Step 613 cues a brief period of silence followed by the remaining portion of audio that was interrupted at step 611 .
[0263] Step 614 is executed if there is no audio currently playing on the audio processor talking instance. It initiates the playing of a special audio file for the “navigation chime” sound on the talk audio processor. This then calls the Initiate Audio routine to queue the playing of the appropriate audio file specified by the tour point with the navigation direction. The resulting sound is the navigation chime immediately followed by the navigation direction.
3. Step 620 is the first in a number of steps taken if the tour point should not be played immediately, and should be considered for possible later playing.
This step checks to see if the talking tour point FIFO is full, i.e. it already has a number of tour points already in queue equal to the FIFO's maximum capacity. Step 621 is called if the FIFO is already full, and removes the last tour point from it. This action is taken because the Determine Play Time routine (see below) has already determined that the current tour point has higher priority than the last tour point in the FIFO. Step 622 queues the tour point to the talking tour point FIFO, for possible later playing. Being in this queue does not guarantee that this tour point's audio will later be played, however it will be considered for playing when previous audio has completed playing.
[0268] C. Determine Play Time Routine
[0269] This routine determines when the audio for a specified tour point should be played, and is illustrated in FIG. 10 .
[0270] The main factors involved in making this determination are:
1. If audio is currently playing on the appropriate channel, and if so is it navigation type audio (which has an implicit high priority) 2. The tour point's location specificity 3. The tour point's priority
[0274] Step 701 checks to see whether or not the conditions of play for any of the audio files associated with the tour point are satisfied. If none of the possibly multiple audio files associated with the tour point have satisfied conditions, the tour point is essentially ignored, and the routine's result is “Don't Play”.
[0275] Step 702 determines which is the relevant audio processor instance for this tour point. For music type tour points, the music audio processor instance is relevant. For narration, navigation and stop type tour points, the talk audio processor instance is relevant.
[0276] If no audio is currently playing on the relevant audio processor, then the current tour point's audio can immediately play. This is checked in step 703 .
[0277] Navigation type tour points implicitly have higher priority than any audio currently playing. This is checked in step 704 .
[0278] The next step in determining the play time depends on whether or not the tour point is classified as being location specific. This is checked in step 705 .
[0279] Steps 706 and possibly 707 execute if the current tour point is location specific. Location specific tour points must either play immediately as they are passed, or not played at all.
[0280] As navigation has higher priority than other tour point types, whether or not the currently playing audio is for navigation is examined at step 706 . If navigation is currently playing, then the current tour point has lower priority and the routine's result is “Don't Play”.
[0281] Step 707 is reached if both the current tour point and the currently playing audio is for narration. The current tour point's audio will be played if the tour point is specified as being “higher priority”. Otherwise, its audio will not be played.
[0282] Step 708 is reached if audio is currently playing in the current tour point is not location specific, that is it has either a location specificity of float, or of nudge. The test at step 708 determines if the appropriate tour point FIFO is already full. If the FIFO has capacity to queue an additional tour point, then this routine's result is “Queue”.
[0283] Otherwise, step 709 determines if the current tour point has higher priority than the last tour point in the FIFO. A higher priority tour point will be queued, whilst a tour point that is not specified as being higher priority will not be queued or played.
[0284] D. Music Stopped Routine
[0285] This routine is called by the music audio processor when a music file completes playing. This is illustrated in FIG. 11 . This routine's job is to initiate playing audio of the next tour point in the music tour point FIFO. This is only done if the current position along the route is within that specified by the tour point's location specificity.
[0286] Step 801 first checks to see if the music tour point FIFO is empty. If the FIFO is empty, this routine has no further work to perform.
[0287] Step 802 removes the oldest tour point from the FIFO, making it available for further examination in later steps of this routine.
[0288] Only tour points with location specificity of either float or nudge will have been queued onto this FIFO in the first place. Step 803 examines the tour point's location specificity to see which it is.
[0289] Step 804 is reached if the tour point has a location specificity of nudge. Tour points with this location specificity have an associated predetermined endpoint specified. This endpoint defines the furthest position along the tour route at which point the tour point's audio is allowed to start playing. This step compares the current deemed position along the route with this endpoint. If the current deemed position is passed the endpoint, the tour point's audio is not played.
[0290] Step 805 is reached when the previous tests have shown that the tour point's audio should be played. This calls Initiate Audio to initiate playing of the audio associated with the tour point.
[0291] E. Talking Stopped Routine
[0292] This routine is called when talking completes playing, and is illustrated in FIG. 12 . Its job is to:
1. Initiate playing audio of the next tour point in the talking tour point FIFO. Again, this is only done if the current position along the route is within that specified by the tour point's location specificity. 2. Now that talking has stopped, initiate fade up of the music if appropriate.
[0295] Step 901 first checks to see if the talking tour point FIFO is empty. If the FIFO is empty, there is no further talking to play.
[0296] If there is no further talking to play, the music may need to be faded up. Step 902 first checks to see if music is currently playing. If not, this routine ends.
[0297] In step 903 the routine tests to see if the system predicts passing another talk type tour point imminently. This prediction is made within the Predictive Fading routine of FIG. 14 , and stored in a module variable that is accessed here. If the system predicts that it is about to pass another talk type tour point, there is no point fading up the music and then immediately fading it back down again.
[0298] In step 904 the routine instructs the music audio processor to fade up that channel over a period such as 3 seconds.
[0299] Step 905 removes the oldest tour point from the FIFO, making it available for further examination in later steps of this routine.
[0300] Only tour points with location specificity of either float or nudge will have been queued onto this FIFO in the first place. Step 906 examines the tour point's location specificity to see which it is.
[0301] Step 907 is reached if the tour point has a location specificity of nudge. As explained above, tour points with this location specificity have an associated predetermined endpoint specified. This endpoint defines the furthest position along the tour route at which point the tour point's is allowed to start playing. This step compares the current deemed position along the route with this endpoint. If the current deemed position is passed the endpoint, the tour point's audio is not played.
[0302] Step 908 is reached when the previous tests have shown that the tour point's audio should be played. This calls Initiate Audio to initiate playing of the audio associated with the tour point.
[0303] F. Initiate Audio Routine
[0304] This routine is called to initiate playing the audio associated with a specific tour point. It is illustrated in FIG. 13 .
[0305] Different actions need to be taken depending on whether the specified tour point is of type music or of type talking. This is checked in step 1001 .
[0306] Step 1002 is the first in a sequence of steps handling a talk type tour point. Audio of a talk type tour point preferably plays at a nominated volume referred to as the talking volume level.
[0307] When talk is playing, it is intended that the music plays at a soft level. Typically prior to nearing the talk type tour point a prediction of this will be made, and an appropriate fade down of the music initiated. However, an accurate prediction cannot always be made, for example due to an accelerating vehicle. Step 1003 examines the music audio processor to determine whether or not the previously initiated fade down of music has completed.
[0308] If the fade down of music has not completed, step 1004 instructs the music audio processor to hasten the fade operation, so that there will be minimal overlap of high volume music whilst talking commences.
[0309] Steps 1005 and 1006 determine what volume level at which the music should play. If talking is currently playing, or if the system has predicted that talking is expected to shortly commence, the volume level is set to soft level referred to as the faded music volume level 1007 . This prediction is made by the Predictive Fading routine in FIG. 14 .
[0310] Otherwise, there is no talking currently playing and the system has not predicted passing a talk type tour point, so the music can play at a louder level referred to as the normal music volume level 1008 .
[0311] Each tour point can have associated with it multiple audio files to play when the tour point is passed. Associated with each audio file, is an expression which must evaluate to true for the associated audio file to be played. If multiple expressions hold true, then the first expression that evaluates to be true takes precedence, and its associated audio files selected 1009 . This is where Fine-Grained Narration Personalisation may be utilised (see below). This step calls the Conditional Expression Evaluation routine for each expression associated with the tour point.
[0312] Step 1010 determines which is the relevant audio processor instance for this tour point. For music type tour points, the music audio processor instance is relevant. For narration, navigation and stop type tour points, the talk audio processor instance is relevant.
[0313] Step 1011 instructs the relevant audio processor to commence playing the audio file determined in step 1009 at the volume level determined.
[0314] Step 1012 adds this tour point to the list of tour points that have been passed on the tour. This is part of the “tour state” maintained by the system.
[0315] In traditional audiovisual media people are accustomed to having background music whilst talking or other action takes the forefront. The music or score serves to create an emotional bed for the visuals, often the viewer is not even conscious of its existence. In these media, mixing of music, dialogue, narration and any other sound is the job of the editor.
[0316] The subtle fading between music and talking is absolutely critical to create a seamless media experience.
[0317] In a basic GPS narration system, premixing of music and talking cannot be done. Talking, consisting of narration and navigation style messages, may last a few seconds or a few tens of seconds for example, and commences playing at particular points along the route.
[0318] A music track can go on for many minutes, during which time multiple pieces of talk could start and stop. Whilst talking is playing, music is played at a soft volume, and whilst talking has stopped, music is played at a louder volume.
[0319] So that the transition between the soft playing of music and the loud playing of music sounds smooth, the music volume is faded between soft and loud over a period of a few seconds.
[0320] This is the “dynamic” component of music mixing, and has already been discussed in some detail above. The “predictive” component refers to when the music starts to fade. As mentioned, whilst talk is playing, the music is playing at a soft volume. When the talk completes, the music starts to fade up as soon as this occurs, and completes after a constant period of time, for example, over 3 seconds.
[0321] Knowing when to start fading down music is more complicated. The ideal is that the fade down occurs over a specific time period (again, for example, 3 seconds), timed such that it completes just as the talking commences.
[0322] This requires being able to predict when the traveller is 3 seconds from a particular point on the route. This is done by:
Determining the current speed from the GPS receiver Determining the current position on the route Determining the distance to the next tour point on the route
[0326] Once it has been calculated that the traveller is 3 seconds from the next tour point, the music begins to fade. The present algorithm initiates a fade regardless of any subsequent change in speed of the traveller.
[0327] If the traveller decelerates, then the music will complete fading down to the soft volume prior to the talk playing. Audibly this sounds reasonable.
[0328] If the traveller accelerates, then the music will still be quite loud as the talk starts playing. As the traveller passes the tour point and the talk starts playing, a fast “fade down” occurs (for example over 0.7 seconds). This ensures that there is a minimum of time whilst the talking commences that the music is still louder than desired.
[0329] G. Predictive Fading Routine
[0330] This routine is called whenever a location fix is supplied by the GPS receiver, and the Process GPS routine has determined the corresponding position on the route. This routine's job is to predict where the traveller will be along the route after x seconds.
[0331] It then determines if any tour points lie along the stretch of the tour route to that position, and if so, determines what fading should occur. This is illustrated in FIG. 14 .
[0332] Step 1101 compares the deemed position determined by the Process GPS routine in FIG. 8 from the current GPS coordinates, with the deemed position calculated from the previous GPS coordinates. A comparison of these deemed positions reveals if the traveller is moving forward along the route or not.
[0333] Step 1102 calculates the current speed, using speed=(distance/time). Where the distance is the total distance travelled as derived from the last n GPS readings, and time is the time interval from the first and the last of these n readings. n is chosen such that the time interval is no greater than a certain threshold, such as 2 seconds.
[0334] Step 1103 calculates the prediction distance, i.e. the distance that is expected to be covered at the current calculated speed over the prediction time, which can be 3 seconds, for example. This is calculated by distance=speed*time.
[0335] Step 1104 takes the current deemed position and follows the route for the distance calculated in the previous step. This results in a predicted position, defined by a particular line segment within the route data structure, and the distance along that line segment.
[0336] Step 1105 is the commencement of a loop that considers the interval starting from the prediction position calculated in the last call to this routine, and the current prediction position.
[0337] Step 1106 searches the list of tour points of the tour, and finds the first playable tour point within the route interval from step 1105 . Playable is defined as having at least one condition of play for any of the audio files associated with the tour point being satisfied.
[0338] The fading actions that occur are different depending on the tour point type which the system predicts it will pass, and the tour point type is checked in step 1107 .
[0339] Step 1108 is the first in a series of steps for talk type tour points. This checks to see if talking is already playing on the talk audio processor.
[0340] By step 1109 the system has determined that there is no talk currently playing. The system checks with the music audio processor to see if music is currently playing.
[0341] At step 1110 the system has determined that music is currently not playing, so there is no music to fade down. In this case the system remembers in a module variable that it has predicted passing a talk type tour point. This is used in the Initiate Audio routine, allowing it to correctly determine what volume level to start playing any music.
[0342] Step 1111 instructs the music audio processor to fade down the music over an appropriate interval, such as 3 seconds. The music is faded from the current volume level, down to the faded music volume level.
[0343] At step 1112 , the system predicts that the traveller is soon to pass a talk type tour point and that talk is currently playing. The next course of action depends on whether the predicted tour point is location specific and higher priority than the current one. If so, the predicted tour point must be played immediately when it is passed and the current one terminated. To provide a smooth effect, step 1113 instructs the talk audio processor to fade down the current talk from its current volume level down to zero, and then to stop playing that file.
[0344] Step 1120 is the first in a series of steps involving music type tour points. This checks to see if music is already playing on the music audio processor.
[0345] At step 1121 , the system predicts that the traveller is soon to pass a music type tour point and that music is currently playing. The next course of action depends on whether the predicted tour point is location specific and higher priority than the current one. If so, the predicted tour point must be played immediately when it is passed and the current one terminated. To provide a smooth effect, step 1122 instructs the music audio processor to fade down the current music from its current volume level down to zero, and then to stop playing that file.
[0346] Step 1130 searches forward along the tour route starting at the position of the current tour point, towards the end of the interval considered in step 1105 . If another tour point is found, it is processed in a similar way from step 1107 .
[0347] Any period where talking is playing and music is louder than desired does not necessarily sound good to the user. Accordingly, it is preferable that:
Between the time the music fade commences and the tour point is physically reached, the traveller's speed is continuously analysed. If the traveller is accelerating, the speed at which the fade down occurs is accelerated. This will not guarantee that the fade will complete by the time the tour point is reached and the talking begin to play, but should minimise this interval. Playing the talking is delayed until the fade completes. It is preferable for audio to be played as closely as possible to the intended position along the route. GPS receivers are accurate to approximately 15 m, so in general additional delays are not desirable.
[0350] Some preferred embodiments of the invention also include a number of additional features.
H. Conditional Expression Evaluation
[0351] The background to this is the concept of Fine-Grained Narration Personalisation, which can personalise and contextualise the audio information, to provide a natural, narrative effect to the user.
[0352] Preferably, the narration is recorded using various real characters including someone having the role of “tour guide”. A number of concepts described here ensures that tourists will not feel that their computer-based tour guide is a recording that simply announces at specific locations.
[0353] In general terms, the narration is personalised based on the tour state at the time of the narration. A human tour guide would tailor the commentary in such a way, and Fine-Grained Narration Personalisation seeks to provide similar such tailoring. The tour state may depend, for example, on whether or not part of the tour was taken. Previous narration may have guided a tourist to a particular tour point that is expected by the content developer to be of interest. However, whether or not a tourist actually went passed a tour point will be an individual matter, and as such is part of the tour state.
[0354] The Tour State data structure consists of items relating to the current tour state. This is held in non-volatile storage so that it will still be available should the system be restarted.
[0355] The tour state includes a list of tour points that have been passed. This list is emptied when the tour is started, and is updated by the Initiate Audio routine.
[0356] The tour state also has a list of stop type tour points at which the invention deems the traveller to have stopped at. This is updated by the Process GPS routine.
[0357] Narration can be tailored based on the Tour State data. For example, if the tourist had passed a previous tour point, the narration could be “The mediaeval steeples of the approaching church are very different to those of the Gothic church we saw earlier today”. If the tourist had not passed the previous tour point, the narration could be different, for example “you will notice the mediaeval steeples of the approaching church. Shame you missed the Gothic church earlier today—there is such a contrast!”
[0358] There are multiple advantages for narration tailoring. Firstly, tailoring provides the possibility of richer content. In an informational sense, being able to refer back to previous experiences allows the narration to compare points of interest. Interesting facets can therefore be highlighted in a way not possible if narration about a point of interest must be stand-alone only. Tailoring also creates a subtle feeling of a personal tour for the tourist and of interactivity. The narration is therefore not simply about the point of interest, but is subtly about the tourist as well.
[0359] There are many conditions on which narration tailoring can occur. Some of these have been touched on above and those and others include:
Passed Tour Point Condition. This condition is true if the tourist had actually passed a specific tour point, and is illustrated in the above example. Stop Point Dependent Conditions. A Stop Point is a tour point where the content developer expects that the tourist will spend some time to experience. This condition is different to the “Passed Tour Point” condition described above. For this to be true, it does not only require that the tourist passed a particular tour point, but also that he remained there for a certain minimum duration. Time Dependent Conditions. For example, if a tour point is passed around dusk, the following narration would be appropriate “At this time of day, we really need to drive carefully . . . the kangaroos love crossing this stretch of road”. Or if travelling earlier on “At dusk this stretch of road is amazing . . . the kangaroos really love crossing here” Date Dependent Conditions. Narration can be similarly tailored based on date ranges. This could be useful for example in describing features differently depending on season in which the tour is taken. Attraction Opening Times Dependent Conditions. The tour scheduler described later, contains information regarding facility opening times. An “attraction” in this context could be a shop, museum, market or a local event for example. Conditions based on attraction opening times could be date and/or time relative. Narration tailoring would permit “the markets are open today, so if local jams, preserves and remedies take your fancy pull up just ahead”, or “this quiet stretch of road turns into a bustling market every Sunday complete with . . .”. The use of Attraction Opening Times as a condition requires a detailed database of attraction opening times. Each attraction is identified by name, and includes a list of opening times. The opening times can be specified differently based on day of week or day of month, and can include exception cases as well. Preferably, the tour data structure does not include this information directly, but rather includes the filename of the file that possesses this information. Speed/Acceleration Dependent Conditions. An enhanced sense of personalisation can be achieved by occasional narration perhaps referring to traffic jams, or going over the speed limit. Tour Scheduler Dependent Conditions. The tour scheduler contains information regarding future tour activities. Tourists may or may not have used the scheduler, and so specific tour activities may be unscheduled, scheduled to occur or scheduled not to occur. Conditions based on activity schedule can allow for narration such as “I know you haven't decided yet about going to see the blowhole later on today, but if you want to get an idea of where the locals go to on a sunny afternoon, that is your best bet”. Or, “if you like the view from up here, you are in for a real treat when we get to Cathedral Mountain later on”. Tour Scheduler preferably adapts the itinerary dynamically. For example, based on having a full day of touring scheduled and wanting to have the tour completed by a reasonable time. It is also based on such things as lunch requirements or opening times of attractions. For example, if a traveller is running late, there is no point sending him/her on a 20 kilometre drive to an attraction if it would be closed by the time the traveller reaches there. The system makes reasonable recommendations to the traveller so that they know what is happening, and can make an informed decision.
Expressions
[0371] An expression is built on top of one or more of the conditions defined above, and can be thought of as complex conditions. For example, an expression can be:
A Boolean condition The logical inverse of Expression1 The logical conjunction of Expression1 with Expression2 The logical disjunction of Expression1 with Expression2 A named expression
Named Expressions
[0377] Some expressions may need to be used in a number of places. Named expressions are defined in as part of the Tour Data Structure, and can be used multiple times for Fine-Grained Narration Personalisation.
[0378] One or more of the conditions and/or expressions can be used in varying embodiments of the invention.
Flow Chart Description
[0379] This routine is called to evaluate a Tour Point Conditional Expression, and is used to determine which if any audio file should be played when a tour point is passed for instance. It is illustrated in FIG. 15 . Note that some elements of this routine are not shown in the figure, and are only described textually below,
[0380] A Tour Point Conditional Expression has a type element which is evaluated by steps 1201 , 1202 , 1203 , 1204 , 1220 , 1221 , 1222 and 1223 to determine how the expression element will be evaluated.
[0381] If the expression type is Always, then 1210 is processed, and the routine returns true.
[0382] If the expression type is Inverse, then 1211 calls this routine recursively to evaluate Parameter 1 as the expression, and 1214 inverses this result.
[0383] If the expression type is Conjunction, then 1212 calls this routine recursively to evaluate Parameter1 and Parameter2 as expressions, and 1215 calculates the conjunction of these results.
[0384] If the expression type is Disjunction, then 1213 calls this routine recursively to evaluate Parameter1 and Parameter2 as expressions, and 1216 calculates the disjunction of these results.
[0385] If the expression type is Has Passed, then 1230 looks up the tour point has passed list, and returns true if the tour point named by Parameter1 is on the list.
[0386] If the expression type is Has Stopped, then 1231 looks up the tour point has stopped list, and returns true if the tour point named by Parameter1 is on the list.
[0387] If the expression type is Time Dependent, then 1232 checks Parameter1. If Parameter1 is Before, and if the current time of day is before the time specified by Parameter2, this routine returns true. If Parameter1 is After, and if the current time of day is after the time specified by Parameter2, this routine returns true.
[0388] If the expression type is Date Dependent, then 1233 checks Parameter1. If Parameter1 is Before, and if the current date is before the date specified by Parameter2, this routine returns true. If Parameter1 is Equal, and if the current date is equal to the date specified by Parameter2, this routine returns true. If Parameter1 is After, and if the current date is after the date specified by Parameter2, this routine returns true. In performing these date comparisons, only the day and month components of the date are considered, and the year is ignored.
[0389] If the expression type is Attraction Dependent, then 1234 accesses the Attraction Opening Database for the Attraction Opening Entry specified by Parameter1. If there is no such attraction in the database, then this routine returns false if Parameter2 is Opening, and true if Parameter3 is Closing. If there is the named attraction in the database, then this routine evaluates all associated Attraction Opening Slots and exclusion slots against the current time and date and the timeframe specified by Parameter3.
[0390] If the expression type is Speed Dependent, then the instantaneous speed is determined by calculating the distance and time between the last 2 GPS readings. This routine returns true if the speed is greater than Parameter2 and Parameter1 is Above, or the speed is less than Parameter2 and Parameter1 is Below.
[0391] If the expression type is Acceleration Dependent, then the current speed is determined by calculating the distance and time between the last 2 GPS readings. The previous speed is determined by calculating the distance and time between the 2 consecutive GPS readings that were taken closest to n seconds previously, where n is equal to Parameter3. The acceleration is calculated using the current speed, the previous speed and the time interval between those readings. This routine returns true if the acceleration is greater than Parameter2 and Parameter1 is Above, or the acceleration is less than Parameter2 and Parameter1 is Below.
I. Determine Deemed Position
[0392] This routine is used to determine the current “deemed position”. This could result in a determination that the coordinates are definitely on the route at an identifiable single position, definitely off the route, or on the route at an unidentifiable position. This is illustrated in FIG. 19 .
[0393] The processing of this routine depends on the last determined deemed position state, and this is tested in steps 1601 and 1602 . On system initialisation the deemed position state would be set to “unknown”.
[0394] If the last determined deemed position state is “unknown”, then 1610 calls the routine to determine the Initial Positions List. The reference position, i.e. the current GPS coordinates, may be too far away from the route to be considered “on route”, in which case the Initial Positions List will be empty. This is checked in step 1611 .
[0395] If there is 1 or more Positions in the Initial Positions List, the deemed position state is changed to DirectionScanning so that future GPS coordinates will be suitably processed. This is done in 1612 .
[0396] Step 1604 is processed if this routine is called when the deemed position state is DirectionScanning and calls the Find IPL Forward Moving Positions routine. Step 1605 checks to see whether or not the current coordinates were considered forward moving along the route relative to the Initial Positions List. Step 1606 calls the routine to select one of the positions from the Forward Moving Positions List as the deemed position, and step 1607 changes the deemed position state to Definite.
[0397] The multistage process of determining the Initial Positions List, the subsequent determination of the Forward Moving Positions list and the selection of one of these positions as the deemed position leads to multipass support, whereby the tour route can double back on itself in certain parts over the same geography, and the invention will correctly work out where on the route are the current coordinates, given where the tour has previously been.
[0398] Step 1603 is performed when the last deemed position state is either “definite”, “minor reverse” or “possible”. Its job is to determine the current deemed position along the route, as well as the deemed position state.
[0399] The determination may be that the coordinates are too far away from the closest point on the route, in which case the deemed position is “unknown”. At the point where path options diverge, for example, near the intersection of PO 1 , PO 2 and PO 3 in FIG. 4 , a single determination cannot be made. Given the GPS signal accuracy, coordinates near this intersection could perhaps lie on either PO 2 or PO 3 . In such a case the deemed position is termed possible. This means that the coordinates do lie on the route, but a single definite position cannot be determined.
[0400] The deemed position will only be classified as “definite” if the position is forward along the route compared with the last determination. If the position is backward compared with the last determination, the distance between the current determination and the previous is calculated. If this distance is below a certain threshold, for example 30 m, the deemed position is classified as “minor reverse”. This allows for the traveller to perform a short reverse without the system indicating that the traveller is off route. This also allows for fluctuations in coordinates reported by the GPS receiver if the traveller is stationary to not cause an “off route” indication.
[0401] If the calculation between the current position on the route, and the previous one is such that it is greater than the threshold value for a minor reverse, the deemed position is classified as “unknown”, and the system gives an “off route” indication.
J. Determine Initial Positions List
[0402] The routine illustrated by flowchart shown in FIG. 16 , is used as part of the process to determine where on the route is the reference point, the reference point being the current GPS coordinates. The output of this routine is the Initial Positions List, which is a list of zero or more positions on the route that are sufficiently close to the reference point. This routine operates by looping through all paths in the route. Step 1301 initialises the loop to start from the first path. It also clears the initial positions list.
[0403] Step 1302 is the start of the loop for each path. There is a sub loop commencing at step 1303 that operates on every point in the path. 1302 initialises the loop to start at the first point.
[0404] 1303 obtains the coordinates for the current point in the loop as well as the next point.
[0405] 1304 calculates the distance between the reference point and the line segment defined by these two points.
[0406] 1305 determines whether or not this distance is close enough to the route so that it can be classified as being on the route. In one embodiment, the maximum permitted distance is 35 m. In another embodiment, the maximum permitted distance would be a function of the path width.
[0407] Step 1306 is the start of a few steps that are executed if the reference point is classified as being on route. 1306 calculates the position along the line segment that is closest to the reference point.
[0408] Step 1307 is used to ensure that only significantly distinct positions are added to the initial positions list at 1308 . It does this by looping through all positions already in the initial positions list, and calculating the distance between Pos and each position. If the distance any existing position is greater than a certain threshold, preferably 100 m, the position is considered distinct and added to the list at 1308 .
[0409] Steps 1309 and 1310 continues the loop that iterates through all points on the current path.
[0410] Steps 1311 and 1312 continues the loop that iterates through all paths on the route.
K. Find IPL Forward Moving Positions
[0411] The routine illustrated by flowchart shown in FIG. 17 , is used as part of the process to determine where on the route is the reference point, the reference point being the current GPS coordinates. The output of this routine is the Forward Moving Positions List, which is a list of zero or more positions on the route that are sufficiently close to the reference point.
[0412] The maximum number of positions that will be output onto this list will be equal to the number of positions in the Initial Positions List when this routine is called.
[0413] This routine operates by looping through each position in the Initial Positions List, and step 1401 initialises IpIIndex to start from the first entry in the list.
[0414] Step 1402 , 1403 and 1404 setup variables used in later processing.
[0415] Step 1406 determines whether or not reference point is close enough to the current line segment such that it can be considered on route.
[0416] Step 1408 calculates the distance along the route as described, and does this by looping through the points between IpIPos and Point 1 , adding in the distance calculated in step 1407 .
[0417] Step 1409 determines whether or not this distance reaches the threshold such that we can now consider the reference position to have moved sufficiently forward of the associated position in the Initial Positions List.
[0418] Step 1410 adds the position to the Forward Moving Positions list.
[0419] Steps 1412 and 1413 complete the loop that attempts to find a forward moving position for.
[0420] Steps 1411 and 1414 completes the loop to process all positions from the Initial Positions List.
I. Select Initial Deemed Position
[0421] The routine illustrated by flowchart shown in FIG. 18 , is used to select which of the possibly multiple positions within the Forward Moving Positions list should be selected as the Initial Deemed Position.
[0422] This routine operates as two loops, the outer loop processing each position within the Forward Moving Positions list. The inner loop is used to determine whether or not the position has been passed whilst previously on the tour.
J. Start Return to Tour Music
[0423] This routine is called when a traveller's position becomes definite, and is used to start playing appropriate music. This is shown in FIG. 20 .
[0424] Step 1701 determines the list of music tour points located before the reference position, and has an audio length such that at the nominal travel times included in the Tour Route Data Structure, the audio would complete playing prior to the reference position.
[0425] Step 1702 checks to see if there is at least one tour point that matches this criteria. If there are none, no music is started.
[0426] Step 1703 one of the possibly multiple tour points in the music intersection list. Preferably, this selection will be based on the tour point closest to the reference point.
[0427] 1704 calculates the time that it would take under nominal travel times included in the Tour Route Data Structure, between the tour point position and the reference position.
[0428] Step 1705 instructs the music audio processor to start playing the tour point's audio starting at the time calculated in the previous step. This step also instructs the music audio processor to fade the music up.
Travel Navigation Software Integration
[0429] In one embodiment of this invention, there is limited user interface, primarily to cater for tour selection. In another embodiment, the system of this invention is integrated with commercially available travel navigation software. In this case, the user interface is a combination of the elements described in this specification, together with the user interface provided by the travel navigation software. This would include a map of the area together with the current traveller's location and direction highlighted.
[0430] In one anticipated use of the system, the traveller would stay on the pre-defined tour route for certain periods of time, whilst being guided and entertained by the invention.
[0431] However, there will be times when the traveller wants to explore something by himself and leave the tour route. On many of these occasions the user will require guidance to the desired destination, which is not on the tour route.
[0432] For such circumstances, in some embodiments this invention integrates commercially available travel navigation software to provide guidance to the traveller when not on the pre-defined tour route. This is of use in several scenarios including:
1. When the user is on tour or off tour and wants to travel to a particular off tour destination 2. When the user is off tour and wants to return to the tour
[0435] Although the traveller is free to select and activate the Travel Navigation Software at any point in time from the invention's user interface, the system automatically does this when it detects that the traveller has come off route.
[0436] When the traveller wants to return to tour, a certain selection is made from the user interface. This includes the following options:
1. Return to where the tour was last left 2. Go to the closest point on the tour from the current location 3. Go to a specific point on the tour. The traveller is presented with a list of significant points on the tour, from which a selection can be made.
[0440] Once the selection has been made, the Travel Navigation Software is instigated to give directions to the traveller. Once it has been determined that the traveller is on the tour route, the Travel Navigation Software is disengaged. At this point return-to-tour music recommences (if appropriate) and the standard in-tour operation of the invention continues.
[0441] As previously touched on, music recommencement occurs by performing various calculations when the system determines that the traveller has returned to the tour. This involves determining what is the nearest music type tour point prior to the return-to-tour position.
[0442] Based on the nominal speeds associated with the tour route, the system calculates the nominal position (timewise) within the music track. It then commences playing the music from this nominal position. The music is played or mixed with talk depending on the presence of a talk type tour point at the position where the traveller returns to tour.
[0443] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.
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A system and method for delivering contextually enhanced location based media for tour guidance. Tours are constructed upon a directional tour route, the route potentially comprising optional parts. Media is associated with tour points and is delivered based on position and order along the directional tour route. Tour points also have characteristics and priorities which also affect determination of media delivery. The system can also make use of non-spatial contextually relevant data such as tour history, temporal factors and velocity in determining media selection. The system can dynamically mix multiple channels of triggered media in real time, and can adjust properties of the playing media in response to predicted movements along the route.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] The present application claims priority to Korean patent application number 10-2009-0018451, filed on Mar. 4, 2009, which is incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a highly integrated semiconductor device, more particularly, to a fuse within a highly integrated semiconductor device that is capable of determining whether to transfer an electronic signal or connect two different terminals.
[0003] A fuse is generally used in many electrical and electronic devices. In a normal condition, the fuse allows current to flow in the circuit. However, when the fuse is cut in the overcurrent condition, the fuse permanently makes whole or partial of the circuit shut off. Unlike a is switch, the fuse cannot be used for temporarily turning on or off current flow in a circuit.
[0004] A semiconductor device is made to perform a specific operation by a fabrication process including injecting an impure material and depositing conductive and nonconductive materials onto a predetermined area of a wafer mounted in a chamber. One example of the semiconductor device is a semiconductor memory device. The semiconductor memory device includes plural components or elements such as a transistor, a capacitor, a resistor, a fuse, and etc. Herein, the capacitor is mainly used for temporarily storing data, and the fuse is used in a redundancy circuit or a power supply circuit of the semiconductor memory.
[0005] The redundancy circuit using the fuse for permanently storing address of a defective cell (or unit cell) replaces the defective unit cell with a spare cell in order to prevent the semiconductor memory device having a minor defect from being treated as a defective product, thereby increasing the yield. Recently, a memory chip density of the semiconductor memory device increases. When few unit cells in the semiconductor memory device are defective, destroying the semiconductor memory device including few defective cells can be ineffective and result in a reduced yield because a ratio of normal cells to defective cells in the semiconductor memory device is likely to be very low. Thus, when detecting any defective unit cell during manufacturing and testing process of the semiconductor memory device, the redundancy circuit replaces the defective unit cell with a redundant memory cell in a repair process in order to secure a higher yield for semiconductor devices having a plurality of unit cells.
[0006] When a particular unit cell of the semiconductor memory device is defective, a repair process for substituting the defective unit cell with a spare cell is performed. Namely, an address for accessing the defective unit cell is inputted externally. The repair process is performed in which the address of the defective unit cell is stored to prevent the defective cell from being accessed, and allow another cell to be accessed in place of the defective cell. The fuse is the most commonly used device among those that are used to store the address of the defective unit cell during the repair process. An electronic connection is permanently disabled by applying a laser beam to a target fuse in the semiconductor device, and the address of the defective unit cell can be permanently stored (or programmed) by such a fuse blowing operation.
[0007] During a fabricating process of the semiconductor memory device including a plurality of unit cells before the fabrication process of the semiconductor memory device is completed, it is difficult to know which cells among the plurality of unit cells would become defective, i.e., the location or address of a defective cell. Accordingly, a fuse box having a plurality of fuses can be additionally implemented in the semiconductor memory device in order to substitute a normal spare cell for the defective unit cell located in any area of the memory chip.
[0008] As the data storage capacity of a semiconductor memory device is increased, the semiconductor memory device is provided with an is increased number of unit cells as well as an increased number of fuses for substituting the defective unit cell with an extra unit cell. However, as the semiconductor memory device is required to have a decreased chip size, the semiconductor memory device needs to have a high integration density. As described above, laser is selectively applied to physically blow a portion of the fuses and therefore. In order not to affect fuses adjacent to the targeted fuse, a sufficient spacing between adjacent fuses should be provided. However, this hinders the obtaining of a high integration density of the semiconductor memory device.
[0009] FIGS. 1 a and 1 b are respectively a circuit diagram and a plan view illustrating a fuse arrangement (or fuse block) in a semiconductor device according to the related art.
[0010] Referring to FIG. 1 a , a first fuse block 100 and a second fuse block 150 respectively include a plurality of fuses F 1 through F 4 coupled between a power supply voltage VDD and a ground voltage VSS, switching elements PT and NT for controlling a coupling between the power supply voltage VDD and the ground voltage VSS, and control units N 1 through N 4 that are controlled by fuse control signals, <B>, <C>, <D>, <E> for the first fuse block 100 and < 2 >, < 3 >, < 4 >, < 5 > for the second fuse block 150 , to allow current to flow depending on conditions of the fuses F 1 through F 4 . Here, if the fuse blocks 100 and 150 are employed in the redundancy circuit, the fuse blocks 100 and 150 are used to store an address of a unit cell of different banks.
[0011] An operation of identifying the condition of the fuses F 1 to F 4 of the first and the second fuse blocks 100 and 150 will be briefly discussed with reference to the circuit diagram of FIG. 1 a . In order to determine if a first fuse F 1 of the first fuse block 100 blows, a first fuse control signal <B> corresponding to the first fuse F 1 is activated such that current flows through a first control unit N 1 , wherein other fuse control signals <C>, <D> and <E> are inactivated (or not applied) such that current only flows along a path that passes through the first fuse F 1 . Next, the switching elements PT and NT are activated to connect the fuse with the power supply voltage VDD and the ground voltage VSS. If the first fuse F 1 is blown, current does not flow through the first fuse block 100 . Otherwise, current flows through the first fuse block 100 . In this manner, it is determined whether the first fuse F 1 is blown or not.
[0012] The four fuses F 1 to F 4 in the fuse blocks 100 and 150 form, two by two, a Y-shaped fuse pattern. Specifically, the first fuse block 100 includes a first fuse pair 110 and a second fuse pair 120 , each of which includes two adjacent fuses. The second block 150 includes a third fuse pair 160 and a fourth fuse pair 170 , each of which includes two adjacent fuses.
[0013] Referring to FIG. 1 b , the first through fourth fuse pairs 110 , 120 , 160 and 170 shown in FIG. 1 a are not arranged in parallel but are arranged to form a Y pattern or an upside down Y pattern, wherein the Y pattern and the upside down Y pattern are arranged alternating with one another. Such structure and arrangement may reduce the size of an area to be occupied by the fuse box. However, in the semiconductor is device having an increased integration density, it becomes difficult to form a diagonal line pattern of the Y-shaped pattern due to limitation of patterning techniques.
[0014] FIG. 2 is a picture demonstrating a problem of the fuse of FIGS. 1 a and 1 b.
[0015] As shown in FIG. 2 , a plurality of the fuses are arranged in a Y shaped pattern or an upside down Y shaped pattern and a portion of the diagonal lines of respective Y or upside down Y shaped patterns are damaged.
[0016] Specifically, when patterning the Y shaped fuse after an electrically conducting material is mounted, in case of a straight line pattern, it is easy to secure a manufacturing margin so that a required width of a designed pattern can be implemented. However, in case of a diagonal line pattern, if an exposure time is increased in order to secure the width of the pattern, the diagonal line pattern may be connected with adjacent patterns. Therefore, in order to avoid this, the Y shaped pattern is configured to have a thin width in contrast to the straight line pattern during a lithography process using a mask. When the fuse has a thin width, the resistance of the fuse is increased so that current flowing through the fuse may not be detected due to high resistance thereof, which causes an erroneous operation of the semiconductor device.
[0017] In addition, as the manufacture margin is reduced due to a high integration density, the diagonal line pattern having a thin width can be cut off. If the diagonal line pattern is cut off, the fuse becomes inoperable regardless of whether the straight line pattern blows. is Particularly, when the fuse used in the redundancy circuit of the semiconductor memory device is cut off, the semiconductor memory device cannot remember the address of the defective unit cell so that the defective unit cell cannot be repaired. In this case, the yield of the semiconductor memory device is greatly decreased.
BRIEF SUMMARY OF THE INVENTION
[0018] Embodiments of an embodiment of the present invention are directed to a fuse applicable to a highly integrated semiconductor device, which implements a fuse having a bar type pattern that forms a straight line instead of a pattern that is difficult to secure a manufacturing margin (for example, a crooked shape pattern or a diagonal line pattern), thereby preventing a defect from occurring during a manufacturing process of the semiconductor device so that a fuse having an increased reliability is provided.
[0019] According to an embodiment of the invention, a fuse block including a plurality of fuses comprises a plurality of first connection parts, each including a blowing area, a plurality of second connection parts, wherein the plurality of the second connection parts and the plurality of the corresponding first connection parts respectively form part of the fuse, and a common connection unit configured to electrically connect the plurality of the first connection parts and the plurality of the second connection parts.
[0020] In an embodiment of the invention, each first connection part and each second connection part are connected to one of a plurality of different terminals and one of a plurality of different voltage levels. The number of the second connection parts is 1 and more and N/2 and less when the number of the plurality of the first connection parts is N (N is a natural number). Also, the common connection unit is a shape of bar.
[0021] According to an embodiment of the invention, a semiconductor device includes a fuse block having a plurality of fuses that are electrically connected to one another; a control unit configured to control current flow through the plurality of the fuses included in the fuse block; and a determination unit configured to provide an output of the fuse block in response to a bank address.
[0022] Herein, the fuse block comprises a plurality of first connection parts, each of which including a blowing area, the plurality of the first connection parts being connected to a first voltage, a plurality of second connection parts connected to a second voltage; and a bar-type common connection unit configured to electrically couple the plurality of the first connection parts and the plurality of the second connection parts.
[0023] In one embodiment, a semiconductor device has first and second fuse blocks. Each fuse block includes a plurality of fuses sharing a common node, a plurality of control units, and a determination unit. Each control unit is coupled to a corresponding fuse in the plurality of the fuses and is configured to control current flow through the corresponding fuse according to a control signal, so that the plurality of the control units can output a fuse signal. The determination unit has a first input node configured to receive the fuse signal from the control units and a second input node configured to receive a bank address. The determination unit is configured to provide an output signal based on the fuse signal and the is bank address received. The first and second fuse blocks are coupled to each other at the common node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1 a and 1 b are respectively a circuit diagram and a plan view illustrating a fuse in a semiconductor device according to the related art.
[0025] FIG. 2 is a picture demonstrating a problem of the fuse of FIGS. 1 a and 1 b.
[0026] FIGS. 3 a and 3 b are respectively a circuit diagram and a plan view of a semiconductor device according to an embodiment of the present invention.
[0027] FIG. 4 is a conceptional view of a semiconductor device according to an embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0028] The present invention relates to a highly integrated semiconductor device having an increased reliability by increasing a manufacturing margin of a fuse block included in the semiconductor device, wherein the fuse block is used to selectively connect a plurality of terminals to one another and connect a plurality of voltages having different voltage levels to one another. In the following disclosure, for illustrative purposes, the fuse block is described to be included in a redundancy circuit for storing an address of a defective unit cell of the semiconductor memory device. Hereinafter, examplarly embodiments of the present invention are described in detail with reference to accompanying drawings.
[0029] FIGS. 3 a and 3 b are respectively a circuit diagram and a plan view of a semiconductor device according to an embodiment of the present invention.
[0030] Referring to FIG. 3 a , a first fuse block 300 and a second fuse block 350 respectively include a plurality of fuses F 1 through F 4 coupled between a power supply voltage VDD and a ground voltage VSS, switching elements PT and NT for controlling a coupling between the power supply voltage VDD and the ground voltage VSS based on a first control signal CTRL 1 and a second control signal CTRL 2 . Control units N 1 through N 4 are controlled by fuse control signals (<B>, <C>, <D>, <E> for the first fuse block 300 and < 2 >, < 3 >, < 4 >, < 5 > for the second fuse block 350 ) to allow current to flow depending on conditions of the fuses F 1 through F 4 . Determination units 330 and 380 are configured to output an output OUT of the fuses F 1 through F 4 in response to a bank address Bank_Address. Each of the first and the second fuse blocks 300 and 350 includes two pairs of the fuses, 310 and 320 for the first fuse block 300 and 360 and 370 for the second fuse block 350 . Here, for illustrative purposes, the first and the second fuse blocks 300 and 350 are described as those that are used in the redundancy circuit to store an address of a unit cell of different banks.
[0031] The determination units 330 and 380 are used to output the outputs OUT of the fuses F 1 through F 4 in response to the bank address Bank_Address. Similar to the semiconductor device according to the related art shown in FIG. 1 a , the first and the second fuse blocks 300 and 350 respectively include two pairs of fuses, 310 and 320 for the first fuse is block 300 and 360 and 370 for the second fuse block 350 . Here, for illustrative purposes, the first and the second fuse blocks 300 and 350 are described as those that are used in the redundancy circuit to store an address of a unit cell of different banks.
[0032] With reference to the circuit diagram of FIG. 3 a , it is described an operation of identifying the condition of the fuses F 1 through F 4 of the first and the second fuse blocks 300 and 350 . In order to determine if a first fuse F 1 of the first fuse block 300 is blown, a first control signal <B> corresponding to the first fuse F 1 is activated such that current flows through a first control unit N 1 , wherein other fuse control signals <C>, <D> and <E> are inactivated such that current only flows along a path that passes through the first fuse F 1 . Next, the switching elements PT and NT are activated to connect the fuse with the power supply voltage VDD and the ground voltage VSS. If the first fuse F 1 is blown, current does not flow through the first fuse block 300 . Otherwise, current flows through the first fuse block 300 . In this manner, it is determined whether the first fuse F 1 is blown. The determination units 330 and 380 performs a logic operation (e.g., AND logic operation) on an output value of current that is provided depending on whether the first fuse F 1 is blown and a logic value of the bank address Bank_Address. Then, the determination units 330 and 380 output the result of the logic operation.
[0033] Referring to FIG. 3 b , the plurality of the fuses F 1 through F 4 included in the two fuse blocks 300 , 350 shown in FIG. 3 a are not arranged to be parallel to one another but are configured to connect to each other at a central part to form a fuse block. Specifically, the fuse is block includes a first connection part 304 connected with a first power source that provides the power supply voltage VDD, wherein the first connection part 304 includes a blowing area, that is, the fuses F 1 through F 4 , a second connection part 306 that is connected between the ground voltage VSS and a second voltage, and a bar type common connection part 308 for connecting a plurality of the first connecting parts 304 and a plurality of the second connecting parts 306 .
[0034] Compared to a configuration of a conventional semiconductor device where a Y pattern is arranged alternatingly, the two fuse blocks 300 , 350 according to one example embodiment of the present invention are connected to each other through the common connection part 308 so that eight fuses included in the two fuse blocks 300 and 350 are electronically connected to one another. By using the common connection part 308 , the fuse block manufactured according to the present invention overcomes certain problems associated with a conventional fuse block having the Y pattern fuse, e.g., a width that is so thin in a diagonal line of the Y pattern such that the diagonal line fuse becomes weaker or even cut off. Therefore, when forming the fuse block, an increase in resistance or defects caused due to manufacture error can be prevented in advance so that a fixed to attempt (FTA) of the semiconductor device by using the fuses F 1 through F 4 can be increased.
[0035] In FIG. 3 b , it is described that the first and the second fuse blocks 300 and 350 shown in FIG. 3 a form a bar-type fuse block by connecting central parts of the first and the second fuse blocks 300 and 350 . However, it should be noted that the structure or arrangement of the is fuse block 300 or 350 can be modified in different embodiments. For example, when a plurality of the first connection parts 304 and a plurality of the second connection parts 306 are spaced apart from one another by a minimum required distance in consideration of a situation where fuse blowing occurs, the first connection parts 304 and the second connection parts 306 can be connected to respective sides of the common connection part 308 to be arranged in a straight row. Also, it is possible to reduce the number of the second connection part 306 that does not have a blowing area. In FIG. 3 b , there are eight first connection parts 304 and four second connection parts 306 , i.e., the first connection parts 304 and the second connection parts 306 form a ratio of 2:1 therebetween. However, the semiconductor device of FIG. 3 b is illustrated as an example, and the invention is not limited to that configuration. For example, only two connection parts 306 can be used in an alternative embodiment. In other words, if the number of the first connection part 304 that has a blowing area included in one fuse block 300 is N (N is a natural number), the number of the second connection part 306 that does not have the blowing area may be a 1 and more and N/2 and less.
[0036] FIG. 4 is a conceptional view of a semiconductor device using the fuse shown in FIGS. 3 a and 3 b according to an embodiment of the present invention.
[0037] As shown in FIG. 4 , the semiconductor device includes a plurality of bank blocks 410 , 420 , 430 and 440 , wherein each of the bank blocks 410 , 420 , 430 and 440 includes eight banks and four fuse circuits. For example, the bank block 410 includes eight banks Bank_ 0 through Bank_ 7 and four fuse circuits 400 A, 400 B, 400 C and 400 D. Each of the fuse circuits, for example, the fuse circuit 400 A is designed to remember an address of a defective unit cell that exists within two neighboring banks, for example, Bank_ 4 and Bank_ 0 among the eight banks Bank_ 0 through Bank_ 7 . The fuse circuit, e.g., 400 A, includes sixteen fuse blocks F 0 through F 15 , each of which has a structure substantially the same with a structure of the fuse block 300 shown in FIGS. 3 a and 3 b . Namely, when the address of the defective unit cell has 16 bits, the fuse block shown in FIG. 3 b remembers one bit of the address of the defective unit cell that exists within two neighboring banks and determines which bank has the defective unit cell by using a separate determination unit. Here, the 16 bits of the unit cell may include a 3-bit bank address, a 3-bit cell block address, and a 7-bit column address. The bit number of the address and the number of the fuse blocks to be included in the semiconductor device may vary according to the specifications of the semiconductor device.
[0038] As described above, when forming a fuse for use in a highly integrated semiconductor device according to the present invention, a manufacturing margin can be secured by modifying the shape of the pattern of the fuse block while utilizing a simple circuit such as a determination unit so that the semiconductor device performs a normal operation. Therefore, an additional process is not required. In this manner, the present invention can prevent a defect from occurring during a manufacturing process of the semiconductor device, thereby increasing is the reliability of the semiconductor device. Also, since the fuse box formed according to the present invention has a bar type pattern, which is easy to manufacture, the fuse box has a relatively low cost for both design and manufacturing.
[0039] It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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The invention relates to a semiconductor device comprising a fuse that is implemented as a bar type pattern that forms a straight line instead of a pattern that is difficult to secure a manufacturing margin. A fuse block including a plurality of fuses comprises a plurality of first connection parts, each including a blowing area, a plurality of second connection parts, wherein the plurality of the second connection parts and the plurality of the corresponding first connection parts respectively form part of the fuse, and a common connection unit configured to electrically connect the plurality of the first connection parts and the plurality of the second connection parts.
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The present invention relates to vaginal tampons and more particularly to tampons which may be inserted in a sterile manner.
BACKGROUND OF THE INVENTION
A newly recognized illness of women called toxic shock syndrome has recently been reported. (FDA Bulletin July 1980). Toxic shock syndrome generally occurs during the menstrual period and appears to be associated with the use of tampons which carry bacteria into the inner regions of the vagina close to the uterus where the menstrual fluid provides a good growth medium for bacteria. Staphylococcus aureous is almost always found to be present in toxic shock syndrome. The mortality rate of women who experience toxic shock syndrome is between three and ten percent.
Tampons which are commonly about one and one-half inches long are inserted into the vagina beyond the constricting muscles, generally about two inches. A tampon may be inserted into the vagina with a pusher, such as a stick removably attached to the outer or trailing end of the tampon, or may be encased in a plastic applicator which is inserted into the vagina and from which the tampon is pushed and ejected. In either case, a portion of the tampon or applicator which is inserted into the vagina will likely be touched by the user's hand and/or will be exposed to the external vagina during insertion and contaminated thereby, whereby bacteria and viruses, capable of causing toxic shock or other uterine or vaginal infections, are carried deep into the vagina.
SUMMARY OF THE INVENTION
A tampon assembly for sterile insertion of a tampon into the vagina has a semirigid insertion tube, containing the tampon, telescoped inside a semirigid guide tube having a flexible sheath secured to its inner end which is tucked back into the insertion tube. The user aligns the assembly with the vaginal canal and plunges the insertion tube inward of the guide tube so that a portion of the insertion tube enters the vagina while the flexible sheath extends to sheathe the portion of the insertion tube within the vagina. Thereafter, a pusher is used to eject the tampon from the insertion tube to locate the tampon in the vagina beyond the constricting muscles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of a tampon assembly embodying various features of the present invention, the assembly shown in its pre-insertion position.
FIG. 2 is a cross-sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a cross-sectional view similar to FIG. 2 showing the tampon assembly in its insertion position.
FIG. 4 is a cross-sectional view of the assembly taken along line 4--4 of FIG. 2.
FIG. 5 is an exploded perspective view of the tampon assembly.
FIGS. 6a-c illustrate the insertion of the tampon into the vagina, FIG. 6a showing the assembly being placed against the introitus, FIG. 6b showing the inside insertion tube plunged fully into the outside guide tube, and FIG. 6c showing the tampon ejected from the inside tube into the vagina beyond the constricting muscles thereof.
FIG. 7 is an elevation view, partially cut away, of an alternative embodiment of the present invention in which an enclosed wrap maintains the sterility of the outer end of the assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the present invention, a tampon assembly 10 has a tampon 12 (FIG. 2) and a container 13 including a semirigid inside insertion tube 14 which carries the tampon and which is telescoped in a semirigid outside guide tube 16 having a sterile flexible sheath 18 secured to an end 20 thereof and tucked into the insertion tube so that when the assembly is placed agaist the introitus A (FIG. 3) of the vagina B and the insertion tube is plunged inward of the guide tube and into the vagina, the flexible sheath extends to sheathe that portion of the insertion tube in the vagina, thereby providing sterile insertion of the tampon. An ejector means or pusher 22 is used to eject the tampon 12 from the insertion tube 14 into the vagina beyond the constricting muscles C.
So that the invention may be more fully understood, the tampon assembly 10 will now be described in greater detail. To facilitate discussion, the ends of the assembly 10 and members thereof which are directed toward the body will be described as the inner ends.
The vaginal tampon 12 is of conventional design, being formed of compressed fibrous material and having a pointed inner end 24 to ease its insertion and having a withdrawal cord 26 secured to its outer end 28 which extends from the inserted tampon outward of the introitus A where it may be pulled to remove the used tampon from the vagina B. The tampon 12 itself does not constitute a part of this invention, and variations of tampon design known to those skilled in the art may be made without departing from the scope of the present invention.
The insertion tube 14 is cylindrical and is sufficiently narrow, e.g., about one-half inch in diameter, that it may be inserted into the vaginal canal D. The compressed tampon 12 bulges against the wall of the insertion tube 14 and is thereby held in position. The insertion tube 14 is preferably semirigid, having sufficient rigidity to part the walls of the vaginal canal D as it is plunged therethrough, but sufficiently flexible to deform and prevent injury should it be inserted incorrectly and pushed against sensitive tissue. A flange 30 around the outer end 32 of the insertion tube 14 serves as a stop which abuts the outer end 34 of the guide tube 16 when the insertion tube 14 is plunged inward as shown in FIGS. 3 and 6b.
The guide tube 16 is similarly cylindrical with an inside diameter substantially equal to the outside diameter of the insertion tube 14 and is movably telescoped therearound. Preferably, the guide tube 16 fits tightly around the insertion tube 14 and frictionally maintains the tubes in telescoping relationship to each other without slipping apart prior to use. The guide tube 16, like the insertion tube 14, is preferably semirigid and generally is formed of the same material; however, the guide tube may be thicker and less flexible as it is not intended that it be inserted into the body. Preferably, both semirigid tubes 14, 16 will be formed of a polymer which will degrade in water so that the tubes may be flushed down the toilet.
The guide tube 16 is shorter than the insertion tube 14, so that when plunged into the vagina B, the insertion tube is displaced between about 11/2 to 2 inches as it is moved from its pre-insertion position (FIG. 1) with its inner end 36 generally flush with the inner end 20 of the guide tube 16 to its insertion position (FIG. 2) with its outer end 32 generally adjacent the outer end 34 of the guide tube.
A flange 38 (FIGS. 2, 3), disposed around the inner end 20 of the guide tube 16 for placement against the introitus A, helps to prevent the guide tube from penetrating the vagina B. The outside diameter of the flange 38 is preferably at least 3/4 inch in diameter.
The flexible sheath 18 is preferably formed of thin elastomeric material, such as silicone rubber, and has a diameter slightly greater than the outside diameter of the insertion tube 14 to form a loose sheath therearound in the inserted position. A thickened elastomeric band 40 at the inner end of the flexible sheath 18 is pulled over the flange 38 at the inner end 20 of the guide tube 16 where it binds around the guide tube and is prevented by the flange from slipping off during tampon insertion. The flexible sheath 18 is folded from its outer end, around the inner ends 20, 36 of the semirigid tubes 14, 16 and into the insertion tube inward of the tampon 12. The flexible sheath 18 is generally equal in length to the difference in length of the insertion and guide tubes so that the portion of the insertion tube 14 which is plunged into the vagina B is at all times fully sheathed by the flexible sheath 18. The exterior surface of the flexible sheath 18 may be lubricated to facilitate its insertion.
The pusher 22 has an applicator stick 48 having an inner end which impales the outer end of the tampon 12 to removably attach the stick thereto. The outer end may be attached to an optional crosspiece 50. The stick 48 is somewhat longer than the insertion tube 14, so that when the user plunges the pusher 22 completely inward, the tampon 12 is ejected from the inner end 36 of the insertion tube. The crosspiece 50 is longer than the inside diameter of the insertion tube 14 and stops inward movement of the pusher 22 when it abuts the outer end 32 of the insertion tube, thereby preventing the pusher from accidentally being inserted in the vagina.
The tampon assembly 10 is assembled under sterile conditions and packaged in a sterile wrapper (not shown) with the assembly in its pre-insertion position. The wrapper preferably is designed to be opened so that the user will grasp the outer end first and not contaminate the inner end to which the flexible sheath 18 is attached.
Grasping the assembly 10 with her left thumb and two fingers, the use will align the assembly with her vaginal passageway as may be described in accompanying directions, and shown in FIG. 6a. She places the assembly 10 with the flange 38 against her introitus A and plunges the insertion tube 14 through the guide tube 16 and into the vagina B as far as it will go with fingers of her right hand as shown in FIG. 6b. As the insertion tube 14 is plunged inward, the flexible sheath 18 is pulled over the inner end 32 of the insertion tube and extends along the exterior thereof. The loosely fitting flexible sheath 18 is held along the exterior of the insertion tube 14 by the conforming walls of the vaginal passageway. When the insertion tube 14 is plunged fully into the guide tube 16, the flexible sheath 18 is substantially fully extended and removed from the insertion tube and permits passage of the tampon 12 through its open inner end. Thereafter, the user plunges the pusher 22 fully inward (FIG. 6c) until the crosspiece 50 abuts the outer end 30 of the insertion tube 16.
The ejected tampon 12 is fully beyond the constricting muscles C of the vaginal canal D and the user removes the assembly applicator members by pulling the exposed guide tube 16 outward. The abutment of the outer end 34 of the guide tube 16 against the flange 30 of the insertion tube 14 and the abutment of the outer end 32 of the insertion tube against the crosspiece 50 of the pusher 22 causes the insertion tube and the pusher to follow the guide tube as it is pulled away from the introitus A. A slight pull on the loosely held pusher 22 dislocates it from the outer end 28 of the tampon 12. The flexible sheath 18 is also pulled along with the guide tube 16. The withdrawal of the applicator apparatus helps to pull the end of the withdrawal cord 26 outward so that it protrudes from the introitus A. With a slight tug on the withdrawal cord 26 the user may position the tampon 12 in the inner end of her constricting muscles C.
Illustrated in FIG. 7 is an alternative embodiment of the tampon assembly 10', in which a flexible enclosure 60 protects the outer end of the assembly from contamination. The enclosure 60 is secured at one end around the outer end 32 of the insertion tube 14 and at the other end around the pusher 22 to maintain the sterility of the outer end of the tampon 12 and that portion of the pusher 22 which enters the vagina B. The enclosure 60 shown in FIG. 7 has an elastomeric end band 62 around the insertion tube 14 and an elastomeric end band 64 around the pusher 22. As the pusher 22 is plunged inward, the enclosure 60 folds up. Alternatively, a suitable enclosure for the outer end of the assembly 10 may be formed of paper and attached by an adhesive to the pusher 22 and insertion tube 14.
While the invention has been described in terms of specific preferred embodiments, modifications obvious to one with ordinary skill in the art may be made without departing from the scope of the invention. For example, instead of a stick type pusher, the pusher may be a third semirigid tube which telescopes inside of the insertion tube. Grooved rings around the guide tube may be provided to facilitate grasping thereof. Because tampons may be shelved for several years before use, an elastomeric band maintained in a stretched position over a long time may lose resiliency. Accordingly, to insure that the flexible sheath will not slip off during insertion, it may be desirable to permanently affix the sheath to the guide tube by gluing, welding, etc.
The telescoping arrangement of two tubes, in the desribed preferred embodiments, provides guidance for the tampon through the vaginal canal. The sterility of tampon insertion may, however, be maintained in a simpler arrangement in which the tampon is contained in a single tube having a flexible sheath attached to its outer end and tucked back into the tube. The tube is placed against the introitus, and the tampon is ejected therefrom through he vaginal canal. As the tampon is ejected, it extends the sheath which provides a sterile passageway through the vaginal canal for the tampon.
The concept of the present invention in which an inside tube is plunged through a telescoping outside tube with a sterile flexible sleeve attached to its inner end may have other medical applications. Examples of alternative applications of the invention principle include catheterizations, including catheterizations of the cerebral ventricles, peritoneoscopy where instruments are inserted through the tubes, and abortions where the uterine cavity may be entered through the cervix in a sterile fashion to deposit an abortifacient.
Various features of the invention are set forth in the following claims.
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A tampon assembly includes a tampon and a withdrawal cord, an insertion tube containing the tampon, a guide tube telescoped around the insertion tube, a flexible sheath attached to the inner end of the guide tube and tucked into the inner end of the insertion tube, and a pusher to eject the tampon from the insertion tube. When the user inserts the tampon by placing the guide tube against her introitus, plunging the insertion tube inward so that a portion thereof penetrates the vagina and plunging the pusher inward to eject the tampon from the insertion tube, the flexible sheath sheathes the penetrating portion of the insertion tube thereby maintaining the sterility of the insertion.
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FIELD OF THE INVENTION
This invention relates to the automatic tallying of uniquely serialized oil field tubulars as they enter or are withdrawn from well bore service and the application of these tallies to service records and down hole depth monitoring.
BACKGROUND OF THE INVENTION
In the oil industry drilling, completion or working-over of wells, drill or tubing strings are used to physically enter and enable performance of desired work functions down hole. In drilling operations drill strings are generally categorized as drill stem or drill pipe and bottom hole assemblies. Drill pipe joint lengths vary in the range of 30 feet and are connected together by "tool joints" having a "box", or female thread on the upper end, and a "pin" or male thread on the down-hole end. Tool joints are commonly an "integral" type attached to the drill pipe by a friction or flash weld. A large drilling rig for deep drilling may have drill pipe sections in excess of 500 or 600 joints. Drill pipe makes up the principal length and investment of a given drill string.
Bottom hole assemblies represent a lesser overall footage of the drill string and are thick walled approximate 30 foot long tubular sections called "drill collars." Drill collars provide weight to be run on drill bits. Drill collars have larger and more rugged box and pin connections than drill pipe and the threads of these connections are machined from the body of the drill collar itself. Bottom hole assemblies may include various "subs" of relatively short length for crossover between dissimilar thread sizes or forms as between drill pipe and drill collars. Other subs might include bit subs for adapting a bit thread to a drill collar, stabilizer subs serve to center drill collars in the well bore and safety valves
A square or hexagonal cross section "kelly" passing through a roller kelly drive bushing seated in the rotary table serves to impart rotation to the drill string in the hole. A kelly saver sub is customarily screwed onto the lower end of the kelly and provides a wear thread for the repeated make and break of the kelly when adding drill pipe when drilling. Many offshore rigs now use a "top drive" in lieu of the rotary table and kelly while drilling and drill down an entire "stand" of three joints of drill pipe before a new connection is required.
The hole depths at which the bit is drilling or other types of down hole work is being conducted is presently determined by measurements taken by rig crewmen with a steel tape and are hand written and totaled by the driller in his tally book. In the case of drilling, these tallies are usually broken down by bottom hole assemblies, drill pipe and the amount of footage the kelly is in the hole using as a reference point, or datum, the top of the kelly drive bushing or top of the rotary table as zero elevation. The total of these three general categorizations therefore provides hole depth.
During normal drilling procedures, individual drill pipe joints, subs or drill collars are measured immediately prior to picking up for insertion in the well bore string. Similarly, joints are measured when laid down as to be later picked up or to be replaced by other drill string components. Over only short periods of time, errors invariably occur which are usually the cause of inadvertently omitting entries into the tally, arithmetic errors or incorrect measurements made or reported by crewmen. To check measured depth tallies, the common practice is to measure and tally each three joint stand stood back in the derrick when tripping out of the hole to replace a bit or other down hole tool. This tally of approximate 90 foot stands, including bottom hole assembly stands, is used as a check of depths and serves to check and correct faulted tallies.
Due to tally errors being common, it is normal good practice to maintain a count of total joints of drill pipe on a rig when drilling starts and when drilling has progressed, occasionally reconciling a count of tallied joints in the hole and joints on the pipe rack with the original inventory. Hole depth is critical for geological reference and for operations such as when casing a hole in order to establish the amount of casing required to be landed at the correct depth. For these reasons, accurate pipe tallies of both joint quantities and total lengths are important and much expensive rig time is spent checking and rechecking such tallies.
Drill stem retirement from service is frequently necessitated by wear on the outside diameters of pipe, tool joints and drill collars which reduces wall area and both tensile and torsional load capacity; excessive corrosion or erosion; and physical damage from poor handling practice. Also of concern is the potential development of cracks or complete failure due to stress and fatigue especially in corroded, worn and thinner walled pipe.
Drill pipe life has traditionally been evaluated in terms of total feet of hole drilled by the composite several hundred joints that make up a given string of pipe. Service life of bottom hole assembly components is usually limited by outside diameter wear or from the repeated re-machining connection threads to eventually cause too short an overall length for handling by the derrick man in the derrick. Therefore drill collar or bottom hole assembly service factor measurements, such as cumulative footage drilled or fatigue damage, may not be generally as important as for drill pipe.
Although an identification serial number may be stenciled on each joint in a non-wear area, it is virtually impossible for field crews to keep track of individual joint usage whereby the total footage each joint drills may be manually recorded and accumulated. For this reason down hole service and wear is not evenly distributed to each individual joint of an entire drill string and some joints invariably receive much greater service than others. Equalizing service presents even more difficult problems if a portion of a drill string is lost in the hole and new pipe is added and indistinguishably mixed into an existing string.
Disproportionate down hole service may often be recognized by outside diameter wear but all too frequently, particularly in deviated holes, fatigue damage may become a deciding factor in the decision to retire drill pipe. Present day drill pipe inspection methods are capable of measuring wall wear or the extent of internal pitting but can only detect fatigue in the form of cracks already initiated in service. When a few cracks begin to appear in successive routine inspections, it is currently necessary to assume every joint in the string has been subjected to identical fatigue damage and the entire string requires retirement from service.
SUMMARY OF THE INVENTION
This invention provides a means of automatically tallying and maintaining a inventory of oil rig drill stem components within the well bore. Uniquely serialized electronic identification, or transponder, tags contained by individual drill string components are recognized by an antenna and reader system as they pass through the rig floor. The uniquely serialized identification code accesses a computer data base to recall individual component information. Footage lengths of recalled in-hole components are maintained in a tally to provide a location of the components within the hole and a summation of total lengths is applied for hole depth and drill tool or bit depth determinations.
Down hole service factors indicative of component wear and useful life are also measured and computed for cumulative recording to the individually serialized components tallied in the well bore. These individual drill string component service factors include footage of hole drilled by each identified drill string component rather than the total hole drilled by the entire composite string during its useful life. Another service factor hitherto not practical to record during the useful life of each individual drill string component is the cumulative total rotations experienced during drilling or reaming. An estimate of fatigue wear, or damage, experienced by drill pipe joints rotating through abrupt hole curvatures, or "dog legs", may also be automatically computed. Fractions or percentages of fatigue life expended due to fatigue damage may be accumulated for each identified component. An additional feature of the invention is the tracking of individual components through floating drill rig sub-sea blowout preventer stacks so as to avoid attempting to seal off abnormal pressures by closing the preventers around odd size component diameters.
This invention enables grading components according to various service factors including footage of hole drilled, rotations and fatigue damage. Selection of components for down hole service may then be made to remove excessively worn joints or to better distribute equivalent service to each joint in a drill string. Equalization of service factors amongst each joint of a drill string will result in lengthened composite string life. Intervals for routine and expensive component inspections may also be extended with improved service factor equalization.
Identification is accomplished by means of uniquely coded radio frequency (RF) frequency electronic identification tags individually and protectively affixed to each component. Drill mud and earth formation material accumulations are very poor conductors of RF electromagnetic signals and severely restrict read distances between tag and the reader antenna. Electronic tags have been used to a limited extent in oil rig equipment identification including drill stem. However, their use has been hampered by short read distances further limited by contaminants encountered on the rig or in the well bore.
A preferred embodiment of my invention provides a means of tag mounting in drill string components in which tags are encapsulated in an electromagnetically conductive plastic type material. The plastic type material essentially fills the tag mounting recess in the component and provides an external surface flush with the outer surface of the mounting recess therby eliminating depressions or cavities which collect deposits of mud or formation materials. As the outside diameter of the component contacts the well bore walls while moving in the hole, the component is continually wiped of deposits which cause tag communication signal attenuation. As the component outside diameter wears in the hole, sacrificial material of the tag encapsulation will wear at a similar rate and maintain the smooth outside diameter. This feature of the invention significantly improves read distance between tag and reader as compared to a tag mounting in a recess which allows mud and formation deposition.
Electronic identification tag manufacturers have developed tag, antenna and reader systems operating on RF frequencies approved by the FCC for industrial, scientific and medical (ISM) applications. Destron-IDI of 2542 Central Avenue, Boulder, CO 80301 offer tags in a kilohertz frequency ranges. These tags have a maximum read distance limited to approximately one foot in clean conditions and are used for fish, animal and manufacturing process identification. A 915 Mhz ISM frequency system is extensively used in vehicle toll road collection and railroad car identification. Amtech Corporation, 17403 Preston Road, Dallas, TX 75252, is a major developer and supplier of tags, antennae and reader systems for this type application. Although the 915 Mhz has a more than adequate clean environment read range, minute films of drill mud or other drill rig contaminants restrict transmission of electromagnetic signals between reader and tags to the extent this frequency is not possible for this invention.
My invention anticipates the use of an ISM allocated RF frequency within the 125 Khz to 100 Mhz range, and more specifically, a preferred frequency of 27.1 Mhz. The tags of this frequency provide an adequate read distance for the requirements of this invention. A tag, reader and antenna in the 27,1 Mhz frequency range has been developed for another type application by Integrated Silicon Devices Pty. Ltd., 99 Frome Street, Adelaide, S.A. 5000, Australia. However, it is intended this invention not be limited only to the specific and preferred 27.1 Mhz frequency. dr
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically a drill rig derrick with the traveling block suspending the swivel, kelly and drill string.
FIG. 2 shows a drill collar with subs and bit which constitute the components of a typical bottom hole assembly. Drill pipe then completes the drill string up the hole to the rig.
FIG. 3 is a partial section of the pin end of a drill pipe tool joint showing an identification tag in a recess and retained by a plug.
FIG. 4 shows a block flow diagram typical of the reader and computer system.
FIG. 5 shows a basic data acquisition and flow diagram for the computer system.
FIG. 6 schematically illustrates a sub-sea blowout preventer stack on the sea floor below a floating drill vessel which has drifted off the hole center.
FIG. 7 shows a drill rig in which measurements are made to correct locations of tallied and tracked components.
FIG. 8 shows a drill string fatigue curve, without axial tension.
FIG. 9 shows a drill string fatigue curve, with axial tension.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, traveling block 8, reeved with crown block 36 in the drill rig derrick, is shown suspending swivel 10. The swivel is screwed into hexagonal or square drive kelly joint 12 with kelly drive bushing 14 riding on the drive flat shoulder on the lower end of the kelly. The kelly saver sub 16 is screwed into the kelly joint pin 18 and, in turn, the saver sub pin is screwed into the tool joint box 20 of drill pipe joint 22. Uniquely coded electronic identification tags 24 are shown recessed in the pin end of drill string components 12, 16 and 22. The drill pipe extends through the rotary table 26, through the identification tag reader antenna 28 and into the well bore through bell nipple 30 mounted on top of the blowout preventer stack 32. Antenna 28 is preferably positioned just below the rotary table and its elevation is known. The illustrated position of the traveling block in the derrick with a single joint of drill pipe made up in the kelly saver sub is characteristic of having just made a connection of an additional pipe joint and prior to lowering the drill string to engage the kelly drive bushing in the rotary table to turn the drill string and recommence drilling.
Still referring to FIG. 1, interface sensor 101 may be supported from the frame beams of crown block 36 and measures rotation of fast line sheave 101B. Sensor signals are computer translated into traveling block vertical travel with consideration of the number of lines strung between the blocks having been manually keyed in the computer. Through knowledge of the sheave pitch diameter for the wire line passing over the fast line sheave, the footage of wire line used to either hoist or lower the traveling block 8 is computed with input from sensor 101 of sheave revolutions or fractions thereof. Fast line footage divided by the number of lines reeved between the blocks will equal the footage of travelling block travel. This sensor may include small magnets 101A positioned around fast line sheave 101B and magnetic switches actuated by the proximate passing of the magnets. Interface sensor 102 may also employ proximity switches for counting revolutions of the rotary table 26 and drill stem when drilling or reaming. Deadline anchor 34 commonly supported on the derrick floor employs a hydraulic load cell for measuring weight suspended by the traveling block and interface 103 uses a pressure transducer for transmitting this measurement to the computer. These interface units are commercially available from Oilfield Instruments, Inc., 17923 Fireside Drive, Spring, Texas, 77379.
Referring now to FIG. 2, additional drill string components are shown as might typically be located at the bottom of the hole. Drill pipe 22 is connected to other pipe joints up the hole by tool joint 38 consisting of box 20 and pin 40. The drill pipe tool joint pin is made up in the box of crossover sub 42. The crossover sub pin in turn is screwed into the drill collar 44. Although but one drill collar is shown, there are ordinarily multiple collars in the hole. The drill collar is shown screwed into a bit sub 46 and the drill bit 48 is made up in the bit sub. The components 42, 44 and 46 are conventional and are referred to as the bottom hole assembly. Note that drill stem boxes are up and pin threads are on the lower end of a component. Few exceptions to this general rule occur and are primarily in bottom hole assemblies.
My novel well component identification tag assembly is shown in FIG. 3. A segment of a drill pipe tool joint has been cut away to illustrate the identification tag 24 in a protective recess 50 in the tool joint pin. These identification tags receive an electromagnetic signal from the reader antenna 28 by means of the tag's own internal antenna. The energy derived from the reader transmission is sufficient to enable the tag to re-transmit a uniquely coded binary signal back to the reader. The identification tag 24 is held and retained in place by a plastic type plug 52 which is conductive to electromagnetic signals. The plugs may be bound, pressed, threaded, cast and hardened in place or otherwise secured in the recess. The plugs serve the primary and key function of keeping formation clays, cuttings or drill fluids from accumulating over the tag antenna and attenuating the electromagnetic communication signals between the tag and reader. These plugs are installed flush with the outside diameter of the component in which a tag is mounted and provides a sacrificial wear surface remaining smooth with the outside diameter of the tool joint or component as it wears in the hole. An additional advantage of the plug is in buffering and protecting the tag from handling on the rig or from in-hole damage.
Referring now to FIG. 4, a block diagram of a typical information or data flow method of the system illustrates the reader 109 with antenna 28 transmitting an electromagnetic energizing signal to identification tag 24 and a coded identification response being returned to the reader by the tag. The antenna is connected to the reader by means of suitable wiring or cable and the reader may be remotely located or housed with the computer 106. Various developers and manufacturers of electronic identification tags and readers are available offering several different technological approaches to reader and tag transponder electronics. For instance, the identification tag may respond with a modulated excitation signal to provide the binary identification code or the tag might contain an oscillator energized by the reader excitation transmission enabling a coded response on a different electromagnetic frequency.
Still referring to FIG. 4, the interfaces from rig equipment are shown; sensor 101 providing the computer information regarding the direction and travel distance of the traveling block; a rotary table rotation sensor 102 for counting revolutions, or in the case of a top drive, a revolution counter sensor at the top drive mechanism; and weight indicator sensor 103 to provide information regarding the weight suspended from the traveling block. Interface sensors 104 and 105 are described later. The keyboard 107 permits manual entry into the computer 106 of drill string serial numbers and physical information to the data base related to identification tag coding; untagged component lengths and physical data which are to be included in a tally; datum elevation measurements from the reader antenna elevation; well bore inclination and direction survey readings with depth interval; selection of desired display or print-out; the number of lines reeved to the traveling block; the traveling block suspended weight, or load, setting which activates travel distance and direction into depth computations; and sub-sea blowout preventer seal elevations. The visual display 110 may be by means of a CRT or LCD screens.
As the drill string passes through the drill floor, reader 109 by means of antenna 28 transmits and receives electromagnetic signals to identify tagged components. Tag coding accesses the unique data base record to recall component length and features. This tally is maintained in a computer data element as an inventory by component type and tallied length and tally summations. Appropriate adjustments by the computer are made for block travel and correction from antenna to datum elevations. By means of visual display 110 to the driller, tallied and computed depth determination may be categorized similar to a common form as in the drillers hand kept records. Driller records are normally separated into feet of kelly in the hole, drill pipe joint quantity and total length and bottom hole assembly component quantity and total length. The total footage of these categories when drilling represent total well depth to the driller which will be retained by the computer for display when the string is hoisted off bottom. A like procedure is followed in the case of top drive substitution for the swivel and kelly except that feet of pipe of the last identified joint will be recorded into the hole rather than kelly footage.
An additional feature of the invention as shown in FIG. 4 is a battery powered hand held reader 108 with memory means capable of identifying components on the pipe rack or in remote locations. This inventory data may be communicated with the main computer Identification remote from the drill floor is desirable for the grading, selection and sorting for improved service factor equalization among all components of a composite drill string. An umbilically attached reader is also a feature of the invention and may be substituted for a battery powered unit when the computer system is sufficiently nearby.
Referring now to FIG. 5, a basic data acquisition and flow diagram within the computer system shows data acquisition from reader and sensors contained in the Read block 112. The Accept Keyboard Overrides 114 is intended for keyboard input of various data as so described elsewhere in this description of the preferred embodiments. The Compute Update Values 116 provides tally totalization, service factor computation and other like calculations for the Update Data Base 118 segment of the flow diagram. Visual or printed results of such computations or keyboard override instructions is represented by the Update Display 120 block. Other off-line features include data reporting and portable hand reader inventory monitoring.
Referring again to FIG. 1, to illustrate an example in which bit depth and total depth may be determined by the system computer, consider the traveling block 8 supporting swivel 10 and kelly 12 has drilled down maximum kelly travel to the top of the kelly drive bushing 14 in the rotary table 26. Pipe and bottom hole assembly tally totalization is combined with kelly travel which is measured by means of block travel sensor 101 activated into depth computations by a sufficient suspended weight detected by means of sensor 103. When drilling new hole, these summations establish the current total depth for driller display. When the drill string is hoisted off bottom, as for the purpose of adding an additional pipe joint for drilling deeper, a negative block travel distance is activated into bit depth calculation. The block with swivel and kelly lifts the string to where the upper-most tool joint box 20 may be suspended in the rotary table by means of drill pipe slips. The connection between the kelly saver sub 16 and the pipe tool joint box is broken, the kelly lifted out of the box and lowered for make up into the box of the drill pipe joint located in the "mouse hole" 54. As block suspended weight with only the swivel, kelly and a single joint is not sufficient to trigger incorporation of block travel distance into tally calculations, the new connection is hoisted out of the mouse hole by the kelly with no change in bit depth and made up into the joint supported by slips in the rotary table. On picking up the entire string from the slips, drill string weight is adequate to cause block travel to be included in bit depth computation and the entire assembly appears as shown in FIG. 1.
As the string is then lowered, the newly added section with tool joint pin 40 containing identification tag 24 is recognized passing reader antenna 28. The reader provides a unique coding to the computer which recalls from the data bank the newly identified joint's length and incorporates it with the tally of in-hole components but does not yet include the new joint footage in the totals. Were the newly picked up joint to be added forthrightly, summation of the new joint length into total tallied footage will provide an erroneous and excessive bit depth as most of the new joint footage is in the derrick and not yet in the well bore below datum elevation. A datum elevation representing top of kelly drive bushing (KDB) or top of the rotary table is ordinarily used when drilling with a kelly. Assuming a KDB reference datum, the bit depth computation will provide a footage equaling the antenna to KDB measurement plus the previously tallied component totals of footage in the hole and plus lowering traveling block distance.
As lowering block travel adds to bit depth, the kelly saver sub is next identified. With new tag recognition, the newly picked up joint actual data base measured length is added in the tallied length totals as a replacement for the block travel measurement. Any error in block travel measurement may thereby be corrected. When the kelly pin 18 is identified with continued lowering of the traveling block the same process replaces measured travel with data base actual measurement of the saver sub. The footage of kelly in the hole is thereafter measured by means of block travel and totaled into bit depth until such time as the bit reaches the well bore bottom and the bit depth display thereafter equals the total depth display as drilling new hole recommences.
In the case of a top drive, the same general procedure is followed except that neither the kelly, the kelly drive bushing or mouse hole is used and an entire three joint stand 56 as shown in FIG. 1 is connected in the derrick by the top drive from the stand stood back position. With the kelly and kelly drive bushing not used, the conventional swivel is replaced by a motor driven swivel suspended by the traveling block. This powered swivel is known as a top drive. With no kelly drive bushing, reference datum elevation of top of rotary is desired. When the lower-most joint tag of a stand 56 is identified by the reader and processed in the computer in a like manner to that used with the kelly lowering a newly picked up single joint into the hole. However, the distance between the reader antenna and top of rotary is substituted for the KDB datum. This process is then repeated for the next two joints of the stand as deeper drilling progresses.
As the drill string is hoisted, or as a trip out of the hole is made and pipe withdrawn from the well, the tally is adjusted through block travel and reader identification of withdrawn components and bit depth is displayed. When tripping in the hole, the tally of pipe and bottom hole assembly provides the bit depth in a computation also utilizing the block travel and weight interface inputs. As in making connections either with a kelly or with a top drive, block travel is recorded into depth computation only when the weight indicator interface setting in the computer is exceeded.
A computer comparison of block travel distance to successive reader identified tag tallies will serve as a check against insertion in the string of untagged components not properly keyed in the tally record. This check may also reveal a possible tag malfunction so the faulty tag can be replaced and the identification code of the new tag re-identified with a stenciled serial on the component. When block travel does not match identified contiguous component tally combinations, an error will be noted in the tally record and an audible signal notifies the driller of the tally discrepancy.
When a tally display or print out by each individual section of drill stem either in the hole or as to be stood back in the derrick during a trip is desired, such display for the driller may be as subassemblies of three joints, or stands. On trips out of the hole, this is for such purposes as easy driller identification of the stage he is at on a trip; locating components to be changed out or relocated; changing thread breaks from the last trip to check for possible dry or leaking connections; and anticipating the method drill collar stands will be stood back in the derrick for handling convenience.
An additional feature of the invention is the capability to compute and record various service factors which serve as a measure of wear and useful service life of a drill string and its components. One such embodiment is the service parameter represented by the total footage drilled by each drill string component. Total cumulative footage drilled by individual component may be determined by the computer utilizing the tally of pipe in the hole and the recording of footage drilled during the interval each identified component is in well bore service.
Another embodiment of the invention is the measurement of a drill string service factor represented by the cumulative total count of revolutions imposed on each tagged component while drilling or reaming. This count is provided through an interface with a rotation sensor 102 of FIG. 1 mounted on the rotary table or top drive. The count will be activated from drill string rotation and recorded to each individual component present in the well bore.
An additional embodiment of the invention is a system for automatically determining and recording to a cumulative service data element an estimation of fatigue damage experienced by tagged and tracked drill pipe joints rotating through relatively sharp well bore curvatures. The curvatures, or dog legs, that may cause fatigue damage occur in "straight" or non-directional holes but are commonly present in directionally drilled holes. Dog leg curvatures are measured in terms of the change in degrees of angle per 100 feet of hole. This change is actually the change in overall angle produced by a change in inclination as well as a change in direction as from a compass heading. For the location of these curvatures, surveys are commonly taken at various depth intervals and in problem straight hole areas, as in directional drilling, may be run every thirty feet or less of hole drilled.
The system computer calculates overall changes in hole angle from keyboard entry of depth, hole inclination and direction in directional holes. Only the change of inclination is entered if straight hole is being drilled and directional information is not provided by the survey instrument. Dog leg severity is computed to provide degrees per 100 foot of overall angle change. This calculation is by means of solid geometry and trigonometry. Equations for calculation of dog leg severity have been derived by several sources, one of which was by Arthur Lubinski, then of Stanolind Oil and Gas Company, and presented in his paper entitled "Chart for Determination of Hole Curvature (Dog Leg Severity)". This paper was presented to the American Petroleum Institute Mid-Continent District Study Committee on Straight Hole Drilling on Oct. 31, 1956.
To ascertain dog leg reverse bending stresses which occur to cause component fatigue damage, the computer calculates the bending stress imposed by hole curvature. As shown in the following equations, bending stress calculations consider the "effective tension" occasioned by the weight of the drill string suspended below the curvature interval by the drill pipe in the dog leg and a buoyancy factor. The general equation for determination of bending stress may be stated as: ##EQU1## In field units, this equation becomes: ##EQU2## in which: O b =unit bending stress, psi
c=hole curvature, degrees per 100 feet
E=modulus of elasticity
D=drill pipe OD, inches
K= ##EQU3## T s ="effective tension" in the drill string in 4 L=half the distance between tool joints, inches
The "effective tension", T s , or more precisely the bending-coupled tension, is calculated from the computer tally of drill string components by means of an equation taking the form of:
T.sub.s =T.sub.tb -ΣM.sub.a W.sub.a K.sub.b
in which
T tb =weight suspended by the traveling block, pounds
M a =tallied component lengths above the dog leg, feet
W a =weights in air of tallied components above the dog leg, pounds/foot ##EQU4##
The drill mud density may be manually keyed in the computer or an interface to the computer system may be employed with an automatic drill mud density sensor common to many drill rigs.
Fatigue data is usually developed in the laboratory by testing polished specimens subjected to fully reversed bending stresses with no axial tension. Such a fatigue curve typical of a Grade E drill pipe suggests the bending stress vs cycles to failure. (σ-N) curve in a non-corrosive environment shown in FIG. 8.
In the presence of an corrosive environment, this curve may be replaced by a curve located below the non-corrosive environment curve. For an extremely corrosive environment such as many drill muds, it is suggested a factor of 0.6 be applied to the ordinate of the σ-N curve. The o-N curve to be next illustrated demonstrates the application of a 0.6 corrosion factor to the non-corrosive environment curve. This corrosion factor may be varied according to field experience with various drill muds.
Drill string weight below the dog leg is suspended by the joints in the dog leg to result in axial tension in the components undergoing bending stress in the dog leg. In the presence of this axial tension, the fatigue effect of bending becomes much more severe. The effect of axial tension may be represented by the same σ-N curve previously illustrated but with bending stress 0 being replaced by an effective bending stress. τσ b , which accounts for axial tension. With this correction for tensile stress, the τσ b -N curve becomes that shown in FIG. 9.
The axial stress correction factor is obtained from the equation: ##EQU5## in which: t=ultimate tensile strength of the drill pipe, psi
O t =tensile stress, in psi, imposed on the drill pipe in the dog leg as calculated by: ##EQU6## in which: T tb =weight suspended by the traveling block, pounds
M a =tallied component lengths above the dog leg, feet
W a =weight in air of tallied components above the dog leg, pounds/foot
A=cross sectional area of a component in the dog leg, in 2
For steel pipe having a density of 489.5 pounds/cu. ft., the equation for σ t may be expressed as: ##EQU7## in which: W ac =weight in air of component in the dog leg, pounds/foot
The block suspended weight, T tb , is the total buoyed string weight with the bit off bottom minus the amount of weight run on the drill bit. The tension on the dog leg components regardless of weight run on the bit then is the traveling block suspended weight minus the summation of footage weights in air times their lengths of the components above the dog leg. There is no essentially no projected component area upon which incremental hydrostatic head differentials buoy the drill string components extending to the surface and the buoyancy factor need not enter this equation.
The estimate of the fraction of fatigue life expended by a drill pipe joint rotated at a certain number of cycles and stress as to incur fatigue damage is computed according to Miner's Rule by means of appropriate τσ b -N curves stored in the computer. This rule is illustrated in the above illustrated τσ b -N curve by an example whereby point "b" represents fatigue damage for the number of rotations counted by the rotary interface at computed stress level "b" while traversing a particular hole curvature. The fraction of fatigue life, f, expended by a component reaching this point of fatigue damage is: ##EQU8## in which: N b =number of cycles to point "b" at stress level "b"
N f =total number of cycles to failure at stress level "b"
According to Miner's Rule, these fractions of fatigue life expended are additive and the summations will provide a record of individual component cumulative fatigue damage recorded in a data element. Fatigue damage summations may be recalled from the data element as a percentage of fatigue life or as a fraction in which unity indicates imminent failure.
Bottom hole assembly drill collar fatigue estimates can also be mathematically computed through a procedure which requires additional input of information such as drilled hole sizes, whether and how drill collars are made concentric within the hole curvature with stabilizers, the amount of weight run on the bit with respect to buoyed bottom hole assembly weight and whether the dog leg angle is increasing or decreasing.
Referring now to FIG. 6, an additional embodiment of the invention is the ability to continuously monitor the exact location of tool joints, subs, valves or other shapes and diameters with respect to seal locations and elevations within sub-sea blowout preventer (BOP) stack 74. Sub-sea ram type BOP's are for the common purpose of closing around drill pipe in order to contain abnormal formation pressures. Ram type preventers 64 are outfitted with a pair of heavy steel rams containing a half circle with an elastomer type ram pack-off seal 58. When the ram pairs come together they completely encircle and seal around the drill pipe body. Due to the close tolerances necessary to encircle the pipe body and support the ram seal element under pressure, rams are unable to close properly around diameters different than what they were intended. Therefore is is essential that pipe ram closure around tool joints or off-size diameters be avoided and that the driller knows the position of tool joints or other unsealable objects within the BOP stack. Complete shut-off or blind rams 66 do not contain a pipe configuration and are designed to act as a valve if no pipe is in the hole. An annular type preventer 60 employs a large donut shaped elastomer seal element 62 forced into the well bore by an hydraulically activated cone arrangement. This type preventer is usually of a lesser pressure capability but is able to close around almost any shaped object. Annular preventer seal elements wear rapidly should a tool joint or off-size diameter repeatedly pass up and down through the element as caused by drill vessel heave in rough seas and therefor closure should also be maintained around the drill pipe body.
A distance measurement from the rig floor datum elevation is used to compare the location of tallied and tracked component and physical characteristics relative to pack-off or seal area elevations within the blowout preventer stack. Corrections to measurements from rig floor datum elevations to BOP seal areas are made for tides, vessel draft, vessel drift off hole center and vessel heave. These corrections are made by means of measuring distance variations from the drill floor elevation to the top marine riser section 68 just below the riser slip joint 70. As the top section of the marine riser represents a fixed length measurement to the sub-sea BOP stack, interface sensor 105 provides the measurement correction for tides, vessel draft, vessel movement off the well bore and sub-sea blowout preventer stack 74. This correction is made by means of a small diameter wire line connected to the top marine riser section which is spooled on an constant tension air hoist drum. As the vessel distance from the sub-sea stack varies, the constant tension air hoist drum either pays out or takes up the wire line. Line travel distance may be measured by sensor 105 using proximity switches in an similar manner to crown block fast line sensor 101. This correction is summed with block travel as compensated for vessel heave by piston travel of hydraulic cylinder type heave compensator 72 containing interface sensor 104. Interface sensors 104 and 105 are available from Oilfield Instruments, Inc., 17923 Fireside Drive, Spring, Texas, 77379.
A mathematical correction is also made by the computer for drill string stretch due to the drill string weight. In deep water this stretch is significant in the pipe section between the drill floor datum and the BOP stack elevation. This stretch or elongation computation is based upon pipe tension as determined by the weight suspended from the blocks, the distance to the sub-sea stack which has been established and entered in the computer and the automatic component tally with physical data, cross sectional areas, modulus of elasticity, Poissons Ratio and manually keyed drill fluid weight. Should the mud system have an automatic mud weight measurement device installed, sensor means can be substituted for manual drill fluid weight input. An equation for this elongation in general form is: ##EQU9## in which: Δz=total elongation
T tb =weight suspended by the traveling block
A=cross sectional area
L=distance between rig floor datum and sub-sea BOP stack
E=modulus of elasticity
δ s =density of steel
δ m =density of drill mud
ν=Poissons Ratio
In field units and with δ s =489.5 lbs/cu. ft., E=30,000,000 and ν=0.28, this equation may be expressed as: ##EQU10## in which: e=total elongation, inches
L=feet
T tb =pounds
W dp =drill pipe weight, lbs/ft
W g =drill mud weight, lbs/gal
Audible or visual alarms at preventer operating stations will provide warning against improper closure and a means of graphic display of the stack depicting component passage will be displayed to the driller.
While the above descriptions contain many specifics, they should not be construed as limitations on the scope of the invention, but rather as an exemplification of the preferred embodiments and applications thereof.
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A system for the automatic tallying of uniquely serialized drill string components from which well depth is determined, in hole component inventories are maintained, individual components are tracked through the well bore, component diameters are identified with respect to blowout preventer seal elevations and the determination and measurement of individual component down hole service factors with cumulative totalization in a computerized data base management system for these service factors for the purpose of better equalizing wear in order to obtain optimum life from drill strings.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of our application Ser. No. 915,761 filed June 15, 1978, now abandoned, entitled MULTIPLE ANALYSIS HEMATOLOGY REFERENCE CONTROL REAGENT AND METHOD OF MAKING THE SAME, this application being owned by the assignee hereof.
BACKGROUND OF THE INVENTION
This invention concerns a stable hematology reference control reagent suitable for use in common medical diagnostic procedures to analyze and test a patient's blood sample for making classic determinations with respect to the blood sample and more particularly, provides a novel diagnostic test control reagent which includes ingredients providing the control reagent with the capability of monitoring the desired platelet parameters of the patient's blood sample as well as the seven classic determinations or parameters with respect to the blood sample. In other words, the invention provides a single hematology reference control reagent which can be used for monitoring the precision and accuracy of the classic hematology measurements or determinations, i.e., red blood cell count (RBC), white blood cell count (WBC), hematocrit (HCT), the hemoglobin (HGB), the mean corpuscular hemoglobin (MCH), the mean corpuscular volume (MCV) and the mean corpuscular hemoglobin concentration (MHC) and as a control also for monitoring the accuracy and precision of the measurement and determination of platelet parameters such as platelet count, mean platelet volume, platelet volume fraction (thrombocytocrit) and platelet distribution width using the same whole blood product that is conventionally used for the control for the previously mentioned classical hematology parameters.
It is a common medical diagnostic procedure to analyze and test a blood sample of a patient in order to make certain classic determinations with respect to the blood sample. This procedure is an important diagnostic tool for the physician. As a result of modern technological advances, there have been automated instruments developed which will accept a patient's blood sample and process the sample automatically and continuously to provide the parameters or determinations described above as the seven classic parameters of a blood sample. An instrument which will accept a patient's blood sample and process same automaticlly and continuously to provide these seven classic parameters or determinations enumerated is described and claimed in U.S. Pat. No. 3,549,994. Said U.S. Pat. No. 3,549,994 provides acceptable definitions of such parameters and illuminates the problems to be solved in handling of the blood sample as it is drawn through the fluid system of said patented apparatus.
Coulter Electronics, Inc. of Hialeah, Fla., the assignee of this patent application, also manufactures and sells other blood cell counting and analyzing instruments which are less sophisticated than the apparatus of said U.S. Pat. No. 3,549,994 but which are operated to determine red blood cell and white blood cell counts, hemoglobin concentration and their collected indices such as HCT, MCV, MCH and MCHC.
In the use of such an instrument which may be referred to herein, at times, by the registered trademark "COULTER COUNTER" owned by Coulter Electronics, Inc., there is required to be employed a multi-purpose diluent comprising an electrolyte which enables electronic measurements to be made by the COULTER COUNTER® instrument. A suitable multi-purpose diluent for use in blood analysis by an electronic instrument such as the COULTER COUNTER® is described and claimed in U.S. Pat. No. 3,962,125.
A suitable reagent for determining leukocytes and hemoglobin in the blood sample by means of a high speed automated hematology instrument such as the COULTER COUNTER®is described in U.S. Pat. No. 3,874,852 issued Apr. 1, 1975. The reagent described and claimed in said patent is a lysing reagent for converting hemoglobin to a chromogen for making the desired determinations.
Coulter Electronics, Inc. has heretofore provided a hematology reference control for accuracy in electronic estimation of blood cell values capable of functioning with the diluent and lysing reagents discussed above. One such reference control has been sold by Coulter Electronics under its registered Trademark 4C which comprises a modified whole blood hematology reference control prepared from fresh human blood. Fixed erythrocytes were added to simulate leukocytes. This reference control had seven known blood values which were stable for a desired period of time. The reference control was prepared for use with the COULTER COUNTER® and accessory mean corpuscular volume hematacrit computers and hemoglobinominators. When used with the blood diluent identified above, it served as a check on accuracy of dilution, red blood cell counts, and MCV-Hematocrit computer calibration. After addition of a lysing reagent, the reference control served as a check on white blood cell counts. Thus, the so-called 4C® hematology reference control was utilized in the COULTER COUNTER® for electronic estimation of red and white blood cells, hematocrit, mean corpuscular volume, hemoglobin, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Other hematology reference controls also were available for use with the COULTER COUNTER® which comprise stabilized human red blood cell suspensions such as the product known as Baker Haem-C® of J. P. Baker Chemical Corporation or the product known as CH-60® of the Dade Reagent Company of Hialeah, Fla. However, none of these mentioned hematology control reagents were capable of being used for testing accuracy of measurements of platelet parameters. Consequently, for making such determinations, a separate control had to be employed for monitoring the platelet parameters. In other words, a separate control had to be employed for making the platelet determinations and the hematology control reagents for making the seven classical measurements or parameter determinations could not be employed for platelet control functions.
Further, prior art platelet counting has been inadequate because of the lack of stable platelet controls containing other blood components, namely, red blood cells. Thus, the increasing availability of instrumentation for distinguishing platelets from red blood cells and automatically performing platelet counts has created a great need for stable control products which contain both platelets and red blood cells.
The single hematology control of this invention includes the capability of monitoring platelet parameters as well as the seven classic parameters of hematology measurements. This hematology control has the advantage in that it eliminates the need for a separate control material for monitoring platelet parameters and provides a more meaningful determination of platelet parameters in that the potential interfering red blood cells, red blood cell metabolites, etc., normally observed in patient blood specimens are present in the control material of the invention. This is especially important for platelet counts performed with manual methodologies using light microscopy or phase microscopy, where great skills on the part of laboratory technologists is required to adequately differentiate blood platelets from red blood cells and other cellular materials. The subject invention also provides a means for monitoring these measurements using manual methodology or automated or semi-automated hematology instruments for hematology measurements along with a means for testing accuracy of platelet count, mean platelet volume, platelet volume fraction (thrombocytocrit) and platelet distribution based on the use in the reference control of the present invention of the same whole blood product which is conventionally used for control of the classic seven hematology parameters.
SUMMARY OF THE INVENTION
This invention consists of a stable whole blood control containing platelets prepared by adding freshly procured human blood platelets or animal blood platelets either natively drawn or preserved through chemical or physical fixation to a conventional, commercially available whole blood hematology control, such as said 4C®, Baker Haem-C® or Dade CH-60®. Such heretofore conventional, commercially available whole blood hematology control reagents are conditioned in accordance with the invention by adding sodium chloride and urea. The sodium chloride and urea may be added directly to the whole blood control or may be dissolved first in water and then added to the whole blood control. The components are present and/or are added in proportion such that the values for WBC, RBC, HGB, HCT, MCV, MCH, MCHC, red cell distribution width, platelet count, mean platelet volume, thrombocytocrit and platelet volume width distribution approximate those found in normally occurring human blood specimens and which can be measured by using a variety of known manual or automatic instrumentation methodologies. The suspension medium can comprise an artificial medium, human or animal plasma or animal protein solutions.
The 4C® product of Coulter Electronics, Inc. is a stable reference control which was especially suitable for use with the COULTER COUNTER® instrument when establishing standards of quality control for the performance of the instrument. A correctly calibrated and functioning instrument is utilized to provide the seven measured or calculated parameters within a range of expected results when the 4C® is used.
Also, the invention encompasses the disclosed method of making the stable reference control.
DETAILED DESCRIPTION OF THE INVENTION
This invention utilizes a combination of urea and sodium chloride as (1) a stabilizing agent for use with whole blood controls that include platelets and (2) an inhibitor of the detrimental effects of animal and human red blood cell metabolites, by-products, and chemicals inherent to the red blood cell and white blood cell on animal and human platelets.
Urea alone previously has been employed as a stabilizing agent in pure suspensions of human blood platelets prepared as a control material to be used in connection with performing platelet counts. The human blood platelets prepared in this manner have been essentially in pure suspensions; no residual red blood cells or white blood cells have been allowed to be present in such controls. The function of the added urea in such control suspensions simply has been to prevent the gradual disintegration of the platelets during subsequent storage over a period of time equaling several months. The overall effect has been to provide a suspension of platelets that remains relatively constant (±20%) in the number of blood platelets per unit volume. If the urea were not added, the number of particles per unit volume would gradually increase as the platelets began to disintegrate usually within several days.
Heretofore, red blood cells and white blood cells have not been allowed to be present in platelet controls. The reason is believed to be that these cells almost immediately cause platelets to aggregate and disintegrate, thereby destroying the effectiveness of the mixed control material. In addition, urea in high concentrations was known to be detrimental to the stability and integrity of red blood cells, thereby apparently precluding its use as a preservative in suspensions containing red blood cells. As a result, prior known platelet controls have consisted simply of pure suspensions of human platelets in the presence of urea as a preservative, no red blood cells or other formed elements of the blood having been allowed to be present, thereby diminishing their effectiveness as control materials.
Until the present invention, there have been no known successful combinations of whole blood reference controls that contain preserved human platelets stabilized with two molar urea. In fact, present art teaches that when two molar urea employed in this invention is added to human blood cells, the red blood cells are destroyed (Owen, J. D., "Computer Simulated Urea Reflection Coefficients In Human Red Blood Cells," Biochem. et Biophys. Acta 443, 306-310, 1976; Saunders, A. M., Scott, F., "Hematologic Automation By Use Of Continuous Flow Systems," J. Histochem. Cytochem. 22, 707-710, 1974).
We have discovered that urea in the presence of sodium chloride serves to prevent the deleterious effect of autologous red blood cells and white blood cells on blood platelets in the suspension. Consequently, we provide a stable blood platelet suspension that contains red blood cells and approximates the composition of human blood. There is provided a single stable suspension which contains both blood platelets and red blood cells, made possible through the use of a combination of urea and sodium chloride which is added to previously stabilized human red blood cell suspensions, such as Coulter 4C®, Baker Haem-C®, or Dade CH-60®, which can easily tolerate the otherwise detrimental effects of urea. The combination of urea, saline and the previously preserved red blood cell suspension is itself uniquely stable and provides a compatible medium in which either native blood platelets or blood platelets that have been fixed using formaldehyde, glutaraldehyde, osmic acid or other chemical fixative agents can coexist in stable form.
Another derived benefit of this invention is that the combination of urea, saline and previously fixed red blood cell suspensions provides an environment in which the cell volume of individual blood platelets remain unchanged. By use of a combination blood platelet and red blood cell control suspension, it is now possible for laboratories to monitor the accuracy of platelet count, mean platelet volume (MPV) and platelet volume distribution (PDW) measurements, so that effective patient measurements may be performed on a routine basis.
A whole blood control containing platelets according to the invention was prepared by mixing conventional, commercially available whole blood control products such as Coulter 4C®, Baker Haem-C® or Dade CH-60® with freshly collected or chemically preserved human blood platelets or animal blood platelets and a mixture of urea and sodium chloride. After stabilizing for several days, the suspension was found to have stable values for the hematology parameters WBC, RBC, HGB, MCV, HCT, MCH, MCHC, red cell distribution width, platelet count, mean platelet volume, thrombocytocrit and platelet volume distribution width. The detrimental effects of the red blood cells and white cell analogs present in the whole blood controls used as substrate was prevented by the addition of sodium chloride and urea and the material could be used as a stable control for several months.
METHOD OF PREPARING CONTROL REAGENT
The first step, in one mode of preparing a whole blood platelet control of this invention was to procure a volume of conventionally manufactured whole blood hematology reference control material such as Coulter 4C®, Baker Haem-C® or Dade CH-60®, or any other commercially manufactured or other suitable whole blood hematology control material comprising treated erythrocytes in an artificial medium. Then human or animal blood platelets were procured through venipuncture or other bleeding procedure of the donor human or animal subject. The human or animal blood platelets can then be used in any manner whatsoever either as freshly obtained or after any of the chemical or physical fixative procedures have been applied to the platelets.
The next step was to prepare a solution or urea and sodium chloride in water or other vehicle for subsequent mixing with the whole blood control and the platelets. In the solution, the urea and sodium chloride are added in the following relationship, generally, to 1000 ml of medium, e.g., water,
Urea--120 gms
Sodium Chloride--9 gms
Variations in urea used in one liter of medium range between 100 and 140 gms and sodium chloride between 8 and 10 gms. The urea and sodium chloride were either mixed with each other and subsequently added to the control suspension or were dissolved in approximately one liter of medium, e.g., water, (for example,) and the resulting solution added at that time to the control material in amounts to be discussed hereinafter. A salt equivalent to sodium chloride may be utilized.
The final step was to simply mix the commercially or individually prepared whole blood hematology reference control, the untreated, unstabilized or previously stabilized platelet suspension and the solution of urea and sodium chloride together. After mixing for approximately 30 minutes, and allowing the cell suspension to stabilize for approximately 48 hours, the control material was stable for complete hematoloty parameters, as stated. A selective suspension of red blood cells and platelets is realized. The suspension medium can be artificial, or a human or animal plasma or human or animal protein solutions.
The following examples show how suspensions of treated red blood cells, platelets and solutions of sodium chloride and urea can be mixed together to provide the whole blood control of the present invention, as described:
(1) A solution containing 24 grams of urea and 1.8 grams of sodium chloride in 200 ml of distilled water is added to 1000 ml of a treated whole blood suspension such as Coulter 4C®.
A solution containing 2.4 grams of urea and 0.18 grams of sodium chloride in 20 ml of distilled water is added to 100 ml of a human platelet suspension.
Each resulting suspension is mixed for several minutes and then treated red blood cell suspension and platelet suspension, both containing urea, are mixed with each other thoroughly for approximately thirty minutes and allowed to subsequently stabilize for approximately 48 hours to provide the reference control of this invention.
(2) 20.0 grams of urea and 1.5 grams of sodium chloride are directly added to 1000 ml of a treated whole blood suspension such as Coulter 4C®. 100 ml of a human platelet suspension is then directly added to the treated whole blood control suspension containing urea and sodium chloride. The suspension is mixed for approximately 30 minutes and allowed to stabilize for 48 hours to provide the reference control of this invention. It will be noted from this embodiment that it is not required to solublize the urea and sodium chloride prior to admixture with the treated whole blood suspension.
(3) A solution containing 26.6 grams of urea and 1.98 grams of sodium chloride in 220 ml of distilled water is directly added to 1000 ml of a treated whole blood control suspension such as Coulter 4C®. 100 ml of a human platelet suspension is then added. The resulting suspension is mixed for approximately 30 minutes and allowed to stabilize for 48 hours to provide the reference control of this invention.
In the reference control of the present invention, urea is present in the relationship of between about 16.7 to about 23.3 grams in approximately one liter of the reference control of the invention.
Also, in the reference control of the invention, sodium chloride is added, in relation to the urea concentration, i.e., 1.33 to 1.67 grams sodium chloride to each liter of reference control containing the aforementioned 16.7 to 23.3 grams of urea.
It is to be understood that this added amount of sodium chloride is additional to the residual salinity of the treated whole blood suspension or platelet suspension to which same is added. It will further be understood that the significant factor in accordance with the invention, is the relationship between the urea and the added sodium chloride, not the total salinity of the reference control.
It is this relationship between the urea and the added sodium chloride that enables the preparation of a stable reference control containing at least both red blood cells and platelets.
The following will be noted with respect to the effect and importance of added sodium chloride. Most starting materials used in the present suspension, stabilized blood controls and platelet suspensions contain previously added sodium chloride. The invention describes adding a mixture of urea and sodium chloride to these materials so that they may co-exist. The purpose of the added sodium chloride is to maintain the osmotic and ionic balance when urea is added.
One should consider that there exists an independence of cell count (platelets, red blood cells and white blood cells) and cell characteristics (mean cell volume, and cell morphology) from chemical composition of the reference control of the invention. The chemical composition of the reference control of the invention consisting of previously stabilized red blood cells and fixed red blood cells, platelets, and added urea and added sodium chloride, is independent of the desired cell count and cell characteristics. For example, the invention allows approximately 100 ml of a suspension containing either very many platelets or very few platelets to be added to approximately 1000 ml of an existing whole blood control such as Coulter 4C® having a high or low red blood count in white blood count value, in the high or low mean cell line value so that the resulting approximate volume of 1100 ml of cell suspension has relatively few or many platelets, red blood cells and white blood cells, depending upon the levels desired.
As used in the art and in this specification, the terms "stabilized" and "treated" as applied to blood cells, are synonymous and are contrasted with the term "fixed cells." Both the initial starting materials described in this invention (the previously stabilized cell control and the platelets) can consist of either stabilized or treated cells, chemically fixed cells or native untreated cells.
For example, Coulter 4C® consists of stabilized (treated) red blood cells and chemically fixed red blood cells.
Stabilized (treated) cells consist of human or non-human cells to which various preservatives have been added to prolong their life.
Chemically fixed cells consist of human or non-human cells which have been chemically hardened, i.e., tanned, usually by chemicals such as glutaraldehyde, formaldehyde, osmic acid or uranyl acetate.
Stabilized cells are generally susceptible to hemolysis or disruption in the presence of surfactants or low osmolality, while chemically fixed cells retain their morphology under such environments.
As explained, the hematology reference control embodying the invention was suitable for use in making manual determinations as well. Persons skilled in the art know the methodologies used for manual determinations of RBC, WBC, HGB and HCT using such control reagents. It is believed unnecessary to explain in detail these manual methodologies, it being sufficient to appreciate that the reference control of the invention can be used both for instrumentation and manual methodologies, as described herein.
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A single diagnostic test reagent for use as a multiple-analysis hematology reference control for monitoring the precision and accuracy of measurements or determinations of red blood cell, white blood cell and platelet blood cell counting, hemoglobin content, hematocrit, mean cell volume and mean platelet volume determination, red cell distribution width and platelet distribution width determination, and determination of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and thrombocytocrit. The control reagent includes ingredients for monitoring platelet parameters also notwithstanding that potential interfering effects of red blood cells normally observed in blood specimens also are present in the control reagent. The control reagent is suitable for use in automated or semi-automated hematology instruments and by users of manual methodologies.
The invention includes a method of making said control reagent.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to a jack stand apparatus and more particularly to a jack stand with a spring triggered safety engagement.
2. Description of the Prior Art
The demand for inexpensive jack stands has arisen over the years due to a consumer need to perform a wide range of automobile maintenance and repair functions at home. Jacking type devices have proven to have certain safety drawbacks when used to maintain the automobile in a vertically suspended position. By utilizing inexpensive jack stands, a single more expensive jacking device may be used to meet all of the consumer's jacking needs. In its basic application, the jack stand provides a wide base and a sturdy support structure for maintaining a vehicle suspended in a raised position to enable maintenance and repair type functions to be performed on the vehicle. A variety of jack stands have been utilized to meet the diverse and changing needs of a society dependent on the automobile.
Jack stands, in general, have developed from a basic design which is made up of a sturdy wide base structure and a telescoping vertical support member or stem. The vertical support member can be adjusted to increase or decrease the overall height at which the jack stand will support a vehicle. Once a particular height has been selected, movement of the vertical member relative to the base is locked, in some manner, thereby providing a secure sturdy means of supporting the vehicle.
Devices of this type can fall generally into two categories. A first design category requires the insertion of an engaging pin to secure the vertical member at selected positions for various different heights relative to the base structure. While the pin type device provides a sturdy work structure, the limited number of holes allowed by the limits on structural integrity can substantially increase the distance between the jack stand and the height of an elevated vehicle. Designs of this type are shown in U.S. Pat. Nos. 1,416,896 by Simmons, 2,439,854 by Lipski, and 4,042,202 by Molinari. While satisfactory for some applications, in other applications jack stands of this type suffer shortcomings in positioning caused by large gaps between the jack stand and the elevated vehicle. These positioning errors may cause the jack stand to slide out of position or to support the automobile in an undesirable manner resulting in damage to other automobile components having insufficient structural integrity to support the weight of the vehicle. In order to avoid this problem the user may need to adjust the height of the stand while under the vehicle. This condition may expose the user to the dangers associated with a vehicle supported by a jacking device of the type which may not possess the structural integrity of a jack stand.
A second design category incorporates a set of interlocking teeth disposed on a vertical edge of the vertical support member. A pawl positioned on the base support structure by a pivot pin engages with the teeth providing a variety of support positions for the jack stand device. Typically such teeth are of a general saw tooth shape for free and rapid ratcheting upwardly of the stand relative to the pawl. A jack stand of this type is more convenient to position at a height closely nesting under the axle of the vehicle to be supported by a jacking device. By reducing the distance the vehicle will travel when the jacking device is released, the problems that may arise from a sudden change in the vertical position of the vehicle has been reduced.
The pawl is usually mounted on the base support structure by a pivot pin. When the vehicle is to be removed from the jack stand, the jacking device resumes the load of the vehicle and a handle located on the pivot pin may be grasped to release the pawl from engagement with the teeth of the vertical support member to free it for lowering. The handle provides a quick release allowing the vertical member to telescopically decline to its lowest position for quick retrieval from the underside of the vehicle. A device of this type is shown in U.S. Pat. No. 1,320,613 by Gilcrease.
While these ratchet type devices provide an advantage over the pin type jack stands, there still remains some disadvantages. The pawl engagement with the vertical support stem sustains the position of the vertical support member only against retraction into the base. This typically leaves the support stem free to be drawn or to fall free of the base and become disassociated therefrom.
This can create an unsafe situation for the automobile mechanics or do-it-yourselfer employing the stand. The general tendency is for the workman to, when transporting the stand from place to place, grasp it by either the stem or the base to carry it in an inverted orientation.
This can create a serious problem in that the vertical support stem is free to slide past the pawl free of the base to impact the workman's foot or toe. This condition can also result in a substantial hazard to the work area caused by the heavy vertical support member falling out of the base support and damaging other delicate tools or automobile components. Further, the unwanted disassociation of the vertical support from the base is an inconvenient and irritating problem for the workman seeking to repeatedly transport the stand from one location to another.
While some ratchet type designs provide a stop to restrict the vertical support member from coming completely free from the base structure, the vertical member may still slide freely out to a fully extended position. By creating such a sudden change in its center of gravity or impact upon engagement with the stop, the sudden load change may still cause the person carrying the device to drop the jack stand or allow the free falling stem to strike the workman or nearby object causing injury or damage.
Some ratchet type designs recommend a spring loaded pin to engage the vertical support member at its lowest vertical position within the base. This type of safety device locks the position of the vertical member within the base structure. The major drawback of this safety feature is that to be effective, the user must manually engage by pin each time the device is used. This manual engagement, which should be initiated during cleanup, may often be overlooked in the press of time often surrounding the completion of a major automotive repair project.
In instances where it is necessary to employ two to four jack stands for a particular task, the setting of a fixed equal height on all the jacks may be critical in providing a safe working environment. The procedure of moving the vertical support stem to the safety position may result in losing the specific height necessary for work on a continuing project. While the safety pin design provides a manually engaged safety device and a quick release to lower the device's height, there remains a safety hazard for those instances that would require that the jack stand be maintained in a pre-positioned height for continued work on a particular project.
Other ratchet type jack stands provide for a pin to be biased into normal engagement with the teeth of the vertical support member. Disengagement of the pin can then only be accomplished by manually holding the pin in its disengaged position. This task can be difficult from certain positions under the car, especially if the mechanics hands are greasy, thus creating a safety hazard which hampers the effectiveness of the ratchet device to quickly adjust to various heights.
Consequently, there exists a need for a jack stand which can be quickly adjusted to permit convenient positioning and retrieval while securing the vertical support member from movement automatically when the device is being transported in an inverted position.
SUMMARY OF THE INVENTION
The current invention encompasses an improved jack stand including an adjustable height stem formed on one side with a rack of teeth. Such stem is adjustably locked at a selected height by a pawl biased into engagement by a torque spring between selected pairs of the teeth. The teeth and pawl are so configured and arranged as to cause the pawl to be normally engaged between a selected pair of teeth, in the supporting mode, to afford support against the upper tooth to maintain the stem elevated relative to the base. In the inverted position of the stand, the pawl is biased into engagement with the lower tooth of the pair to trap such stem from freely telescoping relative to such base.
The current invention further encompasses a convenient handle to operate a release mechanism to disassociate the pawl secured by torque spring engagement thus permitting the jack stand to quickly retain a diminutive height.
The combination of an improved ratchet tooth design, a dual traction pawl, and torque spring provides a sturdy jack stand with quick release and restraint against accidental separation of the stem from the base.
Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the improved jack stand of the present invention;
FIG. 2 is a broken side view, in enlarged scale, of the improved jack stand of FIG. 1 showing the ratchet engagement mechanism;
FIG. 3 is a vertical sectional view, taken along the line 3--3 of FIG. 2; and
FIG. 4 is a horizontal sectional view taken along the line 4--4 of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The jack stand apparatus of the present invention includes, generally, a pyramidal shaped base 11 having telescoped therein a stem 13 formed at its top end with a cradle 15 and along one side therewith a tooth rack 17. Referring to FIG. 3, mounted on the base 11 is a generally tear drop shaped pawl, generally designated 21, which is configured for engagement between pairs of teeth 51 in the rack 17. The pawl 21 is biased into positive engagement with such tooth rack 17 by means of a torque spring, generally designated 23, to thus cause such pawl to provide a support against weight placed on the stem 13, as well as to positively lock such stem against telescoping out of, and disengagement from, such base 11.
It has been common practice for automobile mechanics and do-it-yourselfers alike to utilize jack stands, for instance, to maintain an axle of an automobile elevated for convenient access to the underside of the vehicle for achieving repair work. Typically, such jack stands have incorporated an arrangement for maintaining different elevations of the supported vehicle. Some such jack stands have incorporated a rack tooth arrangement on an elevatable stem engageable by a pawl for the purpose of maintaining the elevatable stem at different selected adjusted heights. However, heretofore there has been no jack stands that incorporate a tooth and pawl arrangement which provides, not only for elevation of the stem to different heights, but also provides for locking the stem in its adjusted position against unwanted telescoping upwardly relative to the base 11 and consequent disengagement from such base.
It has been known to construct a base 11 of the general configuration shown for receiving and supporting a stem 13 of the same general configuration shown in the drawings. The base 11 is conveniently constructed of formed sheet metal conveniently formed at its bottom with four spaced apart feet 27 and in opposed walls with respective triangular apertures 29 to define in the lower portion of the base a rail 31. The base weighs about nine pounds so in a free fall can impart damage or injury upon impact. The base 11 is formed in its upper portion with a generally rectangular in cross section tubular neck 35 formed on the side with a window 41 confronting the tooth rack 17 (FIG. 3). The opposed walls of the neck 35 project laterally outwardly beyond the plane of the window 41 to form laterally spaced apart flanges 45 and 47 configured to receive therebetween the pawl 21. The pawl 21 is conveniently carried from such flanges 45 by means of a pivot pin 50. Such pivot pin has a lever arm projecting from one end thereof to define a handle 52. The pawl itself is generally tear drop shaped to curve upwardly and inwardly as shown in FIG. 3 for engagement between respective pairs of teeth 51 formed in the tooth rack 17.
The teeth 51 of the tooth rack 17 are of a conventional modified square configuration to be formed on their bottom and top sides with perpendicular surfaces to form the bottom surface and free end surfaces disposed in planes perpendicular to one another. The corner 54 formed between the bottom and top ends of such teeth defines a latch surface disposed for engagement with the underside of such pawl 21 to thereby limit upward travel of the stem relative to the base 11. The top surfaces 53 of the teeth 51 then angle upwardly and inwardly as viewed in FIG. 3 at an angle of approximately 30° to the horizontal.
The pawl 21 is configured such that its top end angles upwardly and inwardly, terminating in a somewhat pointed tip end 61 which is configured to engage beneath the bottom surface of the respective teeth 51 to support the stem 13 against the weight of the vehicle carried on the cradle 15. The interior surface of the pawl confronting the teeth 51 curves upwardly and inwardly, when engaged as shown in FIG. 3, to be disposed in the path of the upper outer latch corner 54 of the tooth 51 disposed therebelow. Thus, such upper outer corner 54 of the tooth will, upon upward travel of the stem 13 relative to such pawl, engage such pawl along the latch stop line designated 63 (FIG. 3) thereby causing the pawl to act as a latch preventing unwanted upward travel of the stem 13 relative to the base 11.
If desirable, the teeth 51 may be square without slope to the upper side 54. However, for the 30+ incline shown in FIG. 3, it is possible, under the right condition, to ratchet the stem to its extended position. That is, the operator may place his feet on the opposite rail 31 and draw upwardly on the stem 13 with a force in excess of 15 pounds to cause the upwardly acting force to overcome the torque applied by the spring 23 to deflect the pawl 21 out of the path of the teeth 51. The stem may thus be ratcheted rapidly upwardly to position the cradle 15 at the approximate desired height.
However, for normal operation of the configuration shown, it has been discovered that by constructing the spring 23 with a sufficient torque, the configuration of the tooth and pawl arrangement will normally latch such stem against unwanted extension. That is, the spring 23 is selected to cooperate with the handle 52 to provide a sufficient clockwise torque on the pawl 21 as viewed in FIG. 3 to maintain such pawl in its engaged position between the adjacent teeth with sufficient force to resist telescopical disengagement of the stem 13 from the base 11 upon the stand itself being inverted and the full weight of the stem 13 and yoke 15 being applied to the pawl.
In this regard, for a conventional five ton rated jack, a forged stem and yoke typically having a weight of about 51/4 pounds, the spring may be situated to apply torque sufficient to cause the pawl 21 to resist extension of such stem under its own weight. For this configuration, it has been found that with an angle for the upper surface of the tooth of about 30° the torque provided is sufficient to latch the 51/4 pound stem and yoke against unintentional telescoping from the neck 35 with the jack stand inverted. This has been found particularly useful in preventing unwanted disassociation of the stem from the base which might result in injury to the workman or inconvenience from separation of the stand parts. The slope of this top surface may, in fact, be increased but must be maintained less than 45° to the horizontal.
It has also been found that for a conventional base 11 for a jack stand of a five ton rating, the spring 23 will apply sufficient torque to the pawl 21 to maintain it engaged with sufficient force to maintain the stem latched against telescoping upwardly thereof when the workman grasps the cradle 15 to bodily lift the jack stand and carry it from place to place.
In operation, it will be appreciated that the jack stand may be positioned under an elevated automobile axle and the handle 52 grasped with one hand to rotate the pawl counterclockwise as viewed in FIG. 3 to move the tip 61 and latch surface 63 out of the path of the teeth 51 to free the stem 13 for elevation thereof to the desired height for the cradle 15. Release of the handle 52 will then free the pawl 21 to be biased into its locking and latching position shown in FIG. 3 to thus lock the stem 13 against lowering thereof. The jack (not shown) may then be lowered to lower the weight of the axle onto the cradle 15.
When the repair job is completed and it is desirable to lower the vehicle axis, the jack may again be operated to raise the axle and free the cradle 15. The handle 52 may then be rotated counterclockwise to rotate the pawl 21 clear of the teeth 51 to thereby free the stem 13 for lowering relative to the base. The jack stand will then be available for moving to another location for either storage or use in another automobile repair job.
Such movement to another location may be conveniently achieved by, for instance, grasping the cradle 15 and carrying such jack stand to the desired location. It will be appreciated that under such conditions, the pawl 21 will be urged to its clockwise position shown in FIG. 3 with sufficient force to maintain engagement of the latch surface 63 with the upper outer edge of the tooth 51 disposed therebelow. This then serves to positively maintain the stem 13 and base 11 in engagement with one another to thereby prevent unwanted disassociation thereof and possible dropping of the base onto the worker's toe, foot or leg.
In some instances, it is common practice for the workman to, in transporting the jack stand about, grasp the rail 31 and transport such jack stand from place to place. In this instance, the jack stand even though inverted will serve to maintain the stem in its securely latched position.
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A jack stand apparatus comprising a broad stable base to ensure safe support of a raised object with a selectively positioned vertical support member secured by a ratchet and pawl type engagement mechanism. The jack stand in its free state maintains the pawl in engagement with the ratchet by means of a torque spring which applies sufficient force to ensure engagement of the pawl with the ratchet in any position. This spring biased type pawl ensures engagement of the pawl and ratchet to prevent sudden movement of the vertical support member during transport. A pivot pin handle which carries said pawl and torque spring may be manually rotated with sufficient force to oppose the torque spring thus permitting disengagement of the pawl from the ratchet.
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FIELD
[0001] There is described a method of removing carbon dioxide during production of Liquid Natural Gas (LNG) from natural gas at gas pressure letdown stations.
BACKGROUND
[0002] In Canadian Patent 2,536,075 entitled “Method of conditioning natural gas in preparation for storage”, there is disclosed a method in which natural gas is divided into a primary stream and a secondary stream. Through a series of heat exchanges a temperature of the primary stream is raised in preparation for consumption and a temperature of the secondary stream is lowered in to produce Liquid Natural Gas (LNG).
[0003] A serious problem not addressed in this patent is the presence of carbon dioxide (CO 2 ) in the LNG . In the production of LNG , cryogenic temperatures are reached where the carbon dioxide can form dry ice which can plug lines and equipment. When producing LNG at gas pressure letdown stations the carbon dioxide must be removed to prevent the formation of dry ice and plugging of lines and equipment on the production plant. Traditionally, this concern is addressed by employing mol sieves to absorb and remove the carbon dioxide from the LNG production gas stream. These mol sieves are the largest component of a LNG plant and are energy intensive to regenerate. There will hereinafter be described an alternative method of addressing carbon dioxide removal.
SUMMARY
[0004] There is provided a method of removing carbon dioxide during Liquid Natural Gas production from natural gas at a gas pressure let down station. The method involves passing high pressure natural gas through a first heat exchanger to pre-cool the high pressure natural gas entering the pressure let down station. The pre-cooled high pressure natural gas is then passed through a separator to remove condensates from the high pressure natural gas exiting the first heat exchanger. The high pressure natural gas is then passed through a natural gas dewatering unit to remove water from the high pressure natural gas exiting the separator. The dewatered high pressure natural gas then is passed through a second heat exchanger to pre-cool the dewatered high pressure natural gas. A step is then taken of splitting the dewatered high pressure natural gas into a Liquid Natural Gas production stream and a gas for consumption stream. The Liquid Natural Gas production steam is passed through a third heat exchanger to pre-cool the Liquid Natural Gas production stream. The Liquid Natural Gas production stream is passed through a carbon dioxide stripping column to remove carbon dioxide. The gas for consumption stream is passed through a first pressure reduction unit to depressurize the gas for consumption stream. The gas for consumption stream is passed through a second separator to recover condensed hydrocarbon fractions from the gas for consumption stream. The condensed hydrocarbon fractions from the gas for consumption stream are routed to the stripping column for use as a carbon dioxide stripping adsorption agent. The Liquid Natural Gas production stream is then passed through one or more further heat exchangers to further cool the Liquid Natural Gas production stream to facilitate Liquid Natural Gas production. The Liquid Natural Gas production stream is passed through a second pressure reduction unit to depressurize the Liquid Natural Gas production stream. A final step is then taken of passing the Liquid Natural Gas production stream through a third separator to achieve separation of Liquid Natural Gas from vapours.
[0005] The above described method achieves the objective of removal of carbon dioxide from the Liquid Natural Gas production stream by using hydrocarbon fractions taken from the gas for consumption stream as a carbon dioxide stripping adsorption agent for the stripping column used to remove carbon dioxide. There is much less cost and maintenance associated with this method, as compared to the use of a mole sieve.
[0006] The pressure reduction units used can be gas expanders or J.T. (Joules-Thomson) valves. The use of gas expanders will be described and illustrated with reference to FIG. 2 and the use of a J.T. valve will be described and illustrated with reference to FIG. 3 . The use of gas expanders is preferred as they are more efficient and produce colder temperatures. IN addition, when a gas expander is used with an associated generator, energy is produced that can be used for other purposes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:
[0008] FIG. 1 (labelled as “PRIOR ART”) is a schematic diagram of a pressure letdown station equipped with JT valves for pressure controlled letdown, a heater and a heat exchanger.
[0009] FIG. 2 is a schematic diagram of a LNG production process at added to an existing gas pressure letdown station and equipped with; gas pre-treatment units, heat exchangers, a stripping column, gas expanders, KO drums, pumps and LNG storage. The process natural gas stream is supplied from high pressure natural gas transmission pipeline.
[0010] FIG. 3 is a schematic diagram of a LNG production process involving the use of J.T. valves in place of gas expanders, but in all other respects identical to FIG. 2 .
DETAILED DESCRIPTION
[0011] The method will now be described with reference to FIG. 1 through FIG. 3 .
[0012] Referring to FIG. 2 , this method was developed with a view to pre-treat and produce LNG at gas pressure letdown stations. The disclosed invention utilized a different approach in a unique and innovative variant of the methane expansion cycle, which to date is used in commercial applications known as letdown plants. The system here described takes advantage of the gas streams delivered to end users at pressure letdown stations. The inventors, have previously been granted a patent for LNG production at pressure letdown stations employing expanders/generators, heat exchangers and separators to generate and recover refrigeration to produce LNG. This invention allows for an improved method of producing LNG at gas pressure letdown stations. This method allows for LNG to be pre-treated for the removal of carbon dioxide using the condensed heavy hydrocarbon fractions as a stripping agent in a stripping column. This is an improvement on the existing practice of mol sieves for carbon dioxide removal. The stripping agents employed in the stripping column are the hydrocarbon fractions condensed and recovered in a separator downstream of the expander/generator on the continuous natural gas stream. These hydrocarbon fractions are ideal stripping agents in terms of temperature and composition for carbon dioxide stripping in a stripping column. This new feature is an improvement on the writer previous patented LNG production process at gas pressure letdown stations. The description of application of the method should, therefore, be considered as an example.
[0013] Referring to FIG. 1 , a typical gas pressure letdown station in a natural gas transmission pipeline. Natural gas is delivered from an high pressure transmission pipeline, gas stream 1 is first pre-heated in heat exchanger 2 , the heated gas stream 3 is depressurized through a JT valve 4 to pipeline 5 pressure setting 7 and then routed to end users. A gas stream 8 provides the fuel required to heater 9 . A closed recycling loop glycol/water 10 transfers the heat from heater 9 to gas heat exchanger 2 to pre-heat the gas. A temperature setting 6 controls the gas pre-heat requirements. This simplified process arrangement as shown is FIG. 1 constitutes a standard operation at gas pressure letdown stations. The purpose of pre-heating the gas before decreasing the pressure at the pressure letdown station is to prevent the formation of hydrates due to the presence of water in the gas composition.
[0014] Referring to FIG. 2 , the proposed invention process arrangement is added to an existing pressure letdown station as shown operating in parallel. In the proposed invention, stream 13 is first pre-cooled in heat exchanger 14 , the cooled stream 15 enters separator 16 where condensate is removed through stream 17 . The vapour stream 18 is de-watered in pre-treatment unit 19 . The dried gas stream 20 is further cooled in heat exchanger 21 . The cooler gas stream 22 is split into streams 23 and 24 . Stream 23 is the continuous natural gas stream to end users, it is reduced in pressure at expander/generator 25 / 26 to meet the pressure requirements of end users. The dry, depressurized, very cold, gas stream 27 enters separator 28 where the condensed hydrocarbon fraction is separated from the vapour fraction. Stream 24 is further cooled in heat exchanger 31 before entering CO2 stripper column 41 . The separated very cold gas stream 29 is split into streams 30 and 35 . Stream 30 is warmed up in heat exchanger 31 , 21 and 14 before distribution to end users. Stream 35 is warmed up through heat exchangers 46 and 14 before distribution to end users. The very cold condensate stream 38 enters pump 39 and is pumped to stripper column 41 as an adsorption stream 42 to strip CO2 from stream 24 . A mixture of CO2 and heavy hydrocarbon fractions exit the stripping column 41 through stream 43 and pump 44 . The CO2 stripped gas stream 45 is further cooled in heat exchangers 46 and 48 before entering expander/generator 50 / 51 and entering separator 53 through line 52 . The liquid fraction LNG exits separator 53 to storage through line 54 . The cryogenic vapour 55 is warmed up in heat exchanger 48 , enters compressor 56 , is routed through line 57 and mixed with stream 58 and delivered to end users through line 59 .
[0015] The inventive step in this process is the generation and recovery of coolth energy in conjunction with a diverted gas stream 24 to pre-treat and produce LNG using a CO2 stripper column at gas pressure letdown stations. The use of expanders/generators in pressure reduction processes to generate the Joule Thompson effect is well understood and in practice in the gas industry in various forms. The advantage of the proposed invention is the process configuration which utilizes produced condensed hydrocarbon fractions as a stripping agent in a stripping column at a pressure letdown station to strip the CO2 fraction from the LNG production stream. Typically pressure letdown stations operate as shown in FIG. 1 , requiring the use of a portion of the gas flow through the station (generally about 1% of the gas flow) to pre-heat the gas to prevent the formation of hydrates. The proposed invention eliminates the present practice of combusting gas for gas pre-heating. It eliminates the need to use the industry standard mol sieve technology at a pressure letdown station to remove CO2 from a natural gas LNG producing stream. The CO2 stripping adsorption agents are the hydrocarbon fractions condensed in the process from the natural gas stream to end users. The amount of adsorption agent required can be met through a controlled recycled stream supplied from stream 44 until it reaches steady state since there is a continuous new supply of hydrocarbon fractions from stream 38 .
[0016] FIG. 3 shows the same method as that illustrated in FIG. 2 , with all reference numerals indicating identical elements. The only difference between FIG. 2 and FIG. 3 , is that in FIG. 2 the pressure reduction units used are gas expanders 25 and 50 , whereas in FIG. 3 the pressure reducing units are gas expander 25 and J.T. Valve 60 are used as pressure reduction units in place of gas expander 50 .
[0017] In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.
[0018] The scope of the claims should not be limited by the illustrated embodiments set forth as examples, but should be given the broadest interpretation consistent with a purposive construction of the claims in view of the description as a whole.
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A method is described for removing carbon dioxide during Liquid Natural Gas production from natural gas at gas pressure letdown stations. The above method removes carbon dioxide from a Liquid Natural Gas production stream by using hydrocarbon fractions taken from a gas for consumption stream as a carbon dioxide stripping adsorption agent for a stripping column used to remove carbon dioxide.
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BACKGROUND OF THE INVENTION
The present invention relates generally to animal feeding devices. More specifically, the present invention relates to bird feeders.
It is desirable that bird feeders stay clean and dry. Because bird feed is relatively costly, feeders must not dispense feed in such quantity that it spills onto the ground, but a feeder must dispense sufficient feed so that birds are not left hungry. A bird feeder should also be adjustable to accommodate different types and sizes of bird feed, as well as different sizes and weights of feeding birds.
The feed containers of prior art feeders are generally an integral part of the bird feeder, and thus the containers eventually become dirty, damp, and musty. Further, because the flow rate of prior art feeders is not adjustable, they dispense too much or too little feed, and tend not to be suitable for more than one type of feed. Finally, prior art feeders dispense feed at a constant rate, regardless of the number and weight of birds using the feeder.
SUMMARY OF THE INVENTION
The present invention eliminates the problem of too little or too much feed being dispensed because feed is dispensed as a function of the weight and motion of feeding birds. Movement of the birds stimulates the flow of feed and prevents clogging. The present bird feeder invention is adjustable to accommodate the type of feed being used and the weight and number of birds using the feeder. A removable container is used, thereby eliminating the problem of damp, dirty, or musty feeders.
Accordingly, it is an object of this invention to provide a bird feeder that distributes bird feed and is activated by the weight and motion of the feeding birds.
Another object of the invention is to provide a bird feeder that prevents clogging and facilitates free but measured flow of the bird feed.
Another object of the invention is to allow the use of one feeder that will adjust to the different types and sizes of available bird feed.
Another object of the present invention is to provide a bird feeder that can be attached to a variety of feed container sizes.
Still another object of the invention is to provide a self-regulating bird feeder that can easily be attached to and removed from disposable and recyclable feed containers.
A still further object of the invention is to eliminate the need to clean damp or musty feed containers by utilizing recyclable and disposable feed containers.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an animal feeding device made pursuant to one embodiment of the present invention;
FIG. 2 is an exploded view in perspective of the animal feeder illustrated in FIG. 1;
FIG. 3 is a side elevation view, partly in section, of the animal feeder illustrated in FIGS. 1 and 2; and
FIG. 4 is a view similar to FIG. 3 but illustrating the manner in which feed is dispensed from the container of the feeder to the platform thereof in response to a feeding bird.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment herein described is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is chosen and described to explain the principles of the invention and its application and practical use to best enable others skilled in the art to follow its teachings.
Referring now to the drawings, a bird feeder generally indicated by the numeral 10 includes a feed container 11 adapted from a common two liter beverage container. A suspension wire 12 is inserted in suspension holes 14 which are punched on opposite sides of the container 11, to enable the feeder 10 to be suspended from an overhead support with the container 11 oriented in an inverted substantially vertical position. As shown in FIG. 2, the container 11 includes a neck 16 terminating in an opening 18. Accordingly, the container 11 may be filled prior to use by placing it in an upright position so that the neck 16 is pointing upward. The container 11 is then filled with animal feed through the opening 18 using a funnel or similar instrument to ease filling. As shown in FIGS. 3 and 4, feed is dispensed onto a platform 24 which also supports birds using the feeder 10.
As shown in FIG. 2, the platform 24 includes a rim 25 for maintaining feed on the platform. A substantially cylindrical dispersal member 22 includes ends 28 and 30 and a circumferentially extending outer surface 32. An aperture 34 extends through dispersal member 22 and registers with an aperture 26 in platform 24 to receive an elongated threaded rod 36 which extends through lock washer 38, plate washer 40, apertures 26 and 34, plate washer 42 and lock washer 44. Nut 46 tightly clamps end 30 of member 22 against the platform 24, with the remainder of threaded rod 36 projecting from end 28 of member 22.
The outer surface 32 of member 22 frictionally engages the interior of end portion 47 of regulating spring 48. Regulating spring 48 is of coil spring construction, with adjacent coils of regulating spring 48 defining dispensing openings 50 therebetween. The interior of opposite end portion 49 of spring 48 frictionally engages circumferentially extending outer surface 57 of one end portion 53 of flow housing 52. The outer surface 57 of the other end portion 54 of flow housing 52 frictionally engages the interior surface of opening 18 in neck 16 of container 11 so that the surface 58 of a collar 56 contacts the end of neck 16. Flow housing 52 defines a conveyance passage 55 through which feed is transferred from the container 11 to the feeding birds. The end 59 of threaded rod 36 extends coaxially through spring 48, conveyance passage 55 of housing 52, and through opening 18 and into interior of container 11, as shown in FIG. 3.
In operation, as illustrated in FIGS. 3 and 4, a bird lands on the platform 24 and perches on the rim 25. In response to the weight and motion of the bird, the spring 48 permits the platform 24 to rotate about a generally horizontal axis while the container 11 remains in a substantially vertical position. As the platform 24 moves, the agitator rod 36 also moves relative to the container 11. The agitator rod 36 disturbs the feed in the container 11, and the feed flows from the container 11 down through conveyance passage 55 of flow housing 52. The feed enters the interior of the regulating spring 48 and then contacts the upper portion 28 of member 32 and thus falls downward and outward through the dispensing openings 50 in the regulating spring 48 and onto the platform 24. To adjust the flow rate of the feed, the platform 24 may be rotated about a vertical axis so that the regulating spring 48 coacts with the edges of the washer 42 to draw the dispersal member 32 further into the end portion 47 of spring 48. Similarly, the regulating spring 48 may be rotated so that the end portion 53 of housing 52 is drawn further into end portion 49 of spring 48. Accordingly the gap between the end 53 of housing 52 and the end 28 of member 22 may be increased or decreased thus increasing or decreasing the flow of feed.
It is possible to further adjust the flow rate of the feed by varying the shape of the upper surface 28 of member 22. For example, the upper surface 28 may be conical or hemispherical in shape in order to accommodate different sizes of bird feed, or to increase or decrease the flow rate as desired. Alternatively, member 22 can be omitted entirely, by attaching the lower portion 47 of spring 48 directly to the platform 24.
To assemble the bird feeder 10, the container is filled as outlined above. With neck 16 pointing upward, housing 52 is inserted into opening 18 in neck 16 of container i 1. To achieve full insertion, collar 56 provides leverage so that surface 58 of housing 52 contacts the end of neck 18. End 59 of agitator rod 36 is inserted through the lock washer 38, plate washer 40, mounting hole 25 of the platform 24, mounting hole 34 of member 32, and plate washer 42 and lock washer 44. Nut 46 is threaded on rod 36 to clamp dispersal member 32 tight against platform 24, so that agitator rod 36 is generally vertical. Lower portion 47 of spring 48 is frictionally engaged over outer surface 32 of member 22, and spring 48 is rotated clockwise to achieve the desired insertion of member 32 into spring 48. End portion 49 of spring 48 is frictionally engaged over end portion 53 of housing 52, rotating clockwise to achieve full insertion. The entire feeder is then inverted and suspended from a branch or support using wire 12 as shown in FIGS. 3 and 4.
It is understood that the above description does not limit the invention to the above-given details, but may be modified within the scope of the following claims.
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A bird feeder that dispenses feed according to the weight and motion of feeding birds. The movement of feeding birds dispenses the proper amount of feed from the feed container, and the feeder adjusts to accommodate the type of feed being used and the weight and number of birds using the feeder. The feed container is adapted from a common two liter beverage container, which can simply be recycled when it becomes damp or dirty.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority of U.S. Provisional Application Nos. 60/176,293, filed Jan. 18, 2000 and 60/204,590, filed May 16, 2000.
BACKGROUND OF THE INVENTION
The invention generally relates to small, conformationally-constrained peptide inhibitors of members of the VEGF family of compounds. Specifically, the invention provides a purified monomeric monocyclic peptide inhibitor and a purified dimeric bicyclic peptide inhibitor, both based on loop 1, 2 or 3 of VEFG-D as well as methods of making them. The invention also relates to pharmaceutical compositions and methods utilizing these peptide inhibitors.
The two major components of the mammalian vascular system are the endothelial and smooth muscle cells. The endothelial cells form the lining of the inner surface of all blood vessels and lymphatic vessels in the mammal. The formation of new blood vessels can occur by two different processes, vasculogenesis or angiogenesis (for review see Risau, W., Nature 386: 671–674, 1997). Vasculogenesis is characterized by in situ differentiation of endothelial cell precursors to mature endothelial cells and association of these cells to form vessels, such as occurs in the formation of the primary vascular plexus in the early embryo. In contrast, angiogenesis, the formation of blood vessels by growth and branching of pre-existing vessels, is important in later embryogenesis and is responsible for the blood vessel growth which occurs in the adult. Angiogenesis is a physiologically complex process involving proliferation of endothelial cells, degradation of extracellular matrix, branching of vessels and subsequent cell adhesion events. In the adult, angiogenesis is tightly controlled and limited under normal circumstances to the female reproductive system. However angiogenesis can be switched on in response to tissue damage. Importantly, solid tumors are able to induce angiogenesis in surrounding tissue, thus sustaining tumor growth and facilitating the formation of metastases (Folkman, J., Nature Med. 1: 27–31, 1995). The molecular mechanisms underlying the complex angiogenic processes are far from being understood.
Angiogenesis is also involved in a number of pathological conditions, where it plays a role or is involved directly in different sequelae of the disease. Some examples include neovascularization associated with various liver diseases, neovascular sequelae of diabetes, neovascular sequelae to hypertension, neovascularization in post-trauma, neovascularization due to head trauma, neovascularization in chronic liver infection (e.g. chronic hepatitis), neovascularization due to heat or cold trauma, dysfunction related to excess of hormone, creation of hemangiomas and restenosis following angioplasty. In arthritis, the pathological condition occurs because new capillaries invade the joint and destroy the cartilage. In diabetes, one pathological condition is caused by new capillaries in the retina invading the vitreous humour, causing bleeding and blindness (Folkman and Shing, J. Biol. Chem. 267:10931–10934, 1992). The role of angiogenic factors in these and other diseases has not yet been clearly established.
Because of the crucial role of angiogenesis in so many physiological and pathological processes, factors involved in the control of angiogenesis have been intensively investigated. A number of growth factors have been shown to be involved in the regulation of angiogenesis. These include the fibroblast growth factors (FGFs) the platelet-derived growth factors (PDGFs), the transforming growth factor alpha (TGFα), and the hepatocyte growth factor (HGF). See for example Folkman et al., J. Biol. Chem., 267: 10931–10934, 1992 for a review.
It has been suggested that a particular family of endothelial cell-specific growth factors, the vascular endothelial growth factors (VEGFs), and their corresponding receptors are primarily responsible for stimulation of endothelial cell growth and differentiation and for certain functions of the differentiated cells. These factors are members of the PDGF/VEGF family, and appear to act primarily via endothelial receptor tyrosine kinases (RTKs). The PDGF/VEGF family of growth factors belongs to the cystine-knot superfamily of growth factors, which also includes the neurotrophins and transforming growth factor-β.
Eight different proteins have been identified in the PDGF/VEGF family, namely two PDGFs (A and B), VEGF and five members that are closely related to VEGF. The five members closely related to VEGF are: VEGF-B, described in International Patent Application PCT/US96/02957 (WO 96/26736) and in U.S. Pat. Nos. 5,840,693 and 5,607,918 by Ludwig Institute for Cancer Research and The University of Helsinki; VEGF-C or VEGF2, described in Joukov et al., EMBO J., 15: 290–298, 1996, Lee et al., Proc. Natl. Acad. Sci. USA, 93: 1988–1992, 1996, and U.S. Pat. Nos. 5,932,540 and 5,935,540 by Human Genome Sciences, Inc; VEGF-D, described in International Patent Application No. PCT/US97/14696 (WO 98/07832), and Achen et al., Proc. Natl. Acad. Sci. USA, 95: 548–553, 1998; the placenta growth factor (PlGF), described in Maglione et al., Proc. Natl. Acad. Sci. USA, 88: 9267–9271, 1991; and VEGF3, described in International Patent Application No. PCT/US95/07283 (WO 96/39421) by Human Genome Sciences, Inc. Each VEGF family member has between 30% and 45% amino acid sequence identity with VEGF. The VEGF family members share a VEGF homology domain which contains the six cysteine residues which form the cystine-knot motif. Functional characteristics of the VEGF family include varying degrees of mitogenicity for endothelial cells, induction of vascular permeability and angiogenic and lymphangiogenic properties.
Vascular endothelial growth factor (VEGF) is a homodimeric glycoprotein that has been isolated from several sources. Alterative mRNA splicing of a single VEGF gene gives rise to five isoforms of VEGF. VEGF shows highly specific mitogenic activity for endothelial cells. VEGF has important regulatory functions in the formation of new blood vessels during embryonic vasculogenesis and in angiogenesis during adult life (Carmeliet et al., Nature, 380: 435–439, 1996; Ferrara et al., Nature, 380: 439–442, 1996; reviewed in Ferrara and Davis-Smyth, Endocrine Rev., 18: 4–25, 1997). The significance of the role played by VEGF has been demonstrated in studies showing that inactivation of a single VEGF allele results in embryonic lethality due to failed development of the vasculature (Carmeliet et al., Nature, 380: 435–439, 1996; Ferrara et al., Nature, 380: 439–442, 1996). The isolation and properties of VEGF have been reviewed; see Ferrara et al., J. Cellular Biochem., 47: 211–218, 1991 and Connolly, J. Cellular Biochem., 47: 219–223, 1991.
In addition VEGF has strong chemoattractant activity towards monocytes, can induce the plasminogen activator and the plasminogen activator inhibitor in endothelial cells, and can also induce microvascular permeability. Because of the latter activity, it is sometimes referred to as vascular permeability factor (VPF). VEGF is also chemotactic for certain hematopoetic cells. Recent literature indicates that VEGF blocks maturation of dendritic cells and thereby reduces the effectiveness of the immune response to tumors (many tumors secrete VEGF) (Gabrilovich et al., Blood 92: 4150–4166, 1998; Gabrilovich et al., Clinical Cancer Research 5: 2963–2970, 1999).
Vascular endothelial growth factor B (VEGF-B) is very strongly expressed in heart and only weakly in lung, whereas the reverse is the case for VEGF. Reverse transcriptase-polymerase chain reaction (RT-PCR) assays have demonstrated the presence of VEGF-B mRNA in melanoma, normal skin, and muscle. This suggests that VEGF and VEGF-B, despite the fact that they are co-expressed in many tissues, have functional differences. Gene targeting studies have shown that VEGF-B deficiency results in mild cardiac phenotype, and impaired coronary vasculature (Bellomo et al., Circ. Res. 86:E29–35, 2000).
Human VEGF-B was isolated using a yeast co-hybrid interaction trap screening technique by screening for cellular proteins which might interact with cellular retinoic acid-binding protein type I (CRABP-I). The isolation and characteristics including nucleotide and amino acid sequences for both the human and mouse VEGF-B are described in detail in PCT/US96/02957, and in U.S. Pat. Nos. 5,840,693 and 5,607,918 by Ludwig Institute for Cancer Research and The University of Helsinki and in Olofsson et al., Proc. Natl. Acad. Sci. USA, 93: 2576–2581, 1996.
VEGF-C was isolated from conditioned media of the PC-3 prostate adenocarcinoma cell line (CRL1435) by screening for ability of the medium to produce tyrosine phosphorylation of the endothelial cell-specific receptor tyrosine kinase VEGFR-3 (Flt4), using cells transfected to express VEGFR-3. VEGF-C was purified using affinity chromatography with recombinant VEGFR-3, and was cloned from a PC-3 cDNA library. Its isolation and characteristics are described in detail in Joukov et al., EMBO J., 15: 290–298, 1996.
VEGF-D was isolated from a human breast cDNA library, commercially available from Clontech, by screening with an expressed sequence tag obtained from a human cDNA library designated “Soares Breast 3NbHBst” as a hybridization probe (Achen et al., Proc. Natl. Acad. Sci. USA, 95: 548–553, 1938). Its isolation and characteristics are described in detail in International Patent Application No. PCT/US97/14696 (WO98/07832)
In PCT/US97/14696, the isolation of a biologically active fragment of VEGF-D, designated VEGF-DΔNΔC, is also described. This fragment consists of VEGF-D amino acid residues 93 to 201 linked to the affinity tag peptide FLAG®. The entire disclosure of the International Patent Application PCT/US97/14696 (WO 98/07832) is incorporated herein by reference.
The VEGF-D gene is broadly expressed in the adult human, but is certainly not ubiquitously expressed. VEGF-D is strongly expressed in heart, lung and skeletal muscle. Intermediate levels of VEGF-D are expressed in spleen, ovary, small intestine and colon, and a lower expression occurs in kidney, pancreas, thymus, prostate and testis. No VEGF-D mRNA was detected in RNA from brain, placenta, liver or peripheral blood leukocytes.
PlGF was isolated from a term placenta cDNA library. Its isolation and characteristics are described in detail in Maglione et al., Proc. Natl. Acad. Sci. USA, 88: 9267–9271, 1991. Presently its biological function is not well understood.
VEGF3 was isolated from a cDNA library derived from colon tissue. VEGF3 is stated to have about 36% identity and 66% similarity to VEGF. The method of isolation of the gene encoding VEGF3 is unclear and no characterization of the biological activity is disclosed.
Similarity between two proteins is determined by comparing the amino acid sequence and conserved amino acid substitutions of one of the proteins to the sequence of the second protein, whereas identity is determined without including the conserved amino acid substitutions.
A major function of the lymphatic system is to provide fluid return from tissues and to transport many extravascular substances back to the blood. In addition, during the process of maturation, lymphocytes leave the blood, migrate through lymphoid organs and other tissues, enter the lymphatic vessels, and return to the blood through the thoracic duct. Specialized venules, high endothelial venules (HEVs), bind lymphocytes again and cause their extravasation into tissues. The lymphatic vessels, and especially the lymph nodes, thus play an important role in immunology and in the development of metastasis of different tumors. Unlike blood vessels, the embryonic origin of the lymphatic system is not clear, and at least three different theories exist as to its origin. Lymphatic vessels are difficult to identify due to the absence of known specific markers available for them.
Lymphatic vessels are most commonly studied with the aid of lymphography. In lymphography, X-ray contrast medium is injected directly into a lymphatic vessel. The contrast medium gets distributed along the efferent drainage vessels of the lymphatic system and is collected in the lymph nodes. The contrast medium can stay for up to half a year in the lymph nodes, during which time X-ray analyses allow the follow-up of lymph node size and architecture. This diagnostic technique is especially important in cancer patients with metastases in the lymph nodes and in lymphatic malignancies, such as lymphoma. However, improved materials and methods for imaging lymphatic tissues are needed in the art.
As noted above, the PDGF/VEGF family members act primarily by binding to receptor tyrosine kinases. In general, receptor tyrosine kinases are glycoproteins which comprise an extracellular domain capable of binding a specific growth factor(s), a transmembrane domain, which is usually an alpha-helical portion of the protein, a juxtamembrane domain, which is where the receptor may be regulated by, e.g., protein phosphorylation, a tyrosine kinase domain, which is the enzymatic component of the receptor, and a carboxy-terminal tail, which in many receptors is involved in recognition and binding of the substrates for the tyrosine kinase.
Five endothelial cell-specific receptor tyrosine kinases have been identified, belonging to two distinct subclasses: three vascular endothelial cell growth factor receptors, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt4), and the two receptors of the Tie family, Tie and Tie-2 (Tek). These receptors differ in their specificity and affinity. All of these have the intrinsic tyrosine kinase activity which is necessary for signal transduction.
The only receptor tyrosine kinases known to bind VEGFs are VEGFR-1, VEGFR-2 and VEGFR-3. VEGFR-1 and VEGFR-2 bind VEGF with high affinity, and VEGFR-1 also binds VEGF-B and PlGF. VEGF-C has been shown to be the ligand for VEGFR-3, and it also activates VEGFR-2 (Joukov et al., The EMBO Journal, 15: 290–298, 1996) . VEGF-D binds to both VEGFR-2 and VEGFR-3. A ligand for Tek/Tie-2 has been described in International Patent Application No. PCT/US95/12935 (WO 96/11269) by Regeneron Pharmaceuticals, Inc. The ligand for Tie has not yet been identified.
Recently, a novel 130–135 kDa VEGF isoform specific receptor has been purified and cloned (Soker et al., Cell, 92: 735–745, 1998). The VEGF receptor was found to specifically bind the VEGF 165 isoform via the exon 7 encoded sequence, which shows weak affinity for heparin (Soker et al., Cell, 92: 735-745, 1998). surprisingly, the receptor was shown to be identical to human neuropilin-1 (NP-1), a receptor involved in early stage neuromorphogenesis. PlGF-2 also appears to interact with NP-1 (Migdal et al., J. Biol. Chem., 273: 22272–22278, 1998).
VEGFR-1, VEGFR-2 and VEGFR-3 are expressed differently by endothelial cells. Generally, both VEGFR-1 and VEGFR-2 are expressed in blood vessel endothelia (Oelrichs et al., Oncogene, 8: 11–18, 1992; Kaipainen et al., J. Exp. Med., 178: 2077–2088, 1993; Dumont et al., Dev. Dyn., 203: 80–92, 1995; Fong et al., Dev. Dyn., 207: 1–10, 1996), and VEGFR-3 is mostly expressed in the lymphatic endothelium of adult tissues (Kaipainen et al., Proc. Natl. Acad. Sci. USA, 9: 3566–3570, 1995). VEGFR-3 is also expressed in the blood vasculature surrounding tumors.
Although VEGFR-1 is mainly expressed in endothelial cells during development, it can also be found in hematopoetic precursor cells during early stages of embryogenesis (Fong et al., Nature, 376: 66–70, 1995). In adults, monocytes and macrophages also express this receptor (Barleon et al., Blood, 87: 3336–3343, 1995). In embryos, VEGFR-1 is expressed by most, if not all, vessels (Breier et al., Dev. Dyn., 204: 228–239, 1995; Fong et al., Dev. Dyn., 207: 1–10, 1996).
The receptor VEGFR-3 is widely expressed on endothelial cells during early embryonic development, but as embryogenesis proceeds becomes restricted to venous endothelium and then to the lymphatic endothelium (Kaipainen et al., Cancer Res., 54: 6571–6577, 1994; Kaipainen et al., Proc. Natl. Acad. Sci. USA, 92: 3566–3570, 1995). VEGFR-3 is expressed on lymphatic endothelial cells in adult tissues. This receptor is essential for vascular development during embryogenesis.
The essential, specific role in vasculogenesis, angiogenesis and/or lymphangiogenesis of VEGFR-1, VEGFR-2, VEGFR-3, Tie and Tek/Tie-2 has been demonstrated by targeted mutations inactivating these receptors in mouse embryos. Disruption of the VEGFR genes results in aberrant development of the vasculature leading to embryonic lethality around midgestation.
Analysis of embryos carrying a completely inactivated VEGFR-1 gene suggests that this receptor is required for functional organization of the endothelium (Fong et al., Nature, 376: 66–70, 1995). However, deletion of the intracellular tyrosine kinase domain of VEGFR-1 generates viable mice with a normal vasculature (Hiratsuka et al., Proc. Natl. Acad. Sci. USA, 95: 9349–9354, 1998). The reasons underlying these differences remain to be explained but suggest that receptor signalling via the tyrosine kinase is not required for the proper function of VEGFR-1.
Analysis of homozygous mice with inactivated alleles of VEGFR-2 suggests that this receptor is required for endothelial cell proliferation, hematopoesis and vasculogenesis (Shalaby et al., Nature, 376: 62–66, 1995; Shalaby et al., Cell, 89: 981–990, 1997).
Targeted inactivation of both copies of the VEGFR-3 gene in mice resulted in defective blood vessel formation characterized by abnormally organized large vessels with defective lumens, leading to fluid accumulation in the pericardial cavity and cardiovascular failure at post-coital day 9.5 (Dumont et al., Science, 282: 946–949, 1998). On the basis of these findings, it has been proposed that VEGFR-3 is required for the maturation of primary vascular networks into larger blood vessels. However, the role of VEGFR-3 in the development of the lymphatic vasculature could not be studied in these mice because the embryos died before the lymphatic system emerged. Nevertheless it is assumed that VEGFR-3 plays a role in development of the lymphatic vasculature and lymphangiogenesis given its specific expression in lymphatic endothelial cells during embryogenesis and adult life. This is supported by the finding that ectopic expression of VEGF-C, a ligand for VEGFR-3, in the skin of transgenic mice, resulted in lymphatic endothelial cell proliferation and vessel enlargement in the dermis. Furthermore this suggests that VEGF-C may have a primary function in lymphatic endothelium, and a secondary function in angiogenesis and permeability regulation which is shared with VEGF (Joukov et al., EMBO J., 15: 290–298, 1996).
In addition, VEGF-like proteins have been identified which are encoded by four different strains of the orf virus. This is the first virus reported to encode a VEGF-like protein. The first two strains are NZ2 and NZ7, and are described in Lyttle et al., J. Virol., 68: 84–92, 1994. A third is D1701 and is described in Meyer et al., EMBO J., 18: 363–374, 1999. The fourth strain is NZ10 and is described in International Patent Application PCT/US99/25869. It was shown that these viral VEGF-like proteins bind to VEGFR-2 on the endothelium of the host (sheep/goat/human) (Meyer et al., EMBO J., 18: 363–374, 1999; and Ogawa et al. J. Biol. Chem., 273: 31273–31282, 1988) and this binding is important for development of infection (International Patent Application PCT/US99/25869). The entire disclosure of the International Patent Application PCT/US99/25869 is incorporated herein by reference. These proteins show amino acid sequence similarity to VEGF and to each other.
The orf virus is a type of species of the parapoxvirus genus which causes a highly contagious pustular dermatitis in sheep and goats and is readily transmittable to humans. The pustular dermatitis induced by orf virus infection is characterized by dilation of blood vessels, swelling of the local area and marked proliferation of endothelial cells lining the blood vessels. These features are seen in all species infected by orf and can result in the formation of a tumor-like growth or nodule due to viral replication in epidermal cells. Generally orf virus infections resolve in a few weeks, but severe infections that fail to resolve without surgical intervention are seen in immune impaired individuals.
The biological functions of the different members of the VEGF family are currently being elucidated. Of particular interest are the properties of VEGF-D and VEGF-C. These proteins bind to both VEGFR-2 and VEGFR-3—localized on vascular and lymphatic endothelial cells respectively—and are closely related in primary structure (48% amino acid identity) Both factors are mitogenic for endothelial cells in vitro.
VEGF-C has been shown to be angiogenic in the mouse cornea model and in the avian chorioallantoic membrane (Cao et al., Proc. Natl. Acad. Sci. USA 95: 14389–14394, 1998) and was able to induce angiogenesis in the setting of tissue ischemia (Witzenbichler et al., Am. J. Pathol. 153: 381–394, 1998). Furthermore, VEGF-C stimulated lymphangiogenesis in the avian chorioallantoic membrane (Oh et al. , Dev. Biol. 188: 96–109, 1997) and in a transgenic mouse model (Jeltsch et al., Science 276: 1423–1425, 1997).
VEGF-D was shown to be angiogenic in the rabbit cornea (Marconcini et al., Proc. Natl. Acad. Sci. USA 96: 9671–9676, 1999) The lymphangiogenic capacity of VEGF-D has not yet been reported, however, given that VEGF-D, like VEGF-C, binds and activates VEGFR-3, a receptor thought to signal for lymphangiogenesis (Taipale et al. , Curr. Topics Micro. Immunol. 237: 85–96, 1999), it is highly likely that VEGF-D is lymphangiogenic.
VEGF-D and VEGF-C may be of particular importance for the malignancy of tumors, as metastases can spread via either blood vessels or lymphatic vessels; therefore molecules which stimulate angiogenesis or lymphangiogenesis could contribute toward malignancy. This has already been shown to be the case for VEGF. It is noteworthy that VEGF-D gene expression is induced by c-Fos, a transcription factor known to be important for malignancy (Orlandini et al., Proc. Natl. Acad. Sci. USA 93: 11675–11680, 1996). It has been speculated that the mechanism by which c-Fos contributes to malignancy is the up-regulation of genes encoding angiogenic factors.
Each monomer of the VEGF dimer resembles other cystine-knot proteins, having an elongated structure consisting of pairs of twisted, anti-parallel β-strands connected by a series of solvent-exposed loops. The crystal structure of the complex between VEGF and the immunoglobulin-like domain 2 of VEGFR-1 (Wiesmann et al., Cell 91: 695–704, 1997) and mutational analyses (Muller et al., Proc. Natl. Acad. Sci. USA 94: 7192–7197, 1997; Keyt et al., J. Biol. Chem. 271: 5638–5646, 1996) of VEGF indicate that residues important for binding of this molecule to its receptors VEGFR-1 and VEGFR-2 are located primarily on the solvent-exposed loops at the ends of each monomer. The VEGF monomers associate to form disulfide-linked dimers in a side-by-side, head-to-tail fashion, thus creating two symmetrical clusters of receptor binding residues, one at each “pole” of the VEGF dimer.
There is great interest in the development of pharmacological agents which antagonize the receptor-mediated actions of VEGFs (Martiny-Baron and Marme, Curr. Opin. Biotechnol. 6: 675–680, 1995). Monoclonal antibodies to VEGF have been shown to suppress tumor growth in vivo by inhibiting tumor-associated angiogenesis (Kim et al., Nature 362: 841–844, 1993). Similar inhibitory effects on tumor growth have been observed in model systems resulting from expression of either antisense RNA for VEGF (Saleh et al., Cancer Res. 56: 393–401, 1996) or a dominant-negative VEGFR-2 mutant (Millauer et al., Nature 367: 576–579, 1994). While indicating the potential of interfering with the VEGF signalling system as a chemotherapeutic approach, these approaches—being protein- and DNA-based—are not optimal given current pharmaceutical delivery technologies. The development of small molecule antagonists of members of the VEGF family would offer distinct advantages over protein- and DNA-based strategies in terms of oral absorption, penetration across cell membranes, bioavailabilty and biological half life.
SUMMARY OF THE INVENTION
This invention relates to purified monomeric monocyclic peptide inhibitors and purified dimeric bicyclic peptide inhibitors, both based on the peptide sequences of exposed loops of growth factor proteins, such as loops 1, 2 and 3 of VEGF-D, as well as to methods of making them. The invention also relates to pharmaceutical compositions and methods utilizing these peptide inhibitors.
According to one aspect, the invention provides a monomeric monocyclic peptide inhibitor based on loop 1, 2 or 3 of VEGF-D. A preferred peptide interferes with at least the activity of VEGF-D and VEGF-C mediated by VEGF receptor-2 and VEGF receptor-3 (VEGFR-3). A particularly preferred peptide interferes with the activity of VEGF-D, VEGF-C and VEGF mediated by VEGFR-2 and the activity of VEGF-D and VEGF-C mediated by VEGFR-3.
According to another aspect, the invention provides a dimeric bicyclic peptide inhibitor which comprises two monomeric monocyclic peptides, each individually based on loop 1, 2 or 3 of VEGF-D, linked together. A dimeric bicyclic peptide may comprise two monomeric monocyclic peptides which are the same or which are different.
It is also an aspect of the invention to provide a method of making a monomeric monocyclic peptide of the invention. This method comprises synthesizing a linear peptide based on loop 1, 2 or 3 of VEGF-D which includes spaced cysteine residues, oxidizing the linear peptide to a monomeric monocyclic peptide, and optionally purifying the monomeric monocyclic peptide.
An additional aspect provides a method of making a dimeric bicyclic peptide of the invention. This method comprises synthesizing two linear peptides each individually based on loop 1, 2 or 3 of VEGF-D and including appropriately protected, spaced cysteine residues, oxidizing each of the linear peptides to obtain a partially protected monomeric monocyclic peptide, dimerizing the two partially protected momomeric monocyclic peptides to obtain a dimeric bicyclic peptide, and optionally purifying the dimeric bicyclic peptide.
The skilled person is aware that a peptidomimetic compound can be made in which one or more amino acid residues is replaced by its corresponding D-amino acid, substitutions or modifications are made to one or more amino acids in the sequence, peptide bonds can be replaced by a structure more resistant to metabolic degradation and different cyclizing constraints and dimerization groups can be incorporated.
With respect to compounds in which one or more amino acids is replaced by its corresponding D-amino acid, the skilled person is aware that retro-inverso amino acid sequences can be synthesized by standard methods; see, for example, Chorev and Goodman, Acc. Chem. Res., 26: 266–273, 1993.
Olson et al., J. Med. Chem., 36: 3039–3049 1993 provides an example of replacing a peptide bond with a structure more resistant to metabolic degradation.
Peptidomimetic compounds can also be made where individual amino acids are replaced by analogous structures, for example gem-diaminoalkyl groups or alkylmalonyl groups, with or without modified termini or alkyl, acyl or amine substitutions to modify their charge. The use of such alternative structures can provide significantly longer half-life in the body, since they are more resistant to breakdown under physiological conditions.
Methods for combinatorial synthesis of peptide analogs and for screening of peptides and peptide analogs are well known in the art (see, for example, Gallop et al., J. Med. Chem., 37: 1233–1251, 1994). It is particularly contemplated that the compounds of the invention are useful as templates for design and synthesis of compounds of improved activity, stability and bioavailability.
Preferably where amino acid substitution is used, the substitution is conservative, i.e. an amino acid is replaced by one of similar size and with similar charge properties.
As used herein, the term “conservative substitution” denotes the replacement of an amino acid residue by another, biologically similar residue. Examples of conservative substitutions include the substitution of one hydrophobic residue such as isoleucine, valine, leucine, alanine, cysteine, glycine, phenylalanine, proline, tryptophan, tyrosine, norleucine or methionine for another, or the substitution of one polar residue for another, such as the substitution of arginine for lysine, glutamic acid for aspartic acid, or glutamine for asparagine, and the like. Neutral hydrophilic amino acids which can be substituted for one another include asparagine, glutamine, serine and threonine. The term “conservative substitution” also includes the use of a substituted amino acid in place of an unsubstituted parent amino acid.
As such, it should be understood that in the context of the present invention, a conservative substitution is recognized in the art as a substitution of one amino acid for another amino acid that has similar properties. Exemplary conservative substitutions are set out in the following Table A from WO 97/09433.
TABLE A
Conservative Substitutions I
SIDE CHAIN
CHARACTERISTIC
AMINO ACID
Aliphatic
Non-polar
G A P
I L V
Polar-uncharged
C S T M
N Q
Polar-charged
D E
K R
Aromatic
H F W Y
Other
N Q D E
Alternatively, conservative amino acids can be grouped as described in Lehninger, [Biochemistry, Second Edition; Worth Publishers, Inc. NY:N.Y. (1975), pp.71–77] as set out in the following Table B.
TABLE B
Conservative Substitutions II
SIDE CHAIN
CHARACTERISTIC
AMINO ACID
Non-polar (hydrophobic)
A. Aliphatic:
A L I V P
B. Aromatic:
F W
C. Sulfur-containing:
M
D. Borderline:
G
Uncharged-polar
A. Hydroxyl:
S T Y
B. Amides:
N Q
C. Sulfhydryl:
C
D. Borderline:
G
Positively Charged (Basic):
K R H
Negatively Charged (Acidic):
D E
Exemplary conservative substitutions are set out in the following Table C.
TABLE C
Conservative Substitutions III
Original
Exemplary
Residue
Substitution
Ala (A)
Val, Leu, Ile
Arg (R)
Lys, Gln, Asn
Asn (N)
Gln, His, Lys, Arg
Asp (D)
Glu
Cys (C)
Ser
Gln (Q)
Asn
Glu (E)
Asp
His (H)
Asn, Gln, Lys, Arg
Ile (I)
Leu, Val, Met,
Ala, Phe,
Leu (L)
Ile, Val, Met,
Ala, Phe
Lys (K)
Arg, Gln, Asn
Met (M)
Leu, Phe, Ile
Phe (F)
Leu, Val, Ile, Ala
Pro (P)
Gly
Ser (S)
Thr
Thr (T)
Ser
Trp (W)
Tyr, Phe
Tyr (Y)
Trp, Phe, Thr, Ser
Val (V)
Ile, Leu, Met,
Phe, Ala
If desired, the cyclic peptidomimetic peptides of the invention can be modified, for instance, by glycosylation, amidation, carboxylation, or phosphorylation, or by the creation of acid addition salts, amides, esters, in particular C-terminal esters, and N-acyl derivatives of the peptides of the invention. The peptides also can be modified to create peptide derivatives by forming covalent or noncovalent complexes with other moieties. Covalently-bound complexes can be prepared by linking the chemical moieties to functional groups on the side chains of amino acids comprising the peptides, or at the N- or C-terminus.
In particular, it is anticipated that the aforementioned peptides can be conjugated to a reporter group, including, but not limited to a radiolabel, a fluorescent label, an enzyme (e.g., that catalyzes a calorimetric or fluorometric reaction), a substrate, a solid matrix, or a carrier (e.g., biotin or avidin).
Regarding the cyclizing constraints and dimerization groups, a preferred linking group has 0 to 20 carbon atoms, 0 to 10 heteroatoms (N, O, S, P etc.), straight chain or branched which contain saturated, unsaturated and/or aromatic rings, single and/or double bonds and chemical groups such as amide, ester, disulfide, thioether, ether, phosphate, amine and the like.
The “constraint” used to cyclize the linear peptide can be obtained by several methods, including but not limited to:
(i) cyclizing the N-terminal amine with the C-terminal carboxyl acid function, either directly via an amide bond between the N-terminal nitrogen and C-terminal carbonyl, or indirectly via a spacer group, for example by condensation with an ω-amino carboxylic acid;
(ii) cyclizing via the formation of a covalent bond between the side chains of two residues, such as an amide bond between a lysine residue and either an aspartic acid or glutamic acid residue, or a disulfide bond between two cysteine residues, or a thioether bond between a cysteine residue and an ω-halogenated amino acid residue, either directly or via a spacer group as described in (i) above. The residues contributing the side chains may be derived from the VEGF-D loop sequence itself, or may be incorporated into or added on to the VEGF-D loop sequence for this purpose; and,
(iii) cyclizing via the formation of an amide bond between a side chain (for example of a lysine or aspartate residue) and either the C-terminal carboxyl or N-terminal amine, either directly or using a spacer group as described in (i) above. The residues contributing the side chains may be derived from the VEGF-D loop sequence itself, or may be incorporated into or added on to the VEGF-D loop sequence for this purpose.
A still further aspect of the invention makes use of the ability of a peptide of the invention to suppress or interfere with at least one biological activity induced by at least VEGF-D and/or VEGF-C and mediated by VEGF receptor-2 and/or VEGF receptor-3. Examples of such biological activities include vascular permeability, endothelial cell proliferation, angiogenesis, lymphangiogenesis and endothelial cell differentiation. This method comprises administering an effective biological activity interfering amount of a monomeric monocyclic peptide of the invention or a dimeric bicyclic peptide of the invention.
Clinical applications of the invention include, but are not limited to, suppression or inhibition of angiogenesis and/or lymphangiogenesis in the treatment of cancer, diabetic retinopathy, psoriasis and arthropathies. Thus the invention also relates to a method of interfering with angiogenesis, lymphagiogenesis and/or neovascularization in a mammal in need of such treatment which comprises administering an effective amount of a peptide of the invention to the mammal. The peptide interferes with the action of at least VEGF-D and/or VEGF-C by preventing the activation of at least VEGFR-2 and/or VEGFR-3. The cyclic peptide may also interfere with the action of VEGF in the same way as well as the action of VEGF-like proteins from the orf viruses.
This suppression or inhibition of angiogenesis and/or lymphangiogenesis can also occur by targeting a cell expressing VEGFR-2 and/or VEGFR-3 for death. This would involve coupling a toxic compound to a peptide of the invention in order to kill a cell expressing VEGFR-2 and/or VEGFR-3. Such toxic compounds include, but are not limited to, ricin A chain, diphtheria toxin or radionuclides.
As mentioned earlier VEGF blocks maturation of dendritic cells and thereby reduces the effectiveness of the immune response to tumors and VEGF-D and/or VEGF-C may have a similar activity, mediated by VEGFR-2. Therefore inhibitors of VEGF-D/VEGF-C/VEGF should be of use in modulating the immune response to tumors and in other pathological conditions.
Similarly it has been shown that VEGF is chemotactic for certain hematopoetic cells, and VEGF-D and/or VEGF-C may also have similar activity. Thus, inhibition of this process is useful where it is desirable to prevent accumulation of these hematopoetic cells at a specific location or to enhance this process to attract these hematopoetic cells to a specific location.
In addition, this aspect of the invention provides a method of interfering with at least one biological activity selected from angiogenesis, lymphangiogenesis and neovascularization in a disease in a mammal selected from the group of cancer, diabetic retinopathy, psoriasis and arthropathies, comprising the step of administering to said mammal an effective angiogenesis, lymphangiogenesis or neovascularization interfering amount of a peptide of the invention. As noted above, the peptide interferes with the action of at least VEGF-D and VEGF-C by interfering with the activity of VEGF-D and VEGF-C mediated by VEGFR-2 and/or VEGFR-3. The peptide may also interfere with the activity of VEGF mediated by VEGFR-2.
A peptide of the invention can be also be used to modulate vascular permeability in a mammal. Accordingly, the invention provides a method of modulating vascular permeability in a mammal. The method comprises administering to said mammal an effective vascular permeability modulating amount of a monomeric monocyclic peptide of the invention or a dimeric bicyclic peptide of the invention.
A peptide of the invention can be also be used to treat conditions, such as congestive heart failure, involving accumulations of fluid in, for example, the lung resulting from increases in vascular permeability, by exerting an offsetting effect on vascular permeability in order to counteract the fluid accumulation. Accordingly, the invention provides a method for treating fluid accumulation in the lung(s), peritoneal cavity, pleura, brain and other body cavities and/or the periphery due to increases in vascular permeability in a mammal. The increase in vascular permeability can also be due to allergic disorders. This method comprises administering to said mammal in need of such treatment an effective vascular permeability decreasing amount of a monomeric monocyclic peptide of the invention or a dimeric bicyclic peptide of the invention.
Another aspect of the invention concerns the provision of a pharmaceutical composition comprising a monomeric mononcyclic peptide of the invention or a dimeric bicyclic peptide of the invention, and a pharmaceutically acceptable non-toxic salt thereof, and a pharmaceutically acceptable solid or liquid carrier or adjuvant. A preferred pharmaceutical composition will inhibit or interfere with a biological activity induced by at least VEGF-D and VEGF-C and mediated by at least VEGFR-2 and/or VEGFR-3. A particularly preferred pharmaceutical composition will inhibit the biological activity induced by VEGF-D, VEGF-C and VEGF and mediated by VEGFR-2 and/or VEGFR-3.
Examples of such a carrier or adjuvant include, but are not limited to, saline, buffered saline, Ringer's solution, mineral oil, talc, corn starch, gelatin, lactose, sucrose, microcrystalline cellulose, kaolin, mannitol, dicalcium phosphate, sodium chloride, alginic acid, dextrose, water, glycerol, ethanol, thickeners, stabilizers, suspending agents and combinations thereof. Such compositions may be in the form of solutions, suspensions, tablets, capsules, creams, salves, elixirs, syrups, wafers, ointments or other conventional forms. The formulation is carried out to suit the mode of administration. Compositions comprising a peptide of the invention will contain from about 0.1% to 90% by weight of the active compound(s), and most generally from about 10% to 30%.
The dose(s) and route of administration will depend upon the nature of the patient and condition to be treated, and will be at the discretion of the attending physician or veterinarian. Suitable routes include oral, subcutaneous, intramuscular, intraperitoneal or intravenous injection, parenteral, topical application, implants etc. For example, an effective amount of a monomeric monocyclic peptide of the invention or a dimeric bicyclic peptide of the invention is administered to an organism in need thereof in a dose between about 0.1 and 1000 μg/kg body weight.
The peptidomimetic peptides of the invention may be used as therapeutic compositions either alone or in combination with other therapeutic agents.
Immunotherapeutics, generally, rely on the use of immune effector cells and molecules to target and destroy cancer cells. The immune effector may be, for example, an antibody specific for some marker on the surface of a tumor cell. The antibody alone may serve as an effector of therapy or it may recruit other cells to actually effect cell killing. The antibody also may be conjugated to a drug or toxin (chemotherapeutic, radionuclide, ricin A chain, cholera toxin, pertussis toxin, etc.) and serve merely as a targeting agent. Alternatively, the effector may be a lymphocyte carrying a surface molecule that interacts, either directly or indirectly, with a tumor cell target. Various effector cells include cytotoxic T cells and NK cells.
In the context of the present invention, the peptidomimetic peptides of the present invention may be administered in conjunction with one or more antibodies, antibody conjugates or immune effector cells which target the selected tumor for therapy and that are combined with the immunotherapy and target the vasculature of the tumor to exert a combined therapeutic effect.
Tumor cell resistance to DNA damaging agents represents a major problem in clinical oncology. One goal of current cancer research is to find ways to improve the efficacy of chemo- and radiotherapy. One way is by combining such traditional therapies with gene therapy. For example, the herpes simplex-thymidine kinase (HS-tk) gene, when delivered to brain tumors by a retroviral vector system, successfully induced susceptibility to the antiviral agent ganciclovir (Culver et al., 1992). In the context of the present invention, the peptidomimetic peptides of the present invention may be used similarly in conjunction with chemo- or radiotherapeutic intervention. Peptidomimetic peptide therapy may also be combined with immunotherapy, as described above.
To kill cells, inhibit cell growth, inhibit metastasis, inhibit angiogenesis or otherwise reverse or reduce the malignant phenotype of tumor cells, using the methods and compositions of the present invention, one would generally contact a “target” cell with the therapeutic peptides of the present invention and at least one other agent. These compositions would be provided in a combined amount effective to kill or inhibit proliferation of the cell. This process may involve contacting the cells with the peptidomimetic peptide and the additional agent(s) or factor(s) at the same time. This may be achieved by contacting the cell with a single composition or pharmacological formulation that includes both agents, or by contacting the cell simultaneously with two distinct compositions or formulations, one of which includes the peptidomimetic peptide and the other of which includes the second agent.
Alternatively, the peptidomimetic competitive inhibitor peptide-based therapy treatment may precede or follow the other agent treatment by intervals ranging from minutes to weeks. In embodiments where the other agent and expression construct are applied separately to the cell, it should generally be ensured that a significant period of time does not expire between the time of each delivery, such that the agent and peptidomimetic competitive inhibitor peptide-based therapeutic are still able to exert an advantageously combined effect on the cell. In such instances, it is contemplated that the cell will be contacted with both modalities within about 12–24 hours of each other and, more preferably, within about 6–12 hours of each other, with a delay time of only about 12 hours being most preferred. In some situations, it may be desirable to extend the time period for treatment significantly, however, where several days (2, 3, 4, 5, 6 or 7) to several weeks (1, 2, 3, 4, 5, 6, 7 or 8) lapse between the respective administrations.
Agents or factors suitable for use in a combined therapy include any chemical compound or treatment method that induces DNA damage when applied to a cell. Such agents and factors include radiation and waves that induce DNA damage such as, γ-irradiation, X-rays, UV-irradiation, microwaves, electronic emissions, and the like. A variety of chemical compounds, also described as “chemotherapeutic agents”, function to induce DNA damage, all of which are intended to be of use in the combined treatment methods disclosed herein. Chemotherapeutic agents contemplated to be of use, include, e.g., adriamycin, 5-fluorouracil (5FU), etoposide (VP-16), camptothecin, actinomycin-D, mitomycin C, cisplatin (CDDP) and even hydrogen peroxide. The invention also encompasses the use of a combination of one or more DNA damaging agents, whether radiation-based or actual compounds, such as the use of X-rays with cisplatin or the use of cisplatin with etoposide.
In treating cancer according to the invention, the tumor cells should be contacted with an anti-tumor agent in addition to the peptidomimetic competitive inhibitor peptide-based therapy. This may be achieved by irradiating the localized tumor site with radiation such as X-rays, UV-light, γ-rays or even microwaves. Alternatively, the anti-tumor agent may comprise a therapeutically effective amount of a pharmaceutical compound such as, adriamycin, 5-fluorouracil, etoposide, camptothecin, actinomycin-D, mitomycin C, or cisplatin. The agent may be prepared and used as a combined therapeutic composition, or kit, by combining it with a peptidomimetic inhibitor peptide of the invention, as described above.
Agents that directly cross-link nucleic acids, specifically DNA, are envisaged to facilitate DNA damage leading to a synergistic, antineoplastic combination with peptidomimetic competitive inhibitor peptide-based therapy. Agents such as cisplatin, and other DNA alkylating agents may be used. Cisplatin has been widely used to treat cancer, with efficacious doses used in clinical applications of 20 mg/m 2 for 5 days every three weeks for a total of three courses. Cisplatin is not absorbed orally and must therefore be delivered via injection intravenously, subcutaneously, intratumorally or intraperitoneally.
Agents that damage DNA also include compounds that interfere with DNA replication, mitosis and chromosomal segregation. Such chemotherapeutic compounds include adriamycin, also known as doxorubicin, etoposide, verapamil, podophyllotoxin, and the like. Widely used in a clinical setting for the treatment of neoplasms, these compounds are administered through bolus injections intravenously at doses ranging from 25–75 mg/m 2 at 21 day intervals for adriamycin, to 35–50 mg/m 2 for etoposide intravenously or double the intravenous dose orally.
Additionally, as mentioned above, the peptidomimetic peptides of the present invention may prove effective in alleviating the symptoms of chronic inflammatory diseases, rheumatoid arthritis, psoriasis and diabetic retinopathy. It is contemplated that the peptides of the instant invention may be combined with traditional anti-inflammatory and other agents that are used in the management of these disorders.
A further aspect of the invention relates to a method for imaging of blood vessels and lymphatic vasculature. This method comprises applying a peptide of the invention to a sample to be imaged; allowing the peptide to bind to a cell surface receptor; and imaging the binding by any suitable means.
The peptide can be directly labeled or indirectly labeled through use of, for example, an antibody to the peptide. The peptide or antibody may be coupled to a suitable supermagnetic, paramagnetic, electron dense, ecogenic or radioactive or non-radioactive agent for imaging. Examples of radioactive agents/labels include a radioactive atom or group, such as 125 I or 32 P. Examples of non-radioactive agents/labels include enzymatic labels, such as horseradish peroxidase or fluorimetric labels, such as fluorescein-5-isothiocyanate (FITC) as well as fluorescent conjugates, such as fluorescent-gold conjugates. Labeling may be direct or indirect, covalent or non-covalent. Images can be obtained from such medical imaging techniques as fluorescence imaging microscopy, magnetic resonance imaging or electron imaging microscopy.
The cyclic monomeric or dimeric peptidomimetic inhibitors of the invention may also be used, for example, to suppress corpus luteum angiogenesis and to treat angiogenesis-related disorders of the female reproductive tract, e.g. endometriosis, ovarian hyperstimulation syndrome, or conditions characterized by ovarian hyperplasia and hypervascularity, such as polycystic ovary syndrome.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the backbone trace of the three dimensional structure of the VEGF-D dimer showing the positions of the putative receptor binding loops 1, 2 and 3.
FIG. 2 shows a scheme useful to make monomeric monocyclic peptides according to the invention.
FIGS. 3 a–c show the effects of peptide 1 ( 3 a ), peptide 2 ( 3 b ) and peptide 3 ( 3 c ), respectively, on VEGF-D mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 4 a–c show the effects of peptide 1 ( 4 a ), peptide 2 ( 4 b ) and peptide 3 ( 4 c ), respectively, on VEGF mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 5 a–c show the effects of peptide 1 ( 5 a ), peptide 2 ( 5 b ) and peptide 3 ( 5 c ), respectively, on IL-3 mediated cell survival/proliferation in the VEGFR-2 bioassay after 48 hours in culture.
FIG. 6 shows a backbone trace of the predicted three dimensional structure of loop 1 of VEGF-D (contributed by one monomer) and loop 2 of VEGF-D (contributed by the other monomer).
FIG. 7 shows a scheme useful to make dimeric bicyclic peptides according to the invention.
FIGS. 8 a–b show an HPLC trace of samples taken from the dimerization reaction of Acm-protected loop 1 and loop 2 monomers two minutes ( 8 a ) and three hours ( 8 b ), respectively, after commencing the reaction.
FIGS. 9 a–c show the effects of peptide 4 ( 9 a ), peptide 5 ( 9 b ) and peptide 6 ( 9 c ), respectively, on VEGF-D mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 10 a–c show the effects of peptide 4 ( 10 a ), peptide 5 ( 10 b ) and peptide 6 ( 10 c ), respectively, on VEGF mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 11 a–c shows the effects of peptide 4 ( 11 a ), peptide 5 ( 11 b ) and peptide 6 ( 11 c ), respectively, on IL-3 mediated cell survival/proliferation in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 12 a–c show the effects of peptide 1 ( 12 a ), peptide 2 ( 12 b ) and peptide 3 ( 12 c ), respectively, on VEGF-D mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 13 a–c show the effects of peptide 4 ( 13 a ), peptide 5 ( 13 b ) and peptide 6 ( 13 c ), respectively, on VEGF-D mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 14 a–c show the effects of peptide 1 ( 14 a ), peptide 2 ( 14 b ) and peptide 3 ( 14 c ), respectively, on VEGF-C mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 15 a–c show the effects of peptide 4 ( 15 a ), peptide 5 ( 15 b ) and peptide 6 ( 15 c ), respectively, on VEGF-C mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 16 a–c show the effects of peptide 1 ( 16 a ), peptide 2 ( 16 b ) and peptide 3 ( 16 c ), respectively, on VEGF-C mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 17 a–c show the effects of peptide 4 ( 17 a ), peptide 5 ( 17 b ) and peptide 6 ( 17 c ), respectively, on VEGF-C mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 18 a–c show the effects of peptide 7 ( 18 a ), peptide 8 ( 18 b ) and peptide 9 ( 18 c ), respectively, on VEGF mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 19 a–b show the effects of peptide 7 against cell survival mediated by VEGF-C ( 19 a ) and VEGF-D ( 19 b ), respectively, in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 20 a–b show the effects of peptides 7 ( 20 a ) and peptide 9 ( 20 b ), respectively, on VEGF-C mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 21 a–b show the effects of peptides 7 ( 21 a ) and peptide 9 ( 21 b ), respectively, on VEGF-D mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 22 a–c show the effects of peptide 7 ( 22 a ), peptide 8 ( 22 b ) and peptide 9 ( 22 c ), respectively, on IL-3 mediated cell survival/proliferation in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 23 a–b show the effects of peptides 10 ( 23 a ) and 11 ( 23 b ), respectively, on VEGF mediated cell survival in the VEGFR-2 bioassay after 48 hours in culture.
FIGS. 24 a–b show the effects of peptides 10 ( 24 a ) and 11 ( 24 b ), respectively, on VEGF-C mediated cell survival in the VEGFR-3 bioassay after 48 hours in culture.
FIGS. 25 a–b show the effects of peptides 10 ( 25 a ) and 11 ( 25 b ), respectively, on IL-3 mediated cell survival/proliferation in the VEGFR-2 bioassay after 48 hours in culture.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Example 1
Homology Modelling of VEGF-D
A model of the three dimensional (3D) structure of human VEGF-D [amino acids Val 101 —Pro 196 (SEQ ID NO:1), which correspond to Lys 42 —Asp 135 of human VEGF (SEQ ID NO:2)] was obtained using protein homology modelling techniques from the known 3D structure of the VEGF dimer. Previously these methods were used to develop a model of the 3D structure of brain-derived neurotrophic factor (BDNF), which was then used successfully in the molecular design of BDNF antagonists (O'Leary and Hughes, J. Neurochem. 70: 1712–1721, 1998) and agonists (Australian Provisional Patent Application PQ0848).
Initial homology modelling for VEGF-D was carried out using the Swiss-Model automated protein homology server running at the Glaxo Institute for Molecular Biology in Geneva, Switzerland, accessed via the Internet (See Peitsch, 1995). In the C-terminal 23 amino acid residues of the sequences used for modeling there is low homology between VEGF-D and VEGF. Therefore a theoretical hybrid molecule was generated whose N-terminus consists of amino acids Val 101 —Thr 173 of VEGF-D (SEQ ID NO:3) and whose C-terminus consists of Gln 113 —Asp 135 of VEGF 165 (SEQ ID NO:4). Thus the C-terminal 23 residues of VEGF-D were replaced with the corresponding residues of VEGF. A homology model of this hybrid molecule was then generated using an X-ray crystal structure of the VEGF dimer (Brookhaven Protein Database reference 2VPF) as a template. The resultant model was transferred to the molecular modelling software Sybyl (Tripos Inc. St. Louis, USA), and the C-terminal residues manually mutated to those found in VEGF-D. The VEGF-D diner was then minimized (Sybyl forcefield, Powell conjugate gradient minimization, 1000 cycles) to produce the final VEGF-D diner model, as shown in FIG. 1 .
Example 2
Molecular Design of Monomeric Monocyclic Mimetics of Receptor Binding Loops of VEGF-D
From the model of VEGF-D described in Example 1, the putative receptor binding loops 1, 2 and 3 were examined in Sybyl for suitable places to insert a molecular constraint to create monomeric monocyclic peptides which mimic the conformation of each of the native loops. To do this, beta beta carbon distances were measured on opposing antiparallel strands in each loop. Beta beta carbon atom distances of less than 6 Å were deemed suitable for the insertion of a disulfide constraint via a cystine residue. Cysteine residues were inserted at these positions and oxidized to form a cystine cyclizing constraint. The resulting monomeric monocyclic peptides were minimized and compared to the corresponding native loop in the VEGF-D dimer model. On the basis of their energy and similarity to the corresponding native loop, the three monomeric monocyclic peptides 1, 2 and 3 based on loops 1, 2 and 3 of VEGF-D were chosen for synthesis.
Example 3
Synthesis of Monomeric Monocyclic Mimetics of Receptor Binding Loops of VEGF-D
As illustrated in FIG. 2 , the linear peptide precursors to peptides 1, 2 and 3 were assembled from fluorenyl methoxycarbonyl (Fmoc) amino acids manually on chlorotrityl resin (Barlos et al, Int. J. Peptide Protein Res. 37: 513–520, 1991) using the batch-type solid phase methods described in Fields and Noble, Int. J. Peptide Protein Res. 35: 161–214, 1990. Standard side chain protecting groups were used, including trityl (Trt) protection for the terminal cysteine (Cys) residues. The linear free acids were cleaved from the resin using trifluoracetic acid (TFA)/ethanedithiol (EDT)/H 2 O (18:1:1). Other abbreviations found in FIG. 2 are:
HBTU: O-benzotriazol-1-yl-N,N,N,N′,N′-tetramethyluronium hexafluorophosphate, HOBT: 1-hydroxybenzotriazole, DIPEA: diisopropylethanolamine, and DMF: dimethylformamide.
The crude linear peptides were oxidized to the desired monomeric monocyclic peptides in the presence of 10% dimethylsulfoxide (DMSO) in 0.1M NH 4 HCO 3 solution at pH 8.0 as described in Tam et al., J. Am. Chem. Soc. 113: 6657–6662, 1991. The cyclization reactions were monitored by reverse-phase high performance liquid chromatography (RP-HPLC) over a C18 column (Rocket Platinum EPS, Alltech, NSW) using appropriate linear gradients of acetonitrile in 0.1% TFA.
The monomeric monocyclic peptides were purified by RP-HPLC (Econosil C18, Alltech, NSW), and the identity of each peptide confirmed by electrospray mass spectrometry. These peptides are listed in the following Table 1.
TABLE 1
Sequence and predicted and actual molecular masses
(determined by mass spectrometry) of peptides synthesized
mass
mass
num-
actual
ber
sequence
predicted
[M + H]
1
1358.52
1360
2
908.02
909.5
3
1116.37
1117.6
4
2793.18
2793.9
5
3566.09
3567.1
6
2019.6
2020.8
7
905.41
907
8
719.32
720.5
9
632.28
633.6
10
1014.5
1015.4
11
927.47
928.3
Example 4
Inhibition of VEGF-D-induced VEGFR-2-mediated Cell Survival by Monomeric Monocyclic Mimetics of Receptor Binding Loops of VEGF-D
The purified monomeric monocyclic peptides 1, 2 and 3 were tested for the ability to interfere with the activity of recombinant VEGF-DΔNΔC mediated by mouse VEGFR-2 (also known as Flk 1 and NyK) using the bioassay described in Achen et al., Proc. Natl. Acad. Sci. USA 95: 548–553, 1998. The bioassay is also described in Example 7 of International patent application No. PCT/US95/14696 (WO 98/07832). This assay involves the use of Ba/F3 pre-B cells which have been transfected with a plasmid construct encoding a chimeric receptor consisting of the extracellular domain of VEGFR-2 and the cytoplasmic domain of erythropoietin receptor (EpoR) (Ba/F3-NYK-EpoR cells). These cells are routinely passaged in interleukin-3 (IL-3) and will die in the absence of IL-3. However, if signaling is induced from the cytoplasmic domain of the chimeric receptor, these cells survive and proliferate in the absence of IL-3. Such signaling is induced by ligands which bind to the VEGFR-2 extracellular domain of the chimeric receptor. Therefore binding of VEGF-DΔNΔC to the VEGFR-2 extracellular domain causes the cells to survive and proliferate in the absence of IL-3. Addition of monomeric monocyclic peptides which interfere with the binding of such ligands to the extracellular domain or with the activation of the cytoplasmic domain will cause cell death in the absence of IL-3. Parental Ba/F3 cells which lack the chimeric receptor are not induced by VEGF-DΔNΔC to proliferate in the absence of IL-3, indicating that the responses of the Ba/F3-NYK-EpoR cells to these ligands are totally dependent on the chimeric receptor.
Cells were cultured in the presence of IL-3 until required, then washed three times in phosphate buffered saline (PBS), resuspended in IL-3-free cell culture medium (Dulbecco's Modified Eagle's Medium supplemented with fetal calf serum (10%), L-glutamine (1%), geneticin (1 mg/ml), streptomycin (100 μg/ml) and penicillin (60 μg/ml)) and replated in 72-well culture plates (Nunc, Denmark) at a density of approximately 1000 cells/well. Monomeric monocyclic peptides 1, 2 and 3 were added to culture wells to give final concentrations of 10 −10 to 10 −5 M. After incubation for 1 hour at 37° C. in 10% CO 2 , recombinant VEGF-DΔNΔC (500 ng/ml) was added to the peptide-containing wells at a concentration to produce near-maximal survival. Positive control cultures contained growth factor supernatant alone and negative control cultures contained neither peptide nor growth factor. Cells were grown in culture for 48 hours, after which time a solution of 3-(3,4-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) (500 μg/ml) was added to the cultures, which were incubated for a further 30 minutes. MTT is converted to a blue formazan product by mitochondria, staining living cells blue. Surviving blue cells were counted under a microscope with inverted optics (100×magnification) and cell survival expressed as a percentage of survival in positive control (growth factor only) wells.
Data was analyzed by one way analysis of variance (ANOVA), with a Bonferroni multiple comparisons test carried out post-hoc to test for differences between individual cultures of peptide+ growth factor (treatment) with growth factor alone (positive control).
As shown in FIGS. 3 a–c , respectively, peptides 1, 2 and 3 were found to inhibit VEGF-D-induced VEGFR-2-mediated cell survival. Although none of the peptides completely inhibited the action of VEGF-DΔNΔC in these assays, they each showed appreciable inhibition at the highest concentration used, 10 −4 M (peptide 1: 79±5%; peptide 2: 86±3%; peptide 3: 74±3%). Cell survival was normalized such that survival in negative controls (N) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P) was set to 100% (typically 300–400 cells/well).
Example 5
Inhibition of VEGF-induced VEGFR-2-mediated Cell Survival by Monomeric Monocyclic Mimetics of Receptor Binding Loops of VEGF-D
Next the monomeric monocyclic peptides 1, 2 and 3 each were assessed for their ability to inhibit the VEGF-induced VEGFR-2-mediated cell survival in the cell-based bioassay described in Example 4. The assay was carried out as described in Example 4, except that the peptides were assayed in competition with recombinant mouse VEGF 164 (10 ng/ml).
As shown in FIGS. 4 a–b , respectively, monomeric, monocyclic peptides 1 and 2, were found to inhibit VEGF-induced VEGFR-2-mediated cell survival in a concentration dependent manner. In these experiments, the maximal inhibitory effect (observed at 10 −4 M) of peptides 1 (56±2%) and 2 (56±3%) was less than that observed for the same peptides against VEGF-D. In comparison, the monomeric monocyclic peptide 3 did not inhibit VEGF-induced VEGFR-2-mediated cell survival at any of the concentrations tested ( FIG. 4 c ). This latter result was surprising, in that peptide 3 was an effective inhibitor of VEGF-D-mediated cell survival (see Example 4 above). Cell survival was normalized as above such that survival in negative controls (N, containing neither VEGF nor peptide) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P, containing VEGF alone) was set to 100% (typically 300–400 cells/well).
Example 6
Specificity of Inhibition of VEGFR-2 Ligand Mediated Cell Survival by Monomeric Monocyclic Mimetics of Receptor Binding Loops of VEGF-D
To determine the specificity of the monomeric monocyclic peptides 1, 2 and 3, the peptides were assayed in competition with IL-3. The assay was carried out as described in Example 4, except that the peptides were assayed in competition with recombinant IL-3 (10 ng/ml). As shown in FIGS. 5 a – 5 c , respectively, neither peptide 1, 2 nor 3 was found to inhibit the action of IL-3 in this assay. Cell survival was again normalized such that survival in negative controls (N, containing neither IL-3 nor peptide) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P, containing IL-3 alone) was set to 100% (typically 300–400 cells/well).
Example 7
Molecular Design of Bicyclic Dimeric Mimetics of Receptor Binding Loops of VEGF-D
Next bicyclic dimeric mimetics were constructed. To aid in the design of such peptides, the same model of VEGF-D was used. Examination of this model showed that loops 1 and 2 are juxtaposed, one loop being contributed by one VEGF-D monomer, the other coming from the other monomer ( FIG. 1 ). As indicated in FIG. 6 , these loops are predicted to be connected to one another by an intermolecular disulfide bond between Cys 136 of loop 1 and Cys 145 of loop 2. Dotted lines show the approximate positions of the cysteine residues used to constrain the monocyclic monomeric mimetics of loop 1 and loop 2 (peptides 1 and 2 respectively). Using this information, the heterodimeric, bicyclic peptide 5 was designed (Table 1).
Example 8
Synthesis of Bicyclic Dimeric Mimetics of Receptor Binding Loops of VEGF-D
As illustrated in FIG. 7 , the heterodimeric bicyclic peptide 5 was synthesized using a mixed cysteine-protection strategy. Briefly, linear L1 and L2 peptides—suitably lengthened to allow formation of a dimerizing linkage analogous to that predicted to exist in native VEGF-D—were assembled from fluorenyl methoxycarbonyl (Fmoc) amino acids and cleaved from the resin as described in Example 3, using TFA-labile Trt protection on the Cys residues to be cyclized, and the TFA-stable acetamidomethyl (Acm) protecting group on the Cys residues to be used to form the dimerization linkage. The linear L1 and L2 peptides were cyclized via their free Cys residues to give the partially-(Acm-) protected monomeric monocyclic peptides. Following their purification by RP-HPLC as described in Example 3, the two partially-protected monomeric monocyclic peptides were dimerized by stirring an equimolar solution of the peptides in the presence of iodine. These conditions should both remove the Acm protecting group and oxidize the resultant free Cys residues to the disulfide-linked cysteine. As shown in FIG. 7 , this same approach yielded the homodimers 4 and 6.
The dimerization reaction was monitored by RP-HPLC, as shown in FIG. 8 . After three hours, all of one of the starting compounds (the Acm-protected monomeric monocyclic L1 peptide) had reacted, although there was still some of the other starting compound (the Acm-protected monomeric monocyclic L2 peptide). Also, three new peaks could be detected. Mass spectrometry analysis of these peaks showed them to have molecular weights consistent with fully deprotected monomeric monocyclic peptide L1, the bicyclic homodimer 4 as well as the bicyclic heterodimer 5. No appreciable amounts of either the fully deprotected monomeric monocyclic peptide L2 or the bicyclic homodimer 6 could be detected, indicating that the iodine-mediated removal of Acm from the L2 peptide was significantly slower than the removal of Acm from the L1 peptide. The bicyclic heterodimer 5 and the bicyclic homodimer 4 were purified by RP-HPLC as described in Example 3.
The bicyclic homodimer 6 was synthesized by treating a solution of the partially-protected monomeric monocyclic peptide L2 with iodine. The desired compound was purified by RP-HPLC as described in Example 3.
Example 9
Inhibition of VEGF-D-induced VEGFR-2-mediated Cell Survival by Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D
The heterodimeric bicyclic peptide 5 and the homodimeric bicyclic peptides 4 and 6 each were assayed in competition with VEGF-DΔNΔC in the cell-based bioassay described in Example 4. As shown in FIGS. 9 a–c , all three peptides caused a concentration dependent inhibition of VEGF-D-mediated cell survival to a greater extent than any of the monomeric monoyclic peptides 1, 2 or 3 [maximum inhibition (at 10 −4 M) peptide 4: 100% ( FIG. 9 a ); peptide 5: 84±4% ( FIG. 9 b ); peptide 6: 87±4% ( FIG. 9 c )]. Cell survival was normalized such that survival in negative controls (N, containing neither VEGF-D nor peptide) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P, containing VEGF-D alone) was set to 100% (typically 300–400 cells/well).
Example 10
Inhibition of VEGF-induced VEGFR-2-mediated Cell Survival by Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D
Next, the heterodimeric bicyclic peptide 5 and the homodimeric bicyclic peptides 4 and 6 each were subsequently assayed in competition with VEGF in the cell-based bioassay described in Example 4. As shown in Figures 10 a–c , all three peptides caused a concentration dependent inhibition of VEGF mediated cell survival again to a greater extent than any of the monomeric monoyclic peptides 1, 2 or 3 [maximum inhibition (at 10 −4 M) peptide 4: 90±2% ( FIG. 10 a ); peptide 5: 87±3% ( FIG. 10 b ); peptide 6: 61±10% ( FIG. 10 c )]. Cell survival was normalized such that survival in negative controls (N, containing neither VEGF nor peptide) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P, containing VEGF alone) was set to 100% (typically 300–400 cells/well).
Example 11
Specificity of Inhibition of VEGFR-2 Ligand Mediated Cell Survival by Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D
When assayed in competition with IL-3, the heterodimeric bicyclic peptide 5 caused a significant reduction in cell number, of 98±2%, at 10 −4 M ( FIG. 11 b ). In contrast neither of the homodimeric bicyclic peptides 4 or 6 caused a significant change in cell number, compared to the IL-3 only controls, as shown in FIGS. 11 a and 11 c , respectively. Cell survival is normalized such that survival in negative controls (N, containing neither IL-3 nor peptide) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P, containing IL-3 alone) was set to 100% (typically 300–400 cells/well).
Example 12
Inhibition of VEGF-D-induced VEGFR-3-mediated Cell Survival by Monomeric Monocyclic Mimetics and Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D
The purified monomeric monocyclic peptides 1, 2 and 3 and the dimeric bicyclic peptides 4, 5 and 6 were tested for the ability to interfere with the activity of recombinant VEGF-DΔNΔC mediated by mouse VEGFR-3 using a modification of the bioassay described in Achen et al., Eur. J. Biochem., 267: 2505–2515, 2000. This assay involves the use of Ba/F3 pre-B cells which have been transfected with a plasmid construct encoding a chimeric receptor consisting of the extracellular domain of VEGFR-3 and the cytoplasmic domain of erythropoietin receptor(EpoR). These cells are routinely passaged in the presence of interleukin-3 (IL-3 ) and will die in the absence of IL-3. However, if signaling is induced from the cytoplasmic domain of the chimeric receptor, these cells survive and proliferate in the absence of IL-3. Such signaling is induced by ligands which bind to the VEGFR-3 extracellular domain of the chimeric receptor. Therefore binding of VEGF-D to the VEGFR-3 extracellular domain causes the cells to survive and proliferate in the absence of IL-3. Addition of peptides which interfere with the binding of such ligands to the extracellular domain or with the activation of the cytoplasmic domain will cause cell death in the absence of IL-3. Parental Ba/F3 cells which lack the chimeric receptor are not induced by ligands for VEGFR-3 to proliferate in the absence of IL-3, indicating that the responses of the transfected cells to these ligands are totally dependent on the chimeric receptor.
Cells were cultured in the presence of IL-3 until required, then washed three times in phosphate buffered saline (PBS), resuspended in IL-3-free cell culture medium (Dulbecco's Modified Eagle's Medium supplemented with fetal calf serum (10%), L-glutamine (1%), geneticin (1 mg/ml), streptomycin (100 μg/ml) and penicillin (60 μg/ml)) and replated in 72-well culture plates (Nunc, Denmark) at a density of approximately 1000 cells/well. Monomeric monocyclic peptides 1, 2 and 3 and the dimeric bicyclic peptides 4, 5 and 6 were added to culture wells to give final concentrations of 10 −10 to 10 −5 M. After incubation for 1 hour at 37° C. in 10% CO 2 , recombinant VEGF-DΔNΔC (500 ng/ml) was added to the peptide-containing wells at a concentration to produce near-maximal survival. Positive control cultures contained VEGF-DΔNΔC alone and negative control cultures contained neither peptide nor growth factor. Cells were grown in culture for 48 hours, after which time a solution of 3-(3,4-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT 500 μg/ml) was added to the cultures, which were incubated for a further 30 minutes. MTT is converted to a blue formazan product by mitochondria, staining living cells blue. Surviving blue cells were counted under a microscope with inverted optics (100×magnification) and cell survival expressed as a percentage of survival in positive control (growth factor only) wells. Cell survival was normalized such that survival in negative controls (N) was set to 0 (typically no viable cells were seen in negative controls), while survival in positive controls (P) was set to 100% (typically 300–400 cells/well). Data was obtained in triplicate from three separate experiments.
As shown in FIGS. 12 a–c , respectively, the monomeric monocyclic peptides 1, 2 and 3 were found to inhibit VEGF-D-induced VEGFR-3-mediated cell survival. Although no peptide completely inhibited survival, all three peptides were effective inhibitors at the highest concentration used, 10 −4 M (peptide 1: 73±9%; peptide 2: 88±10%; peptide 3: 61±8%). Similarly, the dimeric bicyclic peptides 4, 5 and 6 ( FIGS. 13 a–c , respectively) also inhibited VEGF-D-induced VEGFR-3-mediated cell survival (inhibition at 10 −4 M: peptide 4: 52±9%; peptide 5: 69±16%; peptide 6: 44±7%). These results differ somewhat from those obtained with the inhibition of VEGF-D-induced VEGFR-2-mediated cell survival described in Examples 4 and 9 above, in that none of the dimeric bicyclic peptides appear to be more effective inhibitors than the monomeric monocyclic peptides.
Example 13
Inhibition of VEGF-C-induced VEGFR-2-mediated Cell Survival by Monomeric Monocyclic Mimetics and Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D
The purified monomeric monocyclic peptides 1, 2 and 3 and the dimeric bicyclic peptides 4, 5 and 6 were tested for the ability to interfere with the activity of recombinant VEGF-C mediated by mouse VEGFR-2. Cells were passaged and the assay carried out in an analogous manner to that described in Example 4 above, except that 1 hour after the addition of the monomeric monocyclic peptides 1, 2 and 3 and the dimeric bicyclic peptides 4, 5 and 6 to the respective culture wells, recombinant VEGF-CΔNΔC (the VEGF homology domain of VEGF-C, described previously in Joukov et al., EMBO J. 16: 3898–3 1911, 1997) was added, at a concentration to produce near-maximal survival (50 ng/ml).
As shown in FIGS. 14 a–c , respectively, the monomeric monocyclic peptides 1, 2 and 3 each were found to inhibit VEGF-C-induced VEGFR-2-mediated cell survival. The data differ somewhat from that obtained against VEGF-D-induced VEGFR-3-mediated cell survival in Example 12 above, in that the most effective inhibitor is peptide 3 (inhibition at 10 −4 M: peptide 1: 48±10%; peptide 2: 67±10%; peptide 3: 93±4%). The dimeric bicyclic peptides 4, 5 and 6 ( FIGS. 15 a–c , respectively) also inhibited VEGF-C-induced VEGFR-2-mediated cell survival, with both peptides 4 and 5 giving near complete inhibition at 10 −4 M (peptide 4: 94±2%; peptide 5: 99±1%; peptide 6: 83±6%).
Example 14
Inhibition of VEGF-C-induced VEGFR-3-mediated Cell Survival by Monomeric Monocyclic Mimetics and Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D
The purified monomeric monocyclic peptides 1, 2 and 3 and the dimeric bicyclic peptides 4, 5 and 6 each were tested for the ability to interfere with the activity of recombinant VEGF-C mediated by mouse VEGFR-3, using the VEGFR-3 bioassay described in Example 12 above. The assay was carried out in an analogous manner to that described in Example 12, except that 1 hour after the addition of the monomeric monocyclic peptides 1, 2 and 3 and the dimeric bicyclic peptides 4, 5 and 6 to culture wells, recombinant VEGF-CΔNΔC was added, at a concentration to produce near-maximal survival(3 ng/ml).
As shown in FIGS. 16 a–c , respectively, the monomeric monocyclic peptides 1, 2 and 3 each were found to inhibit VEGF-C-induced VEGFR-3-mediated cell survival. Like the data obtained for VEGF-C-induced VEGFR-2-mediated cell survival described in Example 13 above, the most effective inhibitor was peptide 3 (maximal inhibition of 86±6% at 10 −5 M compared to peptide 1: 46±12% at 10 −4 M; peptide 2: 72±14% at 10 −4 M) . All three dimeric bicyclic peptides 4, 5 and 6 ( FIGS. 17 a–c , respectively) were effective inhibitors of VEGF-C-induced VEGFR-3-mediated cell survival (inhibition at 10 −4 M: peptide 4: 100═0%; peptide 5: 97±2%; peptide 6: 95±2%).
Example 15
Molecular Design of N- and C-terminally Shortened Analogs of Monomeric Monocyclic Peptide 3
To evaluate the importance of individual amino acid residues and the minimum cycle size required for inhibitory activity of the monomeric monocyclic peptide 3, a series of N- and C-terminally shortened peptides 7, 8 and 9 (Table 1) were designed. These monomeric monocyclic peptides, which are shortened by two residues (peptide 7). four residues (peptide 8) and five residues (peptide 9) compared to peptide 3, were designed from the model of VEGF-D in a manner analogous to that used to design the monomeric moncyclic peptides 1, 2 and 3, described in Example 2.
Example 16
Synthesis of N- and C-terminally Shortened Analogs of Monomeric Monocyclic Peptide 3
The monomeric monocyclic peptides 7–9 were synthesised from Fmoc amino acids, purified by RP-HPLC and characterized by electrospray mass spectrometry as described in Example 3.
Example 17
Inhibition of VEGF, VEGF-C and VEGF-D-induced VEGFR-2-mediated cell Survival by N- and C-terminally Shortened Analogs of Monomeric Monocyclic Peptide 3
The monomeric monocyclic peptide 7 was assayed in competition with VEGF, VEGF-CΔNΔC and VEGF-DΔNΔC in the VEGFR-2 bioassay described in Example 4. Like the parent monomeric monocyclic peptide 3, peptide 7 did not inhibit the biological activity of VEGF at the concentrations tested ( FIG. 18 a ) However, in contrast to the parent peptide 3 , the absence of the N- and C-terminally derived Ile and Pro residues (peptide 7) also abolished the inhibitory activity against VEGF-C and VEGF-D through VEGFR-2 ( FIGS. 19 a and b ) . This result suggests that these two residues are either important themselves in binding to VEGFR-2 and thus preventing VEGF-C and VEGF-D from interacting with this receptor, or that they play a role in presenting adjacent residues in the loop 3-derived peptides for receptor binding. The other N- and C-terminally shortened peptide 3 analogs (peptides 8 and 9) were also without inhibitory activity over the concentration range examined when assayed in competition with VEGF in the VEGFR-2 bioassay ( FIGS. 18 b and c ).
Example 18
Inhibition of VEGF-C and VEGF-D-induced VEGFR-3-mediated Cell Survival by N- and C-terminally Shortened Analogs of Monomeric Monocylic Peptide 3
The monomeric monocyclic peptides 7 and 9 were subsequently assayed in competition with VEGF-CΔNΔC and VEGF-DΔNΔC in the VEGFR-3 bioassay described in Example 12. Neither peptide 7 nor 9 exhibited appreciable inhibition of either VEGF-C or VEGF-D activity through VEGFR-3 over the concentration range tested ( FIGS. 20 and 21 ), similar to the situation seen with peptide 7 in the VEGFR-2 bioassay.
Example 19
Specificity of Inhibition of N- and C-terminally Shortened Analogs of Monomeric Monocyclic Peptide 3
The monomeric monocyclic peptides 7–9 were assayed in competition with IL-3 in the VEGFR-2 bioassay as described in Example 6. None of the N- and C-terminally truncated peptides 7–9 caused a significant reduction in cell number of cultures grown in the presence of IL-3 ( FIG. 22 ).
Example 20
Molecular Design of Internally Shortened Analogs of Monomeric Monocyclic Peptide 3
Because the tested analogs of monomeric monocyclic peptide 3 lacking N- and C-terminal residues were found to be devoid of inhibitory activity at either VEGFR-2 or VEGFR-3, peptides were designed in which amino acids were removed internally from the loop. Two such monomeric monocyclic peptides were designed: peptide 1 0 , lacking an internal Thr, and peptide 1 1 , in which Thr-Ser was been removed (Table 1).
Example 21
Synthesis of Internally Shortened Analogs of Monomeric Monocyclic Peptide 3
The monomeric monocyclic peptides 10 and 11 were synthesised from Fmoc amino acids, purified by RP-HPLC and characterized by electrospray mass spectrometry as described in Example 3.
Example 22
Inhibition of VEGF-induced VEGFR-2-mediated Cell Survival by Internally Shortened Analogs of Monomeric Monocyclic Peptide 3
When assayed in competition with VEGF in the VEGFR-2 bioassay described in Example 4, neither of the monomeric monocylic peptides 10 nor 11 caused appreciable inhibition of VEGF-mediated cell survival over the concentration range tested ( FIG. 23 ).
Example 23
Inhibition of VEGF-C-induced VEGFR-3-mediated Cell Survival by Internally Shortened Analogs of Monomeric Monocyclic Peptide 3
The internally shortened peptides 10 and 11 were subsequently assayed in competition with VEGF-CΔNΔC in the VEGFR-3 bioassay described in Example 12. Unlike the N- and C-terminally shortened counterparts, the internally shortened peptides retained some inhibitory activity for VEGF-C (peptide 10: 57±11% inhibition at 10 −4 M, FIG. 24 a ; peptide 11: 33±6% inhibition at 10 −4 M, FIG. 24 b ). The data suggest both that the residues absent from these sequences are not absolutely required for inhibition of VEGF-C-mediated survival through VEGFR-3, and that the resultant internally shortened peptides are still able to present at least some of the residues required for receptor binding in an appropriate conformation.
Example 24
Specificity of Inhibition of Internally Shortened Analogs of Monomeric Monocyclic Peptide 3
The internally shortened peptides 10 and 11 were assayed in competition with IL-3 in the VEGFR-2 bioassay as described in Example 6. Neither peptide 10 or 11 caused a significant reduction of cell number of cultures grown in the presence of IL-3 ( FIG. 25 ). The data support the hypothesis that the inhibitory activity of these two peptide is due to a specific binding to VEGF receptors, and is not the result of non-specific inhibition of cell growth and survival.
Example 25
Synthesis of Monomeric Monocyclic Mimetics of Receptor Binding Loops of VEGF-D with Conservative Amino Acid Substitutions
Synthetic peptides are synthesized based on peptides 1, 2 and 3 with conservative amino acid substitutions and cyclized as described in Example 3. Peptide 12 corresponds to peptide 1 except that serine in position 3 is replaced by threonine. Peptide 13 corresponds to peptide 1 except that serine in position 8 is replaced by threonine and threonine in position 9 is replaced by serine. Peptide 14 corresponds to peptide 1 except that glutamic acid in position 4 is replaced by asparagine, leucine in position 5 is replaced by valine and phenylalanine in position 12 is replaced by tryptophan. Peptide 15 corresponds to peptide 1 except that leucine in position 7 is replaced by arginine, and threonine in position 11 is replaced by serine. Peptide 16 corresponds to peptide 2 except glutamic acid in position 3 is replaced by asparagine, and isoleucine in position 7 is replaced by leucine. Peptide 17 corresponds to peptide 2 except that serine in position 5 is replaced by threonine. Peptide 18 corresponds to peptide 2 except that glutamic acid in position 4 is replaced by asparagine, and leucine in position 6 is replaced by phenylalanine. Peptide 19 corresponds to peptide 2 except that leucine in position 6 and isoleucine in position 7 are each replaced by valine. Peptide 20 corresponds to peptide 3 except that isoleucine in position 2 is replaced by leucine. Peptide 21 corresponds to peptide 3 except that serine in position 3 is replaced by threonine, valine in position 4 is replaced by isoleucine, and valine in position 9 is replaced by leucine. Peptide 22 corresponds to peptide 3 except that valine in position 4 is replaced by leucine, leucine in position 6 is replaced by isoleucine, and threonine in position 7 is replaced by serine. Peptide 23 corresponds to peptide 3 except that isoleucine in position 2 is replaced by valine, and serine in position 8 is replaced by threonine. The sequences of the synthetic cyclic peptides are shown in the following Table 2.
TABLE 2
Synthetic peptides based on exposed loop fragments of
VEGF-D with conservative amino acid substitutions
peptide
number
sequence
sequence id no.
12
(SEQ ID NO:15)
13
(SEQ ID NO:16)
14
(SEQ ID NO:17)
15
(SEQ ID NO:18)
16
(SEQ ID NO:19)
17
(SEQ ID NO:20)
18
(SEQ ID NO:21)
19
(SEQ ID NO:22)
20
(SEQ ID NO:23)
21
(SEQ ID NO:24)
22
(SEQ ID NO:25)
23
(SEQ ID NO:26)
Example 26
Synthesis of Dimeric Bicyclic Mimetics of Receptor Binding Loops of VEGF-D with Conservative Amino Acid Substitutions
Synthetic peptides are synthesized based on peptides 4 and 5 with conservative amino acid substitutions, cyclized and dimerized as described in Example 8. Peptide 24 corresponds to peptide 4 except that serine in position 3 of SEQ ID NO 27 is replaced by threonine. Peptide 25 corresponds to peptide 4 except that serine in position 8 of SEQ ID NO 28 is replaced by threonine, and threonine in position 9 of SEQ ID NO 28 is replaced by serine. Peptide 26 corresponds to peptide 4 except that glutamic acid in position 4 of SEQ ID NO 29 is replaced by asparagine, leucine in position 5 of SEQ ID NO 29 is replaced by valine and phenylalanine in position 12 of SEQ ID NO 29 is replaced by tryptophan. Peptide 27 corresponds to peptide 4 except that lysine in position 7 of SEQ ID NO 30 is replaced by arginine, and threonine in position 11 of SEQ ID NO 30 is replaced by serine. Peptide 28 corresponds to peptide 5 except that phenylalanine in position 12 of SEQ ID NO 31 is replaced by tyrosine. Peptide 29 corresponds to peptide 5 except that lysine in position 7 of SEQ ID NO 32 is replaced by arginine, and threonine in position 11 of SEQ ID NO 32 is replaced by serine. Peptide 30 corresponds to peptide 5 except that glutamic acid in position 4 of SEQ ID NO 33 is replaced by aspartic acid, and isoleucine in position 8 of SEQ ID NO 33 is replaced by leucine. Peptide 31 corresponds to peptide 5 except that serine in position 6 of SEQ ID NO 34 is replaced by threonine, and leucine in position 7 of SEQ ID NO 34 is replaced by valine. The sequences of the dimerized, bicyclic synthetic peptides are shown in the following Table 3.
TABLE 3
Synthetic peptides based on exposed loop fragments of
VEGF-D with conservative amino acid substitutions
peptide
number
sequence and sequence id no.
24
25
26
27
28
29
30
31
The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations falling within the scope of the appended claims and equivalents thereof.
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Monomeric monocyclic peptide inhibitors and dimeric bicyclic peptide inhibitors based on exposed loop fragments of a growth factor protein, such as loop 1, 2 or 3 of VEGF-D, and methods of making them are described as well as pharmaceutical compositions containing them and methods utilizing them.
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FIELD OF THE INVENTION
The present invention relates to telephone signaling systems in general, and more particularly to methods and apparatus for controlling telephone rings.
BACKGROUND OF THE INVENTION
It is curtly not possible for a telephone caller to know prior to placing a telephone call to another party the number of rings and the delay between rings that will occur at the called party's telephone. This is due mainly to the differences between telephone systems, even within a single country or area code. Furthermore, different providers of PABX services utilize different ring generators, and those PABXs that have computer interfaces often take different routes to the various destination computers, causing rings and delays at a particular client computer to vary from those of another client computer, even within the same PABX system.
SUMMARY OF THE INVENTION
The present invention seeks to provide an automatic tuning process whereby a telephone caller may know prior to placing a telephone call to another party the number of rings and the delay between rings that will occur at the called party's telephone. The invention is preferably implemented using a computer, such as a personal computer or a wireless computer device such as a World-Wide-Web enabled device, that is adapted to place a telephone call via a land-based or wireless telephone network. The called party's computer or wireless device then provides ring and delay information to the calling computer via a computer network. The ring and delay information may then be used by the calling computer to cause a predetermined number of telephone ring signals and ring separation delays to occur at a called computer or web-enabled wireless device in order to convey information thereby.
There is thus provided in accordance with a preferred embodiment of the present invention a method for determining the time required for a server to effect a telephone ring signal at a client computer, the method including tracking elapsed time concurrently at the server and the client computer, initiating a telephone call from the server to the client computer after a specified time period has elapsed, detecting at least one telephone ring signal at the client computer, recording the time at which the telephone ring signal is detected at the client computer, and transmitting the recorded time to the server.
Further in accordance with a preferred embodiment of the present invention the method further includes transmitting an indication of the specified time period to the client computer.
Still further in accordance with a preferred embodiment of the present invention any of the transmitting steps includes transmitting via a network.
Additionally in accordance with a preferred embodiment of the present invention the method further includes maintaining the call for a predetermined length of time sufficient for three ring signals to be detected at the client computer.
Moreover in accordance with a preferred embodiment of the present invention the method further includes discontinuing the call subsequent to the detecting step.
There is also provided in accordance with a preferred embodiment of the present invention a method for conveying information to a computer, the method including notifying the computer of at least one ring-and-delay combination and the information that the combination represents, initiating a telephone call to the computer, effecting the ring-and-delay combination at the computer via the telephone call, and detecting the ring-and-delay combination at the computer, thereby conveying the information to the computer.
Further in accordance with a preferred embodiment of the present invention the method further includes varying the ring-and-delay combination in accordance with an algorithm known in advance to the computer.
There is additionally in accordance with a preferred embodiment of the present invention a method for conveying information to a computer, the method including determining the time required for a server to effect a telephone ring signal at the computer by tracking elapsed time concurrently at the server and the computer, initiating a telephone call from the server to the computer after a specified time period has elapsed, detecting at least one telephone ring signal at the computer, recording the time at which the telephone ring signal is detected at the computer, and transmitting the recorded time to the server, notifying the computer of at least one ring-and-delay combination and the information that the combination represents, initiating a telephone call to the computer, effecting the ring-and-delay combination using the recorded time at the computer via the telephone call, and detecting the ring-and-delay combination at the computer, thereby conveying the information to the computer.
It is appreciated throughout the specification and claims that the term “automatic tuning process” refers to a procedure for determining the time required for a computer server to effect one or more telephone ring signals at a client computer, that the term “signaling operation” refers to a procedure for causing a predetermined number of telephone ring signals and ring separation delays to occur at a client computer, that the term “computes” refers to any device incorporating a central processing unit, such as, but not limited to, a personal computer, a notebook computer, and a cellular telephone, and that the term “network” refers to a wired or wireless computer network or other telecommunications network capable of conveying electronic transmissions between computers.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the appended drawings, in which:
FIG. 1 is a simplified conceptual illustration of a system for controlling telephone rings, constructed and operative in accordance with a preferred embodiment of the present invention;
FIG. 2 is a simplified flowchart illustration of an exemplary automatic tuning process of the system of FIG. 1, operative in accordance with a preferred embodiment of the present invention; and
FIG. 3 is a simplified flowchart illustration of an exemplary signaling operation of the system of FIG. 1, operative in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is now made to FIG. 1, which is a simplified conceptual illustration of a system for controlling telephone rings, constructed and operative in accordance with a preferred embodiment of the present invention. In the system of FIG. 1 a client computer 10 , which may be any known computer or web-enabled wireless device, is shown in telephonic communication with a network 12 , typically the Internet, using any conventional means. Client 10 is adapted to send transmissions to a server 14 , which may be any known server computer, via network 12 using any suitable network communications protocol, and likewise to receive transmissions from server 14 . Server 14 is adapted to place a telephone call via a land-based or wireless telephone network 16 using dialing apparatus 18 to client 10 in response to receiving a transmission from client 10 . Dialing apparatus 18 may be any known dialing means controllable by a server, such as a standard modem. Client 10 is adapted to detect the call using call detection apparatus 20 . Detection apparatus 20 may be any known call detection means for interfacing with client 10 , and is adapted to identify telephone rings and provide notifications of ring events to client 10 .
Reference is now made to FIG. 2, which is a simplified flowchart illusion of an exemplary automatic tuning process of the system of FIG. 1 operative in accordance with a preferred embodiment of the present invention. In the method of FIG. 2 client 10 establishes a telephonic connection to network 12 and sends a transmission via network 12 to server 14 (step 100 ). The transmission may include information identifying client 10 , including client 10 's network address, or else client 10 's network address may simply be included in the transmission header in accordance with standard network transmission protocols. Once server 14 identifies client 10 from the transmission, server 14 sends a transmission via network 12 to client 10 indicating that an automatic tuning process is about to commence (step 110 ). The transmission from server 14 may indicate to client 10 that the automatic tuning process will begin after a specified period of time elapses from the time of receipt of the transmission from server 14 by client 10 . Alteratively, this period of time may be predefined in advance and known to both server 14 and client 10 , and thus need not be conveyed by transmission. Client 10 then preferably acknowledges receipt of the transmission from server 14 and disconnects from network 12 (step 120 ). Server 14 begins tacking the elapsed time of the automatic tuning process from the time it sent its transmission to client 10 , or alternatively from the time server 14 received client 10 's acknowledgement (step 130 ). Client 10 likewise begins tracking the elapsed time of the automatic tuning process from the time it received server 14 's transmission, or alternatively from the time client 10 sent its acknowledgement of receipt of server 14 's transmission (step 140 ). Typically, both client 10 and server 14 track elapsed time by referring to an internal system clock in accordance with conventional techniques.
Once the specified period of time has elapsed, server 14 initiates a telephone call to client 10 via telephone network 16 using dialing apparatus 18 (step 150 ). Upon receipt of the call at call detection apparatus 20 , detection apparatus 20 indicates to client 10 that a call has been received. Preferably, detection apparatus 20 notifies client 10 of events relating to the call using known telephony application programming interface (TAPI) protocols, with detection apparatus 20 sending client 10 an event message each time a ring signal is detected (step 160 ). Client 10 records the time of each ring signal event in terms of the current elapsed time from the start of the automatic tug process (step 170 ). Server 14 maintains the call for a predetermined length of time, preferably sufficient for three rings to be detected by detection apparatus 20 (step 180 ). Server 14 then instructs dialing apparatus 18 to discontinue the call to client 10 (step 190 ).
After waiting a predefined period of time in which no rings are detected, client 10 reestablishes a telephonic connection to network 12 and transmits to server 14 via network 12 the recorded time of one or more of the ring signal events in terms of the elapsed time from the start of the automatic tuning process (step 200 ). Typically, client 10 only transmits the recorded times of the first two ring events it encounters. Thus, for example, if t 0 is the time at which the automatic tuning process is to begin, the first ring event t 1 might be reported as t 0 +2 seconds, while the second ring event t 2 might be reported as t 0 +6 seconds, and the third at t 0 +10 seconds. Alternatively, each ring event may be reported in terms of a time offset from the immediately-preceding ring event (e.g., t 1 t 0 +2 seconds, t 2 =t 1 +4 seconds, etc.). In this manner, server 14 may know that a telephone call placed to client 10 at a time to for a duration of t 0 +6 seconds will cause one complete ring to occur at client 10 , that a call of a duration <t 0 +10 seconds will cause a second complete ring to occur at client 10 , and that a ring cycle from the start of one ring until the start of the next ring is 4 seconds.
It is appreciated that the method of FIG. 2 may be implemented periodically in order to obtain updated tuning information, this in accordance with a predetermined schedule or at the initiative of either client 10 or server 14 .
Reference is now made to FIG. 3, which is a simplified flowchart illustration of an exemplary signaling operation of the system of FIG. 1, operative in accordance with a preferred embodiment of the present invention In the method of FIG. 3, server 14 uses ring signal timing data received from client 10 as part of an automatic tuning process to convey information to client 10 . The signaling operation begins with server 14 notifying client 10 , typically as part of a transmission via network 12 , of one or more ring-and-delay combinations and the information that each particular ring and delay combination represents (step 300 ). For example, server 14 might indicate to client 10 that two rings followed by a delay of 45 seconds followed by one ring indicates that an email message has arrived at server 14 that is addressed to client 10 . Thus, when server 14 wishes to signal client 10 , it initiates a telephone call to client 10 at time to and begins tracking the elapsed time (step 310 ). The two rings are then effected at client 10 at times t 0 +2 and t 0 +6 (step 320 ), with the call being terminated prior to t 0 +10 (step 330 ). Preferably, termination of a call should be sufficiently prior to the beginning of the next ring, such as by terminating the call at t 0 +(0.8=(ring cycle)) or at another faction of the ring cycle. A second telephone call is then initiated at t 0 +45−2 (since, in this example, a fist ring occurs two seconds after the initiation of the telephone call) (step 340 ) and terminated prior to t 0 +45+4 (step 350 ), thus completing the two-rings-delay-one-ring signaling operation.
It is appreciated that the various ring-and-delay combinations need not be fixed, but rather may vary in the number of rings, the length of the delays, and the combination of rings and delays. Thus, the 45 second delay in the preceding example may be extended to 50 seconds in the next signaling operation and still convey the same information. In a variation of the preceding example server 14 might simulate the initial two-ring telephone call using two one-ring telephone calls separated by a delay of a few seconds. The variations may be transmitted to client 10 by server 14 or may be applied in accordance with an algorithm known in advance to both client 10 and server 14 and dependant on factors such as the date and time of the telephone call or other known pseudo-randomization factors.
It is appreciated that one or more steps of any of the methods described herein may be omitted or implemented in a different order than that shown while not departing from the spirit and scope of the invention.
While the methods and apparatus disclosed herein may or may not have been described with reference to specific hardware or software, the methods and apparatus have been described in a manner sufficient to enable persons of ordinary skill in the art to readily adapt commercially available hardware and software as may be needed to reduce any of the embodiments of the present invention to practice without undue experimentation and using conventional techniques.
While the present invention has been described with reference to a few specific embodiments, the description is intended to be illustrative of the invention as a whole and is not to be construed as limiting the invention to the embodiments shown. It is appreciated that various modifications may occur to those skilled in the art that, while not specifically shown herein, are nevertheless within the true spirit and scope of the invention.
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A method for determining the time required for a server to effect a telephone ring signal at a client computer, the method including tracking elapsed time concurrently at the server and the client computer, initiating a telephone call from the sever to the client computer after a specified time period has elapsed, detecting at least one telephone ring signal at the client computer, recording the time at which the telephone ring signal is detected at the client computer, and transmitting the recorded time to the server.
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FIELD OF THE INVENTION
[0001] This invention relates to proppant sand slurry compositions and methods of making and using the same.
BACKGROUND OF THE INVENTION
[0002] Hydraulic fracturing operations are used routinely to increase oil and gas production. In a hydraulic fracturing process, a fracturing fluid is injected through a wellbore into a subterranean formation at a pressure sufficient to initiate a fracture to increase oil and gas production. Frequently, particulates, called proppants, are suspended in the fracturing fluid and transported into the fracture as a slurry. Proppants include sand, resin coated proppants, ceramic particles, glass spheres, bauxite (aluminum oxide), and the like. Among them, sand is by far the most commonly used proppant. Fracturing fluids in common use include various aqueous and hydrocarbon gels. Liquid carbon dioxide and nitrogen gas are also used in fracturing treatments. The most commonly used fracturing fluids are aqueous fluids containing cross-linked polymers to initiate fractures in the formation and effectively transport proppants into the fractures. At the last stage of a fracturing treatment, fracturing fluid is flowed back to surface and proppants are left in the fracture to prevent it from closing back after pressure is released. The proppant-filled fracture provides a high conductive channel that allows oil and/or gas to seep through to the wellbore more efficiently. The conductivity of the proppant pack plays a dominant role in increasing oil and gas production. However it is well known that polymer residues from polymer fracturing fluids greatly reduce the conductivity of the proppant-pack.
[0003] Besides normal sand, resin coated proppant is also commonly used in fracturing treatments, especially, to mitigate proppant flowback after a fracturing treatment. The outer surfaces of the resin-coated proppants have an adherent resin coating so that the proppant grains can be bonded to each other under suitable conditions forming a permeable barrier. The substrate materials for the resin-coated proppants include sand, glass beads and organic materials such as shells or seeds. The resins used include epoxy, urea aldehyde, phenol-aldehyde, furfural alcohol and furfural. The resin-coated proppants can be either pre-cured or can be cured by an overflush of a chemical binding agent, commonly known as activator, which often contains a surfactant. Different binding agents have been used. U.S. Pat. Nos. 3,492,147 and 3,935,339 disclose compositions and methods of coating solid particulates with different resins. The particulates which can be coated include sand, nut shells, glass beads, and aluminum pellets. The resins used include urea-aldehyde resins, phenol-aldehyde resins, epoxy resins, furfuryl alcohol resins, and polyester or alkyl resins. The resins can be in pure form or mixtures containing curing agents, coupling agents or other additives. To reduce the proppant flowback, the resin coated proppants are pumped into the near-wellbore formation in the last portion of the sand stage to form a permeable barrier.
[0004] The density of proppants is normally much greater than the density of water. The large density difference between proppants and water makes proppant settle quickly in water, even under high turbulence. Once settled, proppant is not easily lifted by the flow of the aqueous liquid in which it has settled.
[0005] Conventionally, to make a relatively stable slurry under static or/and dynamic conditions, proppant is commonly suspended in a viscoelastic liquid. In viscoelastic fluids, yield stress plays a dominant role in suspending proppants. Yield stress is the minimum shear stress required to initiate flow in a viscoelastic fluid. Basically, the viscosity of the fluid works to slow down the rate of proppant settling, while the yield stress helps to suspend the proppant. Under dynamic conditions, agitation or turbulence further help stabilize the slurry. Therefore, to make stable and cost-effective proppant slurries, conventional methods focus on manipulating the rheological properties of the liquid medium by adding a sufficient amount of viscosifier, for example, a natural or synthetic polymer, into the slurry to form a viscoelastic fluid. It is not unusual that a polymer is used together with a foaming agent to improve the rheology and to reduce cost.
[0006] Flotation has been used in minerals engineering for the separation of finely ground valuable minerals from other minerals. Crude ore is ground to fine powder and mixed with water, collecting reagents and, optionally, frothing reagents. When air is blown through the mixture, hydrophobic mineral particles cling to the bubbles, which rise to form froth on the surface. The waste material (gangue) settles to the bottom. The froth is skimmed off, and the water and chemicals are removed, leaving a clean concentrate. The process, also called the froth-flotation process, is used for a number of minerals.
[0007] The primary mechanism in such a flotation process is the selective aggregation of micro-bubbles with hydrophobic particles under dynamic conditions to lift the particles to the liquid surface. The minerals and their associated gangue usually do not have sufficient hydrophobicity to allow bubbles to attach. Collecting agents, known as collectors, are chemical agents that are able to selectively adsorb to desired minerals surfaces and make them hydrophobic to permit the aggregation of the particles and micro-bubbles and thus promote separation. Frothers are chemical agents added to the mixture to promote the generation of semi-stable froth. In the so-called reverse flotation process, the undesired minerals, such as silica sand are floated away from the valuable minerals which remain in the tailings. The reverse flotation of silica is widely used in processing iron as well as phosphate ores.
[0008] A wide variety of chemical agents are useful as collectors and frothers for flotation of silica particles. Amines such as simple primary and secondary amines, primary ether amine and ether diamines, tallow amines and tall oil fatty acid/amine condensates are known to be useful collectors for silica particles. It is well established that these chemical compounds strongly adsorb to sand surface and change the sand surface from hydrophilic to hydrophobic to allow form stable sand/bubbles aggregations. The preferred collectors are amine collectors having at least about twelve carbon atoms. Collectors useful in the present invention are amines including simple primary and secondary amines, primary ether amine and ether diamines, tallow amines and tall oil fatty acid/amine condensates. Examples of such collectors include propanamine, 3-nonyloxy-; 1,3-propanediamine, N-tridecyloxy-3,1-propanediyl-; the condensate of diethylenetetraamine and tall oil fatty acid, C 16 -C 18 tallow amine, decylamine, dodecylamine, dihexyl amine, tetradecyloxypropyl amine, dodecyloxypropyl amine, octadecyl/hexadecyloxypropyl amine, isododecyloxypropyl amine, isotridecyloxypropyl amine, dodecyl-1,3-propanediamine, hexadecyl-1,3-propanediamine, tallow-1,3-propanediamine and the condensate of an excess of fatty acids with diethanolamine. Alkanol amines with short carbon chains, such as C 1-6 alkanol amines, or short carbon chain amine such as hexylamine can also be combined with long carbon chain amine collectors to enhance the flotation. Such collectors and related compositions for silica are well known in the art. More details can be found in U.S. Pat. Nos. 2,312,387; 2,322,201; 2,710,856; 4,234,414; and 5,124,028; S. Takeda and S. Usui in Colloid and Surfaces, 29, 221-232, 1988; and J. L. Scott and R. W. Smith in Minerals Engineering, Vol. 4, No. 2, 141-150, 1991, which are incorporated herein by reference. Other possible collectors are oleate salts which normally need presence of multivalent cations such as Ca++ or Mg++ to work effectively.
[0009] Compounds useful as frothers include low molecular weight alcohols including methyl isobutyl carbinol (MIBC), amyl, hexyl, heptyl and octyl, and diethyl isohexyl alcohols, pine oil and glycol ethers. In floatation process, the collectors and frothers can be used alone or in combination.
[0010] For the mineral having natural hydrophobic surface such as coal, the mostly common used collectors are hydrocarbon oils such as kerosene, fuel oil, or a C 5 to C 8 hydrocarbon. In coal flotation, the collectors and frothers can be used alone or in combination. For example, small amount of isooctane or kerosene can be used alone or in combined with pine oil, or small quantity of MIBC or pine oil or hexyl alcohol can acts as both collector and frother in coal flotation.
[0011] Such flotation methods are not used in making resin coated proppant slurries.
SUMMARY OF THE INVENTION
[0012] A slurry composition including resin coated proppant and an aqueous liquid.
[0013] A slurry composition including resin coated proppant, sand and an aqueous liquid.
[0014] A slurry composition including resin coated proppant, an aqueous liquid and a collector.
[0015] A slurry composition including resin coated proppant, sand, an aqueous liquid and a collector.
[0016] A slurry composition including resin coated proppant, an aqueous liquid and a frother.
[0017] A slurry composition including resin coated proppant, sand, an aqueous liquid and a frother.
[0018] The slurry composition can be used in different applications including hydraulic fracturing, wellbore clean out, sand control operations in unconsolidated formations.
[0019] In one aspect, the present invention relates to a method of making a resin coated proppant slurry composition, the method comprising the steps of: introducing resin coated proppants; mixing the resin coated proppants with an aqueous liquid; and attaching micro-bubbles of sufficient stability to a resin coated proppant surface; wherein the fluidity of the resin coated proppant slurry is increased and transportation of the resin coated proppants is facilitated.
[0020] In another aspect, the present invention relates to a method of making a resin coated proppant slurry composition, the method comprising the steps of: introducing resin coated proppants; mixing the resin coated proppants with an aqueous liquid; and creating a plurality of cavities among neighbouring resin coated proppants; wherein the fluidity of the resin coated proppant slurry is increased and transportation of the resin coated proppants is facilitated.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Apart from the conventional approaches, in the present invention, attention is turned away from the rheology of the carrying fluid, and instead focused on the proppant, in particular, resin coated proppants. While in each case the characteristics of resin coated proppant (in this embodiment namely its size distribution and density) are constants, the present invention is directed to improving slurry fluidity and stability by “lifting” the proppants instead of suspending them by the liquid medium.
[0022] In one embodiment, the lift is achieved by attaching micro-bubbles of sufficient stability to the resin coated proppant surface. Alternatively, cavities are created among neighboring resin coated proppant grains. The micro-bubbles or cavities attached to the resin coated proppant surfaces help lift them up, due to the resulting increased buoyancy.
[0023] In the present invention, the basic principle of flotation is applied to the preparation of aqueous resin coated proppant slurries for transporting the resin coated proppant, which has wide applications, especially in oil field. These applications include hydraulic fracturing, proppant flowback control, wellbore cleanout, sand control operation in unconsolidated formations, sand cleanout in pipeline and sand jetting. The resin coated proppants used in these applications typically range in size from 10 to about 100 mesh. All these applications generally are carried out under dynamic conditions, where turbulence normally exists.
[0024] In the present invention, the surfaces of resin coated proppant grains are hydrophobic, while the hydrophobicity can vary from different surface coating. The hydrophobic surface of the resin coated proppant promotes aggregation with micro-bubbles in an aqueous liquid, particularly under dynamic conditions. The term of the aqueous liquid includes water, water containing certain amount of organic or inorganic salts, and water containing small amounts of alcohols or other organic solvents. The aggregation with bubbles provides the resin coated proppants with increased buoyancy and therefore greatly improves the fluidity and stability of the slurry, without employing the viscosifiers.
[0025] There are different ways to make resin coated proppant slurries according to the present invention. For example, resin coated proppants can be mixed with water under high agitation, preferably in the presence of gas such as air, nitrogen or carbon dioxide while pumping into a well. It is noted that the conventional surfactants used in the fracturing fluid at normal loading is detrimental to making the slurries according to the present invention. These surfactants, which are normally anionic or non-ionic surfactants or mixtures of surfactants, are added into the fracturing fluid to enhance the flow back of the fracturing fluid after the treatment, by reducing the surface tension of the fluid as low as possible. Without being bound by theory, it is believed that when the surface tension of the aqueous liquid is reduced below a certain value, due to the presence of sufficient amount of surfactant, for example, the micro-bubbles are not capable of being attached to the particulate surface with sufficient stability, and thus forming no particulate/bubble aggregations. Therefore, different from the conventional approach in water fracturing treatment where water or brines is used as fracturing fluid, it is in general undesirable to add anionic or non-ionic surfactants into the resin coated proppant slurry according to the present invention, or only to add them in very small amounts, which is below the critical micelle concentration of the surfactant. The slurry can also be prepared in situ, where resin coated sand, for example, is mixed with water under dynamic conditions, for example, in wellbore cleanout and sand cleanout in pipeline, where liquid flow of high rate is normally applied.
[0026] In water fracturing treatment, proppant such as sand settles quickly on the bottom of the fracture and leave the upper and front portions of the fracture unpropped. The less propped fractures compromise the effectiveness of the treatment. In the present invention, similar sized resin coated proppants, for example resin coated sand, can be mixed together with the regular sands and pumped into the formation. Due to the attachment of bubbles to their surfaces, the resin coated sands are more floatable and are more readily to fill up the upper and front portion of the fracture, while the regular sands settle down on the bottom of the fracture. The more wide distribution of the proppants in the fracture provides larger conductive channels resulting in higher production. In addition, since the resin coated proppants are normally several times more expensive than the regular sands, mixing of sands with resin coated proppants reduces the cost significantly.
[0027] Another aspect of the present invention is the slurry composition comprising of an aqueous liquid, resin coated proppant, and a collector or a frother, or a mixture of the collector and the frother. One type of the collectors includes hydrocarbon oils, for example, kerosene, fuel oil, or a C 5 to C 8 hydrocarbons. One type of frothers includes low molecular weight alcohols including methyl isobutyl carbinol (MIBC), amyl, hexyl, heptyl and octyl, and diethyl isohexyl alcohols, pine oil and glycol ethers. In the present invention, the collectors and frothers can be used alone or in combination. For example, a small amount of isooctane or kerosene can be used alone or in combined with pine oil, or MIBC or pine oil or hexyl alcohol can be used alone. Another type of collectors is primary and secondary amines, primary ether amine and ether diamines, tallow amines and tall oil fatty acid/amine condensates, which are known to be useful collectors for floating silica particles. For example, this type of collectors can be used when the resin coated proppant and sand are used together in making the slurry according to the present invention.
[0028] In general, the collectors have stronger tendency to adsorb on the particulate surfaces than to disperse or dissolve in the aqueous liquid. Depending on the amount of resin coated proppants in the slurry, the addition of the collectors or frothers or their mixtures is generally very small, in the order of ppm. The addition of the collectors or the frothers or their combination enhances the bubble attachment to the particulate surfaces and therefore increases the floatability of the resin coated proppants. The slurry compositions according to the present invention can find many applications, for example, they can be used to effectively transport the resin coated proppants into the fractures during the hydraulic fracturing operations.
[0029] The resin coated proppant slurries can be prepared at the surface or under a subterranean formation in situ where the proppant, the aqueous fluid, and a frother, such as hexylalcohol are mixed together under dynamic situations. For example, during a fracturing operation, a collector or a frother or a collector/frother mixture can be added into water and mixed with the resin coated proppant as slurry under high pumping rate to transport the proppant into formation. Optionally, the resin coated proppant and sand are used together. Preferably, nitrogen or carbon dioxide gas is mixed into the slurry. Similarly in wellbore sand cleanout, water containing the collector is mixed with resin coated proppant, for example, resin coated sand, in situ at high flow rate and carries the proppant out the wellbore. Optionally, nitrogen or carbon dioxide gas can be mixed with the fluid.
[0030] The following provides several non-limiting examples of the present invention.
Example 1
[0031] 100 ml of water and 25 grams of 20/40 US mesh resin coated proppant (SiberProp) were added into a glass bottles (200 ml). The bottles were vigorously shaken and then let to stand to allow the proppant to settle down. It was observed that bubbles are attached to the proppant surface, and moreover there were a layer of proppant floating on the top. When the bottles were tilted slowly, the settled proppant tended to move as cohesive masses.
Example 2
[0032] 100 ml of water and 25 grams of 20/40 US mesh resin coated proppant (SiberProp) and 25 grams of 20/40 regular frac sand were added into a glass bottles (200 ml). The bottles were vigorously shaken and then let to stand to allow particulates settle down. It was observed that bubbles are attached to the proppant surface while no bubble attached to the sand surface. All the sand settles to the bottom immediately while a layer of proppant floating on the top.
Example 3
[0033] 100 ml of water, 25 grams of 20/40 US mesh resin coated proppant (Atlas PRC) and one drop (˜0.03 ml) of hexyl alcohol were added into a glass bottles (200 ml). The bottles were vigorously shaken and then let to stand to allow the proppant to settle down. It was observed that bubbles are attached to the proppant surface, and moreover there were a layer of proppant containing about 30% of total proppants floating on the top. When the bottles were tilted slowly, the settled proppant tended to move as cohesive masses.
Example 4
[0034] 100 ml of water, 25 grams of 25/50 US mesh resin coated proppant (Black) and one drop (˜0.03 ml) of kerosene were added into a glass bottles (200 ml). The bottles were vigorously shaken and then let to stand to allow the proppant to settle down. It was observed that bubbles are attached to the proppant surface, and moreover there were a layer of proppant containing about 10% of total proppants floating on the top. When the bottles were tilted slowly, the settled proppant tended to move as cohesive masses.
Example 5
[0035] 100 ml of water, 25 grams of 20/40 US mesh resin coated proppant (Atlas PRC) were added into a glass bottles (200 ml). The bottles were vigorously shaken and then let to stand to allow the proppant to settle down. It was observed that bubbles are attached to the proppant surface, and moreover there were a layer of proppant floating on the top. Further, one drop (−0.03 ml) of Armeen DMHTD, an amine collector from Akzo Nobel, was added into the slurry and vigorously shaken and then let to stand to allow the proppant to settle down. More sand was observed floating on the top.
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A resin coated proppant slurry and a method for preparing a slurry is provided where the resin coated proppant particles are rendered less dense by attaching stable micro-bubbles to the surface of the resin coated proppants. A collector or frother may be added to enhance the number or stability of bubbles attached to the proppants. This method and composition finds use in many industries, especially in oil field applications.
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[0001] This application claims priority from U.S. Provisional Application No. 61/946,203, filed Feb. 28, 2014.
TECHNICAL FIELD
[0002] This invention relates to high production rock ripping tools, and more particularly to bucket type excavation and ripping tools for excavators and backhoes.
BACKGROUND
[0003] Excavation tools of the types described herein are typically mounted to conventional excavators or backhoes having a dipper stick, with the tool mounted on the dipper stick. The tools are employed for excavation of difficult-to-excavate intermediate substrate, e.g. substrate between the category of loose soil or loose gravel and the category of solid rock. Attempts have been made to develop tools that are effective and efficient in excavating intermediate substrate. For example, an excavation tool for the removal of substrate is described in Horton U.S. Pat. No. 7,739,815, and a multi-tooth bucket approach where several teeth are mounted on the back side of a bucket is described in Arnold U.S. Pat. Nos. 4,279,085 and 4,457,085. The complete disclosures of all of these references are incorporated here by reference. Each of these approaches has been found to have drawbacks, and none is seen to be particularly efficient or effective for excavation of intermediate substrate with high production, wide width, high capacity buckets.
SUMMARY
[0004] According to one aspect of the disclosure, a rock ripping tool mountable to an arm of an excavation machine for ripping engagement with a substrate comprises a tool body mounted for rotation from the arm, a pair of side plates and a curved back plate mounted to the tool body, a bottom plate having an angled front leading edge and mounted to span a space between the side edge plates, and a plurality of teeth comprising a first set of two or more teeth mounted to the angled front leading edge such that the tips of each tooth of the first set of two or more teeth lies on an arc having a first radius, a second set of one or more teeth mounted to at least one of the bottom plate and/or the back plate, such that the tips of each tooth of the second set of one or more teeth lies on an arc having a second radius greater than the first radius.
[0005] Implementations of this aspect of the disclosure may include one or more of the following additional features. The first radius and the second radius intersect at a common axis of the ripping tool. The rock ripping tool comprises at least a third set of one or more teeth mounted to the bottom plate and/or the back plate, such that the tips of each tooth of the third set of one or more teeth lies on an arc having a third radius greater than the first radius and greater than the second radius. Each tooth of the plurality of teeth is angled such that an angle between a line bisecting the tooth and a line perpendicularly bisecting the respective arc where the tip of the tooth lies on the arc is at an optimum angle. Each tooth in the plurality of teeth is at the optimum angle. The optimum angle is in the range of about 35° to about 70°, e.g. the optimum angle is approximately 50°. The second set of teeth rips the substrate in a path between the paths of the teeth of the first set of two or more teeth. The side plates can have leading edges that define cutting profile edges. A lower portion of the back plate defines an outer surface lying on a radius having a center coaxial with at least one of the first radius and the second radius. Each tooth of the plurality of teeth is configured to engage the substrate sequentially and individually from each other tooth.
[0006] According to another aspect of the disclosure, a rock ripping tool having a tool body and mountable to an arm of an excavation machine for ripping engagement with a substrate comprises a first set of teeth comprising at least two teeth mounted to the tool body such that the tips of each of the at least two teeth of the first set of teeth lies on an first arc having a first radius, and a second set of teeth comprising at least one tooth mounted to the tool body such that the tip of each tooth of the at least one tooth of the second set of teeth lies on an second arc having a second radius greater than the first radius, wherein each tooth of the plurality of teeth is configured to engage the substrate independently from each tooth in the first set of teeth and each tooth in the second set of teeth.
[0007] Implementations of this aspect of the disclosure may comprise at least a third set of one or more teeth mounted to the bottom plate and/or the back plate, such that the tips of each tooth in the third set of one or more teeth lies on an arc having a third radius greater than the first radius and greater than the second radius.
[0008] Advantages of the new rock ripping tool include that the tool can have a relatively wider bucket, e.g. to increase production without increasing the number of teeth on the front leading edge. Rather, by providing teeth at the back of the bucket, i.e. behind the leading edge, deeper cuts can be made with each pass, thus reducing or eliminating grooves in the substrate material, while keeping a relatively large side view engagement angle between the teeth, assuring one tooth at-a-time engagement. The back teeth are arranged to cut relatively deeper, i.e. as compared to the teeth at the leading edge, with increased radii, also resulting in increased production. Since the number of teeth is relatively increased, the wear on each tooth is proportionately reduced. The rock ripping tool of the disclosure is designed in particular for use in ripping medium hard rock.
[0009] The details of one or more embodiments of the disclosure are set forth in the accompanying drawings and in 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
[0010] FIG. 1 is a somewhat schematic representation of a hydraulic excavator fitted with an example of the high production rock ripping tool of this disclosure.
[0011] FIG. 2 is a left front perspective view of the high production rock ripping tool of FIG. 1
[0012] FIG. 3 is a bottom view of the high production rock ripping tool of FIG. 1 .
[0013] FIG. 4 is a left rear perspective view of the high production rock ripping tool of FIG. 1 .
[0014] FIG. 5 is a rear view of the high production rock ripping tool of FIG. 1 .
[0015] FIG. 6 is an enlarged side view of the ripping excavation tool of FIG. 1 , e.g. a high production rock ripping tool of the disclosure, having multiple ripping teeth mounted to the tool in an arrangement with angular spacing between ripping teeth in a general direction of substrate ripping motion.
[0016] FIG. 7 is a schematic representing a cross-sectional view of a pattern of substrate material ripped from a substrate during use of a high production rock ripping tool of the disclosure.
[0017] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0018] Referring first to FIG. 1 , a hydraulic excavator 10 , e.g. of the type suited for use with a high production rock ripping tool 12 of the disclosure, has a chassis 14 , tracks 16 and 17 for mobility, and a cab 18 for an operator. Extending from the chassis 14 is a boom 20 pivotally attached to the chassis 14 and a dipper stick 24 pivotally attached to the outboard end of the boom. A hydraulic actuator 26 articulates the dipper stick 24 . A high production rock ripping tool 12 can be mounted to the outboard end of the dipper stick 24 of the hydraulic excavator 10 by means of a quick-change coupler mechanism 28 , or it can be mounted directly to the dipper stick and linkage. A second hydraulic actuator 30 articulates the high production rock ripping tool 12 generally about an axis, H (see, also, FIG. 6 ). A second axis, A, is an imaginary axis that is a combination of the rotational axis translation, which is preferably located near and generally above and forward of the dipper pivot rotation center, i.e., the axis, H, of hinge pin 32 , e.g. for ripping engagement, e.g., with the medium hard substrate, S.
[0019] Referring also to FIGS. 2 through 6 , the high production rock ripping tool 12 has a tool body including a tool body upper portion 34 , constructed for secure, releasable connection to the lower side of the quick-change mechanism 28 ( FIG. 1 ). The quick-connect coupler mechanism 28 , in turn, is connected to the dipper stick 24 and the hydraulic actuator 30 ( FIG. 1 ), or the tool can be connected directly to the dipper stick. Connected to the tool body upper portion 34 are two or more plates 36 that together generally form a tube. A set of rear and front side edge plates 38 , 40 are mounted at respective upper ends to opposite ends of the tool body upper portion 34 . Each side edge plate 38 , 40 extends generally perpendicular to the axis, A, of the high production rock ripping tool 12 . A curved back plate 42 is mounted to span a region between the side edge plates 38 and 40 . Also spanning side edge plates 38 , 40 , at a bottom aspect of the tool 12 , opposite the tool body upper portion 34 , a rear bottom plate segment 44 and mid bottom plate segment 46 . Also partially spanning the bottom of the rock ripping tool 12 is a front bottom plate segment 48 . The front bottom plate segment 48 is forward of the mid bottom plate segment 46 , which is forward of the rear bottom plate segment 44 . The front bottom plate segment 48 is attached to a bottom front portion of the forward side edge plate 40 , approximately perpendicular to the second forward edge plate 40 . As best seen, e.g., in FIGS. 2 and 4 , the rear bottom plate segment 44 , mid bottom plate segment 46 , and front bottom plate segment 48 do not necessarily lie on a plane and rather are angled relative to each other. In other implementations, the bottom plate 43 may be formed as a single, e.g. bent, plate having angled portions.
[0020] Referring, e.g., to FIG. 2 , the mid bottom plate segment 46 and front bottom plate segment 48 each has a plate leading edge 50 , 52 that together form a discontinuous front leading edge 54 for cutting engagement with the substrate, S. The front leading edge plate 54 is angled laterally by angle, B, of FIG. 3 , e.g. about 10° to about 35°. The angled front leading edge plate 54 may or may not have teeth mounted thereto; however, in the implementation shown in the present drawings, a first set of front teeth 60 is mounted to the front leading edge plate 54 . The side edge plates 38 , 40 , and teeth 62 of the first set of teeth 60 , are laterally spaced apart along the axis A, and the teeth are positioned in a direction of substrate-engagement motion.
[0021] The side edge plates 38 , 40 can be beveled at their front aspect, e.g. to provide side cutting edges, and are shaped, thus providing a rearward side leading edge 39 and tooth 62 C and a forward side leading edge 41 and tooth 62 A that are spaced apart and approximately parallel to each other along the axis, A, e.g. as shown in FIGS. 2 and 3 . Additional tooth 62 B is intermediately spaced along the front leading edge 54 at the front-most portion of mid bottom plate segment 46 .
[0022] The plate leading edges 50 , 52 of front leading edge 54 are also beveled to provide forward bottom cutting edges for cutting the packed substrate S. Additionally, the plate leading edges 50 , 52 of front leading edge 54 can be scalloped, e.g. to help slice through the hard packed substrate, as shown, e.g., in FIG. 2 .
[0023] Referring further to FIGS. 3-5 , in preferred implementations, the rock ripping tool 12 has three sets of removable teeth 60 , 70 , 80 mounted to the high production rock ripping tool 12 . The first tooth set 60 includes three teeth 62 A, 62 B, 62 C, which are mounted along on the front leading edge 54 . Each of the teeth 62 A, 62 B, 62 C of the first set of teeth 60 is mounted to a tooth adapter 90 , respectively, which is easily welded at the tip of the associated side edge plate 38 or the forward edge s of the rear, mid, and/or front bottom plate segments 44 , 46 , 48 , respectively, or the bottom plate 43 . Two teeth 72 A, 72 B, in a second tooth set 70 , are mounted on tooth adaptors 92 , 94 positioned to the bottom and rear of the rock ripping tool 12 . The forward tooth 72 A of the second tooth set 70 is mounted to the rear bottom plate segment 44 , and the rearward tooth 72 B of the second tooth set 70 is mounted to the curved back plate 42 . A third tooth set 80 contains a single tooth 82 A, which is mounted upon a highly curved tooth adaptor 96 positioned at the rear of curved back plate 42 .
[0024] Referring to FIG. 6 , the three teeth 62 A, 62 B, 62 C of first tooth set 60 are all positioned to lie on arc 66 having a radius, R 1 , centered on axis, A, near and generally above and forward of the dipper pivot rotation center, i.e. axis, H, of hinge pin 32 . The two teeth 72 A, 72 B of the second tooth set are positioned to lie on arc 76 having the same center, A, as arc 66 , but with a relatively larger radius, R 2 . The tooth 82 A of the third tooth set 80 is positioned to lie on arc 86 , also of the same center, A, and having a radius, R 3 , larger than either of the radius, R 1 , and radius, R 2 . As seen from the side, the teeth are not positioned to lie in a common plane. Each tooth is spread at a similar engagement angle, e.g., about 15 to 18 degrees, to approximately equally spread the teeth for engagement with the substrate, S.
[0025] Each set of teeth 60 , 70 , 80 is angled such that an angle Z 1 , Z 2 , Z 3 for each set of teeth, being the angle between the bisection of each tooth and the radii R 1 , R 2 , R 3 of the respective arcs 66 , 76 , 86 , is optimized to provide maximum penetration in the substrate. That is, all of the teeth are angled such that angles Z 1 , Z 2 , Z 3 are equalized to an optimum ripping angle, Z. The optimum angle, Z, depends on tooth manufacture, but typically lies in the range of about 35° to about 70°, or approximately 50°.
[0026] Referring to FIG. 5 , the three teeth 62 A, 62 B, 62 C, i.e. of the first tooth set 60 , are positioned to be laterally spaced from each other generally along the axis, A, of the high productions rock ripping tool 12 . In this implementation, the ripping teeth 62 A, 62 B, 62 C are equally spaced apart from each other, creating generally uniform intervening gaps 68 .
[0027] The next two teeth 72 A, 72 B, i.e. of second tooth set 70 , are positioned to be laterally spaced apart from each other generally along the axis, A, creating intervening gap 78 between the two teeth. In this implementation, the teeth 72 A, 72 B are equally spaced apart and span the width of the tool 12 . The two teeth 72 A, 72 B are also laterally positioned between the front three teeth 62 A, 62 B, 62 C, i.e. in the intervening gaps 68 between the teeth of the first tooth set 60 .
[0028] The rear tooth 82 A, i.e. of the third tooth set 80 , is positioned near the lateral center of the tool, i.e., within intervening gap 78 between teeth 72 A, 72 B.
[0029] Referring in particular to FIG. 3 , each tooth 62 A, 62 B, 62 C of the disclosure has a first ripper tooth portion 63 , terminating in a first ripper tooth tip 64 , and at least a second ripper tooth portion 65 , terminating in a second ripper tooth tip 66 . The twin or double tiger points or tips 64 , 66 of first and second ripper tooth portions 63 , 65 , respectively, are dimensionally spaced apart along the axis, A, by a dimension, W, e.g. about one-third of the length of the tooth.
[0030] The edge plates 38 , 40 with the bottom plate 43 , consisting of rear bottom plate segment 44 , mid-bottom plate segment 46 , and front bottom plate segment 48 , provide a bucket volume, V ( FIG. 2 ), of predetermined capacity for receiving material excavated from the substrate, S. The bucket volume, V. can be about 0.1 cubic yard for use with a mini (e.g., 6,000 pound weight) excavator to 6 or more cubic yards for use with a large (e.g., 300,000 pound) excavator. The rearward side edge plate 38 is shaped to support the bottom plate segments 44 , 46 and tooth adapter 90 (to which a tooth 62 A is mounted, e.g. by pins (not show)), while also limiting side spillage, thus providing for maximum capacity of excavated substrate material. The width of the high production rock ripping tool 12 may be made larger than other rock ripping buckets, thereby permitting increased capacity. For example, the width of the tool can be 18 inches for use with a mini (e.g., 6,000 pound weight) excavator to 72 inches for use with a large (e.g., 300,000 pound) excavator. The bucket volume, V, of the high production rock ripping tool 12 fills and empties easily, thereby permitting the operator to scoop excavated materials efficiently.
[0031] The high production rock ripping tool of FIG. 1 thus improves the efficiency of excavating hard packed substrate, e.g. when compared to prior art tools, by focusing the breakout force one tooth at a time. As the operator is excavating hard packed substrate, the tool is rolled toward the operator such that the first tooth 62 A alone engages the material first. The concentration of machine breakout force on one tooth provides a concentration of the forces that are high enough to easily break up hard packed substrate, S, such as medium hard rock.
[0032] During operation, the high production rock ripping tool 12 is pivoted all the way back at the end of the dipper stick 24 , and extended out as far forward of the chassis 14 as possible. The tool 12 is then lowered until the first tooth 62 A of the first tooth set 60 engages the substrate, S. The rock ripping tool 12 is then drawn downward, and in ripping motion, the second tooth, i.e. the tooth 62 B next adjacent to tooth 62 A, engages the substrate. Looking at the first tooth and the second tooth together, the first tooth engages with the hard packed substrate with full breakout force. When the second tooth engages the substrate, some of the load is shared with the first tooth. As the tool is rolled forward, the third tooth 62 C of first tooth set 60 then engages the substrate, S, and the load is shared between the several teeth that have engaged with the substrate. Throughout a good portion of the digging of the medium hard rock substrate, the tool 12 will have only one or two teeth engaged at any one instant due to the rolling operation of the bucket, thus always providing high forces for simplifying the excavation of the hard material.
[0033] Referring to FIG. 7 , there is shown a cross-sectional schematic representation of the pattern of profiles by which substrate, S, is ripped. Since, as described above, no two teeth are in alignment, when the high production rock ripping tool 12 is rolled, each tooth engages separately, so that each tooth portion fractures the groove cut by the preceding ripper tooth or teeth. The top three trapezoidal shapes 69 A, 69 B, 69 C represent the profile of material removed from the substrate, S, by the three teeth 62 A, 62 B, 62 C of the first tooth set 60 , located on the front leading edge 54 , after the tool 12 has been rotated and translated over the medium hard rock material. The flat bottom 100 of each trapezoid-shaped profile indicates the result following the cutting action of each tooth in the first tooth set 60 , and the angled sides 102 represent the broken out material. The flat bottoms 100 of the top profiles are at a depth, 67 , from the surface of the substrate. After the first three teeth 69 A, 69 B, 69 C have passed, the teeth have left the two raised grooves of material 104 located in the gaps 68 .
[0034] The next two lower profiles 79 A, 79 B represent the next two teeth 72 A, 72 B of the second tooth set 70 passing through, ripping out the grooves with a deeper cut of relatively larger radius, removing the sections of material 79 A, 79 B to a depth 77 . The two teeth 72 A, 72 B also remove the raised grooves of material 104 in gaps 68 while leaving a new raised portion 106 between the sections of material 79 A, 79 B, in the gap 78 . The bottom shape or profile 89 A represents the final, deepest cut, performed by rear tooth 82 A of the third tooth set 80 , with the relatively largest radius R 3 , which removes material to the lowest depth, 87 , while also removing the raised groove of material 106 . Once all the teeth have engaged and cut through the substrate, S, a staggered form of a “V” shape or profile has been cut into the substrate material (e.g., rather than a flat bottom).
[0035] The rear tooth can also be used as a pick when the tool is in the rolled forward position.
[0036] A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, six teeth are described in one implementation of a high production rock ripping tool of this disclosure. In other implementations, more than or less than six teeth may be employed, positioned upon the surface of the tool. For example, four teeth may be positioned in the first tooth set 60 on the front leading edge 54 . In this implementation, the number of teeth in the second group 70 could still be two, and the third tooth set 90 could still include a single tooth in the center, for a total of seven teeth.
[0037] Also, other arrangements of the teeth in the sets of teeth may be employed. For example, although in the implementation of the disclosure shown in the drawings the right outboard tooth 62 A is forward, left outboard tooth 62 C is rearward, and intermediate or central tooth 62 B is in the middle, other arrangements may be employed according to the disclosure. For example, the center tooth 62 B could be the first engaging tooth, with the right tooth 62 A engaging next, followed by the left tooth 62 C.
[0038] Referring to FIGS. 3-6 , in a preferred implementation, a lower portion 47 of the curved back plate 42 has an outer surface 49 with a radius R 4 having a center, A, that is co-axial with respective arcs 66 , 76 , 86 of the sets of tooth tips. This feature makes it easier to position and attach the tooth adaptors 92 , 94 (or shanks) for teeth 72 A and 72 B on the curved back plate 42 , and also helps to keep the shanks as short as possible, which serves to reduce stresses on the curved back plate. This arrangement also reduces wear on the outer and bottom surfaces of the bucket 12 because as the bucket moves parallel to the ripped rock surface of the substrate forming the bottom of the trench, the bottom surface of the bucket is less exposed for scraping engagement along the bottom of the trench. In contrast, bottom surfaces of some buckets of conventional design have a “heel” configuration that wears quickly due to its exposure and due to its tendency for scraping engagement along the substrate surface forming the bottom of the trench.
[0039] Also, in the implementation of the disclosure shown in the drawings, the high production rock ripping tool 12 is represented as being a bucket; however, other implementations are also possible. For example, rather than a closed bucket with side and bottom plates supporting attached teeth, a set of shanks could instead be attached to the tool body upper portion 34 in an arrangement to rip the substrate, S. For example, the teeth in a first set of staggered teeth 60 positioned relative to the axes of rotation and to the other teeth as described above may each be mounted to the end region of a shank. A second set of staggered teeth 70 that rip between, and deeper than, the first set 60 may also be mounted on shanks, and then a final tooth or set 80 positioned to rip between, and deeper than, the second set 70 would be mounted on still another shank. Each set of subsequent ripping teeth would rip on a relatively larger radius between the previous teeth, e.g. as described above.
[0040] Accordingly, other embodiments are within the scope of the following claims.
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A rock ripping tool mountable to an excavation machine for engagement with a substrate has a rotatable tool body, a pair of side plates and a curved back plate mounted to the body, a bottom plate with an angled leading edge mounted to span a space between side plates, and a plurality of teeth, including a first set mounted to the front edge, the tip of each tooth lying on an arc having a first radius, a second set mounted to the bottom and/or back plate, the tip of each tooth lying an arc having a second radius greater than the first radius, and a third set of teeth mounted to the bottom plate and/or the back plate, with the tip of each tooth lying on an arc having a third radius greater than the first and second radii. Each tooth is configured to engage the substrate sequentially and individually.
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FIELD OF THE INVENTION
The invention relates to the medical device field, and more particularly, to a digital portable pulse oximeter and battery-powered control method thereof. The automatic switching of the power supply is achieved by adding a Hall circuit, and the data displayed is allowed to always face the users by adding an orientation sensor to the circuit.
BACKGROUND ART
A pulse oximeter is a non-invasive medical device for continuously monitoring the blood oxygen saturation of arteries in a human body. As a common device of anesthesia monitoring and intensive care in hospitals, the device has also been widely used in a variety of mobile cares and sleep cares at places other than hospitals. The development of both family and community medical healthcare systems has put forward new requirements on the design and manufacture of pulse oximeters; in particular, it is highly desirable that wearable pulse oximeters that are characterized by low price yet high performance and are widely adaptable to families and medical treatment network at community level are provided.
Today, the pulse oximeters commercially available in the domestic and overseas markets generally fall into two categories—analog type and digital type, which can also be divided into desktop type and portable type. Most of the analog pulse oximeters with complicated circuits are desktop type, and when a desktop pulse oximeter is used, signal is transmitted to the instrument through a finger clamp and cable. It is inconvenient for users to move with cable towed, and the cable also makes the guardianship inconvenient, hereby the using occasions are limited. However, with the development of digital circuit technology, a battery-powered portable pulse oximeter with no cable is widely used. Being battery-powered, the pulse oximeter enters operational state after the power supply is turned on, whereas the pulse oximeter will do futile actions and continue consuming the power supply in a state of power-on when no measurement being carried out, which thereby shortens the effective operational time of battery. At the same time, the display of the portable pulse oximeter is disposed on the finger clamp, so the orientation of the finger clamp changes with the users' move and the data displayed can not face the users, which makes the users' reading difficult.
SUMMARY OF THE INVENTION
The object of this invention is to put forward a technical scheme of a digital portable pulse oximeter and battery-powered control method thereof in view of the above problems. In this technical scheme, the automatic switching of the power supply is achieved by adding a Hall circuit, and the data displayed is allowed to always face the users by adding an acceleration sensor to the circuit.
The object of the present invention is achieved through the technical scheme as described below:
A digital portable pulse oximeter comprising a housing body. The said housing body consists of an upper housing body and a lower housing body. The upper housing body and the lower housing body are disposed such that they are stacked together. One end of both the upper and lower housing body is the measurement end where a finger is placed. A pivot and a reset spring disposed between the upper housing body and the lower housing body enable them to be opened and closed at the measurement end. A display window is disposed at outside of and atop the upper housing body, with a display disposed inside the display window. A power supply battery and a measurement analysis circuit are also disposed in the housing body. The measurement analysis circuit comprises a light-frequency converter, a red infrared light emitting diode, a light-emitting driving circuit and a microprocessor. The microprocessor has a power supply stay-on output pin, the light-frequency converter and the light emitting diode are respectively disposed in the upper housing body and the lower housing body at the measurement end of the housing body. The red infrared light emitting diode connects to the light-emitting driving circuit, the interface circuit of the microprocessor connects to the light-emitting driving circuit, the light-frequency converter and the display, respectively; Wherein, an acceleration sensor and a power supply switching-control circuit are also disposed in the housing body, the electrical signal of the acceleration sensor connects to the interface circuit of the microprocessor, the power supply switching-control circuit comprises a Hall switch sensor, a magnet and a switch circuit. The Hall switch sensor and the magnet are respectively disposed in the upper housing body and the lower housing body at the measurement end of the housing body, the magnet induces the output pin of the Hall switch sensor to generate a high-low potential change through the opening and closing of the upper housing body and the lower housing body, the switch circuit includes a dual-input logic control gate circuit and a power switch device, the output pin of the Hall switch sensor connects to one input end of the dual-input logic control gate circuit, the power supply stay-on output pin of the microprocessor connects to the other input end of the dual-input logic control gate circuit, the output end of the dual-input logic control gate circuit connects to the control pin of the power switch device, the input of the power switch device connects to the power supply battery, and the outputs of the power switch device connect to the measurement analysis circuit and the display.
The dual-input logic control gate circuit consists of four dual-input NAND gates, which are the first dual-input NAND gate, the second dual-input NAND gate, the third dual-input NAND gate and the fourth dual-input NAND gate, respectively. The two input ends of the first dual-input NAND gate connect to the output pin of the Hall chip after they are shorted, the output of the first dual-input NAND gate connects to one input of the second dual-input NAND gate, the other input of the second dual-input NAND gate connects to the output of the fourth dual-input NAND gate, the two input ends of the third-dual NAND gate connect to the output of the second dual-input NAND gate after they are shorted out, the output of the second dual-input NAND gate simultaneously connects to one input of the fourth dual-input NAND gate, the other input of the fourth dual-input NAND gate connects to the power supply stay-on output pin of the microprocessor, and the output of the third dual-input NAND gate connects to the control pin of the power switch device, the said power switch device is a P-channel power FET.
After they are shorted out, the two input ends of the first dual-input NAND gate connect to a 100K ohmics resistance and a magnetic bead concatenated in series. One end of the magnetic bead connects to the negative pole of the battery, and the concatenated end of the magnetic bead and the resistance is the negative pole of the power supply of the measurement analysis circuit.
A digital portable pulse oximeter power supply control method comprising a housing body consisting of an upper housing body and a lower housing body, which are disposed such that they are stacked together, one end of both the upper housing body and the lower housing body is a measurement end where a finger is placed, a pivot and a reset spring are disposed between the upper housing body and the lower housing body enabling them to be opened and closed at the measurement end, a power supply battery and a measurement analysis circuit are disposed in the housing body, the measurement analysis circuit comprises a microprocessor having a power supply stay-on output pin. A Hall switch sensor, a magnet and a switch circuit are also disposed in the housing body, the Hall switch sensor and the magnet are respectively disposed in the upper housing body and the lower housing body at the measurement end of the housing body, the magnet induces the output pin of the Hall switch sensor to generate a high-low potential change through the opening and closing of the upper housing body and the lower housing body, the switch circuit includes a dual-input logic control gate circuit and a power switch device, the output pin of the Hall switch sensor connects to one input end of the dual-input logic control gate circuit, the power supply stay-on output pin of the microprocessor connects to the other input end of the dual-input logic control gate circuit, the output end of the dual-input logic control gate circuit connects to the control pin of the power switch device, the input of the power switch device connects to the power supply battery, and the output of the power switch device connects to the measurement analysis circuit of the oximeter, the said power supply control method is:
a. The battery powers the measurement analysis circuit and the display of the oximeter, i.e., the upper housing body and the lower housing body of the oximeter at the measuring end are opened, the output pin of the Hall switch sensor generates a high potential, which causes the output of the dual-input logic control gate circuit to control the power switch device into conduction;
b. Within a certain time, the microprocessor determines whether a blood oxygen signal is measured, i.e., whether a finger has ever been placed in the oximeter within a certain time.
b1. If there is a blood oxygen signal measured, the power supply will stay on, i.e., the power supply stay-on output pin of the microprocessor outputs a power supply stay-on signal;
b2. If there is no blood oxygen signal measured, a signal requiring to cut off the power supply will be sent out, i.e., the power supply stay-on output pin of the microprocessor outputs a signal of cutting off the power supply stay-on;
c. The microprocessor determines whether the upper housing body and the lower housing body at the measurement end of the oximeter housing body are still open; That is, whether the output pin of the Hall chip is still generating a high potential.
c1. If the output pin of the Hall switch sensor generates a high potential, the power supply will stay on;
c2. If the output pin of the Hall switch sensor generates a low potential, the output of the dual-input logic control gate circuit will control the power switch device into non-conduction, and the power supply will be cut off.
The said certain time is 5 seconds.
The advantageous effects of the present invention compared with the prior art are: The users can always read the data from the front side no matter which way they move; The present invention can turn on the pulse oximeter automatically just by inserting a finger, without having to press the switch button, and cut off the power supply by pulling out the finger, as well as judge intelligently whether to continue the measurement after the finger has been pulled out. If yes, the power supply will stay on, which reduces the energy waste and low efficiency caused by the restarting program initialization, improves the use efficiency of the battery and prolongs the battery usage time.
Bellow, the present invention will be described in detail with reference to the drawings and embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of this invention;
FIG. 2 is a circuit diagram of this invention;
FIG. 3 is a diagram of the power supply switching-control circuit of this invention;
FIG. 4 is a circuit diagram of this invention with a specific power supply switch circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Embodiment 1
Referring to FIG. 1 and FIG. 2 , an embodiment of the digital portable pulse oximeter comprising a housing body 1 . The said housing body consists of an upper housing body 1 - 1 and a lower housing body 1 - 2 . The upper housing body and the lower housing body are disposed such that they are stacked together. One end of both the upper and lower housing body is the measurement end 1 - 3 where a finger 2 is placed. A pivot 1 - 4 and a reset spring 1 - 5 disposed between the upper housing body and the lower housing body enable them to be opened and closed at the measurement end. A display window 1 - 6 is disposed at outside of and atop the upper housing body, with a display 3 disposed inside the display window. A power supply battery 4 and a measurement analysis circuit 5 are also disposed in the housing body. The measurement analysis circuit comprises a light-frequency converter 5 - 1 , a red infrared light emitting diode 5 - 2 , a light-emitting driving circuit 5 - 3 and a microprocessor 5 - 4 . The microprocessor has a power supply stay-on output pin 5 - 4 - 1 , the light-frequency converter and the light emitting diode are respectively disposed in the upper housing body and the lower housing body at the measurement end of the housing body. The red infrared light emitting diode connects to the light-emitting driving circuit, the interface circuit of the microprocessor connects to the light-emitting driving circuit, the light-frequency converter and the display, respectively; wherein, an acceleration sensor 6 and a power supply switching-control circuit 7 are also disposed in the housing body, the electrical signal of the acceleration sensor connects to the interface circuit of the microprocessor. Referring to FIG. 3 and FIG. 4 , the power supply switching-control circuit comprises a Hall switch sensor 7 - 1 , a magnet 7 - 2 and a power supply switch circuit. The Hall switch sensor and the magnet are respectively disposed in the upper housing body and the lower housing body at the measurement end of the housing body, the magnet induces the output pin of the Hall switch sensor to generate a high-low potential change through the opening and closing of the upper housing body and the lower housing body, the power supply switch circuit includes a dual-input logic control gate circuit 7 - 3 and a power switch device 7 - 4 , the output pin 7 - 1 - 1 of the Hall switch sensor connects to one input end of the dual-input logic control gate circuit, the power supply stay-on output pin of the microprocessor connects to the other input end of the dual-input logic control gate circuit, the output end of the dual-input logic control gate circuit connects to the control pin of the power switch device, the input of the power switch device connects to the power supply battery, and the outputs of the power switch device connect to the measurement analysis circuit, the display and the acceleration sensor.
The dual-input logic control gate circuit consists of four dual-input NAND gates, which are the first dual-input NAND gate 8 , the second dual-input NAND gate 9 , the third dual-input NAND gate 10 and the fourth dual-input NAND gate 11 , respectively. The two input ends of the first dual-input NAND gate connect to the output pin of the Hall chip after they are shorted out, the output of the first dual-input NAND gate connects to one input of the second dual-input NAND gate, the other input of the second dual-input NAND gate connects to the output of the fourth dual-input NAND gate, the two input ends of the third-dual NAND gate connect to the output of the second dual-input NAND gate after they are shorted out, the output of the second dual-input NAND gate simultaneously connects to one input of the fourth dual-input NAND gate, the other input of the fourth dual-input NAND gate connects to the power supply stay-on output pin of the microprocessor, and the output of the third dual-input NAND gate connects to the control pin of the power switch device, the said power switch device is a P-channel power FET.
In order to protect the measurement analysis circuit from the interference of the peripheral 50 Hz magnetic field, in this embodiment, the two input ends of the first dual-input NAND gate, after they are shorted out, connect to the 100K ohmics resistance 12 and the magnetic bead 13 concatenated in series. One end of the magnetic bead connects to the negative pole of the battery, and the concatenated end of the magnetic bead and the resistance is the negative pole 14 of the power supply of the measurement analysis circuit; Wherein, the magnetic bead is a plug-in magnetic bead, which is sized to allow a 500 mA current to produce a 30 ohmics impedance.
The acceleration sensor described in the embodiment employs either the SMB380 model or the MMA7455L model. The direction-selecting function achieved by the acceleration sensor of the present embodiment is different from that of the similar products utilizing optical direction sensors. The present acceleration sensor is a triaxial acceleration sensor with a high sensitivity, the operational voltage is 1.7V to 3.6V, which avoids the cumbersome design of the similar acceleration sensors that need a stable power supply. No LDO output is needed, the cost is controlled, and the circuit design space is saved. The acceleration sensor of the present embodiment needs no soft\hardware calibration and can identify the directions automatically, which eliminates the drawback of having to calibrate the acceleration sensor in different regions; The acceleration sensor of the present embodiment is also featured by a quick response, a high sensitivity, a low power consumption, and a simple circuit connection and so on.
The model of the power switch device in the embodiment is SI2301DS FET.
The model of the Hall switch sensor in the embodiment is BU52011HFV Hall device.
Embodiment 2
Referring to embodiment 1, the contents disclosed in embodiment 1 should also be regarded as the contents of the present embodiment. A digital portable pulse oximeter power supply control method comprising a housing body consisting of an upper housing body and a lower housing body, which are disposed such that they are stacked together, one end of both the upper housing body and the lower housing body is a measurement end where a finger is placed, a pivot and a reset spring are disposed between the upper housing body and the lower housing body enabling them to be opened and closed at the measurement end, a power supply battery and a measurement analysis circuit are disposed in the housing body, the measurement analysis circuit comprises a microprocessor having a power supply stay-on output pin; A Hall switch sensor, a magnet and a switch circuit are also disposed in the housing body, the Hall switch sensor and the magnet are respectively disposed in the upper housing body and the lower housing body at the measurement end of the housing body, the magnet induces the output pin of the Hall switch sensor to generate a high-low potential change through the opening and closing of the upper housing body and the lower housing body, the switch circuit includes a dual-input logic control gate circuit and a power switch device, the output pin of the Hall switch sensor connects to one input end of the dual-input logic control gate circuit, the power supply stay-on output pin of the microprocessor connects to the other input end of the dual-input logic control gate circuit, the output end of the dual-input logic control gate circuit connects to the control pin of the power switch device, the input of the power switch device connects to the power supply battery, and the output of the power switch device connects to the measurement analysis circuit of the oximeter, the said power supply control method is:
a. The battery powers the measurement analysis circuit and the display of the oximeter, i.e., the upper housing body and the lower housing body of the oximeter at the measuring end are opened, the output pin of the Hall switch sensor generates a high potential, which causes the output of the dual-input logic control gate circuit to control the power switch device into conduction;
b. Within a certain time, the microprocessor determines whether a blood oxygen signal is measured, i.e., whether a finger has ever been placed in the oximeter within a certain time;
b1. If there is a blood oxygen signal measured, the power supply will stay on, i.e., the power supply stay-on output pin of the microprocessor outputs a power supply stay-on signal;
b2. If there is no blood oxygen signal measured, a signal requiring to cut off the power supply will be sent out, i.e., the power supply stay-on output pin of the microprocessor outputs a signal of cutting off the power supply stay-on;
c. The microprocessor determines whether the upper housing body and the lower housing body at the measurement end of the oximeter housing body are still open; that is, whether the output pin of the Hall chip is still generating a high potential;
c1. If the output pin of the Hall switch sensor generates a high potential, the power supply will stay on;
c2. If the output pin of the Hall switch sensor generates a low potential, the output of the dual-input logic control gate circuit will control the power switch device into non-conduction, and the power supply will be cut off.
The dual-input logic control gate circuit consists of four dual-input NAND gates, which are the first dual-input NAND gate, the second dual-input NAND gate, the third dual-input NAND gate and the fourth dual-input NAND gate, respectively; The two input ends of the first dual-input NAND gate connect to the output pin of the Hall chip after they are shorted out, the output of the first dual-input NAND gate connects to one input of the second dual-input NAND gate, the other input of the second dual-input NAND gate connects to the output of the fourth dual-input NAND gate, the two input ends of the third-dual NAND gate connect to the output of the second dual-input NAND gate after they are shorted out, the output of the second dual-input NAND gate simultaneously connects to one input of the fourth dual-input NAND gate, the other input of the fourth dual-input NAND gate connects to the power supply stay-on output pin of the microprocessor, and the output of the third dual-input NAND gate connects to the control pin of the power switch device, the said power switch device is a P-channel power FET.
The said certain time in the embodiment is 5 seconds, i.e., when no blood oxygen signal is detected within 5 seconds, if the upper housing body and the lower housing body are closed at this point, the oximeter will shut down, and if the upper housing body and the lower housing body remain open, it indicates that the test is continuing, and the oximeter will continue operate, which avoids the repeated boot processes in continuous tests, saves the program initialization time, and improves the service efficiency of the battery and the operational efficiency of the instrument.
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The present invention relates to a digital portable pulse oximeter and battery-powered control method thereof. The automatic switching of the power supply is achieved by adding a Hall circuit, and the data displayed is allowed to always face the users by adding an acceleration sensor to the circuit. The advantageous effects of the present invention compared with the prior art are: Users can always read the data from the front side no matter which way they move. The digital portable pulse oximeter of the present invention can be automatically turned on just by inserting a finger, without having to press the switch button, and cut off the power supply by pulling out the finger, as well as judge intelligently whether to continue the measurement after the finger has been pulled out. If yes, the power supply will stay on, which reduces the energy waste and low efficiency caused by the restarting program initialization, improves the use efficiency of the battery and prolongs the battery life.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 08/441,829, filed May 16, 1995, now U.S. Pat. No. 5,661,036 issued Aug. 26, 1997; which was a continuation of Ser. No. 07/873,402, filed Apr. 24, 1992, now U.S. Pat. No. 5,424,217 issued Jun. 13, 1995; which in turn was a continuation of Ser. No. 07/275,980, filed Nov. 25, 1988, now abandoned.
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates generally to processes and apparatus for detection and measuring of chemically-bound sulfur, and more particularly, to the detection and measurement of sulfur combustion products which have been contacted by ozone to form chemiluminescent reaction products. The present invention also relates to improved processes and apparatus for enhancing the chemiluminescent detection of sulfur by the reduction of interfering compositions.
b) Discussion of the Prior Art
Numerous processes and apparatus have been devised for detecting and measuring chemical substances. Among detectors used to detect and measure fluids, whether from an independent source, or from the output of a gas chromatographic apparatus, are those using thermal conductivity, hydrogen flame ionization, electronic capture, alkaline flame ionization, and flame photometry. Of particular interest in recent years has been the sensitive and selected detection of sulfur compounds, both as a pollutant in the environment, and from other sources. The most widely utilized sulfur selective detector at the present time is the flame photometric detector (FPD). The FPD device and process is based on the fact that a hydrogen flame in the presence of air (oxygen) emits electromagnetic radiation, usually in the form of visible spectra light. In practice, a carrier fluid transporting a to-be-tested substance, for example an eluent separated from a sample by a chromatographic instrument, is mixed with an air stream (which may be oxygen enriched), and passed into a hydrogen burner, or a burner in the presence of hydrogen. The resulting mixture contains hydrogen in excess of that required for complete combustion of the oxygen present. The luminous radiation caused by this combustion impinges or is reflected through an optical filter which has been selected according to the desired radiation wavelength of the substance to be measured. Subsequently, the light from the filter passes to a light detector, such as a photomultiplier tube. The photomultiplier tube produces a current which can be detected, measured, analyzed, recorded, and so on, to indicate the substance and the amount of the substance. Such an FPD system can be used as a specific selective detector and process for sulfur in sulfur-containing substances since a specific wavelength is emitted from the formation of the molecular species of sulfur during the burning of the hydrogen flame. Such an FPD system is relatively sensitive and has been widely used, for example in pollution control and determination. However, the fundamental response of such FPD detectors to sulfur is not linear with respect to the concentration of the to be measured sulfur, and are difficult to calibrate with accuracy, especially for the measurement of low concentrations of sulfur. Another distinct problem with FPD devices is that numerous other components in the sample can interfere with accurate determination of sulfur.
Another approach to measuring sulfur-containing compounds in a fluid sample includes the use of chemiluminescence detection schemes.
There remains a need for a process and device capable of measuring sulfur compounds accurately, quickly and in the low femtogram range without being sensitive to interference of other compounds and components of the sample being tested.
SUMMARY OF THE INVENTION
In view of the foregoing, it is an object of the present invention to provide a process and device for detecting and measuring sulfur in a fluid sample, and in particular in an environmental air sample or a chromatographic eluent.
It is another object of the present invention to provide a process and device for detecting sulfur-containing compounds in a rapid and continuous manner without regard to the presence of other compounds in the sample.
A further object of the present invention is to provide a novel and improved method and apparatus for measurement of sulfur-containing compounds by chemiluminescent reaction with ozone at low pressures in such a way as to be sensitive to sulfur compounds, but insensitive to water vapor, carbon dioxide or other hydrocarbon interferences.
Accordingly, the present invention discloses and teaches a process and apparatus for the detection and measurement of bound sulfur in organic and inorganic sulfur containing compounds. The process includes admixing a fluid sample having a sulfur-containing compound with an oxygen source. This mixture is then exposed to a combustion causing heat source, such as a flame, in the presence of a reducing agent. The resulting gaseous combustion products are then vacuum extracted from the combustion site, and then directed into a darkened low pressure chamber. The combustion products in the low pressure chamber are then contacted with ozone, with the result that the sulfur combustion products are converted to chemiluminescent sulfur dioxide in an excited state. Finally, the chemiluminescence is detected and measured to provide an indication of the amount of sulfur in the fluid sample. The preferred source of oxygen is air, the preferred form of combustion heat is a flame, and the preferred form of reducing agent is hydrogen gas.
In one particular preferred embodiment of the invention, a halogenated compound is injected into the sample mixture prior to or at the time that it is subjected to combustion.
As described in greater detail below, the present invention utilizes a hydrogen-air flame to produce a combustion product of either sulfur monoxide (SO) or hydrogen sulfide (H 2 S) for subsequent reaction with ozone. It should be noted that, because of its thermal instability, ozone cannot be directly introduced at the combustion site as a feasible means of exploiting the chemiluminescent reaction of ozone with the combustion products. Various studies have shown that a significant portion of sulfur entering a flame produces sulfur monoxide. In fact, the sulfur monoxide so produced is present in the flame combustion products in concentrations which are about ten times greater than atomic sulfur, which is the substance which is normally measured by conventional FPD processes and apparatus. However, it is a possibility that the process of the present invention actually produces H 2 S, and then detects the chemiluminescent reaction of H 2 S with ozone. Nevertheless, it is believed that the principal combustion product is sulfur monoxide. Regardless of whether SO or H 2 S is produced as the combustion product, they both produce approximately the same wavelength of light during the chemiluminescent reaction with ozone.
The present invention utilizes a narrow capillary sampling probe, discussed below, which is designed to quickly draw substantially all of the combustion products to a low temperature and low pressure chamber for reaction with ozone. An important and preferred aspect of the present invention is that by lowering the pressure of the combustion product gases to a pressure within the range of about of 1 torr to about 50 torr, with approximately 10 torr preferred, the chemical combustion reactions are quenched, the possibility of condensation of water produced during combustion is eliminated, and the gas mixture of combustion products can be rapidly transferred to a light tight chamber for contact and chemical reaction with ozone. These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description, showing the contemplated novel construction, combination, and elements as herein described, and more particularly defined by the appended claims, it being understood that changes in the precise embodiments of the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate complete preferred embodiments of the present invention according to the best modes presently devised for the practical application of the principles thereof, and in which:
FIG. 1 is a schematic diagram of the apparatus of the present invention embodying the process of the present invention;
FIG. 2 is a schematic diagram of an adjustable combustion assembly utilized in the present invention; and
FIG. 3 is a graph illustrating sulfur dioxide concentration in parts per billion based on photomultiplier tube measurements of chemiluminescent light produced from samples measured using the process and apparatus of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a schematic diagram of the present version of the apparatus is illustrated therein. Referring first to a general overview of the process of the invention, a fluid sample (either gas or liquid) which contains a sulfur compound, from a source 10 is directed to a combustion site, in this case burner assembly 12. The to-be-tested sample is admixed with oxygen from a source 14 prior to reaching the combustion assembly 12. In preferred practice, oxygen is derived from an ambient air supply and is scrubbed through an activated charcoal trap 16 to remove ambient sulfur prior to admixture with the sulfur sample from 10. The sulfur/oxygen sample is then exposed to combustion causing heat in flame assembly 12 in the presence of a reducing agent from a source 18. The reducing agent is preferably hydrogen. The gaseous combustion products of the flame from the assembly 12 are immediately vacuum extracted through a flow restricted orifice to a darkened, low pressure, ambiant temperature reaction chamber 20. Ozone is continuously directed into reaction chamber 20 from an ozone generator or other ozone source 22. In reaction chamber 20 ozone is admixed and reacted with the gaseous combustion products from combustion assembly 12. This particular procedure results in the production of chemiluminescent radiation from excited SO 2 which radiation is measured by a light detector, such as a photomultiplier tube, and recorder assembly combination 24. The low pressure in the chamber 20 and at the orifice of the assembly 12 is maintained by a vacuum pump 26 which also assists in removing the products from the reaction chamber 20 after chemiluminescence.
In experimental form, the sulfur-containing sample from source 10 was a calibrated sulfur gas of known concentration. While any reducing agent may be utilized, hydrogen is preferred. While hydrogen is the preferred reducing agent, other reducing agents such as methane, butane, propane, alcohols, aldehydes, amines, ketones, olefins, and aromatic compounds may be used in the practice of the present invention.
Many of the details of reaction chamber 20 are described in greater detail in Sievers et al. U.S. Pat. No. 4,717,675. One of the differences between reaction chamber 20 of the present invention and the RCD disclosed in the referenced patent is that the measurement of sulfur dioxide chemiluminescence produced by the present invention requires a blue sensitive photomultiplier tube. The present system includes an ozone trap 28 to prevent ozone from inadvertently entering the atmosphere or the vacuum pump. Any desired or standard ozone generator 22 may be utilized in the present invention.
In one embodiment of the present invention, a Radox Chemiluminescence Detector model 270, from Sievers Research, Boulder, Colo. was obtained and then modified according to the present invention. Modifications to this commercially available unit included the replacement of the standard photomultiplier tube with a blue sensitive one (model R 268 Hamamatsu) as indicated previously, replacement of the glass window with a fused quartz window, and the addition of an optical filter (7-54 Coming Glass Works, Coming, N.Y.). The optical filter transmits between about 240 and about 410 nanometers with a peak transmittance of about 82% at 320 nm. In addition, the reaction cell was modified to accommodate greater sample flow rates. Larger flow rates were achieved by replacement of the standard 25 liter/minute vacuum pump with a 300 liter/minute model (Model 1012, Alcatel, France). A high capacity ozone generator was utilized which could produce nearly ten times more ozone, 100 cm 3 /minute, than the ozone generator in the standard RCD reaction chamber. Dilution air used in the dynamic dilution calibration system was metered by a rotometer and calibration standards of sulfur gases as well as hydrogen were metered with mass flow meters.
Dilution air for the ambient air supply 14 was obtained from the laboratory bench, but first passed through the activated charcoal absorbent bed 16 as previously indicated. All tubing between the sample orifice and the reaction chamber reaction cell was coated with halocarbon wax (Series 1200, Halocarbon Products, Hackensack, N.J.) to minimize loss of the SO to wall reactions. Oxygen supplied to the ozone generator and hydrogen were standard grade and no provisions were made to remove contaminants from the gases. The sample orifice was empirically sized to provide a total flow of 500 actual cm 3 /min in a reaction cell pressure of 9-10 torr, as discussed below.
FIG. 2 illustrates a preferred arrangement for burner assembly 12. More specifically, assembly 12 is of quartz and is built to contain a combustion heat source in the form of a diffusion flame. The assembly 12 includes a quartz housing 30 with a sample/air intake vent 32. Hydrogen or another reducing agent is injected through an injection vent 34 which projects into the housing 30. The terminal end 36 of the vent tube 34 is the site of the diffusion flame. A quartz probe 38 terminating in an orifice 40 projects within the housing 30. The flame resides between the terminal end of the probe 38 and the end 36 of the tube 34. The probe 38 mounted to a sliding seal 42, permits the distance between the end of the probe 38 and the end 36 of tube 34 to be varied. In this manner, the residence time of the sample in the burner may be varied from 1-40 ms. In preferred form, the residence time of the sample in the burner is 4 ms/cm. In alternate form, the flame from an FID (flame ionization detector) may also be used as a flame source for the present invention. Moreover, any type of flame source may be utilized to react the sample with oxygen and reducing agents to generate the product gases for subsequent reaction with ozone and chemiluminescence from excited sulfur dioxide.
Preliminary testing of the present invention for sulfur uses the detector in a real-time analysis mode. It is found to be important that the post-flame pneumatic system be maintained at as low a pressure as possible for a variety of reasons. First, the intensity of the chemiluminescent reaction was found to be inversely proportional to pressure with a half-quenching pressure of about 0.02 torr. In addition, the gaseous sample stream produced from the flame is about 25% water vapor requiring that the pneumatic system be maintained well below the vapor pressure of water (about 50 torr) to prevent condensation. Such condensation would dramatically interfere with the chemiluminescent aspects of the invention. Also, the post-flame reactions are effectively quenched at low pressure allowing the SO radical to be transported to the reaction chamber. All data presented below are based on a sample air flow of 500 cm 3 /min, a cell pressure of 50 torr, and 6% O 3 in 100 cm 3 in 100 cm 3 of O 2 . The addition of the UV filter in the reaction chamber decreased a high baseline signal to less than 0.5% of full scale. Typical parameters for the example shown below include 300 ml/min of hydrocarbon reducing agent, 500 ml/min of air and sample into the flame, and a system pressure of approximately 10 torr in addition to an oxygen flow of approximately 100 ml/min.
Equivalence ratio is defined as the ratio of the actual hydrogen flow rate to the hydrogen flow rate needed for stoichiometric combustion. From test results utilized in the process of the present invention, the sensitivity of the present invention to sulfur dioxide and all other sulfur containing gases tested is a function of the equivalence ratio. It was found that the optimal equivalence ratio is between 1.4-1.6. This optimum equivalence ratio is independent of the sample residence time in the flame, and thus the sample orifice position. It is believed that the reason for the sharp optimum equivalence ratio is because there must be sufficient hydrogen to react with molecular oxygen thus reducing the rate at which SO is converted to SO 2 , without reducing the flame temperature to the point that SO is not formed.
With respect to the flame residence time, it was determined that the optimum flame residence time is approximately 2.5 ms. The sensitivity as a function of the flame residence time decreases very rapidly at shorter flame residence times probably because the combustion is incomplete and SO (or H 2 S) is not formed. At longer residence times, the signal reaches a constant value at the SO equilibrium concentration, but the background noise increases due to a less stable flame.
With respect to the effect of ozone flow and concentration, a standard reaction chamber ozone generator was initially used. The ozone concentration produced with oxygen is twice that produced using dry air, and a corresponding improvement in sensitivity was observed. As a result, the apparatus of the present invention was switched to the larger ozone generator thereby increasing ozone concentration by ten times. This showed an increase in sensitivity by a factor of 2. The ozone flow rate at which the sensitivity is optimum corresponds to 6 ml ozone per minute in 100 cm 3 /min of oxygen. The flame produced a large amount of NO which also reacts with ozone thus requiring an unusually large amount of ozone. However, the NO reaction did not in any way interfere with the chemiluminescence of sulfur dioxide and the measurement thereof, because it occurs at a longer wavelength not passed by the optical filter.
Two common interfering species for the previous flame photometric detector processes and apparatus operated in real time mode are carbon dioxide and water vapor.
The process and device of the present invention demonstrated no effect on either the baseline signal or the response to a given concentration of SO 2 for water vapor between 0.4% and 3.0%, which is equivalent of 12-83% relative humidity at 23° C. It also demonstrated no effect of carbon dioxide concentration between 350 ppmv and 1700 ppmv. In chromatographic analyses, two compounds which commonly coelute are methylethyl sulfide (MES) and hexane. The hexane enhances the sulfur signal at low sulfur concentration and quenches the sulfur signal at high sulfur concentration. Tests utilizing the present invention for various flame residence times demonstrated that it is possible to eliminate any interference from hexane entirely by adjusting the flame residence time. In another test, the response to sulfur dioxide as a function of heptene concentration at a fixed flame residence time of 7.5 ms was studied. Heptene causes a large signal in other sulfur monitors. The heptene was responsible for an enhancement of the SO 2 signal. The present invention did not have any detectable response to clean air, that is with no sulfur, with concentrations of either hexane or heptene up to 4000 ppmv. Apparently, the flame chemistry is perturbed by the hydrocarbon in such a way that SO production is affected to a minor extent. It should be pointed out that the effect of the present invention's response from hydrocarbons is 10 4 -10 5 less than that reported for FPD devices presently utilized.
EXAMPLE I
The process and system illustrated in FIG. 1 and discussed above was used intermittently for approximately 30 days. The standard parameters discussed above were applied. During this time, the baseline signal was very stable and good sensitivity to sulfur dioxide was obtained. The results of these tests are illustrated in FIG. 3 showing a consistent and good sensitivity to sulfur dioxide concentration.
EXAMPLE II
It was observed that after nearly two months of working with the process and device of the present invention as described in EXAMPLE I, the baseline signal would start to increase continuously. In spite of the increase in baseline, it was determined without question that the process and apparatus of the present invention had a sensitive response to each of the sulfur compounds tested, that is methyl ethyl sulfide, ethyl mercaptan, dimethyl sulfide, sulfur dioxide, sulfur hexafluoride and hydrogen sulfide. However, with the increase in baseline quantification of the response became impossible. This background chemiluminescence increased when the ozone generator was turned off so that only oxygen was reacting with sample gases and disappeared completely when the oxygen flow was stopped. The absolute intensity of the background signal was not sufficiently intense to allow spectral analysis. Consequently, the results were that the chemiluminescence continued even after the flow of sulfur compounds was stopped.
The following observations were made when the baseline was too high and irregular to allow analytical use of the process and device of the present invention:
1) The baseline signal increased when the power to the ozone generator was turned off.
2) The baseline signal decreased to zero if the oxygen flow was stopped completely.
3) The sensitivity to sulfur dioxide decreased if the baseline was high compared to the sensitivity when the baseline was at its normal low level.
4) The magnitude of the baseline signal was affected by changing the hydrogen flow rate. The highest baseline signal was observed with the same hydrogen flow rate that produced the most sensitive response to sulfur.
5) The baseline signal could be decreased for a period of time to a very low and acceptable value by momentary injection of any halogenated compound into the flame.
6) Replacement of the quartz sample orifice with a newly fabricated one did not affect the baseline signal.
Since it was found that the addition of a small amount of a halogenated compound to the flame would eliminate the baseline drift without affecting the sensitivity to sulfur, it is theorized that the reactive species responsible for the background luminescence is scavenged by the halogens. The chemical species which produces the chemiluminescence with oxygen in the flame is unknown. Consequently, in order to maintain a low baseline over a long period of use of the process and apparatus of the present invention, one embodiment of the present invention introduces a halogenated compound, such as fluorocarbon 12, fluorocarbon 11, or carbon tetrachloride to the sample at point 46 illustrated in FIG. 1, introducing the halogenated compounds into the oxygen and sample at or immediately before the flame, or in the hydrogen flow. With the addition of fluorocarbon or other halogenated compound, the baseline has been observed to be low and stable. The observed change was from a maximum to a minimum the equivalent of less than 0.2 ppbv sulfur during 75 hours of continuous observation.
EXAMPLE III
In an attempt to remedy the problem outlined in EXAMPLE II above, several different materials were used as the flow system walls in the belief that one would react with and thus remove the species causing the high baseline signal. All six materials tested provided a short period of acceptable baseline signal. The materials and times tested are listed below in TABLE I.
______________________________________MATERIALS TIME______________________________________halocarbon wax 18 hourshalocarbon oil 7 hoursparaffin wax 10 hoursaluminum (type 6061-t6) 3 hoursstainless steel (type 304) 6 hoursTeflon 0 hours______________________________________
When it became apparent that the switching of flow system materials would provide only temporary reductions in baseline, a new approach was pursued.
EXAMPLE IV
The new approach discussed in EXAMPLE III and discussed also in part above, involved the addition of a halogenated compound on a continuous basis. A continuous flow of 0.45 cm 3 /min of CF 2 Cl 2 was introduced into the sample air producing a concentration of hundreds of ppm. The baseline was observed to be stable for indefinite periods with the chlorofluorocarbon addition. Two other chlorofluorocarbon concentrations have been used, 40 and 180 ppmv, and both work equally well for the reduction of the baseline. In addition, neither of the two chlorofluorocarbon concentrations affected, either positively or negatively, the sensitivity of the process and apparatus of the present invention to sulfur compounds. With the addition of 40 ppm chlorofluorocarbon, it was possible to quantify the response to different sulfur compounds. These results indicated that the sensitivity to the sulfur compounds listed above in EXAMPLE II as well as H 2 S are all equal. It should be emphasized that the chlorofluorocarbon could be added to the flame, either into the air stream or into the hydrogen flow with the same result.
EXAMPLE V
The present invention has a variety of system applications. Reconfiguration of the system in only minor details provides different uses for the device and process of the invention. In this example, the addition of a chromatographic effluent into point A, that is 46 of FIG. 1, provides species specific detection of sulfur and removal of the activated charcoal trap (16) provide a means of monitoring concentrations of total sulfur in ambient air.
The process and apparatus of the present invention for the detection and monitoring of sulfur has been shown to be a very sensitive, selective and linear detector operated in the real-time mode. The present invention provides detection limits at similar levels reported for flame photometric detectors but at response times which are at least 30 times faster. The present invention does not suffer from the interference problems experienced by the flame photometric detectors of the prior art from water vapor or carbon dioxide and four to five orders of magnitude less for hydrocarbons. The present invention also provides uniform response to different sulfur compounds which greatly enhances its utility as a gas chromatographic detector. Finally, the present invention provides much more accurate and faster sulfur detection capability than either flame photometric detectors known previously hereto or prior detection devices which are based on chemiluminescence of reaction of ozone with the air sample directly.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not specifically restrictive, and the invention is not to be limited to the details given herein but may be modified within the scope of the appended claims as limited by the prior art.
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A process and apparatus are disclosed for the detection and measurement of sulfur in both organic and inorganic sulfur-containing compounds. The process includes admixing a sample including a sulfur-containing compound with oxygen, and then exposing the mixture to a source of combustion causing heat in the presence of a combustion supporting reducing agent at a combustion site. The resulting gaseous combustion products are vacuum extracted from the combustion site, and then directed into a darkened low pressure chamber. The combustion products in the low pressure chamber are then contacted with ozone, with the result that the sulfur combustion products are converted to chemiluminescent sulfur dioxide. The emitted chemiluminescence is then detected, and may be measured to provide a quantitative indication of the amount of sulfur in the original sample. The preferred source of oxygen is air, the preferred form of combustion heat is a flame, and the preferred form of reducing agent is hydrogen gas.
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FIELD OF THE INVENTION
[0001] The invention relates to an apparatus and method for reducing polymer deposition on a substrate and substrate support, and more particularly, the invention relates to the adjustment of a gap between a substrate holder and a substrate to reduce polymer deposition on exposed surfaces of the substrate holder and bottom surfaces of the substrate.
DESCRIPTION OF THE RELATED ART
[0002] Vacuum processing chambers are generally used for chemical vapor depositing (CVD) and etching of materials on substrates by supplying process gas to the vacuum chamber and application of an RF field to the gas. Examples of parallel plate, inductively coupled plasma (TCP™, also called ICP), and electron-cyclotron resonance (ECR) reactors are disclosed in commonly owned U.S. Pat. Nos. 4,340,462; 4,948,458; and 5,200,232. The substrates are held in place within the vacuum chamber during processing by substrate holders. Conventional substrate holders include mechanical clamps and electrostatic clamps (ESC). Examples of mechanical clamps and ESC substrate holders are provided in commonly owned U.S. Pat. No. 5,262,029 and commonly owned U.S. Pat. No. 5,671,116. Substrate holders in the form of an electrode can supply radio frequency (RF) power into the chamber, as disclosed in U.S. Pat. No. 4,579,618.
[0003] Substrates which are etched in an oxide etching process generally include an underlayer, an oxide layer which is to be etched, and a photoresist layer formed on top of the oxide layer. The oxide layer may be one of SiO 2 , BPSG, PSG, or other oxide material. The underlayer may be Si, TiN, suicide, or other underlying layer or substrate material. During processing of substrates, unwanted polymer deposition on the surfaces of the chamber can occur. For instance, when the chamber heats up to above 80° C. during oxide etching, a reaction can occur wherein CF 3 forms CF 2 and HF. The formation of CF 2 leads to an increase in polymer deposition on surfaces within the chamber.
[0004] During etching of a substrate such as a semiconductor wafer in a plasma reactor, the polymer can build up on the cooled, exposed surfaces of the chamber including exposed surfaces of a substrate support such as an electrostatic chuck and other surfaces such as a dielectric annular cap/focus ring surrounding the substrate support. This buildup may cause problems if it flakes off and is carried onto the top surface of the electrostatic chuck. These contaminants on the top surface of the chuck can prevent the chuck from operating properly to hold the wafer securely. In addition, the contaminants can allow helium which is supplied under the wafer as a cooling medium to leak from beneath the wafer and reduce the wafer cooling. The contaminants can also be deposited on and adversely affect the wafer itself.
[0005] The buildup of polymer can be removed by a cleaning step performed between the processing of successive wafers. Generally, cleaning can be performed by injecting oxygen into the chamber, striking a plasma and reacting the oxygen with the deposited polymer to achieve an aggressive oxygen clean of the processing chamber.
[0006] The aggressive oxygen cleaning of the processing chamber is undesirable because it adds to the wafer cycle time, reducing through-put of the system. In addition, the aggressive oxygen clean will shorten the lives of members within the processing chamber due to ion bombardment of these members. As such, it would be desirable if substrate processing could be carried out without a need for the aggressive oxygen cleaning step to thereby shorten cycle time and extend the life of chamber components.
[0007] One example of a vacuum processing chamber 10 is illustrated in FIG. 1. The vacuum processing chamber 10 includes a substrate holder 12 including an electrode providing an RF bias to a substrate supported thereon. The substrate holder 12 includes an electrostatic clamp 14 for clamping the substrate. The substrate which is placed on the electrostatic clamp 14 is preferably cooled by helium backcooling (not shown) provided between the substrate and the electrostatic clamp. A ring 16 surrounds the electrostatic clamp 14 . The ring 16 may be a ceramic focus ring; a combination of a focus ring, coupling ring, and edge ring; or another combination of rings.
[0008] The vacuum processing chamber 10 includes a source of energy for maintaining a high density (e.g. 10 11 -10 12 ions/cm 3 ) plasma in the chamber such as an antenna 18 (such as a planar spiral coil or other suitable design) which is positioned above the chamber and powered by a suitable RF source. A suitable RF impedance matching circuit, inductively couples RF into the chamber 10 so as to provide a high density plasma. The chamber 10 also includes a suitable vacuum pumping apparatus for maintaining the interior of the chamber at a desired pressure (e.g. below 50 mTorr, typically 1-20 mTorr). A dielectric window 20 (such as a uniformly thick and planar sheet of quartz, alumina, silicon nitride, etc.) is provided between the antenna 18 and the interior of the processing chamber 10 and forms the vacuum chamber wall at the top of the processing chamber 10 . A dielectric gas distribution plate, commonly called a showerhead 22 , may be provided beneath the window 20 and includes a plurality of openings such as circular holes (not shown) for delivering process gas supplied by a gas supply to the processing chamber 10 . However, the gas distribution plate 22 can be omitted and process gas can be supplied to the chamber by other arrangements such as gas rings, etc.
[0009] One area in which deposits of polymer can occur in a processing chamber is a narrow gap 30 between the wafer supported on the electrostatic chuck 14 and the surrounding ring(s) 16 . Specifically, a gap 30 is provided beneath the edge of the wafer which overhangs the surrounding ring. This gap 30 allows for manufacturing tolerances, thermal expansion and wear of the parts. However, process gas and volatile byproducts within the chamber 10 may migrate into the gap 30 and cause undesirable polymer deposits in the gap and on the underside edge of the wafer which may flake off and cause contamination of the wafer and/or chamber.
[0010] [0010]FIG. 2 is an enlarged cross sectional view of an outer portion of an electrostatic chuck 14 ′ and surrounded rings including a focus ring 16 , a coupling ring 40 , and a hot edge ring 42 .
[0011] As shown in the enlarged view of FIG. 3, when a substrate S in the form of a semiconductor wafer is positioned on the electrostatic chuck 14 ′ and held in place by a suitable electrostatic clamping force a small vertical gap 30 ′ is provided between an overhanging edge of the substrate S and a groove 44 provided in the edge of the hot edge ring 42 . This vertical clearance gap 30 ′ is designed to prevent the overhanging edge of the substrate S from being lifted and thereby avoid a reduction in clamping force applied by the electrostatic chuck 14 ′. However, this additional vertical clearance gap 30 ′ provides additional opportunity for polymer buildup which may flake off and contaminate the substrate S or the electrostatic chuck 14 ′.
[0012] Thus, it would be desirable to reduce the vertical gap 30 ′ between the hot edge ring 42 or other surrounding ring and the overhanging substrate edge.
SUMMARY OF THE INVENTION
[0013] The present invention relates to an apparatus for adjusting a gap between a ring surrounding substrate support and a substrate.
[0014] In accordance with one aspect of the invention the plasma processing apparatus comprises a processing chamber, a power source which energizes process gas in an interior of the processing chamber into a plasma state for processing a substrate, a substrate support which supports a substrate within the interior of the processing chamber, the substrate support having an upper surface, an upper ring surrounding the substrate support, the upper ring having a portion extending under a substrate when the substrate is located on the substrate support, and a coupling ring surrounding the substrate support, the coupling ring having a first ring rotatable with respect to a second ring to adjust height of the coupling ring and adjust a gap between the upper ring and the substrate.
[0015] In accordance with another aspect of the invention the plasma processing apparatus comprises a processing chamber, a process gas which energizes process gas in an interior of the processing chamber into a plasma state for processing a substrate, a substrate support which supports a substrate within the interior of the processing chamber, the substrate support having an upper surface, an upper ring surrounding the substrate support, the upper ring having a portion extending under a substrate when the substrate is located on the substrate support, and a coupling ring surrounding the substrate support, the coupling ring having a first ring rotatable with respect to a second ring to adjust height of the coupling ring and adjust a gap between the upper ring and the substrate.
[0016] In accordance with a further aspect of the invention the method of reducing polymer deposition on a substrate support in a plasma processing system comprises providing an adjustment mechanism for adjusting a gap between a substrate and a surrounding ring in a plasma processing apparatus, and adjusting the gap between the substrate and the surrounding ring by rotating a first ring with respect to a second ring of the adjustment mechanism.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0017] The invention will now be described in greater detail with reference to the preferred embodiments illustrated in the accompanying drawings, in which like elements bear like reference numerals, and wherein:
[0018] [0018]FIG. 1 is a cross sectional view of a vacuum processing chamber;
[0019] [0019]FIG. 2 is an enlarged cross sectional view of a portion of FIG. 1 showing the electrostatic chuck and surrounding rings;
[0020] [0020]FIG. 3 is an enlarged cross sectional view of portion A of FIG. 2;
[0021] [0021]FIG. 4 is an enlarged cross sectional view of a portion of a vacuum processing chamber according to the present invention including an adjustable coupling ring;
[0022] [0022]FIG. 5 is an exploded schematic prospective view of the adjustable coupling ring of FIG. 4; and
[0023] [0023]FIG. 6 is an enlarged cross sectional view of a portion of an electrostatic chuck and focus ring showing a gap between the focus ring and substrate.
DETAILED DESCRIPTION OF THE INVENTION
[0024] A portion of a substrate support for a vacuum processing chamber according to one embodiment of the present invention is illustrated in FIG. 4. The substrate support 100 illustrated in FIG. 1 includes an electrostatic chuck 102 , a focus ring 104 , a coupling ring 106 , and a hot edge ring 108 .
[0025] As is well known to those familiar with the plasma processing art, the rings surrounding the electrostatic chuck including the focus ring 104 , coupling ring 106 , and hot edge ring 108 help focus the ions from the RF induced plasma region on the surface of the substrate to improve process uniformity, particularly at the edge of the substrate. This is because when RF power is supplied to substrate holding chuck 102 , equipotential field lines are set up over substrate and bottom electrode. These field lines are not static but change during the RF cycle. The time averaged field results in the bulk plasma being positive and the surface of the substrate and electrostatic chuck negative. Due to geometry factors, the field lines are not uniform at the edge of the substrate. The focus, coupling, and hot edge rings help direct the bulk of the RF coupling through substrate to the overlying plasma by acting as a capacitor between the plasma and the powered electrode (e.g., RF-powered chuck ).
[0026] The hot edge ring 108 overlays an adjustable RF coupling ring 106 . The hot edge ring 108 is a sacrificial edge ring surrounding the electrostatic chuck 102 . The hot edge ring 108 is a replaceable component which tends to become hot during processing of a substrate and thus is referred to as a hot edge ring. The hot edge ring 180 may be made from conductive electrode materials such as SiC and silicon or from dielectric materials such as quartz. By changing the edge ring material, the degree of coupling through the plasma can be tailored to provide a desired localized “edge” etch rate at the outer portion of a substrate being processed. SiC, having a lower capacitive impedance, will generally produce a faster edge etch rate than silicon. Quartz and other dielectrics will have a lesser effect on the edge etch rate.
[0027] In the described embodiment a gap 130 , shown in FIG. 6, is formed between an over hanging edge of the substrate S and the silicon hot edge ring 108 . The gap 130 has a vertical dimension d controlled by the adjustable RF coupling ring 106 . The adjustable RF coupling ring 106 is capable of controlling the vertical dimension d of the gap by moving the silicon hot edge ring 108 in a vertical direction as appropriate. It should be noted that vertical direction is any direction substantially parallel to a Y axis, as shown in FIGS. 1 and 6.
[0028] In accordance with one embodiment of the invention, the adjustable RF coupling ring 106 moveably supports the silicon hot edge ring 108 . The adjustable RF coupling ring 106 provides mechanical support for the silicon hot edge ring 108 as well as the capability to control the gap distance d to within a specified range. In one aspect of the invention, the adjustable RF coupling ring 106 is capable of forming the gap with an associated gap distance d ranging between approximately 0.5 mils to less than 6 mils.
[0029] In the described embodiment, the adjustable RF coupling ring 106 includes two rings 110 , 112 as shown in FIG. 5. The first ring 110 or top ring includes three projections 114 extending from the ring in a direction parallel to a Y axis of the ring. The second ring 112 or bottom ring includes three sets of a plurality of graduated steps 116 around the circumference of the ring. Rotation of the first ring 110 clockwise with respect to the second ring 112 decreases an overall vertical height of the coupling ring 106 and adjusts the gap between the substrate and the hot edge ring 108 .
[0030] In the described embodiment, the adjustable coupling ring 106 preferably includes graduated steps 116 that vary in height increments of about 0.0001-0.01 inches and preferably about 0.001 inches. Although the illustrated embodiment includes six graduated steps 116 in each of the three sets of steps, other numbers of steps may also be used depending on the amount of adjustment and graduation of adjustment desired. According to another embodiment twelve graduated steps 116 are provided for twelve adjustment heights.
[0031] In the described embodiment, the top ring 110 of an adjustable coupling ring 106 includes the projections 114 with a height which is equal to approximately the total height of all the steps 116 in one of the three sets of plurality of graduated steps. In a preferred embodiment, the projections 114 have a height of about 0.012 inches. In the described embodiment, the adjustable coupling ring 106 can be formed of quartz.
[0032] The adjustable RF coupling ring 106 according to the present invention, allows the precise adjustment of the gap 130 between the substrate S and the hot edge ring 108 in a plurality of individual steps. The coupling ring 106 allows an operator to readjust the coupling ring at any time between processing of substrates or during set up of the vacuum processing chamber. The RF coupling ring 106 also ensures that the hot edge ring 108 is adjusted evenly on all sides of the substrate and that a top surface of the coupling ring remains substantially horizontal.
[0033] The adjustable RF coupling ring 106 may be installed in new vacuum processing chambers or used to retrofit existing vacuum processing chambers to provide adjustability of the hot edge ring 108 .
[0034] A process for installing and adjusting the adjustable RF coupling ring 106 is easily implemented as follows. The bottom ring 112 of the coupling ring 106 is placed on the step of the electrostatic chuck 102 with the plurality of graduated steps 116 facing upward. The top ring 110 is then placed onto the bottom ring 112 with the three projections 114 each aligned on the highest of the graduated steps. The hot edge ring 108 is then placed on top of the assembled coupling ring 106 and the gap is measured with a measuring device. One example of a measuring device is a vertical mount dial indicator which is placed on the substrate holding chuck 102 and measures a vertical distance from the top of the chuck to the top of the edge of the hot edge ring 108 . Preferably, the gap 130 is measured at 90 degrees apart around the electrostatic chuck. The measurement is taken at a location on the hot edge ring 108 close to the electrostatic chuck 102 . Due to deterioration or wear of the hot edge ring, just outside the edge of the substrate, the area of the hot edge ring 108 closest to the chuck 102 should be the highest location in the hot edge ring groove. The measurement will generally indicate that the hot edge ring 108 is higher than the electrostatic chuck 102 and that the hot edge ring needs to be adjusted downward. The hot edge ring 108 is then removed. The coupling ring 106 is then adjusted by rotating the top ring 110 clockwise and thus reducing the height of the coupling ring. The hot edge ring 18 is then replaced and the adjustment is then repeated until a minimum gap distance d is achieved.
[0035] According to one preferred embodiment of the invention, the rings 110 and 112 of the coupling ring 106 include a locking feature (not shown) which locks the rings in an aligned radial position. One example of a locking mechanism includes an detent on the top ring 110 which interlocks with grooves on each step of the bottom coupling ring 112 .
[0036] It should be appreciated that in a specific system, the specific shape of the focus ring 104 , the coupling ring 106 , and the hot edge ring 108 may vary depending on the arrangement of chuck 102 , substrate and/or others. Therefore, the exact shape of the rings surrounding the chuck in FIGS. 4 - 6 are shown for illustration purposes only and are not limiting in any way. Although the invention has been illustrated with a coupling ring arranged to adjust a hot edge ring, other rings may also be adjusted using the coupling ring.
[0037] While the invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention.
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An adjustable RF coupling ring is capable of reducing a vertical gap between a substrate and a hot edge ring in a vacuum processing chamber. The reduction of the gap reduces polymer deposits on the substrate and electrostatic chuck and improves wafer processing.
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This is a continuation of application Ser. No. 08/630,236, filed Apr. 10, 1996 which is a continuation-in-part of U.S. Ser. No. 08/451,606, filed May 26, 1995, both now abandoned.
BACKGROUND OF THE INVENTION
Inorganic adsorbent materials, such as molecular sieves, zeolites, etc., have long been used to remove constituents from (gaseous and/or liquid) fluids. Zeolites such as zeolites A and X are widely used in desiccating and gas treatment applications.
The use of adsorbent materials in the form of a free flowing particulate (e.g. beads) well known. Such beads typically comprise the adsorbent material in combination with a binder. While inorganic binders are most often used, the use of organic binders in free flowing beads is also known and is of growing interest. Where an organic binder is used, it is naturally desired to minimize the organic content of the bead while maintaining sufficient physical integrity in the bead.
In other instances, the adsorbent may be placed in an organic matrix which is then applied to a surface. For example, in the window spacer structures disclosed in U.S. Pat. Nos. 5,177,916 and 5,255,481, the adsorbent material is loaded into an organic matrix which is then adhered to the spacer. The adsorbent is typically incorporated into the organic matrix by mechanical mixing while the organic matrix material is in a very soft or molten state. It is generally desirable to incorporate as much of the adsorbent as possible per unit of organic matrix so as to enhance the adsorption performance of the adsorbent/organic matrix composite as well as to reduce the cost of the composite in situations where the organic material is more expensive than the adsorbent. Unfortunately, the amount of adsorbent which can be loaded into the composite is often limited by viscosity buildup which occurs during incorporation of the adsorbent as well as by a loss of workability and/or physical integrity in the resulting composite where the composite is applied to a substrate as in the above mentioned window spacer structures.
The organic binder level requirement and/or viscosity buildup associated with commercial adsorbent molecular sieves is generally assumed to be constant and unalterable. While it might be possible to increase the adsorbent loading by developing specialized organic materials or additives, these alternatives are typically expensive. Thus, there is a need for new ways of minimizing organic content adsorbent/organic matrix (binder) compositions, yet with minimal sacrifice of physical integrity and/or workability in the resulting composite.
SUMMARY OF THE INVENTION
The invention overcomes the disadvantages of known inorganic adsorbent/organic matrix (binder) composites by the use of adsorbent molecular sieve particles wherein at least a substantial portion of particles are single (and/or twinned) crystal particles. The use of single crystal adsorbent particles allows higher adsorbent loading to be achieved with the resulting improved adsorption performance while maintaining or improving the physical integrity and/or workability of the resulting composite.
In one aspect, the invention encompasses compositions comprising molecular sieve particles in an organic matrix (binder) wherein at least a portion of the molecular sieve particles are in the form of single and/or twinned crystals. The molecular sieve particles are preferably zeolites. Preferably, the organic matrix is a thermoplastic organic material such as a so-called "hot melt" adhesive. The adsorbent/organic matrix compositions are preferably suitable for use in insulating glass window spacer applications.
In a further aspect, the invention encompasses free flowing bead compositions comprising molecular sieve particles in an organic matrix (binder) wherein at least a portion of the molecular sieve particles are in the form of single and/or twinned crystals.
These and other aspects of the invention will be described in further detail below.
DETAILED DESCRIPTION OF THE INVENTION
The invention encompasses the concept that the loading of molecular sieve adsorbents (especially zeolite desiccants) in an organic matrix (binder) can be increased from loadings possible with commercial molecular sieves conventionally used for desiccant applications. This result is made possible by the use of molecular sieves which contain a substantial amount of single and/or twinned crystal particles compared to molecular sieves normally used in desiccant applications.
The nature of most crystalline molecular sieve particles which are commercially available for desiccant applications is that a large portion (if not all) of the particles are polycrystalline particles wherein the crystals are intergrown. In comparison, the crystalline molecular sieves used in the invention comprise a substantial portion of single crystal and/or twinned crystal particles. Preferably, the crystalline molecular sieve component used in the invention compositions contains at least about 50% of single and/or twinned crystal particles. Most preferably, the crystalline molecular sieve component used in the invention compositions consists essentially of single and/or twinned crystal particles.
While the degree of single and/or twinned crystal character of molecular sieve particles can be determined by microscopic techniques, a "wetting" test has been developed to distinguish crystalline molecular sieves which have suitable single and/or twinned crystal morphology. In the wetting test, a 10 gram sample of crystalline molecular sieve powder (activated at 315° C. for 2 hours) is placed into a ceramic mortar. Water is then added dropwise to the powder while mixing the powder with a pestle. The water addition and mixing is continued until a rather distinct thixotropic endpoint is reached at which a slight shear applied to the damp powder (achieved by slowly turning the pestle on the surface of the powder) results in fluid flow of the mixture. The wetting test value is the mass of water (grams) required to reach the thixotropic endpoint. Wetting test values less than about 8.5 correspond to molecular sieves having mostly single and/or twinned crystal particles whereas values of 9 or more correspond to molecular sieves containing mostly intergrown polycrystalline particles.
The amount of the molecular sieve adsorbent incorporated into the organic matrix can vary depending on the desired desiccating capacity, the rheological properties of the specific organic matrix and the intended end application. For free flowing beads, the amount of adsorbent is preferably about 70-95 wt. % of the total composition, more preferably about 75-90 wt. %. For non-bead applications (e.g. adhesive applications), a loading of about 35-65 wt. % activated crystalline molecular sieve is preferred, more preferably about 40-60 wt. %.
The molecular sieves useful as the single and/or twinned crystal molecular sieves in the invention are preferably zeolites. Most preferably, the molecular sieves are selected from the group consisting of zeolite A (including varieties and modifications thereof such as zeolite 3A), zeolite X (including varieties and modifications thereof such as zeolite 13X), and mixtures thereof. While zeolites A and X have been used in desiccant/adsorbent applications previously, the A and X powders used for such purposes were polycrystalline in nature and have wetting test values in excess of 9. If desired, minor amounts of amorphous molecular sieves and/or polycrystalline molecular sieves having wetting test values outside the desired range may also be employed as an admixture. Preferably, such amorphous and/or polycrystalline molecular sieves represent less than 50 wt. % of the total molecular sieve component, more preferably less than 25 wt. %, most preferably less than 10 wt. %. Where zeolite 3A is used, preferably it has a high potassium content as described in U.S. patent application Ser. No. 08/451,629, filed on May 26, 1995.
The organic matrix (binder) component preferably contains an organic resin useful in desiccant/organic matrix (binder) composite applications. Examples of suitable matrix resins are described in U.S. Pat. Nos. 5,177,916 and 5,255,481. The invention is especially useful where the organic matrix contains a thermoplastic resin such as a hot melt adhesive. Preferred thermoplastic resins have a Brookfield viscosity (@ 190° C--ASTM D 3236) of about 2000-6000 cP (2.0-6.0 Pa-sec), more preferably about 3000-4000 cP. An alternate characteristic of preferable resins is that they have a viscosity at 124° C. of about 4000-8000 cP. Further alternative characteristics of preferable resins are that they have a melt flow index of about 100-200 and a softening point of at least 90° C. A preferred classes of resins are olefin copolymers and terpolymers such as described in U.S. patent application Ser. No. 304,312 filed on Sep. 13, 1994 the disclosure of which is incorporated herein by reference. Other suitable thermoplastic resins are disclosed in U.S. Pat. No. 5,503,884, the disclosure of which is incorporated herein by reference. Where the desiccant/matrix composition is to be formed into free flowing beads or granules, resins such as disclosed in U.S. Pat. Nos. 4,295,994; 4,337,171; 4,414,111; 4,920,090; and 5,120,600, the disclosures of which are incorporated herein by reference.
The organic matrix component may contain other additives such as tackifiers, antioxidants, coloring agents, etc. depending on the intended end use. The amount of tackifier use is preferably about 0-20 wt. % based on the total weight of the organic matrix component, more preferably about 5-15 wt. %. Polyisobutylene is a preferred tackifier. Depending on the particular end use, components other than the molecular sieve component and the organic matrix component may be present in the composition, however, preferably the compositions of the invention consist essentially of the molecular sieve component and the organic matrix component.
As noted above, most commercially available molecular sieves marketed for desiccant/adsorbent applications are predominantly polycrystalline in character such that they have a wetting test value of 9 or more.
The zeolite molecular sieves especially useful in the invention compositions (i.e. with wet test values <8.5) can be prepared under specific manufacturing conditions corresponding to those used to make certain detergent zeolites such as can be found in U.S. Pat. No. 4,371,510 or British Patent Specification 1,563,467. Where a 3A zeolite is desired, an NaA zeolite prepared in the manner described is simply exchanged with potassium using a conventional ion exchange technique such as disclosed in U.S. Pat. No. 2,882,243.
The compositions of the invention may be formed by any conventional blending method. Preferably, the ingredients of the organic matrix are combined together before addition of the adsorbent component. Where the organic resin used possesses thermoplastic or hot melt characteristics, the mixing is preferably conducted with heating (e.g., about 180°-310° F.) to reduce the viscosity of the organic resin. The single crystal adsorbent component is preferably thermally activated using conditions known in the art before it is combined with the organic matrix. Where multiple adsorbents are used, preferably the adsorbents are physically blended with each other before addition to the heated matrix.
Where the desiccant/matrix composition is to be formed into free flowing beads or granules, the techniques disclosed in U.S. Pat. Nos. 4,295,994; 4,337,171; 4,414,111; 4,920,090; and 5,120,600 or any known technique may be used to form the beads or granules.
Once the composition is formed, it can be applied to a desired substrate by any conventional technique or otherwise used as desired.
The aspects of invention are further illustrated by the following examples.
EXAMPLE 1
Zeolite 3A particles were prepared in accordance with the above mentioned patents which had a wet test value of 8.0 (Sample A). For comparison, two other 3A zeolites were prepared by techniques commonly used to make desiccant zeolites (i.e. method described in U.S. Pat. No. 2,882,243) to have wet test values of 9.3 (Sample B) and 10.1 (Sample C).
EXAMPLE 2
The zeolite 3A samples prepared in Example 1 were each separately compounded with an organic matrix comprising 90 wt. % ethylene/propylene/butene terpolymer (Eastman EASTOFLEX T1035) and 10 wt. % polyisobutylene tackifier to form 5 gallon samples at 40-60 wt. % zeolite loading using a Brabender mixer. The viscosity of the resulting compositions was measured at 124° C. and 800 sec -1 shear rate.
A plot of viscosity vs. adsorbent loading for various adsorbent/organic matrix composites was made. The results clearly indicate that the single crystalline material (Sample A) exhibits significantly less viscosity than the polycrystalline zeolites at equivalent loading.
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Crystalline molecular sieves which comprise mostly single and/or twinned crystal particles can be loaded into organic matrices in comparatively high amounts with less viscosity buildup than molecular sieves conventionally used for such desiccant applications. Desiccant/organic matrix compositions made with the single and/or twinned crystal zeolites exhibit improved physical integrity and/or improved rheological and adsorption characteristics in comparison to conventional systems. The compositions are especially useful in insulated glass window spacer applications.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an automatic unloading and stacking apparatus for unloading and stacking tubular articles from a circular sewing system.
2. Description of Background Art
Conventional automatic unloading and stacking devices used to unload tubular garments from an automatic sewing machine operate in the area immediately in front of the sewing equipment. This is the same area that an operator must occupy in initially loading the garment onto the automatic sewing machine. As a result, conventional unloading systems decrease the efficiency of the sewing process and unduly hinders the operator's ability to use the sewing machine by requiring the operator to work around the unloading system.
U.S. Pat. No. 3,865,058 issued to Rovin et al., discloses one conventional type of front unloading stacker device. In this device, a sewing station for sewing tubular articles is disclosed as having a pair of tensioning drums around which the tubular article is rotated during a sewing operation. The device further includes an extender bar having a pair of elongated rods supporting a transversely disposed bar at their forward ends. In its retracted position, the extended bar assembly is positioned so that the cross-bar lies directly in front of the drums extending therebetween. When the sewing operation has been completed and the side seam properly relocated the sewn article can be ejected from the sewing machine by activating the extender bar assembly to project a cross-bar in a forward direction. When the extender is actuated, the cross-bar engages the bottom of the sewn article and carries it outward to withdraw the article from the supporting drums. When the extender bar has been fully projected, it comes into range of a pair of gripping jaws of a folder stacker assembly. The jaws are actuated to close lightly and to engage the end of the sewn article. Both the extender bar and the folder stacker are then actuated in a retracting direction. The completed sewn article is then released by the folder stacker and draped over a stacking bar.
The above conventional unloading and stacking device has at least two distinct disadvantages. First, the automatic unloading and stacking system interferes with the loading operation since it is necessary for the unloading and stacking process to be completed before another article to be sewn can be loaded onto the sewing station. Second, because of the configuration of the unloading system, an operator must stand clear of the front of the sewing station during the unloading process. Each of these disadvantages result in the operator having to load workpieces on the equipment using ergonomically unsound motions in order to avoid the unloading system. Current systems do not address these problems.
OBJECTS AND SUMMARY OF THE INVENTION
The present invention relates to a method and apparatus disclosed for the automatic unloading and subsequent stacking of tubular articles such as sweat pants, T-shirts, pillowcases, etc., which are sewn in a circular fashion provided with a top or bottom sewn edge.
It is an object of the present invention to provide an automatic unloading and stacking apparatus which is capable of unloading and stacking a sewn article without interfering with a subsequent loading operation of the sewing station.
Another object of the present invention is to provide an automatic unloading and stacking apparatus that allows an operator of the system to load the sewing station in an ergonomically sound position.
A further object of the present invention is to provide an automatic unloading and stacking apparatus which decreases the cycle time and increases the efficiency of an automatic sewing process.
These and other objects of the present invention are accomplished by an apparatus for unloading and stacking an article which is sewn at a sewing station, said sewing station having a front direction from which an operator inserts an article which is to be sewn, said apparatus comprising a reciprocating base member which approaches said sewing station from a side direction which is approximately perpendicular to said front direction; a pair of stack bars including a stationary stack bar and a clamping stack bar disposed in parallel with each other, said clamping stack bar being movable toward and away from said stationary stack bar; and support means for pivotally supporting said pair of stack bars, said support means being pivotally mounted to said reciprocating base member; wherein in operation said base member beginning in a home position away from said sewing station and during a sewing operation said base member and said pair of stack bars move toward the article such that one of said stack bars is on one side of the article and the other of said stack bars in on an opposite side of said article, said stack bars closing on said article thereby pinching the article between them, said support means being pivoted away from the sewing station in a manner that removes the article from the sewing station, and said base member moves away from said sewing station and returns to said home position where said stack bars position the article over a rest member.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1 is a side view of a circular sewing station with an automatic unloading and stacking apparatus according to a preferred embodiment of the present invention;
FIG. 2 is a top view showing of a circular sewing station with an automatic unloading and stacking apparatus according to a preferred embodiment of the present invention;
FIGS. 3A and 3B are top and side views, respectively, of a circular sewing station with an automatic unloading and stacking apparatus, with the stacking apparatus shown in a home position;
FIGS. 4A and 4B are top and side views, respectively, of a circular sewing station with an automatic unloading and stacking apparatus, where the apparatus is in a clamping position;
FIGS. 5A and 5B are top and side views, respectively, of a circular sewing station wit an automatic unloading and stacking apparatus, where the apparatus is moved to an unloading position;
FIGS. 6A and 6B are top and side views, respectively, of a circular sewing station with an automatic unloading and stacking apparatus, where the clamping arms which are supporting the garment are returned to the home position;
FIGS. 7A and 7B are top and side views, respectively, of a circular sewing station having an automatic unloading and stacking apparatus, which illustrate the garment G being draped over a material rest bar;
FIGS. 8A and 8B are top and side views, respectively, of a circular sewing station with an automatic unloading and stacking apparatus, where the garment G is shown draped over a rest bar and clamping bars are returned to their home position; and
FIG. 9 is a top view of a circular sewing system with two circular sewing stations each provided with an automatic unloading and stacking apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring in detail to the drawings and with particular reference to FIG. 1, an automatic unloading and stacking apparatus 10 is shown in combination with a sewing station S.
The unloading and stacking device 10 (distinguished by a first set of phantom lines in FIG. 1) includes a pivot arm 11 which supports a stationary stack bar 12 at a top portion thereof. A clamping arm 13 is pivotally attached to the pivot arm 11 by means of a clamping arm pivot pin 15. The clamping arm 13 supports at one end thereof a clamping stack bar 14. The pivot arm 11 is supported at a lower end thereof by a pivot pin 16 which is mounted to a slidable base member 17. The slidable base member 17 is disposed on a pair of rails 18 on which the slidable base member 17 reciprocates from a home position as shown in FIG. 2 to a second position as shown in FIGS. 4A and 5A.
The sewing station S (distinguished by a second set of phantom lines in FIG. 1) includes a sewing machine 30. As shown in FIG. 2, a pair of tensioning rollers 31,32 are provided for supporting a garment G during a sewing operation. The sewing machine 30 is provided on a base 33.
As shown in FIGS. 1 and 2, a material rest bar 50 is provided on a slidable rest bar base member 51. The slidable rest bar base member 51 is provided with sliders 53 which slide along rails 52 between a home position and loading position. In the home position, the material rest bar 50 and slidable rest bar base member 51 are spaced from pivot arm 11 so as not to interfere with movement of the pivot arm 11 (and other associated elements) with respect to the sewing station 30. However, once the stacking and unloading device 10 has clamped a garment and returned from the sewing station 10, the material rest bar 50 and slidable rest bar base member 51 move toward and under an advancing pivot arm 11 as it drapes the clamped garment over the material rest bar 50 and ultimately releases the garment.
The operation of a preferred embodiment of the present invention will be described hereinafter with specific reference to FIGS. 3A,3B through 8A,8B.
In FIGS. 3A and 3B, the automatic unloading and stacking device 10 is shown with the base member 17 in a home position. The clamping arm 13 is open such that the clamping stack bar 14 is disposed in a position spaced from the stationary stack bar 12. The pivot arm 11 is in a substantially vertical position. The areas represented by phantom lines generally illustrate the interaction between the automatic unloading and stacking device 10 and the sewing station S.
As shown in FIG. 3A, the automatic unloading and stacking device 10 is disposed in a position to one side of the sewing station S outside the area immediately in front of the machine. A garment (such as shown in FIG. 1) is loaded on the sewing station tensioning rollers 31,32 from a sewing station front direction as illustrated by arrows A. With the slidable base member 17 in its home position as shown in FIG. 3A, the automatic unloading and stacking device 10 does not interfere with a sewing station loading operation.
With reference to FIGS. 4A and 4B, a garment G is shown as loaded on the tensioning roller 31,32 of the sewing station S. After a sewing operation has commenced, the slidable base member 17 of the automatic unloading and stacking apparatus 10, is moved in the direction of arrow B (See FIG. 4A) from the home position to a second position. While the slidable base member 17 is moved in the direction of arrow B, the clamping stack bar 14 moves behind the garment G while the stationary stack bar 12 moves in front of the garment G placing the garment G in between so that it enters the open area between the clamping stack bar 14 and the stationary stack bar 12.
When the sewing sequence has been completed, the clamping arm 13 moves to a closed position in the direction of arrow C, as shown in FIG. 4B. In the closed position, the garment G is pinched between the stationary stack bar 12 and the clamping stack bar 14. The pivot arm 11 is still maintained in a substantially vertical position.
FIGS. 5A and 5B illustrate the unloading process. As shown in FIG. 5B, the garment G which is pinched between the stationary stack bar 12 and the clamping stack bar 14 is pulled off of the tensioning rollers 31,32 of the sewing station S by rotation of the pivot arm 11 in the direction of arrow D. When the garment G is released from the tensioning rollers 31,32, it drapes over the clamping stack bar 14 and remains pinched between the clamping stack bar 14 and the stationary stack bar 12. The pivot arm 11 is then returned to its vertical position as illustrated by the phantom line depiction of the pivot arm 11'.
With reference to FIGS. 6A and 6B, the slidable base member 17 of the automatic unloading and stacking apparatus 10 moves in the direction of arrow E and returns to its home position, away from the sewing station. This allows an operator to load the next garment G without having to wait for the completion of the stacking sequence.
The slidable base member 17 returns to the home position, the pivot arm 11 is in the vertical position, and the garment G remains clinched between the stationary stack bar 12 and the clamping stack bar 14. Another garment G' is also shown as loaded onto the sewing station S while the stacking operation is underway.
FIGS. 7A and 7B illustrate the stacking operation. As shown in FIG. 7A, the slidable base member 17 is in the home position and the garment G is clamped between the stationary stack bar 12 and the clamping stack bar 14. In order to perform the stacking operation, the pivot arm 11 is rotated in the direction of arrow F, as shown in FIG. 7B. The garment G is then positioned over the material rest bar 50 as it moves toward the rotating pivot arm 11. At this time, the clamping arm 13 is moved to its open position, thereby moving the clamping stack bar 14 away from the stationary stack bar 12 and releasing the garment G, and leaving it to drape over the material rest bar 50.
With reference to FIGS. 8A and 8B, the pivot arm 11 has returned to its vertical position, the slidable base member 17 is still in its home position, the clamping arm 13 is in its open position, and the garment G is draped over the material rest bar 50. Once the pivot arm 11 has returned to its vertical position, the slidable base member can return to its home position at any time prior to movement of the pivot arm 11 toward the sewing station S.
During the stacking procedure, the sewing station has already commenced sewing another garment G'. During the sewing operation, the slidable base member 17 of the automatic unloading and stacking device 10 is again moved to its second position in order to begin another cycle of the unloading and stacking apparatus.
As shown in FIG. 9, the disclosed unloading system may be used with a single or multiple sewing stations. An automatic circular sewing system is shown having two sewing stations S1,S2 disposed adjacent to each other with an operator therebetween. The operator loads a garment G onto the sewing station S1, while the automatic unloading and stacking apparatus 10 associated with the sewing station S2 is preparing to unload the garment G' loaded thereon. In this way, the operator can load one sewing station while the other sewing station is executing a sewing process. Also, while the operator is loading a garment G onto the sewing station S1, the automatic unloading and a stacking device 10 associated with the sewing station S1 is preparing to stack the garment G' over the material stack bar 50. It is noted that more than two sewing stations could be operated by a single operator. With this arrangement, an operator can effectively load two sewing systems by moving within an area of approximately ninety degrees (90°). In addition, the sewing stations could be oriented differently than shown in FIG. 9.
Referring again to FIG. 1, it is noted that the movement of the clamping arm 13 can be carried out by hydraulic, pneumatic, electric servomotor, or equivalent means. Likewise, the movement of the pivot arm 11 about the pivot pin 16 can also be carried out by hydraulic, pneumatic, electric servomotor or equivalent means. Furthermore, the movement of slide base member 17 or slidable rest bar base member 51 can also be carried out by hydraulic, pneumatic, electric servomotor or equivalent means.
For purposes of illustrating the control system for the present invention, a pneumatic system 110 is used for operating the automatic unloading and stacking apparatus 10. The control system of the present invention includes a sensor S1 for determining when a garment is loaded onto the tensioning rollers 31,32 and for determining when a garment is unloaded from the tension rollers 31,32. An additional sensor S2 is provided on the sewing machine 30, for detecting the number of stitches performed on each garment. As the sensor S2 detects a predetermined number of stitches, the CPU 100 delivers a signal to the pneumatic control system 110 to move the slidable base member 17 from the home position to the second position, via pneumatic line 111.
When the sensor S2 detects a second predetermined number of stitches, representing completion of the stitching operation, the sewing machine is turned off. At this time, the control unit 100 sends a signal to the pneumatic control unit 110 to move the clamping arm 13 to a closed position via pneumatic line 112, thereby clamping the garment G between the stationary stack bar 12 and the clamping stack bar 14. The control unit 100 then sends a signal to the pneumatic control unit 110 to pivot the pivot arm 11 via pneumatic line 113, so as to unload the garment G from the tension roller 31,32. At this time, if the sensor S1 does not indicate that the garment has been removed, an error message is sent by the control unit 100 to stop the unloading procedure. The operator would then manually unload the garment G and restart the system.
If the sensor S1 indicates that the garment G is properly removed from the tension roller 31,32, the control unit 100 instructs the pneumatic control unit 110 to return the pivot arm to the vertical position via pneumatic line 113. The pneumatic control unit 110 is also instructed to return the slide base member 17 to the home position via pneumatic line 111.
After the slidable base member is returned to the home position, the pneumatic control unit 110 is instructed to pivot the pivot arm 11 in order to drape the garment over the material rest bar via pneumatic line 113. The pneumatic control unit 110 is then instructed to pivot the clamping arm 13 to an open position via pneumatic line 112, in order to release the garment over the material rest bar 50. The pneumatic control unit 110 is then instructed to return the pivot arm 11 to the vertical position via pneumatic line 113.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
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An automatic unloading and stacking apparatus and method for automatic unloading and stacking tubular articles from a circular sewing system. The system includes a mechanism for clamping and removing sewn garments from a circular sewing station that does not interfere with an operator's ability to access the sewing station. Once removed from the sewing machine, the sewn garments are then stacked in a remote location allowing an operator to load the next garment to be sewn.
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BACKGROUND OF THE INVENTION
The present invention relates to a radio paging system, and more particularly to a radio paging system enabling a battery saving function at each of its battery-powered receivers.
Battery saving systems of this kind include the "Digital Radio Paging Communication System" of Masaki et al., disclosed in on U.S. Pat. No. 4,194,153, issued on Mar. 18, 1980 and assigned to the present applicant (now known as NEC Corporation). In the battery saving system proposed by Masaki, a paging receiver intermittently operates at a predetermined first repetition period. When a base station transmits a battery saving release signal lasting longer than the first repetition period, the receiver continuously operates for a duration (longer than the total duration of the battery release signal and the base station's transmitted paging signal) to receive a paging signal. When this time has elapsed, the paging receiver again returns to its original intermittent operation.
In this prior art system, the first repetition period of each paging receiver is usually set so as to process calls adequately when system traffic is at its peak. Even when the base station transmits paging signals much less frequently, as, for example at night, each paging receiver still regularly repeats its intermittent operation, resulting in a waste of receiver battery power. This disadvantage has been handled by turning off the receiver's power supply at night. However, the paging receiver then misses paging signals.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a radio paging system capable of reducing the paging receivers power consumption.
Another object of the present invention is to provide a paging system capable of changing the repetition period of the paging receivers' operation depending on call traffic.
Yet another object of the present invention is to provide a paging receiver capable of changing the battery saving periods adapted to the paging system outlined above.
According to the present invention, there is provided a radio paging system, having a base station and a paging receiver, the receiver comprising: means for receiving a first carrier wave which is modulated with a first plurality of preamble codes and one of first address and control codes, and a second carrier wave which is modulated with a second plurality of preamble codes, the first plurality of preamble codes and a second address code, the first plurality of preamble codes being shorter than the second plurality of preamble codes; means for demodulating the first and second carrier waves; means for processing the output of the demodulating means into first and second plurality of preamble codes, first and second address codes, and control code; means for generating first and second control signals having first and second repetition periods, respectively, the first repetition period being shorter than the first plurality of preamble codes and shorter than the second reptition period, the second repetition period being shorter than the second plurality of preamble codes; means for supplying power to a prescribed part of the receiver in response to one of the first and second control signals; and means for supplying the second control signal from the generating means to the power supply means in response to the control code, and for supplying the first control signal from the generating means to the power supply means in response to the second plurality of preamble codes.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages of the present invention will become more apparent from the following detailed description read in conjunction with the accompanying drawings, wherein:
FIG. 1 is a block diagram illustrating an embodiment of the base station of a paging system according to the present invention;
FIGS. 2A to 2H are time charts for describing the operation of the base station illustrated in FIG. 1;
FIG. 3 is a block diagram illustrating an embodiment of a paging receiver for use in the radio paging system according to the present invention;
FIGS. 4A to 4F are time charts for describing the operation of the paging receiver illustrated in FIG. 3; and
FIGS. 5A to 5E are time charts for describing the repetition period switching operation for battery saving by the paging receiver illustrated in FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a subscriber's telephone set 1 is connected to a trunk 31 in an encoding unit 3 through a telephone exchange 2. A register 33 counts the calling signals received from the trunk 31, and converts a personal paging receiver's call number, transmitted from the calling party's telephone set 1, into a binary-coded decimal (BCD) number. A set call switch 32 permits an operator's manual entry of the receiver's number into the register 33. A memory circuit 35 stores the BCD number coming from the register 33. A BCD converter 36 converts the BCD number, supplied from the memory circuit 35 into a binary code. An encoding circuit 41 adds parity check bits to the output signal from the code converter 36 to provide a cyclic code.
A preamble code generator 37 repeatedly generates a unique word for a predetermined first duration of time (sufficient to repeat the generation 9 times in this instance) or second duration of time to repeat the generation 1,025 times). A sync code generator 38 generates a sync code to follow the unique word. A battery saving period switching (BSPS) code generator 39 generates a BSPS code to follow the sync code. An end code generator 40 generates an end code. A timing signal generator circuit 34 individually controls the circuits 35, 36, 37, 38, 39, 40 and 41, OR gates 42 and 43, and NAND gates 44 and 45, and supplies an encoding unit output through another NAND gate 46, to a transmitter 5. The transmitter 5 comprises an FSK modulator 51, a frequency converter 52, a power amplifier 53 and an antenna 54.
When trying to call a paging receiver (to be described in further detail below), an ordinary telephone subscriber dials on telephone set 1 the call number assigned for the paging receiver. The dial signal is inputted to the trunk 31 via the exchange 2, and further to the register 33. It also is possible for an operator to operate manually the set call switch 32 to enter the call number into the register 33. The register 33, having received a predetermined number of calls (for example, four), transfers to the memory circuit 35 all the call numbers, converted into BCD numbers. The memory circuit 35 keeps the call numbers until a read signal comes from the timing circuit 34. The capacity of the memory circuit 35 in this embodiment is 80 calls.
As call numbers are supplied to the memory circuit 35, the timing circuit 34 activates the preamble code generator 37 to supply the preamble code to the transmitter 5 via the OR gate 42 and NAND gates 44 and 46. The preamble code P (See FIG. 2A or 2B) is repeated nine times after,) (i.e., 155 msec×9=1,395 msec), each word (hereinafter called the unique word) consisting of a 31-bit code pattern as shown in FIG. 2D. The preamble code generator 37 has a 31-bit counter (which is activated by the output of the timing circuit 34,) a unique word supply counter, and a read-only-memory (ROM, for instance μPD501D manufactured and marketed by NEC Corporation) in which the code pattern of FIG. 2D is set in advance. This preamble code generator 37 reads out the contents of the ROM in response to the output of the 31-bit counter, and further repeats the reading of the ROM's contents, the number of repetitions being set by the unique word supply counter. After the (nine-word) preamble code P is supplied, the timing circuit 34 activates the sync code generator 38 to supply the sync code, which consists of the code pattern of FIG. 2E, in the position of word #1 in FIG. 2B. After the sync code is supplied, the timing circuit 34 supplies a read signal to the memory circuit 35, and at the same time activates the code converter 36, the encoding circuit 41, and the NAND gate 45, for at most 80 words (155 msec×80=not more than 12.4 sec,) as shown in FIG. 2B.
If call numbers are stored in the memory circuit 35, these numbers are transferred to the code converter 36 one by one, in the order of their storage, in response to the read signal from the timing circuit 34, until the memory circuit 35 is cleared. The code converter 36 converts BCD numbers into 21-bit binary codes. The cncoder 41 adds 10 parity check bits to the 21-bit information codes to supply an address number word representative of a the call number and consisting of the Bose-Chaudhuri Hocqunghen BCH (31, 21) cyclic code, to the transmitter 5 via the NAND gates 45 and 46. An example of code pattern of address number words is shown in FIG. 2G. As illustrated in FIG. 2B at most, 80 address number words, from #2 to #1 in that order, are supplied consecutively. The encoding circuit 41 may be composed of shift registers and adders as described in Wesley Peterson, "Error-Correcting Codes," pp. 149-152 (1962, The M.I.T. Press.) When the memory circuit 35 is cleared, its output is supplied to the timing circuit 34. The timing circuit 34 then suspends the operation of this the circuits 35, 36 and 41, and at the same time activate the end code generator 40 to send the end code E to the transmitter 5 via the OR gates 42 and 43 and the NAND gates 44 and 46, as shown in FIGS. 2A and 2B. The one-word code pattern of the end code E, shown in FIG. 2H, is a pseudonoise (PN) pattern consisting of 31 bits. The end code generator 40, which may be composed similarly to the preamble signal generator 37, repeat the end code E twice (155 msec×2=310 msec).
After the end code generator 40 has supplied code, the timing circuit 34 starts its built-in timer. In this embodiment, this timer is set to 2 minutes and 38.72 seconds (1,024 words×155 msec). If there is a new call number from the memory circuit 35 within this period of time, the timing circuit 34 repeats the foregoing series of actions. The sequence of signals at this time is shown in FIG. 2A.
When the set time has lapsed, the timing circuit 34 acts to change the battery saving repetition period. Thus the timing circuit 34 starts the preamble code generator 37 to supply nine unique words similar to code P in FIG. 2B, and then enables the sync code generator 38 to supply the one-word sync code shown in FIG. 2E. Further, the timing circuit 34 starts the BSPS code generator 39 to supply at least one word of BSPS code consisting of the 31-bit pattern shown in FIG. 2F, and then starts the end code generator 40 to supply two words of the end code of FIG. 2H. The timing circuit 34 generates no output unless a new call number is supplied to the memory circuit 35.
When a new call number is supplied to the memory circuit 35, the timing circuit 34 starts the preamble code generator 37. At the same time, by supplying a unique word supply counter switching signal to the preamble code generator 37 through a connecting line 47, the timing circuit 34 changes from 9 to 1,025 the count of the unique word supply counter within the preamble code generator 37, so that 1,025 unique words (P' in FIG. 2C) are supplied from the preamble code generator 37. After that, the timing circuit 34 suspends signal supply for a nine-word length of time, re-starts the preamble code generator 37, and at the same time changes from 1,025 to 9 the count of the unique word supply counter within the preamble code generator 37 by supplying the unique word supply counter switching signal, so that the signal sequence of FIG. 2B is supplied. The aforementioned signal sequence is illustrated in FIG. 2C. The transmitter 5 transmits through the antenna 54 a carrier wave modulated with an output signal sequence provided from the encoder unit 3.
FIG. 3 is a circuit diagram illustrating a paging receiver according to the present invention. The operation of this receiver will be described below with reference to time charts of FIG. 4.
A modulated carrier wave transmitted from the transmitter 5 on the base station side is picked up by an antenna 100, and received and demodulated by a receiving section 200 to be converted into a baseband signal. This baseband signal is shaped by a waveform shaping circuit 300 into a rectangular wave, which is supplied to a signal selecting circuit 400. These operations are, performed during a period of 2t (where t is one-word length of time) while every part of the receiver is supplied with power. For a subsequent period of 5t, the receiving section 200 and the waveform shaping circuit 300 are not supplied with power. This 2t on/5t off cycle represents one mode of the receiver's battery-saving function, as shown in FIG. 4B, and which will be described below in greater detail.
Now, when the paging receiver receives the modulated carrier wave shown in FIG. 4A, a bit-sync circuit 410 regenerates a clock signal which is bit-synchronized with the demodulated signal, and supplies the clock signal by way of a line 900 to a preamble code detector 420, a sync code detector 430, an end code detector 440 and an address code detector 450. The ouput of the waveform shaping circuit 300 is supplied to one input of the preamble code detector 420 through an AND gate 486. The other input of this AND gate 486 is connected to the Q output of a flip-flop (F/F) 730 within a pulser circuit 700. The Q output of the F/F 730 is high only when the battery saving function is turned on, but it is low when the function is turned off. Therefore, the signal to the preamble code detector 420 is given only when the battery saving function is on.
Upon detection of the preamble code, the detector 420 provides the detection pulse of FIG. 4C at a connection line 901. The F/F 730 of the pulser circuit 700 is set by this detection pulse, and the Q output of the F/F 730, passing through a NOR gate 740, keeps a switching transistor 750 turned on.
Consequently, power is supplied to all parts of the receiver, so that the receiver's battery-saving function does not operate. Meanwhile, the Q output of the F/F 730 becomes low to close the AND gate 486. The pulse, shown in FIG. 4C. of the line 901 also starts a timer 460 which, in response to the clock signal from the line 900, begins counting the time. This timer 460 is set for a period of 9t (the third duration of time), as shown in FIG. 4B.
Now supposing that no sync code (#1 in FIG. 4A) is detected within 9t, a time-out signal is outputted to a line 902 and resets the F/F 730 through an OR gate 490. As a result, the Q output of the F/f 730 becomes low and turns off the switching transistor 750 via the NOR gate 740 to turn on the receiver's battery saving function again. Meanwhile, the Q output of the F/F 730 becomes high, and the AND gate 486 opens.
If the sync code (#1 in FIG. 4A) is detected within 9t, a detection pulse, as shown in FIG. 4D, is outputted to a line 903. This detection pulse resets the timer 460 via the line 903, and at the same time causes a timer 470 to start counting. The timer 470 is set so that the fourth duration of time is 80t, as shown in FIG. 4B. After 80t, the switching transistor 750 is turned off, as occurs in the case of the timer 460 after 9t has elapsed, and the receiver's battery-saving function operates again, in the above-mentioned 2t on/5t off cycle.
The circuit structures of the preamble code detector 420, the sync code detector 430 and the end code detector 440 are similar, so the structure of the sync code detector 430 now will be described as representative of the three. The sync code of FIG. 2E is provided to a 31-bit shift register 434. The 31-bit output of the shift register 434 is supplied to an AND gate 435 directly when the corresponding bits of the sync code are "1," and through inverters 431, 432, 433 and so on when the corresponding bits of the same are "0". Only when the 31 bits supplied to the shift register 434 are respectively identical to the 31 bits of the sync code does the AND gate 435 pass a detection pulse (FIG. 4D) through the line 903. The preamble code detector 420, sync code detector 430 and end code detector 440 differ from one another only in the positions of inverters arranged to match the "0" in the code patterns of FIGS. 2D, 2E and 2H.
Next, if the address code of this receiver (supposed to have the code pattern of FIG. 2G) is transmitted from the base station in the position of the #81 word of FIG. 4A, the address code detector 450 will output a detection pulse shown in FIG. 4E over a line 904, and this pulse is supplied to an alert tone generator 500 to activate it. The generator 500 outputs a continuous alert, as shown in FIG. 4F, which drives a speaker 600 to let the receiver's bearer know that s/he is being paged. In FIG. 4F, α indicates a time at which a reset switch 501 is pressed to stop the alert tone.
Now the operation of the address code detector 450 will be described in detail. A sync code detection pulse (See FIG. 4D) at the line 903 activates a read pulse generator 454, comprising a 31-bit shift register, to generate sequentially and cyclically at output terminals #1-31 the read pulses synchronized with the clock signal from the line 900. In a programmable read-only memory (PROM) 453, the address code assigned to the paging receiver is written in advance. The PROM may be of the so-called detachable cord-plug type. First, in response to a read pulse from bit position #1 of the read pulse generator 454, the first bit of the address code stored in the PROM 453 is read out, and supplied to one of the input terminals of a two-input exclusive NOR gate 451. An output from the waveform shaping circuit 300 is supplied to the other input terminal of the gate 451. This gate 451 is open if the two inputs are the same, or closed if they are different. A 31-bit counter 452 counts the pulses when the gate 451 is open. Since the clock signal from the line 900 is supplied to the counter 452, if each respective pair of one of the consecutive bits from the PROM 453 and one of the outputs of the waveform shaping circuit 300 is found by the exclusive NOR gate 451 to be identical the counter 452 will count up sequentially until the 31st bit and, if all the 31 bits are found to be identical will, supply a detection pulse (FIG. 4E) over the line 904. Then the counter 452 is reset by the trailing edge of the read pulse of 31st bit to prepare itself for the next counting.
FIG. 5A shows a modulated carrier wave transmitted from the base station. Unless four call number signals from the telephone exchange 2 (See FIG. 1) are supplied to the encoding unit 3 of the base station within a prescribed length of time (1,024 words' length), the base station's transmitter 5 sends a nine-word (9t) preamble code (P in FIG. 5A), followed by a one-word sync code (1 in FIG. 5A), a one-word battery saving period switching (BSPS) signal (2 in FIG. 5A) and a two-word end code (E if FIG. 5A). After that, the modulated carrier wave emission from the transmitter 5 is suspended until four call number signals are registered in the memory circuit 35 of the encoding unit 3. Upon registration of four address number signals, as described with reference to FIG. 2C, a modulated carrier wave is emitted from the transmitter 5, as shown in FIG. 5A.
The battery saving operation of the paging receiver shown in FIG. 3, corresponding to the modulated carrier wave of FIG. 5A, is represented by FIG. 5B. The receiving section 200 and the waveform shaping circuit 300, regulated by the pulser circuit 700, are repeatedly turning on (for 2t) and off (for 5t) as shown in FIG. 5B. When a preamble code P is detected by code detector 420 while the receiving section 200 and the waveform shaping circuit 300 are within the 2t period when they are on, a detection pulse is generated at point c 1 of FIG. 5C. At this time, as described with reference to FIG. 4C, the timer 460 sets a third duration of time 9t as shown in FIG. 5B. A sync code, as described with reference to FIG. 4D, is detected at point d 1 of FIG. 5D, and the timer 470 sets the fourth duration of time 80t. Here a battery saving period switching (BSPS) signal 2, shwon in FIG. 5A, is detected by a BSPS signal detector 480 (see FIG. 3), and a detection pulse of FIG. 5E is outputted over the line 905. The pulse on the line 905 resets the timer 470 by way of an OR gate 485, resets the F/F 730 by way of the OR gate 490, and inverts its Q output to below. As a result the switching transistor 750 is turned off via the NOR gate 740. Again the receiver's battery-saving function is thereby rendered operational.
The detection pulse on the line 905 also sets a F/F 760, and inverts the outputs Q and Q. The outputs Q and Q of the F/F 760 are connected to AND gate 780 to keep it closed, and to AND gate 770 to keep it open. A control signal is fed to the other input terminal of the AND gate 770 at a repetition period represented by β 2 in FIG. 5B, while a control signal is fed to the other input terminal of the AND gate 780 at a repetition period represented by β 1 in FIG. 5B. These control signals are supplied from a control signal generator 720, which frequency-divides the output of an oscillator 710 to generate the required control signals at the repetition periods β 1 and β 2 . The pulse to reset and initialize the control signal generator 720 is obtained by inverting the output Q of the F/F 730 with an inverter 790. Consequently, the NOR gate 740 is controlled by the output of the AND gate 770, and repeatedly turns on and off the switching transistor 750 at the repetition period of β 2 . The repetition period β 2 represents another mode of the receiver's battery-saving function, as will be described below.
When the repetition period is β 2 , power is supplied to all parts of the receiver for 2t; for the following 1021t, power is not supplied to the receiving section 200 and waveform shaping circuit 300. Since the average current of the receiving section 200 and the waveform shaping circuit 300 is 3 mA and that of the signal selecting circuit 400 and the pulser circuit 700 is 150 μA, the average current during the period β 1 is ##EQU1## Accordingly, the amperage for the paging of the present invention is only 16 percent of that involved if there were no switching of repetition period from β 1 to β 2 .
Then, if a preamble code of 1,025t in time length, represented by P' in FIG. 5A, is transmitted from the base station, the preamble code detector 420 outputs the detection pulse to the line 901 at point c 2 in FIG. 5C. The pulse on the line 901 resets the F/F 760 and inverts to outputs Q and Q. As a result, the AND gate 780 is opened, and the AND gate 770 is closed, the battery saving period changing from β 2 to β 1 . Since the pulse on the line 901 (at point c 2 in FIG. 5C) induces actions similar to those described with reference to point c 1 in FIG. 5C, battery saving is suspended for a period of 9t. Because no sync code is detected within this period of 9t as illustrated, the receiver resumes battery saving in response to a time-out signal from the timer 460. A 9t pause is provided between preamble codes P' and P on the base station side to ensure the possibility of suspending battery saving, which might otherwise be impossible if the preamble code P arrives immediately following the code P' within the 9t period during which the receiver is waiting for a sync code.
Next, the processes in which a preamble code P is detected at point c 3 in FIG. 5C and a sync code is detected at point d 2 in FIG. 5D are the same as in FIGS. 4C and 4D, respectively.
Following an address code, an end code E (see FIG. 2H) is transmitted to let the paging receiver resume battery saving by detecting the end code with the end code detector 440 and resetting the F/F 730 via the OR gates 485 and 490 in response to the end code detection pulse, so that the paging receiver may take no unnecessary receiving action when the address code transmission from the base station is less than 80t.
Athough only the use of the code pattern of FIG. 2D for the preamble code is referred to in the foregoing description of the preferred embodiment, the preamble code can obviously be replaced with any other code different from the sync code, battery saving period switching code, end code, and address code.
It will be readily understood that the period β 2 can be extended by grouping the paging receivers. The call number capacity is the 21st power of 2 (equal to 2097152) because the call number code has 21 information bits, as shown in FIG. 2G. For example, these 2097152 different call numbers can be grouped into 200 groups, each of which has 10,000 call numbers and is headed with a preamble code unique thereto. In such a grouped number system, the encoding unit comprises a sorter provided between the trunk 31 and the register 33 (See FIG. 1) with which the call numbers are sorted into prefixed groups. For each group, the encoding unit includes the register 33, the decimal-binary converter 36 and the encoder 41 (See FIG. 1). The encoding unit also comprises a transmission sequence arranging circuit following the NAND gate 46 to arrange the encoded group paging codes from the encoders 41 to a paging code. On the other hand, each paging receiver which is in a given group, has to have a preamble code detector unique to the given group. Although this unique preamble code detector makes the paging receiver design somewhat complex, composing the decoder of a PROM of the code-plug type in the same manner as the address code detector 450 (FIG. 3) will simplify the design, and if these preamble and address code detectors are placed in a single PROM, the design will be even simpler.
As described earlier, the radio paging system according to the present invention sets more than one duration and repetition period for battery saving pulses for the paging receiver, resulting in the reduction of the paging receiver's power consumption. In addition, the power switch of the paging receiver can be eliminated so that the receiver is more compact and is easier to operate.
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A radio paging system, comprising a transmitting base station and a paging receiver with a battery-saving function. The paging receiver operates intermittently at different repetition periods, depending on the call traffic density. When there are fewer calls, the receiver operates less frequently, in order to avoid unnecessary operation and consequent battery drain. When there is a call to be sent, the period between attempted detections of a preamble code word is shortened. The receivers then lengthen the period for detecting a message, and receive a sync code word, followed by an address code word, which alerts the particular receiver being paged, an alert tone being generated. The message ends with a battery saving code word and ending code word. The battery saving code word alerts the receivers to lengthen the period between attempted detections of the preamble code word. The variation in length of periods between attempted detection is a battery-saving feature.
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BACKGROUND OF THE INVENTION
This invention relates to `bionic dunes` which can best be defined as the re-creation of eroded and missing natural primary ocean-front sand dunes, but with a very necessary improvement which would make them non-eroding, and thereby worth re-creating.
Their purpose and functions are two-fold, as they would not only protect the upland topography of barrier islands (commonly called `barrier beaches`) and the mainland behind them from increasingly powerful hurricanes, such as the type that recently ravaged the southeastern coastal states of the continental United States, but also be restorers, equalizers and stabilizers of the beaches and shorelines on their seaward side. The reasoning behind these important additional functions is given below, based on over 60 years of observation as a resident real property owner of two houses in two communities on a `barrier beach`, one of which has been in the inventor's family for more than 82 years. The other was built in 1951; both are still owned by him and have given him constant opportunities to study one beachfront with dunes and the other without dunes. He has, over many years, observed with intense interest the interactions between ocean surf-waves during severe storms and high tides, in all seasons, and the two separate sand-beach shorelines when with and without their natural primary sand dunes.
The principle in the creation of `bionic dunes` is to provide non-eroding `civilization resistant` oceanfront primary sand dunes systems embodying a passive (non-colliding) method of ocean surf-wave control without the fragility of the all-natural dunes with their inability to survive the many varieties of damage, such as: building on, treading on, driving on with off-road vehicles, and damages from construction machines, trucks and bulldozers disfiguring their bases, plus general acts of total disregard and/or ignorance of their importance in the balances nature brings to its diverse processes within the relationship between primary dunes and their adjacent beaches. Most of said damage has been done in the last 60 years.
A symmetrical primary oceanfront sand-dune line, in observing reciprocal processes after a series of waves have broken on a beach which is backed by a gently rising sand-dune base, is seen to lead each on-rush of sand-bearing water quickly, smoothly and quietly uphill to a `stall-point`, where the water loses its momentum, falls back toward the berm of the beach, at which time its sands in suspension begin to fall out while much of the slowly moving water is being absorbed in the porous sands of the berm of the beach, as the remaining water, if any, is met by a subsequent run of sand-carrying wave-water coming in across the berm, headed for the base of the dunes, repeating the process just described. This process, repeated every minute, for hours, days, and nights until either high tides, storms or water-surges abate, adds great amounts of sand to a beach from the dunes' base, seaward, over the berm, and to the edge of the shoreline.
The same weather and tide conditions prevailing, on a stretch of beach with no dune line, therefore: no inclined dunne-base, `stall point`, would allow the same water mass to race over and past the upland end of the berm and over the sands where a dune-line should have been, and continue into the inner parts of the island without depositing its sands in suspension on any part of the beach area. If this rush-over of water continues, it could begin eroding the area of the old dune-line over which it now rushes. Within hours a breakthrough `cut` could become deep-enough to look like a stream-bed, later like a riverbed, and thereafter an inlet is created. This explains how important the presence of primary oceanfront sand dunes are to adjacent beach preservation.
In areas where primary dunes were sufficiently damaged to lose their effectiveness as described above, the adjacent beaches began to suffer from increasing erosion. It was at that time that community managers and property owners, in some of the affected communities, began to show interest in erecting sand-catching barriers on their beaches. Still not aware that the loss of dunes could have any bearing on their beach problems, they concentrated on securing federal, state or county funds to install rock groins at a 90 degree angle to the beaches. Other blunt confrontational structures also came into vogue, such as jetties, seawalls, revetments, sta-pods and offshore rockpiles. Soon after installation of any one of the foregoing, off and on the shorelines of many eastcoast states, extremely damaging side-effects were connected to their presence. Groins produced `scouring action` on the downdrift side of the littoral drift off Long Island, N.Y., causing loss of as much as half the width of beach for thousands of yards down the beach. Jetties caused uncontrolled sand deposits on their updrift side with sand overflowing the jetties' landward rocks and being washed into the inlet it was designed to protect, forming unwanted shoal waters and sandbars as well as accretion on the opposite bank of the inlet. Seawalls, built along upland sides of beach berms caused a single-wall sluiceway effect, resulting in complete loss of entire beaches, such as along the `Jersey Shore` in New Jersey, south of N.Y. harbor. Revetments cannot be considered to be much better than seawalls, because, they, too, can be undercut at their bases and moved into disarray in heavy storms, losing their ability to protect much of anything. Sta-pods and indiscriminately dumped rockpiles of small and large rocks cause underwater currents to disperse, creating underwater turmoil, sending currents in any direction, resulting in unpredictable erosion of a shoreline.
The message we should get from the foregoing observations is that blunt confrontational structures, in attempting to control surfwave action, only cause more damage than they were installed to prevent. We also must conclude that the only successful method is that of passive control wherein heavy, powerful masses of fast-moving water, from breaking waves on a beach, can be guided up the gentle slopes of dune-bases to an increasingly greater incline until a `stall-point` is reached, not only causing each wave to stop and return seaward, but to deposit its sands in suspension in such a beneficial way that the dunes are also instruments of sand nourishment to the adjacent beach, and therefore also a stabilizing force in the best methods known to man--the natural scheme of things.
In view of the foregoing, it certainly would be rational to conclude that if blunt confrontational structures are removed from oceanfront sand beaches and only the passive method of wave-water control, as described above, is applied to such beaches, there should be dependable beach build-up and stabilization easily tolerating the normal, temporary, yearly cyclical erosion and accretion, from fall and winter, to spring and summer months, caused by seasonal changes along, for example, Long Island's oceanfront beaches, where, with a constant west-flowing littoral drift, the winds and storms in the cold months prevail out of the northeast, but the winds and storms in the warm months prevail from the southwest. The two easterly forces, combined in `winter` erode the beaches, but the two opposing forces in `summer` cause opposite-moving water-borne* sands to fall out of suspension at the points of contact occurring along the shoreline of those beaches, causing predictable restoration of the shoreline in time for the summer season.
If only passive processes are put back to work there would be every reason to expect that we would again have wide, stabilized beaches paralleling those indispensable sand-nourishment tools of the ages--the primary oceanfront sand dunes, which aid in building higher berms which could offset the sort of alleged consequences as stated in the following:
The questionable theory that such beaches will be diminished in width by a rise in sea-level rate of a foot by the year 2000; one foot, three inches by 2010; and three feet by 2040, has been disputed by a recently publicized contention that the `greenhouse effect`, caused by global warming from planet-wide carbon emissions, by the year 2000 shall not be permitted to continue, as international agreements are being reached to eliminate all present sources to be replaced by non-polluting alternative energy sources. Therefore, the future for our shorelines now appears to be brighter and `bionic dunes` can be built without fear of their having to retreat from a steadily encroaching ocean, as apathy and ignorance is conquered in the proper treatment of our planet.
A number of U.S. Pats. have been issued which deal with beach destruction and related problems.
U.S. Pat. No. 20,105 issued in 1858, which illustrates how far back man has been dealing with this problem, discloses a sea wall consisting of a frame containing stones.
U.S. Pat. No. 591,256 shows a system of plants arranged to protect levees.
U.S. Pat. No. 1,428,808 illustrates the use of partially embedded walls to prevent the undermining of water washed banks.
U.S. Pat. No. 2,190,003 discloses the use of stone-settings on a sandy subsoil and the injection of a stabilizing agent under the stones for fixing and immobilizing water front property.
U.S. Pat. No. 4,345,856 describes the stabilization of embankments utilizing the development of growth on the embankment.
U.S. Pat. No. 4,362,432 shows the use of a sea wall with an energy dissipating and absorbing structure for preventing the erosion of beaches.
U.S. Pat. No. 4,367,978 describes apparatus for halting beach erosion employing prism-shaped slotted modules placed in the wave breaking areas.
U.S. Pat. No. 4,498,805 describes a breakwater made of modules designed to trap the wave water and to dissipate the energy in so-called water-to-water interactions.
U.S. Pat. No. 4,521,131 illustrates a lightweight semi-flexible dike made up of layers of mixtures of shells, sand and cement and the water side of the dike covered with a dike cover which is permeable to the water.
U.S. Pat. No. 4,804,293 discloses a flexible layer structure for use in covering earthworks subject to water contact.
None of the preceding patents teaches or suggests the present invention.
SUMMARY OF THE INVENTION
This invention largely overcomes the drawbacks and shortcomings of techniques utilized up to now to stabilize beach front property.
The invention depends on the use of a dune-structure system to control ocean-front heavy-weather surf-wave action without blunt collisions, thus avoiding the ensuing turmoil, which creates destructive side effects to surrounding topography.
In accordance with the principles of this invention there is provided a primary oceanfront dune structure which accomplishes several desired results. It prevents underwashing of the dune face, eliminates wave impact by relying on gravity rather than collision and channels, back to the sea, waves which otherwise would be capable of eroding any upland topography if they were allowed to continue in their original direction.
A preferred embodiment of the invention comprises a durable protective shielding containment-shell protecting its inner hard-packed sand mass, hydraulically built up, on top of several layers of broken concrete-sidewalk slabs placed inside the base of said dunes, in line with the elevation of their baseline for the primary purpose of further stabilizing the double line of tall poles which are set into the watertable, in order to create suction to prevent uplifting forces and prevent sinkage, as well, since water-packed sands are resistant to any further intrusions into their surfaces. The face of the dunes are concave on a vertical plane, shielded by impervious, high-impact-resistant, non-biodegradeable, heat and cold tolerant, non-eroding materials of choice, i.e., molded thermoplastics; reinforced resins; reinforced concrete; and others such as a new bulkheading grade material from recycled plastics now being tested by the Town of Islip, N.Y. to replace treated wood bulkheading, which may be made available in longer lengths required for best construction after this invention is patented. Also its contiguous toe is buried well under the thickness of the berm of the beach, to prevent undercutting into the base of said dunes and the underwashing of its contents. Further safeguards against underwashing and sinking is the placement of a bottom liner of durable, non-biodegradeable material under the slab-pile around the pilings mentioned above, to prevent slab sinkage as well as underwater intrusion during periods of high tides and water surges during hurricanes. The toe is attached to non-biodegradeable stringers, anchored underground to buried aggregate anchors, also of a non-biodegradeable material of choice. The face sections of the dunes are stabilized by a row of long pilings interconnected by supportive stringers to which they are attached at two points; under the crest and at mid-point, the area of the 90 degree `stall point`. The peak of the dune projects only slightly, toward the sea, inducing high-climbing waves' waters to be directed away from the crest. The top of the dunes are covered with native, heavy-rooted two-to-three foot tall beachgrass which is indigenous to seashores in the northeastern U.S. Its massive root systems serve to hold large areas of sand together in its hair-roots, making an excellent deterrent to wind and water erosion, while its long, two-to-three foot long, blades catch any sand grains blowing from the beach, over the peak of primary dunes, thus capturing and holding them for the time the dunes exist. The face material is molded to go out slightly from and turn back over the peak, and to go two feet or so in a slightly depressed, pan-shape to accommodate the frontal planting of beachgrass roots in a line no higher than those naturally-rooted plants just behind (upland) from them to create a smooth flowing crest-line from peak to upland grasses. The gently sloping backs of the dunes are made as wide (base to upland) as possible, space permitting, because their width gives them their formidable strength in times of greatest stress--during hurricanes.
The height of the original natural primary oceanfront sand dunes, from top of berm of beach to top of dunes' face-peak has been estimated (by Fire Island national Seashore personnel) as having been up to 45 feet at their highest attainment along our Atlantic barrier beaches and approximately 25 feet at their lowest attainment before erosion. `Bionic dunes` could be similar in height, depending upon choices of planners to meet the protective needs of a particular region.
The construction just described would make the use of devices such as groins, revetments, etc., obsolete along the shorelines of most ocean beaches as they have been seen to cause extremely damaging side effects as mentioned elsewhere in this application.
It is the inventors opinion, and that of many other knowledgeable seashore property owners of many years of experience, that, eventually, all blunt confrontational types of structures must be removed from beaches already damaged by their side effects (in order that restoration of damaged areas may be possible through passive-resistance).
It is thus a principal object of this invention to make available a structure which is capable of protecting, stabilizing and building up beaches without producing damaging side-effects to adjacent areas.
Other objects and advantages of this invention will become obvious from the following description of preferred embodiments of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross section of a dune constructed in accordance with the principles of this invention.
FIG. 1A, 1B, and 1C, illustrate graphically the natural build-up of sand on a bionic dune.
FIG. 2 is a section along 2--2 of FIG. 1.
FIG. 3 is a section taken along 3--3 of FIG. 1.
FIG. 4 is a detail showing construction of the crest of the dune.
FIGS. 5 and 6 are schematic illustrations of wave action on a sand dune built in conformance with the principles of this invention.
FIG. 7 is a detail showing one way of anchoring the lower part of a bionic dune.
FIG. 8 is a cross section of a dune constructed to permit access to the beach.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1, 2, and 3, there is shown a dune 10 constructed in accordance with the principles of this invention. As is understood in the art, dune 10 extends along an ocean beach comprising the berm 12 with the mean high and low tides of the ocean indicated at H and L, respectively.
Dune face 11 of dune 10 extending along the length of the beach and facing the ocean is formed by a sheet 14 of impervious high-impact resistant non-biodegradable, non-eroding plastic extending from a toe 16 buried under berm 12 to a line 18 on the top of dune 10 where sheet 14 terminates. Sheet 14 is anchored by a first row of spaced anchors 22 parallel to the face for anchoring toe 16, a second spaced row of pilings 24 adjacent sheet 14 in a row below the crest 26 of dune face 11, and a third row of pilings 28 further inland. Pilings 24 are connected together by stringers 32 to insure that face 11 has adequate attachment to stabilize the face which will be described later. Pilings 24 and 28 also anchor the crest 26 of face 11.
Stringers 32 may be made of any suitable, long-lasting material such as 4"×6" treated wood or durable high-impact resistant plastic. Pilings 24 and 28 would typically be constructed of the same material used in pilings supporting docks and the like, i.e., wood which is treated to resist deterioration under the conditions of use. All pilings are set into the water-table's water-packed sands to obtain suction at their bases.
To construct dune 10, the area may or may not have to be excavated to permit a bottom liner 34 to be placed horizontally above the water table. Above liner 34 is built up a layer 36 of broken concrete slabs or slate, to further stabilize the long pilings. Liner 34 prevents the aggregate from settling through the sand below. None of the concrete ballast items are exposed to exterior forces
Filling out the remainder of dune 10 is hard packed sand 38 which forms with the top end of face sheet 14 at line 18 a smooth top surface 42 on which beachgrass 44 is planted using beach sand for this purpose to stabilize the top of dune 10 as is understood in the art.
Dune face 11 is in the form of a vertically extending arc, concave in shape, which extends the length of dune 10 facing the ocean. Wind and water driven sand 46 deposits on the lower portion of the arc. As seen in FIG. 5, the height of dune 10 is such that for a given location the average wave will lose momentum at a point 48 below crest 26, this point being defined herein as the stall point. Larger waves will be turned back as seen in FIG. 6, so that the curvature of the arc formed by face 11 is such that the direction of all waves climbing against face 11 would be reversed.
As seen in FIGS. 1A, 1B, and 1C over a period of time is built up layers of sand, 10a, 10b, and 10c.
For a detail of the manner in which toe 16 of dune face 11 is anchored, reference is made to FIG. 7. It will be seen that face 11 is provided with anchor 22 comprising a cemented pebble aggregate 102 pyramidal in configuration set below the top 12 of the berm of the beach extending up from the water table 105. Shown in cross section is a stringer 104 connected between anchors 22 and sheet 11. Stringer 104 is connected to aggregate 102. A U-bolt 108 is set through stringers 104 to engage loop 106. Lag bolts 110 are employed to attach face 11 to a face of stringer 104 Anchors 22 are spaced at 10-12 foot centers.
For more detail of the crest, reference is made to FIG. 4. Sheet 14 along the top of the dune is provided with holes 120 to encourage rooting into the sand below sheet 14. Hard packed sand 122 native to the area runs along the top of the dune, both above and below the horizontal section of sheet 14.
A modified dune construction to permit human access to the beach from behind the dune is shown in FIG. 8. Here, dune 200 otherwise identical to dune 10 previously described is provided, with access to the beach, at only within the bounds of a community and only minimally along the length of the beach. An inclined tunnel 210 is incorporated which can be formed by joined ten foot diameter sections of concrete reinforced pipe.
Steps 214 made of wood planks may be incorporated to facilitate movement through the tunnel, and railings may be provided if deemed to be desirable. A water tight door 216 hinged at the bottom may be utilized to close the tunnel during a hurricane, for example. For this purpose an electric lift motor 218 with a cable 218 may be used to open and close door 216.
At the top, a trap or other type of door 222 may be employed to close off the entrance to tunnel 210.
It will be seen from the construction of dune 10 that the breaking of waves occurs in a non-colliding and non-eroding manner so that dune 10 should remain stable indefinitely and under the most extreme circumstances.
In the event of a storm such as a hurricane which might cause waves to break over the top of dune 10 it will be seen that there is still no location where such waves are likely to cause any erosion.
While only certain preferred embodiments of this invention have been described it is understood that many variations are possible without departing from the principles of this invention as defined in the claims which follow.
An alternative to the use of slabs of broken concrete around the piling poles for added stabilization, as indicated in FIG. 1, would be the use of cross-bracing in the form of X's with short lengths of 2"×8" waterproof treated lumber, spiked to poles with #10 or larger common hot-dipped galvanized nails, thus eliminating not only the `rocks`, but the liner, as well.
The phenomenon of natural dunes' build-up against the seaward side of Bionic Dunes is an expected result of the design of a non-combative method of ocean wave-water control, during year-round storms and extremely high tides, devised to replace the increasingly controversial use of blunt-confrontational emplacements along oceanfront sand-beach shorelines. This invention creates not only a non-eroding `civilization resistant` primary oceanfront dune line system to protect upland topography, as well as mainland shorelines behind barrier beaches, but also a structural system capable of serving as a catalyst in causing continual build-up of new sands during periods of heavy wave-water intrusions to the extend where the armored face of Bionic Dunes becomes, in due course, covered with new sands until they reach up to the peak of the dunes' crest while also extending seaward, over the berm, for a distance approximating the height of the peak of said crest, thereby forming a completely different face-profile at an angle of slope of approximately 45 degrees. After that plateau is attained, as shown in the upper right corner on the first page of DRAWINGS, under FIG. 1C, particularly in the dotted-line, identified as 10C, subsequent water-borne sands are deposited over the berm of the beach, resulting in a higher berm, which, in turn, causes new amounts of sand to build-up seaward of the mean high-tide line, resulting in a widening of the beach. We would then have a dune-line, resulting in a widening of the beach. We would then have a dune-line similar in appearance, but greater in internal strength to those unarmored dunes which existed up to the first quarter of this century, together with their high, wide beaches.
As such seaward progression develops, the limited beach-access tunnels, in the form of: 10-foot inside-diameter sections of reinforced concrete, lap-jointed pipe, could be extended as desired and end piece re-contoured to fit the changed incline. An alternative would be use of the conventional over-the-dune boardwalk-and-railinged steps, however, not as well favored becuase ANY structure on or near dunes can encourage wind-blasting effect on crests as well as faces and toes of unarmored natural additions, under discussion in this paragraph.
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Bionic dunes for stabilizing an ocean beach and preventing the erosion thereof comprising a sheet extending the length of the beach having a vertically extending concave surface to turn back breaking waves. The toe midpoint and crest of the sheet are fixed by pilings while the sheet is backed up by water-packed sand below which a thin layer of aggregate is placed around the long pilings. The top surface of the crest and the sand is provided with vegetation to stabilize the top surface of the dune.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority of U.S. Provisional Application No. 61/235,290, filed Aug. 19, 2009, which is expressly incorporated herein by reference.
BACKGROUND
[0002] The causative agent for AIDS (acquired immune deficiency syndrome) is known to be a virus of the retrovirus family called HIV (human immunodeficiency virus). Infection with HIV does not, however, immediately give rise to overt symptoms of AIDS. The only indication of exposure to the virus may be the presence of antibodies thereto in the blood of an infected subject. The infection may lie dormant, giving rise to no obvious symptoms, and the incubation period prior to development of AIDS may vary from several months to decades. A person infected with HIV gradually loses immune function along with certain immune cells called CD4 T-lymphocytes or CD4 T-cells, causing the infected person to become vulnerable to pneumonia, fungal infections, and other, common ailments. Development of AIDS itself may be preceded by the AIDS-related complex (ARC) which is characterized by unexplained fever, weight loss, chronic cough, or diarrhea.
[0003] The reasons for the variable period between infection with the virus and breakdown of the immune system in an infected individual are poorly understood. This progression can be monitored using surrogate markers (laboratory data that correspond to the various stages of disease progression) or clinical endpoints (illnesses associated with more advanced disease). Surrogate markers for the various stages of HIV infection include the declining number of CD4 T-cells. In general, the lower the infected person's CD4 T-cell count, the weaker the person's immune system and the more advanced the disease state. Factors presently unknown may trigger proliferation of the virus with consequential disruption of the immune system. The victims of the disease are then subject to various infections and malignancies that, unchecked by the disabled immune system, lead to death.
[0004] At this time, there is no cure for AIDS and management of the disease with FDA-approved drugs is extremely costly. As the scientific community continues to study HIV and search for ways to manage the symptoms of AIDS, it is hoped that less expensive medications can be identified and easily distributed not only to those in the United States but also to those in developing countries.
SUMMARY
[0005] To address these and other needs in the art, the present invention generally provides methods of inactivating human immunodeficiency virus (HIV) in vitro or in vivo, and methods of treating HIV-positive patients and patients having acquired immune deficiency syndrome (AIDS).
[0006] Accordingly, in one general aspect, the present invention provides a method of inactivating at least 50% of HIV in an in vitro sample comprising contacting the sample with a composition comprising an effective amount of ammonium chloride.
[0007] Also contemplated are methods of treating patients. For example, the present invention provides a method of inactivating HIV in a patient comprising intravenously administering a composition comprising an effective amount of ammonium chloride to the patient.
[0008] In other embodiments, the present invention provides a method of treating a patient suffering from AIDS comprising intravenously administering a composition comprising an effective amount of ammonium chloride to the patient.
[0009] Another general embodiment of the present invention contemplates a method of delaying the onset of AIDS in an HIV-positive patient comprising intravenously administering a composition comprising an effective amount of ammonium chloride to the patient, wherein the onset of AIDS is delayed as compared to if the patient had not been intravenously administered the composition.
DETAILED DESCRIPTION
[0010] Methods discussed herein offer an economical way to study HIV in vitro as well as to treat HIV-positive patients, such as patients having AIDS, using compositions comprising ammonium chloride. One aspect of the invention is directed to a method of inactivating at least 50% of HIV in an in vitro sample comprising contacting the sample with a composition comprising an effective amount of ammonium chloride. Another aspect of the invention is directed to a method of inactivating at least 50% of HIV in an in vitro sample comprising contacting the HIV with a composition comprising an effective amount of ammonium chloride. In certain embodiments, at least 75% of HIV is inactivated. In certain embodiments, at least 90% of HIV is inactivated. Other degrees of inactivation are discussed herein. HIV may be further defined as HIV-1 or HIV-2, or a combination thereof. In some embodiments, the sample contains HIV virions. In some embodiments, the sample comprises human T-cells, such as human T-cell leukemia cells.
[0011] A composition comprising ammonium chloride may have an amount of ammonium chloride ranging from 1-10 mg/ml, for example. In this or any other embodiment herein, a composition comprising ammonium chloride may be used for in vitro or in vivo methods. In certain embodiments, ammonium chloride is present in a composition in an amount of about, at most about, or at least about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 mg/ml, or any range derivable therein. In particular embodiments, a composition may comprise from 5 to 6 mg/ml, such as 5.36 mg/ml, ammonium chloride. Ammonium chloride may be present in a composition in amounts greater than 10 mg/ml, or less than 1 mg/ml. Other composition amounts are described herein.
[0012] A composition comprising ammonium chloride may contact the HIV in vitro or in vivo more than once in a defined time period. Dosing and dosage timing are described further herein.
[0013] Also contemplated is a method of inactivating HIV in a patient comprising intravenously administering a composition comprising an effective amount of ammonium chloride to the patient. In certain embodiments, the patient does not suffer from chronic kidney disease. In certain embodiments, the patient suffers from chronic kidney disease. Skilled artisans will understand that additional care should be taken when treating a patient suffering from a chronic kidney disease using methods described herein. This is because patients with chronic kidney disease suffer from metabolic acidosis, which can be aggravated by ammonium chloride administration. Hyperkalemia and the increased possibility of heart paralysis, making it stop in diastole, are risks associated with ammonium chloride administration to a chronic kidney disease patient. Thus, some methods contemplate administration of a composition comprising ammonium chloride that occurs for a time period that is less than the time period of administration if the patient did not suffer from chronic kidney disease. For example, administration may take place for 5, 10, 15, 20, or 30 minutes, or any range derivable therein, as opposed to, e.g., a 24-hour long administration of a composition of the same concentration to a patient that does not suffer from chronic kidney disease. In some embodiments, a composition comprising a reduced amount of ammonium chloride is administered, wherein the reduced amount is an amount that is reduced compared to the amount that would be administered if the patient did not suffer from chronic kidney disease, but is still effective to inactivate HIV as explained herein.
[0014] In any embodiment herein, a composition comprising ammonium chloride may further comprise an additional agent, such as sodium chloride. The concentration of sodium chloride in a composition may range from, e.g., about 0.5% to about 1.5%. In some embodiments, the sodium chloride concentration is about, at most about, or at least about 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, or 1.5%. In some embodiments, the sodium chloride concentration is about 0.9%. Other optional agents are discussed herein.
[0015] Another aspect of the present invention contemplates a method of treating a patient suffering from AIDS comprising intravenously administering a composition comprising an effective amount of ammonium chloride to the patient.
[0016] The present invention also provides a method of delaying the onset of AIDS in an
[0017] HIV-positive patient comprising intravenously administering a composition comprising an effective amount of ammonium chloride to the patient, wherein the onset of AIDS is delayed as compared to if the patient had not been intravenously administered the composition. HIV-infected persons (that is, “HIV-positive persons”) are defined on clinical conditions associated with HIV infection and CD4+T lymphocyte counts. From a practical standpoint, the clinician views HIV infection as a spectrum of disorders ranging from primary infection with or without the acute HIV syndrome to the symptomatic infection state of advanced disease. The Centers for Disease Control and Prevention (CDC) in Atlanta, Ga., has established an authoritative definition for the diagnosis of AIDS, which informs a skilled artisan whether the onset of AIDS has occurred: in an HIV-positive individual, the CD4+T-cell count must be below 200 cells per cubic mm of blood, or there must be the clinical appearance of an initial AIDS-defining opportunistic infection, such as PCP (Pneumocystis Carinii Pneumonia), oral candidiasis (thrush), pulmonary tuberculosis, or invasive cervical carcinoma (cancer of the cervix in women). Methods of determining a patient's CD4+T-cell count are well-known in the art.
[0018] Persons of skill in the art are familiar with HIV inactivation. The Example below describes one method of assessing inactivation with respect to an in vitro sample. Another method of assessing HIV inactivation entails taking blood cultures followed by culturing in a T-Cell media and measuring the infectivity. An alternative method is to determine the virus copies that are present in the blood before and after the inactivation attempt or treatment in a periodic fashion (e.g., every 1-7 days). In a sample, about, at least about, or at most about 50%, 60%, 70%, 80%, 90%, 95%, 99%, or 100%, or any range derivable therein, of the virus may be inactivated. Methods of the invention also contemplate administering an effective amount of a composition comprising ammonium chloride, either in vitro to a sample or in vivo to a patient, until HIV is no longer detected.
[0019] The terms “contacted” and “exposed,” when applied to a cell or a sample, are used herein to describe the process by which a composition of the present invention is administered or delivered to a target cell or sample or is placed in direct juxtaposition with the target cell or sample. The terms “administered” and “delivered” are used interchangeably with “contacted” and “exposed.”
[0020] As used herein, the term “effective” (e.g., “an effective amount”) means adequate to accomplish a desired, expected, or intended result. For example, an “effective amount” may be an amount of a compound sufficient to produce a therapeutic benefit (e.g., effective to reproducibly inhibit decrease, reduce, or otherwise reduce the severity of an HIV infection). For any method comprising administration of an effective amount of a composition of the present invention to a patient, the method may alternatively comprise administration of a therapeutically effective amount of a composition, as that term is defined below.
[0021] As used herein, the term “patient” or “subject” refers to a living mammalian organism, such as a human, monkey, cow, sheep, goat, dogs, cat, mouse, rat, or guinea pig. In certain embodiments, the patient or subject is a primate. Non-limiting examples of human subjects are adults, juveniles, infants, and fetuses. A patient or subject may be further defined as one that suffers from chronic kidney disease. Alternatively, a patient or subject may be further defined as one that does not suffer from chronic kidney disease.
[0022] “Treatment” and “treating” as used herein refer to administration or application of a therapeutic agent, such as ammonium chloride, to a patient or performance of a procedure or modality on a patient for the purpose of obtaining a therapeutic benefit of a disease or health-related condition. For example, a patient infected with HIV may be subjected to a treatment comprising administration of a composition comprising ammonium chloride, as discussed herein, in order to mitigate HIV-related symptoms or to treat AIDS.
[0023] The term “therapeutic benefit” or “therapeutically effective amount” as used throughout this application refers to anything that promotes or enhances the well-being of the patient with respect to the medical treatment of a condition. This includes, but is not limited to, a reduction in the onset, frequency, duration, or severity of the signs or symptoms of a disease. For example, a therapeutically effective amount of a composition of the present invention may be an amount sufficient to provide a therapeutic benefit to an HIV-positive patient. Signs or symptoms of the initial stages of HIV infection include fever, swollen lymph nodes, sore throat, rash, muscle pain, malaise, and mouth and esophageal sores. AIDS, the final stage of HIV infection, may present with symptoms of various opportunistic infections, as is well-known in the art. Symptoms at this stage may include unexplained weight loss, recurring respiratory tract infections, prostatitis, skin rashes, and oral ulcerations. Methods of the claimed invention contemplate reducing the severity or duration of at least one HIV- or AIDS-related symptom comprising administering to an HIV-positive patient a composition comprising a therapeutically effective amount of ammonium chloride.
[0024] In any embodiment herein, the term “comprising” may be substituted with “consisting essentially of”or “consisting of.” For example, the present invention contemplates a method of inactivating at least 50% of HIV in a sample consisting essentially of contacting the sample with a composition comprising an effective amount of ammonium chloride. Also contemplated is a method of inactivating at least 50% of HIV in a sample consisting of contacting the sample with a composition comprising an effective amount of ammonium chloride. In such a method, it is intended that the method excludes other steps. Also contemplated is a method of inactivating at least 50% of HIV in a sample comprising contacting the sample with a composition consisting essentially of an effective amount of ammonium chloride. As another non-limiting example, also contemplated are methods of inactivating at least 50% of HIV in a sample consisting essentially of contacting the sample with a composition consisting of an effective amount of ammonium chloride. In such a method, it is intended that the composition excludes other ingredients. Another embodiment contemplates a method of inactivating at least 50% of HIV in a sample comprising contacting the sample with a composition consisting of an effective amount of ammonium chloride. In such a method, it is intended that the composition. excludes other ingredients. Another embodiment contemplates a method of inactivating at least 50% of HIV in a sample consisting of contacting the sample with a composition consisting of an effective amount of ammonium chloride. In such a method, it is intended that the method excludes other steps and that the composition excludes other ingredients. Also contemplated is a method of inactivating at least 50% of HIV in a sample consisting essentially of contacting the sample with a composition consisting essentially of an effective amount of ammonium chloride. Also contemplated is a method of inactivating at least 50% of HIV in a sample consisting of contacting the sample with a composition consisting essentially of an effective amount of ammonium chloride. In such a method, it is intended that the method excludes other steps. Other similar substitutions in any other embodiment discussed herein are also encompassed by the present invention. For those embodiments reciting “consisting essentially of,” it is noted that non-limiting examples of materials and steps that do not materially affect the basic and novel aspects of ammonium chloride include those that do not change the chemical structure of ammonium chloride, or those that do not decrease the effective amount of ammonium chloride that is administered either in vitro (e.g., that contacts a cell) or in vivo (e.g., that is intravenously administered). For those embodiments reciting “consisting of,” it is intended that other steps, components, or ingredients are excluded, as appropriate. It is further noted that any composition described herein may comprise, consist essentially of, or consist of sodium chloride or a pharmaceutically acceptable agent (e.g., carrier) in addition to an effective amount of ammonium chloride. Such carriers are described herein.
Ammonium Chloride
[0025] Ammonium chloride, a relatively inexpensive agent compared to most FDA-approved AIDS drugs, may be obtained from a variety of commercial sources. For example, ammonium chloride injection, USP may be obtained at a concentration of 100 mEq (5 mEq/ml) from HOSPIRA, Inc., Lake Forest, Ill. Ammonium chloride has been approved by the FDA for use in treating patients that exhibit alkalosis. See, e.g., the world wide web at <dailymed.nlm.nih.govidailymed/drugInfo.cfm?id=1343>. Patients receiving ammonium chloride should be constantly observed for symptoms of ammonia toxicity (e.g., pallor, sweating, retching, irregular breathing, bradycardia, cardiac arrhythmias, local and general twitching, tonic convulsions, or coma). It should be used with caution in patients with high total CO 2 and buffer base secondary to primary respiratory acidosis. Intravenous administration should be slow, such as a rate that does not exceed 70 mL/hour to avoid local irritation and toxic effects. When exposed to low temperatures, concentrated solutions of ammonium chloride may crystallize. If crystals are observed, the vial should be warmed to room temperature in a water bath prior to use. Overdosage of ammonium chloride may result in a serious degree of metabolic acidosis, disorientation, confusion, or coma. As an example of a suitable dosage, one may administer about 100 mEq of ammonium chloride in one liter of a 0.9% sodium chloride solution for about 24 hours. Should metabolic acidosis occur following overdosage, the administration of an alkalinizing solution such as sodium bicarbonate or sodium lactate may serve to correct the acidosis.
Pharmaceutical Formulations and Routes for Administration
[0026] Compositions comprising ammonium chloride that are administered to a patient infected with HIV are typically pharmaceutically or pharmacologically acceptable. A composition may comprise a pharmaceutically or pharmacologically acceptable agent in addition to ammonium chloride. The phrases “pharmaceutical or pharmacologically acceptable” refers to molecular entities and compositions that do not produce an adverse, allergic, or other untoward reaction when administered to a patient. The preparation of a pharmaceutical composition that contains ammonium chloride will be known to those of skill in the art in light of the present disclosure, as exemplified by Remington's Pharmaceutical Sciences, 18th Ed. Mack Printing Company, 1990. Moreover, for animal (e.g., human) administration, it will be understood that preparations should meet sterility, pyrogenicity, general safety, and purity standards as required by FDA Office of Biological Standards.
[0027] As used herein, “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, surfactants, antioxidants, preservatives (e.g., antibacterial agents, antifungal agents), isotonic agents, salts, preservatives, drugs, drug stabilizers, gels, binders, excipients, disintegration agents, dyes, such like materials and combinations thereof, as would be known to one of ordinary skill in the art (see, for example, Remington's Pharmaceutical Sciences , pp 1289-1329, 1990). Except insofar as any conventional carrier is incompatible with the active ingredient, its use in the therapeutic or pharmaceutical compositions discussed herein is contemplated.
[0028] A composition may comprise various antioxidants to retard oxidation of one or more components. Additionally, the prevention of the action of microorganisms can be brought about by preservatives such as various antibacterial and antifungal agents, including but not limited to parabens (e.g., methylparabens, propylparabens), chlorobutanol, phenol, sorbic acid, thimerosal, or combinations thereof.
[0029] Sterile injectable solutions may be prepared by incorporating the active compound (e.g., ammonium chloride) in the required amount in the appropriate solvent (e.g., water) with various of the other ingredients described herein, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium or the other ingredients. In the case of sterile powders for the preparation of sterile injectable solutions, suspensions, or emulsions, certain methods of preparation may include vacuum-drying or freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered liquid medium thereof. The liquid medium should be suitably buffered if necessary and the liquid diluent (e.g., water) first rendered isotonic prior to injection with sufficient saline or glucose.
[0030] The composition is preferably stable under the conditions of manufacture and storage, and preserved against the contaminating action of microorganisms, such as bacteria and fungi. It will be appreciated that endotoxin contamination should be kept minimally at a safe level, for example, less than 0.5 ng/mg protein.
[0031] The actual dosage amount of a composition of the present invention administered to a patient can be determined by physical and physiological factors such as body weight, severity of condition, previous or concurrent therapeutic interventions, idiopathy of the patient, and on the route of administration. The practitioner responsible for administration will, in any event, determine the concentration of active ingredient(s) in a composition and appropriate dose(s) for the individual patient. For example, dosing may be determined by following laboratory studies of blood gases to determine acidity and electrolyte status, or the composition of sodium, potassium, chloride, or CO 2 , as well as lymphocyte count and CD4-T cell counts over the treatment period to see the effective suppression or inactivation of the virus by the ammonium chloride composition.
[0032] When administering a composition comprising an effective amount or a therapeutically effective amount of ammonium chloride to a patient, administration is typically intravenously. The intravenous administration of ammonium chloride may, in certain embodiments, be 100 mEq of ammonium chloride vial (e.g., 20 ml) added to 1 liter of 0.9% saline solution. While dosing is discussed further below, ammonium chloride may be administered intravenously over a period of 24 hours, for example.
[0033] The dose can be repeated as needed as determined by those of ordinary skill in the art. Thus, in some embodiments set forth herein, a single dose is contemplated. In other embodiments, two or more doses are contemplated. Where more than one dose is administered to a patient, the time interval between doses can be any time interval as determined by those of ordinary skill in the art. For example, the time interval between doses may be about 1 hour to about 2 hours, about 2 hours to about 6 hours, about 6 hours to about 10 hours, about 10 hours to about 24 hours, about 1 day to about 2 days, about 1 week to about 2 weeks, or longer, or any time interval derivable within any of these recited ranges. In certain embodiments, it may be desirable to provide a continuous supply of a pharmaceutical composition to the patient.
[0034] In certain embodiments, a course of treatment will last 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90 days or more. As suggested above, within a single day (24-hour period), the patient may be given one or multiple administrations of the agent(s). Moreover, after a course of treatment, it is contemplated that there may be a period of time at which no other treatment is administered. This time period may last 1, 2, 3, 4, 5, 6, 7 days, or 1, 2, 3, 4, 5 weeks, or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 months or more, depending on the condition of the patient, such as their prognosis, strength, health, etc.
[0035] In particular embodiments, a composition may be administered 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 or more times, or every 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 hours, or 1, 2, 3, 4, 5, 6, or 7 days, or 1, 2, 3, 4, or 5 weeks, or 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 months or more, or any range or combination derivable therein.
[0036] It is specifically contemplated that any limitation discussed with respect to one embodiment of the invention may apply to any other embodiment of the invention. Furthermore, any composition of the invention may be used in any method of the invention, and any method of the invention may be used to produce or to utilize any composition of the invention.
[0037] The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.”
[0038] As used herein, “a” or “an” means one or more, unless clearly indicated otherwise.
[0039] Throughout this application, the term “about” is used to indicate that a value includes the standard deviation of error for the device and/or method being employed to determine the value.
EXAMPLE 1
[0040] Antiviral Study of Ammonium Chloride Against HIV Type 1
[0041] Composition Tested: A 20 mL vial of ammonium chloride (100 mEq/5 mL) was dissolved into a 1 liter bag of 0.9% sodium chloride injection USP (9 g/L sodium chloride; osmolarity of 308 mOsmol/L; 154 mEq/L sodium; 154 mEq/L chloride). The contents of the bag were transferred to a sterile glass bottle. The solution was equilibrated to room temperature prior to use.
[0042] Virus: human immunodeficiency virus (HIV) Type I, strain HTLV-III B , was obtained from Advanced Biotechnologies, Inc., Columbia, Md. Stock virus was prepared by collecting the supernatant culture fluid from infected culture cells. The cells were disrupted and cell debris removed by centrifugation at approximately 2200 RPM for ten minutes at room temperature. The supernatant was removed, aliquoted, and the high titer stock virus was stored at ≦−70° C. until the day of use. On the day of use, an aliquot of stock virus was removed, thawed, and maintained at a refrigerated temperature until used in the assay. The stock virus culture was adjusted to contain 5% fetal bovine serum as the organic soil lead. The stock virus tested demonstrated cytopathic effects (CPE) typical of HIV on MT-2 cells.
[0043] Test Cultures: MT-2 cells (human T-cell leukemia cells) were obtained through the AIDS Research and Reference Reagent Program, Division of AIDS, NIAID, NIH from Dr. Douglas Richman. Cultures were maintained and used in suspension in tissue culture labware at 36-38° C. in a humidified atmosphere of 5-7% CO 2 .
[0044] Test Medium: The test medium used for the assay was RPMI 1640 supplemented with 10% (v/v) heat-inactivated fetal bovine serum (FBS). The medium was also supplemented with 2.0 mM L-glutamine and 50 μg/mL gentamicin.
[0000]
TABLE 1
Parameters tested for virucidal efficacy assay.
Test or Control
Dilutions Assayed
Cultures per
Total
Group
(log 10 )
Dilution
Cultures
Cell Control
N/A
4
4/group
Virus Control
−2, −3, −4, −5, −6, −7
4
24
Sample lot + virus
−2, −3, −4, −5, −6, −7
4
24
(Test composition)
Cytotoxicity
−2, −3, −4
4
12
Control
Neutralization
−2, −3, −4
4
12
Control
[0045] Treatment of Virus Suspension: A 1.80 mL aliquot of the test substance was dispensed into a sterile tube and mixed with a 0.2 mL aliquot of the stock virus suspension. The mixture was vortex mixed for 10 seconds and held for the remainder of the specified exposure time at 37.0° C. The exposure time was ten minutes. Following the exposure time, a 0.1 mL aliquot was removed from the tube and the mixture was immediately titered by 10-fold serial dilution (0.1 mL+0.9 mL test medium) and assayed for the presence of virus in MT-2 cells. To decrease the test substance cytotoxicity, the first dilution was made in FBS with the remaining dilutions in test medium.
[0046] Treatment of Virus Control: A 0.2 mL aliquot of stock virus suspension was exposed to a 1.80 mL aliquot of test medium, in lieu of test substance, and treated as previously described. Following the exposure time, a 0.1 mL aliquot was removed from the tube and the mixture was immediately titered by 10-fold serial dilution (0.1 mL+0.9 mL test medium) and assayed for the presence of virus in MT-2 cells. All controls employed the FBS neutralizer as described in the Treatment of Virus Suspension section above. The virus control titer was used as a baseline to compare the percent and log reductions of the test parameter following exposure to the test substance.
[0047] Cytotoxicity Control: A 1.80 mL aliquot of the test substance was mixed with a 0.2 mL aliquot of test medium containing the BSA organic soil load, in lieu of virus, and treated as previously described. The cytotoxicity control was held for the ten minute exposure time. Following the exposure time, a 0.2 mL aliquot was removed from the tube and the mixture was immediately titered by 10-fold serial dilution (0.2 mL+1.8 mL test medium) in MT-2 cells. The cytotoxicity of the MT-2 cell cultures was scored at the same time as virus-test substance and virus control cultures. Cytotoxicity was graded on the basis of cell viability as determined microscopically. Cellular alterations due to toxicity were graded and reported as toxic (T) if greater than or equal to 50% of the monolayer was affected.
[0048] Neutralization Control: Each cytotoxicity control mixture (above) was challenged with low titer stock virus to determine the dilution(s) of test substance at which virucidal activity, if any, was retained. Dilutions that showed virucidal activity were not considered in determining reduction of the virus by the test substance. Using the cytotoxicity control dilutions prepared above, an additional set of indicator cell cultures was inoculated with a 0.2 mL aliquot of each dilution in quadruplicate. A 0.02 mL aliquot of low titer stock virus was inoculated into each cell culture well and the indicator cell cultures were incubated along with the test and virus control plates.
[0049] Infectivity Assay: The MT-2 cell line, which exhibits CPE in the presence of HIV-1, was used as the indicator cell line in the infectivity assays. Cells in the multiwall culture dishes were inoculated in quadruplicate with 0.2 mL of the dilutions prepared from test and control groups. Uninfected indicator cell cultures (cell controls) were inoculated with test medium alone. The cultures were incubated at 36-38° C. in a humidified atmosphere of 5-7% CO 2 in sterile disposable cell culture labware. The cultures were scored periodically for eight days for the absence or presence of CPE, cytotoxicity, and for viability.
[0050] Data analysis: Viral and cytotoxicity titers are expressed as −log 10 of the 50 percent titration endpoint for infectivity (TCID 50 ) or cytotoxicity (TCD 50 ), respectively, as calculated by the method of Spearman Karber:
[0000]
Log
of
1
st
dilution
inoculated
-
[
(
(
Sum
of
%
mortality
at
each
dilution
100
)
-
0.5
)
×
(
logarithm
of
dilution
)
]
Calculation of Percent (%) Reduction:
[0051]
%
Reduction
=
1
-
[
TCID
50
test
TCID
50
virus
control
]
×
100
Calculation of Log Reduction:
[0052] TCID 50 of the virus control—TCID 50 of the test substance=Log reduction Study Acceptance Criteria: A valid test required the following: (1) that stock virus be recovered from the virus control; (2) that the cell controls be negative for virus; and (3) that negative cultures are viable.
[0053] Results: Test substance cytotoxicity was not observed at any dilution tested (≦1.5 log 10 ). The neutralization control demonstrated that the test substance was neutralized at ≦1.5 log 10 . The titer of the virus control was 6.0 log 10 . Following exposure, test virus infectivity was detected in the virus-test substance mixture at 5.0 log 10 .
[0054] Using a composition of 100 mEq/5 mL ammonium chloride (20 mL) dissolved in 1 liter of 0.9% Sodium Chloride Injection USP in the presence of 5% fetal bovine serum, a 90% reduction in viral titer was observed following a ten minute exposure time at 37° C. of the composition to HIV Type-1 as compared to the titer of the virus control. The log reduction in viral titer was 1.0 log 10 .
[0000]
TABLE 2
Assay results.
Test: HIV Type
1 + Ammonium
Virus
Chloride
Cytotoxicity
Neutralization
Dilution
Control
(100 mEq/5 mL)
Control
Control
Cell Control
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
10 −2
+ + + +
+ + + +
0 0 0 0
+ + + +
10 −3
+ + + +
+ + + +
0 0 0 0
+ + + +
10 −4
+ + + +
+ + + +
0 0 0 0
+ + + +
10 −5
+ + + +
0 0 + +
NT
NT
10 −6
+ + 0 0
0 0 0 0
NT
NT
10 −7
0 0 0 0
0 0 0 0
NT
NT
TCID 50 /
10 6.0
10 5.0
≦10 15 *
Neutralized at
0.2 mL
a TCID 50
of ≦1.5 Log 10
Percent
NA
90.0%
NA
NA
Reduction
Log 10
NA
1.0 Log 10
NA
NA
Reduction
+ = Positive for the presence of test virus
0 = No test virus recovered and/or no cytotoxicity present
NA = Not applicable
NT = Not tested
*= Cytotoxicity results are reported as TCD 50 /0.2 mL
[0055] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
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The present invention pertains to methods of inactivating human immunodeficiency virus (HIV), both in vitro and in vivo. Such methods also relate to treating HIV-related symptoms and the treatment of acquired immune deficiency syndrome in patients. Methods typically employ administering a composition comprising ammonium chloride such that HIV is inactivated.
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FIELD OF THE INVENTION
[0001] The present invention relates to a process for preparing a Cu damascene interconnection, particularly a process for preparing a Cu damascene interconnection with an improved yield.
BACKGROUND OF THE INVENTION
[0002] In the damascene of copper in a low dielectric material, a copper line structure is formed by forming trenches in a low dielectric layer by using an active ionic etching, depositing copper on the whole surface (including filling the trench with copper), and using a chemical mechanical polishing (CMP) to polish off the copper on the surface and leaving copper in the trenches.
[0003] A photoresist is used as a mask layer when the active ionic etching is carried out. In order to protect the organic low dielectric layer from damage during the stripping of the photoresist mask layer, a passivation layer is required between the photoresist and the organic low dielectric layer [J. M. Neirynck, R. J. Gutmann, and S. P. Murarka, J. Electrochem. Soc., 1602, (1999); D. T. Price, R. J. Gutmann, and S. P. Murarka, Thin Solid Films, 308-309, 523 (1997)]. However, due to a poor adhesion between the passivation layer and the low dielectric layer, the deposited copper layer is torn off from the surface and the trenches during the CMP process. As a result, a copper damascene interconnection can not be completed.
SUMMARY OF THE INVENTION
[0004] The present invention provides a process for preparing a Cu damascene interconnection, which comprises forming a low-K dielectric layer on a substrate; forming a passivation layer on said low-K dielectric layer; forming a plurality of trenches on said low-K dielectric layer/passivation layer; forming a pad oxidation layer on the inner walls of each of said plurality of trenches; forming a barrier metal layer on said pad oxidation layer; depositing copper on the resulting structure; and chemical mechanical polishing said copper until said passivation layer is exposed, thereby forming a Cu damascene interconnection on said low-K dielectric layer, characterized in subjecting said passivation layer/low-K dielectric layer with a N 2 O plasma annealing prior to the formation of said plurality of trenches.
[0005] The present invention uses said N 2 O plasma annealing to improve the yield of the process for preparing a Cu damascene interconnection.
[0006] Preferably, said N 2 O plasma annealing uses the following conditions: N 2 O flow rate 50˜1000 sccm, pressure 10˜1000 mTorr, temperature of plate 20˜450° C., radio frequency power 50˜1000 W, and processing time 1˜100 minutes.
[0007] Preferably, said low-K dielectric layer is hydrogen silsesquiuxane or methyl silsesquioxane.
[0008] Preferably, said passivation layer is SiO 2 or SiNx, wherein 0<x<1.4. More preferably, said passivation layer is SiO 2 , particularly a SiO 2 deposited by a chemical vapor phase deposition (CVD).
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIGS. 1 ( a ) to 1 ( e ) show the schematic sectional view of the device in the essential steps for preparing a Cu damascene interconnection according to the present invention;
[0010] [0010]FIG. 2 shows the structural layout of a Cu damascene interconnection;
[0011] FIGS. 3 ( a ) to 3 ( c ) separately show the optical microscopic photos of a Cu damascene interconnection prepared according to the present invention, wherein FIG. 3( a ) is 200X, FIG. 3( b ) is 500X, and FIG. 3( c ) is 1000X;
[0012] FIGS. 4 ( a ) to 4 ( c ) separately show the electron microscopic photos of a Cu damascene interconnection prepared by a conventional process, wherein FIG. 4( a ) is 5000X, FIG. 4( b ) is 10000X, and FIG. 4( c ) is 5000X; and
[0013] [0013]FIG. 5 is a plot of C/Si count ratio vs. sputter time (sec) in a secondary ion mass spectrum (SIMS) analysis of a 500 Å SiO 2 /MSQ with/without N 2 O plasma annealing, wherein the dash line represents the sample with N 2 O plasma annealing and the solid line represents the sample without N 2 O plasma annealing.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention proposes using a CVD SiO 2 treated by a N 2 O plasma annealing as a passivation layer in a Cu damascene interconnection structure. The CVD SiO 2 formed on the surface of the organic low-K dielectric layer (e.g. hydrogen silsesquiuxane or methyl silsesquioxane (MSQ)) will form a re-bonding with the organic low-K dielectric layer during the N 2 O plasma annealing treatment, thereby increasing the adhesion therebetween. As a result, the lamination can withstand the tearing force generated during the subsequent CMP on the copper metal layer.
[0015] In the following text, a low-K (˜2.8) dielectric MSQ was used as an example. Such a MSQ was covered by a SiO 2 formed by a chemical vapor phase deposition (CVD), and then was subjected to a N 2 O plasma annealing treatment to form a passivation layer, or just simply covered by a simple SiNx as a passivation layer. After the CMP, a planar evaluation on the resulting copper lines whether they remain intact in the trenches of the organic low-K dielectric layer or not was used to verify the improvement and applicability of the present invention.
[0016] According to a preferred embodiment of the present invention, a damascene structure of copper/low-K dielectric layer was prepared by the following steps, as shown in FIGS. 1 ( a ) to 1 ( e ).
[0017] spin-coating an organic low-K dielectric layer (MSQ) (thickness 4000 Å) on a wet oxide layer 100 ;
[0018] covering said MSQ layer with a layer of SiO 2 10 (thickness 500 Å) as a passivation layer by plasma-enhanced chemical vapor phase deposition [T. Rukuda, T. Ohshima, H. Aoki, H. Maruyama, H. Miyazaki, N. Konishi, S. Fukada, T. Yunogami, S. Hotta, S. Maekawa, K. Hinode, K. Nojiri, T. Tokunaga, and N. Kobayashi, in Tech. Dig. IEEE Int. Electron Devices Meeting. (IEDM), 619 (1999)], wherein tetraethoxysilane (TEOS) was used as a precursor of said SiO 2 ;
[0019] performing said N 2 O plasma annealing in a parallel plate type plasma enhanced deposition device under the following working conditions: N 2 O gas flow rate 200 sccm, temperature of the upper/lower plates 250/300° C., radio frequency power 200 W, internal pressure of the reaction chamber 200 mTorr, and processing time 15 minutes (FIG. 1( a ));
[0020] spin coating a photoresist on the passivation layer 10 , imagewise exposing and developing the photoresist to form a patterned photoresist 20 , and forming a plurality of trenches in the MSQ layer by active ionic etching said passivation layer 10 and the MSQ layer by using said patterned photoresist as a mask layer (FIG. 1( b ));
[0021] prior to the removal of said photomask, using a selective liquid phase deposition to grow SiO 2 (300 Å) on the side walls and the bottoms of said trenches as a pad oxidation layer 30 (C. F. Yeh, Y. C. Lee, Y. C. Su, K. H. Wu, and C. H. Lin, “Novel Sidewall Capping for Degradation-Free Damascene Trenches of Low-Permitivity Methylsilsesquioxane”, Jpn. J. Appl. Phys., Vol.39, Part 2, p.354-p.356, 2000; U.S. Pat. No. 6,251,753B1), thereby protecting said side walls and the bottoms from being damaged by the subsequent oxygen plasma treatment; stripping the patterned photoresist by using oxygen plasma ashing, and cleaning in H 2 SO 4 /H 2 O 2 solution (H 2 SO 4 /H 2 O 2 =3:1) afterward, thereby completely removing said photomask (FIG. 1( c ));
[0022] vacuum sputtering TiN (300 Å) as a barrier metal layer 40 and Cu (10000 Å) (FIG. 1( d ));
[0023] using a two-stage chemical mechanical polishing (CMP) process to polish off Cu and TiN (barrier metal layer 40 ) until said passivation layer 10 was exposed (the detailed operation conditions of the CMP process is listed in Table 1), and immediately covering the exposed surface with SiNx to prevent oxidation of Cu, thereby completing the preparation of the Cu damascene interconnection (FIG. 1( e )).
TABLE 1 Removal Rate Function Composition of Slurry (nm/min) Selectivity Stage1 Cu removal HNO 3 3 wt. % 600 — citric acid 10 −3 M Al 2 O 3 3 wt. % Stage2 TiN removal Bayer's 456417F9 168 6.7 (to Cu) 50 vol. % H 2 O 2 3 wt. %*
[0024] Said passivation layer 10 has a function of preventing said organic low-K dielectric layer MSQ from being damaged by said oxygen plasma treatment.
[0025] A Cu damascene interconnection with a structure layout as shown in FIG. 2 was prepared according to by the abovementioned preferred embodiment of the present invention, wherein the middle portion is a Cu line 11 with length×width (L×W)=500 μm×2 μm, and the two sides are Cu line pads 12 . A net-shaped pad was particularly used for avoiding the occurrence of a dishing effect during the CMP process. Furthermore, a net-shaped Cu pad was also be used to observe the adhesion between copper and the low-K dielectric layer MSQ in this portion during the CMP process as to whether the copper is intact in the trenches. As shown in FIGS. 3 ( a ) to 3 ( c ) (( a ) 200X, ( b ) 500X, and ( c ) 1000X), the Cu damascene interconnection prepared according to the present invention show no peeling off between the copper and the organic low-K dielectric layer MSQ after the CMP process, and the copper remains in the trench intact.
[0026] The N 2 O-plasma-annealing treated passivation layer 10 was replaced by a SiNx layer in a control example. As shown in the scanning electron microscopy (SEM) photos of FIGS. 4 ( a )- 4 ( c ) (( a ) 5000X, ( b ) 10000X, ( c ) 5000X), the copper is pulled out from the trenches completely (as shown in FIGS. 4 ( a ) and ( b )) after the CMP process in the control example, and even the organic low-K dielectric layer MSQ is pulled out together (as shown in FIG. 4( c )). This could be resulted from a poor adhesion between the SiNx and the organic low-K dielectric layer MSQ.
[0027] On the other hand, the passivation layer 10 of the present invention, which is SiO 2 formed by a chemical vapor phase deposition and subjected to a N 2 O plasma annealing, is believed having a re-bonding with the surface of the organic low-K dielectric layer MSQ, thereby increasing the adhesion therebetween.
[0028] In order to understand whether the N 2 O plasma annealing will cause a re-bonding between the SiO 2 deposited by a chemical vapor phase deposition and the surface of said organic low-K dielectric layer, a secondary ion mass spectrum (SIMS) analysis was carried out on said organic low-K dielectric layer (MSQ) covered with the chemical vapor phase deposited SiO 2 , wherein comparisons were made between specimens with or without the N 2 O plasma annealing. The results are shown in FIG. 5. It can be seen from FIG. 5 that, after the N 2 O plasma annealing, an oxidation seems to occur on the surface of the organic low-K dielectric layer. The profile of C/Si count ratio vs. sputter time of the sample with N 2 O plasma annealing shifts to the right, indicating that there is a re-bonding on the surface of the organic low-K dielectric layer in the sample with N 2 O plasma annealing. Therefore, it might be concluded that the N 2 O plasma annealing can increase the adhesion between the chemical-vapor-phase-deposited SiO 2 and the organic low-K dielectric layer.
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The present invention discloses a technique of enhancing adhesion between a passivation layer and a low-K dielectric layer, in which a SiO 2 layer as the passivation formed on the low-K dielectric layer is subjected to N2O plasma annealing. This technique is useful in improving the yield of a process for preparing Cu damascene interconnection.
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RELATED APPLICATION
This application is a division of application Ser. No. 09/201,367 filed on Nov. 30, 1998, now U.S. Pat. No. 6,030,471 issued Feb. 29, 2000.
FIELD OF THE INVENTION
The present invention relates, generally, to wheels for use in overhead crane assemblies, pulley systems, or the like. More particularly, the present invention concerns crane wheels which travel along a rail in an overhead crane assembly. Specifically, the present invention pertains to case hardened crane wheels with improved wear characteristics and toughness.
BACKGROUND OF THE INVENTION
Overhead cranes which travel on wheels along spaced apart, generally parallel rails, are subject to the continuous problem of crane wheel wear and failure. In such overhead cranes, wheels roll along a rail surface such that a portion of a crane wheel comes into contact with the rail surface thereby subjecting that portion of the crane wheel to wear.
A typical prior art crane wheel 20 is shown in FIGS. 1 and 2. The crane wheel 20 includes a hub 22 which surrounds an axis of rotation 24 of the crane wheel 20 . The hub 22 is part of a radially inner portion 26 which consists of a body or core material 28 of the wheel 20 . The crane wheel 20 further includes a radially outer portion 30 which includes a working tread surface 32 and opposing outer flanges 34 , 36 which have respective inner surfaces 38 , 40 . The working tread surface 32 and at least portions of the flange inner surfaces 38 , 40 make up a wear area 42 of the crane wheel 20 .
As can be appreciated by those skilled in the art, certain portions of a crane wheel need different physical characteristics as compared to other portions of the crane wheel. The different physical properties are necessary because of the different conditions encountered by the different parts of the crane wheel as the crane wheel is in service. The wear area that engages a rail of an overhead crane must be resistant to wear. Thus, this portion of the wheel should be hardened. The hub of the wheel may be machined after heat treating of the wheel for the reception of an axle and of various bearing members in a crane assembly. Thus, this portion of the wheel should preferably remain machinable after heat treating of the wheel. As a result, for these types of wheels, processes have been used in an attempt to harden areas subjected to wear while attempting to maintain other areas of the wheel ductile or, as-forged.
Two prior processes used to harden wear surfaces of a crane wheel and which are capable of providing the necessary surface hardness required to support and guide heavy crane wheel loads, are generally known as the salt bath process and the gas carburizing process. The salt bath process involves heating the surface temperature of a crane wheel to roughly about 1650° F. by immersing the entire wheel or part of the wheel into a molten salt bath. When immersing only part of the wheel at any given time, the wheel is usually mounted on a rotating member such that the flanges, working tread surface and part of the body come into contact with the salt bath as the wheel is rotated. The heating process takes from one to three hours depending on the size of the crane wheel. Once the desired temperature is reached, the wheel is removed from the molten salt bath and transported to a quench bath where the wheel may be spin quenched in a manner similar to heating the wheel as outlined above. Alternatively, the entire wheel may be submerged in the quench bath.
The gas carburizing process involves securing a crane wheel in place in a gas tight box. Air in the box is evacuated and replaced with a carbon rich gas. The box is then heated to roughly about 1650° F. for six to 36 hours, depending on the size of the wheel and the desired case depth. The elevated temperature allows the crane wheel surface to accept carbon from the gas. The wheel obtains a high carbon level on the outside surfaces, including the wear area, which surfaces can then be exposed to a thermal transformation process in order to obtain high surface hardness at the exposed surfaces.
FIGS. 1 and 2 represent prior art crane wheels created according to prior methods such as those just described. As can be observed from the shaded-in portions 39 , of the crane wheels 20 , the flanges 34 , 36 are completely through hardened. As will be further explained below, these through-hardened portions are extremely brittle and subject to possible failure upon adverse impact during use.
SUMMARY OF THE INVENTION
As generally known, to heat treat and harden steel, the material must be heated beyond its critical or transformation temperature. Once past the critical or transformation temperature, the material becomes austenite. A rapid quench of the austenite material creates a hardened material called martensite. Although this hardened material is highly resistant to wear, this hardened material is generally very brittle. As will be further explained below, fully hardened or through hardened flanges of a crane wheel, although somewhat resistant to wear, are typically brittle and subject to possible failure during use in the field.
The prior salt bath process completely through hardens the flange areas of a crane wheel. Meaning, not only are the wear surfaces of the flanges hardened, the entire area of each flange is hardened. As noted, a completely through hardened flange of a crane wheel makes the flange extremely brittle and reduces the overall impact strength of the flange such that the wheel is more susceptible to failure. Thermal cracking frequently occurs in flange areas of a wheel when such flange areas are through hardened. Typically, this results in large portions of the flange area separating from the wheel rendering the wheel inoperable, and creating a dangerous situation where large portions of the wheel may fall on equipment or unsuspecting persons located below an overhead crane.
A phenomenon known as radical cracking occurs when raw material does not meet the material cleanliness specifications when a wheel is formed or when a wheel is unevenly heated during a hardening process. With the large volume of material being hardened in a salt bath process, any slag inclusions in the material or uneven heating within the core of the wheel will create internal stresses that make the wheel prone to radial crack failure. Only a slight deviation from the material cleanliness specification or slightly uneven heating makes a wheel highly susceptible to radial crack failure rendering the salt bath process less than desirable in some instances.
Another problem with the salt bath process is explained with reference to hardening a typical 500-pound crane wheel. To completely transform the wear areas of such a crane wheel using the salt bath method, the wheel must be heated generally for three hours to reach a temperature of around 1650° F. Because of the extensive time needed to reach the transformation temperature, pressures for increased productivity may result in some necessary parts of a crane wheel to not reach the proper transformation temperature. This causes what is generally known as a “butterfly” of soft material in portions of the wheel. This weakens the overall wheel structure and premature field failures may occur.
The prior carburizing process is rarely used today because of the amount of time and degree of temperature needed to obtain hardened surfaces. For example, for a typical 500-pound crane wheel, to completely transform all the wear areas of a crane wheel, the crane wheel must be heated generally for 30 hours to reach a temperature of around 1650-1750° F. This will provide a hardened surface but, for many crane wheels, the case depth is still insufficient to effectively resist wear. As with the salt bath process, and even more so because of the longer periods of heating time, production requirements may result in some crane wheels being heated at improper temperatures for too short of time. This causes shallow and irregular heat patterns which, in turn, provide improper or unsatisfactory wear characteristics. Additionally, another problem with the slow heating process of the carburizing process is that the slow heating process causes heat to migrate into other portions of the wheel causing uneven stresses, distortion and possibly cracking.
What is needed is a wheel that has excellent wear characteristics and toughness. What is also needed is a new process to harden only desired portions of a wheel in an easier and less time consuming manner. What is also needed is a process which provides localized heating to selected portions of a wheel thereby preventing undesired areas of the wheel from heating and eventually hardening. What is further needed is a wheel that is capable of meeting industry standards with respect to wear resistance while at the same time reducing or preventing the problems associated with through hardened flanges.
In one embodiment of the present invention, the radially outer portion includes a hardened portion which includes the wear area and which extends beneath the working tread surface and into the outer flange such that the outer flange is not completely through hardened.
Preferably, the radially outer portion of the wheel includes a second outer flange opposite the first outer flange, the second outer flange including a surface and the wear area including at least a portion of this surface. The hardened portion is of a substantially parabolic shape extending beneath the working tread surface and into portions of each flange such that each flange is not completely through hardened. Further, in the preferred embodiment of the invention, approximately two-thirds to approximately three-fourths of each flange is hardened into a range of, preferably, approximately 58-62 Rockwell-C.
The present invention also includes a method for surface hardening a wear area of a wheel. An induction heater heats the wear area of the wheel while the wheel is rotating about its axis. The temperature of the wear area of the wheel is monitored until such time as the temperature is at least greater than the critical temperature of the wheel. After the critical temperature is reached, the wheel is submerged in a quench bath, preferably, an agitated quench bath. While in the quench bath, the wear area of the wheel is sprayed with a quenching agent. Preferably, the wheel is rotated about its axis while the wheel is submerged in the quench bath.
Preferably, after the wheel has been quenched, the wheel is removed from the quench bath and then the wheel undergoes a tempering process where the wear area is again heated, preferably, with the same induction heat as previously used. During the tempering process, the crane wheel rotates about its axis. As before, the temperature of the wear area is monitored and, once a predetermined temperature is reached, the wheel is cooled in, preferably, the same quench bath as previously used.
Accordingly, it is a feature of the present invention to provide a wheel with improved toughness and wear resistance by selectively hardening wear portions of the wheel.
Another feature of the present invention is to reduce the volume of material transformed in a hardening process for a wheel thereby decreasing the likelihood of the wheel from exhibiting thermal cracking and/or radial crack failure.
Yet another feature of the present invention is to provide hardened wheels which exhibit superior toughness as compared to prior hardened wheels, while at the same time, maintaining a ductile core to improve impact strength, all of which reduces field and manufacturing related failures.
Still another feature of the present invention is to provide a wheel with improved wear characteristics and toughness while reducing production costs and lead time.
A further feature of the present invention is to provide a wheel having a flange which is part of a wear area of the wheel such that the flange is hardened in a way whereby the entire flange area is not completely through hardened.
Yet a further feature of the present invention is to improve the uniformity of case hardness in a wheel thereby providing a more uniform wear surface hardness and more uniform subsurface stresses which lead to uniform compressive stresses which improves the reliable working life of the wheel.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-2 show respective prior art crane wheels having hardened portions as created by prior art methods.
FIG. 3 is an assembly view of an induction hardening system showing a crane wheel positioned to undergo an induction hardening process according to the present invention.
FIG. 4 is a partial perspective side view of the induction hardening system of FIG. 3 showing the relative positions of the crane wheel during certain steps of the induction hardening process according to the present invention.
FIG. 5 is a top view of the induction hardening system and crane wheel of FIG. 4 .
FIGS. 6-10 are partial cross-sectional side views of the induction hardening system of FIG. 3 showing, respectively, various positions of the crane wheel with respect to an induction heater and a quench tank as the crane wheel undergoes the induction hardening process according to the present invention.
FIG. 11 is a top view of a typical crane wheel subject to a hardening process according to the present invention.
FIG. 12 is a perspective, partially cut away, view of the crane wheel of FIG. 11 .
FIG. 13 shows a crane wheel with a hardened portion according to the present invention.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Illustrated in FIGS. 11 and 12 is a typical forged carbon steel crane wheel 120 subject to a hardening process according to the present invention. Except as described below, the parts of the wheel 120 are the same as those of the prior art wheel 20 , and common elements have been given the same reference numerals.
As will be apparent, although the crane wheel is shown as having two opposing flanges 34 , 36 having substantially the same dimensions, other wheels are capable of benefiting from the principles of the invention described herein. Such wheels may include opposing flanges with one flange being thicker than the other flange; or such wheels may have only a single flange; or such wheels may be flangeless. Also, other non-crane wheels which require hardened surfaces are also capable of benefiting from the principles of the invention described herein. Such wheels may be used in various pulley systems, material handling systems, or even in automobiles or heavy machinery. Additionally, wheels made from all types of metals which require hardened surfaces are capable of benefiting from the principles of the present invention.
FIG. 3 shows an induction hardening system or facility 44 used for hardening a crane wheel 120 with a hardening process according to the present invention. The crane wheel 120 is secured to a mounting fixture 46 which is part of a retractable rotating (represented by arrows 50 , 52 ) device 48 . The device 48 includes a piston rod 47 and device 48 may be a hydraulic lifting mechanism or the like. As shown in FIG. 3, directly below the crane wheel 120 , is a quench tank 54 which contains a quenching liquid 55 . The quenching liquid 55 is a mixture of water and a quenching agent or product. The quenching liquid 55 generally has about a 90-96 percent water concentration. Although many quenching agents are available on the market, known to those skilled in the art, Quenchant, available from Tenaxol, Inc. of Milwaukee, Wisconsin, and sold under the trademark UCON A registered to Union Carbide, works well with the principles of the present invention.
The quench tank 54 is generally square or rectangular in shape, but can be of many different shapes. The quench tank 54 has an inside wall surface 56 and an outside wall surface 58 . A hollow tubular ring 60 (see FIGS. 3-5) is positioned within the interior 62 of quenching tank 54 below the quenching liquid surface 64 . The ring 60 may be secured to the interior wall 56 or positioned within the tank 54 in any number of ways, such as, by welding the ring 60 to the inside surface 56 of the tank 54 or by positioning the ring 60 inside the tank 54 through the use of a support structure (not shown). The ring 60 includes circumferentially spaced apart nozzles 66 , the function of which will be explained below.
Pump 68 is attached to the outside wall surface 58 of tank 54 . Pump 68 includes two pipes 70 , 72 . One pipe 70 extends through outside wall surface 58 and connects to the hollow ring 60 . The other pipe 72 extends through outside wall surface 58 into the quenching liquid 55 . The pump 68 circulates the quenching liquid 55 from the quenching tank 54 to the nozzles 66 in the ring 60 such that the quenching liquid 55 is expelled through nozzles 66 , the purpose of which will be further explained below.
Bracket mounting fixture 74 (FIG. 3) is attached to the outside wall surface 58 of tank 54 . A temperature measuring device 76 , such as an infra-red scanner, is secured to bracket 74 . The function of temperature measuring device 76 will be explained below. There are many infra-red scanner systems, known to those skilled in the art, capable for use according to the principles of the present invention, but an infra-red scanner sold by Williamson Corporation of Concord, Mass. under the model number 8100LT is particularly well-suited for use with the present invention.
An induction hardening device 78 is located adjacent to quench tank 54 . The hardening device 78 includes a control system 80 , electrical lines 82 , and an induction coil 84 . The infra-red scanner 76 , pump 68 , and retractable rotating device 48 are electrically connected to the control system 80 of the induction hardening device 78 . The induction coil 84 is retractably mounted, as represented by arrow 51 shown in FIG. 6, to the hardening device 78 . The induction coil 84 is generally made of a single loop square that is capable of heating a wide range of surfaces. The induction coil may be formed to have a radius that matches or substantially matches the radius of the surface to be heated. The induction coil may be made from various sized, single-loop squares, depending on the size and shape of the surface to be heated. Although standard induction coils known to those skilled in the art may be suitable for use according to the present invention, an induction coil according to the present invention sold by Pillar Industries of Menomonee Falls, Wis. is particularly well-suited for the principles of the present invention.
With reference to FIGS. 3-10, the method according to the present invention will be explained, the method carried out by the induction hardening system 44 of FIG. 3 . FIG. 4 shows the crane wheel 120 in two positions. The first or upper position, shown in phantom, is where the crane wheel 120 is originally located with respect to the quench tank 54 and induction coil 84 (see FIG. 6) prior to being submerged in the tank 54 . In the second or lower position, the crane wheel 120 is submerged in the tank 54 and the wear area 42 of the crane wheel 120 is sprayed with the quenching liquid 55 via pump 68 as the crane wheel 120 is rotated about its axis. FIG. 5 is a top view of FIG. 4 also showing the wear area 42 of the crane wheel 120 being sprayed with the quenching liquid 55 . The process of moving and the purpose for moving the crane wheel 120 from the first position to the second position will be explained in detail with particular reference to FIGS. 6-10, in conjunction with reference to FIGS. 3-4.
FIG. 6 shows crane wheel 120 in the upper position or in an uppermost location as determined by device 48 . Induction coil 84 is shown retracted from the wheel 120 . FIG. 6 represents the location of the referenced parts prior to the beginning of the hardening process.
FIG. 7 shows the wear area 42 of the crane wheel 120 being heated. Induction coil 84 is positioned relative to the wear area 42 to heat the wear area 42 . The partially shaded portion 43 represents that part of the wheel 120 being heated by the induction coil 84 . Wheel 120 rotates about its axis 24 , represented by arrow 52 , preferably at approximately 60 revolutions per minute, as the induction coil 84 heats the wear area 42 . The induction coil 84 creates a hot spot in the wheel 120 under the induction coil 84 . Spinning the crane wheel 120 past the induction coil 84 continuously moves the hot spot under the coil 84 around the working tread surface 32 . This allows the heat to conduct into the wheel 120 and heats more metal, allowing for more complete metal transformation and produces a more uniform heating. Spin hardening the wheel 120 helps ensure that the surfaces 32 , 38 , 40 of the wear area 42 receive approximately the same amount of heat in the same amount of time. This produces a more uniform hardened surface as compared to prior methods, thereby producing a hardened surface better suited for uniform wear and, thereby, also reducing subsurface stresses which, if present, increase the likelihood of a wheel failing in the field. In sum, the method of heating the wear area 42 according to the present invention creates a uniform case hardness which results in uniform wheel wear during use and produces uniform compressive stresses to increase the strength and toughness of the wheel.
Preferably, the induction coil 84 is located approximately one-quarter of an inch from the working tread surface 32 during the heating of the wear area 42 . The width of the induction coil 84 is generally ¼-¾ of an inch smaller than the width of the working tread surface 32 . If the wheel 120 has two substantially the same opposing flanges 34 , 36 , the induction coil 84 is typically centered between the flanges. If the wheel has one flange thicker than the other, the induction coil is generally located closer to the thicker flange than the thinner flange. In this way, the right amount of heat can be transferred to the appropriate surfaces of a wheel.
With reference to FIG. 3, the infra-red scanner 76 monitors the temperature of the wear area 42 as the wheel 120 is being heated as shown in FIG. 7 . The eye of the scanner 76 , represented by line 86 in FIG. 3, is preferably aimed at the middle of the working tread surface 32 . This is important because the largest case depth is required in the working tread surface 32 as a result of this surface always being in contact with a rail and subjected to most of the load during operation, which means more metal must undergo transformation for hardening in the tread surface 32 than the flanges 34 , 36 . Thus, measuring the temperature of the working tread surface 32 will help ensure that the heating step continues until the critical temperature is reached in the working tread surface.
The heating of the crane wheel 120 is controlled by temperature rather than by time. Time control would be acceptable if the same type and size of wheel were heated multiple times. However, since the crane industry provides wheels of infinite variability, time control is not the preferred control measure. Temperature control allows for a repeatable process for a highly variable product. The use of an infra-red scanner provides excellent accuracy and repeatability in a temperature controlled process.
With reference to FIG. 8, after the temperature of the working tread surface 32 reaches its critical temperature, the infra-red scanner 76 sends a signal to the induction hardening system 44 or controller 80 to retract the induction coil 84 . It should be noted that the power required by the induction coil 84 to heat the wear area past its critical temperature will vary depending on the size of the wheel being heated. However, the power will typically fall in the range of 150 kilowatts to 450 kilowatts. The controller 80 also informs the retractable device 48 to lower the wheel 120 into the quench bath 55 . Preferably, the wheel 120 is continually rotated about its axis 24 from the beginning of the heating stage and during the quenching stage. The wheel 120 is preferably rotated as it enters the quench bath 55 to assist in providing an agitated quench. As can be appreciated by those skilled in the art, the area of a heated part that first hits a quench will be the first to harden. The agitated quench according to the present invention assists in hardening substantially all of the relevant areas of the crane wheel at the same time thereby creating a more uniform hardened area which results in all of the benefits previously set forth.
With reference to FIG. 4, to further increase the speed of the quenching process and provide even more uniform hardening, the wear area 42 of the crane wheel 120 is sprayed with the quenching agent 55 by nozzles 66 connected to pump 68 . The agitated quench bath 55 and the spraying of the quenching liquid 55 on the wear area 42 optimizes the quenching process by removing the vapor blanket created on the wear area 42 of the wheel 120 during the heating process as quickly as possible to create a more uniform hardened surface. Preferably, the quench tank 54 is directly below the crane wheel 120 as the crane wheel 120 is being heated so that once the part is ready to be quenched, it can be delivered as quickly as possible to the quenching tank 54 . The retractable rotating device 48 ensures a quick transfer from the first heating position to the second quenching position.
As noted, preferably, the quench system is an aggressive system which utilizes directional flows of quenchant 55 supplied by the nozzles 66 submerged in the quench bath 55 . The nozzles 66 provide a high pressure quench 55 to the wear areas 42 of the wheel 120 . This allows for the heat to be quickly drawn away from deep inside the wear area 42 to provide a more uniform hardened surface. A quench bath 55 that does not forcibly apply quench may result in lower case depths and uneven hardening.
After a predetermined time, usually 150 seconds to 400 seconds, depending on the size of the wheel, the wheel 120 is removed from the quench bath 55 . The controller 80 sends a command to device 48 to lift wheel 120 out of the quench bath 55 . Preferably, the wheel 120 will then proceed to undergo a tempering process. With reference to FIG. 9, after the retractable rotating device 48 lifts the crane wheel 120 out of the quench tank 54 , the induction coil 84 is positioned once again near the wear area 42 to heat the wear area 42 of the crane wheel 120 . As during the heating step of FIG. 6, the wheel 120 rotates about its axis 24 . Tempering is preferred because, as can be appreciated by those skilled in the art, it helps prevent the working tread surface 32 and flange surfaces 38 , 40 from cracking. The temper process changes the surfaces from strictly martensite to finely divided ferrite and carbite. This slightly softens the surfaces of the wear area 42 to help reduce wear and pitting. Preferably, the tempering process is performed on the induction system 44 with the same equipment used for the heating process of FIG. 6 . Meaning, the same induction coil 84 and other equipment is used.
The infra-red scanner 76 monitors the temperature of the crane wheel wear area 42 and once a predetermined temper temperature is reached, usually 300-350° F., the scanner 76 sends a signal to the controller 80 to retract the induction coil 84 and informs the retractable device 48 to lower the wheel 120 into the quench tank 54 for cooling, as shown in FIG. 10 . Preferably, the wheel 120 is rotated about its axis 24 during the cooling step and the wheel wear area 42 is sprayed with the quenching liquid 55 . The power required by the induction coil 84 to temper wheel 120 is considerably less than the power to heat wheel 120 to its critical temperature, usually, in the range of 50 kilowatts to 200 kilowatts, depending on the size of the wheel.
To provide a wheel according to the present invention and increase productivity, it is preferred that the wheel be supported by the retractable rotating device 48 during the entire process as shown from the beginning in FIG. 3 through the end of the process as represented by FIG. 10 .
As compared to the prior salt bath process and carburizing process described herein, a typical 500-pound crane wheel is capable of being hardened according to the present invention in considerably less time and with lower temperatures than used by the prior processes. Because the process according to the present invention provides localized heating as described above, a 500-pound wheel is capable of being hardened at about 1500° F. in about 15 minutes.
The method of the present invention is designed to create a crane wheel 120 with a hardened portion as shown in FIG. 13 . The slightly shaded portion shown in FIG. 13 represents a hardened portion 88 of a crane wheel 120 according to the method of the present invention. The hardened portion 88 includes the wear area 42 of the crane wheel 120 and extends beneath the working tread surface 32 and into the outer flanges 34 , 36 such that the outer flanges 34 , 36 are not completely through hardened.
As can be observed in FIG. 13, portions 35 , 37 of the flanges 34 , 36 , respectively, remain ductile or as forged as does the body 28 of wheel 120 . These as forged portions 35 , 37 increase the impact strength of the flanges 34 , 36 of the crane wheel 120 . Moreover, partially hardening the flanges 34 , 36 results in providing compressive stresses in the wheel 120 at the location where the as forged ductile material of the wheel 120 ends and the hardened portion 88 begins. These compressive stresses greatly improve the strength characteristics of the wheel 120 .
As shown in FIG. 13, the hardened portion 88 is of a substantially parabolic shape extending beneath the working tread surface 32 and into portions 35 ′, 37 ′ of each flange 34 , 36 , respectively, such that each flange 34 , 36 is not completely through hardened. As can be observed, the heat treat case depth is greatest at the center of the working tread surface 32 and tapers off towards the wheel flanges 34 , 36 . The required heat treat depth is assured at the inside of the wheel flange 34 , 36 and at the center of the working tread surface 32 , not at and around the outer portions 35 and 37 of flanges 34 , 36 . According to the subject invention, flange through hardening, like that shown in FIGS. 1 and 2, is not acceptable. For those crane wheels that utilize a single flange, a partial parabolic shape would be formed. The hardened portion would extend beneath the working tread surface as shown in FIG. 13 and into the single flange as if only a single flange was shown in FIG. 13 . For those wheels that do not have any flanges, the hardened portion would represent yet a smaller partial parabolic shape, such as a bowl, beneath the working tread surface.
Preferably, approximately two-thirds to approximately three-fourths of each flange 34 , 36 is hardened. The overall hardened portion is preferably hardened to a range of 58-62 Rockwell-C.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention in the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings in skill or knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain the best modes known for practicing the invention and to enable others skilled in the art to utilize the invention as such, or other embodiments and with various modifications required by the particular applications or uses of the present invention. It is intended that the appended claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
Various features of the invention are set forth in the following claims.
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A specialized induction facility provides localized heating in only the desired wear areas of a crane wheel while leaving the supporting material “as-forged” and ductile. The wear area of a crane wheel is hardened such that flanges extending out from a working tread surface are not completely through hardened.
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FIELD OF THE INVENTION
This invention relates generally to a joint construction for a papermakers fabric. More particularly, the invention relates to pintle seamed joints for papermakers wet press felts.
BACKGROUND OF THE INVENTION
In conventional papermaking machines, wet felts convey the sheet of paper, paperboard, etc., from the wire or cylindrical mold thrugh various water removing equipment.
Such wet felts are often woven endless and are applied as such to the rolls of the papermaking machine. The installation of endless wet felts in the past has required cessation of operations for extended periods of time with the resultant loss of production from the paper machine.
Recent developments have resulted in greater use of seamed press felts which are joined or seamed by a pintle to simulate the endless condition. This construction is generally described as a pintle seamed joint. The inability to produce a pintle seamed joint geometry which does not differ substantially from the plane of the fabric body has been a major fault with this newer construction.
In view of the prior failures, the present invention teaches the use of an extended loop in the seam area. Although this is occasionally contrary to the prior art theory of continuing the same weave or float length through the fabric seam area, the invention permits greater control over the seam configuration and, in fact, results in a more uniform fabric geometry at the seam.
U.S. Pat. 2,883,734 provided a wet felt of a woven open-ended strip construction which was made endless by joining together the extensions of yarn from the weave of the felt at the joining ends thereof. One end of the wet felt is fed through the dryer section of the machine, until it completes a full loop. The yarn extensions at the joining ends of the felt are continuous with the weave system thereof and are used for joining together the two ends of the felt, and a textile yarn or cord is used to secure both sets of yarn extensions together and retain the two ends of the felt connected together to form an endless belt structure. Thus, the wet felt is installed without having to disassemble the machine.
The art is replete with descriptions of seam constructions for papermakers felts; see for example the disclosures of U.S. Pat. Nos. 2,883,734; 3,283,388; 3,309,790; 4,123,022; 4,141,388; 4,186,780 and 4,364,421. In general, the seam constructions of the prior art have not been entirely satisfactory for all purposes and applications.
U.S. Pat. No. 4,500,590 issued Feb. 19, 1985 to Smith, attempts to solve this problem via a composite pintle including a polyester core and an outer low-melt polymeric sheath which has been softened and deformed. This composite pintle exhibits a profile which occupies void areas in the mesh of the helical fabric in the area of the pintle joint.
The difficulty in establishing overall uniformity between the caliper of the fabric and the caliper of the seam has been recognized in the prior art. Likewise, it has been recognized, in the prior art, that the normal construction of a single layer fabric results in a fabric thickness which is less than three times the yarn diameters, due to the crimp introduced into the yarns and a seam thickness which is about three yarn diameters. For example, a single layer fabric of normal construction, having monofilament warp threads and weft threads, would typically have a thickness which is only two and a half times the yarn diameter, rather than three times the yarn diameter as may be expected. This condition is discussed in detail in U.S. Pat. No. 4,026,331 which is incorporated herein by reference as if fully set forth. As recognized in U.S. Pat. No. 4,026,331, one approach to controlling equality between seam thickness and fabric thickness is to select certain weaves and cover factors which will permit equalization and uniformity of overall fabric caliper. However, such an approach eliminates many desirable weave constructions and fabrics which do not have the requisite percentage of warp cover or met the weave limitations. Accordingly, the present invention sets forth a structure which will accomplish the goals of U.S. Pat. No. 4,026,331 without the inherit limitations thereof.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a prior art construction.
FIG. 2 is a side elevation taken from the view 2--2 of FIG. 1.
FIG. 3 is a section taken through the line 3--3 of FIG. 2.
FIG. 4 is a plan view of the seam according to the instant invention. The weave repeat of the fabric is the same as that shown in prior art FIG. 1.
FIG. 5 is a side elevation, similar to FIG. 2, of a construction according to the present invention.
FIG. 6 is a section view taken along the line 6--6 of FIG. 5.
FIG. 7 illustrates the construction of FIG. 5 in a closed seam and also includes differential cross hatching to indicate removable yarns.
FIG. 8 illustrates one half of the construction depicted in FIG. 7 with a batt needled to the base fabric.
FIG. 9 illustrates the construction of FIG. 8 after removal of selected stuffer yarns.
FIG. 10 illustrates a construction similar to FIG. 9 after the fabric seam has been closed and for a fabric with batt needled to both sides of the fabric.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The terms machine direction and cross machine direction as used herein refer to the fabric orientation on the papermaking machine rather than in the loom.
FIG. 1 is a portion of a prior art seam construction in a woven fabric which includes a plurality of machine direction yarns 1 interwoven with a plurality of cross machine direction yarns 4. In order to seam the fabric, a plurality of integral contiguous seaming loops 2 are formed at each terminal end of the woven fabric. The seaming loops 2 are formed using techniques known in the art. To place the fabric in service, loops from each end of the fabric are intermeshed to form a channel and a pintle, such as 3, is inserted to retain the fabric ends together in a substantially continuous, endless structure.
With reference to FIGS. 2 and 3, the prior art construction will be explained in more detail. It will be understood by those skilled in the art that yarns 1 and 4 will generally have some crimp and that the loop 2 and pintle 3 will generally not have the same degree of crimp. Thus, the FIGS. are only illustrative of the weave. As shown in FIG. 2 , the machine direction yarn 1 is looped, reversed and passed in a mirror image weave with the end cross machine direction yarn 4. This may be done after weaving of the fabric in a subsequent operation or at the time of weaving if the weaving is preformed on an endless loom. The machine direction yarn 1 forms a crossover 5 and a loop 2. The loop 2 is a continuous arcuate portion of the same machine direction yarn 1. The center to center distance between the last cross machine direction yarn 4 and the pintle 3 in the eye of loop 2 defines the loop length and is designed L. The distance X indicates the overall free length of the loop 2 from the center of the crossover 5. The distance E indicates the portion of the loop length L from crossover 5 to the last cross machine drection yarn 4. The distance c is the length between cross machine direction yarns 4 in the fabric weave repeat.
The above prior art seam construction, which is in accordance with the prior theory, is deficient in that the distance E is equal to about one-half the distances L and X. The free loop length X is substantially equal to the distance C between cross machine direction yarns 4. This results in the loop 2 being formed substantially in the repeat pattern of the weave as was consistent with the prior art thinking. Utilization of this prior art construction renders it almost impossible to achieve the same fabric gauge or caliper G in the body of the fabric and at the loop or seam area. If the pintle 3 is of the same size as the cross machine direction yarn 4, the gauge or caliper at the loop 2 will be larger. If the pintle 3 is reduced in size, in an effort to decrease the loop gauge or caliper, the loop forming machine direction yarn will be under less control and will tend to rotate in the horizontal plane of the fabric due to axial forces in the yarn 1. Thus, all efforts to bring the gauge of the fabric and the seam area into equality require compromises in the form and structure of the loops 2. This relationship is further explained hereinafter.
FIG. 3 is a partial view of the forward section of the machine direction yarn 1 along the line 3--3 of FIG. 2. The plane line F indicates a plane along the longitudinal axis of the section of the yarn forming loop 2. Loop 2 is a continuous arcuate portion of yarn 1 as it is reversed on itself and woven back into the fabric. The plane line R indicates a plane along the longitudinal axis of what would be the opposing yarn forming a loop 2 and shows that it is a mirror image of the opposed yarn. The plane H indicates the horizontal plane of the woven fabric through the center or eye of loop 2 and the fabric. The plane v indicates the vertical plane perpendicular to plane H. The angle between the longitudinal axis F of the loop 2 and the horizontal plane H is identified as β.
The obtuse angle β is directly related to the distances L and X and their relationship to E. As X approaches E, the distance L is decreased. As L decreases the axial forces on the yarn 1 and loop 2 are increased. The increased axial forces tend to rotate the arcuate portion of loop 2 closer to the plane H and thereby increase the angle β.
It has been found that in order to eliminate or substantially reduce axial tension and to have the angle β approach, as closely as possible 90°, the difference between the distances L and X should be decreased and the differences between L and X with respect to E should be increased.
In a preferred embodiment of the invention, FIG. 4, the base fabric weave is the same as that of prior art FIG. 2. The machine direction yarn 11 extends over the end cross machine direction yarn 14, forms an elongated loop 12 and weaves back into the fabric in a mirror image. With reference to FIG. 5, this produces crossover 18 and the loop 12. The loop length L, as shown, is elongated and substantially greater than in the prior art. In this embodiment, it is elongated by at least three times the average diameter of the cross machine direction yarns. In any event, the elongated loop length L is always at least 3 mm. As illustrated, L is about four and a half times the average cross machine direction yarn diameter plus one-half of the pintle and the diameter of the opposing machine direction yarn. Accordingly, an elongated aperture 19 is created between the free end of the loop 12 and the contiguous fixed end thereof at crossover 18. Aperture 19 always has a length Y which is at least three times the average diameter of the cross machine direction yarn 14. As illustrated, a number of stuffers 16 are inserted in the aperture or channel 19 between the pintle 13 and the crossover 12. The remaining space in between the stuffers and the pintle accommodates the corresponding loop from the opposite end of the fabric. The addition of the stuffers 16 aids in physically maintaining the geometry of the loop 12 at almost the 90° position. This relationship will be discussed in more detail hereinafter.
Generally, the more stuffers that can be inserted, the easier it becomes to form the optimum 90° angle. That is, the lengths L and X come closer together and the arcuate portion of the loop 12 will more nearly approximate 90°. Likewise, the distances Y and X approach each other with the difference ideally approaching the diameter of the yarn 11.
FIG. 6 is a partial view of the machine direction yarn 11 along the 1ine 6--6 in FIG. 5 and is comparable to FIG. 3. The angle β indicates the angle from the plane H to the vertical plane v of the machine direction yarn at the crossover 18. To obtain the best results, the angle β should approximate 90°. The longitudinal axis of the arcuate portion of the yarn forming loop 12, as indicated by the plane line F, is brought into coincidence with the vertical plane v. Note also that the portions 20 of the machine direction yarn adjacent to the arcuate portion of the loop 12 extend toward the body of the fabric in a more horizontal orientation than in the prior art and are generally more parallel to the plane H. Thus, it can be seen that the elongated loop has reduced the axial tension and the tendency of the loop forming yarn to rotate into the horizontal plane H of the fabric.
With respect to formation of the loop and the utilization of stuffer 16, it will be appreciated by those skilled in the art that insertion of stuffers 16 will tend to minimize collapsing of the loop and to resist rotation into the horizontal plane.
In general, the desired elongated loop may be formed by placing the machine direction yarns under tension. However, the application of tension to the fabric in the machine direction will often result in crimp interchange and shifting of the cross machine direction yarns. The use of a loop forming mandrel of the desired elongated geometry may be used to form the loop. Alternatively, the stuffers may be utilized to preserve the weave structure and to prevent loop crushing. In addition, utilization of stuffers enables a loop structure having a gauge or caliper which is substantially identical to that of the fabric. As noted previously, utilization of a smaller diameter pintle wire will reduce loop caliper. Although the elongated loop will not have the same rotational tendencies of the prior art loop, the stuffers help to maintain fabric caliper throughout the length of the elongated loop. By selecting stuffers which have an average diameter which is less than that of the cross machine direction yarns, it is possible to compensate for the crimp in the fabric weave and to obtain substantially the same caliper throughout the fabric and seam area. Furthermore, stuffers reduce the amount of tension which is required to preserve the elongated loop and ease in manufacturing of the base fabric. Stuffers present additional advantages which will be discussed in more detail hereinafter.
In FIG. 7, the seam is shown in the completed form without a batt on the base fabric. The prime numbers indicate the identical counterparts of the opposing end of the woven fabric. Still with reference to FIG. 7, it will be noliced that alternate stuffers among the stuffers 16 and 16' are shown with different cross hatching than in the prior figures. The differential cross hatching illustrated a construction in which certain of the stuffer yarns do not form part of the final running felt. Accordingly, selected stuffers are comprised of removable yarns. In the preferred embodiment, the removable stuffers are dissolving yarns, such as Solvron two-ply which is available from Hickory, N.C. In an alternative embodiment of the invention, fusible yarns are used in place of the soluble yarns. Thus, with reference to FIG. 7, the stuffer yarns 16 would be fusible yarns, such as fusible Wonder Thread monofilament nylon which is available from the Shakespeare Company in Columbia, S.C.
At present, soluble yarns are preferred as the removable yarns due to their ability to be removed after installation of the felt on the papermaking equipment. The soluble yarns may be retained in the finished manufactured felt to preserve loop geometry. After the fabric is installed and placed under tension, the yarns are dissolved from the felts. Since it is desirable to have the option of removing the yarns during the manufacturing or at the installation, soluble yarns are preferred.
With the use of fusible or meltable yarns in the alternative embodiment, the felt after the needling of batt 20 thereto is subjected to the yarn manufacturers suggested temperature and pressure in order to melt or remove the fusible yarns 16. As a result of the melting operation, the fusible yarns will be dispersed throughout the felt and voids in the seam structure will be created as is shown in FIGS. 9 and 10.
FIG. 8 shows the seam construction of FIG. 3 with a batt 20 thereon. The batt can be needled into the stuffers 16 in the same manner as with the cross machine direction yarns 4. This enables the batt to be strongly anchored to the seam. In addition, the stuffers provide control over differences in the permeability and density between the seam area and the woven fabric.
FIGS. 9 and 10 illustrate the construction of FIG. 8 with selected stuffers removed. FIG. 9 illustrates batt material 20 on the paper supporting surface only and FIG. 10 illustrates batt material on both surfaces.
To place the woven fabric of the invention in service, it is fitted around the usual cylinders with the terminal ends 17 and 17', of FIG. 7, juxtapositioned. The end loops 12 and 12' are then intermeshed to form the pintle channel 15. The free ends of respective loops abut the stuffers of the opposite end. A pintle 13 is passed through the pintle channel 15 to interconnect the fabric ends. Although an optimum 90° anqle at the loops 12 and 12' maximizes the advantages of the invention, it is very difficult to obtain such complete control of the yarns. In practice, loops 12 and 12' which form a substantially vertical plane perpendicular to the horizontal plane of the fabric at about 90°±15° will provide the benefits of the invention.
With respect to actual construction of the fabric and the seaming loops, it is recognized that the fabric may be flat woven and the seaming loops formed through known loop forming techniques or back weaving or that the fabric be woven endless or circular with the loops be formed in the loom as part of the weaving process. These weaving techniques will be known to those skilled in the art. In the known techniques, a looping wire or similar device may be used to form the actual loop and to simulate the pintle location during weaving. In the present invention, the stuffers may be placed within the loop aperture during or after weaving in a known manner of applying stuffers to the woven fabric. If inserted during weaving, the stuffers are merely laid in the weave as it progresses on the loom without interweaving.
With reference again to FIG. 8, it will be appreciated that the batt 20 can be applied to the woven fabric through needling or the application of adhesives. When needling is utilized it will generally stabilize the location of the stuffers through intermingling of fibers. When adhesives are utilized which do not penetrate to the level of the stuffers, it is preferred to fix the stuffer by other means. For example, the stuffers may be retained relative to each other and the fabric by an adhesive. Likewise, the stuffers may be retained by application of a suitable material at the selvages of the fabric. Generally, papermakers fabric are subjected to heat setting and further processing which assist in stabilizing the fabric. The actual stabilizing method is subject to design considerations as will be known to those skilled in the art.
With respect to the yarns employed in the present invention, it is preferred to utilize continuous monofilament yarns. However, it is recognized that multi-filament yarns and cotton count yarns may be utilized. With respect to the stuffer yarns, it will be recognized that the stuffers may be of the same material as the remainder of the fabric or may be selected for certain characteristics. Those skilled in the art will recognize that stuffer yarns are often spun yarns or cotton count yarns which are selected to achieve certain characteristics of permeability and density in the seam area.
With respect to the yarn geometry, the present description has referred to circular yarns which may be generally described by their diameter or axis, see FIG. 3. However, shaped yarns may be utilized in the present invention.
With respect to the pintle, it will be understood by those skilled in the art that one or more pintles may be used and that the pintles are not required to bear a one to one relationship with the cross machine direction yarns.
Those skilled in the art will appreciate that the many modifications to the above described preferred embodiments may be made without departing from the spirit and scope of the invention.
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An improved loop construction for use in closing the ends of an open papermaker's fabric is disclosed. The loop constuction, as disclosed, is elongated to achieve a minimum loop length of at least three millimeters. The loop is formed by an arcuate portion which defines the free end of the loop and adjacent portions which are interwoven with the fabric body in a repeated pattern. As a result of the disclosed construction, the continuous arcuate portion of the seaming loop is positioned vertically with respect to a plane through the horizontal plane of the fabric. The continuous arcuate portion of the loop is within 15° of the perpendicular to the horizontal plane of the fabric.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to U.S. Provisional Patent Application Ser. No. 60/465,617 filed Apr. 24, 2003.
BACKGROUND OF INVENTION
[0002] The current state of the art for controlling the temperature for an engine, e.g., an internal combustion engine, is by using a mechanical wax pellet thermostat to control the flow of coolant to the radiator for a vehicle. This thermostat is a poppet-type of valve that is either fully closed at room temperature or fully open when an engine temperature reaches a predetermined set point.
[0003] There are a number of problems associated with the typical mechanical wax pellet thermostat. Since the temperature-sensing element i.e., wax pellet, must be positioned in the flow stream, there is a very high-pressure drop with associated losses. For engine systems that have relatively large water pumps to provide the necessary coolant flow rates and associated cooling, significant power from the engine must be utilized. This diversion of power affects the performance of the vehicle and wastes fuel.
[0004] Moreover, the fixed-point temperature setting for the engine is primarily determined by the physical composition of the temperature sensing element, i.e., wax pellet. The softening point of any particular wax pellet is fixed and cannot be changed. Therefore, the thermostat is absolutely static with the thermostat either blocking fluid flow or providing maximum fluid flow depending on whether the set temperature is achieved. There is absolutely no dynamic control of engine temperature with a conventional thermostat.
[0005] The present invention is directed to overcoming one or more of the problems set forth above.
SUMMARY OF INVENTION
[0006] In one aspect of this invention, a valve for regulating fluid flow is disclosed. This valve includes a stepper motor, a first valve portion that includes an inlet port for receiving fluid into the valve, a second valve portion that includes an outlet port for dispensing fluid from the valve, a third valve portion located between the first valve portion and the second valve portion, a first member that is rotatable and operatively attached to the stepper motor, and a second member, having a first portion and a second portion, that is engageable with the first member for linear movement of the second member between a first position and a second position when the first member is rotated by the stepper motor, wherein the first member and the second member are located within the third valve portion and the first portion of the second member located in the first position can block fluid flow between the first valve portion and the third valve portion and the second portion of the second member located in the second position can allow fluid flow between the first valve portion and the third valve portion.
[0007] In another aspect of this invention, a method for regulating fluid flow with a valve is disclosed. The method includes rotating a first member that is operatively attached to a stepper motor within a valve that includes a first valve portion having an inlet port for receiving fluid into the valve, a second valve portion having an outlet port for dispensing fluid from the valve and a third valve portion located between the first valve portion and the second valve portion, and moving a second member, having a first portion and a second portion, from a first position to a second position through interengagement with the rotating first member, wherein the first portion of the second member located in the first position can block fluid flow between the first valve portion and the third valve portion and the second portion of the second member located in the second position can allow fluid flow between the first valve portion and the third valve portion.
[0008] These are merely some of the innumerable aspects of the present invention and should not be deemed an allinclusive listing of the innumerable aspects associated with the present invention. These and other aspects will become apparent to those skilled in the art in light of the following disclosure and accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0009] For a better understanding of the present invention, reference may be made to the accompanying drawings in which:
[0010] [0010]FIG. 1 is a top view a stepper motor driven valve in accordance with the present invention;
[0011] [0011]FIG. 2 is a sectional view of the stepper motor driven valve, taken along Line A-A as shown in FIG. 1, in accordance with the present invention in an open position;
[0012] [0012]FIG. 3 is a sectional view of the stepper motor driven valve, taken along Line A-A as shown in FIG. 1, in accordance with the present invention in a closed position;
[0013] [0013]FIG. 4 is a perspective view of the stepper motor driven valve in accordance with the present invention;
[0014] [0014]FIG. 5 is a sectional view of the stepper motor driven valve, taken along Line B-B in FIG. 3, in accordance with the present invention;
[0015] [0015]FIG. 6 is an exploded view of the stepper motor driven valve in accordance with the present invention;
[0016] [0016]FIG. 7 is a basic schematic of a fluid, e.g., coolant, system for a vehicle that illustrates an engine, a radiator, a pump, and a bypass loop where fluid, e.g., coolant, flow through the bypass loop is controlled by the valve of the present invention; and
[0017] [0017]FIG. 8 is a basic schematic of a fluid, e.g., coolant, system for a vehicle that illustrates an engine, a radiator, a pump, a thermostat and a bypass loop where fluid, e.g., coolant, flow through the bypass loop is controlled by the valve of the present invention.
DETAILED DESCRIPTION
[0018] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as to obscure the present invention. For example, the invention can be applied to virtually any type of device that can benefit from controlled fluid flow. Moreover, this invention can be applied to virtually any type of application that utilizes fluid as a coolant for reducing heat. Although the preferred application involves the thermal management of an engine, e.g., an internal combustion engine, a wide variety of applications that can benefit from thermal management brought about by fluid flow, throughout a range, will be applicable and not necessarily those applications related to motorized vehicles. The fluid is preferably coolant; however, a wide range of fluids may suffice.
[0019] Referring now to the drawings, and initially to FIGS. 1, 2, 3 and 6 , where a valve that is utilized to control fluid, e.g., coolant, flow to provide thermal management is generally indicated by numeral 2 . The valve 2 is shown in a default or unpowered position in FIG. 2. There is a biasing mechanism 4 , which is preferably, but not necessarily, in the form of a return spring. The biasing mechanism 4 applies a load to a plunger 6 . This plunger 6 is preferably aligned with a vertical axis or centerline 3 for the valve 2 in the illustrative, but nonlimiting, embodiment. However, this is not a necessity.
[0020] The plunger 6 preferably includes a first portion 9 and a second portion 11 . The first portion 9 can include a wide variety of geometric shapes and configurations. Preferably, but not necessarily, the first portion 9 is cylindrical or at the very least a portion of the lower portion 9 is cylindrical. Preferably, there is at least one protrusion on the outer circumference of the lower portion 9 and optimally, there is first, upper protrusion 66 , a second, middle protrusion 67 and a third, lower protrusion 68 . Preferably, the plunger 6 , having a longitudinal axis, includes at least one fluid passage 135 , e.g., four (4) fluid passages, that is preferably parallel to the longitudinal axis of the plunger as shown in FIG. 5.
[0021] The second portion 11 of the plunger 6 preferably, but not necessarily, includes a series of triangular support portions 71 , 72 , 73 and 74 , as best shown in FIG. 5. The triangular support portions 71 , 72 , 73 and 74 , each preferably include a slot 77 , 78 , 79 and 80 , respectively, that supports the bottom portion of the biasing mechanism, e.g., return spring 4 .
[0022] As shown in FIGS. 2 and 3, there are a plurality of female threads or a plurality of female indentations 8 (collectively can be referenced as “indentations”) that are integrally formed and located therein that are capable of mating with a plurality of male protrusions or a plurality of male threads 10 (collectively can be referenced as “protrusions”) in a screw 12 . Due to the force of the biasing mechanism, e.g., return spring 4 , there are both translational and rotational loads applied to the plunger 6 .
[0023] Therefore, when the screw 12 rotates, the plurality of male protrusions or threads 10 engage the plurality of the female threads or indentations 8 in the plunger 6 so that the plunger 6 can move up or down along the vertical axis or centerline 3 depending on the direction of rotation of the screw 12 . The screw 12 is operatively connected to a stepper motor 16 . Preferably, the screw 12 is mechanically connected with hardware to the stepper motor 16 ; however, attachment by adhesives, thermal bonding and other methods will suffice. The preferred hardware is a connecting sleeve portion 18 , which is preferably, but not necessarily, part of the screw 12 , which connects to the rotor 20 for the stepper motor 16 , as shown in FIGS. 2, 3 and 6 . An illustrative, but nonlimiting, example of a stepper motor 16 includes SKC Motor Number XE-2002-0962-00 manufactured by Shinano Kenshi Corp., having a place of business at 5737 Mesmer Avenue, Culver City, Calif. 90230. However, a wide variety of stepper motors 16 will suffice for the present invention.
[0024] A wide variety of materials can be utilized for the main components of the valve 2 with the exception of the stepper motor 16 and fluid sealing mechanisms. One illustrative, but nonlimiting, example includes 1503-2 grade of resin that includes nylon 6/6 that is glass reinforced and manufactured by TICONA®, having a place of business at 90 Morris Avenue, Summit, N.J. 07901. However, a wide variety of other materials will suffice for this application. One illustrative, but nonlimiting, example of material for the plunger 6 includes an acetal copolymer. An acetal copolymer is a polyoxymethylene (POM) with a high crystallinity delivering high strength, stiffness, toughness, and lubricity over a broad range of temperatures and chemical environments. An acetal copolymer can be processed by many conventional means including injection molding, blow molding, extrusion and rotational casting. One illustrative, but nonlimiting, example of material for the screw 12 includes nylon 6 combined with polytetrafluoroethylene (PTFE) to reduce friction.
[0025] A feature of this valve 2 is the force balance between the stepper motor 16 and the biasing mechanism, e.g., return spring 4 . This valve 2 is designed so that when an appropriate signal is provided to the stepper motor 16 , there is sufficient force to turn the screw 12 that moves the plunger 6 to compress the biasing mechanism, e.g., return spring 4 , and close the valve 2 . The construction and design of the biasing mechanism, e.g., return spring 4 , can vary greatly to comport with the wide variety of stepper motors utilized to create to balance the force. Conversely, there must be enough force in the biasing mechanism, e.g., return spring 4 , to turn the screw 12 to move the plunger 6 that rotates the stepper motor 16 when power is removed from the stepper motor 16 so that the valve 2 can be opened. Therefore, a feature of this invention is the ability for the valve 2 to go to a full open position as a failsafe when power is removed from the stepper motor 16 .
[0026] As shown in FIGS. 1-4 and as best shown in FIG. 6, the stepper motor 16 includes a protective outer housing end cap 26 that covers the outer top portion of the stepper motor 16 . As shown in FIG. 6, there is a gasket 27 having an electrical terminal connector 28 to provide electrical connections to the terminals (not shown) on the stepper motor 16 . This electrical terminal connector 28 provides a simple electrical interface that can be easily connected to other components in an electrical system.
[0027] As shown in FIGS. 2, 3, 5 and 6 , located below the stepper motor 16 is a valve body 32 . There is a cover member 30 that preferably, but not necessarily, includes a support portion and preferably an upper motor support portion 83 and a lower portion 84 . Preferably, but not necessarily, both an upper motor support portion 83 and a lower portion 84 are cylindrical depending on the geometric shape of the stepper motor 16 . Extending outward from between the upper motor support portion 83 and the lower portion 84 is at least one sealing portion that preferably includes a first outer member 85 and a second outer member 86 . The first outer member 85 and the second outer member 86 operate to seal the cover member 30 to the valve body 32 , as shown in FIGS. 1, 4, 5 and 6 .
[0028] The upper motor support portion 83 , the lower portion 84 , the first outer member 85 and the second outer member 86 may all be part of an integral cover member 30 or each may be separate parts connected together and any combination thereof. Preferably, the cover member 30 is mechanically connected with hardware to the valve body 32 ; however, attachment by adhesives, thermal bonding and other methods will suffice. Preferably, a first bolt 63 and a second bolt 64 are utilized to secure the first outer member 85 and the second outer member 86 , respectively to the valve body 32 .
[0029] As shown in FIGS. 2, 3 and 5 , the lower portion 84 includes an outer flange 117 and at least one protruding member 119 located within the outer flange 117 . There is preferably a pair of retaining guide members 121 and 123 located on the second portion 11 of the plunger 6 , as shown in FIG. 5. This provides an anti-rotational feature so that the plunger 6 only translates force along the centerline 3 of the valve 2 .
[0030] Preferably, but not necessarily, located near a bottom portion of the outer surface of the outer flange 117 is at least one protrusion 92 that forms at least one u-shaped channel 94 , which is followed by an extending lip portion 96 , as shown in FIG. 6.
[0031] There is a radial seal 42 located on the inside of the valve body 32 . The radial seal 42 may include a wide variety of geometric shapes and configurations; however, the preferred embodiment includes at least one rectangular portion 102 and at least one c-shaped portion 104 . The rectangular portion 102 is preferably located within the u-shaped channel 94 in the outer flange 117 and the c-shaped portion 104 is preferably positioned adjacent to the extending lip portion 96 . A seal made of polytetrafluoroethylene (PTFE) or a lip seal may also be utilized. The radial seal 42 keeps the load low that is due to the differential pressure.
[0032] There is a first o-ring 38 located between the cover member 30 and the connecting sleeve portion 18 of the screw 12 and the stepper motor 16 . There is also a second o-ring 40 located between the biasing member, e.g., return spring 4 , and the plunger 6 . An illustrative, but nonlimiting material can include a Nitrile/Buna-N type of material as well as EPDM at higher temperatures. An illustrative, but nonlimiting, manufacturer can include Quality Synthetic Rubber, Inc. (QSR), having a place of business at 1700 Highland Road, Twinsburg, Ohio 44087.
[0033] The valve body 32 includes an inlet port 46 for receiving fluid and an outlet port 48 for releasing fluid. There is a third valve portion 50 where the plunger 6 moves up and down that is located between a first valve portion 54 and a second valve portion 56 .
[0034] The first valve portion 54 receives fluid, e.g., coolant, into the valve 2 and includes the inlet port 46 . The second valve portion 56 transmits fluid, e.g., coolant, from the valve 2 and includes the outlet port 48 .
[0035] As shown in FIG. 3, when the valve 2 is closed, the plunger 6 is positioned as close to the stepper motor 16 as possible in a first position and the plunger completely blocks the flow of fluid, e.g., coolant, in the third valve portion 50 so that the fluid, e.g., coolant, flowing into the inlet port 46 , through the first valve portion 54 is blocked by the first portion 9 of the plunger 6 so that fluid, e.g., coolant, cannot go into the second valve portion 56 that is in fluid communication with the outlet port 48 and the fluid, e.g., coolant, does not have any access to the fluid passage 135 .
[0036] As shown in FIG. 2, when the valve 2 is open, the plunger 6 is positioned on the bottom of the valve body 32 in a second position and as far away from the stepper motor 16 as possible. This allows fluid, e.g., coolant, to flow between the inlet port 46 , through the first valve portion 54 , and then into the third valve portion 50 through the fluid passage 135 in the plunger 6 . Fluid, e.g., coolant, then flows out through the second valve portion 56 and then the outlet port 48 . Therefore, the present invention includes a first position where the valve is fully closed and a second position where the valve is fully open. However, it is only this specific illustrative embodiment where the position of the plunger 6 to the stepper motor 16 has any relevance to these two positions and with slight modifications to the valve 2 the relationship of the position of the plunger 6 to the stepper motor 16 and these two positions can be reversed.
[0037] Due to the radial seal 42 , any high pressure differential pressure across the valve 2 between the first valve portion 54 and the second valve portion 56 has a negligible effect on the pressure balance on the plunger 6 caused by the stepper motor 16 and the biasing mechanism, return spring 4 . Therefore, the pressure drop across the valve 2 is relatively low due to the radial seal 42 .
[0038] Under normal operating conditions, the stepper motor 16 will be powered to rotate the screw 12 in either a clockwise or counterclockwise direction to move the plunger 6 either up or down. There are two operating conditions. The first condition is the full opening region. The full opening region is from when the plunger 6 is as far as possible to the stepper motor 16 to being extended to the point where the plunger 6 is in contact with the bottom of the valve body 32 to allow full fluid flow. The second operating condition is when the valve is in a fully closed position. This is when the plunger 6 is as close as possible to the stepper motor 16 and the plunger 6 is in contact with the radial seal 42 . Between the first operating condition and the second operating condition, the valve 2 controls the fluid flow in a step-wise linear manner, which can be dynamically altered based on operating conditions to provide a fully variable fluid flow.
[0039] The degrees of rotation for the stepper motor 16 can range from about zero (0) degrees per step to about one hundred and eighty (180) degrees per step and preferably from about twenty (20) degrees per step to about fifty (50) degrees per step and optimally about 1.8 degrees per step. The pitch of the screw 12 can range from about two (2) male protrusions or threads 10 per inch to about fifty (50) male protrusions or threads 10 per inch and preferably from about three (3) male protrusions or threads 10 per inch to about eight (8) male protrusions or threads 10 per inch and optimally about five (5) male protrusions or threads 10 per inch. Therefore, the plunger 6 can travel from about 10 inches per step to about 0.000001 inches per step and preferably from about 0.01 inches per step to about 0.001 inches per step and optimally about 0.001 inches per step. As an illustrative example, at 1.8 degrees per step with the pitch of the screw 12 at five (5) male protrusions or threads 10 per inch and the plunger 6 traveling 0.001 inches per step, results in 500 steps for the plunger 6 to travel one (0.5) inch for very precise flow control.
[0040] Referring now to FIG. 7, as one illustrative, but nonlimiting application, the valve 2 can be utilized to provide fluid, e.g., coolant, flow from an engine 127 through a first fluid conduit 137 and into either the valve 2 or a bypass loop 133 . The valve 2 controls the flow of fluid, e.g., coolant, into a radiator 131 via a third fluid conduit 139 . The fluid, e.g., coolant, then goes into a fluid pump 129 from the radiator 131 via a fourth fluid conduit 141 and the bypass loop 133 and then back into the engine 127 via a second fluid conduit 143 . By diverting more fluid, e.g., coolant, into the bypass loop 133 rather than the radiator 131 , the engine 127 can run hotter with greater fuel efficiency and reduced emissions. The valve 2 can be operated from sensor data from a processor (not shown) to maximize performance of the engine 127 . Preferably look-up tables can be utilized in conjunction with the sensor data. This will control the temperature of the engine 127 through a complete range of fluid flow rather than a thermostat being merely off or turned on. The previously mentioned failsafe feature of the valve 2 is important so that fluid, e.g., coolant, can always be provided to the radiator 131 to prevent damage to the engine 127 .
[0041] Referring now to FIG. 8, as another illustrative, but non-limting application, the valve 2 can be utilized to control fluid, e.g., coolant, flow through the bypass loop 133 from the engine 127 from a first fluid conduit 137 . The standard thermostat 125 has not reached the set point, all flow of fluid, e.g., coolant, from the fluid pump 129 through a second fluid conduit 143 and into the engine 127 and then into the bypass loop 133 via the first fluid conduit 137 and then back into the fluid pump 129 . By controlling the amount of fluid flow in the bypass loop 133 , the engine 127 can run hotter with greater fuel efficiency and reduced emissions. The valve 2 can be operated from sensor data from a processor (not shown) to maximize performance of the engine 127 . Preferably, look-up tables can be utilized in conjunction with the sensor data. This will control the temperature of the engine 127 through a complete range of fluid flow until the set point of the thermostat 125 is reached. At this point, the valve 2 can be operated in conjunction with the thermostat 125 to accurately control the temperature of the engine 127 with fluid going through the thermostat 125 via the first fluid conduit 137 and into a radiator 131 via a third fluid conduit 139 . From the radiator 131 fluid goes back into the inlet for the fluid pump 129 via a fourth conduit 141 .
[0042] Although the preferred embodiment of the present invention and the method of using the same has been described in the foregoing specification with considerable details, it is to be understood that modifications may be made to the invention which do not exceed the scope of the appended claims and modified forms of the present invention done by others skilled in the art to which the invention pertains will be considered infringements of this invention when those modified forms fall within the claimed scope of this invention.
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A valve for regulating fluid flow and associated method of use. The valve includes a stepper motor, a first valve portion having an inlet port for receiving fluid into the valve, a second valve portion having an outlet port for dispensing fluid from the valve, a third valve portion located between the first valve portion and the second valve portion, a first member that is rotatable and operatively attached to the stepper motor, and a second member, having a first portion and a second portion, which engages the first member for linear movement of the second member between a first position and a second position when the first member is rotated by the stepper motor to block fluid flow when the second member is located in the first position and allow fluid flow when the second member is located in the second position.
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PRIORITY DATA
[0001] This application is a division application based on U.S. patent application Ser. No. 10/951,341 filed on Sep. 27, 2004 and which claims priority to U.S. Provisional Patent Application Ser. No. 60/506,630 filed Sep. 26, 2003.
FIELD OF THE INVENTION
[0002] This invention relates to the field of automatic stapling devices, specifically devices which form staples and immediately insert the staple into the workpiece or material to be secured together. The present invention provides for a stapler housing which provides operating assemblies on key tracks within the housing and which provides for continued support of the staple during the insertion step as well as automatic adjustability and automatic centering of a selected staple wire length on the staple forming jig during the stapling process
DESCRIPTION OF THE RELATED ART
[0003] In order to staple material such as paper, cardboard or the like, use is made, according to the prior art (DE 44 44 220), in stapling machines of so-called stapling heads which, in addition to other components, have staple-forming apparatuses. In these stapling apparatuses, which are also referred to as staple forming means, a cut-to-length piece of wire is bent into a u-shaped staple before being driven, by means of a staple driver, into the paper stack which is to be stapled.
[0004] The staple driver in this case is usually fitted in a moveable manner on a pusher in a forming-means housing. In order to form the staple, the forming-means housing has two side guides, in each of which is provided a groove for guiding the wire. The two end legs of the staple are formed in said side guides. The pusher itself comprises a driver which is positioned thereon and has an accommodating groove in a direction transverse to the movement direction so that the crosspiece of the staple or crown is formed between the two end legs. The entire forming means is actuated via a drive acting on the pusher.
DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 a is an exploded view of the device which is shown assembled in FIG. 3 d;
[0006] FIG. 1 b is an exploded front and left side perspective view of the bender rail shown assembled in FIG. 1 a;
[0007] FIG. 1 c is a front elevation view of a staple showing the parts of a typical staple;
[0008] FIG. 1 d is a front and left side elevation assembled view of the staple device of FIG. 1 a;
[0009] FIG. 1 e is an exploded rear and left side perspective view of the bender rail shown assembled in FIG. 1 a;
[0010] FIG. 2 is an exploded view of the body of the staple device which is shown assembled in FIG. 1 a;
[0011] FIG. 3 a is a left side elevation view of the staple forming and insertion device having the cutter box adjustment unit attached thereto and the cutter box 20 shown rotated downwardly in the maintenance position;
[0012] FIG. 3 b is a left side elevation view of the assembled staple forming and insertion device with the cutter box adjustment unit 22 shown in cross-section view taken along line A-A of FIG. 3 c with the cutter box adjustment unit in the engaged position and showing the spline gear 24 of the adjustment unit registered with the adjustment wheel 26 of the cutter box 20 ;
[0013] FIG. 3 c is a top perspective view of a gang of three stapling forming and insertion devices 10 engaged with a single cutter box adjustment unit 22 and showing the top surface of the cutter box adjustment unit in fragmentary view to reveal the spline gear 24 seated within;
[0014] FIG. 3 d is a front elevation view of FIG. 3 c with the case of the cutter box adjustment unit removed to show the positioning of spline gear 24 against adjustment wheel 26 of cutter box 20 ;
[0015] FIG. 4 a is an enlarged view of Area A of FIG. 4 b and showing the pinch-cut knives in closed position;
[0016] FIG. 4 b is a side elevation view of the operating components of the staple forming an insertion device with the cutter box 20 ( FIG. 1 d ) and the body 12 of the staple device removed for clarity;
[0017] FIG. 4 c is an enlarged portion of area B of FIG. 4 d showing the pinch cut knives in open position;
[0018] FIG. 4 d is a side elevation view similar to that of FIG. 4 b of the operating components of the staple forming an insertion device with the cutter box 20 ( FIG. 1 d ) and the body 12 removed for clarity and showing the drive rail 16 in the downward position to drive a formed staple into a workpiece and the shoe 56 drawn rearward to allow the staple to supportably slide down the face of shoe 56 as the staple is driven into the workpiece and the former tool moved forward;
[0019] FIG. 5 is an exploded view of the former tool which is used to hold, orient and align the wire for forming into a staple by the bender rail;
[0020] FIG. 6 is a cross-section view taken along line B-B of FIG. 1 a of the shoe and tongue which is used to support the crown of the staple as it travels down wire guide groove 30 as staple insertion takes place;
[0021] FIG. 7 is a rear and left side exploded view taken along line J-J of FIG. 8 of a portion of the wire capture mechanism or the wire advancing drive of FIG. 8 and showing the movable off-on pins 86 with three of the pins in the raised “off” position 86 a which prevents frictional capture of the wire in the wire advancement drums;
[0022] FIG. 8 shows the wire advancing drive or wire feed mechanism which receives multiple continuous strands of wire from bulk wire spools to allow for selection of specific wire lengths to be advanced by a stepper motor 84 ( FIG. 9 ) into the staple forming and insertion device 10 of FIGS. 1-3 d and showing the wire capture mechanism of FIG. 7 in position for coupling to the drive mechanism;
[0023] FIG. 9 shows the wire advancing drive in exploded view;
[0024] FIG. 10 is an exploded view of the wire inlet guide which delivers a continuous length of wire to wire advancing drive shown in FIG. 8 ;
[0025] FIG. 11 shows the incoming wire alignment tubes and wire cleaning pads disposed therebelow for cleaning of the incoming strand of wire; and
[0026] FIG. 12 shows the wire alignment device for guiding the wire as it exits from the wire advancing drive of FIG. 8 and which is spring mounted and distendable from the lower guide plate of wire advancing drive to permit ease of initial threading of new wire through the wire advancing drive.
SUMMARY OF THE INVENTION
[0027] The invention is comprised of two major components which work in tandem to form and insert a staple into material to be stapled together. The first component is the staple forming and insertion device 10 , and the second component is the wire advancing unit.
[0028] The staple forming and insertion unit is shown in FIGS. 3A-C where it is connected to cutter box adjustment unit 22 which permits lateral movement and adjustment of a cutter box 20 of a staple forming and insertion device to accomplish centering of a cut length of staple wire within the staple forming portion of the staple forming and insertion device 10 .
[0029] It will be appreciated that the present invention allows automatic adjustment of the position of the wire within the staple forming and insertion unit to permit the selection and use of a new staple leg length to accommodate a new thickness of material to be stapled. This is accomplished while avoiding manual adjustment of cutter box 20 to center the newly selected staple wire length within the staple forming portion of the staple forming and insertion unit. The present invention also provides for pinch-cutting of the staple wire rather than shear-cutting of the staple wire thereby providing a staple having a chisel point in contrast to the flat or blunt end provided by the shear cutting of the wire in prior art in automatic staple forming units.
[0030] In addition to automatically adjusting for a new overall wire length and centering the newly selected wire length within the staple forming portion of the device to provide generally equal legs to the new staple length, the present invention allows for full automation of the spacing apart of the staple forming and insertion unit heads in conjunction with the automatic selection of a new staple length and the automatic centering of the newly selected length of staple wire with respect to the staple forming and insertion unit. The prior art units merely permitted automatic repositioning of the spacing between staple forming and insertion heads through the use of shaft encoder technology followed by manual adjustment of the cutter box to center the newly selected wire length on the forming apparatus to provide even length staple legs.
[0031] The present invention further allows the bender rail of the forming device to “float” or to move outwardly from the body of the device through the use of spring washers or a “bellville washer” to thereby reduce the pressure on the knives if the knife stroke is not properly adjusted thereby reducing wear on the knives and need for replacement of the knives.
[0032] A Belleville washer is also known as a cupped spring washer, and is a type of non-flat washer having a slight conical shape which gives the washer a spring characteristic. A similar device is a wave washer. Belleville washers are typically used as springs or to apply a pre-load or flexible quality to a bolted joint. Multiple Belleville washers may be stacked to modify the spring constant or amount of deflection. Stacking in the same direction will add the spring constant in parallel, creating a stiffer joint (with the same deflection). Stacking in an alternating direction is the same as adding springs in series, resulting in a lower spring constant and greater deflection. Mixing and matching directions allow a specific spring constant and deflection capacity to be designed.
[0033] The present invention further provides for a beneficial reduction of the number of movable parts which ride on the frame or body of the device by utilizing keys or rails 40 mounted on the body for support of moving parts of the staple forming an insertion unit thereby reducing the repair costs of the device by avoiding wear on the body of the device and allowing for substitution of the mounting rails or keys 40 or the part moving on the support rails or keys rather than replacement of the entire staple forming and insertion unit.
[0034] The present invention further provides for a knife support shoulder which prevents the opposed knife edges from being pushed past one another as a result of misadjustment of the knife stroke and which operates in combination with the “floating” aspect of the bender rail to reduce wear and damage to the cutter knives.
[0035] The invention further comprises a staple forming and cutter head device having a shoe or shoe tongue comprising a radius surface thereon which allows support of the crown of the staple during the insertion of the staple into the work piece thereby permitting a reduction in the gauge of wire that is selected for use in stapling the work piece thereby resulting in a substantial cost savings through use of the present invention.
[0036] The present invention further comprises a stop on the shoe or shoe tongue which avoids overextending of the shoe tongue in its rearward movement thus contributing to breakage of the spring biasing of the shoe tongue in the prior art devices. In one embodiment of the present invention, the stop attached to the shoe or shoe tongue impacts the bender rail of the present invention and prevents overextention rearwardly of the shoe tongue.
[0037] The present invention further comprises the use of a wedge mounting plate for the cutter box which alleviates binding of the cutter box on the mounting plate during the downward stroke of the cutter knives thereby permitting repositioning of the cutter box during operation of the stitching head or staple forming and insertion unit to permit automatic adjustment of the cutter box during the process of selection of a new staple leg length and the centering of the new wire length with respect to the staple forming apparatus.
Wire Selection and Advancing Unit
[0038] The present invention also comprises a wire advancing and length selection drive which permits selection of new wire lengths for feeding to a stitching head or staple forming and insertion unit. The new design is compact and allows for air cooling of the device by air vents or vanes which utilize the rotating motion of the wire advancing drive and stapling unit to direct air toward the stepper motor to cool the motor and adjacent circuit board during its operation to advance the wire through the device.
[0039] The wire advancing drive device comprises, generally, a central driving shaft operated by the stepper motor upon which gears associated with grooved wire advancing drums or cylinders are mounted. The drums are compressible against an opposed set of wire advancing drums to provide frictional capture of the wire therebetween thus providing secure and accurate advancement of the wire in indexed or incremental fashion.
[0040] The invention further comprises individual engagement and stop keys which govern the compression of the drums or cylinders against one another to initiate or terminate wire advancement on an individual wire strand to thereby permit refeeding of a single wire strand through the wire advancing device. The compact design of the inventive wire advancement device permits mounting of the wire advancement device directly adjacent to the stitching head or staple forming and insertion unit. The wire advancing unit further comprises a wire exit alignment unit which is spring biased in position and permits movement of the guide away from the body of the wire advancement unit for ease of insertion of new wire through the device. The wire advancing drive further comprises beveled wire guide plates adjacent to the drums or wheels which compressively capture the wire therebetween thereby permitting self feeding of a new wire strand through the wire advancing drive.
DETAILED DESCRIPTION
[0041] First referring to FIGS. 3 c and 3 d, three staple forming and insertion devices 10 are shown gang mounted as would be the case on a gathering and stapling unit of a printing operation. Devices 10 are engaged with cutter box adjustment unit 22 which, in the present invention, operates to properly space cutter box 20 ( FIG. 3 b ) of device 10 to permit proper positioning of a length of wire within cutter box 20 device 10 to allow formation of equal leg lengths 101 of a typical staple 100 ( FIG. 1 c ).
[0042] The adjustment of cutter box 20 by cutter box adjustment unit 22 functions in the following manner: Cutter box adjustment unit 22 contains a spline gear 24 which engages with or registers with cutter box adjustment wheel 26 of cutter box 20 . Cutter box adjustment wheel 26 is provided with a central threaded void 28 b ( FIG. 1 a ) for mounting of the wheel 26 on threaded post 28 ( FIG. 1 a ). Adjustment of the position of cutter box 20 along the length of cutter box threaded post 28 in the directions of arrows D ( FIG. 3 d ) is accomplished by the rotation of cutter box adjustment wheel 26 which is urged into rotation by spline gear 24 of cutter box adjustment unit 22 .
[0043] In this manner, when it is desired to change the length of the legs 101 of a staple 100 ( FIG. 1 c ), a longer or shorter length of wire is released from the wire supply feeding cutter box 20 and a control unit signals cutter box adjustment unit 22 to rotate in the proper direction indicated by Arrow D ( FIG. 3 d ) to adjust the position of cutter box 20 on cutter box threaded post 28 . The movement of cutter box 20 on cutter box threaded post 28 shifts cutter box 20 in the directions indicated by Arrow D ( FIG. 3 d ) to position cutter box 20 nearer to, or farther from, staple forming jig 29 ( FIG. 1 a ) of bender rail 18 thereby allowing centering the length of wire that is cut by cutter box 20 with respect to staple forming jig 29 and wire guide grooves 30 ( FIG. 1 a ) of staple forming jig 29 . The result of this automatic movement caused by signals to cutter box adjustment unit 22 is to provide two generally equal length legs 101 on staple 100 ( FIG. 1 c ). It will be appreciated by those skilled in the art that the signals to cutter box adjustment unit 22 are to be supplied from a controller that is provided with data regarding the thickness of the workpiece to be stapled. The controller then signals cutter box adjustment unit 22 the direction of rotation for spline gear 24 and the amount of rotation to extend or retract cutter box 20 along Arrow D ( FIG. 3 d ) to properly position cutter box 20 . In U.S. Pat. No. 4,318,555, the specification of which is incorporated herein by reference, a means for determining the number of sheets, or thickness, of a stack of workpieces is described and a logic and control means for incrementally advancing the wire for staple forming. Additional devices for determining the height of a stack of sheets may be found in U.S. Pat. Nos. 6,308,951 and 6,773,004 the specifications of which are incorporated herein by reference.
[0044] Referring now to FIGS. 3 a and 3 b, the movement of cutter box adjustment unit 22 in the directions indicated by Arrow M moves unit 22 between an open maintenance position shown in FIG. 3 a and a closed operating position shown in FIG. 3 b. In FIG. 3 b, the engagement between spline gear 24 and cutter box adjustment wheel 26 for movement of cutter box adjustment wheel in response to movement of spline gear 24 is shown.
[0045] Referring now to FIGS. 4 a - d , the cutting stroke of the device 10 will be described. In FIG. 4 b, the staple forming an insertion device 10 is shown in top dead center position of the machine timing which presents the knives 50 a, 50 b of cutter box 20 in closed position as is shown in FIG. 4 a. This closed position of the knives serves to cut the wire into the desired length for the staple to be inserted corresponds to cam follower 42 , mounted on follower arm 43 , being in its lowest position along the length of cam 44 . In achieving this lowered position shown in FIG. 4 b, cam follower 42 will have passed over ridge 46 of cam 44 which actuates a downward stroke of shaft 48 and the closing of knives 50 a, 50 b ( FIG. 4A ) to cut the wire that is to be formed into a staple as it passes between knives 50 a, 50 b.
[0046] It will be appreciated by those skilled in the art that cam 44 is a reciprocating motion cam that is built into bender rail 18 . Thus as bender rail 18 moves in its up and down stroke to form the legs 101 of the staple 100 ( FIG. 1 c ), the cutting of the wire is properly timed to present a cut segment of wire to bender rail 18 for formation of the staple shoulders 105 and legs 101 ( FIG. 1 c ) on the downward stroke of bender rail 18 as will be described hereinafter.
[0047] Referring now to FIGS. 4 c and 4 d, knives 50 a, 50 b are shown in their open position as a result of downward movement of bender rail 18 and driver rail 16 . Drive rail 16 is provided with a cam 52 ( FIG. 4 b ) which provides the repositioning of cam follower 42 to ensure the upward stroke of shaft 48 as cam follower contacts shoulder 53 of cam 52 on driver rail 16 . Through this movement of cams provided on bender rail 18 and driver rail 16 , shaft 48 exhibits reciprocating movement to move knife blades 50 a, 50 b to affect the cutting of the wire as it passes through cutter box 20 . A proximity switch 14 ( FIGS. 1 a and 2 ) is mounted on body 12 to detect the position of driver rail 16 when it is positioned upwardly and when it is positioned downwardly in its stroke.
[0048] As has been previously described, a length of wire is advanced through cutter box 20 by the operation of a wire feeding mechanism providing a length of wire to cutter box 20 . The length of wire provided is then centered with respect to staple forming jig 29 by the movement of cutter box 20 with respect to staple forming jig 29 through the automatic movement of cutter box 20 by cutter box adjustment unit 22 in communication with adjustment wheel 26 . Now with reference to FIGS. 1-6 , the formation of the staple and insertion of the staple into a work piece will be described. Once the wire (not shown) has been advanced through cutter box 20 , it is held in place by wire holding arm 54 which is provided with a magnetized head 55 to hold the wire piece in position with respect to wire forming jig 29 , and in particular, with respect to wire guide grooves 30 within staple forming jig 29 of bender rail 18 . A downward movement of bender rail 18 is then initiated and wire guide grooves 30 of bender rail 18 capture the wire piece therein and press the wire downwardly over shoe 56 to create staple shoulders 105 ( FIG. 1 c ) and legs 101 of staple 100 with crown 103 of staple 100 supported across the face 60 of shoe 56 . This action forms the shoulders 105 and legs 101 of the staple from the wire segment that has been cut by cutter box 20 . This formation of the staple is then followed by a downward movement of driver rail 16 having insertion head 58 mounted thereon which engages staple crown 103 as it is positioned on face 60 of shoe 56 to drive the staple into the work piece.
[0049] Referring now to FIG. 6 , a cross section view of shoe 56 taken along line B-B of FIG. 1 a is shown. The orientation of the structure shown in cross section of FIG. 6 also may be appreciated by viewing the exploded view of the structure in FIG. 1 b . Shoe 56 has a radius face 60 which engages staple crown 103 thereon. It will be appreciated by those skilled in the art that as insertion head 58 attached to driver rail 16 moves downwardly, it contacts face 60 of shoe 56 and staple crown 103 , and as insertion head 58 is pressed downwardly by driver rail 16 , shoe 56 which is spring biased in a position underneath wire guide grooves 30 is forced rearwardly by the downward movement of insertion head 58 , while the radius face 60 of shoe 56 continues the support of crown 103 of staple 100 until insertion head 58 has finished the stroke caused by driver rail 16 and the staple is inserted into the work piece.
[0050] Shoe 56 is also provided with shoe tongue stop 62 on shoe tongue 61 . During the travel of shoe 56 shoe tongue.
[0051] This constant support of staple crown 103 by radius face 60 of shoe 56 during the insertion stroke allows a thinner gauge of wire to be used during the stapling process as less staple strength is required to withstand the force placed upon the staple by insertion head 58 and the contact of the staple with the work piece. This reduction in the wire gauge that is necessary for forming an insertion of a staple within a work piece allows a significant savings to the user of the present invention. For example, each reduction in a gauge size provides 18 percent more wire per pound of metal used to form the wire. For example, it is typically necessary that a 24 to 25 gauge wire be used to form a staple for insertion through a quarter inch of paper product. With the present invention, 27 gauge wire can be used to form a staple that will be insertable within a quarter inch of paper material. Therefore with the present invention, a user may be able to use a gauge of wire for staples which is one, two or three gauge sizes smaller than has previously been used resulting in 18 percent to 54 percent more wire length per pound of metal used to form the wire thus presenting a substantial reduction in cost to the operator.
Wire Incrementing and Advancing Device
[0052] Referring now to FIG. 7-13 , the wire advancing drive 70 or wire incrementing and advancing device 70 of the present invention will be described. First referring to FIG. 8 , wire incrementing and advancing device 70 is shown in partial exploded view. In general, the operation of wire incrementing and advancing device 70 is that a strand of wire 72 is fed to the device by first passing along entry wire guide 74 ( FIG. 10 ) where it is received in feed tubes 76 after which it passes through cleaning pads 78 and into entry guide plate 80 A. Referring to FIGS. 7 and 9 , the wire is then captured between advancement drums 82 a and 82 b which are in operational, facing orientation in FIG. 8 . Drums 82 a, 82 b capture wire 72 and drums 82 a, 82 b rotate to incrementally advance the wire in response to movement of motor 84 . Again, it will be appreciated by those skilled in the art that the signals, similar to those supplied to cutter box adjustment unit 22 , are provided to wire incrementing and advancing device 70 . As is the case with cutter box adjustment unit 22 , a controller is provided with data regarding the thickness of the workpiece to be stapled and the controller signals wire incrementing and advancing device 70 and advancement drums drive motor 83 which then causes the proper incremental rotation of advancement drums 82 a, 82 b to advance the desired length of wire 72 through advancement drums 82 a, 82 b. Wire 72 then passes through apertures 92 in guide plate 80 b and into exit guide 84 ( FIG. 12 ) and into exit guide tubes 86 for communication of the wire to cutter box 20 of staple forming and insertion device 10 .
[0053] Referring now to FIG. 7 wherein a view taken along line J-J of FIG. 8 shows wire advancement drums 82 b. Advancement drums 82 b engage with wire advancement drums 82 a ( FIGS. 8 and 9 ) for frictional capture of wire 72 therebetween. In FIG. 7 , advancement drum compression keys 88 are shown adjacent to wire advancement drums 82 b. Keys 88 may be withdrawn or inserted to effect the compression of advancement drums 82 b against advancement drums 82 a to frictionally capture wire 72 therebetween for advancement as motor 83 rotates shaft 90 upon which drums 82 a,b are mounted. When a key 88 is in the down position the advancement drum 82 b associated with the key is urged against the corresponding advancement drum 82 a to provide a frictional grip of wire 72 as it passes between advancement drums 82 a, 82 b. When a key 88 is in the down position the key provides resistance for spring support pin 91 which resides in void 92 . The resistance provided by key 88 allows contact pressure spring 93 to urge drum block 94 holding advancement drum 82 b therein toward advancement drum 82 a. When key 88 is in the up position, no resistance is provided by key 88 to support spring support pin 91 and the urging of spring 93 is overcome by relief springs 95 a,b which urges drum block 94 holding advancement drum 82 b therein away from advancement drum 82 a.
[0054] Referring now to FIG. 9 , on either side of advancement drums 82 a, 82 b are guide plates 80 a, 80 b. Guide plates 80 a, b are provided with beveled guide voids 92 which permit self threading of wire 72 into plate 80 a and out of beveled guide voids 92 on plate 80 a to thereby position the wire to move across advancement drums 82 a,b and into beveled guide voids 92 on plate 80 b. The configuration of these beveled guides on plates 80 a,b allows the wire to move across advancement drums 82 a,b during loading of the wire and be captured in the opposed guide plate 80 b without operator intervention or with only minimal operator intervention.
[0055] Referring now to FIG. 11 , it will be appreciated that prior to the wire entering the previously described advancement mechanism containing advancement drums 82 a,b that the wire is cleaned by passing the wire across cleaning pads 78 . In FIG. 11 , is shown an exploded view of the cleaning pads 78 as mounted on the device is shown and the wire passes between pads 78 a and 78 b and is cleaned by the frictional contact between the wire and the pads. Once the wire has been advanced by the rotation of the wire advancement drums 82 a,b the wire passes out of plate 80 b and into exit guide 84 for insertion of the wire into tubes 86 which lead the wire to cutter boxes 20 . Exit guide 84 is spring biased against plate 80 b to allow a separation to be caused between exit guide 84 and guide plate 80 b as the wire is loaded.
[0056] In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described.
[0057] Certain changes may be made in embodying the above invention, and in the construction thereof, without departing from the spirit and scope of the invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not meant in a limiting sense.
[0058] Having now described the features, discoveries and principles of the invention, the manner in which the inventive oral fluid collection device is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims.
[0059] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
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A staple-forming and inserting apparatus 10 is provided having an apparatus 22 for movement of the cutter box 20 to allow automatic variations in staple length for one or more staple-forming and inserting apparatus 10 said staple-forming and inserting apparatus 10 being provided with a staple crown 105 supporting shoe 56 to permit supported insertion of the staple into the workpiece the device 10 having blades 50 a , 50 b for pinch-cutting of the staple wire 72 to provide chisel ends to legs 101 of stable 100 device 10 have key and rail construction to allow the operating drive 16 and bender 18 rails to travel on keys 32 that may be replaced to avoid wear on drive 16 and bender 18 rails and replacement of the rails and a floating bender rail 18 that prevents overstrike and damage to knives 50 a, 50 b.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage application of Patent Cooperation Treaty (PCT) Application No. PCT/IB2004/050640 filed May 12, 2004, which in turn claims priority from PCT/SG03/00128 filed May 15, 2003, the contents of which are incorporated by reference herein.
TECHNICAL FIELD
This invention relates to a bus system, and in particular to a bus controller, and to a device incorporating the bus controller.
More particularly, the invention relates to an integrated circuit which can be used as a host controller within an electronic device, in order to improve the efficiency of operation of the device.
BACKGROUND INFORMATION
In a conventional electronic device, operating as a USB host, the processor is able to write data into a system memory. A host controller integrated circuit is then able to read the data directly from the system memory. In order to be able to do this, the host controller needs to master the system memory. However, since the system memory is shared between the host controller integrated circuit and the system processor, this requirement that the host controller be able to master the system memory requires the use of a bus master, which is specific to the system processor. Moreover, while the host controller is mastering the system memory, the core function of the device, running under the control of the system processor, may be disrupted.
BRIEF SUMMARY
According to an aspect of the present invention, a host controller integrated circuit is unable to master the system memory, but instead acts purely as a slave. The embedded processor is then adapted to write the data to the host controller integrated circuit in the form of transfer-based transactions.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention will be described with reference to the accompanying drawings in which:
FIG. 1 is a block schematic diagram of a USB host in accordance with an aspect of the present invention.
FIG. 2 is a block schematic diagram of a host controller in accordance with another aspect of the invention.
FIG. 3 is a block schematic diagram of an alternative form of host controller in accordance with an aspect of the invention.
FIG. 4 illustrates the structure of the memory in the host controller of FIG. 2 or FIG. 3 .
FIG. 5 is an illustration showing the format of software in the device of FIG. 1 .
FIG. 6 illustrates the format of data written from the host microprocessor to the host controller.
FIG. 7 shows the structure of a transfer descriptor header, with which data is transferred.
FIG. 8 is a schematic representation of data to be transmitted, stored in the memory of FIG. 4 .
FIG. 9 illustrates a method by which the data of FIG. 8 may be transmitted.
DETAILED DESCRIPTION
FIG. 1 is a block schematic diagram of the relevant parts of an electronic device 10 , operating as a USB host. The invention is particularly applicable to devices such as mobile phones, or PDAs, in which the functional limitations of the microprocessor and the system memory are more relevant, rather than in personal computers (PCs). However, the invention is applicable to any device which can operate as a USB host.
It will be apparent that the device 10 will have many features, which are not shown in FIG. 1 , since they are not relevant to an understanding of the present invention.
The device 10 has a host microprocessor 20 , which includes a processor core 22 , connected by a standard system bus 23 to a LCD controller 24 , a DMA master 25 , and a memory controller 26 . The memory controller 26 is connected to a system memory 30 by means of a peripheral bus 32 .
A host controller 40 is also connected to the host microprocessor 20 and the system memory 30 , by means of the peripheral bus, or memory bus, 32 . The host controller 40 has an interface for a USB bus 42 , through which it can be connected to multiple USB devices. In this illustrated embodiment, the host controller 40 is a USB 2.0 host controller.
As is conventional, the host controller 40 is adapted to retrieve data which is prepared by the processor 20 in a suitable format, and to transmit the data over the bus interface. In USB communications, there are two categories of data transfer, namely asynchronous transfer and periodic transfer. Control and bulk data are transmitted using asynchronous transfer, and ISO and interrupt data are transmitted using periodic transfer. A Queue Transaction Descriptor (qTD) data structure is used for asynchronous transfer, and an Isochronous Transaction Descriptor (iTD) data structure is used for periodic transfer.
The processor 20 prepares the data in the appropriate structure, and stores it in the system memory 30 , and the host controller 40 must then retrieve the data from the system memory 30 .
FIG. 2 shows in more detail the structure of the embedded USB host controller 40 .
As mentioned above, the host controller 40 has a connection for the memory bus 32 , which is connected to an interface 44 , containing a Memory Mapped Input/Output, a Memory Management Unit, and a Slave DMA Controller. The interface 44 also has a connection 46 for control and interrupt signals, and registers 48 which support the RAM structure and the operational registers of the host controller 40 .
The interface 44 is connected to the on-chip RAM 50 of the host controller, which in this preferred embodiment is a dual port RAM, as will be described in more detail below. The memory 50 is connected to the host controller logic unit 52 , which also contains an interface for the USB bus 42 . Control signals can be sent from the registers 48 to the logic unit 52 on an internal bus 54 .
As mentioned above, the on-chip memory 50 in this case is a dual port RAM, allowing data to be written to and read from the memory simultaneously.
FIG. 3 shows an alternative embodiment of the invention, in which common reference numerals indicate the same features as in FIG. 2 . In this case, the on-chip memory 56 is a single port RAM, and data written to and read from the memory 56 is transferred through an arbiter 58 , which again allows for effectively simultaneous access to the memory 56 .
FIG. 4 shows the structure of the on-chip memory. As far as the structure shown in FIG. 4 is concerned, this is the same whether the on-chip memory is the dual port RAM 50 shown in FIG. 2 , or the single port RAM 56 shown in FIG. 3 .
As shown in FIG. 4 , the RAM is effectively divided into two parts, namely a first part 70 which contains header and status information for the stored transfer descriptors TD 1 , TD 2 , . . . , TDn, and which is itself subdivided into a portion 72 relating to asynchronous (bulk) transfers and a portion 74 relating to periodic (isochronous and interrupt) transfers, and a second part 76 , which contains the payload data for those stored transfer descriptors TD 1 , TD 2 , . . . , TDn.
This structure of the RAM has the advantage that the host microprocessor 20 an easily write and read all of the transfer descriptor headers together. This structure also makes it easy for the headers relating to periodic transfers to be scanned only once in each micro-frame, while headers relating to asynchronous transfers are scanned continuously throughout the micro-frame.
This means that the time between transactions will be small and, equally importantly, it will be consistent from one transaction to another.
FIG. 5 is a schematic diagram showing in part the software operating on the host controller 40 , in order to illustrate the method of operation of the device according to the invention.
The host controller 40 runs USB driver software 80 and USB Enhanced Host Controller Interface software 82 , which are generally conventional.
However, in accordance with the present invention, the host controller 40 also runs USB EHCI interface software 84 , which prepares a list of transfer-based transfer descriptors for every endpoint to which data is to be transmitted.
The EHCI interface software 84 is written such that it uses the parameters which are generated by the EHCI host stack 82 for the existing periodic and asynchronous headers, and can be used for all different forms of USB transfer, in particular high speed USB transfer, such as high speed isochronous, bulk, interrupt and control and start/stop split transactions.
The host microprocessor 20 writes the transfer-based transfer descriptors into the RAM 50 or 56 of the host controller 40 through the peripheral bus 32 , without the host controller 40 requiring to master the bus 32 . In other words, the host controller 40 acts only as a slave. The transfer-based transfer descriptors can then be memory-mapped into the RAM 50 or 56 of the host controller 40 .
Advantageously, the built-in memory 50 or 56 of the host controller 40 is mapped in the host microprocessor 20 , improving the ease with which transactions can be scheduled from the host microprocessor 20 .
Moreover, as described above, the use of a dual-port RAM 50 , or a single-port RAM 56 plus an arbiter 58 , means that, while one transfer-based transfer descriptor is being executed by the host controller 40 , the host microprocessor 20 can be writing data into another block space.
FIG. 6 illustrates the format of one USB frame, divided into multiple micro-frames, in which data is transmitted from the host controller 40 over the USB bus 42 . As is conventional, multiple transactions, including transactions of different transfer types, may be sent within one micro-frame. Again, as is conventional, high speed isochronous transfer is always first, followed by high speed interrupt transfer, and full speed and low speed Start Split and Complete Split transfers, with high speed bulk data occupying the remaining time in the micro-frame.
The transfer-based protocol allows the host microprocessor 20 to write a 1 ms frame of data into the RAM 50 or 56 of the host controller (provided that the RAM is large enough to hold this data), such that this can be transmitted over the USB bus 42 without further intervention from the host microprocessor 20 .
FIG. 7 illustrates the transfer-based protocol for supporting high-speed USB transmissions, with FIG. 7 a showing the format of a 16-byte header of a transfer-based transfer descriptor for one endpoint, in accordance with the protocol, and FIGS. 7 b and 7 c describing the contents of the header fields. The transfer-based protocol header consists of parameters that have the same definition as the conventional USB EHCI software, allowing the transfer descriptors to be easily constructed.
The transfer-based protocol also ensures that data can be sent to each USB endpoint on a fair basis.
FIG. 8 shows a situation in which the payload data associated with a first transfer descriptor TD 1 is divided into three packets, PL 1 , PL 2 and PL 3 , each of 64 bytes; the payload data associated with a second transfer descriptor TD 2 comprises just one packet PL 1 of 32 bytes; the payload data associated with a third transfer descriptor TD 3 is divided into two packets PL 1 and PL 2 , each of 8 bytes; and the payload data associated with a fourth transfer descriptor TD 4 is divided into four packets PL 1 , PL 2 , PL 3 and PL 4 , each of 16 bytes.
FIG. 9 illustrates the method by which these packets of data are transferred out of the RAM 50 , or 56 , to their respective endpoints in respective devices connected to the host.
As indicated by the arrow 90 in FIG. 8 , a cyclical process occurs. Firstly, in step 91 , the first packet PL 1 associated with the first transfer descriptor TD 1 is transferred. The transfer descriptor contains an Active flag which is set high, to indicate that there remains more data associated with this transfer descriptor.
Secondly, in step 92 , the first packet PL 1 associated with the second transfer descriptor TD 2 is transferred. This transfer descriptor now contains an Active flag which is set low by the host controller 40 , indicating that this completes the transfer of the payload data associated with the second transfer descriptor TD 2 .
Next, in steps 93 and 94 , the first packets PL 1 of payload data associated with the third and fourth transfer descriptors TD 3 and TD 4 respectively, are transferred. Again, each of these transfer descriptors contain an Active flag which is set high, indicating that there is more of the payload data associated with each of the transfer descriptors, remaining to be transferred.
Next, in step 95 , the second packet PL 2 of payload data associated with the first transfer descriptor TD 1 is transferred. The Active flag remains high, because there is still more of the payload data associated with that transfer descriptor, remaining to be transferred.
The transfer of the payload data associated with the second transfer descriptor TD 2 has been completed, and so, in step 96 , the second packet PL 2 of payload data associated with the third transfer descriptor TD 3 is transferred. This time, the Active flag in this transfer descriptor is set low, indicating that this completes the transfer of the payload data associated with the third transfer descriptor TD 3 .
In step 97 , the second packet PL 2 of payload data associated with the fourth transfer descriptor TD 4 is transferred, and the Active flag remains high.
In step 98 , the third packet PL 3 of payload data associated with the first transfer descriptor TD 1 is transferred, and the Active flag is set low, indicating that this completes the transfer of payload data associated with the first transfer descriptor.
In steps 99 and 100 , the third and fourth packets PL 3 and PL 4 of payload data associated with the fourth transfer descriptor TD 4 are transmitted, with the Active flag being set low in step 100 , to indicate that this completes the transfer of the payload data associated with the fourth transfer descriptor TD 4 .
During execution of the transfer-based transfer descriptors, the content of the transfer-based transfer descriptors is updated by the host controller logic unit 52 . For example, the Active flag within a transfer descriptor header is set low when the transfer of the payload data associated with the transfer descriptor is completed. The USB EHCI interface software 84 then reformats the updated transfer-based transfer descriptors into a format which can be handled by the conventional EHCI host stack 82 , and the updated transfer-based transfer descriptors are copied back to the system memory 30 .
There is therefore provided a host controller which allows the incorporation of high speed USB host functionality, in particular into non-PC based systems.
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An electronic device, operating as a USB host, has an embedded processor and a system memory, connected by a memory bus. A host controller integrated circuit does not need to master the system memory, but instead acts purely as a slave. The embedded processor is then adapted to write the data to the host controller integrated circuit in the form of transfer-based transactions.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application No. 60/011,347, filed Feb. 8, 1996.
BACKGROUND OF THE INVENTION
This invention relates in general to anti-lock brake systems (ABS) and in particular to a monitoring circuit for an ABS warning lamp.
An Anti-lock Brake System (ABS) is often included as standard equipment on new vehicles. When actuated, the ABS is operative to control the operation of some or all of the vehicle wheel brakes. A typical ABS includes a central control valve having a control valve body. A plurality of solenoid valves are mounted within the control valve body and are connected to the vehicle hydraulic brake system. Usually, a separate hydraulic source, such as a motor driven pump, is included in the ABS for supplying hydraulic pressure to the controlled wheel brakes during an ABS braking cycle. The pump is typically included within the control valve body while the pump motor is mounted upon the exterior of the control valve body. A control module for actuating the solenoid valves and pump is mounted upon the control valve body.
The control module includes electronic components which monitor the speed and deceleration of the controlled wheels. The control module also includes electronic components which are operative to selectively actuate the solenoid valves in the control valve to cyclically relieve and reapply pressure to the controlled wheel brakes when the vehicle brakes are applied and the control module senses an impending wheel lock-up condition. The hydraulic pressure applied to the controlled brakes is adjusted to limit wheel slippage to a safe level while continuing to produce adequate brake torque to decelerate the vehicle as desired by the driver.
A typical ABS also includes a pressure differential switch which monitors the hydraulic fluid pressure within the ABS to assure that the solenoid valves are operating properly. Should failure of a solenoid valve be detected, the pressure differential switch generates a brake component failure signal which is transmitted to the control module. The control module is responsive to the failure signal to illuminate a brake failure warning lamp which is mounted upon the vehicle dashboard. The brake failure warning lamp provides a visual message to the vehicle operator to obtain service for the ABS. It also is known to program the ABS control module to perform diagnostic tests upon the ABS when the vehicle is started. Failure of any of the diagnostic tests will cause the control module to illuminate the brake failure warning lamp.
SUMMARY
The present invention relates to a circuit for monitoring a brake failure warning lamp circuit and generating a failure signal should the warning lamp circuit malfunction.
As described above, it is known to provide a brake failure warning lamp in an ABS equipped vehicle which is illuminated if the ABS malfunctions. However, if the brake warning lamp or its associated warning lamp circuit should fail, the warning function would not be available. Accordingly, it would be desirable to monitor the brake warning lamp and circuit, or driver, for failure.
The present invention contemplates a monitoring circuit which includes a first device for monitoring a condition of the warning lamp driver. The first monitoring device has an output terminal and is responsive to the condition of the warning lamp driver to generate one of a first and a second lamp driver signals at the output terminal.
The monitoring circuit also includes a second device for monitoring a condition of the warning lamp. The second monitoring device has an output terminal and is responsive to the condition of the warning lamp to generate one of a first and a second lamp signals at the output terminal.
The monitoring circuit further includes a decision device having a first input terminal connected to the output terminal of the first monitoring device and a second input terminal connected to the output terminal of the second monitoring device. The decision device further has an output terminal adapted to be connected to a warning device. The decision device is responsive to the lamp driver and lamp signals at the first and second input terminals to generate an output signal at the output terminal.
The invention further contemplates that the first monitoring device is responsive to the voltage across the lamp driver to generate the first lamp driver signal when the lamp driver voltage is greater than a predetermined voltage and to generate the second driver signal when the lamp driver voltage is less than the predetermined voltage.
The invention also contemplates that the second monitoring device is responsive to the current through the warning lamp to generate the first lamp signal when a current flows through the lamp and to generate the second lamp signal when no current is flowing through the lamp.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a monitoring circuit for an ABS warning lamp in accordance with the invention.
FIG. 2 is a truth table for the monitoring circuit shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is illustrated in FIG. 1 a schematic drawing of a monitoring circuit 10 for an ABS warning lamp in accordance with the invention. Also shown in FIG. 1 is a warning lamp circuit 11 which is of conventional design. The warning lamp circuit 11 includes a warning lamp 12 which is typically mounted in the vehicle dashboard. The warning lamp 12 is connected between a power supply 13, such as the vehicle battery, and a lamp driver 14. The lamp driver 14 is usually an electronic switch which is operative upon receipt of a brake component failure signal to connect the warning lamp 12 to ground 15. In the preferred embodiment of the invention, the lamp driver 14 is an n-channel MOSFET 20, as shown in FIG. 1. However, it will be appreciated that other electronic or mechanical devices may be used as the lamp driver 14.
The MOSFET 20, which is usually included in an ABS control module (not shown), has a drain terminal 21 connected to the warning lamp 12 and, in the conventional warning lamp circuit (not shown), has a source terminal 22 connected through the monitoring circuit 10 to ground 15 to ground. The MOSFET 20 also has a gate terminal 23 which is connected to the control module electronics (not shown). The MOSFET 20 is an electronic device which is in a non-conducting, or "off", state with no current flow between the drain and source terminals 21 and 22 when the gate terminal 23 is at ground potential. Upon application of a positive potential to the gate terminal 23, the MOSFET 20 switches to a conducting, or "on", state, allowing current to flow between the drain and source terminals 21 and 22.
During normal ABS operation, the MOSFET gate terminal 23 is held at ground potential, and the off state of the MOSFET 20 blocks any current flow through the warning lamp 12. Upon detection of a fault in the ABS, the control module electronics applies a brake component failure signal, which, for the circuit illustrated is a positive voltage, to the MOSFET gate terminal 23. The MOSFET 20 is responsive to the brake component failure signal to switch to its on state, allowing current to flow from the power supply 13, through the warning lamp 12 and, as will be explained below, the monitoring circuit 10 to ground 15. This illuminates the warning lamp 12, which remains illuminated as long as there is a failure signal present at the MOSFET gate terminal 23.
The monitoring circuit 10 includes a voltage sensing operational amplifier 30 for monitoring the voltage across the lamp driver 14. The voltage sensing operational amplifier 30 has a negative input terminal 31 connected to the MOSFET drain terminal 21 and a positive input terminal 32 connected to a reference voltage supply 33. The reference voltage supply 33 has a predetermined voltage value which is selected to be less than the output voltage of the power supply 13, but greater than the voltage at the MOSFET drain terminal 21 when the warning lamp 12 is illuminated and the warning light circuit 11 is operating properly.
The voltage sensing operational amplifier 30 also has an output terminal 35. When the voltage at the MOSFET drain terminal 21 is greater than the reference voltage, the operational amplifier 30 is off and the output terminal 35 is at ground potential. If the drain voltage drops below the reference voltage, a positive voltage difference appears between the operational amplifier input terminals 31 and 32 and the operational amplifier 30 turns on, which causes a positive voltage, typically 5 volts, to appear at the output terminal 35.
The monitoring circuit 10 also includes a current sensing operational amplifier 40 for monitoring the current flowing through the warning lamp circuit 11. The current sensing operational amplifier 40 has a positive input terminal 41 connected to the MOSFET source terminal 22 and a negative input terminal 42 connected to the ground 15. A current sensing resistor 43 is connected between the operational amplifier input terminals 41 and 42. The current sensing resistor 43 has a small value, typically a few ohms. As shown in FIG. 1, the warning lamp current normally flows through the current sensing resistor 43.
The current sensing operational amplifier 40 also has an output terminal 45. The voltage at the operational amplifier output terminal 45 is a function of the lamp current. When the MOSFET 20 is in its off state, the lamp current is zero and there is no voltage across the sensing resistor 43. Accordingly, the current sensing operational amplifier 40 is off and the output terminal 45 is at ground potential. When the lamp driver 14 is in its conducting state, a lamp current flows through the sensing resistor 43 causing a voltage to appear across the operational amplifier input terminals 41 and 42. Accordingly, the operational amplifier 40 turns on, which causes a positive voltage, typically 5 volts, to appear at the output terminal 45.
The monitoring circuit 10 further includes an exclusive OR, or XOR, gate 50. The XOR gate 50 has first and second input terminals, 51 and 52, respectively. The first input terminal 51 is connected to the output terminal 35 of the voltage sensing operational amplifier 30 while the second input terminal 52 is connected to the output terminal 45 of the current sensing operational amplifier 40. The XOR gate 50 also has an output terminal 55 which is connected to a vehicle status monitor, such as a vehicle diagnostic computer and/or another warning light (not shown). The XOR gate 50 is operative to generate a positive voltage, typically 5 volts, as a warning light failure signal when the input terminals 51 and 52 are at different potentials. When the input terminals 51 and 52 are at the same potential, which, as described above, can be either zero or 5 volts, the output terminal 55 goes to ground potential.
The operation of the warning lamp monitoring circuit 10 will now be described. When the MOSFET 20 and lamp 12 are functioning properly, the lamp 12 will be illuminated when the MOSFET 20 is in its on state and the lamp 12 will not be illuminated when the MOSFET 20 is in its off state. As illustrated in the first line of the truth table shown in FIG. 2, when both the lamp 12 and MOSFET 20 are on, there is a current flowing through the warning lamp circuit 11 and the voltage at the drain terminal 21 drops below the reference voltage. Also, a voltage appears across the current sensing resistor 43. As a result, both operational amplifiers 30 and 40 turn on and apply five volts to both of the input terminals 51 and 52 of the XOR gate 50. The XOR gate 50 is responsive to both of the input voltages being the same to hold the XOR gate output terminal at ground potential.
Similarly, as shown in the second line of the truth table in FIG. 2, when both the lamp 12 and MOSFET 20 are off, there is no current flowing through the warning lamp circuit 11. Accordingly, the voltage at the drain terminal 21 is approximately equal to the output voltage of the power supply 13, which is greater than the reference voltage. Also, there is no voltage across the current sensing resistor 43. As a result, both operational amplifiers 30 and 40 turn off and hold both of the input terminals 51 and 52 of the XOR gate 50 at ground potential. The XOR gate 50 is responsive to the two input voltages being the same to continue to hold the XOR gate output terminal at ground potential, as shown in the second line of the truth table.
A potential fault in the warning lamp circuit 11 is an open circuit occurring at the drain terminal 21 of the MOSFET 20. For example, such a fault could occur if the warning lamp 12 burned out. With an open circuit between the drain terminal 21 and the power supply 13, there would be no voltage at the negative input terminal 31 of the voltage sensing operational amplifier 30. Accordingly, the voltage sensing operational amplifier 30 would be on and would apply 5 volts to the first input terminal 51 of the XOR gate 50. This would occur when the MOSFET 20 is in either its on state or its off state, as shown in lines 3 and 4 in the truth table. Because there is an open circuit, no current would flow through the current sensing resistor 43. Accordingly, the current sensing operational amplifier 30 would be off and would hold the second input terminal 52 of the XOR gate 50 at ground potential. Thus, the input voltages to the XOR gate 50 are different and the XOR gate 50 will generate a 5 volt warning light failure signal at its output terminal 55. As described above, the warning light failure signal would be applied to a vehicle status monitor, such as a vehicle diagnostic computer and/or another warning light.
Another potential fault which could develop in the warning lamp circuit 11 is a short from the MOSFET drain terminal 21 to ground 15. Such a fault could, for example, result from a wiring fault and would cause the lamp 12 to be continually illuminated while bypassing the current sensing resistor 43. Accordingly, the voltage at the MOSFET drain terminal 21 would be effectively zero, causing the voltage sensing operational amplifier 30 to turn on and apply 5 volts to the first input terminal 51 of the XOR gate 50. This would occur whether the MOSFET 20 were in either its on state or its off state, as shown in lines 5 and 6 in the truth table. Additionally, because the current sensing resistor 43 is bypassed, the current sensing operational amplifier 40 is shut off, holding the second input terminal 52 of the XOR gate 50 to ground potential. As a result, the inputs to the XOR gate 50 are different and the XOR gate 50 will generate a 5 volt warning light failure signal at its output terminal 55, as shown in lines 5 and 6 in the truth table.
A third potential fault in the warning lamp circuit 11 is the occurrence of a short from the voltage supply 13 to the drain terminal 21, as could occur with short in the wiring or due to moisture in the lamp socket. Such a fault would provide a current path which bypasses the lamp 12 and connects the drain terminal 21 of the lamp driver 14 directly to the power supply 13. Because the power supply voltage is greater than the reference voltage, the voltage sensing operational amplifier 30 would be off and would hold the first input terminal 51 of the XOR gate 50 at ground potential. If the MOSFET 21 is in its on state, current will flow from the drain terminal 21 through the sensing resistor 43, causing the current sensing operational amplifier 40 to turn on and apply 5 volts to the second input terminal 52 of the XOR gate 50. Accordingly, as shown in line 7 of the truth table, the XOR gate 50 will generate a 5 volt warning light failure signal at its output terminal 55.
Conversely, if the MOSFET 21 is in its off state, current will not flow through the current sensing resistor 43, causing the current sensing operational amplifier 40 to shut off. The voltage sensing operational amplifier will remain off and both input terminals of the XOR gate 50 will be at ground potential, as shown in line 8 of the truth table. Accordingly, the output terminal 55 of the XOR gate 50 will be at ground potential. Since both input voltages to the XOR gate 50 are the same, the XOR gate output terminal 55 will be held at ground potential. However, these conditions are the same as shown in the second line of the truth table for correct operation. Therefore, the combination of a short from the power supply 13 to the drain terminal 21 does not generate a warning light failure signal when the MOSFET 20 is off.
It is apparent from the above description that the monitoring circuit 10 continuously monitors the condition of the warning lamp 12 and circuit 11, including periods when the ABS is not operative.
While the preferred embodiment of the invention has been illustrated and described in terms of monitoring an ABS warning lamp and associated circuit, it will be appreciated that the invention also can be utilized to monitor other lamps and lamp circuits.
In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.
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A monitoring circuit for detecting a malfunctioning warning lamp circuit includes a first device for monitoring the voltage within the warning lamp circuit and a second device for monitoring the current through the warning lamp circuit. Each of the monitoring devices has an output which is connected to a decision device. The first device generates a first output signal when the monitored voltage is greater than a predetermined voltage and a second output signal when the monitored voltage is less than the predetermined voltage. The second device generates a first output signal when a current flows through the lamp and a second output signal when there is no current flowing through the lamp. The decision device is responsive to the output signals from the monitoring devices to generate a failure signal when the warning lamp circuit malfunctions.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. Application Ser. No. 557,472 filed Dec. 2, 1983 now U.S. Pat. No. 4,537,303.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a batch pack for silver filings for the preparation of a dental amalgam in a laboratory mixing apparatus. More particularly, this invention relates to a foil bag which is inserted in a mixing chamber and exposed to mixing vibration for releasing the contents of the foil bag under the action of the mixing vibration.
In U.S. Pat. No. 4,306,651 issued to the present applicant which patent disclosure is incorporated herein by reference, a multi-component capsule for dental purposes is shown wherein one component is freely contained in the mixing chamber of the capsule and the other component is contained in the foil bag and thereby separated from the one component until the foil bag is destroyed by the mixing vibration. Naturally, it is sufficient to enclose merely one component in a bag so as to insure chemical separation during the storage period. The use of a multi-component capsule for storage and for a single mixing operation involves a certain expenditure which can be avoided where the dentist places silver powder as well as, by means of a dosing apparatus, a corresponding quantity of mercury into a mixing capsule for multiple use, closes the capsule and subsequently mixes the components in a vibration apparatus. While this method is less expensive, inexact dosages may result more readily than with a mechanical pre-dosing, and the physician is exposed to the immediate influence of the mercury.
The present invention concerns the problem of combining the simplicity of the method as known from the use of disposable capsules with the low expenditure involved in the repeated use of the capsule. A solution according to the invention resides in the fact that the powdery component is also enclosed in a separate foil bag which is exposed to vibration and opens under the action of the mixing vibration, with the foil bag consisting of a material having a specific gravity several times lower than that of the powdery component.
The enclosure of both components in respective foil bags permits their optional use, irrespective of whether they are supplied in a disposable capsule or whether they will be inserted by the dentist into a mixing capsule to be used if necessary several times. Furthermore, the enclosure of both components permits an easy and simple dosing by inserting in each case such a number of foil bags containing the components into a mixing capsule in accordance with the desired amalgam amount.
Powder would not be expected to liberate itself sufficiently completely from a foil bag which opens under mixing vibration since such characteristics cannot be expected even of the liquid component under certain conditions. For example, there is the possibility that mercury will not be distributed completely from a sealed metal foil bag as disclosed in U.S. Pat. No. 4,182,447. If the complete emptying of the foil bag appears not to be insured even with liquids under certain conditions, then this would much less be expected as regards the storage of a powder in a foil bag. It is more surprising that the complete discharge of the powdery component is achieved if in accordance with the present invention the specific gravity of the bag material is several times lower than that of the powder. It may be assumed that this effect is due to the fact that in accordance with the physical law of force equals mass times acceleration, the forces exerted by the various vibration accelerations and the substances contained in the capsule are considerably smaller in relation to the specifically lighter bag material than in relation to the powder particles so that the latter is separated from each other by the very different forces acting on them. It may also be of importance in this connection that under vibration conditions the powder does not behave as solid material but behaves very similar to a liquid. This latter characteristic is due to the fact that powder particles get into a relative motion with respect to each other whereby air layers are enclosed between them which terminate the solid connection and put the powder as a whole into a so-called fluidized state, which state is known as being used in another technical field, namely that of the mechanical conveying and handling of powdery material.
It can easily be determined by experiments by how many times the specific gravity of the powder must be greater than that of the bag material. There is to be achieved a density ratio, relative to the solid powder material, of at least 5 and preferably of more than 8.
The invention relates furthermore to a mixing capsule for carrying out the stated method of the vibration mixing of several components contained therein particularly for dental purposes. The mixing capsule contains in a mixing chamber a liquid component tightly enclosed in a foil bag for releasing said component under the action of mixing vibration in a powdery component. The powdery component is contained in a separate foil bag which opens under the action of the mixing vibration with the foil bag consisting of a material having a specific gravity several times less than that of the powdery component by a factor of at least 5 and preferably more than 8.
Finally, this invention relates to a portion package for silver powder or the like powdery dental material intended for a vibration mixing in a dental mixing capsule. In the package, the powder is enclosed in a foil bag, the material of which is specifically several times lighter than the powder and the strength of which is predetermined such that it opens under the action of the mixing vibration in the mixing chamber of the dental mixing capsule.
The enclosure of the powder, particularly the silver powder or the silver filings, in a foil bag has a great advantage that the portion size can be pre-determined with great exactness. Dental amalgam is prepared by the dentist from silver filings and mercury to obtain a more accurate dosage. It is known to prepare batch packs of the two components, which batch packs are together introduced into a mixing capsule which is exposed in a mixing apparatus to a mixing vibration of, for example, 300 Hz. Known batch units for the silver filings consists of pellet-shaped pressings which are supplied loose in a relatively large number in a suitable packaging container. To prevent an excessive loss of their weight due to mutual attrition and to enable them to be handled without a risk of breakage, the pellet-shaped tablets are compressed to a high density which approaches the density of the solid metal to within a few percent. Nevertheless, the formed tablets can suffer an undesirably large weight loss due to attrition, particularly if the tablets are inexpertly handled and remain for a long time in the common container. The tablets also have the disadvantage that under the action of vibration in the mixing capsule the tablets disintegrate sufficiently into reactive powder only in the presence of a pestle.
It is also known to store such tablets in a foil bag such as disclosed in European Published Application 83 106110 wherein at least the attrition loss is eliminated but the need for a pestle is not avoided. Moreover, it is known to introduce the silver filings in the form of a powder into the foil bag. This latter configuration has the advantage that the silver filings are available immediately in the reactive form. Nevertheless, a pestle is required in most cases, namely in order to accomplish destruction of the foil bag. Even though the foil bag can be made so thin that even without a pestle it tears under the acceleration forces exerted by the powder and the adjacent mercury during the mixing vibration, the use of somewhat thicker foil is frequently desirable in order to provide greater safety for good separation of the components and against the formation of relatively small foil residues which might make clean removal of the amalgam more difficult.
It is therefore an object of the present invention to provide a batch pack for silver filings for the preparation of dental amalgam in a laboratory mixing apparatus which is easier to handle. In accordance with the present invention the silver filings are pressed into a briquette for enclosure within the foil package. The density of the briquette is not more than approximately 8 gram/cm 3 and preferably not more than 7.5 gram/cm 3 . The density of the pore volume of the briquette is at least approximately 20 percent.
According to a further feature of the present invention, portion packages of the dental material components to be used together can be connected to each other. This presents not only the advantage that the use is simplified since in each case only one portion of the package with both components needs to be inserted in the mixing capsule but also the portioning becomes more reliable since no mistakes can occur in the coordination of component amounts suited to each other. Additionally, several portion packages can be inserted in the mixing capsule at a time, such as for a large tooth filling wherein there is required an amalgam amount greater than that provided by one portion package.
The connection of the two individual portion packages to a common portion package can be achieved in a simple way, e.g., by adhesion bonding. According to another feature of the present invention, the connection between the individual portion packages is obtained in that at least one foil is in involved in the formation of both portion packages. Preferably, even both portion packages are formed integrally by a pair of foils, which are welded together in forming two separate portion pockets.
According to a further embodiment of the invention, two cover foils are welded together with a central foil to form two portion pockets situated on both sides of the central foil.
The destruction of the foil bag containing the liquid component is facilitated by the powdery component being packed in a foil bag combined as a unit with the liquid bag, since the entire powder material substantially simultaneously exerts impact on the liquid bag and thus a stronger effect thereon than simply a powder distributed in the entire space.
There may be provided devices which improve the opening of the foils under the action of the mixing vibration and/or the mixing effect, for example a pestle, which may also be contained in the portion package, or edges or prongs projecting inwards from the wall of the mixing chamber.
If a capsule is to be used repeatedly for the preparation of a dental amalgam, the capsule must be cleaned between individual applications or at least from time to time. Furthermore, the capsule has to be considered a disadvantage in that the prepared mixture must be taken out of the capsule in a relatively complicated way, and in which respect also the remainders of the consumed packaged, likewise contained in the capsule, can be inconvenient. Such a disadvantage can be avoided in accordance with the present invention in that the package foil, destructible by the action of the mixing vibration, together with the portion chamber separated therefrom and including the dental material components, is enclosed by a package casing not destructible by the action of the mixing vibration.
After the mixing process, the mixed material is now contained in the free form within the mixing chamber of the mixing capsule but is still enclosed by the foil bag, wherein merely the inner separating foil has been destroyed. One can therefore simply take the closed portion package out of the mixing capsule, tear the portion package open and take out the mixture by a spatula or squeeze the mixture out between two fingers. Thus, the removal of the mixture is substantially simplified and is achieved without special measures in a fashion wherein the mixture remains hygenic.
The arrangement of the package foil destructible by the mixing vibration with respect to the non-destructible packaging casing can be different. In one advantageous embodiment there are provided for example two foil bags, one of which freely encloses as a covering foil bag the first dental component as well as the destructible foil bag containing the second dental material component. In accordance with another expedient embodiment, it is provided that two foils, together forming the covering foil bag, are welded together on both sides of the destructible foil either to the latter or to each other.
After mixing, the outer package casing which is not destructible by the mixing vibration forms a container for the mixed dental material. In order that the container can be handled more easily, it can be formed according to the invention as a semi-flexible cup-like package portion. The term semi-flexible means that the container retains the cup-shape in a more or less deformed state even if it is held between the fingers in order to be emptied. Its cup-shape facilitates the removal of the mixed material.
Additionally, it may be provided according to the present invention that the package casing is provided with an opening device. An opening device is understood to mean those elements or formations which enable or facilitate the opening process. This includes, for example, gripping lugs projecting outwards from the portions forming the actual package casings so as to allow, for the purpose of opening, a gripping thereof in the exertion of a force. Furthermore, this includes ideal tearing points in notches in the welding edge in which the opening tear may be started.
The portion package according to the present invention can enclose the dental material components without a substantial empty space so that the mixing forces created upon the impact of the portion package during the mixing vibration at the ends of the mixing capsule will be transferred, without being damped, onto the dental material components to be mixed. This applies particularly of a flexible material as used for the non-destructible package casing, which completely transmits the forces to the dental material. Instead of this, it may, however, also be provided that the portion package includes a certain empty space permitting a certain vortexing. This applies particularly if the package casing consists wholly or partially of a semi-flexible or stiffer material.
It may also be expedient that the portion package contains a pestle, i.e., a body of for instance glass, ceramics, synthetic material, which due to its movement within the portion package, caused by the mixing vibration, assists in the mixing of the components. It is not necessary that the two component bags are inserted in the mixing capsule only by the dentist and immediately prior to use, but the invention rather presents also the advantage that the filling of the capsule becomes independent of the dosing and encasing of the components. Finally, there is achieved an advantage wherein it is not necessary to tightly close the capsule, even if the latter is intended for long term storage, such that the components in their bag packages can be sufficiently sealed against atmospheric influences and evaporation of poisonous gases into the atmosphere is prevented.
The foil packages may be provided with imprints, i.e., with statements required under the drug law, such as the name of the manufacturer, weight, durability, date of filing, specification of the materials, etc. The individual foil packages can be lined up as double packages or individually within a strip of similar packages and can be separable from each other and, if necessary, from the strip section provided with the information by perforation or pre-determined breaking points, respectively.
The invention presents considerable price advantages over the known disposable capsules, which mostly have to be additionally prepared for mixture by turning, pressing, or screwing. The encasing of the amalgam powder in foil bags can also be advantageous over the processing in the form of tablets since the latter first have to be compressed which involves cost. Moreover, it can be disadvantageous for some amalgam powders to be compressed tablets. Finally, the abrasion of the tablets may lead to differences in weight. Compared with the use of automatic mixers, the invention involves the advantages of a greater exactness, the amalgams of any kind can be used, so that no maintenance of the apparati is required and so that the dentist is not exposed to mercury vapor.
The portion package of the components to be mixed can be inserted in the mixing capsule at any point of the chain between production, storage and use.
In the context of the invention, both the mixing capsule and the vibration mixers used for dental purposes can be considered to be known. Mixing capsules are elongated containers closed by a removable lid having a length in the order of 3 cm and a diameter on the order of 1 cm. The mixers are formed so that the mixing capsules inserted therein can be reciprocated in their longitudinal direction at a frequency of 300 Hz so that the material contained in the interior of the capsule (the mixing chamber) is flung to and fro between the end walls of the mixing chamber. The volume of the material amounts to only a very small portion of the volume of the mixing chamber. Typical amalgam portions as they are prepared by the dentist in one mixing operation lie between 0.5 grams and 1 gram.
With respect to foil materials, they are particularly suitable synthetic materials, e.g., a polyethelyne foil of thickness on the order of magnitude of 0.05 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section through a mixing capsule in about normal size;
FIG. 2 is a portion package with two individual portion packages connected by gluing;
FIG. 3 is a side elevation view of a portion package connected to form one piece;
FIG. 4 is a top plan view of a portion package connected to form one piece;
FIG. 5 is a third embodiment of the present invention;
FIG. 6 is a package strip comprising several double portion packages separable from each other;
FIG. 7 is a fourth embodiment of the present invention on an enlarged scale;
FIG. 8 is a fifth embodiment of the portion package of the present invention on an enlarged scale;
FIG. 9 is a top plan view of the sixth embodiment of the portion package;
FIG. 10 is a section view corresponding to FIG. 7 through the sixth embodiment of the package after mixture thereof;
FIG. 11 is a seventh embodiment of the present invention with two bags, one disposed within the other;
FIG. 12 illustrates the embodiment of FIG. 6 after completion of a mixing operation thereof;
FIG. 13 is a perspective illustration of the eighth embodiment of the present invention; and
FIG. 14 is a sectional view of an eighth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The mixing capsule 1 consists of a container portion 2 and a removable lid 3 which is fittingly arranged thereon and can, if necessary, be closed again. The elements together enclose the mixing chamber 4 in which a portion package 5 is disposed which comprises respective portion pockets for matching amounts of mercury and silver powder or filings. By vibration of the capsule in a mixer (not illustrated) in the direction of the arrow 6, the portion package 5 is alternately caused to vigorously impact on both front surfaces of the mixing chamber 4. The packing casing is torn up during the impact to release the contents so that the mixing of the components can take place. In order to facilitate the tearing up of the packing casing and if necessary also the mixing process, one front surface comprises, at 7, a pointed projection extending into the mixing chamber.
According to FIG. 2, the portion package consists of two individual packages 8, 9, for silver and mercury, respectively, which packages are connected to each other by adhesion bonding 10. The silver powder or the silver filings can be contained therein in the form of powder or also as shown at 11 by dotted lines, in the form of a tablet or a briquette. The briquette of silver filings is compressed to have a density of not more than approximately 8 g/cm 3 and preferably not more than 7.5 g/cm 3 . This latter relationship corresponds to a difference, relative to the density of the solid metal form of silver of 17-22 percent pore volume contained in the briquette. The density can therefore also be defined by the relationship wherein the pore volume of the briquette is at least approximately 20 percent.
Surprisingly, the lower density of the briquette form has the consequence that the use of a pestle becomes unnecessary. On the one hand, the compressive strength of the briquette is sufficient for it to act as a unitary impact body when the point is the destruction of the foil surrounding. On the other hand, the compressive strength is so low that the acceleration forces which arise during the mixing vibration are sufficient for disintegrating the briquette into a reactive powder. The compressive strength (measured in the direction of the diameter of a specimen pellet of 2 mm height and a 6 mm diameter) is not greater than about 50 newtons. Typically the compressive strength is on the order of magnitude of approximately 40 newtons. By contrast, the compressive strength of the known tablets is at least about twice as large.
While low density of the briquettes can have the result that on mechanical handing of the briquettes, the briquettes suffer weight losses due to attrition or breakage, the latter can easily be avoided by an appropriate gentle treatment of the briquettes during the handling in the factory before packaging. It is, of course, immaterial after the briquettes have been enclosed in the foil bag.
In one example of a briquette of silver filings in accordance with the present invention, the commercially available silver filings have the following composition:
SILVER--68% BY WEIGHT
TIN--26% BY WEIGHT
COPPER AND ZINC--REMAINDER
The foregoing filings are compressed to form briquettes or tablets which are defined by two mutually parallel surfaces and cylindrical surfaces perpendicular thereto. The diameter is 6 mm, the height is 2 or 3 mm and the weight is 400 or 600 mg, respectively. A compressive force of about 10 KN is applied to compress the filings into the foregoing briquettes. The compressive force results in a density of 7.1 g/cm 3 . The compressive strength between the two plates acting diametrically on the cylinder surface is 40 newtons. The briquettes or tablets formed in accordance with the invention were sealed in foil bags of Surlyn film having a film thickness of 0.05 to 0.07 mm.
By contrast, known tablets or briquettes of the same weight as the foregoing examples have a height of 1.5 or 2.5 mm and are compressed with a pressure force of about 20 KN and have a compressive strength of around 100 N.
A batch pack incorporating the foregoing examples of briquettes of silver filings together with a corresponding mercury batch pack was subject, in a customary elongate mixing capsule in a commercially available laboratory mixing apparatus to a vibration of 300 Hz in the longitudinal direction of the capsule. The foil bag surrounding the briquette was opened by vibration without being torn into small pieces. The briquette disintegrated into powder and was perfectly mixed with the mercury.
The batch pack as described above can even from the factory be marketed together with corresponding mercury batches or mercury batch packs in mixing capsules which are then used as disposable mixing capsules. Instead, it is also possible to sell the batch pack according to the invention individually, namely in the form of a multiplicity of such batch packs in a common container, for example, in the way hitherto conventional for individual briquettes of silver filings. The batch pack together with the mercury is then introduced by the dentist into a mixing capsule which can be used several times.
The second embodiment of the portion package according to FIGS. 3, 4 consists of two foils 12, 13 which are welded together in closed circles 14 to form tight portion pockets 15 for respectively receiving the silver powder or filings and the mercury or other dental materials.
In the third embodiment according to FIG. 5, only one foil 16 is formed to be continuous, whereas the portion pockets 17 thereon are formed by individually cut-out foil pieces 18 and a welding corresponding to FIG. 4.
The portion packages according to FIGS. 3 and 5 can be kept in stock in the form of packaged strips according to FIG. 6, wherein the portion packages, each of which consists of two individual packages for the two components, can be easily separated from each other by means of a perforation 19.
In the fourth embodiment according to FIG. 7, two covering foils 21, 23 are circumferentially tightly welded in the area 24 to a central foil 22 to form two portion pockets 20, 30. At least three of the foils are designed such that they become destroyed under the action of the mixing vibration and will release the contents. In FIG. 7, it is moreover shown that the portion package can comprise a pestle 31, for instance, in an inert plastic or glass piece in one of the portion pockets.
A fifth embodiment, similar to the embodiment according to FIG. 7, is shown in FIG. 8, with the difference that the central foil 26 is welded separately to the covering foil 25 at 27, while the other covering foil 28 is welded to the covering foil 25 at a distance from the welding seam 27 at 29. All welding seams are effected circumferentially so that the pockets 20, 30 are completely closed. The spacing of the welding seams 27, 29 presents the advantage that they can be effected separately as to time and space.
Of course, the portion packages according to FIG. 2 or 7 or 8 can also be combined in a plurality thereof to package strips according to FIG. 6 so as to be separable from each other.
It is, of course, not necessary that in each portion package all foils serving for its formation are destructible under the action of the mixing vibration, but it is sufficient if in each case one foil used in the formation of each portion package is destructible. In many cases, it is also sufficient if only one of these foils has a specific gravity several times lower than that of the powder component, even though expediently both foils used for forming the portion pockets provided for receiving the powder should comply with this requirement.
According to a sixth embodiment, which may be described likewise by reference to FIGS. 7 and 8, the covering foils 21 and 23 or 25 and 28, respectively together form a package casing not destructible by the mixing vibration while the central foil separating the portion pockets 20, 30 is made such that it tears under the action of the mixing vibration, whereby, in accordance with FIG. 10, the two components can together be mixed by the vibration. The welding seam can form, according to FIG. 9, two adjacent, outwardly projecting lugs 33, between which a slot or a notch is provided. By pulling the lugs 33 in different directions, it is possible, starting from the notch 34 to tear up the bag after mixture in order to enable the removal of the contents.
In the seventh embodiment according to FIGS. 11 and 12, there is, apart from the silver powder 37 freely housed in the package casing 36 consisting of two foils welded together and not being destructible by mixing vibration, also a second package bag 38, which consists of the foil destructible by the mixing vibration and containing the mercury. During the mixing vibration, the bag according to FIG. 12 is destroyed so that the two components come into contact.
The foils which form the package casing in FIGS. 7-12 can be soft so that they do not tend to assume a specific configuration. After opening, the contents may be squeezed out of the packages. However, it is also possible instead of the latter that one of the two encasing foils is more rigid so as to form, after separation of the other encasing foil and, if necessary, of the separating foil, a dish or cup-shaped container, of which the mixed material can more easily be removed. In that case, the opening devices are expediently formed such that it is possible to pull off one encasing foil like a lid, along the corresponding weaker welding seam, from the edge of the other encasing foil which is formed as a dish or cup. The embodiment according to FIGS. 13 and 14 likewise follows the latter principle, wherein the markedly cup-shaped portion 48 of the package encasing is relatively rigid, while the covering foil 49 which is welded on to the rim of the cup portion 48 along the welding seam 50 and enclosing the separating foil 51, can be flat. The covering foil and the cup portion 48 are provided at their rim with lug-like projections 52, 53, which can be gripped so as to enable the pulling off of the covering foil from the rim of the cup portion 48. In this connection, the arrangement can be such that the separating foil 51 (in deviation from the illustration) is connected exclusively to the covering foil 49 or that the common welding seam of all three foils is weakest between the separating foil 51 and the rim of the cup portion 48 so that, when pulling off the covering foil 49 there will be simultaneously separated also the remainders of the separating foil from the cup portion 48.
The cup portion 48 can be made rather large with respect to the volume of the components to be mixed, so that there remains a gas filled space, in which the components to be mixed can be hurled around with the mixing-improved effect when the package hits upon the ends of the mixing capsule. For improving the mixing effect, a pestle 54 can be additionally inserted. If reference is made in the claims to the cup-shape, such reference should include also similar forms such as the dish shape in accordance with FIG. 7.
In the sixth to eighth embodiments, the foil which is destructable by the mixing vibration has expediently likewise a specific gravity several times lower than that of the powdery dental material, although these embodiments can be used also with materials having a specific gravity in the same order or even lower than that of the foil, for instance, with the components or fillers for synthetic resinous dental materials.
While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present invention.
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A batch pack for silver filings is employed in the preparation of dental amalgam in a laboratory mixing apparatus. The batch pack comprises a foil bag which can be destroyed by the mixing vibration and a briquette or tablet of silver filings. The density of the briquette of silver filings is not more than about 8 gram per cubic centimeters or a pore volume of about 20 percent of the volume of the briquette.
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BACKGROUND
Various types of hearing prostheses provide persons with different types of hearing loss with the ability to perceive sound. Hearing loss may be conductive, sensorineural, or some combination of both conductive and sensorineural hearing loss. Conductive hearing loss typically results from a dysfunction in any of the mechanisms that ordinarily conduct sound waves through the outer ear, the eardrum, or the bones of the middle ear. Sensorineural hearing loss typically results from a dysfunction in the inner ear, including the cochlea where sound vibrations are converted into neural signals, or any other part of the ear, auditory nerve, or brain that may process the neural signals.
Persons with certain forms of conductive hearing loss may benefit from hearing prostheses, such as acoustic hearing aids or vibration-based hearing aids. An acoustic hearing aid typically includes a small microphone to detect sound, an amplifier to amplify certain portions of the detected sound, and a small speaker to transmit the amplified sounds into the person's ear. Vibration-based hearing aids typically include a small microphone to detect sound, and a vibration mechanism to apply vibrations corresponding to the detected sound to a person's bone, thereby causing vibrations in the person's inner ear, thus bypassing the person's auditory canal and middle ear.
Persons with certain forms of sensorineural hearing loss may benefit from cochlear implants and/or auditory brainstem implants. For example, cochlear implants provide a person having sensorineural hearing loss with the ability to perceive sound by stimulating the person's auditory nerve via an electrode array implanted in the person's cochlea. In traditional cochlear implant systems, an external component of the cochlear implant detects sound waves, which are converted into a series of electrical stimulation signals delivered to the implant recipient's cochlea via the electrode array. Electrically stimulating auditory nerves in a cochlea with a cochlear implant enables persons with sensorineural hearing loss to perceive sound.
A traditional cochlear implant system includes an external speech processor unit worn on the body of a prosthesis recipient and a stimulator unit implanted in the mastoid bone of the recipient. In this traditional configuration, the external speech processor unit detects external sound and converts the detected sound into a coded signal through a suitable speech processing strategy. The coded signal is sent to the implanted stimulator unit via a transcutaneous link. The stimulator unit (i) processes the coded signal, (ii) generates a series of stimulation signals based on the coded signal, and (iii) applies the stimulation signals to the recipient's auditory nerve via electrodes.
In another example cochlear implant, the functionality of the external speech processor unit and the implanted stimulator unit are combined to create a totally implantable cochlear implant (TICI). The TICI system can be either a monolithic system containing all of the components within a single implant housing or a collection of implant housings coupled together. In operation, detected sound is processed by a speech processor in the TICI system, and stimulation signals are delivered to the recipient via the electrodes without the need for a transcutaneous transmission of signals between an external speech processor unit and an implanted stimulator unit as in the traditional cochlear implant configuration described previously.
SUMMARY
A prosthesis implanted in a body is described. The prosthesis includes a rechargeable energy source, an implant coil that recharges the energy source, a stimulation decoder that provides an output to a hearing stimulator, and a single transformer. The single transformer electrically isolates the implant coil from the stimulation decoder and the hearing stimulator, and modifies an output of the rechargeable energy source for use by the stimulation decoder and the hearing stimulator.
A totally implantable prosthesis is also described. The totally implantable prosthesis includes a first circuit block containing a power source and a converter circuit, a second circuit block containing a stimulation decoder circuit for stimulating electrodes, and a single transformer. The single transformer provides electrical isolation between the first circuit block and the second circuit block. The single transformer also modifies the voltage from the power source to the second circuit block.
An active medical implant device (AIMD) is also described. The AIMD includes a main implant component. The main implant component includes a first circuit separated from a second circuit with a single transformer. The AIMD also includes an implant coil connected to the main implant component, a microphone system connected to the first circuit and a cochlear electrode connected to the second circuit. The transformer prevents AC and DC leakage from the cochlear electrode to the implant coil, the microphone system and the first circuit. The transformer also modifies a voltage from the first circuit to the second circuit. The main implant component, the implant coil, and the microphone reside inside a recipient's tissue after implantation.
These as well as other aspects and advantages will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it is understood that this summary is merely an example and is not intended to limit the scope of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
Presently preferred embodiments are described below in conjunction with the appended drawing figures, wherein like reference numerals refer to like elements in the various figures, and wherein:
FIG. 1 is a block diagram of a totally implantable cochlear implant (TICI) system, according to an example;
FIG. 2 is a block diagram of a main implantable component depicted in FIG. 1 , according to an example;
FIG. 3 is a circuit diagram of a Class D driver, according to an example; and
FIG. 4 is a circuit diagram of an inverted Class D Driver, according to an example.
DETAILED DESCRIPTION
FIG. 1 shows an example of a totally implantable cochlear implant (TICI) system 100 , which is totally implantable; that is, all of the components of the TICI system 100 are configured to be implanted under skin/tissue 116 of a recipient. Because all of the components of the TICI system 100 are implantable, the TICI system 100 operates, for at least a finite period of time, without the need of an external device.
An external device 118 can be used to charge an internal energy source and to supplement the performance of the TICI system 100 . The external device 118 may be a dedicated charger, a conventional cochlear implant sound processor, a remote control, or other device. In one example, the external device 118 is a Behind the Ear (BTE) headpiece coil, including an external microphone. Various types of energy transfer, such as infrared, electromagnetic, capacitive, and inductive transfer, may be used to transfer power and/or data from the external device 118 to the TICI system 100 .
The TICI system 100 includes a microphone 110 . The microphone 110 is configured to sense a sound signal 120 . The microphone 110 may also include one or more components to pre-process the microphone output. An electrical signal 122 representing the sound signal 120 detected by the microphone 110 is provided to the main implantable component 102 .
The TICI system 100 also includes an implant coil 112 . The implant coil 112 transcutaneously receives power and data signals from the external device 118 using one or more types of wireless transmission. For example, radio frequency (RF) links may be used to transmit power and data to the implant coil 112 . The implant coil 112 may also transmit data signals to the external device 118 . The implant coil 112 receives power in a recharging mode of operation.
The implant coil 112 is typically a wire antenna coil comprised of multiple turns of electrically insulated single-strand or multi-strand platinum or gold wire. The implant coil 112 may be produced using a silicone molding process, which can provide additional electrical insulation. Other coil designs may be used.
The TICI system 100 also includes a main implantable component 102 having a hermetically sealed, biocompatible housing. For example, the biocompatible housing can be constructed of a metal, metal alloy, ceramic, peek polymers, or other suitable material. The housing protects the recipient of the TICI system 100 both chemically and electrically.
The main implantable component 102 performs sound detection, speech processing, and stimulation functions. As seen in FIG. 1 , the main implantable component 102 includes a first circuit block 104 isolated from a second circuit block 106 via a single transformer 108 . If the housing material is magnetically (H-field) or electromagnetically (EM-field) transparent at the operating radio frequency, the implant coil 112 may also be located within the main implantable component 102 . For example, a housing material of ceramic or peek polymer may be suitable for containing the implant coil 112 within the main implantable component 102 .
The first circuit block 104 includes a rechargeable energy source. In one example, the rechargeable energy source is a battery, such as a lithium ion battery. The rechargeable energy source receives power from the implant coil 112 and stores the power. The output of the rechargeable energy source may be a DC voltage source or a DC current source. The power may then be distributed to the other components of the TICI system 100 as needed for operation.
The first circuit block 104 also includes a converter circuit. The converter circuit implements one or more speech processing and/or coding strategies to convert the pre-processed microphone output into data signals for use by a stimulation decoder circuit in the second circuit block 106 . Speech coding strategies include, but are not limited to, Continuous Interleaved Sampling (CIS), Spectral PEAK Extraction (SPEAK), Advanced Combination Encoders (ACE), and Fundamental Asynchronous Stimulus Timing (FAST).
The second circuit block 106 includes the stimulation decoder circuit that generates stimulation signals based on the coded signal received from the converter circuit in the first circuit block 104 and provides these signals to a hearing stimulator. The hearing stimulator delivers electrical stimulation signals to the cochlea of the recipient. In one example, the hearing stimulator is an electrode array 114 .
The electrode array 114 includes a plurality of intra-cochlear electrode pads or terminals 114 b configured to be positioned within the implant recipient's cochlea, and one or more extra-cochlear electrodes 114 a . The intra-cochlear electrode pads or terminals 114 b may include optical contacts and/or electrical contacts. The extra-cochlear electrode 114 a has an extra-cochlear electrode lead terminating in an electrode tip (sometimes referred to as a “ball” electrode) at the distal end of the electrode lead. The electrode tip is configured to be positioned beneath muscle tissue near the implant recipient's cochlea. The intra-cochlear electrode pads or terminals 114 b are typically configured to function as “active” (current source) electrodes, and the one or more extra-cochlear electrodes 114 a are typically configured to function as “reference” (current sink) electrodes.
The transformer 108 is a radio frequency (RF) transformer. The transformer 108 acts as an insulator between the electrodes 114 and other system elements residing in the tissue, such as the implantable microphone system 110 , the implant coil 112 , and components within the first circuit block 104 (e.g., the rechargeable energy source). In this role, the transformer 108 prevents electrical (e.g., AC and DC) leakage between the electrodes 114 and the other implantable system elements.
Stimulation of tissues and nerves using alternating electrical currents passing through tissue can cause problems for the recipient. For example, excess DC currents can cause electrolysis, redox reactions, and chemical reactions. The transformer 108 reduces electrical leakage, which minimizes negative side effects caused by electrical leakage.
The transformer 108 also acts as a voltage boost element providing a boost to the energy source output voltage. The transformer 108 modifies a compliance voltage as necessary to provide the correct stimulation current on each electrode 114 based upon an auditory stimulation algorithm or scheme that controls the timing and intensity of auditory stimulation pulses applied to the electrodes 114 . The compliance voltage is the voltage available at the electrode 114 that can force current to flow while still maintaining control of the working electrode voltage.
In this role, the transformer 108 is a part of a step-up DC/DC converter. The energy source output voltages are often lower than the electrode compliance voltage needed for correct operation of the electrode current sources. The compliance voltage of the electrode current sources depends on the impedance between the intra-cochlear electrodes 114 b and the extra-cochlear electrodes 114 a.
For example, if the impedance is 10 Kohms and the current source is 0.5 mA, the compliance voltage needs to be slightly greater than 5V (i.e., 10 Kohm*0.5 mA=5V). If the energy source is a lithium ion battery, the output voltage is approximately 3.7 volts. Thus, the transformer 108 boosts the lithium ion battery output of 3.7 volts to a value greater than 5 volts.
Using the transformer 108 in this manner provides tight coupling with minimal efficiency losses. By placing the energy source on the primary side of the transformer 108 and the stimulation decoder circuit on the secondary side of the transformer 108 , the transformer 108 provides step-up voltage control. Moreover, the transformer 108 prevents or reduces leakage between the electrode array 114 and other TICI system 100 components, such as the microphone 110 , the implant coil 112 , and components within the first circuit block 104 .
FIG. 2 is a block diagram of the main implantable component 102 , according to an example. As previously seen in FIG. 1 , the main implantable component 102 includes the first circuit block 104 isolated from the second circuit block 106 via the single transformer 108 . The implant coil 112 is connected to the primary side of the transformer 108 .
In this example, the first circuit block 104 includes a converter circuit 202 , a battery 204 , and additional power circuitry. The converter circuit 202 is an audio to radio frequency stimulation converter. The additional power circuitry includes battery protection 206 , a battery manager 208 , a rectifier 210 , a modulator 212 , a power control block 214 , and a driver 216 . The second circuit block 106 includes a capacitor 218 , a power and data extractor 220 , and a stimulation decoder 222 .
The driver 216 operates in Class-D or inverted Class-D (Class D −1 ) mode delivering power and stimulation data from the microphone 110 and implant battery 204 to the transformer 108 . FIG. 3 depicts a Class-D driver 300 , while FIG. 4 depicts an inverted Class-D driver 400 .
Operation Mode 1: Charging
During charging, a signal from the external device 118 delivers stimulation data to the stimulation decoder 222 , and power to the implant battery 204 and the stimulation decoder 222 . The power delivered to the battery 204 is used to recharge the battery 204 .
With the Class-D driver 300 , the N-MOSFETS of the Class-D (Class D1 and Class D2 driver) H-bridge driver are both closed, and parallel resonance is obtained by Cres_1 and Cres_2 (e.g., 5 MHz). The battery 204 can be charged using the rectifier 210 and the battery manager 208 . From the perspective of the stimulation decoder 222 , the transformer 108 is part of a parallel resonance tank formed by Cres_1 and Cres_2 in series and the inductance of the implant coil 112 . The implant coil 112 is scaled by the primary-secondary ratio of the transformer 108 .
With the inverted Class-D driver 400 , both MOSFETs are open and parallel resonance is obtained with Cres 218 (e.g., at 5 MHz). The battery 204 can be charged using the rectifier 210 and the battery manager 208 . From the perspective of the stimulation decoder 222 , the transformer 108 is part of a parallel resonance tank formed by Cres 218 and the inductance of the implant coil 112 . The implant coil 112 is scaled by the primary-secondary ratio of the transformer 108 .
Operation Mode 2: Normal Operations (Charged)
During normal operation when the battery is charged, the converter circuit 202 converts the microphone signal 122 to stimulation data. The stimulation data is then transferred to the modulator 212 . Preferably, the modulator 212 is an on-off keying (OOK) modulator. The modulator 212 may use other modulations schemes, such as Amplitude Shift Keying (ASK), Continuous Phase Frequency Shift Keying (CPFSK), Binary Phase Shift Keying (BPSK), and Quadrature Phase-Shift Keying (QPSK).
The power control block 214 controls power to the stimulation decoder 222 and the stimulation compliance voltage. The power control block 214 controls power and the stimulation compliance voltage by adjusting the duty cycle of RF frames and RF cycles. For example, the power control block 214 may use pulse width modulation (PWM) to adjust the duty cycle of the RF frames and RF cycles.
For the Class-D driver 300 , the impedance seen from the Class-D driver side is a series resonance circuit formed by Cres_1 and Cres_2 in series and the inductance of the implant coil 112 scaled by the primary-secondary ratio of the transformer 108 . The impedance seen from the stimulation decoder 222 is a parallel resonance tank formed by Cres_1 and Cres_2 in series and the inductance of the implant coil 112 scaled by the primary-secondary ratio of the RF transformer 108 .
The inverted Class-D driver 400 is powered through the transformer 108 center tap via the rfc coil (RF choke) forming a current source. From the perspective of the stimulation decoder 222 , the transformer 108 is part of a parallel resonance tank formed by Cres 218 and the inductance of the implant coil 112 . The implant coil 112 is scaled by the primary-secondary ratio of the transformer 108 .
As described, the single transformer 108 is used as both an AC/DC barrier and a step-up converter. More than one transformer would increase the volume needed for the implant housing. The transformer 108 is part of a resonant tank circuit built by the implant coil 112 and one or more capacitors.
Another benefit of this single transformer design is the ability to monitor the quality of the microphone 110 . During normal operating mode, the external device 118 can monitor the quality of the microphone 110 by using the implant coil 112 to transfer stimulation data from the microphone 110 to the external device 118 through the implant coil 112 once the Class-D driver 300 or the inverted Class-D driver 400 is activated. In this scenario, the external device 118 is connected to an external coil that is magnetically coupled to the implant coil 112 .
As yet another benefit of this single transformer design is the ability to use a conventional RF link when the rechargeable energy source is faulty or dead.
In an alternative design, the transformer 108 is used as an insulator between the implant coil 112 and the electrodes 114 , and other circuitry is used for the step-up converter function. For example, this additional circuitry can include a boost converter to increase voltage at the current sources of the electrodes 114 . The boost converter is an active circuit containing at least an inductor and two capacitors.
In another alternative design, the RF transformer 108 provides insulation between the implant coil 112 and the electrodes 114 , and a two-wire transformer provides insulation between the rechargeable energy source and the microphone 110 , and the electrodes 114 . While this alternative includes two transformers, a single RF transformer reduces the implant housing volume as compared to a design containing two RF transformers.
It is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is understood that the following claims including all equivalents are intended to define the scope of the invention. The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope of the following claims and equivalents thereto are claimed as the invention.
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A total implantable hearing aid system is described. The system includes a single transformer that acts as an insulator between simulation circuitry and associated electrodes, and other system elements residing in the tissue. These other system elements include an RF receiver coil, a microphone system, a battery, and a digital signal processor. The transformer also increases the battery output voltage to a level needed by the simulation circuitry with electrodes.
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RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application No. 60/092,076, filed Jul. 8, 1998, incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to electrotherapy methods and apparatus for delivering an electrical pulse to a patient's heart. More particularly the present invention relates to automatic external defibrillators (AEDs).
BACKGROUND OF THE INVENTION
Cardiac-arrest, exposure to high voltage power lines, and other trauma to the body can result in ventricular fibrillation. Ventricular fibrillation is the rapid and uncoordinated contraction of the myocardium of the heart. The use of external defibrillators to restore the heart beat to its normal pace through the application of an electrical shock is a well recognized and important tool in resuscitating patients. External defibrillation is typically used in emergency settings in which the patient is unconscious.
Automatic External Defibrillators (AEDs) are used by first responders such as police officers, fire fighters, and emergency medical technicians to resuscitate victims of sudden cardiac arrest. Studies have shown that the chances of successfully resuscitating a patient decrease approximately ten percent per minute following the onset of sudden cardiac arrest. Accordingly, a victim of sudden cardiac arrest will most likely not survive unless a trained rescuer responds in less than ten minutes after the cardiac arrest occurs and successfully defibrillates the heart.
Automatic External Defibrillators are designed to be very easy to use so that rescuers without extensive medical backgrounds can successfully resuscitate victims of sudden cardiac arrest. AEDs are currently being carried in emergency vehicles such as police cars, paramedic vehicles, and fire trucks. AEDs are also being widely deployed in areas where large numbers of people gather, such as at sports stadiums, gambling casinos, etc.
In one study, AEDs were used to assess cardiac rhythm in 18 patients with a mean age of 12.1±3.7 years. The cardiac rhythms were analyzed 67 times and included ventricular fibrillation (25), asystole/pulseless electrical activity (32), sinus bradycardia (6), and sinus tachycardia (4). The AEDs recognized all nonshockable rhythms accurately and advised no shock. Ventricular fibrillation was recognized accurately in 22 (88%) of 25 episodes and advised or administered a shock 22 times. Sensitivity and specificity for accurate rhythm analysis were 88% and 100%, respectively. One patient with a nonshockable rhythm survived, whereas 3 of 9 patients with ventricular fibrillation survived.
The data from this study furnish evidence that AEDs provide accurate rhythm detection and shock delivery to children and young adolescents. AED use is potentially as effective for children as it is for adults.
Accordingly, there is a need in the industry for AEDs adapted to deliver therapy to pediatric patients. Preferably, such adaptation should not require extensive modification to existing AEDs.
SUMMARY OF THE INVENTION
The device of the present invention substantially meets the aforementioned needs of the industry by readily adapting existing AEDs that are designed to deliver therapy to adult proportioned persons to smaller individuals. This adapting is accomplished without significant modification of the existing AEDs. In an embodiment, an energy reducer is electrically connected to at least two electrodes such that a portion of an adult-sized energy charge delivered to the electrodes for delivery to a patient is shunted from the electrodes. A lesser, scaled down energy charge appropriate to a pediatric patient is then delivered to the patient.
In another embodiment of this invention, coding of pediatric electrodes is provided to enable the AED to detect and identify a pediatric electrode. This is done by resistance or inductance coding, an imbedded memory chip or other comparable device. A further benefit of certain types of coding, such as inductance coding, is that it allows retrofitting of an AED to be converted to this type of pediatric mode having a scaled down energy charge with no hardware modifications by including a software change and utilization of the specialized pediatric electrodes. A further aspect of this invention is that the electrodes may be further distinguished to allow for a range of ages of body weights which would allow the AED to fine tune the algorithm and to scale the energy dosage to narrower pediatric weight/age ranges.
The present invention is an automatic external defibrillator (AED), including a device for scaling the stored energy communicated to the patient responsive to a known patient weight. The present invention is further an electrode system, for use with an automatic external defibrillator (AED), the AED includes a plurality of electrodes for making electrical contact with a skin surface of a patient. Each electrode of the plurality of electrodes is electrically connectable to a electrical connector for communicating a stored energy to a patient. The electrode system further includes a device for scaling the stored energy communicated to the patient responsive to a known patient weight. The present invention is additionally a method of defibrillating the heart of a human patient using an AED includes the steps of:
adherably placing at least two electrodes on the skin surface of the patient, the electrodes being spaced apart to define a desired energy path therebetween;
scaling the dischargeable defibrillating energy responsive to a known patient body weight; and
discharging defibrillating energy across the energy path, the discharge generating an energy vector, the vector being passable through the heart of the patient.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an automatic external defibrillator (AED) of the present invention;
FIG. 2 is schematic of the AED control system;
FIG. 3 is an exploded, perspective view of a defibrillation electrode of the present invention;
FIG. 4 is a plan view of a package pair of defibrillation electrodes;
FIG. 5 is an exploded view of a defibrillation electrode;
FIG. 6 is a plan view of the defibrillation system of the present invention;
FIG. 7 is a block diagram of an embodiment of the defibrillation system;
FIG. 8 is a block diagram of a second embodiment of the defibrillation system; and
FIG. 9 is a schematic circuit diagram of an embodiment of the defibrillation system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The AED of the present invention is shown generally at 10 in FIG. 1. AED 10 includes case 12 with carrying handle 14 and battery pack 16, which is removably disposed within a battery compartment (not shown) in case 12. Battery pack 16 functions as an energy source for AED 10. Visual maintenance indicator 20 and data access door 22 are located on the outside of case 12 to facilitate access by the operator. Case 12 also includes panel 24 and has electrode compartment 26 defined in a top portion thereof. Panel 24 includes illuminable resume/rescue switch 18 and diagnostic display panel 25 with "electrodes" indicator light 28. Panel 24 and electrode compartment 26 are enclosed by selectively closeable lid 27.
Electrode compartment 26 contains electrode connector 30 and electrode pouch 40, which, in the prior art, hermetically encloses an electrode set 50 comprising a pair of electrodes 50A, 50B. Electrodes 50A, 50B are removably connected to electrode connector 30 by leads 52. Connector 30 is typically configured with two connectors, one connector for connecting to a first electrode 50A and the second connector for connecting to a second electrode 50B. Electrodes 50A, 50B are adhered to a patient prior to a rescue intervention procedure with AED 10.
Exemplary electrical system 70 of AED 10 is depicted in the schematic diagram of FIG. 2. The overall operation of AED 10 is controlled by digital microprocessor-based control system 72. Control system 72, in turn, includes processor 74, program memory 76, data memory 77, event memory 78, and real time clock 79. Processor 74 is interfaced to program memory 76, data memory 77, event memory 78 and real time clock 79. The operating program executed by processor 74 is stored in program memory 76. Data memory 77 is used by processor 74 as a scratch pad memory during the execution of an operating program of AED 10.
Electrical power is provided by battery 80 disposed in battery pack 16. In a preferred embodiment, battery 80 is a lithium-sulphur dioxide battery. Battery pack 16 may be removably positioned within the battery compartment of case 12. Battery 80 may include a plurality of interconnected, individual battery cells as desired. Battery 80 is connected to power generation circuit 84. "Battery Status" indicator light 38 (see also FIG. 1) indicates the charge status of battery 80 and prompts the operator to replace battery 80 when necessary.
During normal operation, power generation circuit 84 generates regulated ±5V, and 12V (actually about 5.4V and about 11.6V) supplies with electrical power provided by battery 80. A 3.3V supply is generally used to power real time clock 79 and lid switch 90. The 3.3V supply also powers watch dog timer 92 when lid 27 is in a closed position (e.g., when AED 10 is in a standby mode). The ±5V output of power generation circuit 84 functions as a back-up battery to power components of electrical system 70 during the execution of self-tests (described below). The ±5V output of circuit 84 also activates maintenance indicators and alarms (also described below). Although not separately shown, power generation circuit 84 includes voltage level sensing circuits which are coupled to processor 74. These voltage level sensing circuits provide low battery level signals to processor 74 for display on "Battery Status" indicator light 38.
Power generation circuit 84 is also connected to power control circuit 88 and processor 74. Power control circuit 88 is connected to lid switch 90, watch dog timer 92, real time clock 79 and processor 74. Lid switch 90 is a magnetic reed relay switch in one embodiment or may be a Hall effect sensor. Lid switch 90 provides signals to processor 74 indicating whether lid 27 is open or closed. Serial connector port 23 is coupled to processor 74 for two-way serial data transfer using an RS-232 protocol.
Resume/rescue switch 18, "Maintenance" indicator 20, "Battery Status" indicator light 38, "Electrodes" indicator light 28, and "Service" indicator light 42 of diagnostic display panel 36, voice circuit 94 and piezoelectric audible alarm 96 are also connected to processor 74. Voice circuit 94 is connected to speaker 34. In response to voice prompt control signals from processor 74, voice circuit 94 and speaker 34 generate audible voice prompts provided to the operator.
High voltage generation circuit 86 is also connected to and controlled by processor 74. High voltage generation circuits such as circuit 86 are known and disclosed, for example, in the commonly assigned Persson et al. U.S. Pat. No. 5,405,361, which is hereby incorporated by reference. In response to charge control signals provided by processor 74, high voltage generation circuit 86 is operated in a charge mode. During the charge mode of operation, one set of semiconductor switches (not separately shown) causes a plurality of capacitors (not separately shown) to be charged in parallel to a potential of about 400V. Each capacitor is charged by power supplied by power generation circuit 84. Once charged, and in response to discharge control signals from processor 74, high voltage generation circuit 86 is operated in a discharge mode. During discharge, the capacitors are discharged in series by another set of semiconductor switches (not separately shown) to produce high voltage defibrillation pulses. The defibrillation pulses are applied to the patient by electrodes 50A, 50B of electrode set 50, via electrode connector 32. Electrode connector 32 is connected to high voltage generation circuit 86. Under certain circumstances (described below), processor 74 causes high voltage generation circuit 86 to be discharged through internal resistive load 98 rather than connector 32 to electrode set 50.
Impedance measuring circuit 100 is connected to electrode connector 32 and real time clock 79. Impedance measuring circuit 100 is also interfaced to processor 74 through analog-to-digital (A/D) converter 102. Impedance measuring circuit 100 receives a clock signal with a predetermined magnitude from clock 79 and applies the signal to electrodes 50A, 50B through connector 32. The magnitude of the clock signal received back from electrodes 50A, 50B through connector 32 is monitored by impedance measuring circuit 100. An impedance signal representative of the impedance present across electrode connector 32 is then generated by circuit 100 as a function of the ratio of the magnitudes of the applied and received clock signals (i.e., a measure of the attenuation of the applied signal). For example, if the conductive adhesive on electrodes 50A, 50B is too dry, if electrodes 50A, 50B are not properly connected to connector 32, or if electrodes 50A, 50B are not properly positioned on the patient, a relatively high resistance (e.g., greater than about 200 ohms) will be present across connector 32. The resistance across connector 32 will be between about 25 and 175 ohms when fresh electrodes 50A, 50B are properly positioned on the patient with good electrical contacts. The signal representative of the impedance measured by circuit 100 is digitized by A/D converter 102, then relayed to processor 74.
AED 10 also includes data recorder 103 and electrocardiogram (ECG) filter and amplifier 104. Data recorder 103 is interfaced to processor 74. Data recorder 103 is positioned internally within AED 10 adjacent to data card slot 24 (see also FIG. 1), so as to be ready to accept data (rescue information) card (not shown). ECG filter and amplifier 104 is connected between electrode connector 32 and A/D converter 102. The ECG or cardiac rhythm of the patient is sensed by electrode set 50 when electrodes 50A, 50B are placed on the patient and processed by ECG filter and amplifier 104 in a conventional manner, then digitized by A/D converter 102 before being relayed to processor 74.
The rescue mode of operation of AED 10 is initiated when an operator opens lid 27 to access electrodes 50A, 50B. An opened lid 27 is detected by lid switch 90. Lid switch 90 functions as an on/off switch for AED 10. In response to lid switch 90 being activated when lid 21 is opened, power control circuit 88 activates power generation circuit 84 and initiates the rescue mode operation of processor 74. Processor 74 then begins its rescue mode operation by: (1) switching maintenance indicator 20 to a maintenance required state (a red visual display in one embodiment); (2) flashing the "rescue" light associated with resume/rescue switch 18 and the indicator lights on diagnostic display panel 36; and (3) performing a lid opened self-test.
During the lid opened self-test, checks performed by processor 74 include: (1) the charge state of battery 80; (2) the interconnection and operability of electrodes 50A, 50B (if the electrode test enabled); (3) the state of event memory 78; (4) the functionality of real time clock 79; and (5) the functionality of A/D converter 102. The charge state of battery 80 is checked by monitoring the voltage level signals provided by power generation circuit 84 and comparing these voltage level signals to predetermined nominal values. If battery 80 is determined to have a low charge, the "battery status" indicator 38 on diagnostic display panel 36 will indicate the sensed status. If the electrode self-test is conducted, the interconnection and operability of electrodes 50A, 50B are checked by monitoring the impedance signals provided by impedance measuring circuit 100. If electrodes 50A, 50B are missing or unplugged from connector 32, if electrodes 50A, 50B are damaged, or if the conductive adhesive on electrodes 50A, 50B is too dry, processor 74 will illuminate "Electrodes" indicator light 40 on diagnostic display panel 36.
Also, during the lid opened self-test, processor 74 accesses event memory 78 to determine whether data from a previous rescue operation are still stored therein. If data from a previous rescue are still present, processor 74 causes the "resume" indicator associated with resume/rescue switch 18 on diagnostic panel 36 to be illuminated and initiates the generation of a "Clear Memory" voice prompt. If resume/rescue switch 18 is pressed by the operator following the activation of these indicators, processor 74 clears event memory 78 and proceeds with its rescue mode of operation. The functionality of real time clock 79 and A/D converter 102 are checked by monitoring the outputs of these circuit elements for expected signals. Diagnostic display panel "Service" light 42 is illuminated by processor 74 if faults are identified in real time clock 79 or in A/D converter 102.
If the lid opened self-test is successfully completed, processor 74 switches maintenance indicator 20 to an operational state and initiates the rescue mode of operation of AED 10. In the rescue mode of operation voice circuit 94 generates audible voice prompts through speaker 34 to guide the operator through the operations of AED 10 and, if necessary, delivery of a defibrillation pulse to the patient. AED 10 determines its rescue mode steps of operation by monitoring the impedance across electrode connector 32 and the patient's cardiac rhythm.
Closing lid 27 after rescue mode operation activates processor 74 to initiate and perform a lid closed self-test. During the lid closed self-test, processor 74 performs a comprehensive check of the status and functionality of AED 10 including: (1) the state of event memory 78; (2) the functionality of real time clock 79; (3) the functionality of A/D converter 102; (4) the functionality of program memory 76, data memory 77, and event memory 78; (5) the charge state of battery 80; and (6) the interconnection and operability of electrodes 50A, 50B (if enabled to do so). The state of event memory 78, the state of battery 80, the interconnection and operability of electrodes 50A, 50B, and the functionality of real time clock 79 and A/D converter 102 are checked in a manner identical to that described above with reference to the lid opened self-test.
Conventional memory test routines are also implemented to check the functionality of program memory 76, data memory 77 and event memory 78. Maintenance indicator 20 is switched to its maintenance required state by processor 74 if faults are identified during the lid closed self-test. No audible alarms are actuated if faults are identified in the charge state of battery 80 or the interconnection or functionality of electrodes 50A, 50B during the lid closed self-test.
A daily self-test is also initiated and performed by processor 74 at a predetermined time each day (i.e., every twenty-four hours). During the daily self-test, processor 74 performs all the component check operations described above that are performed during the lid opened and lid closed self-tests. In addition to illuminating the appropriate lights on diagnostic display panel 36, processor 74 leaves maintenance indicator 20 in a maintenance required state if faults are identified during the daily self-test.
Processor 74 also initiates and performs a weekly self-test at a predetermined time one day each week. During the weekly self-test, processor 74 performs all the component check operations described above that are performed during the daily self-test. In addition, processor 74 causes high voltage generation circuit 86 to sequentially operate in its charge and discharge modes, the charge being directed to internal resistive load 98. When high voltage generation circuit 86 is operating in a charge mode, processor 74 monitors the time required to charge the circuit's capacitors and the capacitor voltage. A fault is identified if either time is outside nominal conditions. Maintenance indicator 20 and alarm 96 are actuated in the manner described above if any faults are identified during the weekly self-test. All performed test and patient data may be recorded in event memory 78.
Watch dog timer 92 is set to time watch dog time-out periods of about thirty hours (i.e., a period greater than the twenty-four hour periods between daily self-tests). Watch dog timer 92 is reset by processor 74 at the beginning of each daily self-test and each time lid 27 is opened. In the event control system 70 malfunctions and watch dog timer 92 times out, internal hardware switches maintenance indicator 20 to the maintenance required state and actuates alarm 96 to alert the operator to the fact that AED 10 requires maintenance.
AED 10 facilitates archival storage of rescue information. Data representative of the operation of AED 10 and patient data may be stored in event memory 78 during rescue mode operation. However, if a data card (not shown) is inserted into card slot 24 before the beginning of a rescue attempt, the rescue information is automatically recorded by data recorder 103 onto the data card, thereby also facilitating archival storage of rescue information. Stored data representative of the operation of AED 10 may include the real time of the occurrence of each of the following events: (1) the placement of electrodes 50A, 50B on the patient, (2) the initiation of the cardiac rhythm analysis voice prompt, (3) the initiation of the charging voice prompt, (4) the completion of the charge mode operation of high voltage generation circuit 86, and (5) the actuation of the resume/rescue switch 18 in the rescue mode. The actual time base of the patient's cardiac rhythm (ECG information) may also be stored. Data representative of the patient may include the monitored cardiac rhythm, key events detected during the rescue operation, and sound occurring within the vicinity of AED 10.
Following a rescue, the stored data may be retrieved from event memory 78 through the use of computer (PC) 105 interfaced to serial connector port 22. Real time clock 79 can also be set through the use of PC 105 interfaced to port 22. If the rescue data were stored on the data card and the data card remains in slot 24, the date may also be retrieved through the use of PC 105 interfaced to serial connector port 22. Alternatively, data card 29 may be removed from slot 24 and inserted into an appropriate card reader (not shown), directly connected to PC 105, such as a PCMCIA type I card reader.
Upon the completion of each lid opened, lid closed, daily and weekly self-test, processor 74 causes a record of the self-test to be stored in event memory 78. Each stored record includes data representative of the date and time of the test and the results of the test. The test results are recorded in the form of a code or other description indicating whether all the functions, components and component status states passed the test, or indicating the nature of any identified faults. In one embodiment, only the records of the twenty most recently performed tests are stored in memory 78. The stored self-test records may be retrieved from memory 78 through PC 105 interfaced to serial connector port 22. Each self-test is powered by the battery 80. The battery 80 may also be coupled to real time clock 79 to continuously provide power thereto.
Selected operating parameters determine how AED 10 administers defibrillation shocks (or pulses), performs self-tests, and stores rescue data. These selected parameters may be modified by an exemplary software-enabled protocol as described below. As indicated in Table 1, these parameters may include "Second Shock Energy", "Maximum Shocks Per Rescue", "Same Energy After Conversion", "Daylight Savings", "Electrode Test", and "External Memory Storage".
TABLE 1______________________________________Function Default Selectable Options______________________________________Second Shock Energy (J) 300J 200JMaximum Shocks Per Rescue 255 6 to 255Same Energy After Conversion Enabled DisabledDaylight Savings Enabled DisabledElectrode Test Enabled DisabledExternal Memory Storage Long Rescue Voice Record______________________________________
In a rescue intervention, a series of increasing energy level shocks may typically be delivered to a patient. The AED 10 provides for varying the energy of the second shock. The Second Shock Energy parameter determines the energy in Joules (j) delivered in the second defibrillation pulse to a patient by AED 10. The default value for the Second Shock Energy parameter is 300J; however, a value of 200J may be selected.
The Maximum Shocks Per Rescue parameter determines the number of defibrillation pulses delivered by AED 10 during a rescue. The default value for the Maximum Shocks Per Rescue parameter is 255; but, any number of defibrillation pulses between 6 and 255 inclusive may be selected.
The Same Energy After Conversion parameter determines whether the same energy as the previous defibrillation pulse will be delivered when the patient assumes (or converts to) a normal sinus heart rhythm, but then reverts back to a shockable cardiac rhythm. The default status for the Same Energy After Conversion parameter is enabled, e.g., the same energy as the previous pulse will be delivered. This parameter may be disabled by the present protocol as described below.
Referring to FIGS. 3-5, electrodes 50A, 50B include flexible, adhesive coated backing layer 53 (preferably a polymeric foam), and patient engaging layer 54. Patient engaging layer 54 is preferably a hydrogel material which has adhesive properties, and which is electrically conductive. Hydrogel adhesive of this type is commercially available from LecTec Corporation (Minnetonka, Minn.) and Tyco International Ltd. (Hamilton, Bermuda). Current dispersing flexible conductive portion 56 is preferably located between backing layer 53 and patient-engaging hydrogel layer 54. Conductive portion 56, as shown, need not be the same size as backing layer 53 and is preferably a homogeneous, solid, thinly deposited metallic substance, or a conductive ink.
An adhesive coated border 57 is formed by a portion of adhesive coated backing layer 53. This adhesive coated border extends about conductive portion 56 and patient engaging hydrogel layer 54. Insulated lead wire 52 is terminated with a wire terminal 70 at a first end and a connector 32 at a second end. Wire terminal 70 is electrically connected to conductive portion 56 via conductive rivet 74 and washer 72. Conductive rivet 74 is covered on a first side with insulating disk 76. Conductive rivet 74, washer 72, and wire terminal 70 are all covered on a second side with insulating pad 78. Electrode connector 32 is designed to make electrical connection with AED connector 30 (see FIG. 1).
Further examples of electrode pad construction for use with AED 10 are described and shown in U.S. Pat. Nos. 5,697,955, 5,579,919, and 5,402,884, all hereby incorporated by reference.
The inventive pediatric electrode set 300 of the present invention is depicted in FIG. 6. Exemplary electrode set 300 includes an electrical connector 320 which mates with AED connector 30 of AED 10.
Electrode set 300 includes a first electrode 50A and a second electrode 50B, substantially as described above with reference to FIGS. 3-5. Electrode set 300 could include more than two electrodes, as desired. Electrodes 50A, 50B include backing layer 53, patient engaging hydrogel layer 54, conductive portion 56, and insulating pad 78. Electrodes 50A, 50B are electrical connected to an energy reducer 304 with lead wires 306A, 306B. Energy reducer 304 is connected to connector 32 with wires 308A, 308B.
FIG. 7 is a block diagram of the pediatric defibrillation set 300 of FIG. 6. Electrodes 50A, 50B are electrically connected to energy reducer 304 by lead wires 306A, 306D. Energy reducer 304 is electrically connected to connector 32 by connecting wires 308A, 308B. Connector 32 is releasably mated with connector 30 of AED 10.
FIG. 8 is a block diagram illustrating a second embodiment of the pediatric defibrillation set 300. Electrodes 50A, 50B are electrically connected to connector 58. Connector 50 is releasably mated with connector 310 of energy reducer 304. Energy reducer 304 is electrically connected to connector 32 by connecting wires 308A, 308B. Connector 32 is releasably mated with connector 30 of AED 10. Those skilled in the art will readily recognize that a number of embodiments are possible for energy reducer 304. These embodiments include networks of electronic components including but not limited to resistors, capacitors, and gas tube surge arrestors.
FIG. 9 is a schematic circuit diagram of one embodiment of the pediatric defibrillation set 300. In this embodiment, energy reducer 304 includes a shunt resistor 320. Resistor 322 represents the electrical impedance between electrodes 50A, 50B when the electrodes 50A, 50B are adhered to the patient. The electrical impedance 322 depicted is the impedance across the patient's chest.
Preferably, the shunt resistor 320 is built into the connecting wires 308A, 308B so that the operator selects a pair of electrodes according to the operator's estimation of the patient's weight. Preferably, four sets of electrodes 50A, 50B are supplied with the AED 10. The electrodes may be color-coded or otherwise identified to correspond to a given patient body weight. The first set of electrodes is adult electrodes 50A, 50B as described with reference to FIGS. 3-5 above, which have no shunt resistor 320 whatsoever. A further three pairs of pediatric electrode systems 300 are supplied with the AED 10. There is preferably one electrode pair for patients who are 0 to 10 kilograms. There is another set of electrodes 50A, 50B, having different identification, that is for patients who are 10 to 20 kilograms in weight. And, there is a pair of electrodes 50A, 50B for patients who are 20 to 40 kilograms. Each of those pediatric electrodes 50A, 50B of pediatric electrode set 300 has a shunt 304 built into the wires 308A, 308B to reduce the energy to the electrodes 50A, 50B.
The first electrode set 300, for the 0 to 10 kilograms body weight, should be about 20 joules delivered to the patient. However, the defibrillators 10 typically escalate the energy level of successive shocks, as indicated above. The adult shocks are typically 200 joules, 300 joules, 360 joules for successive shocks. With the pediatric electrode set 300, the shunt 304 reduces the energy to the electrodes 50A, 50B to about 10 joules, 20 joules, 40 joules. With electrode set 300 adapted for 10 to 20 kilogram patients the reduction would be to about 60 joules, 80 joules, 100 joules. And, with electrode set 300 adapted for patients who are 20 to 40 kilograms the reduction is to around 120 joules, 140 joules and 160 joules.
In a further embodiment as depicted in FIG. 10, an exemplary pediatric electrode set 400 may include special pediatric electrodes 402, 404, which may be a specially reduced sized to better fit a pediatric patient. A number of different sets of electrodes, 402, 404 may be provided, each different set being indicated for use with patients of differing weight ranges. Electrode set 400 may include more than two electrodes, as desired. See electrode 404a, which may be applied to the anterior region of the patient's chest. Electrode set 400 has means of coding AED 10 that can be read by the processor 74 of the AED 10 when the electrode set 400 is plugged into the connector 30 of the AED 10. When the processor 74 detects the special pediatric electrode set 400, the processor 74 changes certain parameters of the detection algorithm to make it more suited to detecting heart rhythms of a pediatric patient by means of the electrodes 402, 404. Further, the processor 74 may select a different set of voice prompts for delivery to speaker 34 that are specifically suited to a pediatric patient for prompting an operator in the delivery of therapy to the pediatric patient. Additionally, the processor 74 may select a pediatric dosage of electricity for the therapeutic shock that is reduced as compared to the above adult dosage.
A further aspect of this invention are means to enable the processor 74 of the AED 10 to detect and identify pediatric electrodes 402, 404. This is alternatively done by resistance or inductance coding, or an imbedded memory chip 408 in the electrodes 402, 404 or other suitable method. In resistance coding, an amount of resistance 405 that is unique to the pediatric set 400 is added to a wire connector 406a, 406b. Resistance 405 may be changed for different electrodes 402, 404 for use with different weight patients. The inductance of the electrode circuit will change with a reduced size of the pediatric electrodes 402, 404 as compared to the larger adult electrodes 50A, 50B. This results from the change in current in the electrode circuit. This change in inductance is detectable by the processor 74 of the AED 10. The inductance will be different for the various electrodes 402, 404 to be used with varying weight pediatric patents. A further benefit of certain types of coding such as inductance coding, is that it allows retrofitting of an existing AED 10 to be converted to this type of pediatric mode with no hardware modifications to the AED 10 by including a software change effected in processor 74 to recognize the coding and to effect the aforementioned changes and by utilization of the specialized pediatric electrodes 402, 404.
Another further aspect of this invention is that the electrodes are further distinguished by the coding to allow for a range of ages of body weights which would allow the processor 74 of AED 10 to fine tune the algorithm and energy dosage to a narrower weight/age range. For example, when an electrode 402 coded to 10-20 lbs. is utilized, AED 10 selects one set of detection and energy specifications for 10-20 lbs., another electrode 402 coded 20-40 lbs. causes AED 10 to select a different set of detection and energy specifications suitable for 20-40 lbs. patients, and still another electrode 402 causes AED 10 to select parameters for 40-60 lbs. patients.
The operation of AED 10 is generally described briefly below. A rescue mode of AED 10 is initiated when lid 27 is opened to access electrodes package 40 containing electrodes 50A, 50B. The opening of lid 27 is detected by lid open on/off switch 90 of the AED 10 to effectively turn on the device. AED 10 then quickly runs a short test routine as indicated above. After electrodes 50A, 50B have been placed on the patient, AED 10 senses patient specific parameters, such as impedance, voltage, current, charge, or other measurable parameters of the patient specifically related to cardiac condition.
If a shockable condition is detected through electrodes 50A, 50B, a plurality of capacitors inside of AED 10 are charged, as indicated above. Based upon the pediatric patient specific parameters sensed, the duration and other characteristics of a discharge waveform are then calculated suitable to a pediatric patient. The energy stored in AED 10 is then discharged to the pediatric patient through electrodes 50A, 50B.
For a more detailed description of the physical structure of AED 10 or the process involved in sensing, charging, shocking, and testing, reference should be made U.S. Pat. No. 5,645,571 entitled AUTOMATED EXTERNAL DEFIBRILLATOR WITH LID ACTIVATED SELF-TEST SYSTEM, which is herein incorporated by reference.
For operation of AED 10 with respect to the present invention, when a first responder arrives at an emergency scene, the responder evaluates the patient's condition and the first responder looks at the patient to estimate the patient's body weight. If the patient is a pediatric patient (less than about 80 lbs.), the responder then picks the appropriate electrode set 300, 400 for a pediatric patient. If the responder determines that the patient is unconscious, not breathing, and has no pulse, the patient is a candidate for therapy delivered by the AED. Connector 32 is releasably mated with connector 30 of AED 10. Electrodes 50A, 50B are then applied to the patient's chest spaced apart to define an electrical path through the patient.
The AED 10 analyzes the rhythm of the patient's heart, preferably using detection parameters suited particularly to a pediatric patient having a selected body weight range, and determines if the patient is in ventricular fibrillation (VF) or another condition which can be treated with a rescue shock. If a shock is advised, the AED 10 will communicate this to the rescuer using voice prompts. The rescuer then pushes rescue button 18 to deliver a shock. A shock having energy appropriate to the specific selected pediatric patient body weight range is delivered to electrodes 50A, 50B.
In the instance when the electrode set 300 is utilized, a normal adult energy level is delivered by AED 10. When the shock is delivered, the energy reducer 304 reduces the energy delivered by AED 10 to the electrodes 50A, 50B to a level appropriate for a pediatric patient. In the embodiment shown in FIG. 8, a portion of the shock energy is delivered to shunt resistor 320, the remainder of the shock energy is delivered to the patient (represented by resistor 322 in FIG. 9). An energy vector is defined preferably centrally through the patient's heart, in order to best effect the defibrillation desired.
In the instance when the electrode set 400 is utilized (FIG. 10), the algorithm of the processor 74 of AED 10 detects the presence of the specific coding associated with the electrode set 400. The voice prompts to the first responder are altered appropriate to the relatively small size of the pediatric patient. Further, the heart rhythm detection parameters are altered appropriate to the relatively small size of the pediatric patient and the shock delivered to the patient is reduced appropriate to the relatively small size of the patient, as indicated by the unique coding of the electrode set 400 for a particular range of body weights.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit or scope of the present invention.
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An automatic external defibrillator (AED) includes a device for scaling the stored energy communicated to the patient responsive to a known patient weight. An electrode set, for use with an automatic external defibrillator (AED), the AED includes a plurality of electrodes for making electrical contact with a skin surface of a patient. Each electrode of the plurality of electrodes is electrically connectable to a electrical connector for communicating a stored energy to a patient. The electrodes system further includes a device for scaling the stored energy communicated to the patient responsive to a known patient weight. A method of defibrillating the heart of a human patient using an AED includes the steps of:
adherably placing at least two electrodes on the skin surface of the patient, the electrodes being spaced apart to define a desired energy path therebetween;
scaling the dischargeable defibrillating energy responsive to a known patient body weight; and
discharging defibrillating energy across the energy path, the discharge generating an energy vector, the vector being passable through the heart of the patient.
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RELATED APPLICATION
[0001] This application is a continuation application of application Ser. No. 13/155,112, Attorney Docket Number SCTY-P58-2NUS, entitled “TRANSPARENT CONDUCTING OXIDE FOR PHOTOVOLTAIC DEVICES,” by inventors Jianming Fu, Zheng Xu, Jiunn Benjamin Heng, and Chentao Yu, filed 7 Jun. 2011, which claims the benefit of U.S. Provisional Application No. 61/353,119, Attorney Docket Number SSP10-1009PSP, entitled “Transparent Conducting Oxide for Photovoltaic Devices,” by inventors Jianming Fu, Zheng Xu, Jiunn Benjamin Heng, and Chentao Yu, filed 9 Jun. 2010.
BACKGROUND
[0002] 1. Field
[0003] This disclosure is generally related to solar cells. More specifically, this disclosure is related to a solar cell that includes a high work function transparent conducting oxide (TCO) layer.
[0004] 2. Related Art
[0005] The negative environmental impact caused by the use of fossil fuels and their rising cost have resulted in a dire need for cleaner, cheaper alternative energy sources. Among different forms of alternative energy sources, solar power has been favored for its cleanness and wide availability.
[0006] A solar cell converts light into electricity using the photoelectric effect. There are several basic solar cell structures, including a single p-n junction, p-i-n/n-i-p, and multi-junction. A typical single p-n junction structure includes a p-type doped layer and an n-type doped layer. Solar cells with a single p-n junction can be homojunction solar cells or heterojunction solar cells. If both the p-doped and n-doped layers are made of similar materials (materials with equal band gaps), the solar cell is called a homojunction solar cell. In contrast, a heterojunction solar cell includes at least two layers of materials of different bandgaps. A p-i-n/n-i-p structure includes a p-type doped layer, an n-type doped layer, and an intrinsic (undoped) semiconductor layer (the i-layer) sandwiched between the p-layer and the n-layer. A multi-junction structure includes multiple single-junction structures of different bandgaps stacked on top of one another.
[0007] In a solar cell, light is absorbed near the p-n junction generating carriers. The carriers diffuse into the p-n junction and are separated by the built-in electric field, thus producing an electrical current across the device and external circuitry. An important metric in determining a solar cell's quality is its energy-conversion efficiency, which is defined as the ratio between power converted (from absorbed light to electrical energy) and power collected when the solar cell is connected to an electrical circuit.
[0008] For homojunction solar cells, minority-carrier recombination at the cell surface due to the existence of dangling bonds can significantly reduce the solar cell efficiency; thus, a good surface passivation process is needed. In addition, the relatively thick, heavily doped emitter layer, which is formed by dopant diffusion, can drastically reduce the absorption of short wavelength light. Comparatively, heterojunction solar cells, such as Si heterojunction (SHJ) solar cells, are advantageous. FIG. 1 presents a diagram illustrating an exemplary SHJ solar cell (prior art). SHJ solar cell 100 includes front finger electrode 102 , a heavily doped amorphous-silicon (a-Si) emitter layer 104 , an intrinsic a-Si layer 106 , a crystalline-Si substrate 108 , and an Al back-side electrode 110 . Arrows in FIG. 1 indicate incident sunlight. Because there is an inherent bandgap offset between a-Si layer 106 and crystalline-Si (c-Si) layer 108 , a-Si layer 106 can be used to reduce the surface recombination velocity by creating a barrier for minority carriers. The a-Si layer 106 also passivates the surface of crystalline-Si layer 108 by repairing the existing Si dangling bonds. Moreover, the thickness of heavily doped a-Si emitter layer 104 can be much thinner compared to that of a homojunction solar cell. Thus, SHJ solar cells can provide a higher efficiency with higher open-circuit voltage (V oc ) and larger short-circuit current (J sc ).
[0009] When fabricating solar cells, a layer of transparent conducting oxide (TCO) is often deposited on the a-Si emitter layer to form an ohmic-contact. However, due to the large band gap and high work function of the heavily doped p + amorphous Si emitter layer, it is hard to form low-resistance ohmic contact between a conventional TCO material, such as indium tin oxide (ITO), and the heavily doped a-Si emitter.
SUMMARY
[0010] One embodiment of the present invention provides a solar cell. The solar cell includes a Si base layer, a passivation layer situated on a first side of the Si base layer, a layer of heavily doped p-type amorphous semiconductor situated on the passivation layer, a first transparent-conducting-oxide (TCO) layer situated on the heavily doped amorphous semiconductor layer, and a first electrode situated on the first TCO layer. The first TCO layer comprises at least one of: GaInO, GaInSnO, ZnInO, and ZnInSnO.
[0011] In a variation on the embodiment, the first side of the Si base layer is facing the incident sunlight.
[0012] In a variation on the embodiment, the solar cell includes a second electrode situated on a second side of the Si base layer, and the second side is opposite to the first side.
[0013] In a further variation, the second side of the Si base layer is facing the incident sunlight, and the second electrode includes a second TCO layer and a metal grid comprising Cu and/or Ni.
[0014] In a variation on the embodiment, the Si base layer includes a crystalline-Si (c-Si) substrate.
[0015] In a variation on the embodiment, the Si base layer includes an epitaxially formed crystalline-Si (c-Si) thin film.
[0016] In a variation on the embodiment, the passivation layer includes at least one of: undoped a-Si and SiO x .
[0017] In a variation on the embodiment, the heavily doped p-type amorphous semiconductor layer has a doping concentration between 1×10 17 /cm 3 and 5×10 20 /cm 3 .
[0018] In a variation on this embodiment, the first TCO layer has a work function between 4.9 eV and 6.1 eV.
[0019] In a variation on the embodiment, the solar cell further comprises a third TCO layer situated on the first TCO layer, and the third TCO layer has a lower resistivity than the first TCO layer.
[0020] In a further variation, the third TCO layer includes at least one of: indium tin oxide (ITO), tin-oxide (SnOx), aluminum doped zinc-oxide (ZnO:Al), and Ga doped zinc-oxide (ZnO:Ga).
[0021] In a variation on the embodiment, the first electrode comprises at least one of: Ag, Cu, and Ni.
[0022] In a variation on the embodiment, the p-type amorphous semiconductor comprises amorphous Si or amorphous Si containing carbon.
BRIEF DESCRIPTION OF THE FIGURES
[0023] FIG. 1 presents a diagram illustrating an exemplary Si heterojunction (SHJ) solar cell (prior art).
[0024] FIG. 2 presents a diagram illustrating the band diagrams at the interface between high/medium/low work function TCO material and p-type amorphous Si.
[0025] FIG. 3 presents a diagram illustrating the process of fabricating a solar cell in accordance with an embodiment of the present invention.
[0026] FIG. 4 presents a diagram illustrating an exemplary solar cell in accordance with an embodiment of the present invention.
[0027] FIG. 5 presents a diagram illustrating an exemplary solar cell in accordance with an embodiment of the present invention
[0028] In the figures, like reference numerals refer to the same figure elements.
DETAILED DESCRIPTION
[0029] The following description is presented to enable any person skilled in the art to make and use the embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
Overview
[0030] Embodiments of the present invention provide an SHJ solar cell that includes a layer of novel TCO material with high work function. The relatively high work function, up to 6.1 eV, of the TCO material ensures lower contact resistance and higher V oc .
[0031] TCO film has been widely used in solar cells to form ohmic contact with the emitter layer. An SHJ solar cell can be formed by depositing a-Si layers on a c-Si substrate. Note that the a-Si layers include a layer of doped a-Si in order to form a junction with the c-Si substrate or to ensure good electrical contact with a subsequently formed electrode. A TCO layer is often deposited on the doped a-Si layer to form an ohmic contact. However, due to the large band gap and high work function of the p-type doped a-Si layer, it is difficult to find a TCO material with work function that is in alignment with the p-type a-Si in order to minimize the band bending at the TCO and p-type a-Si interface, and to reduce contact resistance and maximize open circuit voltage. For example, the work function of ITO is between 4.5 eV and 4.8 eV. This will cause band bending at TCO and p-type a-Si interface, and make it hard to achieve a low-resistance ohmic contact and high V oc . FIG. 2 presents a diagram illustrating the band diagrams at the interface between high/medium/low work function TCO material and p-type amorphous Si. From the band diagram, one can see that, for TCO material with low or medium work function, potential barriers at the interface make it harder for charges (holes) to migrate from the p-type a-Si material to the TCO, thus resulting in higher contact resistance. Hence, it is desirable to use a TCO material that has a relatively high work function.
[0032] FIG. 3 presents a diagram illustrating the process of fabricating a solar cell in accordance with an embodiment of the present invention.
[0033] In operation 3 A, a substrate 300 is prepared. In one embodiment, substrate 300 is a c-Si substrate, which is textured and cleaned. C-Si substrate 300 can be either p-type doped or n-type doped. In one embodiment, c-Si substrate 300 is lightly doped with an n-type dopant, and the doping concentration of c-Si substrate 300 can be between 1×10 16 /cm 3 and 1×10 17 /cm 3 . Note that other than using c-Si substrate (which is more expensive) as a base layer, it is also possible to deposit a thin c-Si epitaxial film on a relatively cheaper metallurgical-grade Si (MG-Si) substrate to act as a base layer, thus lowering the manufacturing cost. The thickness of the c-Si epitaxial film can be between 5 μm and 100 μm. The surface of c-Si substrate 300 can be textured to maximize light absorption inside the solar cell, thus further enhancing efficiency. The surface texturing can be performed using various etching techniques including dry plasma etching and wet etching. The etchants used in the dry plasma etching include, but are not limited to: SF 6 , F 2 , and NF 3 . The wet etching etchant can be an alkaline solution. The shapes of the surface texture can be pyramids or inverted pyramids, which are randomly or regularly distributed on the surface of c-Si substrate 300 .
[0034] In operation 3 B, a passivation layer 304 is deposited on top of c-Si substrate 300 . Passivation layer 304 can significantly reduce the density of surface carrier recombination, thus increasing the solar cell efficiency. Passivation layer 304 can be formed using different materials such as intrinsic a-Si or silicon-oxide (SiO x ). In one embodiment, a layer of intrinsic a-Si is deposited on c-Si substrate 300 to form passivation layer 304 . Techniques used for forming passivation layer 304 include, but are not limited to: PECVD, sputtering, and electron beam (e-beam) evaporation. The thickness of passivation layer 304 can be between 3 nm and 10 nm.
[0035] In operation 3 C, a heavily doped p-type doped amorphous semiconductor layer is deposited on passivation layer 304 to form an emitter layer 306 . The p-type amorphous semiconductor can be a-Si or amorphous SiC (a-SiC). In one embodiment, emitter layer 306 includes a-Si. The doping concentration of emitter layer 306 can be between 1×10 17 /cm 3 and 5×10 20 /cm 3 . The thickness of emitter layer 306 can be between 3 nm and 10 nm. Techniques used for depositing emitter layer 306 include PECVD. Because the thickness of emitter layer 306 can be much smaller compared with that of the emitter layer in a homojunction solar cell, the absorption of short wavelength light is significantly reduced, thus leading to higher solar cell efficiency.
[0036] In operation 3 D, a layer of high work function TCO material is deposited on top of emitter layer 306 to form TCO layer 308 . Compared with conventional TCO material, such as ITO, used in solar cells, TCO layer 308 includes TCO material with a relatively higher work function. In one embodiment, the work function of TCO layer 308 is between 4.9 eV and 6.1 eV. Examples of high work function TCO include, but are not limited to: GaInO (GIO), GaInSnO (GITO), ZnInO (ZIO), ZnInSnO (ZITO), their combinations, as well as their combination with ITO. Techniques used for forming TCO layer 308 include, but are not limited to: PECVD, sputtering, and e-beam evaporation. Note that in addition to providing low-resistance ohmic contact, the higher work function of TCO layer 308 can also result in a higher V oc .
[0037] In operation 3 E, metal front electrodes 310 are formed on top of TCO layer 308 . Front metal electrodes 310 can be formed using various metal deposition techniques at a low temperature of less than 300° C. In one embodiment, front electrodes 310 are formed by screen-printing Ag paste. In another embodiment, front electrodes 310 are formed by electroplating Cu and/or Ni.
[0038] In operation 3 F, a back electrode 302 is formed on the opposite side to the front side. In one embodiment, the back electrode stack can include a passivation layer, an n-typed heavily doped semiconductor layer, a TCO or a metal layer with relatively low work function (such as between 4.0 eV and 5.0 eV), and a metal grid.
[0039] After the formation of front electrodes 310 and back electrode 302 , various techniques such as laser scribing can be used for cell isolation to enable series interconnection of solar cells.
[0040] Although adopting high work function TCO material can result in lower contact resistance between TCO layer 308 and emitter layer 306 , high work function TCO material tends to have a larger resistivity than that of the ITO. For example, an ITO material that has 5% tin oxide has a low resistivity of 200 μΩ·cm, which is much smaller than that of the high work function TCO materials. Hence, to reduce the overall resistance, TCO layer 308 may be a bi-layer structure that includes a high work function TCO sub-layer and an ITO sub-layer.
[0041] FIG. 4 presents a diagram illustrating an exemplary solar cell in accordance with an embodiment of the present invention. Solar cell 400 includes a base layer 402 , a passivation layer 404 , an emitter layer 406 , a TCO layer 408 , a back-side electrode 410 , and a front-side metal grid 412 .
[0042] Base layer 402 can be a c-Si substrate or an epitaxially formed c-Si thin film. Passivation layer 404 can be an oxide layer or a layer of intrinsic a-Si. Emitter layer 406 can be either p-type doped or n-type doped. In one embodiment, emitter layer 406 is p-type doped a-Si. TCO layer 408 includes two sub-layers 408 - 1 and 408 - 2 . Sub-layer 408 - 1 is on top of emitter layer 406 . To ensure a good ohmic contact with a low contact resistance, in one embodiment, sub-layer 408 - 1 is formed using high work function TCO material, including, but not limited to: GaInO (GIO), GaInSnO (GITO), ZnInO (ZIO), ZnInSnO (ZITO), and their combinations. Sub-layer 408 - 2 includes TCO materials having low resistivity, such as ITO, tin-oxide (SnO x ), aluminum doped zinc-oxide (ZnO:Al), or Ga doped zinc-oxide (ZnO:Ga). Back-side electrode can include a passivation layer, an n-typed heavily doped semiconductor layer, a TCO or a metal layer with relatively low work function (such as that between 4.0 eV and 5.0 eV), and a metal grid. Front-side metal grid 412 can include screen-printed Ag grid or electroplated Cu and/or Ni grid.
[0043] In addition to be deposited on the front side (the side facing the sun) of the solar cell, the high work function TCO layer can also be used on the side opposite to the incidence of sunlight. In one embodiment, the passivation layer and the heavily doped p-type semiconductor layer are deposited on the back side of the c-Si base layer, facing away from incident light. The high work function TCO layer is then deposited on the back side as well. The electrode on the front side of the solar cell includes a TCO layer with lower work function, such as ITO. The solar cell performance can still benefit from the low ohmic contact resistance between the high-work function TCO and the heavily doped p-type semiconductor layer.
[0044] FIG. 5 presents a diagram illustrating an exemplary solar cell in accordance with an embodiment of the present invention. Solar cell 500 includes a base layer 502 , passivation layers 504 and 506 , an emitter layer 508 , a BSF layer 510 , TCO layers 512 and 514 , a back-side electrode 516 , and a front-side electrode 518 .
[0045] Base layer 502 can be lightly doped c-Si. In one embodiment, base layer 502 is p-type doped. Passivation layers 504 and 506 can include an intrinsic a-Si or oxide layer or a combination thereof. Emitter layer 508 can be heavily doped n-type amorphous semiconductor, and BSF layer 510 can be heavily doped p-type amorphous semiconductor, such as a-Si or a-SiC. Front-side TCO layer 512 interfaces with n-type doped emitter layer 508 , and includes low work function TCO material, such as ITO. Back-side TCO layer 514 interfaces with p-type doped BSF layer 510 , and includes high work function TCO material, such as GIO, GITO, ZIO, ZITO, and their combinations. Back-side electrode 516 and front-side electrode 518 are similar to the ones shown in FIG. 4 .
[0046] Note that it is also possible to place the heavily doped p-type emitter on the back side of the solar cell with a lightly doped n-type base layer, and to include a front surface field (FSF) layer. As long as the TCO material interfacing with heavily doped p-type material has a relatively high work function, the overall performance of the solar cell can benefit from the reduced ohmic contact resistance between the TCO and the heavily doped p-type material.
[0047] The foregoing descriptions of various embodiments have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention.
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One embodiment of the present invention provides a solar cell. The solar cell includes a Si base layer, a passivation layer situated above the Si base layer, a layer of heavily doped amorphous Si (a-Si) situated above the passivation layer, a first transparent-conducting-oxide (TCO) layer situated above the heavily doped a-Si layer, a back-side electrode situated below the Si base layer, and a front-side electrode situated above the first TCO layer. The first TCO layer comprises at least one of: GaInO, GaInSnO, ZnInO, and ZnInSnO.
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BACKGROUND OF THE INVENTION
A. Field of the Invention
The present invention relates to apparatus used to facilitate the laboratory production of small organic crystals in the approximate size range of 10 microns or less. More particularly, the invention relates to a micropositioner machine for extracting or “harvesting” individual micron-size protein crystals from a liquid in which the crystals are grown, and cryofreezing and storing the extracted crystals for subsequent crystallographic analysis.
B. Description of Background Art
The development of new therapeutic drugs by medical researchers, particularly those containing biochemicals, has in recent times benefited from an energizing technology in which individual protein crystals having particular structural characteristics are grown and tested for therapeutic efficiency. This technology is useful because of the discovery that interactions between proteins and other biochemicals with living organisms depend not only on the chemical composition of a biochemical, but also upon its physical structure. Thus, many biochemical reactions at the cellular level proceed at an accelerated rate if biochemical and cellular sites have complementary shapes, e.g., analogous to a triangular peg having an appropriate shape and size for fitting into a triangular recess, or vice versa. Conversely, a mismatch between the structures of a cellular binding site and a biochemical characterized by non-complementary shapes, results in situations somewhat analogous to trying to fit a square peg into a round hole. In such cases, the reaction rate between a cell and a biochemical may be unacceptably low.
For the foregoing reasons, medical and biochemical researchers have devoted increased attention to techniques for producing individual crystals, such as protein crystals, which have specific shapes or other structural characteristics.
According to one technique for producing protein crystals with particular from which a crystal is to be grown, along with some sort of agent such as a fragment of a crystal of the type to be grown, to act as a seed for initiating crystallization from the liquid, which is sometimes referred to as a liquor.
Typically, protein crystals having selected structures are developed by growing individual crystals from liquid contained in small individual wells formed in the upper surface of a plate. Typical plates used for the cultivation of protein crystals are rectangularly shaped, flat plates which are several centimeters on a side. Each plate has a matrix, typically rectangularly shaped, of separate, individual wells. For example, a 96-well “sitting-drop” plate may have 96 wells, each capable of holding a one-micro liter drop of crystal growth solution. Another typical cell cultivating plate has 24 2-micro liter wells.
After each well in a crystal growth plate has been filled with a desired volume of a crystal growth cocktail, a predetermined time period is allowed to elapse to thereby enable growth of crystals in each cell. The crystal growth plate is then positioned in the field of view of a stereo microscope, as a first step in extracting or “harvesting” individual crystals by a human or robotic operator.
According to a presently employed method of harvesting individual protein crystals from crystal growth wells, a human operator uses an elongated pick-up tool holder which has a small diameter planar pick-up loop protruding from its end. The pick-up or “harvester” loop sometimes referred to as a “cryoloop” is removably attached to the tool holder, has a diameter in the range of about 0.05 mm. to 1 mm., and is typically made of a looped filament of nylon, etched Kapton, or other hydrophobic material, which has a typical diameter of about 10 micrometers.
With the aid of the microscope, the human operator looks into the liquid cocktail to determine if one or more crystals are present. If more than one are present, they may be attached to each other and therefore need to be separated. The separation may be accomplished manually using a very small knife blade. Alternatively, the knife blade may be mounted on the tool arm of the micro manipulator machine for finer position control to separate the crystals.
With the aid of the microscope, the human operator inserts the harvester cryoloop into a solution in a well in which the crystals are grown, at an oblique angle to encircle a crystal contained in the solution. The tool, with the cryoloop and an attached liquid drop containing a crystal suspended in the solution by surface tension of the liquid, is then withdrawn upwardly from the crystal growth well.
A final step in harvesting individual crystals includes freezing a cryoloop holding a liquid drop and a crystal by exposing the loop and drop to a stream of a cryogenic gas, such as nitrogen evaporated from liquid nitrogen. This action, referred to as cryocooling or cryofreezing, freezes the crystals, liquid and cryoloop together, whereupon the cryoloop is removed from the tool holder, and placed in a cryogenic storage compartment cooled by a cryogenic fluid such as a liquid nitrogen or liquid propane.
Individual cryoloops each containing a crystal are subsequently analyzed by X-ray diffraction methods to determine whether the crystal has desired structural properties.
Because of the small sizes of protein crystals and the drops of liquid from which they form, it can be readily appreciated that the task of harvesting and storing the crystals requires moving the cryoloop in very small, precisely controllable increments. Accordingly, it would be desirable to provide an apparatus which has a capability for precisely manipulating a small cryoloop to extract small liquid drops containing protein crystals from growth wells, and cryofreezing the loop, liquid drop and crystals en masse for subsequent X-ray diffraction analysis and processing.
A method of Operator-Assisted Harvesting Of Protein Crystals Using A Universal Micro Manipulating Robot was described in an article of that title appearing in the Journal of Applied Crystallography (2007) 40. pp. 539-545. The entire contents of that article, which are directed to a fully automatic crystal harvesting method, are incorporated by reference into the present application.
The present invention was conceived of in part to provide a micro-manipulator machine for crystal harvesting which could substantially enhance the speed and precision with which a human operator could perform harvesting and preservation of protein crystals from small individual crystal growth wells.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which facilitates manipulation of a tiny filamentary cryoloop tool to extract micro-liter size drops of liquid containing a selected crystal from micro-liter size crystal growth wells.
Another object of the invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which includes a micropositioner mechanism that utilizes a manually operable input control arm coupled through a mechanical linkage mechanism to a follower mechanism on which is mounted a tool holder support arm having at a front outer end thereof a tool head for releasably holding a cryoloop useable for crystal harvesting, the linkage mechanism being so constructed as to cause the tool holder to move translationally in small fractions of displacements of a hand-manipulatable position control knob attached to the end of the control arm, thus enabling a cryoloop held in the tool holder to be precisely manipulated in motion increments which are fractional ratios of motions of the position control knob.
Another object of the invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which includes a micropositioner mechanism that uses a pantograph-type motion divider mechanism for translationally moving a cryoloop at the tip of a tool head in coordinate displacements in a work space which are predetermined fractional ratios of translational motions in a control space input by hand motions of a human operator to a position control knob, and which includes a rotary actuator mechanism for rotating the tool holder arm to thus rotate a cryoloop at the end of the arm to adjustable inclination angles.
Another object of the invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which includes a micropositioner mechanism that mechanically couples motions of a manually graspable position control knob at an input end of a motion control mechanism input control arm to a follower mechanism which has coupled thereto a tool arm and tool head that is moved translationally in co-ordinate directions in response to motions of the input position control knob, but at fractional ratios of displacements of the position control knob, and which includes a tool head angle control mechanism that enables the vertical inclination angle of a cryoloop held in the tool head to be remotely controlled by an angle control knob located on the input control arm near the position control knob.
Another object of the invention is to provide a micro-manipulator machine for crystal harvesting and cryofreezing crystals which includes a micropositioner mechanism for moving a tool head and protruding cryoloop in a work space above a work platform located remotely from a position control knob, in precisely scaled fractional ratios of motions of the position control knob in an input control coordinate space, and a rotary actuator mechanism for rotating the tool head and cryoloop to adjustable angles relative to a vertical axis through the tool holder and work table. Another object of the invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which includes a micropositioner mechanism for translationally moving a tool head and cryoloop mounted therein in a work space above a work platform in response to movements of a remotely located position control knob, an angle control actuator responsive to movements by a human operator of an angle control knob coupled to an angle control encoder located near the hand control knob for adjusting an inclination angle of the tool head and cryoloop relative to a vertical axis of the work platform; and a tool arm support crank mechanism for orbitally moving the tool head and cryoloop upwards from the work platform towards a docking station and thus repositioning the tool head and cryoloop from a downwardly angled work orientation close to the work platform to a vertically upwardly oriented access position above the platform.
Another object of the invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which includes a micropositioner mechanism for remotely positioning the translational position of the tip of a cryoloop held in a tool holder above a work platform, an angle control mechanism for controlling the inclination angle of the cryoloop, a tool arm support crank mechanism for orbitally moving the tool head and cryoloop upwards from the work platform towards a docking station, and thus positioning the tool head in an upwardly pointing orientation for removal and replacement of a cryoloop held within the holder, when the micropositioner mechanism has been used to move the tool head to an upward, horizontally centered location at which a docking arm protruding from the tool head support mechanism is proximate a docking site.
Another object of the invention is to provide a micro-manipulator machine for harvesting and cryofreezing crystals which includes a micropositioner mechanism for remotely controlling the vertical and lateral and fore-and-aft horizontal positions of a tool head holding a crystal harvester cryoloop, an angle control mechanism including a rotary actuator for controlling the inclination angle of the cryoloop relative to crystal growth wells in a plate placed on a work platform below the tool head, a docking station for contacting a docking arm of the micropositioner mechanism when the tool head has been moved upwards from a crystal growth well after the cryoloop has been inserted into a drop of liquid to thereby encircle and hold by surface tension a crystal, and retracted from the well, a tool arm support crank mechanism for orbitally moving the tool arm and head vertically upwards a substantial predetermined position above the work platform and proximate the docking station when the cryoloop has been withdrawn a predetermined distance upwards from the crystal growth well, and a pivoting mechanism for pivoting the tool head from an upward vertical orientation to an upward laterally inclined position to thereby displace a pivotable shutter from a position blocking a cryogenic gas stream for a selectable predetermined time period sufficient to enable cryogenic gas to freeze the liquid drop, crystals and cryoloop, the pivoting mechanism then pivoting the tool head to an upright vertical position to thus allow the pivotal shutter to return to a position blocking flow of cryogenic gas and enable removal of the cryoloop and frozen liquid drop and crystals for storage in a cryogenic storage area, and replacement of the removed cryoloop with a new cryoloop to enable subsequent crystal harvesting.
Various other objects and advantages of the present invention, and its most novel features, will become apparent to those skilled in the art by perusing the accompanying specification, drawings and claims.
It is to be understood that although the invention disclosed herein is fully capable of achieving the objects and providing the advantages described, the characteristics of the invention described herein are merely illustrative of the preferred embodiments. Accordingly, I do not intend that the scope of my exclusive rights and privileges in the invention be limited to details of the embodiments described. I do intend that equivalents, adaptations and modifications of the invention reasonably inferable from the description contained herein be included within the scope of the invention as defined by the appended claims.
SUMMARY OF THE INVENTION
Briefly stated, the present invention comprehends a micro-manipulator machine for harvesting and cryofreezing small crystals contained in small drops of liquid.
The machine according to the invention includes a manually operable micropositioner apparatus for remotely and precisely positioning the tip of a tool held in a tool head in a three-dimensional work space located above a tabular work platform which extends forward from a lower part of a front control panel of the machine.
In a preferred embodiment of a micro-manipulator machine for harvesting and cryofreezing crystals according to the present invention, the micropositioner apparatus includes an elongated, fore-and-aft disposed, generally horizontal input control arm coupled by a motion-dividing, pantograph-type bar-linkage coupler mechanism to a follower mechanism which supports a tool head support arm mount assembly. The tool head support arm mount assembly has protruding forward therefrom an elongated, straight tool head support arm which is parallel to the control arm, and protrudes forward through a central clearance opening in a front control panel of the machine that is located above and laterally displaced to the left of the control arm. The control arm protrudes forward of the front control panel, at a location offset to the right of the work platform. A tool head located at the front, outer end of the tool head support arm removably holds a tool, such as a cryoloop.
According to the invention, the linkage mechanism of the micropositioner is constructed so as to cause the cryoloop held in the tool holder to move translationally in three orthogonal directions in a three dimensional work space, motions of the cryoloop being predetermined fractional ratios of motions in a three-dimensional control space of a position control knob attached to the front end of the input control arm, the position control knob being manually manipulatable by a human operator.
According to the invention the tool head support arm, which preferably has a hollow tubular construction, protrudes forward in a generally horizontal direction from the tool head support arm mount assembly, and through the clearance opening through the front control panel of the machine. The tool head support arm is disposed coaxially through a tubular bearing support attached to the tool head support arm mount assembly.
An outer, front end of the tool head support arm has attached thereto an L-shaped tool head which holds a cryoloop. The tool head has a short, straight rear, longitudinally disposed leg fastened to the tool head support arm, and a short front transversely disposed leg which protrudes perpendicularly from the front end of the rear leg, and is thus disposed radially to the tool head support arm and lies generally in a vertical plane.
The front transverse leg of the L-shaped tool head has located in a transversely disposed outer end thereof a cylindrically-shaped socket for removably holding by magnetic force a cylindrically-shaped cryoloop support cap. The support cap has disposed axially inwardly from an outer frusto-conically shaped transverse face thereof a centrally located blind cryopin mounting bore.
The cryopin mounting bore is provided for receiving the inner end of a straight cryoloop pin which has protruding from an outer end thereof a small, planar cryoloop made of a thin filament of nylon, Kapton or the like. The plane of the loop is oriented generally parallel to the longitudinal axis of the cryoloop pin, and the cryoloop support cap is manually rotatable about its axis to orient the plane of the loop at selectable azimuth angles with respect to the co-linear axes of the outer, transverse leg of the tool holder, the cryoloop support cap and the cryoloop pin. As will be explained below, the cryoloop is used to extract or “harvest” a drop of liquid containing a crystal held in the liquid drop by surface tension, from individually selected wells of a crystal growth plate, by obliquely inserting the cryoloop into liquid in a well to encircle a selected crystal. The crystal is trapped in the cryoloop by surface tension, whereupon the cryoloop and liquid drop containing the crystal are withdrawn from liquid in a well.
The micro-manipulator machine for harvesting and cryofreezing crystals according to the present invention includes a rotary actuator mechanism for orbitally moving the tool head support arm and rotating the arm about its longitudinal axis to thus pivot the transverse output leg of the tool head and attached cryopin to various orbital angles relative to the tool head support arm, thus adjusting the vertical inclination angle of the cryoloop relative to a crystal growth well. The rotary actuator mechanism includes a rotary stepper motor coupled through a C-shaped yoke crank to a rear, inner end of the tool head support arm at a location behind the front panel of the machine and within an enclosure, rotation of the crank causing orbital motion of the tool arm.
The micro-manipulator machine according to the invention also includes a rotatable cryoloop inclination-angle control knob mechanically coupled to a shaft-angle encoder, which is in turn coupled electrically through machine control electronics to the tool support arm stepper motor. In a preferred embodiment, the cryoloop inclination-angle control knob and shaft-angle encoder are mounted on a front, outer end of the input control arm, near the position control knob.
According to the invention, the machine control electronics is configured to enable remote adjustment of the cryoloop inclination angle to a desired value, and includes a cryoloop Tool Angle Save control switch located on the front panel of the machine for storing that value. This arrangement enables an operator to rotate the cryoloop angle control knob to thus remotely adjust the inclination angle of the tool head and a cryoloop held in the tool head, relative to the upper horizontal surface of the work platform, which protrudes horizontally forward from a lower front portion of the machine.
Rotational adjustment of the tool head enables the operator to adjust the inclination angle of a cryoloop held in the tool head relative to a liquid drop in a selected one of an array of crystal growth wells in the upper surface of a crystal growth plate placed on the work platform. By operating the Tool Angle Save switch on the front panel of the machine, the cryoloop inclination angle data is saved in electronic memory so that positioning the cryoloop into a downward position above the work table will automatically restore the inclination angle of the cryoloop to a preset, saved value stored in memory.
The micro-manipulator machine according to the present invention includes a tool arm support crank mechanism for semi-automatically moving the tool arm a relatively large vertical distance above the work platform after the micropositioner has been used to manipulate the tool head in precisely controllable small translational motions to thus extract a liquid drop and crystals from a well.
The tool arm support crank mechanism includes a crank having the shape of a C-shaped yoke which has a pair of parallel front and rear vertically disposed arms which depend perpendicularly outwards from a longitudinally disposed upper base bar of the yoke. The front and rear arms have located between inner facing vertical sides thereof a rectangularly-shaped space in which is located a stepper motor. The stepper motor, which is attached to the front portion of a tool head support arm support mount assembly plate, has generally a cylindrical shape and a fore-and-aft disposed armature shaft which is parallel to the base bar of the crank yoke.
The rotatable shaft of the stepper motor is attached at the rear end thereof to the outer, lower end of the rear crank yoke arm. The rear end of the tool head support arm has a rearwardly extending coaxial shaft extension which is rotatably supported by front and rear longitudinally aligned bearings in the longitudinally disposed upper base bar of the crank yoke.
The tool head support arm has mounted coaxially thereon a cam wheel located forward of the front crank yoke arm. The front transverse leg of the tool head and cryoloop mounted therein are resiliently biased to be held in parallel alignment with the front and rear yoke arms by a cam follower button which is mounted to the front yoke arm and urged into a depression in the cam wheel by a leaf spring attached to the front yoke arm.
The tool arm cam and spring arrangement maintains the front transverse leg of the tool head and a cryoloop held in the tool head in parallel alignment with front and rear transversely disposed legs of the crank yoke. Thus, the cryoloop inclination angle is controlled by the rotational angle of the stepper motor armature shaft but is rotatable with respect to the yoke arm to enable the tool head and cryoloop to be pivoted momentarily towards a cryofreezer station, to thus allow cryogas to impinge on a liquid drop held in the cryoloop. The pivot mechanism which enables this action includes a transversely disposed pinion gear attached to the rear end of the shaft extension of the tool head support arm, the shaft extension being longitudinally disposed through front and rear aligned support bearings located in front and rear longitudinally aligned locations of the longitudinally disposed crank yoke base bar.
The tool head pivoting mechanism includes a convex transversely disposed sector gear which protrudes vertically upwards from the cylindrical housing of the stepper motor. The sector gear has longitudinally disposed teeth and grooves located on a circular arc segment, and is vertically centered on a longitudinally disposed vertical center plane of the stepper motor housing. The teeth of the sector gear, which has an arc length of about 20 degrees, are transversely aligned with the teeth of the pinion gear attached to the rear shaft extension of the tool head support arm.
The tool head orbiting and pivoting mechanisms of the rotary actuator mechanism function as follows.
After the micro manipulator mechanism has been used to withdraw a liquid drop from a crystal growth well by precise, small translational motions of the tool head in response to motions of the manually operated micropositioner position control knob, the operator manipulates the micropositioner position control knob to thus move the cryoloop a larger, vertical distance above the work platform. At a predetermined vertical distance, an electro-optical sensor attached to the miropositioner follower mechanism is actuated and sends a signal to control electronics. In response to this signal, the control electronic outputs a drive signal to the stepper motor. The stepper motor then rotates the yoke crank through a predetermined counterclockwise angle sufficient for the tool head and cryoloop to be orbited counterclockwise from a lower right-hand, harvesting location to an upper left docking location. Orbital motion of the yoke crank also causes the tool head and cryoloop to be repositioned from a downwardly angled orientation to a vertically upward orientation.
The operator then manipulates the position control knob to move the tool arm a further short distance upwardly and to the left, and then downwards until a perceptible physical contact is made between a docking arm protruding obliquely from the tool arm support assembly and an electrical switch located on the docking station fixedly attached to a stationary support plate of the machine.
Actuation of the docking station switch causes the control electronics to send a signal of a predetermined, selectable time duration to the stepper motor. That signal causes the stepper motor shaft to rotate a small additional counterclockwise angular increment, i.e., about 20 degrees, causing the pinion and sector gears to mesh, and thereby causing the tool head to tilt or pivot about 20 degrees counterclockwise. This action in turn causes a cam follower roller mounted on the tool head arm at the outer radial end of a bracket located rearward of the front transverse leg of the tool head to push leftwards against a cam bar protruding from the right side of a pivotable cryogas shield shutter. This motion in turn causes the cryofreeze shutter to pivot away from a position obstructing flow of cryogas for a predetermined period, thus enabling flow of cryogas onto the cryoloop and liquid drop for the predetermined time period. At the end of the time period, the stepper motor shaft is rotated 20 degrees clockwise to its previous position, in which the tool head and cryoloop are vertically upwardly oriented. Clockwise motion of the tool head enables the cryofreeze shutter to return to a rest position in which flow of cryogenic gas is blocked. In the upright vertical position, the cryopin and cryoloop may be removed by the operator and placed in cryostorage.
The micro-manipulator machine according to the present invention includes a stereoscopic microscope which protrudes from an upper front part of the machine, the microscope having a pair of objective lenses which are positionable at adjustable distances above the center of the work platform. By viewing a crystal growth plate through the stereo microscope, a human operator may manipulate the position control knob to thus remotely position a cryoloop above a selected crystal growth well in the upper surface of the plate, move the tool head downwards to thus insert the cryoloop at a selected inclination angle into a liquid drop containing crystals located in the well, and retract the tool head upwards to thus withdraw a crystal-containing liquid drop adhered to the loop by surface tension from the well.
In a preferred embodiment of the invention, the work platform has a flat upper surface which has a centrally located light-transmissive window below which is located an adjustable intensity light source. Also, the platform preferably includes a jack mechanism that enables the height of the platform to be adjusted relative to a base plate of the machine supported by a laboratory bench or table top on which the machine is placed. This arrangement facilitates viewing and manipulating crystals in drops located in the wells of transparent crystal growth plates of various heights.
The micro-manipulator machine according to the present invention also includes a cryofreezer apparatus for cryofreezing en masse a cryoloop and crystal-containing liquid drop, to thereby preserve crystals for subsequent crystallographic analysis, as will now be described.
According to the invention, the micro-manipulator machine is provided with a cryofreezer station located above and offset to the left of the center of the work platform. The cryofreezer station includes a hollow cryogas supply tube which is located above the left side of the work platform, and protrudes to the right. A continuously flowing supply of a cryogenic gas such as cold nitrogen gas evaporated from a tank of liquid nitrogen is conveyed through the cryogas supply tube from a cryogas supply apparatus.
The cryofreezer station includes a shutter mechanism that has a generally vertically disposed shutter or shield plate attached to the right-hand end of a shutter arm, which is pivotably mounted to the transversely disposed, vertical outer face of the shutter arm. The shield plate includes a vertically disposed shutter blade mounted perpendicularly to the laterally inwardly located right-hand end of the shutter arm, which is biased by the weight of a portion of the arm located to the left of the pivot axis of the arm, to a horizontally disposed orientation. In that position, the shield plate obstructs lateral flow of cryogenic gas.
The shutter mechanism according to the invention includes a curved cam bar which protrudes rightward from the shutter plate. In response to a counterclockwise pivotal motion of about 20 degrees of the cryoloop support tool head, the tool head cam follower roller pushes against the cam bar, thus causing the cryofreezer shutter arm to rotate a corresponding angular increment in an opposite, clockwise sense. Pivotal rotation of the shutter plate causes it to move downwards from an upper position in which a stream of cold nitrogen gas is obstructed from flowing to the right, to a lower position which allows a stream of cold nitrogen gas to contact the cryoloop, which is tilted about 2 degrees counterclockwise into the stream, thus freezing the cryoloop, liquid drop and a crystal contained therein.
According to the invention, the cryoloop support tool head remains tilted to expose the cryoloop to the flowing cryogenic gas for an operator-preselected period of time, e.g., 0.2 second to 4 seconds or longer if required, sufficient to freeze the liquid drop, crystal and cryoloop en masse.
The micro-manipulator machine according to the present invention is so constructed as to facilitate semi-automatic operation of the cryofreezer mechanism. Thus, the machine includes a switch located at a docking site of the tool holder support arm, which outputs a signal to the control electronics, which in turn outputs a 2-degree tilt command signal to the rotary actuator of the tool head support arm.
The docking site switch, which is attached to a docking station fixed to the machine support structure located behind the front control panel of the machine, is actuated by contact with a docking arm which protrudes obliquely from the tool support arm, when the arm has been moved upwardly, to the left, and down slightly.
When the tool head support arm has been moved upwards from the work platform sufficiently to withdraw a cryoloop and liquid drop from a crystal growth well a predetermined distance, a tool arm height sensor outputs a signal to the control electronics which outputs a command signal to the tool head rotary actuator mechanism to orbit the tool head to an upper left location, at which location the tool head and cryoloop are vertically upwardly oriented. Then, when the input control arm is manipulated to thus move the tool support arm a small distance upwards and to the left, to thus position the cryopin and cryoloop adjacent to the shutter cam bar, a slight downward motion of the position control knob causes the docking arm to move downwards and thus contact the docking site switch. Contact of the docking arm with the docking site switch produces a command signal to the stepper motor driver of the rotary head actuator to tilt the tool head counterclockwise, pivoting the cryofreezer shutter clockwise to an unblocking position enabling flow of cryogenic gas to thus expose the cryoloop to flowing cryogenic gas for an operator-preselected time interval, as described above.
After expiration of the preselected time interval, the rotary actuator automatically pivots the tool head clockwise back to an upright vertical position, enabling the cryofreeze shutter to pivot counterclockwise to an orientation in which the cryofreeze shutter blocks flow of cryogenic gas. At this position, the cryopin, cryoloop and frozen liquid drop and crystal may be manually removed from the tool head, and placed in a cryogenic storage container. A new cryopin and cryoloop may then be inserted into the cryopin support cap, to enable harvesting new crystals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a micro-manipulator machine for harvesting and cryofreezing crystals according to the present invention, showing an enclosure cover panel thereof removed.
FIG. 2 is a fragmentary front elevation view of the machine of FIG. 1 , showing a stereo-microscope thereof removed.
FIG. 3 is a right-hand upper perspective view of the machine of FIG. 1 , showing an upper enclosure cover panel thereof removed.
FIG. 4 is a fragmentary rear perspective view of the machine of FIG. 1 .
FIG. 5 is a left-hand upper perspective view of the machine of FIG. 1 .
FIG. 6 is an electrical block diagram of the machine of FIG. 1 .
FIG. 7 is a front perspective view of the machine of FIG. 1 , showing a tool arm and tool head thereof moved to an upper, upright location to enable placement of a crystal growth plate on a work platform of the machine, and enable installation of a cryoloop in the tool head.
FIG. 8 is a fragmentary, partly diagrammatic front perspective view of the machine of FIG. 1 , showing the manner of installing and orienting a cryoloop pin and support cap in the tool head of the machine.
FIG. 9 is a view similar to that of FIG. 8 , showing a tool head support arm and tool head of the machine moved downwards towards the work platform of the machine, preparatory to using a cryoloop installed in the tool head to extract crystals from crystal growth wells in a crystal growth plate placed on the work platform.
FIG. 10 is a view similar to that of FIG. 9 , showing the adjustability of the vertical inclination of the tool head, preparatory to inserting the cryoloop into a selected well to harvest a liquid drop containing crystals.
FIG. 11 is a view similar to that of FIG. 10 , showing the tool arm and tool head moved upwards from the platform towards a docking station of the machine, after withdrawing a liquid drop containing crystals from a crystal growth well.
FIG. 12 is a view similar to that of FIG. 11 , showing the tool head momentarily pivoted counterclockwise to thus rotate a cryoshutter clockwise and thereby enable a stream of cryogas to impinge on the liquid drop held in the cryoloop.
FIGS. 13-15 are fragmentary, partly diagrammatic rear perspective views of a tool arm orbital yoke crank and tool head pivot mechanism, showing the disposition of the mechanisms for the tool head orientations shown in FIGS. 10-12 , respectively.
FIG. 16 is a fragmentary right-side elevation view of the machine of FIG. 1 , showing the micro-manipulator control arm and follower thereof in a lower-most, right-most dispositions, and showing in phantom upward triggering dispositions, of the control arm and follower.
FIG. 16A is a view similar to that of FIG. 16 , but showing tool arm components of the machine removed for clarity.
FIG. 17 is an upper plan view of the arrangement of FIG. 16 .
FIG. 17A is a view similar to that of FIG. 17 , but showing tool arm components of the machine removed for clarity.
FIG. 18 is a view similar to that of FIG. 16 , but showing the control arm and follower in an uppermost and leftward disposition.
FIG. 18A is a view similar to that of FIG. 18 , but showing tool arm components of the machine removed for clarity.
FIG. 19 is an upper plan view of the arrangement of FIG. 18 .
FIG. 19A is a view similar to that of FIG. 19 , but showing tool arm components of the machine removed for clarity.
FIG. 20A is a fragmentary view of the machine of FIG. 1 , partly in longitudinal section, showing a tool head support arm and tool head thereof orbited downwards and rightwards to position a cryoloop held in the tool head is proximity to a work platform of the machine, in a crystal harvesting position.
FIG. 20B is a fragmentary front elevation view of the arrangement of FIG. 20A , showing a tool angle biasing cam and follower spring thereof.
FIG. 21A is a view similar to that of FIG. 20A , but showing the tool head support arm and tool head oriented to an upper left position.
FIG. 21B is a fragmentary front elevation view of the arrangement of FIG. 20A , showing the disposition of the tool angle biasing cam and follower spring rotated counterclockwise as viewed from the front of the machine.
FIG. 22 is a fragmentary sectional view of the tool arm support head and tool head, and cryoloop pin of the machine of FIG. 1 , showing an optional vacuum tube accessory thereof.
FIG. 23 is a fragmentary right side perspective view of the machine of FIG. 1 , with the tool arm and tool head thereof oriented in and positioned at a lower, crystal harvesting location, as shown in FIG. 10 .
FIG. 24 is a view similar to that of FIG. 23 , showing the tool arm and tool head thereof oriented and positioned at an upper, crystal retrieval position, as shown in FIG. 11 .
FIG. 25 is a fragmentary front perspective view of the machine of FIG. 1 , showing the tool arm and tool head moved towards a docking station, corresponding to the orientation of the tool head shown in FIG. 11 .
FIG. 26 is a fragmentary front perspective view of the machine of FIG. 1 , on an enlarged scale and showing contact of docking arm thereof with a docking station.
FIG. 27 is a fragmentary front perspective view of the machine of FIG. 1 , showing the tool arm and tool head thereof oriented as shown in FIG. 12 , showing the tool head automatically and momentarily pivoted counterclockwise to thus expose the tool head to flowing cryogas.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-27 illustrate various aspects of the structure and functions of a micro-manipulator machine for harvesting and cryofreezing crystals according to the present invention. The machine according to the present invention includes a micropositioner apparatus manually operable by a human operator to precisely position a remotely located tool head holding a cryoloop used for crystal harvesting.
The micropositioner apparatus includes an input control arm which protrudes forward from the right side of the machine, and which is terminated at an outer, front end of the control arm by a hand-graspable position control knob.
The micropositioner apparatus contains a mechanical linkage mechanism which causes a tool head holding a cryoloop to move translationally in orthogonal directions in a three-dimensional work space located above a work platform in precise fractional ratios of movements of the position control knob in a remotely located command input control space. The micropositioner thus enables a cryoloop mounted in the tool head to be remotely manipulated to thus insert the cryoloop into a selected one of a plurality of small crystal growth wells in a crystal growth plate supported on the work platform, retract the cryoloop from the well with a liquid drop containing a selected crystal, and move the cryoloop upwardly and to the left to a docking station and cryofreezer station comprising part of the machine.
A suitable micropositioner apparatus for use in the machine of the present invention is a modification of the “Micropositioner For Ultrasonic Bonding” described in U.S. Pat. No. 5,871,126. The entire disclosure of that patent is hereby incorporated by reference into the present disclosure.
Referring first to FIGS. 1-5 , it may be seen that a micro-manipulator machine 30 for harvesting and cryofreezing crystals includes a laterally elongated, rectangular rear base plate 31 which supports a micropositioner 32 and other components of the machine. The machine 30 includes a front rectangular base plate 33 of a size and shape similar to that of rear base plate 31 . The front base plate protrudes forward from a front vertical wall 34 of the rear base plate, and has a horizontal upper surface 35 parallel to upper surface 36 of the rear base plate.
Machine 30 includes a work platform 37 which has a size and outline shape similar to that of front base plate 33 . Work platform 37 has a flat, horizontal upper work surface 38 which overlies upper surface 35 of front base plate 33 , at a height controllable by a height adjustment knob 39 , which protrudes forward from front edge wall 40 of the front base plate. The height adjustment knob 39 is coupled through a shaft (not shown) to a work platform elevator jack (not shown) located between the lower surface 43 of the work platform and the upper surface 35 of the front base plate.
As shown in FIGS. 1 and 2 , work platform 37 of machine 30 has located in a central circular aperture 45 through its thickness dimension a circular light-transmissive diffuser window 46 , an upper flat surface 47 of which is flush with upper surface 38 of the work platform. Machine 30 includes a light source 48 below window 46 which is connected to an electrical power source through an intensity control rheostat 49 mounted on a right vertical side plate 50 of work platform 37 .
Referring still to FIGS. 1-6 , it may be seen that machine 30 includes a laterally elongated, rectangular front control panel 51 which extends perpendicularly upwards from a junction plane between rear vertical edge wall 44 of front base plate 33 and the front vertical edge wall of rear base plate 31 . As shown in FIG. 3 , front control panel 51 has a short vertical lower base portion 52 and a longer, rearwardly angled upper portion 53 .
As shown in FIGS. 1-5 , micropositioner apparatus 32 includes a generally horizontally disposed input control arm 55 which protrudes forward from an outer, right-hand end of a generally laterally disposed straight beam component 56 A of a parallelogram linkage bar assembly 56 of the micropositioner apparatus. As shown in the figures, lateral beam 56 A has a rectangular cross-sectional shape, and a skeletonized construction.
The parallelogram linkage bar assembly 56 , which is also generally horizontally disposed, protrudes laterally outwardly towards the right from an opening 58 in a right-side of machine 30 , above rear base plate 31 . Thus, input control arm 55 is disposed in a generally fore-and-aft direction in a horizontal plane, offset to the right of right-hand side wall 59 of machine 30 . As shown in the figures, input control arm 55 has the shape of a long straight shaft which is terminated at a front, free end thereof by an axially mounted, spherically-shaped position control knob 57 .
Referring to FIGS. 3 , 4 and 17 A, it may be seen that an inner, output end 60 of lateral beam 56 A parallelogram bar linkage assembly 56 of micropositioner apparatus 32 is pivotably coupled through a follower mechanism 61 , tool head support arm support plate 62 and orbital actuator mechanism 101 including a yoke crank 102 to an elongated, straight, generally horizontally disposed tool head support arm 63 which protrudes forward through a rectangularly-shaped tool-head support arm clearance aperture 64 that is laterally centrally located in upper part 53 of front control panel 51 . Thus, tool head support arm 63 is disposed in a generally fore-and-aft direction, above and parallel to upper surface 38 of work platform 37 , and parallel to input control arm 55 .
As shown in FIGS. 16A-19A , a laterally inwardly located end 60 of micropositioner lateral beam 86 is pivotably supported by the right-hand face of a vertical support plate 72 , which protrudes upwardly from rear machine base plate 31 .
As may be seen best by referring to FIGS. 20A and 20B , tool head support arm 63 has disposed axially rearward therefrom an elongated, straight tool head support arm shaft extension 66 . The support shaft extension 66 has fastened coaxially to a rear end portion thereof a pinion gear 67 , the function of which will be described below. As will be described in detail below, yoke crank 102 is rigidly coupled to the output shaft 70 of a stepper motor 71 . In response to electrical drive signals received from a control electronics module 72 , stepper motor 71 incrementally rotates crank yoke 102 and tool head support arm 63 .
As shown in FIGS. 1-6 , and 22 , tool head support arm 63 has fastened to a front, outer end thereof an L-shaped tool head 73 . Tool head 73 has a short, straight, rear longitudinally disposed leg 74 which is axially aligned with and fastened to a front, outer end of tool head support arm 63 . Tool head 73 also has a short, straight front transversely disposed leg 75 which depends perpendicularly from the front end of rear leg 74 , i.e., in a radial direction relative to tool head support shaft 66 . Thus, front leg 75 is disposed generally in a vertical plane, and is pivotable in that plane by rotation of tool head support arm 63 .
As shown in FIGS. 7 , 8 , 22 and 25 , the front radially disposed leg 75 of tool head 73 has located in a transversely disposed outer end face 76 thereof a coaxially centrally located, blind socket 77 for removably holding by magnetic force provided by a magnet 78 (not shown) a cylindrically-shaped cryoloop support cap 79 . The cryoloop support cap 79 has disposed axially inwardly from an outer frusto-conically-shaped transverse face 80 thereof a central coaxial bore 81 . Bore 81 is provided for receiving the inner end portion of the shank 82 of straight cryoloop pin 83 . Cryoloop pin 83 has protruding from an outer transverse end 84 thereof a small, planar cryoloop 85 .
Cryoloop 85 consists of a thin filament of nylon, Kapton or other polymer, which is formed into a longitudinally elongated oval-shaped planar loop, opposite ends of the filament being arranged in a parallel, twisted configuration and inserted into a coaxial bore 86 extending longitudinally inwards into outer transverse face 84 of cryopin 83 . The filament diameter of a typical cryoloop 85 is about 10 microns, while the loop diameters range from about 0.05 mm to about 1.0 mm.
In an example embodiment of machine 30 that was tested by the present inventor, the cryoloop support cap 79 , cryoloop pin 83 and cryoloop 85 were obtained from the Hampton Research Corporation, 34 Journey, Aliso Viejo, Calif. 92656-3317. In the example embodiment, a pickup tool 87 consisting of Hampton Research Catalog No. HR4-747 cryoloop support cap 79 to which is permanently attached a threaded and bonded, solid 3 mm diameter copper cryoloop pin 83 was used. Bore 86 of cryoloop pin 83 had a diameter of about 0.65 mm, and was adapted to insertably receive a Cat. No. HR4-981 cryoloop 85 . As will be described below, the pickup tool 87 is used to harvest crystals by inserting the cryoloop 85 at the end of the fool into a well containing a liquid drop and crystals.
As shown in FIGS. 1-7 , machine 30 includes a tool head angle control mechanism 90 for remotely adjusting the axial rotation angle of tool head support arm 63 , and hence the vertical inclination angle of a cryoloop 85 held parallel to front transverse leg 75 of tool head 73 . The tool head cryoloop vertical inclination angle control mechanism 90 includes an electrical shaft angle encoder 91 which has protruding therefrom a shaft terminated at an upper end thereof by a, conically-shaped control knob 92 . The encoder 91 is mounted on an encoder support block 93 , the latter being longitudinally slidably mounted on micropositioner input control arm 55 .
As shown in the figures, shaft angle encoder support block 93 has a bifurcated clevis-like shape which includes front and rear laterally outwardly protruding front and rear arms 94 F, 94 B, which have therethrough front and rear longitudinally aligned bores 95 F, 95 B that are slidably mounted on control arm shaft 55 . A toggle clamp bar 96 located between front and rear arms 94 F, 95 B enables encoder support block 93 to be slid rearward of front micropositioner position control knob 57 to a desired position by a human operator, and locked in that position by pivoting toggle clamp bar 96 downwards.
In response to manual twisting of tool angle encoder knob 92 , shaft angle encoder 91 outputs an electrical signal through a flexible electrical cable 97 to control electronics module 98 . As shown in FIG. 6 , control electronics module 98 contains circuitry 99 which outputs stepper motor drive signals to tool head support shaft stepper motor 71 , which are effective in orbiting tool head support arm 63 and tool head 73 to selected rotation angles and thereby orient the tool head and cryoloop to selected vertical inclination angles.
As shown in FIGS. 1 and 7 , machine 30 includes a Tool Angle Save switch 88 mounted on font control panel 51 of the machine, and a Cryofreeze Time Duration digiswitch 89 also mounted on the front control panel. Both switches are electrically connected to control circuitry 99 in control electronics module 98 , the functional operations which will be described below.
Referring to FIGS. 4 , 20 A, 21 A and 24 , it may be seen that micro manipulator machine 30 includes a tool arm support crank mechanism 101 for semi-automatically orbitally moving the tool arm. Crank mechanism 101 is effective in orbitally moving the tool head 73 and cryoloop 85 from a downwardly inclined, crystal harvesting location as shown in FIG. 1 , to a docking site location above and to the left of the center of the machine, as shown in FIG. 25 .
As shown in FIGS. 4 , 20 A, 21 A and 24 , tool arm support crank mechanism 101 includes a crank 102 having the shape of a C-shaped clevis or yoke which has front and rear vertically disposed parallel arms 103 , 104 , which depend perpendicularly from a longitudinally disposed base bar 105 of the yoke. The front and rear yoke arms 103 , 104 have located between inner facing vertical sides 106 , 107 thereof a rectangularly-shaped space 108 in which is located a stepper motor 71 . Stepper motor 71 is attached to the upper surface 110 of tool head arm support mount assembly plate 62 , near a front transverse end 112 of the plate. Stepper motor 71 has a generally cylindrically-shaped housing 113 and a longitudinally disposed armature shaft 70 which is disposed parallel to base bar 105 of crank 102 .
Shaft 70 of stepper motor 71 is connected a rear end 115 thereof to the inner, upper end 116 of rear yoke arm 104 of crank yoke 102 . The rear shaft extension 66 of tool head support arm 63 is rotatably supported by front bearing 118 which extends inwards from the front surface 119 of front crank yoke upper base bar 105 .
Reduced diameter rear shaft extension 66 of tool head support arm 63 is coaxially aligned with the tool arm, and protrudes axially rearwards from rear surface 121 of the tool arm. The rear end of tool arm shaft extension 66 is rotatably supported by a rear bearing 120 . Tool arm shaft extension 66 has mounted coaxially at the front end 122 thereof a rotary cam wheel 123 which is adjacent to the front surface 119 of crank upper base bar 105 .
Front transverse leg 75 of tool head 73 and a cryoloop 85 mounted in the leg are resiliently biased to be held in parallel alignment with the front and rear yoke arms 103 , 104 by the following construction.
As shown in FIGS. 13 through 15 and 20 A- 21 B, machine 30 has a cam follower 124 which includes a leaf spring 125 that is mounted on front crank yoke arm 103 . Leaf spring 125 has a flat, elongated rectangular shape and is fastened at a lower end thereof to front crank yoke arm 103 , near a radially outwardly located end of the arm. As shown in FIG. 13-15 , leaf spring 125 has flat, parallel outer and inner surfaces 127 , 128 , which are disposed parallel to a fore-and-aft plane, i.e., perpendicular to front surface 103 A of front yoke arm 103 .
Leaf spring 125 is attached to an outer end of front yoke arm 103 by means of a rectangularly-shaped spring mounting block 129 which protrudes forward from front surface 103 A of the arm, near the radially outwardly located face 130 of the arm, and a screw 131 which is disposed through hole 132 through the lower end of the leaf spring, and tightened into a threaded bore 133 which penetrates an outer face 134 of the spring mounting block.
Referring to FIGS. 13 through 15 , it may be seen that leaf spring 125 has protruding laterally inwards from an upper free end thereof a rounded follower knob 126 which is urged resiliently into a concave depression 136 in the outer peripheral surface 137 of cam wheel 123 .
The cam and follower spring arrangement described above resiliently biases the tool head support arm shaft angle so that the front transverse leg 75 of tool head 73 , and a cryoloop held in the tool head are in alignment with the longitudinal axes of front and rear transversely disposed legs 103 , 104 of crank yoke 102 . Thus, the inclination angle of a cryoloop 85 held in tool head 73 may be adjusted by adjusting the orbital angle of yoke crank 102 , which is in turn adjusted by the azimuth or rotation angle of armature shaft 70 of stepper motor 71 . However, as will be described below, the cam and spring arrangement comprise parts of pivot mechanism 138 which enables tool head arm 63 and attached tool head 73 and cryoloop 85 to be pivoted momentarily away from parallel alignment with the front arm 103 of yoke angle 102 , against biasing tension provided by spring 125 . As will also be described below, pivot mechanism 138 of tool head support arm 63 enables the tool head arm and head 73 to be pivoted momentarily towards a cryofreezer station 139 , to thus allow cryogas to impinge on a liquid drop held in a cryoloop.
Referring to FIGS. 4 and 13 - 15 , it may be seen that tool head pivot mechanism 138 includes a transversely disposed sector gear 140 which protrudes vertically upwards from an outer cylindrical surface 141 of housing 142 of stepper motor 71 . Sector gear 140 has longitudinally disposed teeth 142 and grooves 143 located on a circular arc segment, and is vertically centered on a longitudinally disposed center plane of the stepper motor housing. The teeth of the sector gear 140 , which has an arc length of about 20 degrees, are transversely aligned with the teeth and grooves 144 , 145 off pinion gear 69 attached to the rear end of tool head arm support shaft 66 . As shown in FIGS. 16-22 , tool head arm support shaft 66 is disposed longitudinally rearwards through front and rear longitudinal bearings 146 , 147 in yoke crank base bar 106 . Thus, as will be described below, when stepper motor shaft 70 is rotated counterclockwise sufficiently far for pinion gear 69 to contact the right side of sector gear 140 , further counterclockwise rotation of the stepper motor shaft will cause the pinion gear and sector gear to mesh, thus causing tool arm support shaft 66 to rotate against the tension provided by cam and follower spring 123 and 125 .
Referring again to FIGS. 1-5 , it may be seen that machine 30 according to the present invention includes a stereoscopic microscope 150 . As shown in FIGS. 1 and 3 , stereoscopic microscope 150 is laterally centrally located with respect to work platform 37 of machine 30 , and has a lower generally frusto conically-shaped objective lens turret 151 which is positioned in axial alignment above central light transmissive diffuser window 46 of the work platform.
Objective lens turret assembly 151 of stereoscopic microscope 150 fits vertically downwards into a cylindrical bore 152 provided through a horizontally disposed rectangular-shaped support plate 153 which forms the outer leg 154 of an inverted L-shaped microscope support bracket 155 . An inner vertical leg 156 of microscope support bracket 155 is coupled through a rack-and-pinion elevator mechanism 157 , adjustable in height by a hand wheel 158 , to an obliquely upwardly and forwardly angled cantilever support bar 159 . The latter has a flat, horizontally disposed lower surface 160 which is fastened in flat overlying contact to the flat upper surface 161 of flat, horizontally disposed microscope mounting plate 162 which protrudes rearward from a rear inner wall 163 of front control panel 53 , the upper surface 161 being coplanar with the upper edge 164 of the front control panel.
Referring to FIGS. 1 and 3 , it may be seen that stereoscopic microscope 150 includes an ocular head structure 165 which has a cylindrically-shaped lower housing 166 that is coaxially aligned with lower objective lens turret 151 . Housing 166 has a lower, flat, annular ring-shaped shoulder flange 167 which joins the upper end of lower objective lens turret 151 , which is supported by the flat upper surface 168 of support plate 153 .
As shown in FIGS. 1 and 3 , ocular head structure 165 of stereoscopic microscope 150 has disposed forward from an upper end of a lower cylindrically-shaped housing 166 a box-shaped eyepiece mounting assembly 169 . The latter has a flat, horizontally disposed upper wall surface 170 , and a flat transversely disposed front rectangularly-shaped lens mount surface 171 which is disposed parallel to but angled downwardly from the upper wall surface. A pair of left and right eyepiece holder tubes 172 L, 172 R protrude perpendicularly upwards from the downwardly angled front lens mount surface 171 . Eyepiece holder tubes 172 L, 172 R hold ocular lens assemblies 173 L, 173 R, respectively, which are individually adjustable to compensate for differing focus distances of the left and right eyes of a human operator.
As shown in FIG. 1 , stereoscope microscope 150 also includes a focus control hand wheel 174 which protrudes from a right side wall 175 of the microscope, and which is used to bring into focus an image of a cryoloop 85 and a selected well 176 in the upper surface 177 of a crystal growth plate 178 placed on light transmissive window 46 of work platform 37 .
As shown in FIGS. 25 and 27 , machine 30 includes a cryofreezer apparatus 180 for cryofreezing en masse a cryoloop and a liquid drop containing a crystal held within the cryoloop.
Referring to FIGS. 11 , 12 , 25 , and 27 , it may be seen that cryofreezer apparatus 180 includes an elongated rectangular cross section shutter support beam 181 . Cryofreezer apparatus includes a source of liquid nitrogen 182 from which is boiled off cold nitrogen gas, which is input to a hollow, laterally disposed flexible cryogas supply tube 183 . The latter is connected at a rear input end thereof located behind front machine control panel 51 to a source ( 184 , not shown) of a cryogas, such as nitrogen gas evaporated from liquid nitrogen. Cryogas supply tube 183 extends from source 182 , horizontally towards the right, i.e., towards a vertical center plane of work platform 37 . An example of a suitable source 182 of cold nitrogen gas is the Model 700 series nitrogen gas cryostream cooler supplied by Oxford Cryosystems, 220 Wood Road, Braintree, Mass. 02184.
Cryofreezer apparatus 180 includes a shutter mechanism 185 which is attached to transverse outer face 183 of shutter support beam 181 . The shutter mechanism 185 includes a shutter arm 186 that has a straight, rectangular cross section bar member 187 which is pivotally mounted to front face 181 A of shutter support beam 181 by a pivot axle 188 which enables the shutter arm to pivot in a vertical plane.
Shutter mechanism 185 also includes a shutter 189 which joins a right-hand portion of shutter arm 186 , and which protrudes to the right of pivot axle 188 and the right-hand side wall 190 of shutter support beam 181 .
Shutter 189 includes a laterally disposed, vertical wedge-shaped support plate 191 that has a narrower inner, left-hand end part which is fastened to shutter arm 186 .
Shutter 189 also includes a fore-and-aft disposed, generally vertical shield plate 192 located at the inner, right-hand edge of shutter support plate 191 . As shown in FIG. 25 , shutter arm 186 of shutter mechanism 186 is maintained in a horizontal position by a counterclockwise torque moment exerted around pivot axle 188 by the weight of that portion of the shutter arm located to the left of pivot axle 188 . In this quiescent position, shield plate 192 located at the laterally inwardly located, right-hand end of the shutter arm is positioned in a fore-and-aft, generally vertically disposed position adjacent to the outlet orifice 193 of cryogas supply tube 183 , thus obstructing rightward horizontal flow of cryogas.
As shown in FIGS. 25 and 27 , shutter mechanism 185 includes a curved cam bar 194 which protrudes laterally outwards from the right side of shutter plate 192 , adjacent to its rear edge. Cam bar 194 , which has in front elevation view the shape of a reverse C-shape, has a convex, generally vertically disposed outer right-hand segment 195 .
As may be seen best by referring to FIGS. 5 , and 22 , 24 and 25 , tool head 73 has protruding radially from a location rearward of longitudinally disposed leg 74 thereof a cylindrically shaped cam follower roller 196 is mounted on the outer radial end of a support bracket 197 which is located behind and parallel to front transverse tool head leg 75 . Cam follower roller 196 is rotatable about a fore-and-aft disposed axle 198 parallel to tool head support arm 63 . Thus, when tool head 73 is positioned adjacent to cam bar 194 , and rotated counterclockwise, cam follower roller 196 pushes leftwards against outer right-hand segment 195 of cam bar 194 . This pushing motion causes shield plate 192 to pivot clockwise, thus allowing unobstructed flow of cryogas from cryogas tube 183 onto a cryoloop 85 held by tool head 73 .
As shown in FIG. 22 , tool head support arm 63 and tool head 73 preferably have a hollow construction including coaxial bores 210 , 211 , respectively, which are axially aligned. Optionally, bores 210 , 211 have disposed therethrough a vacuum tube 212 which is connectable at a rear, inner end thereof through a solenoid valve 213 (see FIGS. 4 and 6 ) to a vacuum source (not shown), and at a front, outer end to a crystal pick-up implement (not shown).
FIGS. 1 and 7 - 27 illustrate the manner of using machine 30 to harvest crystals from wells 177 of a crystal growth plate 178 , and cryofreezing the harvested crystals for cryogenic storage and subsequent crystallographic analysis, which is typically performed using an X-ray diffraction instrument.
As shown in FIGS. 24-26 , a first step in using machine 30 to harvest and cryofreeze crystals includes manipulating position control knob 57 of micropositioner apparatus 32 in an upward direction, to thus position tool head 73 in an upper position. The position control knob 57 is then manipulated slightly to the left of center and down slightly until a docking arm 200 which protrudes forward from laterally disposed beam 56 A 60 of micropositioner 32 bumps down against a docking site stationary member 201 which protrudes from vertical micropositioner support plate 72 . As shown in FIGS. 17 , 17 A, 19 and 19 A, docking arm 201 is pivotably mounted near a rear end thereof to lateral micropositioner beam 60 .
Contact of docking arm 200 with docking site member 201 actuates an electrical switch 202 which provides an input signal to electronic control circuitry 99 . In response to the signal from docking site switch 202 , electronic control circuitry 99 outputs an electrical command signal to tool head angle stepper motor 71 , which causes tool head support shaft 66 to rotate to an angular position in which outer transverse leg 75 of the tool head is oriented in an upright vertical disposition, as shown in FIG. 9 . In this position, a pickup tool 87 consisting of a cryoloop support cap 79 in which are installed a cryoloop pin 83 and cryoloop 85 is inserted downwards into socket 77 in the horizontally disposed, outer transverse end face 76 of tool head leg 75 . As shown in FIG. 9 , cryoloop pin 83 is then manually rotated about its longitudinal axis until the plane of the cryoloop is located in a generally fore-and-aft orientation, so that the loop plane is perpendicular to a cryogas stream issuing to the right from cryogas supply tube 183 .
After a cryoloop 85 has been installed in tool head 73 and oriented as described above, micropositioner position control knob 57 is manipulated by a human operator to move the tool head support arm and tool head upwards slightly to disengage or “undock” the tool arm from docking site 201 . This action causes electrical switch 202 to provide an open-circuit signal to electronic control circuitry 99 . Then, when the tool arm is moved downwardly a predetermined distance in response to manual operation of the position control knob 57 , downward motion of the follower mechanism causes a flag 204 thereon to interrupt a light beam from a LED of a photo sensor 203 fixed to the machine support structure. In response to a signal from photo sensor 203 , electronic control circuitry 99 outputs an electrical command signal to stepper motor 71 to orbitally rotate crank yoke 101 and attached tool head support arm 63 , clockwise from the vertically upright central docking orientation shown in FIG. 9 , to a laterally rightward and downward location, at which tool head 73 and cryoloop 85 are angled downwardly and towards the left, i.e., towards the center of the machine.
Then, as shown in FIGS. 1 , 3 , 5 , and 23 , position control knob 57 of micropositioner apparatus 32 is manipulated to move tool head 73 down towards work platform 37 and above a selected well of a plurality of wells 176 in the upper surface 177 of crystal growth plate 178 supported on the upper surface of the work platform. In this position, the human operator twists tool angle control knob 92 to pivot tool head 73 to that angular position which orients cryoloop 85 at an optimum inclination angle for harvesting a liquid drop and crystal from a crystal growth well 177 . The operator may then actuate Tool Angle Save switch 101 to store the selected tool angle.
With the inclination angle of the cryoloop 85 adjusted as described above, the human operator may then view the cryoloop 85 in relation to a selected crystal growth well 176 through stereo microscope 150 , and manipulate micropositioner position control knob 57 to cause the cryoloop to move obliquely downwards into the well, thus capturing a liquid drop holding a selected crystal within the cryoloop.
Position control knob 57 is then manipulated to thus move tool head support arm 63 , tool head 73 and cryoloop 85 holding a liquid drop containing a crystal to an upward position. Upward motion of tool head support arm 63 a predetermined distance causes an electrical signal produced by electrical sensor 203 consisting of a flag 204 and a photo transistor-LED arrangement 205 to command stepper motor 71 to orbit support arm 63 to an upper, leftward location towards the center of the machine. At this orbital position of tool arm 63 , tool head 73 and cryoloop 85 are oriented in an upright, generally vertical crystal retrieval position, as shown in FIGS. 11 , 14 and 25 .
Position control knob 57 is once again manipulated to thus move tool head support arm a short distance upwards and to the left, and then downwards until perceptible contact is made between docking arm 200 and docking switch 202 , as shown in FIG. 26 . Actuation of docking switch 202 causes a command signal to be issued to stepper motor 71 to rotate counterclockwise, thereby causing pinion and sector gears to mesh and thus tilt tool head 73 about 2 degrees counterclockwise from an orientation of about one-degree clockwise from a generally vertical orientation shown in FIG. 25 , to the tilted position shown in FIGS. 12 , 15 and 27 . As has been described above, this action causes cryofreezer shield plate 192 to pivot clockwise, thus allowing unobstructed flow of cryogas from cryogas 183 onto cryoloop 85 held in tool head. Tool head 73 is held in this position to allow cryogas to freeze cryoloop 85 and the crystal-containing liquid drop held therein, for a period sufficient to freeze the loop, liquid drop and crystal. This time period is preset by an operator input to Freeze Time Duration digiswitch 89 and ranges typically from about 0.1 second to about 4 seconds or more.
Upon expiration of the preset freeze time period, electronic control circuitry 99 outputs a command signal to stepper motor 71 to pivot tool head 73 clockwise to an orientation of about one-degree clockwise from an upright vertical position, as shown in FIG. 25 , thus causing cryofreezer shield plate 192 to return to a flow-blocking position. Then, as shown in FIG. 25 , a cryoloop 85 and crystal-containing liquid drop frozen thereto may be removed from tool head 73 and placed in a cryogenic storage container. A new cryoloop 85 may then be inserted into tool head 73 , to enable repetition of a crystal harvesting cycle.
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A micro-manipulator machine for harvesting and cryofreezing crystals for cryogenic storage and subsequent analysis includes a micropositioner mechanism for converting motions manually input to a position control knob to fractionally-scaled motions of a follower mechanism which includes a tool head support arm and tool head that releasably holds a filamentary polymer cryoloop for immersion into a liquid crystal growth media and extraction of a liquid drop containing a selected crystal from the media. A first automatic actuator mechanism orbits the tool head support arm, tool head, cryoloop, liquid drop and harvested crystal from a harvesting location to a retrieval location when the micropositioner input control arm has been moved manually away from the crystal harvesting location by the operator after extracting a crystal drop, and a second automatic actuator mechanism pivots the toll head into a flowing stream of a cryogenic gas to freeze the liquid drop and crystal.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application No. 61/400,320 filed on Jul. 26, 2010 for “High kinetic energy penetrator shielding and high wear resistance materials fabricated with boron nitride nanotubes (BNNTs) and BNNT polymer composites.”
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms, as provided for by the terms of Contract NCC-1-02043 awarded by the National Aeronautics and Space Administration.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to impact and wear resistant material, and, more particularly to impact and wear resistant material fabricated with boron nitride nanotubes (BNNTs).
[0005] 2. Description of Related Art
[0006] Micrometeoroids develop very high kinetic energies as they travel through space and pose a significant hazard to spacecraft and astronauts. The velocities of the micrometeorites can reach 20 kilometers per second prior to impact on the lunar surface [Eagle Engineering Incorporated, “Lunar Base Environment Report”, Kennedy Space Center, July, 1989]. Therefore an improved protective system utilizing new materials is needed to effectively shield space vehicles and structures against high kinetic energy penetrators as well as to provide penetration resistant space suits. In addition, new lightweight, conformable body armor for protection against high kinetic energy penetrators such as bullets and shrapnel, whilst providing increased mobility, has been sought for accomplishing successful missions on the modern battlefield.
[0007] Some materials have been considered for protection against high-speed penetrating impacts. Both non-metallic and metallic materials are often used for the protection. The non-metallic protective materials include Aramid (Kevlar®), ultra high molecular weight polyethylene (Spectra®), Mylar®, Fiberglass, Nylon, Nomex®, or ceramic composite plates [W. J. Perciballi, U.S. Pat. No. 6,408,733]. Carbon nanotubes and their composites have been suggested well [K. Mylvaganam and L. C. Zhang, “Ballistic resistance capacity of carbon nanotubes,” Nanotechnology, 47, 475701 (2007)]. The metallic protective materials include titanium and steel. Some of these materials have been proven to be highly protective against the high kinetic energy penetrators [F. J. Stimler, “System Definition Study of Deployable Non-metallic Space Structures”, Goodyear Aerospace Corporation, Report No. GAC 19-1615; NASA Contract NAS8-35498, June 1984].
[0008] Materials manufactured from heavy inorganic materials (metals and ceramics) have been used to achieve materials for use in environments where wear-resistant qualities are required.
[0009] State-of-the-art polymeric protective materials such as Kevlar® and Spectra® show poor thermal stability. The metallic or ceramic protective materials are very heavy, resulting in increased launch costs for space applications. Due to weight restrictions, these materials cannot be used in new space vehicle/structure concepts such as inflatable habitats and solar sails. Body armor fabricated with these materials provides little comfort and greatly restricts the wearer's mobility; as a result its use is often limited primarily to body torso protection.
[0010] Although carbon nanotubes are useful in high temperature environments up to 400° C., they oxidize and burn at temperatures above 400° C. so alternate materials are sought for use in environments experiencing temperatures above 400° C. As shown in FIG. 5 , BNNT materials have significant advantages in such high-temperature environments.
[0011] In certain applications, heavy, inorganic metals are used to achieve high wear resistance. Such metals increase the weight and reduce the efficiency of the apparatus.
[0012] In recent years, anti-penetration materials have been more and more widely used for protective apparel, bullet-proof vests, and micrometeoroid and orbital debris protection layers for space suits as well as space vehicles and structures.
[0013] In order to maximize the protection ability of a material against high kinetic energy penetrators, the following two major material properties should be considered: (1) high hardness for rebounding and/or gross mechanical deformation of the penetrator; and (2) high toughness for effective energy absorption during the mechanical deformation (and heat) of the protecting materials.
[0014] It is a primary aim of the present invention to provide a lightweight high kinetic energy penetration protection material fabricated with boron nitride nanotubes (BNNTs) and BNNT composites to maximize the energy absorption in the course of mechanical deformation, and heat, of the protecting materials under an impact.
[0015] It is an object of the invention to provide a lightweight high kinetic energy penetrator protection material fabricated with high hardness particles, such as boron nitride based nanoparticles (BNP) and BNP composites, to maximize rebounding of the penetrator or for gross mechanical deformation of the penetrator.
[0016] It is an object of the invention to provide materials having high wear resistance, and thus prolonged usage time of such materials under harsh abrasive conditions, such as battlefields and space environments, by improving hardness and toughness through the use of boron nitride nanomaterials.
[0017] It is an object of the invention to provide a lightweight high kinetic energy penetrator protection material fabricated with carbon nanotubes (CNTs), graphites, graphene oxides and their composites to maximize the energy absorption via mechanical deformation (and heat) of the protective materials.
[0018] It is an object of the invention to provide lightweight, high wear resistance materials fabricated with boron nitride nanotubes (BNNTs), boron nitride based nanoparticles (BNPs), boron-carbon-nitride nanotube (B x C y N z nanotubes), carbon nanotubes (CNTs), graphites, and their composites to prolong the usage time at a severe abrasion condition.
[0019] It is an object of the invention to provide a lightweight, ultra hard and tough BNNT fiber/woven/non-woven composite mat for flexible armor.
[0020] It is an object of the invention to provide a lightweight, high kinetic energy penetrator protection material fabricated with boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNPs), boron-carbon-nitride nanotubes (B x C y N z nanotubes), carbon nanotubes (CNTs), graphites, graphene oxides, metal coated nanoinclusions, metal particles and their composites to minimize a locally concentrated heating damage via increasing thermal conductivity.
[0021] It is a further object of the invention to provide a lightweight, ultra hard and tough BNNT fiber/woven/non-woven composite mat for space suit layers and deployable space craft/space craft systems.
[0022] Finally, it is an object of the present invention to accomplish the foregoing objectives in a simple and cost effective manner.
[0023] The above and further objects, details and advantages of the invention will become apparent from the following detailed description, when read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
[0024] The present invention addresses these needs by providing a method for forming a method for manufacturing an impact resistant material by synthesizing a boron containing nanomaterial/polymer material from a boron containing nanomaterial and a matrix by controlled dispersion of the boron containing nanomaterial into the matrix. The synthesized material is then applied to an object to be protected from impact. The boron containing nanomaterial is boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNPs), boron-carbon-nitride nanotubes (B x C y N z nanotubes), carbon nanotubes (CNTs), graphites, graphene oxides, metal coated nanoinclusions, metal particles, or composites thereof. The matrix is preferably provided with additional hardness by adding cubic boron nitride nanoparticles (c-BNNP), boron carbides, silicon carbide, titanium alloys or zirconia. The shape of the boron containing nanomaterial is preferably nanotubes, nanosheets, nanoribbons, nanoparticles, nanorods, nanoplatelets, nanocages, nanosprings, or nanomultipods. The boron containing nanomaterial is preferably homogeneously dispersed into the matrix. The boron containing nanomaterial is preferably synthesized by in-situ polymerization under simultaneous shear and sonication. The matrix is preferably synthesized from a hydrogen containing polymer, a hydrogen containing monomer, or a combination thereof. Other alternatives for synthesis of the matrix are a boron containing polymer, a boron containing monomer, and a combination thereof; or a nitrogen containing polymer, a nitrogen containing monomer, and a combination thereof. The concentration of boron nitride in the matrix is preferably between 0% and 5% by weight and most preferably is 5% by weight. The boron containing nanomaterial may comprise boron, nitrogen, carbon and hydrogen. The synthesized material may be in the form of a fiber which may be incorporated into fabric. Further, the synthesized fiber may be incorporated into a mat. Additionally, a polymer, a ceramic, and a metal may be infused into the fibers. The matrix may be a polymer matrix or a ceramic matrix. A method for manufacturing a multi-layer impact resistant material includes synthesizing a first layer of boron containing nanomaterial/polymer material from a BNNT and a matrix by controlled dispersion of the boron containing nanomaterial into the matrix and synthesizing a second layer of boron containing nanomaterial/polymer material from a carbon nanotube (CNT) and a matrix by controlled dispersion of the boron containing nanomaterial into the matrix. A multi-layered composite film is formed from the synthesized first and second layers, infused with polyurethane (PU), polyimide, polyethylene, aromatic polyamide, epoxy, phenol formaldehyde, or polyester resins; and then the synthesized film is applied to an object to be protected from impact. Finally, the methods described herein provide, in addition to impact resistant materials, wear resistant materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] A more complete description of the subject matter of the present invention and the advantages thereof, can be achieved by reference to the following detailed description by which reference is made to the accompanying drawings in which:
[0026] FIGS. 1A through 1D show a schematic diagram of high kinetic energy penetrator protection materials made according to the present invention: (A) BNNT or cubic-Boron Nitride Nano Particle (c-BNNP) composite; (B) BNNT or c-BNNP composite and CNT or graphite composite multilayer; (C) BNNT fiber or BNNT woven or non-woven mat composite; (D) high hardness and high toughness multilayer composite;
[0027] FIGS. 2A through 2D show impact damaged images: (A) photo taken by a digital camera of a control sample and (B) optical microscope image of a control sample; (C) photo taken by a digital camera of a BNNT reinforced sample according to the present invention and (D) optical microscope image of a BNNT reinforced sample according to the present invention;
[0028] FIGS. 3A-3E show applications for anti-high kinetic energy penetrator protecting composites according to the present invention: (A) spacecraft, (B) space-habitat, (C) helmet, (D) body armor and (E) vehicle armor;
[0029] FIGS. 4A-4D show the present invention as used in applications requiring high wear resistance materials: (A) brake pad, (B) gears, (C) knee joint replacement prostheses and (D) protection pads; and
[0030] FIG. 5 shows a Thermogravimetric Analysis (TGA) of CNT and BNNT; and
[0031] FIG. 6 shows the results of a Nanoindentation Vickers Hardness Test of BNNT composites.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] The following detailed description is of the best presently contemplated mode of carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating general principles of embodiments of the invention. The embodiments of the invention and the various features and advantageous details thereof are more fully explained with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and set forth in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and the features of one embodiment may be employed with the other embodiments as the skilled artisan recognizes, even if not explicitly stated herein. Descriptions of well-known components and techniques may be omitted to avoid obscuring the invention. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those skilled in the art to practice the invention. Accordingly, the examples and embodiments set forth herein should not be construed as limiting the scope of the invention, which is defined by the appended claims. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings.
[0033] Recently a novel material, boron nitride nanotube (BNNT), has been developed, which possesses high strength-to-weight ratio, high temperature resistance (above 800° C. in air), piezoelectricity, and radiation shielding capabilities [A. Rubio et al, Phys. Rev. Lett. 49, 5081 (1994); N. G Chopra et al, Science, 269, 966 (1995)]. The superior mechanical (hardness and toughness) and thermal (stability and conductivity) properties of these BNNTs make them an ideal material to develop a novel lightweight and high performance anti-penetrator material. They also provide excellent wear properties because of their unique high hardness, aspect ratio, and toughness, especially at elevated temperatures up to 900° C. Recently, a new and conceptually simple method of producing extraordinarily long, highly crystalline BNNTs was demonstrated. M. W. Smith et al., US Patent Application Pub 2009/0117021, M. W. Smith et al, Nanotechnology, 20, 505604 (2009), Continuation-In-Part application Ser. No. 12/322,591 filed Feb. 4, 2009 for Apparatus for the Production of Boron Nitride Nanotubes and Continuation-In-Part application Ser. No. 12/387,703 filed May 6, 2009 for Boron Nitride Nanotube Fibrils and Yarns, all of which are incorporated herein by reference in their entireties, describe such materials. Co-pending U.S. patent application Ser. No. 13/068,329 filed May 9, 2011, entitled “Neutron and Ultraviolet Shielding Films Fabricated Using Boron Nitride Nanotubes and Boron Nitride Nanotube Polymer Composites”, describing the manufacture of radiation shielding films fabricated using boron nitride nanotubes and boron nitride nanotube polymer composites, and Co-pending U.S. patent application Ser. No. 12/278,866 filed Oct. 13, 2010, entitled “Energy Conversion Materials Fabricated with Boron Nitride Nanotubes (BNNTs) and BNNT Polymer composites”, describing actuators and sensors fabricated with boron nitride nanotubes (BNNTs) and BNNT polymer composites, are also incorporated herein by reference in their entireties. Effective toughening efficacy of using nanotubular inclusions has been reported (Nanotubular Toughening Inclusions, Park et al, U.S. patent application Ser. No. 13/032,045, filed 2011 (LAR 17088); C. Lovell, K. E. Wise, J.-W. Kim, P. T. Lillehei, J. S. Harrison, C. Park, “Thermodynamic Approach to Enhanced Dispersion and Physical Properties in a Carbon Nanotube/Polypeptide Nanocomposite” Polymer, 50, 1925 (2009) (see page 1931 left column))
[0034] First, a BNNT/polymer nanocomposite film was synthesized to evaluate its properties as an anti-penetrator material. A high temperature polyimide was synthesized from a diamine, 2,6-bis(3-aminophenoxy) benzonitrile ((β-CN)APB), and a dianhydride, pyromelliticdianhydride (PMDA), and used as a matrix for this invention. The concentrations of BNNTs in the polyimide were 0 and 5 wt %. A schematic of the BNNT/polymer nanocomposite structure is shown in FIG. 1 ( a ). The hardness of the BNNT/polymer nanocomposites was measured by a microindentation method and the thermal conductivity of the nanocomposites was measured with Netzsch 457 Laser Flash Apparatus (Table 1). The loading force, duration time and speed of the indentation were 500 gf (4.90 N), 10 seconds, and 10 μm/s, respectively. While the hardness of the pristine polyimide was 24.3±0.7 kgf/mm 2 (238±7 MPa), that of the 5% BNNT doped polyimide composite was 49.8±7.6 kgf/mm 2 (488±75 MPa), showing 104.9% increase. Cubic boron nitride nanoparticles (c-BNNP), the second hardest material (Knoop hardness of 45 GPa) following diamond (Knoop hardness of 100 GPa), with superior thermal and chemical stability, may be added into matrices to secure superior hardness. Other hard materials such as boron carbides, silicon carbide, titanium alloys and zirconia can also be used as fillers. The enhanced hardness of the composite material provides an effective protecting capability against high kinetic energy penetrators by rebounding and/or causing gross mechanical deformation of the penetrator. In addition, adding 5% BNNT into the polymer matrix increased thermal conductivity by about 140% (Table 1). The increased thermal conductivity helps to reduce locally concentrated heating damage from the impact of high kinetic energy penetrators. The increased thermal conductivity along with the high thermal stability (>800° C. in air) helps to reduce a locally concentrated heating damage from the impact of high kinetic energy penetrators. Lightweight high kinetic energy penetrator protection material fabricated with boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNPs), boron-carbon-nitride nanotube (B x C y N z nanotubes), carbon nanotubes (CNTs), graphites, graphene oxides, metal coated nanoinclusions, metal particles and their composites minimizes locally concentrated heating damage via increasing thermal conductivity.
[0000]
TABLE 1
Microindentation hardness and thermal conductivity of
pristine and BNNT reinforced polymer composite
Hardness
Thermal Conductivity
Sample
(kgf/mm 2 )
W/(m · K)
Pristine PI
24.3 ± 0.7
0.132 ± 0.004
BNNT reinforced PI
49.8 ± 7.6
0.319 ± 0.029
(104.9% increase)
(140% increase)
[0035] A multi-layered composite film was fabricated using BNNT and carbon nanotube (CNT) layers infused with polyurethane (PU) resin as shown in FIG. 1 ( b ). Table 2 shows the mechanical properties of the multi-layered composite film prepared. The elastic modulus of the pristine PU was only 60.9 MPa, but that of the multi-layered composite was 756.9 MPa, showing increase of 1143.8%. The increased modulus of the BNNT/CNT composite promises the increase of toughness before fracture, which is another critical property for the anti-penetrator protection in addition to the high hardness.
[0000]
TABLE 2
Mechanical properties of pristine and BNNT reinforced polymer composite
Young's
Maximum
Tensile Stress
Tensile
Modulus
Tensile
at Break
Strain at
Sample
(MPa)
Stress (MPa)
(MPa)
Break (%)
Pristine PU
60.9
17.7
17.7
338.7
BNNT
756.9
14.7
13.0
3.2
reinforced PU
(1143.8%
multilayer
increase)
[0036] BNNT fibers or BNNT woven or non-woven mats can be used for the protection layer. Infusing a polymer, ceramic, or metal into the BNNT fibers or mats can increase the mechanical strength further ( FIG. 1 ( c )). A multi-layered composite containing both high hardness and high toughness layers can greatly enhance the anti-penetration protection and increase the wear resistance. A schematic of a multi-layered composite is shown in FIG. 1 ( d ). The top high hardness layer consisting of BNNT, c-BNNP or other high hardness materials provides initial protection against penetrators by bouncing or deforming them. The combination of various toughened layers such as a Kevlar® fabric (mat), BNNT reinforced Kevlar® woven or non-woven mat, BNNT or CNT composite layer offers superior toughness enabling effective absorption of the impact energy. High temperature resistance of the BNNT fibers/woven/non-woven mats (>800° C.) as well as their high thermal conductivity can further improve the anti-penetrator protection capability by dissipating thermal energy or heat very effectively without causing any loss of structural integrity. The high wear resistance can provide a durability of this protection material in harsh environments.
[0037] FIG. 2 shows an experimental result of an impact test by a potential energy method. All the target materials were pristine polyimide films. To observe the impact damage alleviation with BNNT composite, two different cover films for the targets were prepared: A control target specimen (pristine polyimide) was covered with two additional pristine polyimide films ( FIGS. 2 ( a ) and ( b )). To study the BNNT reinforcing effect, the other pristine polyimide target film was covered with a 2% BNNT/polyimide composite film and BNNT/CNT multi-layer film ( FIGS. 2 ( c ) and ( d )). The impact energy was 1.5 J for the BNNT reinforced film, corresponding to 0.27% of the US National Institute of Justice ballistic and slab documents (NIJ Standard-01101.06) type II protection limit energy (9 mm Parabellum Full Metal jacketed Round Nose (FMJ RN) bullet (8 g) at a velocity of 373 m/s). After impact, the cover films were removed, and images of each pristine and target film were taken. As shown in FIG. 2 , the control target created sharp and deep impact damage marks ( FIG. 2 ( a )). On the other hand, the BNNT reinforced target generated wrinkled and shallow impact damage marks ( FIG. 2 ( c )). Optical microscopy images ( FIGS. 2 ( b ) and ( d )) showed a clear difference between the impact damages of the control target and the BNNT reinforced target. As also shown in FIG. 6 , the BNNT reinforced target showed more wrinkled damage surface indicating that more energy was absorbed at the moment of impact.
[0038] FIG. 3 shows possible applications of the present invention. BNNT reinforced composite can be used for anti-high kinetic energy penetrator layer for spacecraft and space-habitat ( FIGS. 3 ( a ) and ( b )). Its possible uses include military and police applications such as helmets/shields, body armors and vehicle armors ( FIG. 3 ( c )-( e )).
[0039] In addition, the enhanced hardness and toughness using boron nitride nanomaterials promise high wear resistance. Thus, the enhanced wear resistance helps to prolong the usage time of anti-penetration material under harsh abrasive conditions, such as battlefields.
[0040] This material is an improvement for environments requiring a material having high wear-resistance characteristics for mechanical use such as brake pads, gears, vehicle tires, microelectromechanical system (MEMS) components, medical use such as dental restorative materials, prostheses and/or replacement joints, and entertainment/sports uses such as protection pads ( FIG. 4 ( a )-( d )). The BN and BNNT materials also offer transparent armor/shields and transparent wear resistance coatings and materials.
[0041] 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. Many improvements, modifications, and additions will be apparent to the skilled artisan without departing from the spirit and scope of the present invention as described herein and defined in the following claims.
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Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nanotubes (CNTs), graphites, or combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mats of BNNTs are used as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also used as reinforcing inclusions combining with other polymer matrices to create composite layers like typical reinforcing fibers such as Kevlar®, Spectra®, ceramics and metals. Enhanced wear resistance and usage time are achieved by adding boron nitride nanomaterials, increasing hardness and toughness. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800° C. in air. Boron nitride based composites are useful as strong structural materials for anti-micrometeorite layers for spacecraft and space suits, ultra strong tethers, protective gear, vehicles, helmets, shields and safety suits/helmets for industry.
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RELATED APPLICATIONS
[0001] This application is related to another application, entitled MEDICAL FLUID ACCESS DEVICE, Attorney Docket 112713-1206, U.S. patent application Ser. No. ______, which is filed on the same day as the present application, and assigned to the assignee of the present application, the entire contents of which are hereby incorporated by reference. This application is also related to U.S. patent application Ser. No. 11/458,816, filed Jul. 20, 2006, now U.S. Pat. No. ______, entitled Medical Fluid Access Site With Antiseptic Indicator, and U.S. patent application Ser. No. 11/550,643, filed Oct. 18, 2006, of the same title, now U.S. Pat. No. ______, entitled ______, both of which are incorporated by reference in their entirety.
BACKGROUND
[0002] The present disclosure relates generally to methods of immobilizing dyes and antimicrobial agents on a surface, especially a surface of a medical device. In particular, the disclosure relates to methods of treating a polymer surface for better attachment of antimicrobial agents onto the surface, and for the attachment of dyes to the surface. The dyes will change from a first color or appearance to a second color or appearance when they are swabbed with a disinfecting fluid, such as isopropyl alcohol (IPA) or a solution of water and IPA, especially a solution of 70% water/30% IPA.
[0003] Polymers are used in many medical devices in the health care industry. These polymers are used to make devices for therapeutic and for diagnostic purposes. For example, connectors for kidney dialysis, such as peritoneal dialysis and hemo-dialysis may be made of polymers. Dialysate fluid containers, access ports, pigtail connectors, spikes, and so forth, are all made from plastics or elastomers. Therapeutic devices such as catheters, drug vial spikes, vascular access devices such as luer access devices, prosthetics, and infusion pumps, are made from polymers. Medical fluid access devices are commonly used in association with medical fluid containers and medical fluid flow systems that are connected to patients or other subjects undergoing diagnostic, therapeutic or other medical procedures. Other diagnostic devices made from polymers, or with significant polymer content meant for contact with tissues of a patient, include stethoscopes, endoscopes, bronchoscopes, and the like. It is important that these devices be sterile when they are to be used in intimate contact with a patient.
[0004] Typical of these devices is a vascular access device that allows for the introduction of medication, antibiotics, chemotherapeutic agents, or a myriad of other fluids, to a previously established IV fluid flow system. Alternatively, the access device may be used for withdrawing fluid from the subject for testing or other purposes. The presence of one or more access devices in the IV tubing sets eliminates the need for phlebotomizing the subject repeatedly and allows for immediate administration of medication or other fluids directly into the subject.
[0005] Several different types of access devices are well known in the medical field. Although varying in the details of their construction, these devices usually include an access site for introduction or withdrawal of medical fluids through the access device. For instance, such devices can include a housing that defines an access opening for the introduction or withdrawal of medical fluids through the housing, and a resilient valve member or gland that normally closes the access site. Beyond those common features, the design of access sites varies considerably. For example, the valve member may be a solid rubber or latex septum or be made of other elastomeric material that is pierceable by a needle, so that fluid can be injected into or withdrawn from the access device. Alternatively, the valve member may comprise a septum or the like with a preformed but normally closed aperture or slit that is adapted to receive a specially designed blunt cannula therethrough. Other types of access devices are designed for use with connecting apparatus employing standard male luers. Such an access device is commonly referred to as a “luer access device” or “luer-activated device,” or “LAD.” LADS of various forms or designs are illustrated in U.S. Pat. Nos. 6,682,509, 6,669,681, 6,039,302, 5,782,816, 5,730,418, 5,360,413, and 5,242,432, and U.S. Patent Application Publications Nos. 2003/0208165 and 2003/0141477, all of which are hereby incorporated by reference herein.
[0006] Before an access device is actually used to introduce or withdraw liquid from a container or a medical fluid flow system or other structure or system, good medical practice dictates that the access site and surrounding area be contacted, usually by wiping or swabbing, with a disinfectant or sterilizing agent such as isopropyl alcohol or the like to reduce the potential for contaminating the fluid flow path and harming the patient. It will be appreciated that a medical fluid flow system, such as an IV administration set, provides a direct avenue into a patient's vascular system. Without proper aseptic techniques by the physician, nurse or other clinician, microbes, bacteria or other pathogens found on the surface of the access device could be introduced into the IV tubing and thus into the patient when fluid is introduced into or withdrawn through the access device. Accordingly, care is required to assure that proper aseptic techniques are used by the healthcare practitioner. This warning applies to many medical devices, especially those in contact with the patient, and especially so for access devices, which like catheters or infusion pumps, access the patient's bodily orifices, especially those of the vascular system.
[0007] As described more fully below, the methods for attaching antimicrobial agents and dyes that indicate that proper aseptic techniques have been used, are believed to represent important advances in the safe and efficient administration of health care to patients.
SUMMARY
[0008] One embodiment is a method of coating a surface. The method includes steps of providing a medical device having a porous polymer surface, cleaning the surface of the medical device, providing a plurality of functional groups on the surface, attaching a linking group to the functional group, and attaching a solvatochromic dye or a derivative of the solvatochromic dye to the functional group or to the linking group.
[0009] Another embodiment is a method of coating a surface. The method includes steps of cleaning a porous surface of a medical device made from a polymer, treating the surface with a strong acid to provide a plurality of functional groups on the surface, reacting the functional groups with a linking agent to form attachment sites, the linking agent selected from the group consisting of poly(N-succinimidyl acrylate) (PNSA) and polymers with an aldehyde functional group, and attaching a solvatochromic dye, an antimicrobial agent, or an alkyl-amino containing compound selected from the group consisting of peptides, proteins, Factor VIII or other anti-clotting Factor, polysaccharides, polymyxins, hyaluronic acid, heparin, chitosan, condroitin sulfate, and derivatives of each of these, to the attachment sites.
[0010] Another embodiment is a polymeric medical device. The polymeric medical device includes a housing of the polymeric medical device, a porous polymer surface atop the medical device, a plurality of attachment sites on the porous upper polymer surface, optionally, a plurality of functional groups attached to the attachment sites, and also includes at least one of: i. a solvatochromic dye or a derivative of the solvatochromic dye; and ii. an antimicrobial compound, attached to the attachment sites or to the functional groups, wherein the porous polymeric surface is configured to reversibly change from a first appearance to a second appearance when the surface is swabbed with a disinfecting solution.
[0011] Another embodiment is a medical device. The medical device includes a medical device having a porous surface made from a polymer, a plurality of attachment sites on the surface of the medical device, optionally, a plurality of functional groups attached to the attachment sites, and an antimicrobial compound, attached to the attachment sites or to the functional groups, wherein the antimicrobial compound is configured to be cidal to, or to resist growth of, microorganisms on the surface of the device.
[0012] Another embodiment is a medical device. The medical device includes a medical device having a porous surface made from a polymer, a plurality of attachment sites on the surface of the medical device, optionally, a plurality of functional groups attached to the attachment sites, and an alkyl-amino containing compound selected from the group consisting of peptides, proteins, Factor VIII or other anti-clotting Factor, polysaccharides, polymyxins, hyaluronic acid, heparin, chitosan, and derivatives of each of these, to the attachment sites.
[0013] Another embodiment is a dye. The dye includes a compound having a structure:
[0000]
[0014] and derivatives thereof, wherein R1 is acryloyl, methacryloyl, or hydrogen, R2 is C4 to C10 alkyl, R3 is ethene, R4 and R6 are bromide, chloride, fluoride, iodide, and mixtures thereof, R5 is one of hydrogen or O − , and R7 is the other of hydrogen and O − .
[0015] Another embodiment is a dye. The dye includes a compound having a structure:
[0000]
[0016] and derivatives thereof, wherein R1 is acryloyl, methacryloyl, hydrogen, halogen, alkoxy, alkyl mercapto, or an aromatic mercaptan, R2 is C4 to C10 alkyl, R3 is ethene, butadiene, or hexatriene, R4 and R6 are bromide, chloride, fluoride, iodide, alkoxy, nitrate, and mixtures thereof, R5 is one of hydrogen or O − , and R7 is the other of hydrogen and O − .
[0017] Another embodiment is a process for making a dye. The process includes steps of reacting a t-butyl-oxycarbonyl (BOC) amino aliphatic alcohol with a sulfonyl halide to yield a BOC-amino-aliphatic-sulfonate, reacting the BOC-amino-aliphatic-sulfonate with 4-picoline to form a pyridinium sulfonate, and reacting the pyridinium sulfonate with a substituted salicylaldehyde compound to form a compound with a merocyanine dye functionality, wherein the merocyanine dye has the general structure of
[0000]
[0018] wherein R′=t-butyl-oxycarbonyl, n=1, 2, or 3, X=bromide, chloride, fluoride, iodide, alkoxy, nitrate, and mixtures thereof and are both in meta positions, and wherein the O − is in an ortho or para position.
[0019] Another embodiment is a process for making a dye. The process includes steps of forming a BOC-amino-aliphatic-sulfonate from a primary alcohol and a sulfonyl halide, reacting the BOC-amino-aliphatic-sulfonate with 4-picoline to form a pyridium sulfonate, reacting the pyridinium sulfonate with a substituted salicylaldehye to form a phenolate with a monomerocyanine functionality, and dissolving the phenolate in an acid to form a first salt.
[0020] Additional features and advantages are described herein, and will be apparent from, the following Detailed Description and the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0021] FIG. 1 is a perspective view of a medical device; and
[0022] FIG. 2 is a cross-sectional view of a medical device.
DETAILED DESCRIPTION
Synthesis of Solvatochromic Dye Useful as an Antiseptic Indicator
[0023] The synthesis of a solvatochromic dye that has been found useful as an antiseptic indicator is herein described. The synthesis was carried out in five distinct steps. A first step reacts 6-t-butyloxycarbonyl-amino-1-hexanol (also known as 6-(BOC-amino)-1-hexanol), compound (1) below, from Sigma Aldrich, St. Louis. Mo., U.S.A., with p-toluenesulfonyl chloride, compound (2) below, to yield 6-(BOC-amino)hexyl-p-toluenesulfonate, compound (3) below.
[0000]
[0024] The second step substituted 4-picoline, compound (4) below, for the p-toluene sulfonate portion, resulting in 1-(6-BOC-aminohexyl)-4-methylpyridinium monotosylate, compound (5) below.
[0000]
[0025] For the third step, 1-(6-BOC-amino)hexyl-4-methylpyridinium was condensed with 3,5-dicholoro-salicylaldehyde, compound 6, in the presence of piperidine, resulting in the formation of 4,6-dichloro-2-[2-(6-BOC-amino)hexyl-4-pyridinio)vinyl]phenolate, compound 7 below.
[0000]
[0026] The fourth step then removed the BOC portion by reacting compound 7 with trifluoroacetic acid to yield 4,6-dichloro-2-[2-((6-amino)hexyl-4-pyridinio)-vinyl]phenolate di(trifluoroacetate) salt, compound 8.
[0000]
[0027] The final step included two parts, the addition of excess acryloyl chloride, compound 9, to form compound 10. This part was followed by hydrolysis of the acryloyl moiety with ammonium hydroxide, which resulted in the dye, compound 11.
[0000]
DETAILED DESCRIPTION OF INDIVIDUAL STEPS
[0028] 6-t-butyloxycarbonyl-amino-1-hexanol (also known as (BOC-amino)-1-hexanol), compound (1) above, 34.45 grams (hereinafter abbreviated as “g.”), was dissolved in 300 ml chloroform and the solution cooled to about 5° C. in an ice bath while under an argon purge. Triethylamine, 44.2 g. was added and the solution stirred for about 15 minutes. p-Toluene sulfonyl chloride, compound 2, 36.28 g., was added to the solution and the reaction flask was removed from the ice bath and continually stirred for about 4 hours at room temperature. The solution was then concentrated to a clear, slightly yellow oil by rotary evaporation at 30° C. and was azeotroped with 2 sequential extractions with 100 ml chloroform to yield a semi-solid product. The crude product was taken up in 500 ml of a 1:1 mixture of ethyl acetate and hexane, which caused the precipitation of a triethylamine HCl salt, which was removed by filtration. The filter cake was rinsed with 3 sequential rinses of about 75 ml ethyl acetate, which was combined with the filtrate. The filtrate was concentrated to an oil by rotary evaporation at 30° C., yielding about 75 g, and was diluted in 75 ml chloroform. This was purified by flash column chromatography (silica gel) employing a mobile phase solution of hexane: ethyl acetate (5:1 through 1:1). Isolated fractions were then combined and concentrated to yield a white, cloudy oil product, 6-(BOC-amino)hexyl-p-toluenesulfonate, 56.59 g., compound 3 above. The structure was verified with NMR and the mass spectrum (ESI+) peak of 394.2 m/z [M+Na] + is consistent with the sodium salt adduct.
[0029] 55.63 g. of compound 3 was diluted in 400 ml isopropyl alcohol and 15.4 g. 4-picoline, compound 4 was added while stirring in an argon purge. The reaction solution was heated to reflux and continued for 21 hours reaction time. The solution was then concentrated to a clear, slightly amber-colored oil, 77.64 g. The crude oil product was then diluted in 75 ml chloroform and purified by flash column photography (silica gel) employing a chloroform:methanol (20:1 through 1:1) mobile phase solution. Three sets of isolated fractions were combined and concentrated by rotary evaporation at 30° C.
[0030] The first set was a clear yellow oil, 7.57 g., which was relatively impure. The third set was a pure off-white paste, 11.72 g., of 1-(6-BOC-amino)-hexyl)-4-methyl-pyridinium monotosylate, compound (5). The second set was a relatively pure, clear, slightly yellow oil, 45.11 g., which was further purified as follows. It was diluted in 250 ml chloroform, and upon sitting for a few minutes, clear and colorless floating crystals of p-toluenesulfonic acid formed, which were removed by filtration. The filtrate was extracted with three sequential washes of 100 ml distilled water, and the organic layer was then concentrated by rotary evaporation at 30° C. to a clear, slightly yellow oil, yielding 36.88 g. of compound 5. The structure was verified by NMR (nuclear magnetic resonance), and had a mass spectrum (ESI+) with m/z 293.2 [M] + , which is consistent with the pyridinium portion of the monotosylate salt that is compound 5.
[0031] Compound 5, 46.60 g., was then diluted in 500 ml ethanol and 15.0 ml piperidine was added, followed by 19.16 g. 3,5-dicholorosalicylaldehyde, compound 6. The reaction solution was brought to reflux while stirring under a continuous argon purge. After reacting overnight, the solution was concentrated to a dark purple semi-solid by rotary evaporation at 30° C. This was then dissolved in 200 ml ethanol and distilled water was added drop-wise with rapid stirring. After stirring overnight, the solid, which included both fine and agglomerated particles, was collected. The solid was recrystallized a second time in the same manner. After stirring for 2 hours, a fine orange/red precipitate was collected by filtration. When the filter cake was rinsed with 250 ml distilled water, it immediately turned an olive-green color. The solid was dried overnight at room temperature under a high vacuum. The solid was then recrystallized a third time in the same manner. After stirring for two hours, a fine orange/red precipitate was collected by filtration. The filter cake was rinsed with four sequential washes of 250 ml of a 7:1 mixture of distilled water:ethanol. The solid product was dried at 80° C. at a pressure of about 1 mm Hg for 39 hours, yielding a 36.37 g. of a dark purple solid product, compound 7. The structure was verified by NMR and the mass spectrum (ESI+) m/z of 465.2 [M+H] + was consistent with 4,6-dichloro-2-[2-((6-BOC-amino)hexyl-4-pyridinio)vinyl]phenolate.
[0032] 10.02 g. of compound 7 was then dissolved in a 1:1 mixture of 100 ml of trifluoroacetic acid and chloroform, and the reaction solution was continuously stirred at room temperature. After 4.5 hours, the reaction was complete and the solution was concentrated to a clear, amber-colored oil. The oil was azeotroped with 3 successive 100 ml aliquots of chloroform, followed by three successive 150 ml aliquots of ethyl acetate, yielding a bright yellow solid product. This product was then taken up in 150 ml ethyl acetate, vigorously shaken, and the fine yellow solid product collected by filtration. The filter cake was rinsed with three successive 25 ml measures of ethyl acetate, and was dried at 50° C. at a pressure of about 1 mm Hg for four hours. The result was 10.73 g. of a bright yellow solid product, 4,6-dichloro-2-[2-((6-amino)hexyl-4-pyridinio)vinyl]phenolate di-(trifluoroacetate) salt, compound 8. The structure was verified by NMR and the mass spectrum (ESI+) m/z of 365.1 [M] + , and 183.1 [M+H] 2+ , was consistent with the cationic moiety of compound 8.
[0033] This product, 7.07 g., was then dissolved in 200 ml of dimethyl formamide, to which was added a 5 ml solution of 2,6-di-tert-butyl 4-methylphenol, 9.27 mg/ml in 71.1 ml DMF. 10 ml triethylamine was then added, causing the solution to become dark purple. The solution was then cooled to about 5° C., while stirring under an argon purge. Acryloyl chloride, compound 9, in an amount of 3.37 ml in 25 ml chloroform was added dropwise to the solution over a period of about 15 minutes, causing the solution to become clear and light brown in color. After complete addition, the reaction solution was evaluated by thin layer chromatography (TLC) using silica gel F 254 plates and a chloroform:methanol 2:1 mobile phase. A small amount of acryloyl chloride, about 0.24 ml, was added to the reaction solution and the solution reevaluated later by TLC. The result is believed to be product 10, the chloride salt of 1-acryloyl-4,6-dichloro-2-[2-(1-acrylamidohexyl-4-pyridinio)vinyl]phenolate.
[0034] Compound 10 was treated with 15 ml ammonium hydroxide to form the final product. After treatment, 2 L ethyl ether was added to the product with rapid stirring, causing a dark-purple, viscous solid to form. Dark-purple supernatant was decanted from the viscous solid, which was then taken up in 1 L ethyl ether, from which a clear and colorless supernatant was decanted. The solid was mostly dissolved in 100 ml ethanol and 1 L ethyl ether was added to it with rapid stirring. After about 30 minutes, a brownish-purple solid was collected by filtration, and the filter cake was rinsed with ethyl ether. It was then dried under high vacuum for about 2 hours. The product was then purified by flash column chromatography using a 10:1 through 1:1 chloroform:methanol mobile phase solution. Isolated fractions were then combined and concentrated to yield a yellow/orange colored dye. This was then washed with ethyl ether, collected by filtration, and dried under high vacuum overnight, yielding a yellow solid. The solid was dissolved in 150 mL of methanol and 1.5 L of ethyl ether was slowly added with rapid stirring. After 30 minutes, a light green precipitate was collected by filtration and was rinsed with two successive portions of 100 mL ethyl ether. It was dried under high vacuum overnight, yielding 1.085 g. of a light, greenish-yellow solid compound, 11. The structure of compound 11 was verified by NMR and the mass spectrum (ESI+) m/z peak of 419 [M+H] + was consistent with compound 11.
[0035] This product, however, did not enjoy solvatochromic activity. It is believed that this was due to stacking and layering of molecules in a tight formation caused by ionic and hydrophobic interactions between adjacent molecules and portions thereof. The product was therefore made basic to restore its dye activity.
[0036] The product was then made basic by dissolving 0.8 g. of compound 11 in 20 ml methanol, to which was added 2.00 ml of 1 M NaOH, causing the product to dissolve and form a dark purple color. After stirring for 10 minutes, the solution was concentrated by rotary evaporation at 30° C. to a dark solid. This was redissolved in 20 ml methanol and re-concentrated. It was then azeotroped in three successive aliquots of 25 ml chloroform. The resultant product was then recrystallized by dissolving in 5 ml methanol and adding 100 ml ethyl ether dropwise, while stirring. After about 30 minutes, a fine dark, purple colored solid product precipitated out of solution. This was collected by filtration, washed with ethyl ether, and dried under high vacuum for 11 hours. The result, 0.81 g. of a fine, dark brownish purple solid, was obtained. Other bases may also be used, including at least the hydroxyl compounds of alkali metals, alkaline earths, and ammonium, i.e., potassium hydroxide, calcium hydroxide, ammonium hydroxide, and virtually any other strong hydroxide basic compound.
[0037] The result, 4,6-dichloro-2-[2-(1-acrylamidohexyl-4-pyridinio)vinyl]-phenolate, was dissolved in radical polymerizable acrylated resin, discussed elsewhere in this application, in concentrations ranging from 0.1% to 0.5%. The resin was then cured by UV irradiation of 320-350 nm at doses ranging from 0.8 J/cm 2 to 1.8 J/cm 2 . The result was a solvatochromic film with a bluish-purplish color. When wiped with isopropyl alcohol, the film turned pink, and then returned to a blue color after drying.
[0038] While the above description is accurate, it is clear that many modifications may be made to the process and to the end products achieved. For instance, while sodium hydroxide was used to achieve a solvatochromic dye, other bases may also be used for the same purpose, at least the monovalent ones, such as potassium or sodium. Divalent bases, such as calcium or magnesium hydroxide, are also appropriate and work well. It is believed that the more important aspect of making the dye basic is the separation of the molecular layers, rather than the particular cation and base used, e.g., NaOH, NH 4 OH, KOH, Mg(OH) 2 , Ca(OH) 2 , Ba(OH) 2 , and so forth, especially bases made with the alkali and alkaline earth metals.
[0039] Without being bound to any particular theory, the solvatochromic activity is believed to be due at least in part, to the portion of the molecule between the phenolate ring and the pyridine ring. Accordingly, it has been found that substitution of a hydrogen atom for the acrylamido group does not adversely affect the solvatochromic activity of the dye. The structure of the this molecule, 4,6-dichloro-2-[2-(6-aminohexyl-4-pyridinio)vinyl]phenolate compound 12, is shown below, and is compound 8 discussed above, after neutralization and removal of the trifluoroacetate counterions. In one sense, compound 12 below is compound 11 with a hydrogen substituting for the acryl group.
[0000]
[0040] Compound 12 is more easily handled as a salt, which may be the HCl, HBr, HF, phosphate, sulfate, and many others, so long as the species is not carboxylated. In order to make this substance, the compound #8 above is neutralized with a mixture of HCl/dioxane (available from Aldrich) or HCl dissolved in other compatible organic solvent, such as chloroform.
[0041] The same compound, with a methacrylamido group, equally activating or electron-withdrawing, is also suitable and may be achieved using methacryloyl chloride in the step for the conversion of compound 8 above. Other substitutes, R1, on the amine group nitrogen atom include at least the halogens, chloride, bromide, fluoride, iodide, and alkyl mercapto. Alkyl mercapto groups, such as ethyl mercapto, and non-bending aromatic bridge groups, such as aromatic mercaptan, are also suitable. It is also possible that at least short chain alkoxy derivatives, such as C3 through C6, especially C3 and C6, are suitable. A hexyl group between the amine group and the pyridine ring worked well. Other short chain aliphatic molecules may also be used in these solvatochromic dyes, such as isohexyl, pentyl, isopentyl, butyl, isobutyl, and decyl and many others, up to C 20 , i.e., C 4 to C 20 aliphatic. It is also believed that aliphatic species are required. Other molecules that will perform well as a solvatochromic dye include substitution of ethene group between the pyridine ring and the benzene ring by conjugated double bonds of butadiene, —C═C—C═C— or hexatriene, —C′C—C═C—C═C—. Other embodiments may include substitutions on the benzene ring, as shown below in structure 13. Either or both of the chlorides at R4, R6, may be replaced by iodide, bromide, or fluoride. The O − group in the 1-position could instead be placed in the 5-position between the chlorides. It is possible that nitrate, —NO 2 , alkoxy, such as methoxy, ethoxy, may also yield a solvatochromic dye. Note that a number of substations on the benzene ring are readily available. For example, several salicylaldehyde compounds with halogen atoms in the 3, 5 positions are readily available from manufactures, such as Sigma-Aldrich, St. Louis, Mo., USA. When the salicylaldehyde molecule reacts with its aldehyde functionality to the pyridine ring on structure 5, the 3, 5 positions on the salicylaldehyde molecule become the 4, 6 positions on the phenol/phenolate product formed. Of course, R1 may be amine or acrylamido, R2 is C4 to C20 aliphatic, R3 is ethene, butadiene, or hexatriene, R4 and R6 are as discussed above, and R5 may be one of hydrogen and O − and R7 may be the other of hydrogen and O − .
[0000]
[0042] It is possible to incorporate the dye into a coating, preferably a permeable coating, that may be applied to luer access device (LAD) housings. LAD housings are typically made from polycarbonate (PC), but they may also be made from elastomers and other plastics, such as acrylic (such as PMMA), acrylonitrile butadiene styrene (ABS), methyl acrylonitrile butadiene styrene (MABS), polypropylene (PP), cyclic olefin copolymer (COC), polyurethane (PU), polyvinyl chloride (PVC), nylon, and polyester including poly(ethylene terephthalate) (PET). There are many coatings that will firmly adhere to the above mentioned plastics, including epoxies, polyesters, and acrylics. An example of a medical device, a vascular access device, is seen in FIG. 1 . Luer access device 10 includes a housing 12 , male luer connector threads 14 , a rim 16 , and a septum 18 . Rim 16 is porous and includes a swab-access dye, shown as a dotted surface 16 a. Rim 16 and rim surface 16 a have been treated so that antimicrobial compounds and dyes will attach to surface 16 a.
[0043] Other embodiments are described in related application, MEDICAL FLUID ACCESS DEVICE, Attorney Docket 112713-1206, U.S. patent application Ser. No. ______, which is filed on the same day as the present application, and is assigned to the assignee of the present application, the entire contents of which are hereby incorporated by reference. Surface 16 a is porous or permeable and the polymer from which the surface is made preferably has an index of refraction from about 1.25 to about 1.6. The permeable surface is typically opaque and may incorporate a small amount of dye. The amount of the dye, such as from about 0.1% to about 1%, is effective in adding a color to the surface, or rendering the surface a translucent with a tint or hint of color.
[0044] The surface is porous, so that a disinfecting or antiseptic swabbing solution, such as IPA or a 70% IPA/30% water solution, will permeate the surface. The disinfecting solution may also contain an antimicrobial compound, such as chlorhexidine. If the index of refraction of the swabbing solution, about 1.34, matches or is close to the index of refraction of the polymer from which the porous surface is made, the surface will become transparent, if there is no dye. If a dye is present, the surface will change color as the dye changes state from a first pH to a second, different pH, the pH of the swabbing solution. Solutions or swabbing compounds other than IPA and water may be used, although theses are the most common. For example, ethanol has a refractive index of 1.36. Additions to the swabbing solution, such as chlorhexidine, will also vary the refractive index, thus allowing users to tailor the swabbing solution to insure a visually distinct appearance change, whether from opaque to transparent or from one color to another.
[0045] FIG. 2 depicts a medical device 20 with housing 22 and a porous surface layer 24 . The pores are shown as narrow channels 25 in the surface layer 24 . The porous surface layer may include effective amounts of the dye 26 , about 0.1 to about 1.0% by weight, and may also include small amounts of antimicrobial or oligodynamic compounds 28 . There are many ways to make compounds porous, e.g., by purchasing membranes with known pore size and density, by applying solvents in the well-known TIPS (thermal inversion phase separation) process, or by inducing surface crazing or cracking into the surface. Polycarbonate membranes with tailored pore sizes may be purchased from Osmonics Corp., Minnetonka, Minn., U.S.A., and polyethylene membranes may be purchased from DSM Solutech, Eindhoven, The Netherlands. Pore sizes may vary from 1 μm down, preferably 0.2 μm down. This small pore size, and smaller, is sufficient to allow permeability to antimicrobial swabbing solutions, but large enough to prevent access by many microorganisms, which tend to be larger than 0.2 μm diameter. Many of these techniques are described in the above-mentioned related patent applications, all of which were previously incorporated by reference.
Immobilization of Dyes and Microbial Agents on Polymer Surfaces
[0046] This section describes the experimental work that was done to prepare such surfaces for direct attachment of the dye molecules. The substances used to prepare the surfaces function by reacting the surfaces and adding functional groups that will bind the dye to the surface. Examples of dyes include Reichardt's dye and the solvatochromic dye described above. As also described above, the dye changes color to alert a medical professional that the surface, such as a luer access device (LAD) surface, has been swabbed and is momentarily clean. This technique is also effective in binding microbial agents to the surface. Examples include chlorhexidine compounds and derivatives, such as chlorhexidine gluconate, and other antimicrobial agents bearing aminoalkyl groups. Examples also include chloroxyphenol, triclosan, triclocarban, and their derivatives, and quaternary ammonium compounds. Many other antimicrobial or oligodynamic substances may also be attached. These compounds are cidal to, or at least to inhibit the growth of, harmful bacteria or other microorganisms on the surfaces to which they are applied, which is beneficial to the patient.
[0047] Materials known to have properties of resistance to such microorganisms are described and disclosed in U.S. Pat. No. 4,847,088, U.S. Pat. No. 6,663,877, and U.S. Pat. No. 6,776,824, all of which are hereby incorporated by reference in their entirety as though they were copied directly into this patent. For instance, quaternary ammonium compounds (frequently with organic or silicate side chains) are well-known for such properties, as are boric acid and many carboxylic acids, such as citric acid, benzoic acid, and maleic acid. Pyridinium and phosphonium salts may also be used. Besides organic compounds, certain non-organic materials and compounds are also known for their resistance to germs and organisms. Antimicrobial compounds are used in low concentrations, typically about from about 0.1% to 1% when incorporated into the material itself, e.g., a housing of a luer access device or other vascular access device. Antimicrobial compounds may also be used on many other medical devices, such as catheters, dialysis connects, such as those used in peritoneal dialysis, hemodialysis, or other types of dialysis treatment. They may also be applied to drug vial spikes, prosthetic devices, stethoscopes, endoscopes and similar diagnostic and therapeutic devices, and to infusion pumps and associated hardware and tubing. The use of antimicrobial compounds on these devices, among others, can help to prevent infection and to lessen the effect of infection.
[0048] Metals, especially heavy metals, and ionic compounds and salts of these metals, are known to be useful as antimicrobials even in very low concentrations or amounts. These substances are said to have an oligodynamic effect and are considered oligodynamic. The metals include silver, gold, zinc, copper, cerium, gallium, platinum, palladium, rhodium, iridium, ruthenium, osmium, bismuth, and others. Other metals with lower atomic weights also have an inhibiting or cidal effect on microorganisms in very low concentrations. These metals include aluminum, calcium, sodium, lithium, magnesium, potassium, and manganese, among others. For present purposes, all these metals are considered oligodynamic metals, and their compounds and ionic substances are oligodynamic substances. The metals and their compounds and ions, e.g., zinc oxide, silver acetate, silver nitrate, silver chloride, silver iodide, and many others, may inhibit the growth of microorganisms, such as bacteria, viruses, or fungi, or they may have cidal effects on microorganisms, such as bacteria, viruses, or fungi, in higher concentrations. Because many of these compounds and salts are soluble, they may easily be placed into a solution or a coating, which may then be used to coat a vascular access device, such as a luer access device. Silver has long been known to be an effective antimicrobial metal, and is now available in nanoparticle sizes, from companies such as Northern Nanotechnologies, Toronto, Ontario, Canada, and Purest Collids, Inc., Westampton, N.J., U.S.A. Other oligodynamic metals and compounds are also available from these companies.
[0049] Other materials, such as sulfanilamide and cephalosporins, are well-known for their resistance properties, including chlorhexidine and its derivatives, ethanol, benzyl alcohol, lysostaphin, benzoic acid analogs, lysine enzyme and metal salt, bacitracin, methicillin, cephalosporin, polymyxin, cefachlor, Cefadroxil, cefamandole nafate, cefazolin, cefime, cefinetazole, cefonioid, cefoperazone, ceforanide, cefotanme, cefotaxime, cefotetan, cefoxitin, cefpodoxime proxetil, ceftaxidime, ceftizomxime, ceftrixzone, cefriaxone moxolactam, cefuroxime, cephalexin, cephalosporin C, cephalosporin C sodium salt, cephalothin, cephalothin sodium salt, cephapirin, cephradine, cefuroximeaxetil, dihydracephaloghin, moxalactam, or loracarbef mafate. Microban, “Additive B,” 5-chloro-2-(2,4 dichloro-phenoxy)phenol is another such material.
Functional Groups
[0050] The following portion discusses a number of processes found to be effective in providing functional groups for the attachment of the above-mentioned solvatochromic dyes and antimicrobial agents. Functional groups may include an activated carboxy group, an activated amine group, or an activated amide group. The desired dye or agent may then be directly attached, or an intermediate group may be used attach the desired substance.
Nylon Surfaces
[0051] In one example, a Whatman nylon-6,6 membrane, pore size 0.2 μm, 47 mm, Whatman Cat. No. 7402-004, was obtained from Whatman Inc., Florham Park, N.J., USA. Other membranes are also available from Whatman, including other nylons or polyamides, polytetrafluoroethylene (PTFE or Teflon®), polyester, polycarbonate, cellulose and polypropylene. The membranes were first washed thoroughly, successively with dichloromethane, acetone, methanol and water. The membranes were then washed several times with water to achieve a neutral pH. They were finally washed in methanol and dried under high vacuum. The membranes were then treated with 3M HCl at 45° C. for four hours to yield specimen NM-1. Without being bound by any particular theory, it is believed that this resulted in the creation of a number of amino groups on the membrane surface. The free amine concentration of the untreated nylon was calculated as 6.37×10 −7 moles/cm 2 , while the free amine concentration after acid treatment was calculated as 13.28×10 −7 moles/cm 2 . The concentration was calculated using the method of Lin et al., described in Biotech Bioeng., vol. 83 (2), 168-173 (2003). Thus, the treatment appeared to double the concentration of free amine on the surface and available for binding.
[0052] The NM-1 membrane was then contacted with poly(N-succinimidyl acrylate) (PNSA) dissolved in dimethylformamide (DMF) by placing the membrane in a flask with the dissolved PNSA. It is expected that treatments with other polymers containing aldehyde groups, such as polyacrylaldehyde or polyacrolein, would also be effective. Triethanolamine was then added to the flask, which was rotary shaken while under a continuous argon purge for about 6 hours. The treated nylon membrane was then thoroughly washed with DMF to produce N-succinimidyl carboxylate groups on the surface of the nylon, forming NM-2. The di(trifluoroacetate) salt of 4,6-dichloro-2-[2-(6-amino-hexyl-4-pyridinio)-vinyl]phenolate was dissolved in DMF and was converted by neutralization of the trifluoroacetate counter ions with triethylamine. The previously-treated membrane was added to the reaction flask and was rotary-shaken overnight. The resulting membrane, NM-3, with the salt of 4,6-dichloro-2-[2-(6-amino-hexyl-4-pyridinio)-vinyl]phenolate on its surface, was then thoroughly washed with DMF. The surface of the membrane was a light purple when dry. The same surface turned dark purple when swabbed with isopropyl alcohol, and turned a salmon color when swabbed with a mixture of isopropyl alcohol containing about 30% water.
[0053] It is believed that the NM-3 membrane had excess N-succinimidyl carboxylate on its surface. It is also believed that this excess would hydrolyze and protonate the dye at the phenolate position, rendering the dye colorless. A number of NM-3 membranes were treated with different amines to stabilize the carboxy groups and also to discover what colors or other properties would result from the use of different amines. A series of membranes, NM-4 to NM-9 were treated with different amines, resulting in membranes with more stable surfaces but with only slightly different colors. The particular amine was dissolved in methanol, the membrane was added to the reaction flask, and the flask was rotary shaken overnight. The resulting membrane was then washed with acetone and dried under vacuum. Table 1 below summarizes the different used amines and the resulting properties. These results suggest that a number of amino and ammonium compounds may be used to provide attachment sites, including primary amines, ammonium hydroxide, amine (NH 2 )-terminated compounds and polymers, morpholine, and an aromatic primary amine.
[0054] The membranes had pores on the order of 0.2 μm, resulted in rapid color changes when swabbed, and returned to the dry color within a minute or two. As noted, it is believed that the NM-3 membrane had an excess of carboxylate groups on its surface. Therefore, an antimicrobial agent, chlorhexidine, was applied. Chlorhexidine was dissolved in methanol, the membrane was added to the reaction flask, and the flask was rotary shaken overnight. The membrane was thoroughly washed with acetone and dried under vacuum. It is believed that this membrane, NM-10, now contained both antimicrobial agent and dye. The membrane was tested. Its dry color was a moderate purple, turning to a dark purple in isopropyl alcohol (IPA) and to a moderate orange/red in 70% IPA.
[0000]
TABLE 1
Amine Treatment of Nylon Membranes
Nylon
Amine
Color,
Membrane-
dose,
reagent
Soln
Color,
IPA + 30%
Number
Amine used
mmol.
soln, ml
pH
Color, dry
IPA
water
NM-4
2-methoxyethylamine
15
7.50 ml
11.5
Very, very
Light
Light
DMF
light pink
brown/
brown/
pink
pink
NM-5
Hexylamine
15
7.50 ml
12
Very, very
Light
Light
DMF
light
brown/
brown/
brown/pink
pink
pink
NM-6
Benzylamine
15
7.50 ml
11.5
Very light
Light
Light
DMF
pink
brown/
brown/
pink
pink
NM-7
Morpholine*
15
7.50 ml
10
Moderate
Dark
Salmon
DMF
purple
purple
NM-8
Ammonium hyroxide
excess
20 ml
ND**
Moderate
Dark
Salmon
NH 4 OH
purple
purple
NM-9
3-aminopropyl-
3.51
10 ml
10
Light
Moderate
Moderate
terminated poly-
toluene
purple
purple
salmon
dimethylsiloxane
*NM-7 had an additional 0.1 ml triethylamine added, with a final pH of 11- to 11.5.
**The pH of the NM-8 solution was not determined.
Polycarbonate Surfaces
[0055] A second series of plastic surfaces was also tested. DE1-1D Makrofol® polycarbonate films, 0.005 inch thick, clear-gloss/gloss, were obtained from Bayer Polymers Division, Bayer Films Americas, Berlin, Conn., USA. The films were cut into 1 cm squares and were treated with 4 ml of a solution of 0.25 M chlorosulfonic acid in ethyl ether. The square and the solution were placed in a screw-cap vial and cooled to about 5° C. and rotary shaken for 1 hour. The resulting chlorosulfonated film was thoroughly washed with ethyl ether to yield membrane PC-1. It is believed that the amino end groups on the 4,6-dichloro-2-[2-(6-amino-hexyl-4-pyridinio)-vinyl]phenolate dye would react with the chlorosulfonyl groups which had been attached to the polycarbonate surface. A solution of the dye was prepared by dissolving 10 mmol in ethanol and treating with 0.22 mmol triethylamine. The resulting dye solution had a pH of 9.7. The PC-1 film was then added to a rotary flask containing the dye and was rotary shaken overnight and then washed thoroughly with methanol to yield film PC-2. The dry film had a moderately pinkish/purple color. When wetted with 70% IPA, it turned to a peach color.
[0056] Other films treated in the same manner, but with a four-hour chlorosulfonic acid treatment, had no color change activity. It is believed that the chlorosulfonyl moiety is a temporary transition product that converts to a more stable entity over time, and thus is not available for attachment of the dye. Other experiments included varying the time for dye attachment from 1 day to 5 days. The films treated for longer periods of time also had more intensely-colored surfaces. Due to the solubility of PC in other solvent, only ethyl ether was used for this experiment. The color change in the polycarbonate film, with very low porosity, was much slower than the color change in membranes, which have a high and regulated porosity. Treatment of polycarbonate surfaces with methacrylic acid or acrylic acid is expected to add carboxyl function groups to the surface.
Polyester Surfaces
[0057] Polyester surfaces were also obtained and tested, e.g., Millipore polyethyleneterephthalate (PET) membranes were obtained, Cat. No. T6PN1426, from Millipore Corp., Billerica, Mass., USA. These membranes were 47 mm in diameter, 0.013 mm thick, with pores having a nominal diameter of 1.0 μm. The membranes were cut into 3 cm×3 cm squares and added to a solution of water and acetone in a screw-cap bottle. 7.5 mmol of methacrylic acid, followed by 0.090 mmol of benzoyl peroxide in 2 ml acetone, were added to the solution. The bottle was rotary shaken at 85 C for 4 hours. The resulting membrane was thoroughly washed several times with hot water, followed by acetone, and then dried under vacuum to yield membrane PET-1. Without being bound to any particular theory, it is believed that this treatment results in substitution of a benzene ring hydrogen in the terephthalate moiety by the acrylic functionality. The membranes were tested, and treatment by acrylic acid resulted in weight gains of 50-53 percent. It is also believed that the subsequent treatment with benzoyl peroxide results in attachment of carboxyl groups to the polyester or PET surface. At least some of the attachments may be of a polymeric rather than monomeric nature, i.e., the attachments may be at least short chains with multiple carboxyl terminations. The terminal amine groups of the 4,6-dichloro-2-[2-(6-amino-hexyl-4-pyridinio)vinyl]phenolate dye, or of an antimicrobial agent, can then attach to the carboxyl groups, with the elimination of water.
[0058] A solution of the dye was prepared as follows for the PET membranes. 0.25 mmol of the di(trifluoroacetate) salt was dissolved in 10 ml of DMF, to which was added 0.51 mmol of triethylamine. 0.30 mmol of EEDQ (2-ethoxy-1-ethoxycarbonyl-1,2 dihydroquinoline) coupling agent was added. The PET-1 membrane was added to this reaction solution and was rotary shaken overnight. The resulting membrane was thoroughly washed with methanol. This membrane had a light orange/red color. It is believed that the residual carboxyl groups may protonate the phenolate moiety of the dye, rendering it colorless. Therefore, the membrane was surface-treated with a 5% sodium bicarbonate solution to convert any remaining carboxy groups to the sodium salt. The membrane was then washed with water, followed by methanol, and dried under vacuum to yield the PET-2 membrane. The dry film was orange/red. When wetted with 70% IPA, the membrane became a light salmon color, and changed to a salmon color when tested with IPA alone. In further experiments, it was found that increasing the treatment time of the membrane by the dye solution caused a more intense coloration of the membrane.
[0059] The results of these tests demonstrate that several substrates are suitable for the attachment of solvatochromic dyes, or may be treated so that the dyes easily attach. In addition to the particular materials tested, urethane membranes and foams may be used, perhaps without any treatment because of the NHCOO functional groups inherent in urethanes. These results demonstrate that discrete, small rings or membranes, such as those cut from a sheet, may be used. Other polymeric surfaces useful in embodiments include thin films, cast films, molded or shaped parts, or even thin coatings intended for placement on another object, for example, a vascular access device, such as a luer access device.
[0060] As discussed above, acrylic membranes or coatings may be used, at least for Reichardt's dye without treatment. The presence of polyester-like RCOO groups in acrylic polymers renders them suitable from the start for attachment of amine-containing dyes or antimicrobials, as well as other dyes. Urethane membranes or foams may be used as is, or they may be treated to make them even more suitable for dye or antimicrobial attachment. Polyimides may suitable if they are flame- or plasma treated, or if foamed polyimides are used. Melamines, maleic anhydride derivatives, blends and co-polymers may also be useful, as may blends, co-polymers and composites of any of these materials. Silicones are less amenable to treatment, however, foamed silicones may be used. For example, treating silicone with 5-10 M NaOH for several hours forms Si—OH (silanol) groups, which can then be used to form carboxy or other functional group attachment sites.
Solvatochromic Dyes
[0061] The dyes described above, Reichardt's dye, 4,6-dichloro-2-[2-(6-acrylamido-hexyl-4-pyridinio)vinyl]phenolate, and 4,6-dichloro-2-[2-(6-amino-hexyl-4-pyridinio)vinyl]phenolate, are only a few of many examples of useful solvatochromic dyes that may be used in these applications. There are many other solvatochromic dyes that could be used. As noted above, the principal requirements are the ability to reversibly change color when swabbed, e.g., with IPA. Without being bound to any particular theory, it is believed that the conjugation between the pyridine ring and the benzene ring, with the intermediary double bond, whether one, two, or three, that accounts for the solvatochromic activity in the new structures. Since these structural features are present in merocyanine dyes, it is believed that a number of these dyes would also be effective as indicators for swabbing, whether incorporated into a coating, as the acrylics described above, or used as part of a surface treatment. Of course, merocyanine dyes typically have a phenoxide ring, rather than a substituted benzene ring. The phenoxide ring functions as the aromatic donor and the pyridine or pyridinium ring functions as the acceptor. Of course, in the new structures, the benzene ring is the donor and the pyridine ring is the acceptor. Thus, it is believed that merocyanine dyes, structure 14 below, with conjugated pyridinium-phenoxide rings (having resonance with a pyridine-benzene structure)
[0000]
[0000] are also suitable. Examples include 1-methyl-4-(4′-hydroxybutyl)pyridinium betaine and Brooker's merocyanine dye, 4′-hydroxy-1-methylstilbaxolium betaine.
[0062] Other solvatochromic dyes may also be used, such as an abundance of previously-known dyes, and for which the small change from their normal environment to a slightly acidic environment, such as the 6-7 pH range of IPA, will produce a color change. The table below lists a number of these dyes and their colors before and after. Note that the “before” environment of the coating or LAD housing material may be altered, such as by making it basic, by simple adjustments during the formation of the coating, the method of treating the surface, or the species used for attaching the dye. A few examples of solvatochromic dyes are presented in Table 2 below.
[0000]
TABLE 2
Solvatochromic Dyes
First state
Second
Dye
pH
Color
state, pH
Color
Bromocresol purple
6.8
blue
5.2
yellow
Bromothymol blue
7.6
blue
6.0
yellow
Phenol red
6.8
yellow
8.2
red
Cresol red
7.2
red
8.8
Red/purple
Methyl red
4.2
pink
6.2
yellow
Reichardt's Dye
Unk
green
6-7
dark blue
Morin hydrate
6.8
red
8.0
yellow
Disperse orange 25
5.0
yellow
6.8
pink
Nile red
Unk
Blue/purple
6-7
bright pink
[0063] These and many other solvatochromic and merocyanine dyes many be used in applications according to this application. Other solvatochromic dyes include, but are not limited to, pyrene, 4-dicyanmethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran; 6-propionyl-2-(dimethylamino)naphthalene; 9-(diethylamino)-5H-benzo[a]phenoxazin-5-one; phenol blue; stilbazolium dyes; coumarin dyes; ketocyanine dyes, Reichardt's dyes; thymol blue, congo red, methyl orange, bromocresol green, methyl red, bromocresol purple, bromothymol blue, cresol red, phenolphthalein, seminaphthofluorescein (SNAFL) dyes, seminaphtharhodafluor (SNARF) dyes, 8-hydroxypyrene-1,3,6-trisulfonic acid, fluorescein and its derivatives, oregon green, and a variety of dyes mostly used as laser dyes including rhodamine dyes, styryl dyes, cyanine dyes, and a large variety of other dyes. Still other solvatochromic dyes may include indigo, 4-dicyanmethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM); 6-propionyl-2-(dimethylamino)naphthalene (PRODAN); 9-(diethylamino)-5H-benzo[a]phenox-azin-5-one (Nile Red); 4-(dicyanovinyl)julolidine (DCVJ); phenol blue; stilbazolium dyes; coumarin dyes; ketocyanine dyes; N,N-dimethyl-4-nitroaniline (NDMNA) and N-methyl-2-nitroaniline (NM2NA); Nile blue; 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS), and dapoxylbutylsulfonamide (DBS) and other dapoxyl analogs. Other suitable dyes that may be used in the present disclosure include, but are not limited to, 4-[2-N-substituted-(1,4-hydropyridin-4-ylidine)ethylidene]cyclohexa-2,5-di-en-1-one, red pyrazolone dyes, azomethine dyes, indoaniline dyes, and mixtures thereof.
[0064] Other merocyanine dyes include, but are not limited to, Merocyanine dyes (e.g., mono-, di-, and tri-merocyanines) are one example of a type of solvatochromic dye that may be employed in the present disclosure. Merocyanine dyes, such as merocyanine 540, fall within the donor—simple acceptor chromogen classification of Griffiths as discussed in “Colour and Constitution of Organic Molecules” Academic Press, London (1976). More specifically, merocyanine dyes have a basic nucleus and acidic nucleus separated by a conjugated chain having an even number of methine carbons. Such dyes possess a carbonyl group that acts as an electron acceptor moiety. The electron acceptor is conjugated to an electron donating group, such as a hydroxyl or amino group. The merocyanine dyes may be cyclic or acyclic (e.g., vinylalogous amides of cyclic merocyanine dyes). For example, cyclic merocyanine dyes generally have the following structure 15, in association with structure 14 above:
[0000]
[0065] wherein, n is an integer, including 0. As indicated above by the general structures 14 and 15, merocyanine dyes typically have a charge separated (i.e., “zwitterionic”) resonance form. Zwitterionic dyes are those that contain both positive and negative charges and are net neutral, but highly charged. Without intending to be limited by theory, it is believed that the zwitterionic form contributes significantly to the ground state of the dye. The color produced by such dyes thus depends on the molecular polarity difference between the ground and excited state of the dye. One particular example of a merocyanine dye that has a ground state more polar than the excited state is set forth above as structures 14 and 15.
[0066] The charge-separated left hand canonical 14 is a major contributor to the ground state, whereas the right hand canonical 15 is a major contributor to the first excited state. Still other examples of suitable merocyanine dyes are set forth below in the following structures 19-29, wherein, “R” is a group, such as methyl, alkyl, aryl, phenyl, etc. See Structures 19-29 below.
[0000]
[0067] In addition to dyes and antimicrobial compounds, the preparations discussed herein may be used to attach to desired surfaces other compounds or substances containing amino alkyl groups. Examples of these types of compounds include poly(ethylene glycol) (PEG)-containing amino alkyl groups, peptides including antimicrobial peptides, proteins, Factor VIII, polysaccharides such as heparin, chitosan, hyaluronic acid derivatives containing amino alkyl groups, and condroitin sulfate derivates containing amino alkyl groups. One example of a protein is albumin, and an example of a peptide is polymyxin. The one thing these compounds have in common is an amino alkyl group, such as the amino alkyl group discussed above in the new dye, 4,6-dichloro-2-[2-(6-aminohexyl-4-pyridinio)vinyl]phenolate.
[0068] Per the discussion above for surface preparation, the same preparation used to attach dyes and antimicrobial compounds containing alkyl amino groups will be suitable for these additional compounds. The amino alkyl groups will bind to the N-succinimidyl carboxylate groups. One technique for treating these groups is to clean the surface, followed by treatment with acid at elevated temperature, and then contacting the surface with poly(N-succinimidyl)acrylate (PNSA). It is believed that this induces carboxylate groups on the nylon surface, suitable for binding to aminoalkyl groups. Other methods are also described. For polycarbonate surfaces, treating with chlorosulfonic acid followed by washing is believed to induce chlorosulfonyl groups. These are suitable for binding by aminoalkyl groups. The treatment above of the PET surfaces is believed to result in attachment of carboxyl groups to the surface, making the also suitable for attachment of aminoalkyl groups.
[0069] Thus, polymeric surfaces as described above may also be used for attachment of peptides, proteins, Factor VIII or other anti-clotting Factors, polysaccharides, polymyxins, hyaluronic acid, heparin, chitosan, condroitin sulfate, and derivatives of each of these.
[0070] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
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A method for immobilizing dyes and antimicrobial agents on a porous surface is disclosed and described. The surface may be that of a medical device, such as a catheter, a connector, a drug vial spike, a bag spike, a prosthetic device, an endoscope, and surfaces of an infusion pump. The surfaces may also be one or more of those associated with a dialysis treatment, such as peritoneal dialysis or hemodialysis, where it is important that working surface for the dialysis fluid be sterile. These surfaces include connectors for peritoneal dialysis sets or for hemodialysis sets, bag spikes, dialysis catheters, and so forth. A method for determining whether a surface has been sterilized, and a dye useful in so indicating, is also disclosed.
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BACKGROUND OF THE INVENTION
This invention relates to ornamental or decorative illumination devices, and more particularly to psychedelic lighting devices. The devices may be termed visual works of art and are employed to create visual effects producing various sensations or moods in the mind of the observer.
Psychedelic lighting is characterized by intensified sensory perception, sometimes accompanied by significant perception distortion. When psychedelic lighting is integrated with a rotating display, dramatic visual effects may be obtained. Heretofore visual effect producers of various types have been known, as, for example, those including a source of visible light, the light source impinging its rays upon a patterned translucent film which is adapted for motion relative to the light source. As a result, the film transmits a luminous flux which varies with the variations of the pattern. Also, it is known to provide visual effects by employing a source of ultraviolet radiant energy which is outside of the visible spectrum, but which, when impinged on various materials, causes them to fluoresce. Such radiant energy is conventionally known as "black light," which term will be hereinafter employed. The black light source is employed in conjunction with the materials subject to fluorescence by employing the materials as coatings on various objects.
SUMMARY OF THE INVENTION
A principal object of the instant invention is the provision of a visual effects producer employing a source of black light and a patterned rotating blade apparatus subject to fluorescence.
In accordance with the instant invention, the black light source and apparatus include variable intensity and speed controls whereby novel effects are provided which heretofore have not been obtainable.
The construction and the effects of the instant invention herein described are different from previous patents. It is known that colored flat disks, cones, rotating cylinders, optical devices and concave rotating surfaces illuminated by a wide variety of lighting have been used in chromatic blenders, etc., to create certain color combinations and shading. See U.S. Pat. No. 1,547,864 (Etcheto) where colored changing rings appear to the viewer; U.S. Pat. No. 4,307,528 (Dewees) where a rotary reflector gives the illusion of light appearing to rotate in opposite directions; U.S. Pat. No. 2,107,860 (Gilbert) which discloses stationary cones on a planetary wheel that produces a variety of color blendings; U.S. Pat. No. 3,772,511 (Marban) in which flickering effects have been achieved by conventional light bulbs or the use of florescent black lighting described in U.S. Pat. No. 3,791,058 (Mollica). However, the visual effects from the instant invention have not been produced.
These together with other objects of the invention, along with various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the invention.
FIG. 2 is a side elevational view of the invention.
FIG. 3 is a front elevational view of the blade apparatus.
FIG. 4 is a side elevational view of a portion of the blade apparatus, partially exploded.
FIG. 5A is a front graphic illustration of blade assembly returned to a stable state after radical changes in light pulse to blade r.p.m. ratios.
FIG. 5B is a front graphic illustration of blade assembly when in the process of returning to a stable state after radical changes in light pulse to blade r.p.m. ratios.
FIG. 5C is a front graphic illustration of blade assembly when beginning to return to a stable state after radical changes in light pulse to blade r.p.m. ratios.
FIG. 6A is a top graphic illustration of the effects on the blade assembly from centrifugal and centripetal forces from 0-500 r.p.m. (revolutions per minute).
FIG. 6B is a top graphic illustration of the effects on the blade assembly from centrifugal and centripetal forces from 500 -1000 r.p.m.
FIG. 6C is a top graphic illustration of the effects on the blade assembly from centrifugal and centripetal forces from 1000 -2000 r.p.m.
FIG. 7 is a top graphic illustration of the rocking motion of the blade assembly at full r.p.m.
FIG. 8 is a front elevational view of a light pattern generated by the present invention during operation.
FIG. 9A is a front graphic illustration of the blade assembly when the ratio between light pulsing rate and blade r.p.m. is 1:1.
FIG. 9B is a front graphic illustration of the blade assembly when the ratio between light pulsing rate and blade r.p.m. is 3:1.
FIG. 9C is a front graphic illustration of the blade assembly when the ratio between light pulsing rate and blade r.p.m. is 4:1.
FIG. 9D is a front graphic illustration of the blade assembly when the ratio between light pulsing rate and blade r.p.m. is 30:1.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings in detail wherein like elements are indicated by like numerals, there is shown an embodiment of the invention 1 incorporating a rotating display. The invention has a front 2, back 3, two sides 4, top 5 and bottom 6. The invention is comprised of three major elements, a blade apparatus 10, a black light 40, and a control mechanism 50. The blade apparatus 10 is mounted on a platform or table 30 and is positioned so that it faces the front 2 of the invention 1. The blade apparatus 10 consists of four blades 11 made out of a thin, flexible plastic or similar material. In other embodiments, three blades or five blades could be used. The blades 11 rotate in a plane parallel to the front 2 of the invention 1 and are mounted on a hub 20 which in turn is connected to a variable speed motor 35 to the rear of the blade apparatus 10. The motor 35 is mounted on the top 31 of the table 30 near to the table's top front edge 33. The motor 35 provides rotational torque to the blades apparatus 10. The blade apparatus 10 and motor 35 may optionally be housed within a box (not shown) having an open front, back, top, bottom and two sides. The general plane of the blades would be parallel to the box front plane. Regardless of whether a housing is used or not, the hub 20, motor 35 and table 30 are painted a flat black color. The blades 11 in this embodiment are painted a royal blue color. In addition, the blades 11 are patterned with fluorescent paint. The pattern is comprised of a red band near to the outer radial periphery 12 of the blades 11.
The hub 20 has a generally cylindrical shape with a front 21, middle portion 26 and a back 22, and a longitudinal axis in a front to back horizontal plane. The hub 20 also has an interior grooved opening (not shown) along its central longitudinal axis. The motor 35 has a direct drive arm 36 extending horizontally outward from the motor 35 toward the front 2 of the invention 1. The drive arm 36 is longitudinally grooved 37 and coacts with the groove in the interior hub opening when the hub 20 is slid onto the motor drive arm 36, thereby locking the hub 20 to the motor arm 36. The hub front 21 terminates in a plate 24 having a diameter slightly greater than the hub's cylindrical diameter. The hub rear 22 terminates in a plate 25 having a diameter approximately twice that of the hub's cylindrical diameter. The hub rear plate 25 has a central opening (not shown) corresponding to the interior opening of the hub. The hub front plate 24 is painted black. Its front face 28 has a small fluorescent orange circle 27 centrally located, and has a geometric design 29 made of fluorescent yellow painted on its face 28.
The blades 11 each have a triangular, pennant-like shape. The points 13 of each blade triangle may be defined as points A, B, and C. Point C has the smallest interior angle. Point B has the interior angle closest to ninety degrees. And Point A has an interior angle less than the interior angle of B but more than the interior angle of C. The triangular blade 11 is connected at point B to the hub's rear plate 25. Side B--A of the blade 11 extends radially outward from the rear plate 25 along a line approximately parallel to the radial axis of the rear plate 25. The blade 11 is then curved forwardly so that Point C is attached to the hub's front plate 24. Each of the blades 11 are attached in the same manner and are equispaced radially about the hub 20.
A black light source 40 is positioned approximately two feet in front and generally below the blade apparatus 10. The source 40 is aimed upwardly, approximately forty-five degrees at the blade hub 20. The source 40 in this embodiment is comprised of a twenty-four inch fluorescent black light blue bulb 41 in a conventional electrical circuit connected to a pulse generator (not shown) contained within a black light source housing 42.
The control mechanism 50 is comprised of a simple console 51 with two rotatable knobs 52, 53. The first knob 52 controls the rotational speed of the motor 35. The second knob 53 controls the pulsing rate of the bulb 41 by means of the pulse generator. Clockwise turns of the knobs 52, 53 increase speed or pulse rates. Counterclockwise turns decreases motor speed or pulse rates.
The construction of the blades 11 contributes to a series of new and unexpected effects. As stated above the curved surfaces of the blades 11 are made of flexible plastic which change shape and dimension depending on the rotational speed of the motor 35. When the blades 11 are initially set in motion, torque is created in which the first change in the flexible plastic blades take place. The blades 11 twist in a circular or counterclockwise fashion. When the rotational speed is reduced the blades 11 turn clockwise back towards their original forms.
In addition to the above torque phenomena there is also an effect on the blades 11 from contradictory centrifugal (moving or directed outward from the center) and centripetal (directed toward the center) forces. When rotational speed is varied, the gravitational tendency to radially throw or push the flexible plastic construction out, i.e., flatten, at higher speeds or to radially pull inward when the speed of the blades is decreased causes the flexible plastic to be in a constant bouncing motion that gives the appearance of something animated, cellular or organic. The most striking impression is that it appears to be alive or breathing. FIGS. 6A, 6B and 6C best illustrate this effect.
A still additional effect is caused by the resistance of the turning blades and their appendages to the surrounding air. The curved surfaces of the blades are pointed in the opposite direction of a conventional air circulating fan. Instead of scooping or driving agitated air towards the operator, the curved appendages slide over and are pushed away from the air. When the blades are rotated at progressively higher speeds, the flexible blades and their appendages are forced out of wind resistance to contract or fold back towards the center point or hub. When the blades are rotated at even higher speeds, the flexible plastic construction begins to gently rock back and fourth in an unusual swaying motion and at maximum rotational speed the blades become violently agitated creating a whole new dynamic. FIG. 7 diagrammatically illustrates this phenomena.
When the effects described above are combined together, the resulting appearance is one of an oscillating breathing sphere that is vividly similar to transparent soap bubbles or fiery opalescent waves of scintillating light in which the viewer can look down through the ethereal composition as if it had many dimensions. The pictures formed in the center of the rotating blade apparatus are strikingly reminiscent of the shapes of living flowers viewed under time lapse photography that appear, dissolve, only to reappear.
To all the phenomena described above can be added the additional effect of the black light illuminating the blade apparatus 10. The black light shining on the blade apparatus 10 creates a lattice work of triangles of light and splinters of colored fragments cascading in and around the hub 20 of the rotating blades 11 and their outer peripheries 12 and also creates certain pools of congested effects. In these vibrational conditions color and forms do not stay as stationary petal formations nor do they simply dissolve into the homogeneous unity earlier described, but rather specific and newly colored overlapping light bands that are distinctly different from any previous phenomenon described are created. The colors and forms in these vibrational conditions run side by side in the same direction until a change in the ratio of light pulse rate and blade rotational speed is made and then run in opposite directions.
When the basic effects described above are combined with the control effects of the pulse generator working through the black light source 40, unexpected visual effects take place. The present invention may be superficially compared to the simple and one dimensional mechanics of the spirograph. When the speed of the rotating blades 11 is mathematically related to the flash of the pulsing light coming from the black light source 40, colored geometric patterns are created. Unlike the spirograph which can only create designs in a one dimensional and sequential order, the present invention can create an infinite variety of designs, one distinctly different from another. The present invention has the additional characteristic of being able to superimpose these designs simultaneously, one upon the other, in the same space and at the same time. It is this constant overlapping or overlaying of an infinite number of moving designs that gives the present invention an animated third and fourth dimensional effect. Visually, the observer may see a pattern as illustrated in FIG. 8.
Because of the speed at which this superimposition takes place and the infinite degrees of design and blending that are possible at any given moment, it is difficult to understand this ratio of light pulse to blade rotation without further explanation. At certain ratios of speed to pulse the rotating forms merge and reinforce each other. At other ratios of speed to pulse they cancel each other out creating new visual dynamics. Thus, around the circumference of the rotating blades 11 the overall pattern oscillates inwards and outwards to the visual eye thereby creating a variety of blended yet distinctive forms or divisions. These divisions are like the petals of a flower and conform to an algebraic formula, part of which is clearly obvious and can be controlled or regulated, and part of which is yet undefined because there are so many different factors involved.
As may be most clearly understood from an examination of FIGS. 9A-9D, if the four petals (blades 11) are exactly rotated to the same mathematical ratio of the pulse rate from the black light source 40 illuminating the surface of the blades, i.e., a 1:1 ratio, then the visual effect will be of a dancing and flashing design not unlike a four petalled flower. But as the ratio of pulse speed changes the four petals will change in appearance. At a ratio of 3:1, where the light is pulsing at three times the speed of the rotating petals, the four rotating blades 11 will appear as twelve petals. A further increase in the ratio to 4:1 will result in the appearance of a sixteen petalled flower. At a ratio of 30:1 there appears to be one hundred twenty petals.
During any changes of blade rotational speed to light pulse rate while the blades are in motion, the blades rotational direction will appear to change from clockwise to counterclockwise or vice versa. This in itself is not a unique effect. However, during radical changes in the ratio the effects from all of the factors described above produces a new visual effect. Specifically, if there is even the smallest change in the ratio of light pulse rate to blade rotational speed, the petals in multiples of four become superimposed upon each other so that what is viewed is that of a changing vortex or funnel of light. This effect, which can be regulated by the operator of the controls, is like a multidimensional kaleidoscope that can be seen first spiraling in towards the throat of the rotating blades and then out towards the outer periphery like an undulating transparent corkscrew. When the ratios of light pulse rate to blade rotational speed are radically altered the normal and more stable petal effects are even more violently thrown out of their normal balance. It is this wild gyration of motion in which the petal formations break down and a vortex or funnel effect begins to appear.
The creation and dissolution of light, color and form into rotating, cyclic and spiral motion is characteristic of cymatic (wave) effects. Colors, bands and ribbons of light can be controlled by an operator using the invention's control mechanism 50. By merely adjusting either the speed of blade rotation or the pulse rate of the black light source, the operator can cause the above described effects to cascade from the inside throat or diameter of the blade apparatus to its outer periphery only to spiral back again with a simple adjustment of the control mechanism. This inward and outward dynamic wave motion is particularly typical of the action of certain processes in nature such as wind currents, snow drifts, air and water flows, fluid dynamics and modern wave theories in physics. It is possible from the outline and description given for the operator of this invention to become a visual artist and learn to create an endless variety of dancing homogeneous forms of light and color just as a conventional artist can be trained to work with clay, tempera or oils.
It is understood that the above-described embodiment is merely illustrative of the application. Other embodiments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.
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A visual effects producer employing a source of black light and a patterned rotating blade apparatus subject to fluorescence. The black light source and blade apparatus include variable intensity and speed controls whereby novel effects are provided.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to adaptive sensing systems and more specifically to adaptive sidelobe cancelers utilizing an iterative mathematical process to calculate signals which control phase shift and attenuator circuits to produce RF signals which are combined in an analog summer to modify the sidelobe characteristics of the main antenna to reduce the effect of an interfering signal.
2. Description of the Prior Art
Typical prior art sidelobe canceling systems have utilized either all digital or all analog techniques to correct the final output signal of the system to perform the sidelobe canceling. Additionally, in an all digital system, no correction was made until the mathematical computations necessary to complete the cancellation process had been performed. The time required to complete the mathematical calculations determined the time required for the system to adapt to a particular interference situation. When scanning occurred or when the interfering signal source was moving relative to the antenna, the relative velocity between the major beam pattern and an interference source could significantly reduce the effectiveness of the system.
SUMMARY OF THE INVENTION
The preferred embodiment of the invention comprises an adaptive sidelobe canceling system. The main antenna provides a composite RF signal. A second group of auxiliary signals is produced by either a group of independent sensing elements or by tapping the output signals of a selected number of elements of a phased array antenna in a system utilizing such an antenna. The composite signal is coupled to the input of an analog summing circuit. Similarly, the group of auxiliary signals are also coupled as input signals to the analog summing circuit through amplitude and phase shift means. A digital arithmetic circuit senses the output signal of the summing circuit and the auxiliary signals to produce by an iterative mathematical process signals which control the amplitude and phase shift means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram illustrating the invention;
FIG. 2 is a diagram illustrating the angle amplitude response of a typical antenna;
FIG. 3 is a diagram illustrating the main beam and the auxiliary channel response of a typical antenna;
FIG. 4 is a response diagram of a typical system after response modification for interference canceling;
FIG. 5 is a more detailed diagram illustrating the invention;
FIG. 6 is a diagram illustrating the iterative process used to update the weighting function; and
FIG. 7 is a diagram illustrating the performance of the disclosed sidelobe canceling system.
DETAILED DESCRIPTION
FIG. 1 is a functional block diagram illustrating the invention. Functionally the system automatically changes or adapts the receive sidelobe response pattern of a main antenna 10 to reduce the sensitivity to interference signals which may be in one or more of the sidelobes of the antenna response. In the case of a phased array antenna each element of the antenna 10 produces a distinct output signal. In FIG. 1 only composite output signal and the auxiliary channels which are used for sidelobe response modification are illustrated. For purposes of describing the function of the system the number of elements in the array 10 and the number of auxiliary is not important.
The composite output signal of the antenna 10 is coupled to a summing circuit 12 via an interconnect path 14. Additionally, three auxiliary signals are coupled to an analog beam forming network 20 via interconnect paths 22, 24 and 26 and to a digital weight generation circuit 28 via an interconnect paths 30, 32 and 34. The digital weight generation circuit 28 generates control signals which are inputted to the analog beam forming circuit 20 via interconnect path 36. Analog beam forming network 20 generates a plurality of RF output signals having a predetermined phase and amplitude with respect to the composite signal. These signals are coupled as inputs to the summing circuit 12. The output signal of the summing circuit 12 is a signal in which interference signal appearing in the side bands is suppressed.
As an aid in describing the invention and how it adapts to reduce the response to an interference signal appearing in one of the sidelobes, the response characteristic of a typical antenna is illustrated in FIG. 2. Typically the response pattern 40 is symmetrical around the major beam axis 38. Additionally there are a series of sidelobes which get progressively smaller as the distance from the center of the main lobe increases. The five major sidelobes of the antenna are illustrated generally as reference numeral 42.
For purposes of describing the invention, it is assumed that an interference signal is positioned such that it is within the second sidelobe or along an axis 44 as illustrated in FIG. 2. The operation of the system will be described to illustrate how the response characteristic of the antenna 40 is modified to reduce the effect of this interference signal.
In FIG. 3 the response characteristic of the main beam of the array is illustrated generally at reference numeral 40. Similarly, the response of the auxiliary channels is illustrated at reference numeral 46. This clearly illustrates that the overall gain of the auxiliary channels is considerably lower than the main beam. The auxiliary channels may be provided by suitable apparatus to tap a small signal from a number of elements of the array 10. Alternatively, completely separated wide band antennas such as horns, for example may be used. Separate wide band antennas are particularly useful when the main antenna is not a phased array. This overall gain characteristic of the auxiliary channels is utilized to determine the maximum amplitude and phase adjustments as described below.
FIG. 4 is the response characteristic of the main antenna 10 after the response characteristic has been adjusted to reduce the gain of the sidelobe along axis 44 to substantially zero. As illustrated in FIG. 4 the response of the main beam 40 is substantially the same as the main beam response in FIG. 2. However, the width of the first sidelobe has been narrowed such that the axis 44 is positioned at the midpoint between the second and third sidelobes resulting in a position at which the response of the array is substantially zero. This permits the response to be adjusted such that it has substantially zero response to any interference signal appearing along axis 44. The response characteristic also adjusted to similarly reduce the response to multiple interference signals.
The operation of the invention will be described in detail with reference to the block diagram of FIG. 5. The composite signal from the main antenna 10 is coupled to the summing unit 12 as previously described. Additionally the auxiliary channel signals 1 through N are coupled to the summer 12 through individual analog gain and phase adjusters with the gain and phase adjuster for the first channel being illustrated at reference numeral 46 and the gain and phase adjuster for the N channel being illustrated at reference numeral 48. As previously discussed, the number of auxiliary channels will depend on the application with the four channels being typical.
The RF signal from the first channel is coupled to a first receiver 50 to generate at the output of this receiver a conventional video signal. This signal is sampled and digitized at a suitable rate by an analog digital converter 52. The digitized video signal from the analog digital converter 52 is coupled as an input signal to a clutter canceler 54 to produce at the output of this circuit a video signal free of clutter. Similarly, the output signal of the Nth channel is coupled to a receiver 56, analog-to-digital converter 58, and clutter filter 60 to produce at the output of the clutter canceler 60 a video signal from channel N. These two clutter canceled signals are coupled as inputs to a covariance matrix algorithm circuit 62.
Similarly, the output signal of the summer circuit 12 is coupled as an input to the principle receiver 64. The output of the receiver 64 is a conventional video signal which is sampled by an analog digital converter 61 to generate at the output of this analog digital converter a series of digital signals representative of the video input signal. This digitized video signal is the output signal of the sidelobe canceler and also the input signal to a third clutter canceling circuit 66. The output signal of the clutter canceler 66 is also coupled the covariance matrix algorithm circuit 62. Covariance matrix algorithm circuit 62 generates a series of digital numbers each specifying the gain and phase of an associated analog and gain phase network. For example, a first output of the covariance and matrix algorithm circuit 62 is a digital number which is coupled to the input of a first analog to digital converter 68 to generate at the output of this circuit an analog signal which adjust the gain and phase of a first analog and gain phase adjust circuit 46 to the desired value. Similarly, the covariance matrix algorithm circuit 62 generates a second output signal which is coupled as an input to analog-to-digital converter 70 to generate an analog signal which sets the phase and gain of phase and of a second network 48 to the desired value.
As previously described the invention utilizes a process for sequentially updating the control signals of the gain and phase circuit such that the interference is reduced in steps. This sequential process is illustrated in FIG. 6. For example, each frequency dwell is divided into a series of update periods. This is illustrated in FIG. 6 where the first update of the weights WC occurs at the end of the first update period. Each update period must be sufficiently long to permit at least one sample to be collected from each of the auxiliary channels. Each update period is preferably the same length with the updating process continuing so long as the radar is in operation.
FIG. 7 illustrates the sidelobe cancellation as the number of update cycles for a simulated radar system. From this figure it can be seen that after the third update cycle that the response to four simulated interference sources has been substantially reduced after twelve update cycles the response to these interference sources had been reduced to near background level. This figure also illustrates that the response to a single interference source can be reduced more rapidly. The procedure described above emphasizes the most recent data. This provides the capability of tracking non-stationary interference sources. A computational algorithm based on sequentially inverting the sample covariance matrix is utilized. Let X 0 (n+1) and X(n+1) denote the (n+1)-th samples of the main and the auxiliary channels. W(n) is the optimal weight estimate and M -1 (n) is the inverse of the covariance matrix obtained previously. On the arrival of the (n+1)-th time samples the weights are updated to W(n+1) and M -1 (n) th is updated to M -1 (n+1) based on the following equations: ##EQU1## The above equations are based on the standard covariance matrix algorithm used in sidelobe cancellation radars, modified to permit sequential updating. In the above equations α is the amplitude weighting factor which is employed to weight the significance of data sample, thus enabling the emphasizing of the most recent data. The system can be implemented using commercially available components.
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A system for adjusting the sidelobe response of a main antenna is disclosed. This iterative process results permits the sidelobe canceling in sequential step reduction in interference thereby greatly reducing the time required to respond to changes in the characteristics of the interference. The response of the phased array is adjusted by combining the composite signal from the main antenna with signals from auxiliary channels which have an adjustable phase and amplitude. The desired amplitude and phase of the auxiliary channels is determined using an iterative mathematical process which emphasizes the most recent data. Emphasizing the most recent data permits the system to be used in the scanning mode or to reduce interference from moving sources.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Phase of International Patent Appl.Ser. No. PCT/US2003/32537 filed Oct. 15, 2003, which claims the benefit of an earlier filing date under 35 U.S.C. § 120 to U.S. Provisional Appl. No. 60/470,705 filed Oct. 23, 2002.
FIELD OF THE INVENTION
The invention provides fast moisture and photo/moisture curing silicone compositions and methods for the preparation thereof. More particularly, the compositions provided are prepared from silanol and silane cappers; the cappers have an α-carbon bonded to the silicon atom allowing for a favorable hypervalent silicon transition state when reacting the silane and silanol. This favorable transition state enables both a fast endcapping reaction and contributes to the fast moisture curing properties of the inventive compositions.
BRIEF DESCRIPTION OF RELATED TECHNOLOGY
The quest for fast curing silicone compositions that are both simple and economical to prepare as well as useful in a variety of industrial applications has lead to many developments for such compositions in recent years (e.g. U.S. Pat. Nos. 4,528,081; 4,699,802; 4,675,346 assigned to Henkel Loctite Corporation and U.S. Pat. Nos. 5,405,888; 5,409,963; 5,489,622; 5,384,340, 5,340,847 assigned to Three Bond Co. Ltd.). Notably, Chu (Chu, H. K., in Silicones and Silicone - Modified Materials, ed. Clarson, et al., American Chemical Society, Washington D.C., 2000, pp 170-179) has reported that silanol terminated polydimethylsiloxane (PDMS) can be readily endcapped with acryloxymethyldimethylacryloxysilane by simply mixing this silane with silanol terminated PDMS. The reaction is generally complete within seconds after mixing as evidenced by the transformation of the clear silanol fluid into a cloudy mixture due to the low solubility of the liberated acrylic acid in silicone. Removal of acrylic acid by vacuum stripping, if needed, yields the clear acrylate endcapped polydimethylsiloxane. Addition of a photoinitiator, fillers and other types of additives common to RTV silicones results in photo (i.e. ultraviolet or “UV”) curable silicones.
The ease of this reaction was reported by Chu as being unexpected. In condensation reactions of acetoxysilanes with silanol, the reactivity of these silanes has been reported to be directly proportional to the number of acetoxy groups attached to silicon, presumably due to the electron withdrawing capability of the acetoxy groups that renders the silanes with more acetoxy groups more anenable to nucleophilic substitution. Thus, condensation with silanol takes place instantaneously with tetra-or triacetoxysilanes, but is orders of magnitude slower for diacetoxy-or monacetoxysilanes. Thus, acryloxymethyldimethylacryloxysilane, with only one acryloxy group directly attached to silicon, was reportedly expected to likewise react with silanol very slowly.
A reported explanation for the ease of this endcapping reaction was attributed to a hypervalent transition state (see Chu, above). Several similar silanes with a carbonyl group γ- to silicon have been shown to possess pentacoordinate silicon structures with an intramolecular coordinate Si←O═C bond. High reactivities of many such hypervalent silicon compounds have been observed and are attributed to the hypervalency of these silanes (see Chu, above). Although acryloxymethyldimethylacryloxysilane has been reported to be tetracoordinate, rather than exhibiting pentacoordinate hypervalency, the high reactivity between this silane and silanol has been attributed to the anchimeric assistance of the acryloxymethyl group on the leaving acryloxy group during endcapping of the silanol. A hexacoordinate hypervalent transition state (resulting from the intramolecular coordinate from both the Si←O═C bond and the O bond from the silanol) has been proposed to be responsible for the ease of the reaction (see Chu, page 178) and the proposed structure below:
Although as described above, photocurable silicon compositions have been developed using cappers such as acryloxymethyldimethylacryloxysilane that allow for a favorable silicon transition state resulting in fast endcapping reactions, compositions derived from such cappers that will result in moisture or dual (UV/moisture) curing silicone compositions are needed.
Furthermore, there is a need for faster curing moisture curable compositions. As is well known in the art, many moisture-curing silicone systems provide good physical properties and performance when fully cured, but they suffer from the disadvantage of slow cure. Bauer et al (“NCO-Silane Terminated Copolymers with Tunable Curing Rates”, Munich, 2001, 1 st European Silicon Days) have reported, however, that polymers derived from isocyanatomethylalkoxysilanes (i.e. those silanes having an α-carbon bonded to the silicon atom) and aminoalkyl/silicones result in an extremely enhanced curing rate, putatively due to the hypervalent transition state that occurs during curing (i.e. cross-linking of reactive silicones) when exposed to ambient conditions. However the isocyanatosilanes used to create these polymers may be of concern due to the undesirable toxicological effects of isocyanates in general.
Hence, there is a need in the art for photo/moisture curable and moisture curable compositions having fast moisture curing properties that can be prepared by simple, safe and economical methods and also allow for fast endcapping reactions
SUMMARY OF THE INVENTION
The invention provides compositions capable of fast moisture cure. The compositions, which include both hydrolyzable functional silanes and silanols may be exclusively moisture curing or dual (photo/moisture) curing. The silanes contain a single carbon linkage between the silicon atom and, for example, an acetyl or methacryloyl group (see structure I below). This linkage provides for the formation of a favorable hypervalent silicon transition state, allowing fast nucleophilic substitution on silicon during endcapping and curing reactions.
More particularly, the invention provides a composition including:
a) a compound having the structural formula:
wherein R is a C 1-20 alkyl which may be substituted or unsubstituted or an unsaturated free radical-curing group;
R 1 is hydrogen or a C 1-6 hydrocarbon radical; R 2 is a hydrolyzable group; X is oxygen or
R 3 is H or C 1-12 hydrocarbyl group; and
b) a polymer having the structure formula:
wherein A is a backbone selected from the group consisting of organic and siloxane backbones, and R e is CH 3 or H.
Further provided is a curable composition having the reaction product of
a) a compound having the structural formula:
wherein R is a C 1-20 alkyl which may be substituted or unsubstituted or an unsaturated free radical-curing group;
R 1 is hydrogen or a C 1-6 hydrocarbon radical; R 2 is a hydrolyzable group; X is oxygen or
R 3 is H or C 1-12 hydrocarbyl group; and
b) a polymer having the structure formula:
wherein A is a backbone selected from the group consisting of organic and siloxane backbones, and R e is CH 3 or H.
Furthermore, in another aspect of the invention there is provided a method of preparing a curable composition including the step of combining:
a) a compound having the structural formula:
wherein R is a C 1-20 alkyl which may be substituted or unsubstituted or an unsaturated free radical-curing group;
R 1 is hydrogen or a C 1-6 hydrocarbon radical; R 2 is a hydrolyzable group; X is oxygen,
R 3 is H or C 1-12 hydrocarbyl group; and
b) a polymer having the structure formula:
wherein A is a backbone selected from the group consisting of organic and siloxane backbones, and R e is CH 3 or H.
DETAILED DESCRIPTION OF THE INVENTION
In one aspect of the invention, a curable composition is provided having a silane capper compound of the formula:
wherein R is a C 1-20 alkyl which may be substituted or unsubstituted or an unsaturated free radical-curing group;
R 1 is hydrogen or a C 1-6 hydrocarbon radical; R 2 is a hydrolyzable group; X is oxygen or
R 3 is H or C 1-12 hydrocarbyl group; and
a silanol-terminated polymer having the structure:
wherein A is a backbone selected from the group consisting of organic and siloxane backbones, and R e is CH 3 or H.
In a desired embodiment, R 2 is selected from the group consisting of
wherein R′, R″, R″′ and R″″ is H or a monovalent substituted or unsubstituted C 1-6 hyd 1 rocarbon radical, and R 4 is a C 1-2 alkyl group.
In a particularly desired embodiment, R 2 is selected from the group consisting of
wherein R 4 is a C 1-2 alkyl group.
In a particularly desired embodiment, R 2 is an alkoxy group having the formula
R 4 O—
wherein R 4 is a C 1-2 alkyl group.
In another desired embodiment, R is a C 1-20 alkyl or C 2-20 alkenyl either of which may be substituted or unsubstituted.
Desirably, both moisture and photo curable groups are present on the silane capper of the invention. In this embodiment, the composition includes a silane capper wherein R includes an unsaturated free radical-curing group (i.e. a C 2-20 alkenyl which may be substituted or unsubstituted), capable of undergoing free radical cure, such as UV cure, and R 1 , R 2 , X, and R 3 are as described above and structural formula II is as described above.
In another desired aspect of the invention, a moisture curable composition is provided wherein the silane capper exclusively includes moisture curable groups. In this embodiment, the composition includes structural formula I wherein R is a C 1-20 alkyl which may be substituted or unsubstituted, R 1 , R 2 , X, and R 3 are as described above, and structural formula II is as described above.
Regardless of whether the final composition is curable by UV, moisture or both, the most desirable silane capper has the general formula III
wherein R, R 1 , R 2 and R 4 are as described above.
Among capper compounds of the general formula III set out broadly hereinabove, a preferred class of such compounds includes those in which the alkoxyfunctional silane contains a carboxyl group. Therefore, X is desirably O. Thus a preferred class of compounds are of the formula:
wherein R, R 1 and R 4 are as defined above.
In a particularly desired preferred embodiment, a photo/moisture curable composition is provided which includes a polymer according to structural formula II and an alkoxysilane according to structural formula IV wherein R is
and R 5 , R 6 and R 7 are independently selected from hydrogen, halogen and organo radicals, and R 1 and R 4 are as described above.
In a particularly desired embodiment, the structure of the silane capper used in the photo/moisture curing composition is an alkoxysilane of formula IV wherein R is structural formula V and R 5 and R 6 are H and R 7 is CH 3 . Hence, a particularly desired embodiment of the silane capper is that of structural formula VI below:
In yet, another desirable embodiment, the structure of the capper used in the curing composition of the invention is an alkoxysilane of structural formula IV wherein R is a methyl group and R 1 and R 4 are as described above. Thus, in this embodiment the desired structure is of structural formula VII below.
The synthesis of the silane cappers described above may be prepared by any desirable method known in the art. For example, the synthesis of an acryloxy-functional alkoxysilane such as that of structural formulas VI may prepared by using the following reaction step:
(a) reacting (i) a (meth)acrylic acid compound of the formula:
wherein R 5 , R 6 and R 7 are independently selected from hydrogen, halo and organo radicals, with (ii) a chlorosilane compound of the formula:
wherein R 4 is as described above.
In another embodiment, the proton in structural formula VII may be replaced with Na + or K + and reacted with structural formula IX.
In carrying out the reaction of the (meth)acrylic acid compounds with the chlorosilane compounds, it is generally advantageous to use a base such as triethylamine under refluxing xylene or dimethylformamide to function as a hydrogen chloride acceptor, thereby removing the hydrogen chloride formed in the reaction. In some instances, it may be feasible to remove the hydrogen chloride by-product by sparging the reaction mixture with nitrogen, whereby the passage of nitrogen throughout the mixture removes the hydrogen chloride. Additionally, acrylate polymerization inhibitor such as hydroquinone (HQ) may also optionally be added to the mixture.
In an alternative embodiment, where X in structural formula I is
wherein R 3 is H or a C 1-12 hydrocarbon radical, structural formula I may be formed by reacting amino methyltrialkoxysilane with methacryl chloride.
The reaction may be carried out at any suitable temperature; generally, temperatures on the order of from about 25° C. to about 150° C. are usefully employed and preferably from about 100° C. to 140°, most preferably at about 120° C. The time required to carry out the reaction may be readily determined for a given reaction system by simple analytical tests without undue experimentation, and the reaction time may be varied as necessary or desirable in a given application. By way of example, the reaction may be carried out in approximately 2-3 hours. After the reaction has been carried out, the reaction mixture may optionally be subjected to vacuum stripping or other suitable treatment for the removal of residual acrylic acid from the reaction mixture to the extent desired.
Similarly, an alkoxysilane capper of the invention containing an acetoxy functional group may be prepared by reacting acetic acid with structure IX to yield a reaction product such as that of structure VII where R 1 is H.
The silanol-terminated polymer of structural formula II can be virtually any useful silanol-terminated material. The silanol-terminated polymer as described above has the general formula
wherein A represents a polymer or copolymer backbone. The backbone can be any number of combinations of polyurethane, silicone, polyamide, polyether and the like. Desirably, A is an organic or a siloxane backbone. More desirably, A is a siloxane.
An example of one such silanol-terminated polymer is polydimethylsiloxane having the formula:
The number of repeating units will determine the molecular weight and hence the viscosity of this starting material. Thus, n can be, for example, an integer which, for example, can be from about 1 to about 1,200, desirably from about 10 to about 1,000. The viscosity of these materials is not critical and can easily be chosen to fit a particular product application, particularly because the hydrolyzable terminated end product of this reaction will have substantially the same viscosity as the silanol-terminated reactant. Viscosities of these silanol-terminated polymer backbone can range from about 1 cps to about 150,000 cps (Brookfield, 25° C.). Desirably, the silanol-terminated polymer backbone used in the present invention is from about 50 to about 150,000 cps. Useful silanol terminated polymers include those from about 50 cps silanol-terminated polydimethylsiloxane, to about 150,000 cps silanol-terminated polydimethylsiloxane and combinations thereof.
The invention also provides a curable composition including the reaction product of a silane capper as described above with the polymer of structural formula II also as described above. The reaction of structure I and II, due to the carbon diradical linkage between the silicon in the capper and the —X—CO—R group enables a favorable hypervalent silicon transition state during the capping reaction resulting in fast nucleophilic substitution on silicon.
Desirably, this reaction product cures in less than about 20 minutes. More desirably the reaction product cures in less than about 15 minutes. Even more desirably, the reaction product cures between about 3 minutes and about 14 minutes. Yet, even more desirably, the reaction product cures in about 5 minutes.
The determination that the reaction product is cured is measured by examining the skin over time. As used herein, “skin over time” refers to the time it takes for a spatula to no longer pick up liquid upon contact with a reaction product.
The reaction of structure I and structure II of the present invention is desirably performed in the presence of a catalyst. Desirable catalysts include organo-lithium reagents, which are represented by the formula LiR 12 wherein the organo group R 12 is selected from the group consisting of C 1-18 alkyl, C 1-18 aryl, C 1-18 alkylaryl, C 1-18 arylalkyl, C 2-18 alkenyl, C 2-18 alkynyl, amine-containing compounds, as well as organosilicon-containing compounds. R 12 can have from 1 to 18 carbon atoms in the chain (C 1-18 ). These reagents provide enhanced processing and improved quality of product made therefrom
The organo-lithium catalyst is preferably an alkyl lithium such as methyl, n-butyl, sec-butyl, t-butyl, n-hexyl, 2-ethylhexyl butyl and n-octyl butyl lithium. A particularly desirable catalyst is N-butyllithium in hexane (such as at 1.6 Molar concentration). Other useful catalysts include phenyl lithium, vinyl lithium, lithium phenylacetylide, lithium (trimethylsilyl) acetylide, lithium silanolates and lithium siloxanolates. The organo group can also be an amine-containing compound, such as dimethylamide, diethylamide, diisopropylamide or dicyclohexylamide, or a silicon-containing compound. (See, for example U.S. Pat. No. 5,300,608 (Chu); U.S. Pat. No. 5,663,269 (Chu) and U.S. Pat. No. 6,140,444 (Chu)).
The organo-lithium reagents are used in catalytically effective amounts. Generally, the catalytically effective amount of an organo-lithium catalyst will vary with the specific catalyst and reactant materials, but about 1 to 1000 ppm based on the atomic weight of lithium are useful. A more preferred range is 5-250 ppm. Removal of the residual organo-lithium catalyst can be optionally accomplished through filtration.
Other catalysts useful in, but less desirable, in preparing the reactive silicones include organometallic catalysts such as titanates and organo tin catalysts known in the art.
The reactive silicone compositions of the invention may further include a curing system. A curing system includes but is not limited to catalysts or other reagents which act to accelerate or otherwise promote the curing of the composition of the invention.
When moisture curing is desirable, the catalysts which may be included in the curing system of the invention include, but are not limited to, tin IV salts of carboxylic acids, such as dibutyltin dilaurate, organotitanium compounds such as tetrabutyl titanate, and partially chelated derivatives of these salts with chelating agents such as acetoacetic acid esters and beta-diketones and amines. Desirably, tetraisopropyltitanate, dibutyltin dilaurate and tetramethylguandine at levels of 0.05-0.5% are used.
Where photo curing is desirable, any known radical photoinitiators can be included in the compositions of the invention. Photoinitiators enhance the rapidity of the curing process when the photocurable compositions as a whole are exposed to electromagnetic radiation. Examples of suitable photointiators for use herein include, but are not limited to, photoinitiators available commercially from Ciba Specialty Chemicals, Tarrytown, N.Y. under the “IRGACURE” and “DAROCUR” tradenames, specifically “IRGACURE” 184 (1-hydroxycyclohexyl phenyl ketone), 907 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholino propan-1-one), 369 (2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone), 500 (the combination of 1-hydroxy cyclohexyl phenyl ketone and benzophenone), 651 (2,2-dimethoxy-2-phenyl acetophenone), 1700 (the combination of bis(2,6-dimethoxybenzoyl-2,4,4-trimethyl pentyl) phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one), and 819 [bis(2,4,6-trimethyl benzoyl) phenyl phosphine oxide] and “DAROCUR” 1173 (2-hydroxy-2-methyl-1-phenyl-1-propane) and 4265 (the combination of 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one); and the visible light [blue] photoinitiators, dl-camphorquinone and “IRGACURE” 784DC. Of course, combinations of these materials may also be employed herein.
Other photoinitiators useful herein include alkyl pyruvates, such as methyl, ethyl, propyl, and butyl pyruvates, and aryl pyruvates, such as phenyl, benzyl, and appropriately substituted derivatives thereof.
Photoinitiators particularly well-suited for use herein include ultraviolet photoinitiators, such as 2,2-dimethoxy-2-phenyl acetophenone (e.g., “IRGACURE” 651), and 2-hydroxy-2-methyl-1-phenyl-1-propane (e.g., “DAROCUR” 1173), diethoxyacetophenone, bis(2,4,6-trimethyl benzoyl) phenyl phosphine oxide (e.g., “IRGACURE” 819), and the ultraviolet/visible photoinitiator combination of bis(2,6-dimethoxybenzoyl-2,4,4-trimethylpentyl) phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (e.g., “IRGACURE” 1700), as well as the visible photoinitiator bis(η 5 -2,4-cyclopentadien-1-yl)-bis[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl]titanium (e.g., “IRGACURE” 784DC).
The amount of photoinitiator used in the composition will typically be in the range of between about 0.1% and 5% of the composition. Depending on the characteristics of the particular photoinitiator, however, amounts outside of this range may be employed without departing from the invention so long as they perform the function of rapidly and efficiently initiating polymerization. In particular, higher percentages may be required if silicone bound photoinitiators are used with high equivalent weight per photoinitiating group.
The inventive compositions may also contain other additives so long as they do not interfere with the curing mechanisms. The curable silicone compositions of the present invention can be mixed with or include other conventional additives such as viscosity modifiers such as trimethyl(silyl) terminated polydimethyl silicone, initiators, promoters, pigments, fillers, moisture scavengers and the like to form a one-part curable composition. Particularly useful fillers include fumed silica, silane treated, calcium carbonate, calcium carbonate (hydrophobic) and combinations thereof. Desirable pigments additives include carbon black. Moisture scavengers such as methyltrimethoxysilane and vinyltrimethyloxysilane are useful.
Other particularly useful additives include hexamethyldisilazane, vinyltrimethoxysilane, aminopropyltriethoxysilane and combinations thereof. Desirably, adhesion promoters include, but are not limited to, such as glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, methacryloxypropyltrimethoxy-silane, triallyl-S-tria-zine-2,3,6(1H.3H.5H)-trione aminoethylaminopropyltrimethoxysilane and others known to those skilled in the art. Fillers such as silica, microballoon glass and the like are useful for their conventional purposes.
The invention also provides a method of preparing a curable composition including the steps of reacting a silane capper according to structural formula I as described above with structural formula II. In this aspect of the invention, structural formula II may be devolitized under vacuum for an appropriate time period as is known in the art, generally 1-2 hours. The devolitization occurs at elevated temperatures, typically between 80° C. to 150° C., more desirably between 100° C. and 110° C. After cooling the silanol of structural formula II to between about room temperature to about 90° C., and more preferably from about room temperature to 75° C., the silane capper is added to the silanol.
Desirably, a catalyst is used to increase the rate of capping. Desired catalysts include the organic lithium catalysts described above. Desirably, N-butyllithium in hexane (1.6 M) is used. Endcapping under these conditions occurs immediately.
Although the silane capper of the invention and structural formula II may be utilized in any suitable proportions relative to one another consistent with the number of alcohol-reactive functional groups on structure II, it generally is preferred to utilize relative amounts of the inventive capper and structure II providing up to about 1.5 or more equivalents of silane for with the silane of structure II, and desirably the equivalents ratio of silane to alcohol-functionality is from about 1.0 to 1.2.
The method also provides a curing system as described above. Desired catalyst for use in moisture curing include but are not limited to tetraisopropyltitanate, dibutyltin dilaurate and tetramethylguandine as well as photoinitiators including those described herein above. Fillers or reinforcing materials, adhesion promoters, anti-oxidants, flame retardants and pigments, etc may also optionally be provided in the method of the invention.
EXAMPLES
Example 1
Preparation of methacryloxymethyltrimethoxysilane Inventive Capper
(Structural Formula VI)
A 500 ml three neck round bottom flask equipped with a mechanical stirrer and condenser were charged with 21.6 g sodium methacrylate, 40 ml dimethylformamide (DMF) and 0.04 grams of acrylate polymerization inhibitor, hydroquinone (HQ) and 34.20 g of chloromethyltrimethoxysilane. The mixture was heated under a closed system to 120° C. for 2.5 hours. After cooling to room temperature, the mixture was vacuum filtered and the DMF distilled under vacuum at 40° C. -45° C. The crude reaction product was further vacuum fractionated to yield 24.54 g of the capper (56% yield). Capper VII was similarly prepared using sodium acetate and chloromethyltrimethoxysilane.
Example 2
Preparation of Inventive Polymer A and C
Inventive polymer A was prepared by charging 1000 g of a 750 cps of hydroxyl-terminated polydimethylsiloxane into a 2 liter three neck round bottom flask and devolitizing the fluid under vacuum at 105° C. for one hour. The silanol was cooled to 75° C. and 40.29 g of capper (structural formula VI) prepared according to Example 1 was added to the silanol along with 1 ml of N-butyllithium in hexane (1.6 Molar). Endcapping occurred immediately as evidenced by transformation of the clear silanol fluid into a cloudy mixture due to rapid boiling of the liberated methanol in silicone. The mixture was vacuum stripped with stirring at 75° C. 20 g of Polymer A was then used to assess skin over time. Polymer C was similarly prepared, but using capper VII instead.
Example 3
Comparison of Inventive Polymer A with a Comparative Polymer B
Comparative polymer B is of identical composition to inventive polymer A except that the comparative capped polymers contain a propyl rather a methyl linkage to the silicon. Methylacryloxypropyl dimethoxysiloxy-terminated PDMS was used as comparative polymer B. Polymer C was prepared similarly as in Example 2 using methacryloxy propyl trimethoxy silane instead of methacryloxy methyl trimethoxy silane. Comparison of skin over times for inventive polymer A and comparative polymer B after addition of catalyst (tetraisopropyltitanate, TIPT) are shown in Table 1. TIPT was prepared by mixing 0.1 g TIPT with 5 g of methyl-terminated poly(dimethylsiloxane) before its addition to the polymers.
TABLE 1
Skin over time (SOT)
Polymer A
Comparative Polymer B
0.1% TIPT
40 min.
>24 hours
0.2% TIPT
24 min.
overnight
0.5% TIPT
12 min.
2.5-3 hours
As is evident from Table 1, moisture curing using the reaction product of the composition of the invention results in a much faster cure in comparison to compositions prepared from a silane having a propenyl linkage rather than a methyl linkage linked to the silicon.
Example 4
Skin Over Time of Inventive Polymer A in the Presence of Catalyst and Photoinitiator
23 g of inventive composition A was added to (MeN) 2 C=NH in a closed vial. The skin over time was 3 minutes when 0.2% (tetramethylguanidine) TMG was added to the mixture. When 1% photoinitiator, diethylacetophenone (DEAP) was also added, the moisture cure slowed to about 10 to 15 minutes. The formulation cured to silicone rubber when irradiated with a medium pressure mercury lamp with an intensity of 70 mW/cm 2 for 30 seconds.
Example 5
Skin Over Time for Inventive Polymer C: Comparison of Catalysts and Photoinitiator
The effect of different catalysts on skin over time of the inventive composition C was compared as shown in Table 2. Inventive composition C is an acetoxymethyltrimethoxysilane capped polydimethylsiloxane. The use of catalysts TIPT and TMG resulted in similar rates of skin over time. As shown in Table 2, the addition of photoinitiator, diethylacetophenone (DEAP) increased the rate of skin over time when used with the catalyst TIPT. The effect on skin over time is not effected when DEAP is used with TMG.
TABLE 2
Composition C
Curing agent
Skin over time
0.1% TMG
5
min.
0.2% TMG
2
min.
0.1% TMG, 1% DEAP
5
min.
0.3% TIPT, 1% DEAP
>10
min.
Examples 1-5 show that when the silane cappers used in the compositions have a methyl rather than a propyl linkage to the silane, faster curing in the presence of a moisture catalyst occurred, as measured by skin over time. Additionally, endcapping of the silanol occurred immediately upon addition of lithium catalyst.
The examples also reveal that particular catalysts, such as TIPT, will increase the curing time when used with the photoinitiator, DEAP. The catalyst, TMG, however, is not effected by DEAP and skin over time was 5 minutes.
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The invention provides fast moisture and photo/moisture curing silicone compositions and methods for the preparation thereof. More particularly, the compositions provided are prepared from silanol and silane cappers; the cappers have an α-carbon bonded to the silicon atom allowing for a favorable hypervalent silicon transition state when reacting the silane and silanol. This favorable transition state enables both a fast endcapping reaction and contributes to the fast moisture curing properties of the inventive compositions.
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FIELD OF THE INVENTION
The present invention relates generally to image capturing, storing, organizing, indexing and retrieving systems and, more particularly, to capturing, storing, organizing, indexing and retrieving images via picture icons and voice activated commands.
BACKGROUND OF THE INVENTION
At present personal pictures are typically stored as prints in albums or “shoe boxes”. Video images are stored on video tape in linear tape formats without any sequence directory. Images, both in still and motion formats, can be stored on Floppy Disks, Photo CD's, Picture CD's, CD-ROM's, Video Tapes, DVD's or similar media. However, video tapes do not provide random access to images, sounds, or video sequences, all of which can be stored thereon and later retrieved from the video tape. Further, CD and DVD recorders do not provide a convenient means to index images, sounds, or video sequences recorded thereon, either as they are recorded or after they are recorded. CD's , DVD's and other Random Access Memory (RAM) devices may provide a sequential “chapter” designation for each start/stop sequence recorded, but these are chronological, numeric designations. There is no current means to index, store, sort, or retrieve images, sounds, or video sequences using orally recorded alpha-numeric designations, graphical icons, or index images during recording of the images, or after images have been recorded. These images can be retrieved and displayed via computer monitors or television sets. At present the retrieval process is necessarily sequential and the organization required to develop a soft or hard copy photo album can be very tedious and time consuming.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an image capturing, storing, indexing, and retrieval system where indexing can be performed both during and after recording of the images.
It is a further object of the present invention is to provide an image capturing, storing, indexing, and retrieval system where audio can be stored and associated with designated images.
Yet another object of the present invention is to provide an image capturing, storing, indexing, and retrieval system where indexing and retrieval of still and/or motion images can be done using key words, picture icon (hereinafter referred to as “picons”) and/or voice activated commands via a device such as a computer with a monitor or DVD recorder/player with television.
Another object of the present invention is to provide an image capturing, storing, indexing, and retrieval system which provides means for associating with each stored image an information file which includes automatically captured and stored metadata as well as user inputted data.
A further object of the present invention is to provide an image capturing, storing, indexing, and retrieval system which allows a user to designate at least one element of the information file associated with an image as an image link.
Still another object of the present invention is to provide an image capturing, storing, indexing, and retrieval system which allows a user to add and edit information files associated with stored images.
Another object of the present invention is to provide an image capturing, storing, indexing, and retrieval system which allows a user to add images to already existing image files, or to add new image files for storage of existing and/or new images therein.
Yet another object of the present invention is to provide an image capturing, storing, indexing, and retrieval system which allows a user to create various image files containing images in a sequence designated by the user.
Briefly stated, the foregoing and numerous features, objects and advantages of the present invention will become readily apparent upon reading of the detailed description, claims and drawings set forth herein. These features, objects and advantages are accomplished by an image storage, indexing and retrieval system in which a plurality of images are storable in digital form on a writeable CD (such as a writeable DVD), each with an associated information file, the associated information file including metadata which has been automatically captured and stored and/or input by a user. Metadata is automatically captured via the camera. The user can also input metadata via the camera at the time of image capture, or via a player/recorder system and its various interfaces when the captured images are added to an interactive database stored in random access memory. Various interfaces allow a user to designate at least one element of the metadata of the associated information file as an image link for each of the image files, and further allows the user to specify more than one of the image links for each of the image files. All of the images having a common image link form a group of images, and the user can determine a sequence of display of all of the digital image files of any group. The user can determine a sequence of display of all of the digital image files associated with a selected image link. An index is created of all of the image links associated with any of the image files and this index is communicated to the user. The user can, via a selected image link, retrieve the group of images having that associated image link with such group of images being retrieved in the sequence determined by the user. The sequence can be preset either at the time the user stores the group in the interactive database, or during subsequent editing of the group of images associated with the selected image link. Retrieval of a group of images can be for purposes of display on a monitor, electronic transmission, editing, copying, and/or printing of hard copies. The user may edit any group of images in the interactive database or add a new group of images to the interactive database at any time, including but not limited to the addition of image files thereto, the subtraction of image files therefrom, the creation and/or designation of new image links. The index can be communicated audibly or by visual display. Preferably, the user can input commands to the camera and/or the player/recorder system via voice actuation, or by tactile input means. A remote interface may also be provided to allow the user even greater flexibility to transmit commands either to the camera or to player/recorder system.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation of the DVD Picon/Imagette/Sound Indexing camera.
FIG. 2 is a side elevation of the DVD Picon/Imagette/Sound Indexing camera.
FIG. 3 is a rear elevation of the DVD Picon/Imagette/Sound Indexing camera in combination with a writeable DVD.
FIG. 4 is a schematic showing the DVD player with control and memory, the monitor, a DVD disk, and a set of speakers.
FIG. 5 is a schematic front elevation view of the remote.
FIG. 6 depicts exemplary symbols (icons).
FIG. 7 is a schematic showing the interactive albuming system where by uttering a key word, all the images associated with the key word are shown as “thumb nail” images in index format on the monitor.
FIG. 8 is a schematic showing the interactive albuming system of FIG. 7 wherein further sorting of the thumb nail images is accomplished by uttering additional key word(s).
FIG. 9 is a schematic showing the interactive albuming system of FIG. 8 wherein still further sorting of the thumb nail images is accomplished by uttering additional key word(s).
FIG. 10 is a schematic showing the interactive albuming system of FIG. 9 wherein still further sorting of the thumb nail images is accomplished by uttering additional key word(s).
FIG. 11 is a schematic showing the interactive albuming system of FIG. 9 wherein individual images can be viewed by uttering key word(s) which would also play any audio file associated with that image file.
FIG. 12 is a flow chart showing the logic of how the master directories and image files are created in the DVD Picon/Imagette/Sound Indexing camera.
FIG. 13 a logic diagram of how the images index and files are created using the DVD voice actuated image and audio albuming system.
FIG. 14 depicts a logic diagram for the operation of the interactive remote control.
FIG. 15 is a schematic representation of the file structure of the master index directory and file of the DVD voice actuated image and audio albuming system.
FIG. 16 is a schematic representation of the master index—directory stored in the memory and control unit of the DVD voice actuated image and audio albuming system and how the master—index directory is updated and displayed.
DETAILED DESCRIPTION OF THE INVENTION
Turning first to FIGS. 1 through 3 there is shown an indexing camera 10 which includes both primary image storage on a disk 16 and secondary picture index storage such as on RAM (not shown). The DVD indexing camera 10 includes stereo microphones 12 which can be used to record sounds from the scene, or to record oral commands from the user. U.S. Pat. No. 5,546,146 to Bernardi et al., entitled Camera On-Board Voice Recognition, describes how a voice activated camera functions and is hereby incorporated herein by reference. Images are recorded through lens 14 and are stored on Digital Video Disk 16 which is inserted into the camera 10 through the DVD access slot 18 . Primary image storage is captured on removable media. Various types of removable media are available such as, for example, magnetics on film (MOF), RAM, optical discs, digital tape, and the like. Preferably, the storage media used is a random accessible storage memory such as: magnetic or optical disks. However, today's linear digital tape storage can also be used. The secondary storage or picture index memory is best done with Flash RAM. The camera 10 is operated using a mode selector switch 20 . In addition, the back side of the camera includes a touch screen 22 with the touch screen operation controls 24 and touch screen indexing controls 26 . Camera 10 further includes a record/capture button 28 . There is an optical viewfinder 30 which is used for framing the scene the user wishes to capture. Touch screen 22 may also be used as a viewer to frame a scene, either alone or in conjunction with optical viewfinder 30 . The touch screen 22 may also be used to select a thumbnail image (Picon) to review the previously recorded still or motion images, as well as to control camera operation or indexing functions. There is a speaker 32 which can be used to hear previously recorded sounds, to verify verbal commands issued by the user, or to provide sound or verbal instructions to the user. The touch screen display 22 can be used to view Picons 23 or Icons 34 . A user can index a video sequence, a still image (photo), or grouping of still images by the use of representative Picons 23 , designated Icons 34 , or verbal references. Picons 23 and oral indices can be established prior to or after images are recorded. Picons 23 may be the first image recorded in a video sequence or a lower resolution version of a recorded still image. Other pre-recorded Picons 23 or Icons 34 may be used in place of those (Picons or Icons) taken from the actual scene.
The camera 10 provides automatically recorded information (automatically recorded metadata) associated with each still image or recording sequence, and manually recorded information (manually recorded metadata) initiated, by the user. Images recorded by the user or pre-stored graphics may be used as Picons or icons, respectively, for storage and retrieval of information or for custom editing the presentation sequence of the recorded sequences or still images. Automatically recorded metadata may include things such as, for example, index pointers to images, time, date, GPS location (associated place), attitude, altitude, direction, exposure settings (aperture/shutter speed), illuminate (daylight/tungsten/florescent/IR/flash), lens setting (distance/zoom position/macro), sound volume/frequency, scene data (blue sky/water/grass/faces), and subject motion. The user also has the option of manually designating metadata to be added such as; scene length, event length, time frame (within the hour, today, this week), record mode (motion/still/burst), and user a designations (text, image, or verbal designation). The camera, if employed in a video mode, may include a scene change detection algorithm which automatically detects when the scene being shot changes, captures a still image associated with the beginning of the scene change and records this as a small version thumbnail or Picon to a portion of RAM designated for visual index information. The second(s) of associated sound bytes and metadata, and image file address pointers of the corresponding image sequence are also recorded. The camera 10 when used to capture an event may also allow through software, for the operator to indicate a particular point in the shooting where a still image for indexing purposes should be captured. It also will index still images when in the still image mode and can automatically sequence the remaining stills for story telling applications until the end of sequence is pushed or the camera shuts down. These operator designated index images (Picons 23 ) with associated sound bytes and metadata are also recorded to RAM and added to the visual scene index directory. The camera 10 employs a mode to interactively link new images or motion sequences by displaying the pre-stored camera master picture directory on the camera LCD. Upon selecting the desired master index thumbnail, the new images and thumbnails will be added to this picture directory sequence path thus evolving the hierarchical picture directory. The sound bytes and metadata are also linked. A new master or sub directory picture thumbnail image—Picon can be generated or an existing thumbnail can be substituted by another image at any time. The master index directory is saved to the camera flash memory. This can be on a fixed or removable RAM disk or card. These master directories can be interchanged to represent a new story telling theme. The master picture directory can be independent from the primary storage media, and it has the disc ID and address pointers for all the indexed sequences. Each image or sequence of motion video contain these pointers to the image directory. The primary picture storage media may also contain a copy of this master index as well.
The camera 10 described above is the preferred embodiment, but the same type of metadata could be captured using an Advanced Photo System camera or other format film camera and magnetics on film, any format film camera equipped with an electronic chip on the magazine or cassette, or an electronic camera memory. A photofinisher receiving film can arrange and write the images onto a DVD disk, Picture CD, or other type of memory such as a Iomega removable hard drive using the methods described in U.S. patent application Ser. No. 09/031,173, Photofinishing Method for Automated Advanced Services Including Image and Associated Audio Data Processing, U.S. Pat. No. 6,147,742, which is hereby incorporated herein by reference.
Turning next to FIG. 4 there is shown a system 35 incorporating a corresponding player/recorder 36 extendible to a multiple disc environment such as a jukebox (not shown), an interactive remote control 38 (see FIG. 5) and a controller with software (not shown) to execute the index and/or retrieval commands of a user. The process runs under CPU control with associated indexing and retrieval applications as employed in computer operating systems. System 35 is a DVD voice actuated image and audio albuming system for storing images on a device such as a DVD disk 40 , filing the images so they are linked to key words or phrases, retrieving the image(s) and associated sound by voice command using a microphone 42 located on the remote control 38 , and viewing the images on a monitor 44 such as a television and hearing the audio via the speakers 46 as the DVD disk 40 is played on the DVD player/recorder 36 with a control and memory (not shown). DVD disk 40 is insertable into system 35 via slot 45 . System 35 may also have associated therewith a flash card reader 48 . The interactive remote control 38 preferably interfaces with system 35 via IR transmission through IR transceiver 50 . A menu bar 52 may also be displayed on monitor 44 . Also displayed on monitor 44 are icons 54 key word symbol 56 with associated key words 58 .
Referring to FIG. 5, the DVD remote control 38 with microphone 42 also has a display 60 . An example of a voice activated remote is a MAGNAVOX Smarttalk VP 8000 VCR Voice Programmer. The remote control 38 is used during and after recording and during viewing, to retrieve images, to selectively edit, arrange sequences and through use of microphone 42 , for audio recording, sound annotation, or verbal operational instructions. For those skilled in the art, an example of voice activation software is IBM's “Via Voice”. The remote control 38 is equipped with manual control buttons 62 that work interactively with the DVD recorder/player system 35 and storage media 40 . The display 60 can be a LCD touch screen display that allows the operator to carry out any of the functions listed above. Remote control 38 also includes an IR transceiver 64 for communicating with system 35 .
Now referring to FIG. 6, the icons 54 (as referenced previously in FIG. 4) indicate what types of files are associated with the image(s) shown on the monitor 44 . The meanings of the icons 54 are, for example, a story 66 , audio 68 , music 70 , additional images 72 , keywords 74 which indicates that there are keywords associated with the image, motion 76 , video snippet 78 , and pages of master index images Picons 80 associated with the picture shown on the monitor 44 . Additional icons 54 representing other features can be created in the same manner icons are created using a computer. Icons 54 can also be created from Picons 80 selected to represent picture sequences such as from a vacation, birthday, special event, or anything the user would like them to represent.
Now referring to FIG. 7 there is depicted a schematic showing DVD-voice actuated image and audio albuming system 35 where by saying, for example, the word “grandma”, all the images 82 associated with a “grandma” (which can include a Grandma X, a Grandma Y and a Grandma Z, for example, as are depicted) are shown as “thumb nails” images in index format on the monitor 44 .
Turning to FIG. 8, the thumb nail images 23 can then be further sorted by using additional words spoken orally such as, for example, “Grandma X.” Then, in response to those spoken words, only those pictures 84 of Grandma X (if they have been indexed with that word) would appear on the monitor 44 .
Looking at FIG. 9, the thumb nail images 23 can then be further sorted by using additional words (again spoken orally) such as Grandma X and Aunt Y. All images 86 showing Grandma X and/or Aunt Y would then appear on monitor 44 .
The images can be sorted further by adding more key words such as “Grandma X at her cabin the Ozark Mountains”. All images 88 showing Grandma X at her cabin in the Ozark Mountains would then appear on monitor 44 as shown in FIG. 10 (assuming the images had been indexed with such key words).
As shown in FIG. 11, by saying the word “singing” for example, all the images associated with a grandma singing and the associated audio files will be shown as image(s) 90 on monitor 44 . By selecting a specific image, the associated audio file would be played. These can then be further sorted be using additional words such as, for example, Grandma X singing Christmas carols. Then only pictures of Grandma X in which she was singing a Christmas carol would appear.
Referring to FIG. 12, a flow chart is presented showing how the master directories and image files are created in the DVD Picon/Imagette/Sound Indexing camera 10 . The user captures an image (still) or images (motion sequence) as indicated in function block 92 and records the associated metadata as indicated in function block 94 . If the camera 10 does not have the preference selected (decision block 96 ), the user can choose to select what metadata he or she prefers, for example, time and date as indicated by function block 98 . If the preference has been set,that is, the answer to decision block 96 was “yes”, the user chooses whether or not to have the camera automatically tag and index (decision block 100 ). If the answer is “no” the user can choose to tag and file the captured image using metadata from the camera (decision block 102 ). If the answer to decision block 102 is “no” the user can choose to input the metadata manually (decision block 104 ). If the answer to decision block 104 is “no” the user can choose not to provide metadata (as indicated by function block 106 ). If the answer to decision block 100 is “yes” the images captured are automatically tagged by the camera 10 using the associated metadata to create an index (as indicated by function block 108 ) and are filed in camera memory, for example DVD disk 16 of FIG. 3 (as indicated by function block 110 ). If the answer to decision blocks 102 or 104 are “yes” the images captured are automatically tagged with the selected metadata and are filed in camera memory (as indicated by function block 110 ). The sequential images will be tagged with the metadata until the camera power is turned off.
Now referring to FIG. 13, there is graphically presented a logic diagram of how the images' index and files are created using DVD voice actuated image and audio albuming system 35 . A disk 40 containing digital image files is loaded into the player/recorder 36 per function block 112 . The user selects an image (for example, image 57 shown in FIG. 4) per function block 113 . The memory and control unit 47 of the player/recorder determines if the selected image has been previously filed and indexed per decision block 114 . If the answer to decision block 114 is “yes”, that is, the image has been filed and indexed, the image will appear on the monitor 44 in index format as indicated by function block 116 . If the image has not been previously filed and indexed (the answer is “no”), the first image on the disk will appear on the monitor and the user can decide if he wants to create a file and an index per decision block 118 . If the answer is “no”, the user simply views the image 57 on the monitor 44 as indicated by function block 120 and advances to the next image. If the answer is “yes”, the memory and control unit 47 determines if there is metadata from the camera 10 per decision block 122 . If the answer to decision block 122 is “yes”, the metadata from the camera 10 is loaded into the memory and control device 47 as indicated by function block 124 . The metadata may be loaded via a device such as a flash card reader 48 , DVD disk 40 , or from metadata that has previously been transferred into the memory and control unit 47 . If the answer to decision block 122 is “no”, the user is asked if he would like to enter additional metadata using the interactive remote control 38 per decision block 126 . If the answer is “yes”, the user inputs new metadata using the interactive remote control 38 per function block 128 , i.e. attaches a keyword such as “grandma” to the displayed image 57 . If the answer is “no”, the user then is asked to select metadata (per decision block 130 ) from capture i.e. date and time recorded by the camera. If the answer to decision block 130 is “no”, the user views the image. If the answer is “yes”, the user selects the specific metadata and the metadata is linked or tagged to the displayed image 57 per function block 132 . The process is then repeated for additional images until the user has finished per decision block 134 filing and indexing the images.
Now referring to FIG. 14 there is depicted a logic diagram of the operation of the interactive remote control 38 . A user can decide to control the DVD-voice actuated image and audio albuming system 35 using the remote 38 per decision block 136 . If the user decides to use voice activation, a command can be orally entered per function block 138 . If the user decides not to use voice activation, the user can use the control buttons 62 or the display 60 which can be an LCD touch screen to retrieve an image 57 or an image index 140 (see FIG. 15) per decision block 142 to enter the appropriate commands as shown by function block 144 . In this manner, the user selects an image 57 or an image index 140 to view as indicated by function block 146 . The user can now choose to edit, arrange, or add metadata to the displayed image 57 or image index 140 per decision block 148 by entering the appropriate command per function block 150 . Alternatively, the user can just view the image per function block 152 . The user can then choose to go to the next image index 140 or image 57 or can choose to stop per decision block 154 .
Now referring to FIG. 15, there is shown a schematic of the file structure of the master index directory and file 156 of the DVD voice actuated image and audio albuming system 35 . When the user selects an image 158 to be used to represent a group of images 160 , the selected image 158 becomes a Picon which represents the linked group of images 160 . Linking is accomplished using selected metadata. In the case of images 160 containing Grandma X, the metadata used is a subject in the image, namely Grandma X. The image 158 selected then becomes the Picon 158 for the group of images 160 containing Grandma X. Similarly, other images can be selected to become Picons 162 , 164 , 166 , for other groups of images 168 , 170 , 172 again using any selected metadata. For example, image 162 of the Rocky Mountains can be chosen to be the Picon 162 for a family's summer vacation to the Western U.S. in 1997 where the group of images 168 are linked via the selected metadata under the subject of the family's 1997 summer vacation. The selected metadata is an event where all the images have been captured while the family was on vacation. All the images of the family's 1997 summer vacation 168 are tagged and filed together using the Rocky Mountain Image 162 as the Picon. As an example of using a date as the selected metadata images 170 are all images taken on a specific date which have been tagged using the selected metadata such as the date August 1998. The image 164 of the car and house can be chosen as the Picon 164 and all images tagged and filed using that date as the selected metadata are linked as the group of images 170 . As yet another example, the selected metadata can be a specific location. An image 166 such as a group of houses can be selected as the Picon 166 for a group of images 172 taken at that location where the selected linking metadata is a specific location.
Now referring to FIG. 16 there is schematically represented a master index—directory 156 stored in the memory and control unit 47 of the DVD voice actuated image and audio albuming system 35 . A master index directory 156 is created using the steps described in FIG. 15. A master index directory 156 can also be created in a capture device such as the DVD Picon/Imagette/Sound Indexing camera 10 described in FIGS. 1, 2 and 3 . If created in a camera 10 , the master index directory 156 is down loaded into the memory and control unit 47 per function block 176 . The downloaded master index directory 156 where the existing master index directory is updated per function block 178 . The master index directory 156 is displayed as array of image Picons 180 with each Picon being linked to a stored group of images, for example, groups of images 160 , 166 , 168 , 170 . Additional images can be loaded into of the DVD voice actuated image and audio albuming system 35 via a Digital Video Disk 40 per function block 182 or a DVD Jukebox per function block 184 . When an image(s) 57 that has not been entered in to the master index directory 156 are loaded, the image(s) appear in index format on the monitor 44 . The user then follows the steps described in FIG. 13 to file and index the selected image(s) 57 . The master directory 156 consists of Picons which represent a plurality of images grouped together under a common theme i.e. Grandma X, as described with reference to FIG. 15 . The user can then select each image using the remote control 38 as shown by function block 186 . The chosen image 57 is displayed on the monitor 44 . Picons are created by selecting a specific image to represent a group of images as described with reference to FIG. 15, i.e. a specific image 158 of Grandma X can be used to create a Picon 158 that will appear as a representation in the master directory for all the images filed under the selected metadata, Grandma X. When the Picon 158 is addressed, the group of images 160 filed under that Picon 158 appear on the monitor 44 with the Picon 158 appearing in the corner. If the master index directory 156 is called up, the screen will show all the Picons of all of the groups of filed images.
It should be understood that provision is made in the player/recorder system 36 , and/or in the camera 10 to edit the selection of index images 23 , 34 . In this mode, index images 23 , 34 could be deleted from the index file and additional ones added as the index file and disc contents can be reviewed. This procedure gives the user the ability to do a custom rearrangement of a sequence of images for story telling. The DVD player/recorder 36 can also be used to alter the playback sequence or hide motion sequences or stills as noted in player memory and update the master picture directory.
From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are apparent and which are inherent to the invention.
It will be understood that certain features and subcombinations are of utility and may be employed with reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth and shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST
10
camera
12
microphones
14
lens
16
Digital Video Disk (DVD)
18
access slot
20
mode selector switch
22
touch screen
23
thumb nail images (picons)
24
touch screen operation controls
26
touch screen indexing controls
28
record/capture button
30
view finder
32
speaker
34
icons
35
DVD voice actuated image & audio
albuming system
36
player recorder
38
interactive remote control
40
random access storage device
42
microphone
44
monitor
45
access slot
46
speakers
47
memory & control
48
flash card reader
50
IR transceiver
52
menu bar
54
icons
56
keyword symbol
57
first image
58
associated keywords
60
display
62
manual control buttons
64
IR transceiver
66
story
68
audio
70
music
72
additional images
74
key words
76
motion
78
video snippet
80
picons
83
grandma images
84
pictures of grandma X
86,88,90
images
92,94
function block
96,100,102,104,114,118,122
decision block
126,130,134,136,142,148,154
decision block
98,106,108,110,112,113,116
function block
120,124,128,132,138,144
function block
146,150,152,176,178,182,184,186
function block
140
image index
156
structure & file
158
image/picon
162,164,166
image/picon
160,168,170,172,174
groups of images
180
array of image picons
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An image storage, indexing and retrieval system is disclosed in which a plurality of images are storable in digital form (on a writeable DVD), each with an associated information file, the associated information file including metadata which has been automatically captured and stored and/or input by a user. Metadata is automatically captured via the camera. The user can also input metadata via the camera at the time of image capture, or via a player/recorder system and its various interfaces when the captured images are added to an interactive database stored in random access memory. The user may designate one or more elements of the metadata of the associated information file as an image link for each of the image files, and further the user may specify more than one image links for each of the image files. All of the images having a common image link form a group of images, and the user can determine a sequence of display of all of the digital image files any group. An index is created of all of the image links associated with any of the image files and this index is communicated to the user. The user can, via a selected image link, retrieve the group of images having that associated image link with such group of images being retrieved in the sequence predetermined by the user. The sequence can be preset either at the time the user stores the group in the interactive database, or during subsequent editing of the group of images associated with the selected image link. The index can be communicated audibly or by visual display.
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BACKGROUND OF THE INVENTION
Electronic organs have been known for many years and for most of the that time have used analog tone generators of one sort or another. In so called additive or synthesizing organs it has been the practice to add together a large number of harmonically related sine waves to produce resultant complex waves. In the so called formant type of organ complex waves have been generated which have thereafter been filtered to remove undesired harmonic and inharmonic partials, and thereby to simulate a desired wave form.
In more recent years the patent art is replete with disclosures of digital organs in which computer techniques are utilized to generate or establish desired wave forms.
SUMMARY AND OBJECTS OF THE PRESENT INVENTION
It is known that a square wave with a 50% duty cycle produces only the odd harmonics. It is also known that a rectangular wave with a one-eighth duty cycle produces a tone simulating a piano. It readily follows that different duty cycles produce different harmonic structures and output tones. It can be demonstrated mathematically that any desired wave form can be developed from a rectangular or pulse wave by varying the start and the duration or each pulse in a plurality of fixed positions per cycle. It is an object of this invention to utilize this knowledge in a practical structure for producing a desired wave shape.
In particular, it is an object of this invention to provide means for generating a pulse train having a variable number of pulses per cycle, and with means for varying the starting time and duration of the pulses in accordance with a predetermined pattern to produce a desired time varying harmonic content.
Specifically, in connection with the present invention a pulse train as set forth heretofore is generated in which binary related numbers are fed in parallel and are combined with a read only memory and an adder to a comparator for varying the starting time and the duration of pulses in each cycle in accordance with the information stored in the read only memory.
DRAWING DESCRIPTION
The invention will best be understood with reference to the following text and accompanying drawings wherein:
FIG. 1 is a block diagram of an electronic musical instrument constructed in accordance with the present invention;
FIG. 2 shows the basic pulse pattern produced in accordance with the present invention;
FIG. 3 comprises a block diagram of the pulse producing system of the present invention;
FIG. 4 is a wave form of an exemplary frequency at the start of generation of such frequency;
FIG. 5 is similar to FIG. 4 but showing the same note for example at the end of the time variation period;
FIG. 6 comprises a primarily block diagram illustrating the useage of a common counter to develop blocks of N-bit numbers for use by the control circuits of each octave;
FIG. 7 is a simplified portion of the ROM and the counter advance and divisors for control of the ROM;
FIG. 8 shows a simplified example of pulse formation vs. master clock frequency;
FIGS. 9 and 10 are block diagrams showing further control of the time variation of spectral content of the pulse wave developed in accordance with the present invention and
FIG. 11 is a block diagram showing a variation in which a time varying spectral content is to be used for only a portion of the note play length.
DETAILED DESCRIPTION
Referring now in greater particularity to the drawings, and first to FIG. 1, there will be seen a block diagram of an electronic musical instrument generally designated 20. This musical instrument includes a plurality of key switches 22. In the case of an electronic organ it will be understood that the key switches also generally include switches to be operated by the feet through the use of pedals or pedal keys. In the present invention the harmonic structure is designed to change markedly with time, and this particularly exemplifies the tone of a piano. A piano, of course, conventionally has only one keyboard rather than the two keyboards and pedalboard of an organ. The key switches 22 are in turn respectively suitably connected to tone generators 24 incorporating the novel aspects of the present invention. Tone generators are connected to an amplifier 26, and this in turn is connected to a loudspeaker 28 for converting electronic oscillations into audible sound.
For the sake of exemplification of the present invention a wave form 30 (FIG. 2) comprises four pulses to one cycle of the wave form. The frequency of each note is of course determined by the duration of a cycle. In the present instance the harmonic structure of the wave form is determined by the time that each pulse starts within a cycle, and also the duration or length of the pulse.
In the example given in FIG. 2 there are four pulses per wave form. The pulses are produced by alternate transitions from 0 to 1 and from 1 to 0. Hence, there are 8 transitions and 8 sections to the pulse pattern respectively denoted by P 1 through P 8 , respectively.
Attention now should be directed to FIG. 3 which comprises a block diagram of the pulse producing system for one note, there being one such system for each note. This system has similarities with copending application Ser. No. 758,598 filed Jan. 12, 1977 by Robert W. Wheelwright and Peter E. Solender, now U.S. Pat. No. 4,137,810 entitled "Digitally Encoded Top Octave Generator" and assigned to the same assignee as the present application, namely The Wurlitzer Company. That disclosure is incorporated herein by reference. Eight related binary counter outputs are supplied in parallel at 32 from a counter. The source of these binary numbers will be set forth in some detail later. Note that at any given instant of time the eight counter outputs are an eight-bit number, but in on going time they are also frequencies, and these frequencies, as shown in FIG. 3 comprise f, f/2, f/4, f/8, f/16, f/32, f/64 and f/128.
The eight binary related frequencies are applied to an eight bit buffer/latch 34 which has eight parallel outputs at 36 entered into an eight bit adder 38. The purpose of this latch is to "freeze" the on going frequencies at some defined point as an 8-bit word.
The circuit also includes a 256×8 bit ROM (read only memory) 40 which provides an 8 bit binary word output, i.e., 8 parallel binary outputs at 41 to the 8 bit adder 38. The binary number from the ROM specifies the increment (or time interval) before the next transition of the wave form. (These increments correspond to the time periods P 1 -P 8 in FIG. 2 and are equal to the stored number.) The sum of these increments must total the period of one cycle of the note frequency. Thus f out=(P 1 +P 2 +P 3 + . . . +P n )/f.
Control for the ROM is provided by a divide-by-eight circuit 42 having the final output thereof fed at 43 to a divide-by-thirty-two circuit 44. (It will be appreciated that each of the blocks or black boxes in FIG. 3 comprises a commercially available integrated circuit chip, and exemplary types will be set forth hereinafter.) The three outputs of the divide-by-eight circuit identified in common by numeral 46 are connected to appropriate input terminals of the ROM 40. Similarly, the five outputs 48 of the divide-by-thirty-two circuits 44 are connected to respective appropriate inputs of the ROM 40.
The eight binary related frequencies at 32 are applied in parallel also at 50 to an eight bit comparator 52. An eight-bit number output from the eight bit adder 38 is applied at 54 to a second input of the eight bit comparator 52. The eight bit comparator is provided with an output line 56 which has a high or logical one output when the inputs 50 and 54 are identical. The output line is connected to an AND gate 58 having a clock input 60 at 2f. The 2f clock pulse is synchronous with the binary related frequencies and provides half-clock strobing of the various control elements. The AND gate has an output 62 which leads through a line 64 to the eight bit buffer/latch 34 to load the buffer when there is a one output from the AND gate. The output line 62 from the AND gate also is connected through an additional line 66 to the divide-by-eight circuit 42 to cause the latter to advance and present the next word to the read only memory when there is a one output from the AND gate. In addition, the output line 62 is connected to yet another line 68 leading to the clock or toggle input of a JK flip-flop 70.
An enable line 72 is connected to the reset terminal of the JK flip-flop 70 at 74, and also to the reset terminals 76 and 78 of the divide-by-eight and the divide-by-thirty-two circuits. This line allows the generator to be locked off and enabled (re-started) on command. The Q output of the JK flip-flop 70 comprises a line 80 which is either a one or a zero, depending upon the state of flipping or flopping of the JK flip-flop, the output on the line 80 comprising the desired pulse train output.
When the "present" state of the eight binary related input frequencies is loaded into the eight bit buffer/latch 34 the increment or time interval to the next transition reads from the ROM 40 to produce an output from the adder 38 to the comparator 54. When a comparison is reached the AND gate 58 on the next 2f clock pulse produces an output at 62, whereby the JK flip-flop 70 changes state. At the same time the output from the AND gate 58 at 64 loads in a new "present" state to the eight bit buffer 34. Similarly, the divide-by-eight circuit 42 is moved to its next state by the AND gate output at 66. The divide-by-eight circuit will initially be set to 0 (when the enable is off) and as it goes through its eight states the increments P 1 through P 8 will be produced. The divide-by-thirty-two circuit following the divide-by-eight circuit allows 32 consecutive variations of the eight increments to be produced. This allows the waveform to change with time. It is to be understood that the divide-by-eight and divide-by-thirty-two circuits could be restructured to comprise a divide-by-sixteen and a divide-by-sixteen circuit to produce sixteen variations of an eight pulse train, or a divide-by-thirty-two and a divide-by-eight circuit to produce eight variations of a sixteen pulse train, etc.
The eight related binary frequencies at 32 may be produced by divide-by-sixteen circuits as will be pointed out hereinafter, each such divide-by-sixteen circuit comprising a commercially available 74193 chip. Similarly, the eight bit buffer is a commercially available chip number 8202. The eight bit adder comprises two four bit adders each a commercially available chip number 7483, interconnected in the usual manner to comprise an eight bit adder. The ROM 40 comprises a PROM (programmable read only memory) available commercially as chip number 5202 AQ, while the eight bit comparator 52 comprises two four bit comparator chips number 9324 connected in the usual manner. The AND gate 58 and the JK flip-flop 70 are well-known in the art, but for example may comprise commercial chips 7408 and 7473, respectively.
In order to determine the frequency relationships it must be recognized that at least two transitions are required to make up a frequency waveform. With an eight bit system as described herein there can be up to 256 increments per transition. Thus, the increments sum to a total of 512 increments to produce a frequency or cycle. It is desired for practical reasons to keep the upper frequency as low as possible. If the clock frequency can be held below two MHz the system is PMOS compatable. If 510 is chosen as the upper sum increment and the last octave of the keyboard starts at note 85, then the upper clock frequency can be determined. Note 85 is 3520 Hz in frequency, and the clock frequency therefore is 3520 Hz×510=1.7952 MHz.
Utilizing the aforesaid clock frequency, a chart relating notes 85 to 88 and the summed increments thereof is as follows:
______________________________________Summed Increment Note Number______________________________________510 85481 86454 87429 88______________________________________
If the same concepts are to be followed as to frequencies produced an octave below note 85, the clock frequency must also be reduced by a factor of 2. A corresponding chart showing summed increments for notes 73 to 84 based on a clock frequency of 1.7952/2=897.6 KHz is as follows:
______________________________________Summed Increment Note Number______________________________________510 73481 74454 75429 76405 77382 78361 79340 80321 81303 82286 83270 84______________________________________
The same list of summed increments can be used for each octave by dropping the clock frequency by a factor of two as the octaves go down the scale. A block diagram of a circuit producing all of the clock frequencies and binary frequencies for the 88 note system is shown in FIG. 6. This circuit comprises the clock in at 82, which comprises also the first clock frequency out at 84. The clock frequency at 82 is applied to divide-by-two circuit 86, which produces f 1 at 88. The output of the divide-by-two circuit 86 is also connected to another divide-by-two circuit 90, which is connected to further divide-by-two circuits seratim to a total of 15 divide-by-two circuits, all identical. Clock outputs and the respective frequencies for each octave are provided as shown.
There is one pulse producing system as in FIG. 3 for each frequency to be produced from the electronic musical instrument. The frequency of the clock, f, for the top octave is shown as the f 1 output at 88. The output at 84 comprises the 2×f input at 60 in FIG. 3 for half clock strobing. F2 in the top line (notes 85-88) of FIG. 6 is f/2 of FIG. 3 etc.
Similarly for the second octave, notes 73-84 (second line of FIG. 6.) the f 1 is f of FIG. 3, while f 2 of FIG. 6 is f/2 of FIG. 3, etc.
In FIG. 2 an arbitrary pulse pattern for a single cycle of note frequency is shown. The construction of a particular illustrative note is shown in FIGS. 4 and 5. FIG. 4 illustrates the note at its inception, whereas FIG. 5 shows conclusion of the note after several changes over a period of time.
Specifically, in FIG. 4 there are four pulses shown with the increments for each illustrated. The pulses have been chosen to produce a certain harmonic response. The first pulse width is 113 increments out of a summed total of 454 increments, i.e., approximately a 1/4 duty cycle.
The waveform in FIG. 5 is of the same frequency as FIG. 4, but changed with time as after 20 changes. The increments are stored in the ROM to be read out at different portions of the divide-by-eight decoded states. The first time span pulse remains at 113 increments. However, the second time span has been shortened to only one increment. The next pulse is at seventy increments. The remaining increments can readily be seen in FIG. 5 the same as in FIG. 4, whereby the pulse distribution readily can be seen to be substantially altered, thus resulting in a changed harmonic structure of the note produced, notwithstanding lack of change of the basic frequency of the note. It will be noted that the difference in the wave form is in the second and third pulses, i.e. P 3 and P 5 changing starting points and widening with time. The sequence of variation from FIG. 4 to FIG. 5 can occur in any desired manner. For example one or more pulses could narrow to zero, thus effectively reducing the number of pulses.
If it is desired that the frequencies across the scale should become slightly sharp as the note numbers are increased (scale stretching), the summed increments can be changed slightly. Since the summed increments are contained in read only memories, this is readily done.
Although it is believed that the invention is adequately disclosed up to this point it is felt that additional explanatory material as hereinafter set forth may be helpful. Thus, with reference to the ROM 40 in FIG. 3 and also to the divide-by-eight circuit 42 and the divide-by-thirty-two circuit 44, the output 41 of the ROM comprises data lines presenting an eight bit word for each address. The first three address lines from the divide-by-eight circuit are used to determine the numer of transitions per cycle. In the exemplary embodiment of the invention there are eight transitions per cycle, i.e. four pulses. The five address lines from the divide-by-thirty-two circuit are used to determine the number of variations of pulse width/position.
FIG. 7 is similar to a portion of FIG. 8, but somewhat simplified for illustration. In order that the correspondence in part might readily be evident, corresponding numerals are used with the addition of the suffix a. Thus, the ROM 40a is simplified to be only a 32 word by 5 bit ROM. Similarly, the first divider 42a comprises a divide-by-four circuit, while the second divider 44a comprises a divide-by-eight circuit. Since there are now five bits per word, there are 32 possible increment points for transition. There are also 32 words which means 32 possible transitions. The counter is split to show four transitions per cycle and eight cycle patterns. The following chart shows each of the thirty-two words stored in the ROM word positions. Each word stored tells the interval or number of increments to the next transition. Each interval is up to the thirty-two countes of the master clock. This is any number from 1 to 2 N , where N equals the number of bits per word (in the case N=5). This chart is as follows:
______________________________________ WORD STOREDROM COUNTER STATE (Decimal Base)______________________________________0 00000 201 10000 42 01000 43 11000 44 00100 185 10100 66 01100 47 11100 48 00010 169 10010 810 01010 411 11010 412 00110 1413 10110 814 01110 615 11110 416 00001 1217 10001 818 01001 619 11001 620 00101 1021 10101 822 01101 823 11101 624 00011 825 10011 826 01011 827 11011 828 00111 629 10111 830 01111 1031 11111 8______________________________________
The eight possible cycle patterns from the chart above are shown in FIG. 8. Thus, the main clock waveform is shown at 92. In the first cycle under this waveform we see that the first period is 20 transitions of the main clock, corresponding to "word stored" 20 opposite word zero. There are four counter transitions in the next pulse, followed by two more four counter transitions to complete the first cycle.
The second cycle then takes over with 18 transitions, as corresponds with "word stored" 18 opposite word four in the foregoing chart. The remainder of FIG. 8 is believed to be self-explanatory.
Further control of the time variation of spectral content of the wave is illustrated in FIGS. 9 and 10. In FIG. 9 parts corresponding to the parts of FIG. 3 and 7 are identified by similar numerals with the addition of the suffix b, while in FIG. 10 similar parts have similar numerals with the addition of the suffix c.
FIG. 9 is distinguished in that line 43b leads to a divide-by-eight circuit 94, which in turn is connected by an output line 96 to the previous divide-by-eight circuit 44b . Addition of the divide-by-eight circuit 94 causes production of eight cycles of each type to be played.
FIG. 10 again is similar, with line 43c leading to a one shot circuit 94c of t seconds duration. The output from the one shot 94c leads through a line 96c of the divide-by-eight circuit 44c. This produces t seconds of each type cycle to be played. In other words, in FIG. 9 the repetition of a cycle continues for eight cycles regardless of time and is synchronous while in FIG. 10 each cycle is continued for t seconds regardless of how many repetitions this may comprise and is asynchronous.
Further control is shown in FIG. 11, various parts again corresponding to FIG. 7, and similar numerals being used, this time with the addition of the suffix d.
FIG. 11 distinguishing features includes more substitution of an OR gate 98, with the lead 43d comprising one input to the OR gate. A 3-input AND gate 100 has its input connected to the lines 48d. When all three of the inputs are high the AND gate 100 has a one output which is connected through a line 102 to the second input of the OR gate 98. In this circuit the time varying spectral content is used for only a portion of the note play length. Thus, the OR gate 98 serves as a blocking gate for the second portion of the ROM counter. In the circuit of FIG. 11 there is a time variation of harmonics followed by a long sustain on, for example, the eighth pattern. The divide-by-eight 44d locks on the last pattern until reset. The output of the OR gate 98 stops high and the divide-by-eight circuit 44d will not advance except on a negative during transition. As is known, typical TTL counters trigger on the negative edge, while CMOS circuits trigger in the positive going edge.
The foregoing specific examples of the invention are by way of illustration only. Various changes in structure will no doubt occur to those skilled in the art, and will be understood as forming a part of the present invention insofar as they fall within the spirit and scope of the appended claims.
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An electronic musical instrument develops digital pulses corresponding to electronic waves that are subsequently converted to audio sound such as by means of a loudspeaker. The musical instrument is provided a source of master frequency generated binary related numbers which act in conjunction with a read only memory, an adder, and a comparator, and also a counter, to control a J/K flip-flop to produce a pulse train output in which for any given cycle the starting time and duration of each pulse is controlled, thereby to determine the harmonic content of the electronic waves that are converted to audio sound.
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BACKGROUND
1. Field
This patent specification describes a sheet elevation apparatus for use in an image forming apparatus, and more particularly to a sheet elevation apparatus capable of being coupled to an image forming apparatus with a more easy-to-use manner. This patent specification further describes an image forming apparatus using the above-mentioned sheet elevation apparatus.
2. Discussion of the Background Art
Background image forming apparatuses such as copiers, facsimiles, and printers have been provided with a sheet supply box for containing a stock of recording sheets. A typical example of the sheet supply box is called a sheet tray cassette which is detachably mounted to an image forming apparatus. Some sheet tray cassettes include a sheet elevating mechanism for elevating a stock of recording sheets placed on a base plate upwardly in accordance with an amount of recording sheets remaining on the base plate. With this mechanism, an uppermost recording sheet of the stock of recording sheets placed on the base plate is kept at a predetermined position suitable for being picked up for a transportation to an image forming operation.
In responding to an increasing demand for a high-volume reproduction, a recent sheet tray cassette has a relatively large capacity and needs a relatively great driving power for elevation of the base plate. In addition, a so-called front-loading is a current mainstream of the sheet tray cassette, capable of being loaded into an image forming apparatus from a front position, that is, an operator's position. The front-loading sheet tray cassette is typically provided with a coupling to engage an elevator with a drive motor. When the sheet tray cassette is pulled out, the coupling disengages the elevator from the drive motor which is left in the apparatus.
In one example coupling mechanism, a joint which forms a coupling at the drive motor side is movable in an axis direction by a predetermined stroke and has an edge surface having a cross-shaped groove formed in a direction perpendicular to the axis. A counter member forming the coupling together with the joint has a top surface forming a cross-shaped pin. The cross-shaped pin of the counter member is inserted to the cross-shaped groove of the joint so that a power of the drive motor is transmitted.
The above-mentioned joint is pressed toward the counter member in the axis direction with a spring. The cross-shaped pin and the cross-shaped groove may not always conveniently be met with each other for an appropriate engagement during a loading of the sheet tray cassette into the image forming apparatus. When the cross-shaped pin and the cross-shaped groove are not properly met and are not engaged with each other, the counter member pushes the joint in a direction opposing the force of the spring. As the joint is moved in the direction opposing the force of the spring, a relative position of the joint and the counter member is gradually changed. When the relative position of the joint and the counter member is changed to an engagement position, the cross-shaped pin of the counter member is inserted into the cross-shaped groove of the joint. Thereby, an engagement of the coupling is achieved.
The background image forming apparatus is also provided with a pair of rails on which the sheet tray cassette is slid when it is loaded. Loading the sheet tray cassette is not so easy because of weights of recording sheets and the sheet tray cassette itself. Loading the sheet tray cassette also needs a counter power to oppose the force of the spring associated with the joint.
As such, elevating the base plate needs a relatively great power, and the coupling may easily be disengaged if the engagement of the coupling is insufficient. As a result, a the base plate falls down about a fulcrum. To address this problem, a solution may be to make the moving stroke of the joint and the force of the spring both greater. Accordingly, a more greater force for pushing the sheet tray cassette is needed.
In the above case, the sheet tray cassette continues to receive a force in a direction to be pushed out due to a reaction force generated by the spring until an engagement of the coupling is completed. That is, an extra holder may be needed for holding the sheet tray cassette against the reaction force.
SUMMARY
This patent specification describes a novel sheet elevating apparatus for use in a sheet tray cassette detachably installable to an image forming apparatus. In one example, a novel sheet elevating apparatus includes an elevation driving source, a first coupling, an elevation member, a second coupling, and an elevation controller. The elevation driving source is mounted to the image forming apparatus. The first coupling is connected to the elevation driving source and has a home position. The elevation member is configured to elevate a plurality of recording sheets placed on an elevating base plate of the sheet tray cassette. The second coupling is connected to the elevation member and is configured to be engaged with the first coupling set at the home position when the sheet tray cassette is installed in the image forming apparatus. The elevation controller is configured to drive the elevation driving source to set the first coupling to the home position when the sheet tray cassette is pulled out.
This patent specification further describes a novel image forming apparatus with an improved superior sheet elevating mechanism. In one example, a novel image forming apparatus includes an image forming mechanism and a sheet tray cassette. The image forming mechanism is configured to form an image. The sheet tray cassette includes an elevating base plate and a sheet elevating device. On the elevating base plate, a plurality of recording sheet are placed, and the plurality of recording sheets are picked up sheet by sheet and are transported to the image forming mechanism to receive the image thereon. The sheet elevating device has an elevation driving source, a first coupling, an elevation member, a second coupling, and an elevation controller. The elevation driving source is mounted to the image forming apparatus. The first coupling is connected to the elevation driving source and has a home position. The elevation member is configured to elevate the elevating base plate of the sheet tray cassette to lift the plurality of recording sheets placed thereon. The second coupling is connected to the elevation member and is configured to be engaged with the first coupling set at the home position when the sheet tray cassette is installed in the image forming apparatus. The elevation controller is configured to drive the elevation driving source to set the first coupling to the home position when the sheet tray cassette is pulled out.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is an illustration of an image forming apparatus according an example embodiment;
FIG. 2 is an illustration of a sheet elevation device of the image forming apparatus illustrated in FIG. 1 ;
FIG. 3 is a flowchart of an example procedure of a warning indication conducted by the sheet elevation device of FIG. 2 ;
FIG. 4 is an illustration of an example remaining sheet detecting mechanism included in the sheet elevation device of FIG. 2 ;
FIG. 5 is a flowchart of an example procedure for quickly returning a coupling to a home position; and
FIG. 6 is a flowchart of an example procedure for avoiding a damage by returning the coupling to the home position while the coupling is engaged.
DETAILED DESCRIPTION OF EMBODIMENTS
In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner. Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, particularly to FIG. 1 , an image forming apparatus 1 according to an example embodiment of the present invention is described.
As illustrated in FIG. 1 , the image forming apparatus 1 includes a sheet tray cassette 2 , an elevation motor unit 10 , a pick-up roller 15 , a transport roller 16 , a reverse roller 17 , pairs of rollers 24 and 25 , and a pair of registration rollers 26 . The image forming apparatus 1 further includes a photosensitive drum 27 , a charging unit 28 , an optical writing unit 29 , a development unit 30 , a transfer roller 31 , a cleaning unit 32 , a fixing unit 33 , a pair of transport rollers 34 , a pair of face-up ejection rollers 35 , a waist level ejection tray 36 , an image reading unit 37 , a transportation belt 40 , and a pair of straight ejection rollers 360 .
As illustrated in FIG. 1 , the image forming apparatus 1 has a vertical structure in which the image reading unit 37 , the waist level ejection tray 36 , an image forming mechanism centered with the photosensitive drum 27 , and a sheet supply mechanism centered with the sheet tray cassette 2 are, in this order, vertically mounted.
In the image forming mechanism, the photosensitive drum 27 is surrounded by a variety of process components according to manners of an electrostatic recording method, including the charging unit 28 , the optical writing unit 29 , the development unit 30 , the transfer roller 31 , and the cleaning unit 32 .
The photosensitive drum 27 has a cylindrical, rotary, photosensitive surface. The charging unit 28 charges this photosensitive surface while the photosensitive drum 27 is rotated. The optical writing unit 29 generates exposure light and irradiates the charge surface of the photosensitive drum 27 with the exposure light. The optical writing unit 29 extends the exposure light within a predetermined imaging area on the photosensitive surface of the photosensitive drum 27 according to an original image read by the image reading unit 37 . As a result of exposure, an electrostatic latent image is formed on the photosensitive surface of the photosensitive drum 27 . The thus-formed electrostatic latent image is brought forward as the photosensitive drum 27 is rotated, and is visualized with toner by the development unit 30 when passing by a development area formed by the development unit 30 . A resultant image after development is referred to as a toner image. The photosensitive drum 27 is further rotated and the toner image is brought to a transfer point where the toner image meets with a recording sheet P and is transferred onto the recording sheet P by the transfer roller 31 . This image transfer is caused by an action of a transfer bias voltage applied to the transfer roller 31 . The recording sheet P is transported from the sheet tray cassette 2 and is stopped by the pair of registration rollers 26 . Driving the pair of registration rollers 26 is in synchronism with timing data from the optical writing unit 29 , and the pair of registration rollers 26 are restarted to driven so that the recording sheet P is transported to the transfer point in synchronism with the rotation of the toner image carried on the photosensitive drum 27 . At the transfer point, the toner image is transferred onto the recording sheet P by the transfer bias voltage applied to the transfer roller 31 .
The transfer roller 31 is also used as a supporting roller of the transportation belt 40 . After the transfer process described above, the recording sheet P having the toner image thereon is further transported by the rotation of the transportation belt 40 and is subjected to a fixing process when passing through the fixing unit 33 . The recording sheet P after exiting the fixing unit 33 is further transported in a course of either a straight ejection or a face-up ejection via a branch pawl (not shown) provided in the vicinity of the pair of transport rollers 34 . In the straight ejection, the recording sheet P is further transported and is then ejected by the pair of straight ejection rollers 360 to an external tray unit (not shown) or a finishing unit (not shown). In the face-up ejection, the recording sheet P is further transported upwardly and is then ejected by the pair of face-up ejection rollers 35 into the waist level ejection tray 36 .
The sheet supply mechanism centered with the sheet tray cassette 2 is explained in details below with reference to FIGS. 1 and 2 . The sheet supply mechanism is provided with various components, other than the sheet tray cassette 2 , the pick-up roller 15 , the transport roller 16 , the reverse roller 17 , and the pairs of rollers 24 and 25 , as illustrated in FIG. 1 .
As illustrated in FIG. 2 , the sheet tray cassette 2 includes, an uppermost sheet detector 2 a , a base plate 3 (also see FIG. 1 ) and an elevation member 5 . The uppermost sheet detector 2 a is mounted inside the sheet tray cassette 2 at a predetermined detection height and is configured to generate a signal when detecting an uppermost recording sheet P which reaches the predetermined detection height while being upwardly elevated. The base plate 3 includes two vertical tabs 4 having holes 4 a (see also FIG. 1 ). The elevation member 5 includes a rotary shaft 6 (see also FIG. 1 ), an eccentric rotary plate 7 (see also FIG. 1 ), and two pins 8 .
As a number of the recording sheets P are fed out from the sheet tray cassette 2 , the number of the recording sheets P placed on the base plate 3 is reduced. Consequently, the eccentric rotary plate 7 is driven to have a steeper angle relative to a horizontal plane so as to lift the base plate 3 to maintain the uppermost recording sheet P on the base plate 3 at the predetermined level, that is, the predetermined detection height of the uppermost sheet detector 2 a.
In the transportation of the recording sheet P from the sheet tray cassette 2 , the pick-up roller 15 is driven to rotate. By rotation of the pick-up roller 15 , the uppermost recording sheet P is separated from other remaining recording sheets P contained in the sheet tray cassette 2 and is transferred to the transport roller 16 and the reverse roller 17 . The transport roller 16 further transports the uppermost recording sheet P, and the reverse roller 17 reversely transports any additional recording sheets P erroneously adhered to and carried together with the uppermost recording sheet P. Such erroneous adhesion of sheets to another sheet is caused due to a static electricity. If this reverse roller 17 is not provided, multiple sheets will be transported at a time, which is referred to as a multiple-sheet-feed error.
The recording sheet P correctly singularly transported by the transport roller 16 towards the pair of registration rollers 26 via the pairs of rollers 24 and 25 . The recording sheet P is stopped by colliding with the pair of registration rollers 26 which are in a stop mode. The pair of registration rollers 26 are controllable to be turned on and off so as to synchronize timing of the recording sheet P with timing of the toner image carried on the photosensitive drum 27 . In addition, stopping the recording sheet P by the pair of registration rollers 26 correct a skew of the recording sheet P.
In the sheet tray cassette 2 , the base plate 3 is mounted at a bottom section and is held for rotation with a base shaft (not shown) which is arranged to pass through the holes 4 a and is supported by walls (not shown) of the sheet tray cassette 2 . The base plate 3 has an upper surface extended in a direction A (see also FIG. 1 ) and in a direction B perpendicular to the direction A, on which a number of the recording sheets P are placed. The base plate 3 is rotatable about the base shaft (not shown) in a direction perpendicular to the directions A and B (i.e., a vertical direction in FIG. 1 ).
The elevation member 5 is mounted under the base plate 3 . The rotary shaft 6 of the elevation member 5 is held in parallel to the base shaft of the base plate 3 by the wall of the sheet tray cassette 2 . The rotary shaft 6 has a predetermined length such that one end thereof is positioned under a middle part of the base plate 3 . The eccentric rotary plate 7 has one end side which is fixedly attached to the one end of the rotary shaft 6 so as to be positioned under the middle part of the base plate 3 , as illustrated in FIG. 2 . The rotary shaft 6 has another end on which the two pins 8 are fixed in a manner such that the pins 8 are radially projected, as illustrated in FIG. 2 .
When the rotary shaft 6 is rotated about a central axis thereof, the eccentric rotary plate 7 is also rotated about the central axis of the rotary shaft 6 such that a free end side of the eccentric rotary plate 7 is either lifted or lowered. When the rotary shaft 6 is rotated in one way (e.g., an anticlockwise), the eccentric rotary plate 7 is rotated and the free end side of the eccentric rotary plate 7 is lifted so as to push upwards the base plate 3 . Thereby, the base plate 3 is rotated about the base shaft such that a free end side of the base plate 3 is lifted.
The elevation member 5 is driven by the elevation motor unit 10 . As illustrated in FIG. 2 , the elevation motor unit 10 includes an elevation motor 11 , a coupling 12 , a spring 13 , and a tray controller 14 . The tray controller 14 may also be referred to as an elevation controller. The elevation motor 11 has a motor shaft extended in the direction B, to which the spring 13 and the coupling 12 are connected such that the coupling 12 is slidable by a predetermined stroke along the motor shaft and is constantly pushed outward by the spring 13 . There is a stopper (not shown) which stops a further outward movement of the coupling 12 . The coupling 12 has a cylindrical wall having a hollow and evenly spaced slits 12 a in the wall, as illustrated in FIG. 2 . The tray controller 14 includes electrical components to control the elevation motor 11 by communicating with the uppermost sheet detector and a main electrical unit (not shown) of the image forming apparatus 1 for controlling an entire operations of the image forming apparatus.
When the sheet tray cassette 2 is loaded into the image forming apparatus 1 , the rotary shaft 6 of the elevation member 5 is inserted into the hollow of the coupling 12 . The pins 8 of the rotary shaft 6 which serve as a coupling at a side of the sheet tray cassette 2 are to be inserted into the slits 12 a. When the pins 8 are inserted into the slits 12 a, the coupling is engaged and the power transmission from the elevation motor 11 to the rotary shaft 6 is made possible via the coupling. However, When the pins 8 are not inserted and collide with edges of the cylindrical wall between the slits 12 a, as the sheet tray cassette 2 is further inserted, the pins 8 pushes the coupling 12 against the force of the spring 13 to a predetermined position. Then, a relative position of the pins 8 and the coupling 12 is changed to a position where the pins 8 can enter the slits 12 a. Thus, the coupling 12 is blown off outwardly by the force of the spring 13 and the pins 8 are inserted into the slits 12 a. As a result, the coupling is engaged and the power transmission from the elevation motor 11 to the rotary shaft 6 is made possible via the coupling.
Under the condition that the coupling is thus engaged, the elevation member 5 is rotated as the elevation motor 11 is driven. An amount of rotation of the elevation member 5 corresponds to an amount of vertical lift of the uppermost recording sheet P on the base plate 3 which is detected by the uppermost sheet detector. Depending upon a number of recording sheets P on the base plate, the amount of vertical lift of the uppermost recording sheet P corresponds to the amount of rotation of the elevation member 5 in a range of from approximately 5 degrees to approximately 70 degrees. When the sheet tray cassette 2 is pulled out along a pair of guide rails (not shown) in the direction B, the pins 8 of the rotary shaft 6 is disengaged from the slits 12 a of the coupling 12 . As a result, the base plate 3 drops down due to a self-weight and a weight of the recording sheets P, if any, remaining on the base plate 3 .
As described above, the base plate 3 is lowered when the sheet tray cassette 2 is pulled out. More specifically, the base plate 3 is stopped to be lowered when it collide with a bottom of the sheet tray cassette 2 . The two pins 8 of the rotary shaft 6 are previously arranged to be approximately horizontal at this time, which position is referred to as a pin's home position.
On the other hand, the coupling 12 of the elevation motor unit 10 is set to a home position when the sheet tray cassette 2 is pulled out and the coupling 12 is disengaged from the pins 8 of the rotary shaft 6 of the sheet tray cassette 2 . The home position of the coupling 12 is such that one of pairs of two opposite ones of the slits 12 a is horizontal. When the sheet tray cassette 2 is pulled out, the slits 12 a may not be at the home position. Therefore, when the sheet tray cassette 2 is pulled out, the elevation motor 11 is driven to an extent such that the coupling 12 is set to the home position.
With the above arrangements, the pins 8 of the rotary shaft 6 and the coupling 12 of the elevation motor unit 10 are set to the respective home positions when the coupling is disengaged. Therefore, when the sheet tray cassette 2 is reloaded to the image forming apparatus 1 , the coupling is made in an easy and smooth manner.
Whether the slits 12 a are at the home position or not is detected by using a coupling slit detector (not shown), for example. The elevation motor 11 is driven when the coupling is disengaged to adjust the position of the slits 12 a and is stopped when receiving a home position detection signal from the coupling slit detector, thereby setting the slits 12 a at the home position.
The home position of the slits 12 a is not limited to the horizontal arrangement but it may possibly be at any angle as long as the arrangement of the two pins 8 is changed to fit to such an angle.
With the above arrangement, the pins 8 are easily and smoothly inserted into the slits 12 a and therefore an extra force to push the coupling 12 against the spring 13 may no longer be needed. In addition, an associated supporting member such as a rotary catch for holding the pins 8 at the engagement position may be set to a weaker holding force. Therefore, the operator needs a less energy when loading or unloading the sheet tray cassette 2 to or from the image forming apparatus 1 . In this case, since the pins 8 and the slits 12 a may constantly fit to each other, the spring 13 may not necessarily be needed.
This exemplary embodiment indicates a warning that the sheet tray cassette 2 is pulled out and the coupling 12 is currently being rotated to set the slits 12 a to the home position. This indication warns the operator not to load the sheet tray cassette 2 into the image forming apparatus 1 to avoid an unexpected damage to the components associated with the coupling, while the coupling 2 is being out of the home position.
Referring to FIG. 3 , an exemplary procedure of the warning indication described above is explained. In this procedure, the sheet tray cassette 2 initially is set in an operable position in the image forming apparatus 1 , that is, the pins 8 of the rotary shaft 6 is engaged with the slits 12 a of the coupling 12 . Then, in Step S 1 , the tray controller 14 determines as to a status of the sheet tray cassette 2 , whether the sheet tray cassette 2 is pulled out from the image forming apparatus 1 . This determination step by the tray controller 14 continues to check the status of the sheet tray cassette 2 until the sheet tray cassette 2 is disengaged from the image forming apparatus 1 . When the sheet tray cassette 2 is disengaged from the image forming apparatus 1 and the determination result of Step S 1 is YES, the procedure proceeds to Step S 2 and the tray controller 14 generates a signal for indicating a warning that the slits 12 a of the coupling 12 are currently out of the home position, for example. The warning may indicate a message for prohibiting a reload of the sheet tray cassette until the status becomes ready. Then, in Step S 3 , the tray controller 14 drives the elevation motor 11 to rotate the coupling 12 to set the slits 12 a to the home position. Then, in Step S 4 , the tray controller 14 determines as to a status of the slits 12 a, whether the slits 12 a are set to the home position, based on the home position detection signal from the coupling slit detector. As a result of this determination, when the slits 12 a are determined as not set to the home position and the determination result is NO, the tray controller 14 returns to the process of Step S 3 to repeat the driving of the elevation motor 11 . When the slits 12 a are determined as set to the home position and the determination result is YES, the tray controller 14 proceeds to Step S 5 and terminates the indication of warning. Then, the procedure ends.
The above-described exemplary procedure can effectively prevent an erroneous loading of the sheet tray cassette 2 into the image forming apparatus 1 while the coupling 12 is rotated. Thereby, it becomes possible to avoid an unexpected damage which may be caused to the components associated with the coupling between the sheet tray cassette 2 and the elevation motor unit 10 .
Referring to FIG. 4 , another exemplary embodiment is explained. This embodiment uses a remaining sheet detection mechanism for detecting an amount of the recording sheets P remaining on the base plate 3 of the sheet tray cassette 2 . This embodiment can automatically select a shorter course of rotation of the coupling 12 to set the slits 12 a back to the home position in accordance with an remaining amount of the recording sheets P detected by the remaining sheet detecting mechanism.
This remaining sheet detecting mechanism is linked with the rotation of the elevation motor 11 via a gear system (not shown). As illustrated in FIG. 4 , the remaining sheet detecting mechanism includes a gear 42 , a cam plate 43 , a rotation shaft 44 , and two contact plates 46 and 47 . The gear 42 and the cam plate 43 are concentric and are rotated on the rotation shaft 44 in an integrated manner. The cam plate 43 internally includes four hollow portions 45 e and projection portions 45 f which are arranged to be evenly spaced, as illustrated in FIG. 4 . The contact plate 46 contacts the cam plate 43 when the cam plate 43 is rotated and the projection portion 45 f comes to a position in contact with the contact plate 46 , while the contact plate 47 continuously contacts the cam plate 43 . Accordingly, when the projection portion 45 f comes to a position in contact with the contact plate 46 , the contact plate 46 and the contact plate 47 are in a state of contact.
With the above-described structure, the contact plate 46 contacts the projection portions 45 f periodically on and off as the cam plate 43 is rotated. This periodic contact generates a pulse signal. The tray controller 14 counts this pulse signal.
When the elevation motor 11 is driven, the rotation is transmitted to the rotary shaft 6 via the coupling 12 and accordingly the base plate 3 is lifted. Then, the uppermost recording sheet P is detected by the uppermost sheet detector 2 a, and the elevation motor 11 is stopped based on the detection of the uppermost recording sheet P. During this operation, the tray controller 14 counts the pulse signal received from the remaining sheet detecting mechanism via the contact plate 46 , and calculates a remaining amount of the recording sheets P remaining on the base plate 3 based on the counted pulse signal.
A rotation angle of the coupling 12 is in proportion to the number of revolution of the gear 42 . Therefore, it is preferable to prepare and store a data table beforehand in the tray controller 14 , containing relationship between the number of revolution of the cam plate 43 (i.e., the number of pulse signals), a swing angle of the eccentric rotary plate 7 , and the number of recording sheets P placed on the base plate 3 . With the data table, the tray controller 14 can easily calculate the number of recording sheets P remaining on the base plate 3 and the rotation angle of the coupling 12 at a condition that the elevation motor 11 is stopped.
That is, the tray controller 14 determines a smaller angle passage for the slits 12 a to the home position by calculating clockwise and counterclockwise angles of the slits 12 a to the home position in accordance with an remaining amount of the recording sheets P detected by the remaining sheet detecting mechanism. Then, the tray controller 14 drives the elevation motor 11 to rotate the coupling 12 to set the slits 12 a to the home position in a direction of the smaller angle passage. Thus, a time period for the image forming apparatus 1 to be in a not-ready status is minimized.
Referring to FIG. 5 , an exemplary procedure of controlling the elevation motor 11 is explained. In Step S 10 of FIG. 5 , the tray controller 14 determines as to a status of the sheet tray cassette 2 , whether the sheet tray cassette 2 is pulled out from the image forming apparatus 1 . This determination step by the tray controller 14 continues to check the status of the sheet tray cassette 2 until the sheet tray cassette 2 is disengaged from the image forming apparatus 1 . When the sheet tray cassette 2 is disengaged from the image forming apparatus 1 and the determination result of Step S 10 is YES, the procedure proceeds to Step S 11 and the tray controller 14 determines as to whether a current angle of the slits 12 a is greater than 45 degrees relative to the horizontal plane, that is, an angle of the home position. At this time, the tray controller 14 refers the current angle of the slits 12 a to the data table indicating a relationship between the current angle of the slits 12 a and the remaining amount of the recording sheets P.
When the current angle of the slits 12 a is determined as not greater than 45 degrees and the determination result of Step S 11 is NO, the tray controller 14 proceeds to Step S 12 and drives the elevation motor 11 to rotate the coupling 12 in a direction to decrease the current angle to 0 degrees so as to set the slits 12 a to the home position. Then, in Step S 13 , the tray controller 14 determines as to whether the slits 12 a are in the home position by using the coupling slit detector (not shown). When the slits 12 a are determined as not in the home position, the tray controller 14 returns the process to Step S 12 to repeat the driving of the elevation motor 11 . When the slits 12 a are determined as in the home position, the tray controller 14 ends the controlling procedure of the elevation motor 11 .
On the other hand, when the current angle of the slits 12 a is determined as greater than 45 degrees and the determination result of Step S 11 is YES, the tray controller 14 proceeds to Step S 15 and drives the elevation motor 11 to rotate the coupling 12 in a direction to increase the current angle to 90 degrees so as to set the slits 12 a to the home position. Then, in Step S 15 , the tray controller 14 determines as to whether the slits 12 a are in the home position by using the coupling slit detector. When the slits 12 a are determined as not in the home position, the tray controller 14 returns the process to Step S 14 to repeat the driving of the elevation motor 11 . When the slits 12 a are determined as in the home position, the tray controller 14 ends the controlling procedure of the elevation motor 11 .
Thus, the image forming apparatus 1 can minimize a time period in a not-ready status when the sheet tray cassette 2 is pulled out.
As described above, the amount of rotation of the elevation member 5 is in a range of from approximately 5 degrees to approximately 70 degrees. Since the coupling 12 has the four slits 12 a evenly spaced with 90 degrees, the slits 12 a can be settled at the home position by every rotation of 90 degrees. Therefore, the above determination step compares the current angle of the slits 12 a with a half angle of 90 degrees, that is, 45 degrees.
There is an alternative. The above-described remaining sheet detection mechanism referring to FIG. 4 for detecting an amount of the recording sheets P remaining on the base plate 3 of the sheet tray cassette 2 outputs a stepwise detection of the remaining recoding sheets. For each step of detection, the tray controller 14 can previously calculates and store in a memory a corresponding range of angle of the slits 12 a. Therefore, it is possible to determine a rotation direction of the elevation motor 11 in accordance with a status whether a half of the corresponding range of angle of the slits 12 a applicable to each detection step of the remaining recording sheet is greater than 45 degrees or not.
Next, another exemplary embodiment is explained. This embodiment prevents a damage to components associated with the coupling 12 even when the sheet tray cassette 2 is slowly pulled out and is then reloaded. In this embodiment, the image forming apparatus 1 is provided with a push switch (not shown) for detecting an insertion of the sheet ray cassette 2 when the sheet tray cassette 2 is loaded into the image forming apparatus 1 and pushes the push switch.
When the sheet tray cassette 2 is completely pulled out at one stroke, timing of releasing the push switch is nearly equal to timing of disengagement of the pins 8 from the slits 12 a of the coupling 2 . However, when the sheet tray cassette 2 is slowly pulled out, there may be a case in which the tray controller 14 recognizes the sheet tray cassette is pulled out based on the status of the push switch while the pins 8 are not disengaged from the slits 12 a of the coupling 2 . In this situation, if the tray controller 14 drives the elevation motor 11 to rotate the coupling 12 to set the slits 12 a to the home position, the elevation member 5 may excessively be lifted to cause the uppermost recording sheet P to collide with the pick-up roller 15 , for example, to a damage.
This exemplary embodiment puts a higher priority to the detection of the uppermost recording sheet P by the uppermost sheet detector 2 a than the signal of indicating a release of the push switch. That is, even when the tray controller 14 recognizes the sheet tray cassette is pulled out based on the status of the push switch, the tray controller 14 stops sending the instruction to the elevation motor 11 to rotate the coupling 12 while the uppermost sheet detector 2 a is properly detecting an existence of the uppermost recording sheet P at the predetermined detection height.
Referring to FIG. 6 , an exemplary procedure of the above-described operation is explained. In Step S 20 of FIG. 6 , the tray controller 14 determines as to a status of the sheet tray cassette 2 , whether the sheet tray cassette 2 is pulled out from the image forming apparatus 1 . This determination step by the tray controller 14 continues to check the status of the sheet tray cassette 2 until the sheet tray cassette 2 is disengaged from the image forming apparatus 1 . When the sheet tray cassette 2 is disengaged from the image forming apparatus 1 and the determination result of Step S 20 is YES, the procedure proceeds to Step S 21 and the tray controller 14 determines as to whether the uppermost recording sheet P is at the predetermined detection height based on the detection by the uppermost sheet detector 2 a. When the uppermost recording sheet P is determined as being at the predetermined detection height and the determination result of Step S 21 is YES, the tray controller 14 returns the process to Step S 20 to repeat the same procedure. That is, the tray controller 14 stops causing the elevation motor 11 to rotate the coupling 12 while the uppermost sheet detector 2 a is detecting the uppermost recording sheet P at the predetermined detection height even when recognizing the sheet tray cassette is pulled out.
When the uppermost recording sheet P is determined as not being at the predetermined detection height and the determination result of Step S 21 is NO, the tray controller 14 proceeds to Step S 22 and indicates a warning that the sheet tray cassette 2 is pulled out and the coupling 12 is currently being rotated to set the slits 12 a to the home position. Then, in Step S 23 , the tray controller 14 causes the elevation motor 11 to rotate the coupling 12 to set the slits 12 a to the home position. After that, in Step S 24 , the tray controller 14 determines as to whether the slits 12 a are set to the home position based on the detection by the coupling slit detector. This determination step is repeated until the slits 12 a are determined as being at the home position. When the slits 12 a are determined as being at the home position, the tray controller 14 proceeds to Step S 25 and terminates the indication of warning. Then, the tray controller 14 ends the procedure.
Thus, this embodiment can prevent a damage to components associated with the coupling 12 in a case where the sheet tray cassette 2 is slightly pulled out and is then reloaded.
Techniques described in this patent specification may be conveniently implemented using a conventional general purpose digital computer programmed, as will be apparent to those skilled in the computer art. Appropriate software coding can readily be prepared by skilled programmers based on the techniques described in this patent specification, as will be apparent to those skilled in the software art. The techniques described in this patent specification may also be implemented by the preparation of application specific integrated circuits or by interconnecting an appropriate network of conventional component circuits, as will be readily apparent to those skilled in the art.
Numerous additional modifications and variations are possible in light of the above techniques. It is therefore to be understood that within the scope of the appended claims, the techniques described in this patent specification may be practiced otherwise than as specifically described herein.
This patent specification is based on Japanese patent application, No. JPAP2005-160521 filed on May 31, 2005 in the Japan Patent Office, the entire contents of which are incorporated by reference herein.
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A sheet elevating apparatus for use in a sheet tray cassette detachably installable to an image forming apparatus includes an elevation driving source, a first coupling, an elevation member, a second coupling, and an elevation controller. The elevation driving source is mounted to the image forming apparatus. The first coupling is connected to the elevation driving source and has a home position. The elevation member elevates a plurality of recording sheets placed on an elevating base plate of the sheet tray cassette. The second coupling is connected to the elevation member and is engaged with the first coupling set at the home position when the sheet tray cassette is installed in the image forming apparatus. The elevation controller drives the elevation driving source to set the first coupling to the home position when the sheet tray cassette is pulled out.
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This is a divisional of copending application Ser. No. 08/201,855, filed on Feb. 25, 1994, and now U.S. Pat. No. 5,613,385.
FIELD OF THE INVENTION
The present invention relates to a vehicle detention device capable of securely effectuating detention of an objective wheel of a vehicle parking illegally and preventing such vehicle from moving back and forth by securely restraining an objective wheel so that the vehicle can be prevented from being moved.
BACKGROUND OF THE INVENTION
For example, the Japanese Laid-Open Unexamined Utility Model Application No. 62-114856 (1987) discloses art related to a vehicle detention device. The vehicle detention device disclosed in this Utility Model Publication comprises a pair of wheel stopper blocks respectively coming into contact with an external circumferential surface of a tire of a wheel, a connecting member connecting the wheel stopper blocks by extending itself along the external circumferential surface of the wheel in order to shield an air-injecting hole of the tire and the juncture of the tire and the wheel, and a clamping member secured to a shielding member to permit the wheel stopper blocks to clamp the wheel by sandwiching it therebetween.
Nevertheless, the vehicle detention device disclosed in the above-cited reference executes detention of the upper part of the wheel merely by means of the connecting member extending itself along the external circumferential surface of the tire. This in turn causes the upper part of the connecting member to easily be removed towards the surface side of the wheel, and yet, permits the vehicle detention device to easily be disengaged from the wheel merely by lifting the wheel with a jack, thus failing to exert function proper to the vehicle detention device.
SUMMARY OF THE INVENTION
Therefore, the object of the invention is to fully solve the above problem by providing a low cost novel vehicle detention device, which features simple structure, which is difficult to remove from an objective wheel without unlocking a key, and yet, may easily be secured to the objective wheel.
To achieve the above object, the novel vehicle detention device according to the invention comprises the following:
(1) a stopper block secured to a guide shaft; another stopper block movable itself by long and short distances along the guide shaft toward the former stopper block; a locking means preventing the former stopper block from being shifted from an initial position in the direction away from an objective tire in which both the former and latter stopper blocks are in contact with the objective tire at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the objective wheel; a pair of lengthy chains secured to the former and latter stopper blocks, which are respectively extended from the inside to the outside of the objective wheel by way of forming an X-shape while both the former and latter stopper blocks remain in contact with the objective tire, such chains provided in order to fasten and restrain the objective wheel; and a cover unit provided with a locking key, which fully conceals the mechanical components for releasing the state of detention effected by the fastened chains.
(2) A stopper block may be secured to one end of a horizontally extended cylindrical body; another stopper block may be secured to an end of a slidable shaft having the other end being extensible and retractable from and into the other end of the cylindrical body; a locking means which prevents the latter stopper block from being shifted in the direction apart from the objective tire while both the former and latter stopper blocks remain in contact with the objective tire at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the wheel; a pair of chains secured to the former and latter stopper blocks, which are respectively extended from the inside to the outside of the objective wheel by way of forming an X-shape while both the former and latter stopper blocks remain in contact with the objective tire, such chains provided in order to fasten and restrain the objective wheel; and a cover unit provided with a locking key, which fully conceals the mechanical components for releasing the state of detention effected by the fastened chains.
According to the structure set forth in the above description (1), a wheel subject to detention is fastened and restrained by a pair of chains while a pair of stopper blocks are brought into contact with an objective tire at both sides of a point where the tire contacts a road surface and against the rotating direction of the wheel. Mechanical components for releasing the state of detention are fully concealed by a key-provided cover unit. Therefore, no one can easily remove the inventive vehicle detention device from the restrained wheel without unlocking the key, thus securely maintaining the objective wheel under the state of detention. Furthermore, the vehicle detention device according to the invention is simply structured to enable an operator to easily secure the whole device to an objective wheel to effectuate detention. Therefore, the invention can provide an improved vehicle detention device at an inexpensive cost.
According to the structure set forth in the above description (2), one of the pair of stopper blocks is secured to an end of a cylindrical body, while the other stopper block is secured to an end of a slidable shaft having the other end being extensible and retractable from and into the other end of the cylindrical body. Owing to this structural arrangement, insofar as an objective wheel is held under the state of detention, neither the cylindrical body nor the slidable shaft externally protrude itself from a pair of stopper blocks. For example, even when an objective wheel of a parked vehicle having front tires turned from the straight ahead direction is restrained, pedestrians can be prevented from stumbling over the cylinder body or slidable shaft externally extended.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall perspective view of the vehicle detention device according to the first embodiment of the invention;
FIG. 2 is a cross-sectional view representing the relationship between a guide cylinder and a locking claw provided inside of a casing;
FIG. 3 is a detailed cross-sectional view of a shaft and a strut of an elevating body;
FIG. 4 is an external perspective view of the vehicle detention device according to the first embodiment of the invention when being secured to an objective wheel;
FIG. 5 is an internal perspective view of the vehicle detention device according to the first embodiment of the invention when being secured to an objective wheel;
FIG. 6 is an external view of the vehicle detention device according to the invention after fully being secured to an objective wheel;
FIG. 7 is a cross-sectional view of cover-fixing mechanical components;
FIG. 8 is an internal perspective view of a cover unit;
FIG. 9 is an overall perspective view of the vehicle detention device according to the second embodiment of the invention;
FIG. 10 is a cross-sectional view representing the relationship between a slidable shaft and a locking claw provided inside of a cylindrical body;
FIG. 11 is a cross-sectional view representing the relationship between the slidable shaft and the cylindrical body;
FIG. 12 is a cross-sectional view representing the relationship between a shaft of an elevating body and a strut;
FIG. 13 is an external perspective view of the vehicle detention device according to the second embodiment of the invention on the way of being secured to an objective wheel;
FIG. 14 is an internal perspective view of the vehicle detention device, according to the second embodiment of the invention, being secured to an objective wheel;
FIG. 15 is an external perspective view of the vehicle detention device according to the second embodiment of the invention after fully being secured to an objective wheel;
FIG. 16 is a cross-sectional view of cover-fixing components;
FIG. 17 is an internal perspective view of a cover unit;
FIG. 18 is an overall perspective view of the vehicle detention device according to the third embodiment of the invention;
FIG. 19 is an overall perspective view of the vehicle detention device according to the fourth embodiment of the invention; and
FIG. 20 is an enlarged view of fundamental components by way of designating relationship between stopper blocks and an objective wheel.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 8 respectively designate the fundamentals of the vehicle detention device according to the first embodiment of the invention, in which the reference numerals 1 and 2 respectively designate a pair of wedge-like stopper blocks which jointly inhibit an objective wheel 3 from rotatively moving itself in the forward and backward directions by way of coming into contact with a tire 3a of the wheel 3 at both sides of a point, where the tire makes contact with the road surface and against the rotating direction of the wheel 3. The stopper block 2 is so arranged that it can shift itself by long and short distances against the other stopper block 1. To effectuate this structural arrangement, the stopper block 1 is secured to an end of a horizontally extended guide shaft 4, whereas the other stopper block 2 is movable itself along longitudinal direction of the guide shaft 4 and subject to be locked as of the state in contact with the tire 3a.
More particularly, the guide shaft 4 has a longitudinal end 4a and a center member 4b each having circular section, whereas other longitudinal member 4c and 4d are respectively of square sectional form. Multistep teeth 5 are formed in the longitudinal direction of the guide shaft 4 at equal pitches on the top surface of the square-sectional member 4d between the longitudinal end 4a and the center member 4b. A casing 6 integrated with the stopper block 2 envelops part of the square-sectional member 4d. The casing 6 accommodates a locking claw 7 engageable with the multistep teeth 5. The locking claw 7 climbs over the multistep teeth 5 when the stopper block 2 shifts itself in the direction closer to the stopper block 1 to come into engagement with the multistep teeth 5 when the other stopper block 2 shifts in the direction apart from the stopper block 1. The casing 6 also accommodates an unlocking preventive member 8 which prevents the locking claw 7 from being disengaged from the multistep 5 by act of inserting a thin measure or the like via clearance between the square-sectional member 4d and the casing 6.
In order to shift the stopper block 2 towards the longitudinal end 4a of the circular-sectional portion of the guide shaft 4, initially, while the stopper blocks 1 and 2 are apart from the objective wheel 3, the casing 6 is once shifted to the circular-sectional center member 4b in conjunction with the stopper block 2. Next, the casing 6 is rotated by 90 degrees around the guide shaft 4 in conjunction with the stopper block 2 before positioning the locking claw 7 onto part of surface of the guide shaft 4 devoid of the multistep teeth 5. Then, the casing 6 is shifted towards the circular-sectional longitudinal end 4a in conjunction with the stopper block 2. By effect of integrally turning the casing 6 together with the stopper block 2 shifted to the circular-sectional longitudinal end 4a around the guide shaft 4 and by effect of positioning the locking claw 7 onto the surface provided with the multistep teeth 5, the stopper block 2 can be moved in the direction to sandwich the wheel 3, in other words, the stopper block 2 can be moved towards the other stopper block 1.
The stopper blocks 1 and 2 are respectively provided with a plate body 1a and a plate body 2a respectively coming into contact with the external lateral surface of the tire 3a. The guide shaft 4 and the casing 6 enveloping part of the square-sectional member 4d of the guide shaft 4 are respectively secured to the external surfaces of the plate bodies 1a and 2a.
A cylindrical strut 9 is provided outside of the square-sectional member 4c between the longitudinal end of the guide shaft 4 and the circular-sectional center member 4b. A rectangular cylindrical member 10 set to bottom position is coupled with the cylindrical strut 9 by way of being movable in the longitudinal direction of the guide shaft 4. A vertical shaft 12 is vertically inserted in the cylindrical strut 9 below an elevating body portion 11 forming a T-shape in the front view. Multistep teeth 13 are formed on external surface of the downwardly extended vertical shaft 12 along longitudinal direction at equal pitches. A locking claw 15 provided inside of a casing 14 secured to the upper end of the cylindrical strut 9 comes into engagement with the multistep teeth 13 in order that the elevating body 11 can be positioned at an optional height position. More particularly, a tip portion of the locking claw 15 is supported at upper portion inside of the casing 14 via a horizontal pin 16, whereas a bottom claw 15a is biased in the direction of engagement with the multistep teeth 13 by means of a spring 17. A lever 18 externally projects from the casing 14, where the lever 18 is integrated with the locking claw 15. The claw 15a set to the bottom of the locking claw 15 is disengaged from the multistep teeth 13 by pulling the lever 18 towards operator side in resistance against biasing force of the spring 17. Since the claw 15a at the bottom of the locking claw 15 is fixed in engagement with the multistep teeth 13, a fastening member 19 is provided in order to cause tip of the fastening member 19 inserted in the casing 14 to press the bottom edge of the locking claw 15 in the direction engageable with the multistep teeth 13. An aperture 20 is formed in the vertical direction of the cylindrical strut 9. An engaging shaft 21 is inserted in the bottom end of the shaft 12. An engaging groove 22 of the engaging shaft 21 projects from the aperture 20 to enable a key-provided rotary hook of a cover unit to come into engagement with the engaging groove 22 as will be described later on. A pair of wires 23 and 24 are respectively secured to the interior of the stopper blocks 1 and 2 by way of having one ends respectively being connected to the interior of the stopper blocks 1 and 2. The other ends of the wires 23 and 24 are respectively connected to one ends of a pair of chains 25 and 26. The wires 23 and 24 respectively have specific length enough to externally and internally sandwich the bottom end of the tire 3a of the wheel 3 between the plate bodies 1a and 2a while the tire 3a is sandwiched at both sides of a point where the tire contact the ground surface and against the rotating direction of the wheel 3 by means of the stopper blocks 1 and 2. Chains 25 and 26 connected to the other ends of the wires 23 and 24 are respectively extended from the tip end to the external side of the tire 3a, whereas the other ends of the chains 25 and 26 are respectively caught by a pair of hooks 27 and 28 provided on the top ends of the elevating body portion 11 which forms the T-shape in the front view. More particularly, the top domain of the elevating body 11 consists of an L-shaped sectional horizontally extended plate 29 being orthogonal to the shaft 12 and another L-shaped horizontally extended plate 30 having a plate member 30a which is secured to the plate 29 across a clearance, where the plate member 30a faces in a vertical direction of an external surface of a plate member 29a which faces in a vertical direction of the plate 29. A pair of hooks 27 and 28 are provided on external surface at both ends of the plate member 29a facing in a vertical direction of the plate 29. A pair of hooks 31 and 32 are secured to the bottom surface of a plate member 29b facing horizontal in a direction of the plate 29. Surplus portions of the other ends of the chains 25 and 26 are respectively hung on the hooks 31 and 32.
The reference numeral 33 shown in FIGS. 1, 6 and 8 designates a cover unit for concealing the above-stated mechanism ranging from the bottom side of the cylindrical strut 9 to the top end of the elevating body 11. A folded member 33a provided inside of the top domain of the cover unit 33 comes into engagement with a clearance between the plate member 29a and the plate member 30a from the top side. A rotary hook 34 engageable with the engaging groove 22 of the engaging shaft 21 is provided inside of the cover unit 3. The rotary hook 34 is operated by a locking key inserted from the exterior of the cover unit 33. The reference numeral 35 designates a handle set to the top surface of the cover unit 33. The reference numeral 36 designates a stand unit for erecting the cover unit 33 before being secured to the fundamental components of the vehicle detention device.
Next, a practical method of effectuating detention of an objective wheel of a vehicle using the inventive vehicle detention device complete with the above-stated mechanical structure is described below.
Initially, a pair of wedge-like stopper blocks 1 and 2 integrated with a guide shaft 4 are respectively brought to positions close to an objective wheel 3. Next, the stopper block 2 is shifted along the guide shaft 4 in the direction closer to the stopper block 1. Next, the stopper blocks 1 and 2 are brought into contact with an objective tire 3a at both sides of a point where the tire contacts a road surface and against the rotating direction of the wheel 3. When stopper blocks 1 and 2 are so placed, a cylindrical strut 9 is positioned at the center point between the stopper blocks 1 and 2, in other words, at the center of the forward-backward direction of the wheel 3. Next, using a pair of wires 23 and 24, the bottom edge of the tire 3a is externally and internally sandwiched between a plate la and a plate 2a of the stopper blocks 1 and 2, and then, a pair of chains 25 and 26 connected to the other ends of the wires 23 and 24 are extended over the exterior of the wheel 3 by way of crossing the chains 25 and 26 via X-shape at the tip end of the tire 3a, whereas the other ends of the chains 25 and 26 are respectively hung on a pair of hooks 27 and 28 set to the tip ends of an elevating body 11. While the above operation is underway, fastening force of a fastening member 19 is slackened to position the elevating body 11 as high as possible against the strut 9 so that the other ends of the chains 25 and 26 can easily be hung on the hooks 27 and 28. Next, the elevating body 11 is lowered in order that the wheel 3 can be fastened so closely with the wires 23 and 24 in association with the chains 25 and 26. As a result of fastening by the fastening member 19, a claw member 15a at the bottom end of locking claw 15 is closely engaged with multistep teeth 13 of a shaft 12. Next, surplus portions of the chains 25 and 26 are respectively hung on a pair of hooks 31 and 32. After the ends of chains 25 and 26 are hung, mechanical components ranging from the bottom portion of the strut 9 to the tip of the elevating body 11 are fully concealed by externally securing a cover unit 33 onto them. Finally, by externally operating a locking key provided for the cover unit 33, a rotary hook 34 is engaged with an engaging groove 22 of an engaging shaft 21.
As shown in FIG. 6, it is also permissible for an operator to provide a pair of shielding sheets 36 and 37 made from vinyl or the like (designated by double-dotted chain lines) on the tip end of the elevating body 11 in order to prevent the tire 3a and the wheel 3b from incurring unwanted damage. Furthermore, in order to more securely effect detention of the objective wheel 3, it is optionally possible for an operator to bond the crossing members of the chains 25 and 26 at the tip of the tires 3a with a locking key.
The state of detention effected by the inventive novel vehicle detention device can be released by reversing the steps for restraining the wheel 3 thus far described.
Therefore, according to the first embodiment of the invention, using a pair of chains 25 and 26, an objective wheel 3 is fastened and restrained while a pair of stopper blocks 1 and 2 are brought into contact with the tire 3a at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the wheel 3, and yet, fundamental components for releasing the state of detention are fully concealed by a key-provided cover unit 33. In consequence, no one can readily remove the inventive vehicle detention device from the wheel 3 without operating a proper key, and therefore, the objective vehicle can securely be maintained under detention. Furthermore, the vehicle detention device according to the first embodiment of the invention is characterized by a simple structure permitting an operator to easily secure the device onto an objective wheel 3 to effect detention of a vehicle, while providing a vehicle detention device at a low cost.
Next, referring now to FIG. 9 through 17, the novel vehicle detention device according to the second embodiment of the invention is described below. The reference numerals 41 and 42 respectively designate a pair of wedge-like stopper blocks, which respectively come into engagement with a tire 43a of an objective wheel 43 at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the wheel 43 in order to inhibit the wheel 43 from rotating in the forward and backward directions. The stopper block 42 can be shifted apart from the other stopper block 41 by long and short distances. To effectuate this structural arrangement, the stopper block 41 is secured to an end of a horizontally extended cylindrical body 44, whereas the stopper block 42 is secured to an end of a slidable shaft 45 having the other end being capable of freely entering into and moving out of the other end of the cylindrical body 44.
More particularly, except for the circular-sectional end on the part of the stopper block 42, the slidable shaft 45 is of square-sectional form. Multistep teeth 46 are formed on the top surface of a square-sectional member 45a in the longitudinal direction at equal pitches. A locking claw 47 is provided inside of the other end of the cylindrical body 44. The locking claw 47 climbs over the multistep teeth 46 when the stopper block 42 shifts itself in the direction closer to the stopper block 41. The locking claw 42 comes into engagement with the multistep teeth 46 when the stopper block 42 shifts itself in the direction apart from the stopper block 41. An unlocking preventive member 48 is provided inside of the other end of the cylindrical body 44. The unlocking preventive member 48 prevents the locking claw 47 from being disengaged from the multistep teeth 46 by act of tampering, for example, inserting a thin measure or the like via clearance between the square-sectional member 45a and the cylindrical body 44.
In order to shift the stopper block 42 in the direction apart from the other stopper block 41, initially, while the stopper blocks 41 and 42 are apart from the objective wheel 43, the slidable shaft 45 is shifted in conjunction with the stopper block 42 until the slidable shaft 45 is fully inserted in the cylindrical body 44. Then, in conjunction with the stopper block 42, the slidable shaft 45 is turned by 90 degrees inside of the cylindrical body 44 before positioning the multistep teeth 46 right on the surface devoid of the locking claw 47. While turned by 90 degrees, the slidable shaft 45 is shifted in the direction to draw the shaft 45 out of the cylindrical body 44 together with the stopper block 42. Subsequent to the positioning of the multistep teeth 46 right on the surface provided with the locking claw 47 by inversely turning the slidable shaft 45 and the stopper block 42 by 90 degrees, the stopper block 42 can be shifted in the direction to sandwich the wheel 43, in other words, the stopper block 42 can be shifted towards the other stopper block 41.
The stopper blocks 41 and 42 are respectively provided with a plate member 41a and a plate member 42a which respectively come into contact with external surface of the tire 43a. External surfaces of the plate members 41a and 42a are respectively secured to an end of the cylindrical body 44 and the other end of the slidable shaft 45.
A cylindrical strut 49 is erected inside of the cylindrical body 44 at a position slightly close to an end, apart from the center of the longitudinal direction of the cylindrical body 44. The cylindrical strut 49 is reinforced by means of a reinforcing member 50 having !-shaped horizontal section. An elevating body 51 having a vertical shaft member 42, the combination having a T-shape in the front view is inserted in the cylindrical strut 49 from the top side thereof. Multistep teeth 53 are formed on external surface of the vertical shaft member 52 in the longitudinal direction at equal pitches. A locking claw 55 accommodated in a casing 54 secured to upper portion of the cylindrical strut 49 is engaged with the multistep teeth 53 so that the elevating body 51 can be positioned at an optional height position inside of the casing 54 by means of a horizontal pin 56, whereas a claw member 55a at the bottom end comes into engagement with the multistep teeth 53, where the claw member 55a is energized in the direction engageable with the multistep teeth 53 by means of a spring 57. A lever 58 is integrally provided with the locking claw 53 by way of projecting itself from the casing 54. By effect of pulling the lever 58 towards an operator side in resistance against the biasing force of the spring 57, the claw member 55a at the bottom end of the locking claw 55 can be disengaged from the multistep teeth 53. In order to permit the claw member 55a at the bottom end of the locking claw 55 to be fixed in place while being engaged with the multistep teeth 53, a fastening member 59 presses the bottom end of the locking claw 55 in the direction engageable with the multistep teeth 53 by means of the tip end thereof inserted in the casing 54. When the fastening member 59 is turned to the right, the fastening condition is entered. An aperture 60 is formed in the cylindrical strut 49 in the vertical direction. A tip end of an engaging shaft 61 is inserted in the bottom end of a shaft member 62. An engaging groove 62 of the engaging shaft 61 is provided by way of projecting from the aperture 60. A key-provided rotary hook, (to be described hereinafter) is engageable with the groove 62.
A pair of wires 63 and 64 are respectively secured to the interior of the stopper blocks 41 and 42 by way of having one ends respectively being connected to the interior thereof. The other ends of the wires 63 and 64 are respectively connected to one ends of a pair of chains 65 and 66. The wires 63 and 64 respectively have specific length enough to externally and internally sandwich the bottom end of the tire 43a of the wheel 43 between the plate members 41a and 42a while the tire 43a is sandwiched at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the wheel 43 by means of the stopper blocks 41 and 42. The chains 65 and 66 respectively being connected to the other ends of the wires 63 and 64 are extended from the tip end to the exterior of the tire 43a, whereas the other ends of the chains 65 and 66 are respectively caught by a pair of hooks 67 and 68 provided on the top end of the elevating body 51 having T-shape in the front view. More particularly, the top end of the elevating body 51 consists of an L-shaped sectional horizontally extended plate 69 being orthogonal to the shaft 52 and another L-shaped sectional horizontally extended plate 70 having a plate member 70a being secured to the plate 69 across clearance, where the plate member 70a faces the vertical direction of the external surface of the plate member 69. A pair of hooks 67 and 68 are provided on external surfaces at both ends of the plate member 69 facing the vertical direction of the plate member 69. A pair of hooks 71 and 72 are secured to the bottom surface of a plate member 69a facing the vertical direction of the plate 69. Surplus portions of the other ends of the chains 65 and 66 are respectively hung on the hooks 71 and 72.
The reference numeral 73 shown in FIGS. 9, 15, and 17 designates a cover unit for fully concealing the above-stated fundamental components ranging from the bottom side of the cylindrical strut 49 to the top ed of the elevating body 51. A folded member 73a provided inside of the tip end of the cover unit 73 comes into engagement with a clearance between the plate member 69a and the other plate member 70a from the top side. A pair of grooves 74 and 75 are formed at the upper inside edges on both sides of the cover unit 73, where the grooves 74 and 75 are respectively engaged with the hooks 67 and 68 to effect positioning of the cover unit 73 on the way of securing the cover unit 73 onto the wheel detention mechanism. A rotary hook 76 engageable with the engaging groove 62 of the engaging shaft 61 is provided inside of the bottom end of the cover unit 73 at the center position of the lengthwise direction thereof. The rotary hook 76 is operated by means of a locking key inserted from the exterior of the cover unit 73. The reference numeral 77 designates a pair of plate members provided on the internal surface of the cover unit 73 at the center position of the widthwise direction thereof in order to sandwich the cylindrical strut 49 from both sides while the cover unit 73 is secured to the elevating body 51 and the strut 49. While the fastening member 59 is out of the fastening operation, one of the plate members 77 remains in contact with the fastening member 59 to inhibit fixation of the cover unit 73. The cover unit 73 can properly be secured to the elevating body 51 and the cylindrical strut 49 while the fastening member 59 is turned to the right to effectuate a fastening operation. The reference numeral 78 designates a carrying handle secured to the top surface of the cover unit 73. The reference numeral 79 designates a stand unit to erect the cover unit 73 before securing the cover unit 73 to the elevating body 51 and the cylindrical strut 49.
Next, a practical method of effectuating detention of an objective vehicle by means of the inventive vehicle detention device according to the second embodiment of the invention being characterized by the above structure is described below. Initially, the vehicle detention device is brought to a position very close to the objective wheel 43, and then, in the course of inserting the slidable shaft 45 into the cylindrical body 44, the stopper block 42 is shifted in the direction close to the other stopper block 41. Next, the stopper blocks 41 and 42 are respectively brought into contact with the tire 43a at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the wheel 43. When stopper blocks 1 and 2 are in place, position for securing the strut 49 onto the cylindrical body 44 is established in order that the strut 49 can be set to the center position between the stopper blocks 41 and 42, in other words, substantially at the center of the forward-backward direction of the wheel 43. The bottom end of the tire 43a is then internally and externally sandwiched by the stopper blocks 41 and 42 by means of the wires 63 and 64. The chains 65 and 66 connected to the other ends of the wires 63 and 64 are then respectively extended over the exterior of the wheel 43 by way of crossing the chains 65 and 66 via X-shape at the top end of the tire 43a. Next, the other ends of the chains 65 and 66 are respectively hung on the hooks 67 and 68 provided on the top side of the elevating body 51. At the same time, the elevating body 51 is positioned as high as possible against the strut 49 while fastening member 59 remains loose in order that the other ends of the chains 65 and 66 can easily be hung on the hooks 67 and 68. Next, the elevating body 51 is lowered in order that the wheel 43 can be fastened very closely by means of the wires 63 and 64 in collaboration with the chains 65 and 66. Next, the fastening member 59 is operated to exert a fastening effect to cause the claw member 55a to come into close engagement with the multistep teeth 53 formed on the shaft member 52. Next, surplus portions of the other ends of the chains 65 and 66 are respectively hung on the hooks 71 and 72, and then, mechanical components ranging from the bottom portion of the strut 49 to the top portion of the elevating body 51 are fully concealed by securing the cover unit 73 upon them. Finally, the rotary hook 76 is engaged with the engaging groove 62 of the engaging shaft 61 by way of operating a key from the exterior of the cover unit 73.
As shown in FIG. 15, it is permissible for operator to provide a pair of shielding sheets made from vinyl or the like (designated by double-dotted chain lines) on the top side of the elevating body 51 so that the tire 43a and the wheel 43b can be prevented from incurring unwanted damage. Furthermore, in order to more securely effectuate detention of the wheel 43, crossing members of the chains 65 and 66 at the tip end of the tire 43a may be bonded by means of a locking key. Furthermore, as shown in FIG. 9, a pair of externally projecting plates 82 and 83 may be provided on the bottom sides of the stopper blocks 41 and 42. By virtue of the provision of these plates 82 and 83 on both sides of the stopper blocks 41 and 42, even when a malfeasant attempts to drive the restrained vehicle by starting up the engine thereof while the wheel 43 is still held under detention, a road surface can be prevented from incurring unwanted damage otherwise caused by the bite of the stopper blocks 41 and 42.
The state of detention of the wheel effected by the vehicle detention device can be release by reversing the steps for restraining the wheel 43.
According to the second embodiment of the invention, the objective wheel 43 is fastened and restrained by the chains 65 and 66 while a pair of stopper blocks 41 and 42 are brought into contact with the tire 43a at both sides of a point where the tire makes contact with a road surface and against the rotating direction of the wheel 43, and yet, since fundamental components for freeing the state of detention are fully concealed by the cover unit 73 furnished with a key, no one can readily remove the invented vehicle detention device from the restrained wheel 43 without operating a proper key, thus making it possible for the device to securely retain the objective vehicle under detention. In addition, the vehicle detention device according to the second embodiment of the invention features simple structure to enable operator to readily secure the device onto the objective wheel 43 to effectuate detention of a vehicle, and yet, the invention provides the novel vehicle detention device at a low cost. The stopper block 41 is secured to an end of the cylindrical body 44, whereas the other stopper block 42 is secured to an end of the slidable shaft 45 having the other end being capable of freely entering into and moving out of the other end of the cylindrical body 44. Owing to this structural arrangement, while the objective vehicle is still held under detention, neither the cylindrical body 44 nor the slidable shaft 45 protrudes from the stopper blocks 41 and 42. For example, when a parked vehicle is restrained where the objective tire 43a is tilted against the running direction, pedestrians can be prevented from stumbling over the cylindrical body 44 or the slidable shaft 45 which would otherwise protrude.
Next, referring to FIG. 18, the novel vehicle detention device according to the third embodiment of the invention is described below. In contrast with the second embodiment in which the stopper blocks 41 and 42 are respectively secured to the cylindrical body 44 and the slidable shaft 45, according to the third embodiment, the stopper block 41 is secured to the square-cylindrical body 44 via a hinge 84 so that the stopper block 41 can freely swing itself in the periphery of a vertical shaft. Except for this structural difference, other structural arrangements are identical to those of the second embodiment.
According to the third embodiment, in order to release the state of detention effected by the vehicle detention device of the invention, initially, the wheel 43 is released from the state of detention effected by the wires 63 and 64 in association with the chains 65 and 66. Next, the stopper block 41 is externally rotated in the periphery of a vertical shaft to facilitate removal of the vehicle detention device from the wheel 43. Even when releasing the tire 43a tightly bound by the stopper blocks 41 and 42 from the state of detention, by effect of turning the stopper block 41, the vehicle detention device can readily be disengaged from the wheel 43.
Next, referring to FIGS. 19 and 20, the vehicle detention device according to the fourth embodiment of the invention is described below. The fourth embodiment provides a pair of externally extended tapered members 84 and 85 respectively being integrated with the stopper blocks 41 and 42 made available for the second embodiment. In order that clearance can be formed between the tip ends of the externally extended tapered members 84 and 85 and road surface 86 while the vehicle detention device is secured to the wheel 43, a pair of surfaces 87 and 88 inclining themselves upward are provided on the bottom surfaces of the stopper block 41, the externally extended taped member 84, the other stopper block 42, and the other externally extended tapered member 85. Except for the provision of the externally extended tapered members 84 and 85 and the inclined surfaces 87 and 88, other mechanical arrangements are identical to those of the second embodiment.
The vehicle detention device according to the invention characterized by the above structural arrangements is secured to a front wheel 43 of a vehicle driven by geared rear wheels for example. When the engine of a vehicle held under detention is ignited, load from the front wheel 43 acts upon the stopper block 41 or the other stopper block 42 in the direction of the movement of the vehicle. More particularly, by effect of the shift of the center of gravity of the front wheel 43 to the stopper block 41 or the other stopper block 42 being in the direction of the movement of the vehicle, load acts upon the stopper block 41 or the other stopper block 42 being in the direction of the movement of the vehicle. As a result, the vehicle detention device inclines itself while the inclined surface 87 or 88 remains in contact with road surface 86. FIG. 20 illustrates the state in which the stopper block 42 receives a load from the front wheel 43. A load causes the vehicle detention device to incline itself to generate close contact between the stopper block 42 and the externally extended tapered member 85 integrated therewith and road surface 86 by fully eliminating clearance therebetween. With clearance eliminated, the front wheel 43 and the vehicle detention device secured to the front wheel 43 slidably move themselves on road surface 86. Therefore, even if the vehicle is driven, the vehicle detention device does not rotate preventing the driven vehicle from incurring unwanted damage.
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The vehicle detention device disclosed includes a pair of stopper blocks, a locking means, a pair of chains and a cover unit. One stopper block is fixed to a guide shaft and the other stopper block can be movably displaced to accommodate the size of the object tire. Locking means prevents movable stopper block from being displaced away from contact with object tire maintaining stopper block contact with object tire on either side of tire at ground contact point thus preventing rotation. A pair of chains is used to fasten object wheel to detention device when stopper blocks are placed in the engaged position. Key operated cover unit conceals access to mechanical components needed to release the detention device from the fastened condition thus preventing unauthorized removal of the device from the restrained vehicle.
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CROSS-REFERENCE(S) TO RELATED APPLICATIONS
The present application claims priority of Korean Patent Application No. 10-2010-0024306, filed on Mar. 18, 2010, which is incorporated herein by reference.
BACKGROUND
1. Technical Field
The present disclosure relates to a nano particle used to coat an electrode of a dye-sensitized solar cell.
2. Description of Related Art
With the recent growing concerns on the global warming, development of technologies utilizing environment-friendly energy has been drawing much of public attentions. Solar cell, being one of the most intriguing energy sources as such, study on this field has been diversified including silicon-based solar cells, thin film solar cells using inorganic materials such as copper indium gallium selenide (Cu(InGa)Se 2 ; CIGS), dye-sensitized solar cells, organic solar cells, and organic-inorganic hybrid solar cells. Of them, the dye-sensitized solar cell, which is inexpensive and being drawn close to commercial application, has been highlighted in the fields of building-integrated photovoltaics (BIPV) and portable electronics.
Unlike other solar cells, the dye-sensitized solar cell absorbs visible light and produces electricity through a photoelectric conversion mechanism. In general, patterning of the titanium dioxide working electrode used in the dye-sensitized solar cell is prepared by a screen printing process. Screen printing is a printing technique in which a screen is placed on a work table and a paste is applied on a substrate as it is being passed through a patterned mesh using a rubber blade called the squeegee. The screen printing process is, however, disadvantageous in that it requires a great amount of expensive paste and it is applicable only to a flat substrate. Especially, the control of pattern intervals is important since the efficiency of the solar cell increases in proportion to the light receiving area. The limitation in the control of linewidth between electrodes has been pointed out as the shortcoming of the screen printing technique.
Recently, there has been proposed to form electrode by inkjet printing. This method has advantages that it reduces material loss and has secured control of narrow linewidths and its process is simple. The inkjet-based patterning process looks promising as a direct printing technique applicable not only to flat-panel displays but also to solar cells and other applications.
The inkjet process is advantageous in that, since a wanted pattern can be directly formed on a substrate using an inkjet head having small nozzles, the number of processes and material consumption decrease as compared to the screen printing technique and a desired pattern can be created using a simple computer software. However, because a highly viscous paste cannot be used in the inkjet method, printing has to be performed several times to accomplish an electrode coating with a predetermined thickness.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
SUMMARY
The present invention relates to a titanium dioxide nano particle modified by a surface stabilizer, a nano ink comprising the same, and a dye-sensitized solar cell produced using the same.
An object of the present invention is to make ink-jetting in an inkjet printing procedure easy by capping the surface of a titanium dioxide nano particle with a surface stabilizer.
Another object of the present invention is to provide a titanium dioxide nano ink comprising the titanium dioxide nano particle modified by a surface stabilizer, as well as additives such as an interfacial dispersant and a solvent, a substrate patterned using the titanium dioxide nano ink, and a dye-sensitized solar cell produced using the titanium dioxide nano ink.
The present invention provides a titanium dioxide nano particle coated with a surface stabilizer by chemical bonding so as to provide good compatibility with an ink composition, and a method for preparing the same. The surface stabilizer may be represented by any one of Chemical Formulae 1 to 3. The surface stabilizer has an acid functional group and also has a hydrophobic moiety capable of providing stable dispersion in other materials.
In Chemical Formulae 1 to 3, R 1 , R 2 and R 3 independently represent hydrogen, C 1 -C 20 alkyl, C 2 -C 20 alkenyl, C 2 -C 20 alkynyl or C 6 -C 30 aryl.
The present invention also provides a nano ink comprising the titanium dioxide nano particle capped with the surface stabilizer, a dispersant and a solvent.
The present invention further provides a substrate coated with the nano ink by inkjet printing, and a solar cell with an electrode layer printed using the nano ink. The substrate or the electrode is free from the clogging problem because of minimized cohesion and minimized surface tension on the nozzle, conferred by the surface stabilizer capped on the nano particle surface. Unlike the titanium dioxide thin film prepared by screen printing process, pattern cracking during sintering may be minimized because the particles are uniformly distributed, which leads to maximized diffusion and transition of electrons and improved efficiency of a solar cell. Further, it is advantageous in that it is applicable to a curved substrate since the inkjet process can be used.
The titanium dioxide nano particle of the present invention resolves the clogging problem since the capped surface stabilizer minimizes cohesion and minimized surface tension on the nozzle. The nano ink comprising the titanium dioxide nano particle of the present invention may improve efficiency of a solar cell since occurrence of pattern cracking during sintering is minimized and diffusion and transition of electrons produced by a photoelectric conversion are maximized. Further, it is applicable to a curved substrate since the inkjet process can be employed.
BRIEF DESCRIPTION OF THE DRAWING
The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawing, in which:
FIG. 1 shows a image of a nano ink comprising the titanium dioxide prepared in accordance with the present invention printed by ink-jetting.
DETAILED DESCRIPTION
The advantages, features and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which is set forth hereinafter.
The present invention provides a titanium dioxide nano particle coated with a surface stabilizer by chemical bonding so as to provide good compatibility with an ink composition. The surface stabilizer may be represented by any one of Chemical Formulae 1 to 3. The surface stabilizer has an acid functional group and also has a hydrophobic moiety capable of providing stable dispersion in other materials.
In Chemical Formulae 1 to 3, R 1 , R 2 and R 3 independently represent hydrogen, C 1 -C 20 alkyl, C 2 -C 20 alkenyl, C 2 -C 20 alkynyl or C 6 -C 30 aryl.
The titanium dioxide nano particle capped with the surface stabilizer may be obtained by reacting the surface stabilizer with titanium isopropoxide, a precursor used to prepare a titanium dioxide nano particle. The solvent may be an alcohol, glycol, polyol, glycol ether, or the like. More specifically, methanol, ethanol, propanol, isopropanol, butanol, pentanol, haxanol, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), glycerol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol, propylene glycol propyl ether, etc., may be used alone or in combination of two or more thereof. The proportion of the titanium isopropoxide, the surface stabilizer and the solvent may be 5 to 8 vol %, 0.1 to 1 vol % and 91 to 94 vol %. Preferably, thus produced titanium dioxide colloid solution has a titanium dioxide content from 10 to 15 vol %. By evaporating the solvent from the titanium dioxide colloid solution, a titanium dioxide nano particle having a size of about from 3 to 30 nm may be obtained.
The present invention further provides a nano ink comprising the titanium dioxide nano particle capped with the surface stabilizer, a dispersant and a solvent.
The dispersant is compatible with the surface structure of the nano particle and makes the nano particle disperse well in the solvent without precipitating easily. The dispersant may be a non-ionic surfactant. More specifically, it may be a polyethylene oxide-polypropylene oxide block copolymer or a polyethylene oxide-polystyrene block copolymer represented by Chemical Formula 4 or 5.
In Chemical Formulae 4 and 5, n and m independently represent an integer from 1 to 30.
The copolymer represented by Chemical Formula 4 or 5 provides improved lubrication at the interface with the titanium dioxide nano particle and thus is effective in improving dispersibility when it has a polyethylene oxide (CH 2 CH 2 O) content from 30 to 80 wt % based on the total weight of the copolymer.
The solvent for the titanium dioxide nano ink may be an alcohol, glycol, polyol, glycol ether, etc. More specifically, it may be methanol, ethanol, propanol, isopropanol, butanol, pentanol, haxanol, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), glycerol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol, propylene glycol propyl ether, or a mixture thereof.
In the titanium dioxide nano ink of the present invention, the proportion of the titanium dioxide nano particle, the dispersant and the solvent may be about 10 to 70 parts by weight, about 0.1 to 10 parts by weight and about 20 to 82 parts by weight. If the content of the titanium dioxide nano particle is less than 10 parts by weight, the number of inkjet printing has to be increased. Meanwhile, if it exceeds 70 parts by weight, the ink may be inappropriate for inkjet printing because of too high viscosity. If the content of the dispersant is less than 0.1 part by weight, a desired effect may not be attained. Meanwhile, if it exceeds 10 parts by weight, the ink may be inappropriate for inkjet printing because of too high viscosity.
The titanium dioxide nano ink of the present invention may have a viscosity from about 1 to 50 cps at room temperature. If necessary, the ink of the present invention may be heated to about 80° C. or below during application to reduce viscosity. By heating to 80° C. or below, the viscosity may be reduced to about 1 to 20 cps. The nano ink of the present invention may further comprise a viscosity modifier. The viscosity modifier serves to modify the viscosity of the nano ink to be appropriate for printing.
The present invention further provides a solar cell with an electrode layer printed using the titanium dioxide nano ink. After applying the titanium dioxide nano ink on a substrate, the substrate may be sintered to form an electrode pattern. The electrode pattern may be formed by inkjet printing. The inkjet printing method is advantageous in less material loss, easier control of narrow linewidths, a simpler process, or the like. Non-limiting examples of the substrate include a glass substrate, a transparent polymer substrate and a flexible substrate. The sintering may be performed at about 300 to 500° C. for several minutes to several hours. During the sintering process, organic compounds included in the titanium dioxide nano ink such as the dispersant and the solvent are decomposed and destroyed, and the remaining titanium dioxide nano particles form a porous electrode.
EXAMPLES
The examples and experiments will now be described. The following examples are for illustrative purposes only and not intended to limit the scope of the present invention.
Example
Preparation of Titanium Dioxide Nano Particle and Manufacture of Solar Cell Using the Same
Toluenesulfonic acid (1.72 mL) was dissolved in butanol (25 mL). After mixing butanol (150 mL) with Millipore water (5 mL) and adding titanium isopropoxide (12 mL), the resultant mixture was added to the toluenesulfonic acid solution. The mixture was reacted at room temperature for 1 hour and then at 110° C. for 6 hours. The reaction was proceeded further by adding phenylsulfonic acid.
The solvent was evaporated from the resultant titanium dioxide colloid solution to adjust the volume to about 120 mL.
Polyethylene oxide-polypropylene oxide copolymer (40:60, based on weight, 10 g) was added to the solution and then mixed. 1 hour later, the solution was treated with a tip-type sonicator for 10 minutes. FIG. 1 shows an image of thus prepared titanium dioxide nano ink printed by ink-jetting. It can be seen that the titanium dioxide nano particles are dispersed well with an interval of 200 μm.
The prepared nano ink was injected into a printer head and an electrode was applied on a glass substrate. After heating at 300° C. for 1 hour, the substrate was sintered at 500° C. for 3 hours. After adsorbing a dye (N3, Solaronix) on thus prepared electrode for 24 hours at room temperature, it was bonded with a platinum counter electrode substrate (Surlyn, DuPont) at 120° C. After injecting an electrolyte through a previously prepared hole, a dye-sensitized solar cell was completed by blocking the injection hole with Surlyn.
Comparative Example
A dye-sensitized solar cell was prepared according to a commonly employed method. A titanium dioxide paste (Solaronix) for screen printing was coated on a fluorine-doped tin oxide (FTO)-coated glass substrate using a screen printing apparatus. After heating at 300° C. for 1 hour, the substrate was sintered at 500° C. for 3 hours. After adsorbing a dye (N3, Solaronix) on thus prepared electrode for 24 hours at room temperature, it was bonded with a platinum counter electrode substrate (Surlyn, DuPont) at 120° C. After injecting an electrolyte through a previously prepared hole, a dye-sensitized solar cell was completed by blocking the injection hole with Surlyn.
Current density (J sc ), voltage (V oc ), fill factor (FF) and energy conversion efficiency of the dye-sensitized solar cells according to the Example and Comparative Example were evaluated and compared, as summarized in Table 1. It can be seen that the present invention provides improved energy efficiency. Besides, the present invention is advantageous in that it lowers production cost due to the decreased ink consumption, has simplified process and applicability to a curved substrate.
TABLE 1
Energy
Current
Voltage
Fill factor
conversion
Samples
density (J sc )
(V oc )
(FF)
efficiency (%)
Example
4.09
0.623
0.679
1.73
Comparative
3.95
0.622
0.655
1.61
Example
While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.
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Disclosed are a titanium dioxide nano ink having such a strong dispersibility as to be applicable by inkjet printing and having adequate viscosity without requiring printing several times, and a titanium dioxide nano particle modified by a surface stabilizer included therein. Inkjet printing of the titanium dioxide nano ink enables printing of a minute electrode. In addition, efficiency of a solar cell may be maximized since occurrence of pattern cracking is minimized.
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[0001] This application is a continuation of patent application Ser. No. 10/977,190, filed Oct. 28, 2004 and issued as U.S. Pat. No. 8,120,521 on Feb. 21, 2012, which claims priority from prior, co-pending U.S. Provisional Application No. 60/514,965, filed Oct. 28, 2003 by the same inventor, and entitled “Radar Visual Assistance Device”, which applications are both incorporated herein by this reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to radar (“radio detection and ranging”), and more specifically relates to down-converting reflected radio-frequency energy to audio output. One application of the invention is, for example, using radar to assist the visually impaired.
[0004] A method of frequency down-converting a radio frequency (RF) carrier termed ultra-wide-band (‘UWB’) was invented by McEwan et al. at Lawrence Livermore National Laboratories (LLNL) years ago (See U.S. Pat. Nos. 5,345,471, 5,361,070, and 5,661,385). This technique, herein termed “integrated sampling,” is being widely licensed for commercial use of the technique for multiple radar-related purposes. The basis of this integrated sampling technique was originally developed earlier in conjunction with the development of sampling oscilloscope technology. In more modern terms, the technique can be viewed as a form of “digital downconversion” where subsampling is used to alias the original spectrum down to a much lower frequency spectrum. In the case of the LLNL technology, the technique retains much of the older sampling oscilloscope technology in that the sampler is purely analog in nature with no analog-to-digital conversion employed.
[0005] The LLNL integrated sampling technique differs from more conventional methods of radar signal processing in that the RF carrier is directly down-converted to an intermediate frequency (IF) without the conventional use of mixer or local oscillator components. As long as the radar echo is consistent during the integrated sampling time period (millions of pulses and samples per second), the time-domain nature of the original RF carrier is accurately duplicated, for example, at the IF frequency, typically selected to be in the audio frequency range. This means that the “nature” of the radar echo is preserved upon down-conversion. The complete amplitude, phase, and Doppler characteristics of the echoed waveform are preserved and time-scaled, including propagation delay. Thus, by this technique, the speed of light propagation of the RF carrier scales down to approximately speed-of-sound delays when down-converted via integrated sampling.
[0006] 2. Related Art
[0007] U.S. Pat. No. 3,626,416 (Rabow):
[0008] This patent mentions conversion of received RF signals in two receivers to audio for presentation to human ears. The patent mentions only heterodyning conversion; the patent discloses only direction finding for an external radio frequency source, and does not mention radar echoes; and, the patent does not mention using the device for visual assistance. Relative to the present invention, disadvantages of this disclosed system are: echo time differential to each receiver is at the speed of light, and this differential is maintained through-out the system; and no provision for self-generation of the RF signal, that is, radar echo, is made.
[0009] U.S. Pat. No. 3,940,769 (Sherman, et al.):
[0010] This patent mentions conversion of an RF radar echo into binaural audio for the purposes of allowing an operator to listen to the radar echo. The patent discloses a very specific means of processing the two received audio signals in terms of “sum” and “difference” audio channels derived from left side and right side radar receivers. Both channels are presented to each ear with one ear receiving the “sum channel” plus the “difference channel” and the other ear receiving the “sum channel” plus a filtered and inverted “difference channel”. The purpose of the patent is to enhance the angular difference in terms of audio amplitude, and a long derivation of proper filtering parameters is made in it; the patent does not mention using the technique for visual assistance; and, in the patent no specific method of converting the RF signal to audio is made, using the patent phrase “well-known methods of detection, demodulation, or heterodyning.” Relative to the present invention, disadvantages of this disclosed system are: echo time differential to each receiver is at the speed of light, and this differential is maintained through-out the system; and, the signal at each ear is a processed vectoral sum of two audio signals, with the original echo content being perturbed and blended.
[0011] U.S. Pat. No. 4,280,204 (Elchinger):
[0012] This patent mentions use of an ultrasonic device mounted onto a conventional mobility cane for assistance of the blind. The disclosed ultrasonic range finder can be configured for variable range and direction pointing. The patent discloses the ultrasonic echo being measured for range, and a separately created tone is sent to the user to indicate range. Relative to the present invention, disadvantages of this disclosed system are: the original ultrasonic echo is not sent to the user to allow echo content to be used as a part of the information signal; the disclosed device is cumbersome in that the user must configure and reconfigure it to point in a desired direction and to set a desired range; and, in general, ultrasonic echo location suffers from several drawbacks: limited useful range of less than about 20 feet; poor performance in high wind, rain and snow; subject to ultrasonic noise interference; and, narrow coverage zone for any single transducer.
[0013] U.S. Pat. No. 4,761,770 (Kim, et al.):
[0014] This patent mentions presenting a binaural echo signal to the user's ears using two ultrasonic receivers. The signal is “downconverted” from ultrasonic to sub-audio via “bucket-brigade” (BB) circuitry to time-stretch the signal. The original echo is sampled into the BB device at one clock-rate, and then extracted from the BB device using a much slower clock rate. The time-stretch is purposely configured to place the downconverted ultrasonic signal into the sub-audio range so that time delays in echoes are stretched to more discernable delays as a function of distance and human ability to discern delay; and, the sub-audio signal is then modulated with a white-noise signal to create an audible sound for the user. Relative to the present invention, disadvantages of this disclosed system are: the original ultrasonic echo is distorted by the extreme time-stretching to sub-audio and then modulated with white noise. Therefore, the original true echo content is lost; and, the system is based upon ultrasonics and suffers from the general drawbacks of ultrasonics noted above regarding the Elchinger reference.
[0015] U.S. Pat. No. 5,107,467 (Jorgensen, et al.):
[0016] This patent mentions presenting two receivers to provide an echo signal to the user's ears, based upon ultrasonics. The original echo signal is peak detected and sampled via analog-to-digital conversion. It is then digitally delayed and stretched in accordance with range via a non-linear stretching algorithm. A processed signal called an “echo profile” is recreated at audio frequency via digital-to-analog conversion using the variable clock in accordance with the variable delay and time-stretching algorithm. Relative to the present invention, disadvantages of this disclosed system are: the original ultrasonic echo is distorted by peak detector, A/D conversion, and D/A conversion with non-linear time stretching. Therefore, much of original true echo content is lost; and the system is based upon ultrasonics and suffers from the general drawbacks of ultrasonics noted above regarding the Elchinger and Kim, et al. references.
[0017] U.S. Pat. No. 6,671,226 (Finkel, et al.):
[0018] This patent mentions using multiple ultrasonic range finders positioned at various angles on the chest area of the user to try and cover a broad area. The signal sent to the user is manufactured based upon echo-range response in each ultrasonic transceiver. Each transceiver is sequentially activated, and if a target is sensed for that transceiver a tone unique to each transceiver is sent to the user. Relative to the present invention, disadvantages of this disclosed system are: the original ultrasonic echo is not preserved; the system is cumbersome due to the large number of transceivers pointing in different directions, with each transceiver having its own tonal output; and the system is based upon ultrasonics and suffers from the general drawbacks of ultrasonics noted above regarding the Elchinger, Kim, et al., and Jorgensen, et al. references.
SUMMARY OF THE INVENTION
[0019] The echolocater device described herein incorporates the features of integrated sampling radar technology to create a unique device that provides, for example, the visually impaired with an excellent new tool to help navigate the world. Although the integrated sampling technique is discussed herein as a preferred embodiment, other conventional means of downconverting the radar signal spectrum to audio could also readily be employed without deviating from the spirit of this invention.
[0020] The human brain is very capable of “processing” audio frequencies, and there is likely no group of humans that can process sounds better than the visually impaired. Much like a bat using its bio-sonar, the visually impaired will be able to hear subtle differences in audio-replicated radar echoes.
[0021] In one preferred embodiment of the invention, two integrated-sampling type radar receivers are spaced some convenient distance apart. A single transmitter centered between the two receivers transmits pulses of an RF carrier. The complete device may be worn in belt or vest form on a person and is completely portable and low-profile. Audio “IF” output from each receiver is processed and sent to a small speaker worn near each ear. In this manner the radar echoes take on a 3-dimensional quality just as ordinary sound does when played by a stereo sound system. With practice, the user of this invention will be able to discern the range, location and motion of individual objects, and may also be able to distinguish particular echo characteristics of differing objects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 : Functional block diagram of LLNL licensed integrated-sampling based radar.
[0023] FIG. 2 : Schematic diagram of LLNL licensed integrated-sampling based radar.
[0024] FIG. 3 : Functional schematic diagram of one embodiment of the present invention.
[0025] FIG. 4 : Functional form factor for one belt-like garment embodiment of the present invention.
[0026] FIG. 5 : Functional form factor for one vest-like garment embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] One preferred embodiment of the invention incorporates existing technology for frequency down-converting an RF carrier, using integrated sampling. The basic technique is licensed by Lawrence Livermore National Laboratories for commercial development of a wide-variety of radar-related devices. FIG. 1 is a functional block diagram illustrating the key elements of the licensed technology as used in this invention. FIG. 2 shows electrical schematic realizations of the functional blocks as shown in U.S. Pat. Nos. 5,345,471, 5,361,070, and 5,661,385.
[0028] Block 1 represents the fundamental pulse-repetition-frequency (PRF) clock for the radar system. This PRF clock is shown to be a square wave feeding into inverter U 1 -A in FIG. 2 . Functional block 2 is the RF transmit gate for the radar, which is seen to be simply another inverter gate, U 1 -B, in FIG. 2 . Block 3 represents the creation of the RF transmit radar pulse. This pulse is created as an RF burst resulting from the action of circuit components C 2 , R 3 , C 3 , L 1 , Q 1 , L 2 , R 4 and C 4 when gated by the square-wave output of U 1 -B in FIG. 2 . The radar pulse is then fed to the radar transmit antenna 4 , which is appropriately selected for the chosen frequency of operation and bandwidth of the RF burst. If necessary, attenuation may be added (not shown) just prior to the transmit antenna 4 to meet regulatory requirements (i.e., FCC Title 47, Part 15). A resistive “T” or “Pi” configuration may be used, and is well known to those skilled in the art of high frequency electronics, as is the proper selection of antenna type and configuration best suited for the particular RF carrier frequency and pulse width selected for any particular embodiment.
[0029] Functional block 5 creates a sliding delay in the Receiver Gate 6 in order to allow for range resolution of the received radar pulse signals (echoes from objects). Components R 1 , R 2 and C 1 in FIG. 2 create a very simple, but very effective circuit for accomplishing a controllable, precise Receiver Gate 6 delay relative the Transmit Gate 2 . Components R 2 and C 1 are all that is necessary to create a fixed delay of the Receiver Gate U 1 -C relative to the Transmit pulse. Component R 1 allows for the realization of a dynamically controllable delay function created by scaling the contribution of a variable Delay Control Voltage fed into R 1 . Voltage waveforms and component values are typically determined via an empirical process to achieve particular desired results.
[0030] Receiver Gate 6 (U 1 -C) drives the sampling Step Generator 7 which in turn drives the Switched Sampler 8 to accomplish the integrated-sampling down-conversion of the RF pulsed carrier to the desired intermediate frequency (IF). In FIG. 2 the Step Generator 7 consists of components R 5 , C 5 , D 1 and C 9 . The output of the Step Generator 7 is a very narrow negative pulse created by properly driving the step recovery diode D 1 . When the step diode D 1 “snaps” off very quickly, a negative pulse is coupled via C 9 to the Switched Sampler 8 consisting of RT, C 6 , D 3 , R 7 , R 8 and C 7 . The very narrow pulse briefly turns on D 3 and charges C 6 for a portion of the RF echo carrier cycle. This action creates a single “sample” of the RF echo. Optimum timing for the Step Generator driving the Switched Sampler has been found to be about ½ of the RF carrier period. Odd multiples of ½-period have also been found to be effective.
[0031] When D 3 returns to its nominal off state, the charge on C 6 transfers to C 7 via R 7 . A sample is taken once every PRF clock, so the time constant of R 7 and C 7 is chosen to be less than the PRF clock to accomplish charge transfer during each PRF period. The time constant of C 7 and R 8 is selected to be much larger than the PRF clock to maintain the accumulated charge samples between PRF clock cycles, but less than the intermediate frequency to allow the sampler to properly respond to echo changes. Note that the resistors RT are selected to impedance match the receiver antenna 9 .
[0032] Note that it may be desirable to first boost the received RF echo signal level by inserting one or more RF amplifier stages (not shown) between the Receiver Antenna 9 and the Switched Sampler 8 . Many appropriate options are available to achieve this RF amplification and are well known to those skilled in the art of high frequency electronics.
[0033] Components U 2 , R 9 , C 8 and R 10 of FIG. 2 form the IF Buffer and Pre-Amplifier block 10 . This is a simple operational amplifier circuit with gain equal to the ratio of R 9 /R 10 for frequencies where the impedance of C 8 is much greater than R 9 . C 8 is selected properly so that it may be used as a high-frequency filter element reducing amplifier gain as the impedance of C 8 becomes small for frequencies much higher than the IF.
[0034] The realized IF frequency is a function of the sliding receiver gate delay, and to some extent, the RF carrier and the PRF as well. The PRF determines how often samples of the RF carrier are taken, but the primary determinant of the IF is the sliding delay function. The sliding delay determines the rate-of-change of the relative timing when samples are taken of the radar echoes. In a static situation where the radar and any echo-producing objects are not moving, the transmit pulse is the same every PRF clock cycle, and therefore the radar echo is also the same every PRF clock cycle. A sliding delay function “slides” the sampler along the time-static radar-echo-waveform and reconstructs the radar echo on a sample-by-sample basis at an expanded time scale. The IF is therefore essentially defined by how fast the sliding occurs along the echo's time scale.
[0035] A smooth, sliding delay is accomplished by feeding a ramp voltage into R 1 causing a small incremental delay in each subsequent sample initiated by the Receiver Gate 6 . This delay is always relative to the Transmit Gate 2 , which occurs once each PRF clock cycle. Optimal shaping of the ramp is dependent upon the range to be searched and the values of the other delay control components R 1 , R 2 and C 1 .
[0036] If there is relative motion between the radar and echoed objects, then the sliding sample adds to the relative “motion” of the echo waveform, and the resulting IF is shifted accordingly in frequency (Doppler shift). Accurate time-scaled reconstruction of the RF carrier using integrated sampling holds true as long as the radar echo is consistent (coherent) during the integrated sampling time period so that subsequent samples add coherently to the prior samples. In human terms, coherency will almost always occur for ordinary objects and ordinary motion because the radar echo off the object will remain constant in any 10's to 100's of milliseconds time frame, allowing thousands to millions of samples to be taken and added constructively.
[0037] A unique property that arises from this integrated sampling technique is that the RF carrier is accurately reconstructed at the IF frequency, typically selected to be in the audio frequency range. This property is a significant feature of the present invention because the amplitude, phase, propagation delay, and Doppler characteristics of the echoed waveform are preserved and directly time-scaled. It should be noted that any other method of downconverting the RF radar echo to audio can also be used without deviating from the spirit and intent of this invention.
[0038] The scaling of the propagation delay is a particularly significant advantage in the preferred embodiment of the present invention because the speed of light propagation of the RF carrier scales to approximately speed-of-sound propagation timing when down-converted to audio frequencies. For example, it is known that an RF carrier propagates at the speed of light, 3×10 8 meters/second, and sound propagates on the order of 330 meters/second. If the sliding delay is configured such that a time scaling of about 900,000 occurs via the integrated sampling, then the RF propagation scales to exactly the speed of sound where the human ear is already accustomed to hearing small relative delays to discern direction and distance. For a 5.8 GHz carrier, a scaling of 900,000 results in an audio frequency output of 6.4 KHz. In practice the scaling factor may be chosen to be larger to both reduce the audio frequency to a more pleasant tone and to further enhance the delay effect to some degree.
[0039] Integrated sampling down-conversion of the RF carrier when processed carefully in accordance with this invention allows the processing power inherent in the human brain to be used to “hear” subtleties in the down-converted radar echo. The human brain can act as its own sophisticated “signal processor” for the radar echoes. Distance, direction and relative motion should be discernable. With practice, the user may even learn to distinguish echo characteristics of differing objects.
[0040] FIG. 3 illustrates one embodiment of the present invention, a Radar Visual Assistance Device, in a functional block schematic format, and FIG. 4 illustrates a preferred form factor for this Visual Assistance system. All functional blocks in FIG. 3 are common in the field of electronics, and may be applied in accordance with the skill of the practitioner and in accordance with the restrictions described herein. FIG. 3 represents one preferred embodiment, but should not be construed as the simplest embodiment nor the embodiment with maximum possible feature set. The same is true for the preferred form factor illustrated in FIG. 4 .
[0041] The Visual Assistance system is controlled via embedded microprocessor 14 . The microprocessor provides maximum design flexibility and customization potential via software changes rather than hardware changes. In the embodiment shown, the microprocessor shares the radar system clock 1 derived from a simple crystal oscillator 12 and buffered by 13 to drive both sections of circuitry (radar portion and microprocessor). It can be seen in FIG. 1 that for the radar portion of the invention, the PRF clock 1 drives a single pulsed radar transmitter via Transmit Gate 2 as previously described and two identical integrated-sampling radar receivers of the types previously described. Although the LLNL technology discussed above was originally invented in relation to ultra-wide-band (UWB) radar, the present invention may be applied to wideband, narrowband, and even continuous wave (CW) radar devices.
[0042] In the embodiment shown in FIG. 3 , the microprocessor 14 is used to drive a digital-to-analog converter (DAC) 15 to create the sliding delay control voltage. The DAC output is buffered by unity gain op-amp 16 to feed delay control circuitry R 1 , R 2 , and C 1 . Other methods of providing a variable delay control voltage are possible and may be applied by those skilled in the art. This circuitry now drives two identical radar receiver gates 6 which in turn drive two identical integrated-sampling receivers as previously described. Identical electrical gating delay for the two radar receivers is very important in order to accurately preserve the relative 3-dimensional propagation delay for the radar echo.
[0043] Microprocessor 14 also drives DAC 17 , which is buffered by unity gain op-amps 18 to provide two identical control voltages to a simple type of attenuator consisting of MOSFET transistors 19 and resistors 20 . MOSFET transistors 19 are driven in the “ohmic” region (saturation region) to realize a voltage-controlled resistor thus providing a voltage controlled resistor divider attenuation network when used with resistors 20 . Other time-adjustable attenuator configurations are possible and may be applied by those skilled in the art.
[0044] The attenuator portion of the circuit is used to adjust the gain of the received IF signal 11 over time to compensate for the fall off of the radiated energy as the square of distance, or the fall off of the echoed energy in proportion to the inverse of range to the fourth power. The attenuation is typically high at the beginning of the range sweep and low at the end of the range sweep because the echo return energy is expected to be very high at the beginning relative to the energy received at the end of the range sweep occurring from objects further away.
[0045] In the embodiment of FIG. 3 , the output of the attenuators 19 - 20 is buffered by unity gain op-amps 21 , which feed into the Stereo Audio Processing Circuitry 22 . There are a great many options available to the practitioner in this portion of the invention because the art of stereo audio electronics is quite advanced. In one preferred embodiment, 22 will consist of a stereo CODEC device and a digital signal processor device to provide programmable audio filtering, proprietary audio signal enhancement, and perhaps some user-controllable audio features. In a simpler embodiment, 22 might consist of just an audio filter stage with gain and drive sufficient to directly drive the speakers 23 and 23 ′.
[0046] The processed stereo signal from 22 is fed to a pair of speakers, or other sound transducers, 23 . The speakers 23 and 23 ′ may be in the form of stereo headphones, or preferably in the form of small speakers worn on the body near each ear, but not covering the ear, so that the user is afforded maximum normal hearing sensitivity.
[0047] The entire system is battery operated 24, preferably by a high-energy rechargeable battery source to provide several hours of function between recharge cycles.
[0048] User controls 25 such as on/off, volume control, and other possible user selectable features (see Table 1) are fed to the microprocessor 14 in this embodiment. In this manner the microprocessor 14 can assume complete control over all radar and audio processing functions. For example, audio volume selection might be adjusted via either a signal to the DSP in 22 or by adjusting the Attenuators at DAC 17 . On/off function could simply consist of a very low-power sleep mode. More conventional means of controlling these features such as a SPST switch for on/off control and potentiometers for volume might be used according to the practitioner's preferences.
[0049] A complete Radar Visual Assistance system is illustrated in two, but not all, alternative embodiments in FIG. 4 (a waist belt embodiment 100 ) and FIG. 5 (a vest embodiment 200 ) which represent two preferred form factors. The primary control unit 26 and 26 ′ houses the batteries, the user controls, the processing circuitry, and the radar pulse transmitter. The control unit 26 and 26 ′ is centrally located to radiate the transmit pulse symmetrically outward with respect to the user's “head-on” or front-facing perspective.
[0050] The control unit 26 and 26 ′ feeds power and identical radar receiver gate clocks via belt 27 or via internal vest wiring 27 ′ to the left radar receiver 28 and 28 ′ and identical right radar receiver 29 and 29 ′. Radar receivers 28 and 28 ′ and 29 and 29 ′ are nominally spaced some distance apart, the distance being greater than or equal to the nominal spacing of ears on the human head. Since the integrated sampling technique scales the radar pulse propagation time to essentially the speed of sound, the relative delay between each receiver produces a 3-dimensional effect familiar to the human brain.
[0051] The vest-type configuration 200 may be a preferable alternative to the belt embodiment 100 illustrated. In all form factors, it is crucial that the radar gating electrical delay is kept identical to each receiver 28 and 28 ′ and 29 and 29 ′ in order to preserve the proper relative echo propagation delay for each receiver 28 and 28 ′ and 29 and 29 ′ when converted to audio via integrated sampling. Likewise, audio gain must be identical in each IF to speaker path. It may be desirable to factory calibrate the audio gain portion of the circuitry for system response to a nominal “head-on” object.
[0052] Finally, the control unit 26 and 26 ′ feeds the processed, finished audio stereo signal to the speakers 23 and 23 ′ via cable 30 and 30 ′. Cable 30 and 30 ′ and speakers 23 and 23 ′ may be embedded into the vest configuration near the user's shoulders as shown in FIG. 5 , or may be embodied as a headphone system 123 ′ shown as an alternative speaker configuration in FIG. 5 . Other user-friendly alternative configurations may be used as desired.
[0053] The invention has a great many design parameters which are adjustable to create differing effects in the finished audio stereo output. Many of these adjustable parameters might be incorporated as user controls to allow the user to customize the performance to their own liking. User controls could be implemented via the microprocessor 14 and stereo audio processing circuitry 22 to provide some sort of audible feedback for particular selections to assist the visually impaired with making desired selections. Table 1 summarizes many of the parameters which might be adjusted, and briefly describes the effect produced and how they could be embodied. The description should be sufficient for those skilled in the art of electronics to be able to implement these features into various embodiments of the invention.
[0000]
TABLE 1
Adjustable Design Parameters
Parameter
Description
Implementation
Effect to User
Range Sweep
Microprocessor control of
Adjust max range; adjust
Rate
the delay voltage
repetition rate
Audio Tone or
DSP algorithm, audio
Tonal preferences, enhance
Frequency
filtering
or modify tone versus
range relationship
Delay Control
Microprocessor adjusts
Creates tonal shift and/or
Voltage Profile
DAC algorithm
max range adjustment
Attenuation
Microprocessor adjusts
Adjusts relative amplitude
Profile
DAC algorithm
of near versus far objects
[0054] Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims.
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The echolocater device described herein incorporates the features of integrated sampling radar technology to create a unique device that provides, for example, the visually impaired with an excellent new tool to help navigate the world. Much like a bat using its bio-sonar, the visually impaired will be able to hear subtle differences in audio-replicated radar echoes. In one preferred embodiment of the invention, two integrated-sampling type radar receivers are spaced some convenient distance apart. A single transmitter centered between two receivers transmits pulses of an RF carrier. Audio “IF” output from each receiver is processed and sent to a small speaker worn near each ear. With practice, the user of this invention will be able to discern the range, location and motion of individual objects, and may also be able to distinguish particular echo characteristics of differing objects.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a method and apparatus or tool which is used to create a reamed hole for installing a conduit or pipe. The tool and method is well suited for use with directional boring machines, but can be adapted for use with other mechanical devices (such as a push rod machine) that are used to create subsurface excavations for the purpose of installing conduit or pipe.
[0002] Often in the past in order to install a new pipe or conduit it has been necessary to excavate from the surface down to the depth of the desired installation and then replace the material that was excavated. This method is often referred to as “open trench excavation” and is not desirable in many locations due to impact to the general public, to pass under obstacles such as roads, environmental concerns and other issues. Devices and tools have been developed in the past by others in order to allow for the installation of underground pipes and conduits without the necessity of open trenching. This method is generally referred to as “trenchless” installation and includes many varied techniques. The primary types of trenchless construction for new pipe and conduit installations involve directional boring machines, push rod machines, pipe ramming devices, auger boring machines, and tunneling methods all known in the art. There are tools and devices known in the utility construction industry for creating reamed holes for the purpose of installing conduits and pipes and, in particular, there are several apparatuses that are used in the directional boring industry. However, no devices are available that embody or use the aspects of the applied for apparatus. The and advantages of the applied for apparatus and method will significantly improve the efficiency and effectiveness of underground utility construction by establishing a better method for creating a trenchless reamed hole for installing pipe and providing a tool for use with the method.
[0003] The apparatus and method is best suited for use with directional boring machines, although it may be used with other devices as discussed later. Directional boring machines, in general, utilize a length of drill pipe with at least a small hole passing through longitudinally from one end to the other. Sections of drill pipe are connected and then advanced through the earth in segmental fashion. This segmented connection of drill pipe is called a drill string. Various methods and apparatuses are used to guide the drill pipe into the desired position. Directional boring machines are typically positioned at the surface and advance the drill pipe down to the depth of the desired bore. Often a fluid mixture is passed through the drill string in order to assist in the drilling process. After the initial drill string is in place a hole opening device, typically referred to as a reamer, is attached and used to create a hole that will accept the desired conduit or pipe.
[0004] In the past, in general, the primary methods of creating a reamed hole in directional boring applications has been to use a reamer fixedly mounted to the length of drill pipe. The reamer is then, typically, rotated and pulled through the ground. Often an aqueous solution is pumped through the drill string in order to help create a mixture of the existing soil and special added agents that assist in making a slurry that advantageously allows for easier installation of pipe or conduit product. A typical reamer's primary function is often to either chop up the existing soil in the path of the desired bore hole and mix it with the added agents or to compact the existing soil in the path of the desired bore hole. Sometimes reamers are used to combine both compaction and cutting/mixing. Since soil and earth conditions vary greatly, different tools are used and selected based on operator experience and anticipated conditions. Though there are existing tools available, none use a reaming mechanism that incorporates the dual mixing and cutting functions of the applied for apparatus.
[0005] Push rod machines incorporate some of the same overall characteristics as directional boring, but typically are placed in an excavation at one end of the desired bore instead of at the surface. Typically a section of pipe is connected in segmental fashion and advanced through the ground. Again, there are various methods to get the rods in the desired place. Often the overall efficiency of the machines and the machine tooling limits the overall length that can be done at one time. The use of push rod machines has diminished in the recent past, but they are still sometimes used and advances in push rod technology, such as ways to ream holes more efficiently, could lead to more prominent use in the future.
[0006] The apparatus utilized for practicing the method of installation of conduit or pipe is novel and unique in that it ideally uses either a plurality of stems or a mechanical drive mechanism in conjunction with a single stem to create a much more effective method of both mixing and reaming the soil. This better method and tool therefore decreases the time and increases the efficiency of the installation of conduits and pipe. In addition to these benefits, it is possible to utilize this method and the embodiments of the apparatus to create rectangular, ovoid or even irregularly shaped reamed holes which may be desirable for some installations. There are currently no available apparatuses in the directional boring industry that allow for the creation of other than a generally round reamed hole.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention is an improved apparatus and method of creating a bored hole below the surface of the earth. More specifically it is a method of creating a bored hole using a special backreaming device connected to a directional boring machine or push rod machine or other mechanical drive device. The method includes the use of a tool that incorporates a dual reaming device that is driven either by a plurality of drill stems or by using mechanical means to differentiate torque to drive mechanisms (ideally gears) from a single stem. The stems will ideally be connected to a directional boring machine but can be connected to another drive mechanism.
[0008] The apparatus consists of an exterior reaming part and an interior mixing part. In one preferred embodiment of the invention the exterior part of the apparatus is round and the interior portion of the apparatus is made up of a variety of mixing items. In the preferred embodiment, the outer shell of the apparatus can be turned at a lower speed (and generally with greater torque due to being connected to a larger drill pipe string) and the interior can be turned at a faster speed to increase mixing of fluid and soil. Sometimes it may be desirable to turn the exterior portion at a faster rate and the interior portion at a slower rate. This combination of a primary action of outer cutting and inner mixing provides several benefits over conventional reaming. Conventional reamers in general must both cut and mix the soil and fluids and therefore a sacrifice is typically made with respect to either the mixing efficiency of the device, the cutting efficiency of the device or both the mixing and cutting efficiency. The desired apparatus improves both the mixing capability of the reaming device and the cutting capability.
[0009] In another embodiment of the invention the interior mixing portion can be turned counter to the exterior shell portion. This, in effect, multiplies the rotational torque applied to the soil in the interior of the shell (by double the amount or more), allowing for better mixing capability and quality.
[0010] Another embodiment of the device incorporates different shapes for the outer shell. The preferred exterior shell shapes are round, polygonal and ovoid shaped, though other shapes can be used. The round shape will likely be the most common commercially used shape due to the nature of underground utility installations. The polygonal shape (often rectangular) can be used for utility construction in areas where maximizing the use of the available space is essential, such as in corridors that are extremely congested with other utilities, though there will likely be other uses. In particular a square shape can provide the maximum cross-sectional area for a reamed hole with the smallest bisected distance. This will allow for the installation of the maximum number of separate conduits in the smallest possible space. The ovoid shape, in the general form of egg shaped, is well suited for sewer main installations due to the flow characteristics of the installed pipe, though other uses can be found.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The preferred embodiment of the present invention is described in detail below with reference to the attached drawings, wherein:
[0012] FIG. 1 is a schematic view of a directional machine in a typical application with a set of drill pipe in place;
[0013] FIG. 2 is a schematic view of the directional boring machine forming a bore hole using the present invention dual reaming apparatus in accordance with the method of the present invention;
[0014] FIG. 3 is an enlarged sectional view of the round shell embodiment of the present invention apparatus connected to a dual stem directional boring machine;
[0015] FIG. 4 is an enlarged sectional view of the round shell embodiment of the present invention apparatus using a single stem directional boring machine;
[0016] FIG. 4 is an enlarged sectional view of the polygonal shell embodiment of the present invention apparatus connected to a dual stem directional boring machine;
[0017] FIG. 5 is an enlarged sectional view of the ovoid shaped shell embodiment of the present invention apparatus connected to a dual stem directional boring machine.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring to the drawings, and first to FIG. 1 and FIG. 2 , the environment in which the apparatus and method is used with a directional boring machine. The boring machine is generally indicated by 1 and shown resting on the earth's surface 4 , typically on tracks 6 . By using the boring machine 1 the set of drill pipes 3 stored in a drill rack 2 are connected in a segmental fashion and advanced through the ground to a desired point 7 . For the purposes of the FIG. 1 , this point 7 is shown below the earth's surface 4 in an excavated pit 8 . This desired point 7 can be at a point at or near the earth's surface depending on the situation as shown in FIG. 2 . The dual reaming apparatus 5 is attached to the drill pipe string 3 and used to create a reamed hole 9 capable of accepting a desired pipe or conduit as shown in FIG. 2 .
[0019] Referring to FIGS. 1, 2 and 3 , the boring machine 1 utilizes mechanical and hydraulic energy to turn the drill string 3 and thus the dual reaming apparatus 5 . A mixture of aqueous solution is forced down the drill string 3 . The dual reaming device 5 is then turned and pulled back through the earth causing the soil in the path of the dual reaming device to be mixed with the fluid being forced down the drill string. The outer shell 12 of the dual mixing device can be turned to cut the existing soil. This cut soil 20 falls into the interior of the outer shell and the inner section of the dual reaming device 13 increases the mixing of the existing soil 20 and fluid 23 that is added through a single or plurality of fluid jet holes 24 . The use of a single or plurality of assisting mixing wings 14 of various shapes and lengths extend off of the inner section of the device. The interior mixing device can be connected directly to the interior stem of a dual stem directional boring system and cantilevered without a connection such as that shown in 15 and 16 , but problems may arise due to torque and impact of soil and earth material. The preferred embodiment incorporates a connection utilizing a mechanical swivel 16 and sealed bearing assembly 15 . This allows the interior mixing portion 13 to turn independently of the outer shell 12 while still providing passive or active support of the interior mixing portion 13 .
[0020] Added efficiency can be achieved by the addition of multiple fluid jet ports 24 at various locations in order to concentrate the stream of fluid 23 to desired points. A distribution line 21 can be added to direct a portion of fluid 23 directly to an exterior point 22 of the outer shell 12 . Fluid lubrication holes 29 may be added to exterior shell 12 as well. Cutting teeth 11 added to the outer shell can add efficiency for the initial cut of the earth for the desired reamed hole. Pipe can be connected to a commercially available swivel and pull head and hooked directly to the reaming device via a plate 27 and connection 28 located at the rear of the device.
[0021] Connection of the apparatus to a dual stem directional boring machine can be accomplished by standard methods such as using threaded connections 19 and 31 for the exterior stem and slotted connections for the interior stem 30 or threaded connections for both the exterior and interior stems 32 .
[0022] FIG. 4 shows the apparatus utilizing a dual reamer apparatus connected to a single stem directional boring machine drill string 40 . Standard directional boring machines that use a single stem drill string 40 utilize threaded connections 41 . The apparatus is connected to the drill string 40 using a threaded end 42 . Torque provided to the drill string via mechanical power at the boring machine turns the exterior shell 43 of the apparatus. Ideally gears 50 (or a camshaft) in a planetary drive 46 ideally located in the interior of the apparatus convert the rotational torque provided by the revolving outer shell into usable energy to turn the interior mixing section 48 . A sealed connection 45 prevents intrusion of the fluid 56 and soil 54 into the planetary drive 46 . The interior section 48 can be gear so as to turn at various rotational speeds with respect to the outer section 43 and can be reversed with respect to the revolution of the outer section 43 if so desired. Various mixing wings are used to mix the soil 54 cut by the outer section 43 and the fluid 55 disbursed through nozzles 56 at various locations. Fluid is delivered via the drill string 40 and a connection that passes the fluid through the planetary drive 49 and 51 . Ideally a mechanical swivel 53 and bearing assembly 52 can be used to reduce problems associated with torque and impact for the interior section 48 , although the interior section could be cantilevered with the addition of a bearing assembly located near the planetary drive 46 .
[0023] FIG. 5 provides a sectional side view and front view of the apparatus that can be used to create a polygonal (in this case a square) reamed hole. This view shows the apparatus connected to a dual stem directional boring machine drill string 66 , although it may be attached to other drill strings with some modifications. The interior section of the device ideally rests on a bearing assembly 68 and is ultimately provided with torque via the drill string. Fluid 73 is forced down the drill string and out nozzles 72 at various locations. The outer shell 67 does not rotate and is kept in the desired position via the use of stabilizing wings 74 located at various positions on the exterior of the outer shell. The interior section is rotated and mixing/cutting wings 69 are used to cut and mix the soil. The configuration of the mixing/cutting wings may be varied based on anticipated soil types. The fluid 73 and soil 74 in the desired reamed path is mixed to a slurry for ease of installation of the desired conduit(s) or pipe(s). A bearing assembly 71 and swivel 70 at the rear of the apparatus should ideally be used to reduce impact and torque problems with the interior section.
[0024] FIG. 6 provides a sectional front view of the ovoid shaped apparatus.
[0025] From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
[0026] Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative of applications of the principles of this invention, and not in a limiting sense.
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A method and apparatus for creating a reamed hole below the surface are disclosed. The reaming apparatus is arranged to be connected to one or more boring stems and has an interior section and an exterior section. The interior section is rotatable independently of the exterior section. Reamed holes of various cross-sections can be produced by appropriate selection of the cross-section of the exterior section.
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TECHNICAL FIELD
The invention relates to disc brakes and more particularly relates to actuated disc brake systems for motor vehicles with brake calipers and an actuating unit.
BACKGROUND OF THE INVENTION
A disc brake of this particular type is known from EP-D394 238 B1. Here, the actuating unit consists of an electric motor working with a planetary gear, and its planetary wheels powering a ring wheel. The ring wheel's rotational motion is transmitted, via bearing elements, to an actuating bush, thus causing its axial displacement or shift which, in return, causes the actuating element's respective friction lining to interact with the disc brake. The electric motor and planetary gear are positioned side by side in the disc brake's path of actuation. One disadvantage of all known, electromechanically actuated, disc brakes is the considerable axial extension of the actuating unit.
It is the intent of the submitted invention to improve on an electromechanical disc brake of the type mentioned above, with special emphasis put on reducing the axial dimensions of the actuating mechanism.
Its conceptual problem is solved in that the electric motor's rotor is of ring-shaped design, radially surrounding the reducing gear. The functionality of such an electromechanically actuated disc brake is unique in its strong dynamics of brake actuation and extremely compact design, allowing the transmission of high-density, mass-intensive braking power.
Practical application of the invention calls for the reducing gear to be a threaded roller pinion, with its threaded nut transmitting power to the rotor. An economically advantageous refinement has the threaded roller pinion designed as one featuring axial return of the rollers. It is of special convenience to have the actuating element represented by the spindle of the threaded roller pinion.
In order to achieve a considerable reduction in the electric motor's required torque, the power exchange between rotor and threaded nut is conducted by means of a planetary gear, with its sun wheel deployed at the rotor, while the planetary wheels are located at the threaded nut. The internal toothing of the brake calipers represents the hollow wheel of the planetary gears, interacting with the planetary wheels. It is of advantage to have available, between rotor and gear nut, a needle bearing and ball bearing configuration, under which the radial external track of the ball bearing is situated in the rotor and the radial internal track is, at least partially, situated in the threaded nut. Such arrangement makes possible a reduction in electric waste and an enlargement of the rotor's angle--quite advantageous for deployment of the threaded spindle as a requirement for the lining's positioning.
The smooth transmission of the electric motor's actuating power is achieved through cooperation of the spindle with a power transmission plate which is installed on the direct-actuated side of the friction lining.
A substantial reduction in efficiency loss, due to friction being present in the threaded roller pinion, is realized by installing a plunger rod (or pressure bar) between the threaded spindle and power transmission plate.
An even transmission of compressive forces between threaded spindle and power transmission plate is achieved by partially installing the plunger rod inside the threaded spindle, and securing it by way of two spherical caps. The first of these is intended to be mounted in the threaded spindle, with the other on the axial extension of the power transmission plate. Ideally, the first of the spherical caps should be mounted at the center point of the threaded spindle's axial length, and/or within the space defined by the spindle's thread rollers.
A further characteristic is the establishment of a connection of torsional strength between thread spindle and the power transmission plate, allowing smooth transmission of torsional momentum resulting from brake application force. It is achieved through the deployment of a metallic bellows between the threaded spindle and power transmission plate, which is placed coaxially to the plunger rod, and firmly attached to the threaded spindle and power transmission plate, preferably by welding.
The electric motor's hollow shaft, integrated in the actuating unit, is optimally positioned because the screw threaded nut exhibits radial expansion, enabling it to be supported by a radial bearing (it being designed as a cross shaft bearing and/or four-point bearing). The bearing's inner ring should be determined by the circumferential dimension of the expansion. Its ability to absorb high axial and radial forces and stalls or lock-ups adds to a further stabilization of the hollow shaft.
The electric motor has the versatility to operate as either a permanent magneto-excited, electronically commutating electric motor (torque), or a connected reluctance motor (SR).
The mentioned motor types are especially suitable for generating high torque when in standstill mode.
To find a good location for placement of the rotor, particularly under utilization of the mentioned torque motors, the invention provides for a contact-free resolver (angle indicator), which works in concert with the reducing gear and pinpoints the actuating element's location. The resolver may be made up of two rings with electric windings, spaced by an air gap. One of the rings, preferably the radial inner ring, should be firmly attached to the rotor, while the other is installed in the housing, with torsional strength intact. Such a resolver affords high definition; hence, a targeted braking process of optimal increments eases the precise positioning of the friction lining.
The resolver's initial signal can at the same time be used for commutation of the torque motor.
Another characteristic variation of the concept is available, whereby a readjusting spring is inserted between the screw thread nut and the spindle which, following the rotational motion, allows the thread nut a counter-rotational motion step. The feature prevents the brake to remain in its actuated state, brought about by its own hysteresis, e.g. after power failure. The remaining brake impulses are essentially eliminated.
Another characteristic is the presence of a torsion retainer/equalizer, located between the power transmission plate and the first friction lining. For example, the deployment of a lining support spring, installed on hydraulic-actuated disc brakes with friction lining, can serve as a torsion retainer.
To ensure confirmation of contact between the friction lining and disc brake, contact sensor pins are embedded in the friction lining to measure electric resistance between the disc and lining. They further serve the purpose of monitoring the lining's wear and tear.
To effectively protect the actuating mechanism from soilage, like splashing water, an elastic sealer element is located between the housing and actuating element (spindle).
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 A cross section of the first embodiment of the electromechanically actuated disc brake of the present invention.
FIG. 2 Complementary to FIG. 1, a second version of the subject.
FIGS. 3,4,5 The third, fourth, and fifth versions of the subject, complementary to FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to FIG. 1 which shows the disc brake as a floating caliper disc brake. It is composed essentially of a sliding caliper 1, mounted in a rigid frame (not shown here) and an actuating unit 2, with its housing 8 attached to caliper 1 (again, mounts not shown). A set of friction linings 4 and 5 one positioned on caliper 1 in a manner so as to be in juxtaposition to the left and right flat surfaces of disc brake 3.
Subsequent descriptions will refer to friction lining 4, shown right in the drawing, as first friction lining, with friction lining 5 designated second.
While contact of friction lining 4 with disc brake 3 is under direct control of actuating unit 2 and its actuating element 30, the reactive pressure forces springing from actuation of brake caliper 1, will cause lining 5 to press against the opposite surface of brake disc 3.
The previously mentioned actuating unit 2 is composed of an electric motor 6, which in the example is represented as a permanent magneto-excited, electronically commutating (torque) motor, with stator 9 rigidly fixed in housing 8 and rotor 10 (or hollow shaft) being fermed by ring-shaped support 28 which is equipped with several permanent magneto-segments 29. Between torque motor 6 and above mentioned actuating element 30 (preferably deployed coaxially to motor 6), a reducing gear is positioned. It is displayed in the example as threaded roller pinion 11 and 14, and consists of a screw threaded nut 11 and a threaded spindle 14. Parallel axis threaded rollers 12 and 13 are arranged in threaded nut 11. The threaded rollers will, during rotational motion of threading nut 11, rotate in planetary mode without axial shift, and will set in axial motion the threaded spindle 14. Radial guidance of threaded rollers 12 and 13 is assured by two guide disks 40, located at the ends of threaded rollers 12 and 13, and toothed wheel rims (not shown).
The mentioned actuating unit 2 consists of electric motor 6, shown in the example as permanent magneto-excited, electronically commutating (torque) motor, with its stator rigidly fixed in housing 8. Its rotor 10 and/or hollow shaft is formed by a ring-shaped support 28, equipped with several permanent magneto-segments 29. Between torque motor 6 and previously mentioned actuating element 30 (preferably arranged in coaxial fashion to motor 6), a reducing gear is installed, which is displayed as threaded roller pinion 11 to 14. The threaded roller pinion 7 consists of a threaded nut 11 and a threaded spindle 14, within which threaded unit 11 is axially parallel to threaded rollers 12,13. These will, during rotational motion of threaded nut 11, rotate in planetary fashion without axial shift and will set in axial motion threaded spindle 14. Two guidance discs 40 are arrayed at the ends of threaded rollers 12,13 to provide radial guidance. The additional toothed wheel rims are not shown.
The most suitable arrangement has rotor 10 of torque motor 6 connected under torsional strength to threaded nut 11 by inclusion of a feather key 39. Threaded spindle 14 constitutes actuating element 30, which under assistance of power transmission plate 24 actuates the first friction lining 4. A torsion retainer 25 is preferably inserted between power transmission plate 24 and the first friction lining 4. Torsion retainer 25 consists of a pin embedded in friction lining 4, and will plug into an inlet allowed for in power transmission plate 24. A radial bearing supported by caliper 1 controls reducing gear 7 and hollow shaft or rotor 10. The radial bearing in the example shown is a cross roller bearing 16. It consists of a bearing's external ring 18 (shown in FIG. 1 in divided form), a bearing's internal ring arrayed on a collar-shaped radial expansion 15 of threaded nut 11, and several cylinder rollers 19 arrayed between bearing rings 17,18. The bearing rings 17,18 form four interconnected tracks, showing at a 45° pitch relative to the bearing level, and/or two sets of twin tracks, offset by 90°, where cylinder rollers 19 (in X-arrangement) alternately roll off on one of the twin tracks.
Because the used cross roller bearing can handle any combination of axial, radial, and stalled loads, a second bearing is redundant.
A four-point bearing may replace a cross roller.
To position threaded roller pinion 7 exactly and control signals for electronic commutation of torque motor 6, housing 8 in actuating unit 2 contains a resolver 20.
In the given example, a resolver consists of two coaxial rings 21,22, which are equipped with electric windings and are spaced by an air gap. The radial internal ring 21 is linked to threaded nut 11 by means of an intermediate member 61 while the other ring 22 is installed for torsional strength in housing 8.
For the purpose of clearly recognizing contact between friction linings 4,5 and brake disc 3, the former have been equipped with contact pins 26. The interior of housing 8 is protected by a cover 31, located nearby resolver 20, and is additionally protected by an elastic, membrane-like sealer 27 to guard against soilage from splashing water. Sealer 27 is best inserted between actuating unit 30 or threaded spindle 14, and a retaining ring 32, axially positioned on the bearing's external ring 18.
To dissipate generated heat of torque motor 6 operations, housing 8 is equipped with large-scale cooling ribs 33.
The embodiment of FIG. 2 shows the actuating unit 2 being powered by a connected reluctance motor (SR-motor). The bearing's internal ring or the radial interior twin tracks of mentioned cross roller bearing is formed by the circumferential dimension of expansion 15 of threaded nut 11. Because of its single-piece design, the internal bearing ring with threaded nut 11 is of higher operating precision, and less installation is involved, with modular assembly possible. The reducing gear 7 is, in FIG. 2, displayed as a threaded roller pinion with axial return of rollers 34, which are positioned in a cage 35, holding them parallel to threaded spindle 14 and equidistant to the spindle's circumference. The threaded rollers 34 conclude their circuit to arrive at an axial nut (not shown) inside threaded nut 11 to separate from both threaded nut 11 and the spindle's thread. The axial return of rollers 34 to their original position is controlled by cams (not shown) inside the nut's thread. Rotor 10 of the SR motor is made up of several ring-shaped rotor metal units 36, attached across on threaded nut 11, and interlocking for torsional strength. The second version of the invention's SR motor is resistant to higher temperatures, which eliminates the need for cooling ribs on housing 8 of actuating unit 2.
To prevent remaining brake momentum, after the act of braking, to affect the wheel if a failure of control electronics occurs through hysteresis of the actuating unit, a spiral-shaped readjusting spring 23 is provided which installs between threaded nut 11 and a cover, closing off the motor housing. The readjusting spring moves the threaded nut 11 counter to the actuated rotational direction, enabling friction linings 4,5 to lift off brake disc 3. For uniform initiation of actuating forces on friction linings 4,5 in housing 8 of the actuating unit, caliper 1 must be massively dimensioned. To reduce flexural impact of friction linings 4,5 on housing 8 of actuating unit 2, it is recommended to design caliper 1 as a framed caliper. Thus, only pulling forces enter the housing, without imposing flexural tension within the support base of actuating unit's 2 bearing.
The invention's third embodiment demonstrates the transmission of pressure forces between threaded spindle 14 and power transmission plate 24 via threaded spindle 14, partially located inside plunger rod 41, and being mounted in two spherical caps 42. The first is positioned at the center of threaded spindle's 14 axial length (between threaded rollers 12,13) while the second spherical cap 43, being nearer to friction lining 4 rests in the axial extension 44 of power transmission plate 24. Furthermore, between power transmission plate 24 and/or its extension 44 and threaded spindle 14, a metallic bellows 45 is welded to both parts, which provides a connection of torsional strength for transmission of torsional momentum, resulting from the brake application forces generated by the threaded spindle.
Now referring to FIG. 4, a reduction of the required motor momentum is achieved in the fourth embodiment of the present invention by purposeful integration of a planetary gear 46,47,48,49. Deployed most effectively between rotor 10 and threaded nut 11, the planetary gear consists of a sun wheel 46, formed on rotor 10 in external toothed arrangement 55, several planetary wheels (two of them depicted with reference numbers 47 & 48) and a hollow wheel 49, formed by internal toothing 50 in caliper 1. The mounting of the rotor 10 on threaded nut 11 takes place by combination of a schematic needle bearing 51 and a ball bearing 52, with its radial external track 53 contained in rotor 10, while its internal track 54 is laid out partially at the end of threaded nut 11, and partially on bush 60. This facilitates the selection of a spindle thread with steeper pitch for greater effect.
OPERATION OF THE DEVICE
When the stator 9 is excited, the rotor 10 starts rotating. Presuming the direction of the stator's rotation be counterclockwise in a view from the right side of the drawing. Then the lower part of the rotor 10 moves into the plane of the picture, while the upper part moves out of the picture plane. With its external toothed arrangement 55, the rotor engages the planetary wheels 47 and 48 which consequently rotate in a clockwise direction. Thus, they move along the internal toothing 50 of the static hollow wheel 49 in a counterclockwise direction. Since the axles of the planetary wheels 47 and 48 are born on the collar-shaped radial extension 15 of the threaded nut 11, the threaded nut 11 will rotate along with the planetary wheel axles in a counterclockwise direction. This causes the threaded rollers 12 and 13 to rotate counterclockwise as well. The threaded rollers 12 and 13 are provided with right-hand threads which, during a counterclockwise rotation, shift the threaded spindle 14 to the left, for it is secured against rotation. In this way, brake lining 4 is brought into contact with the brake disc, while brake lining 5 is pressed against the brake disc by reactive pressure forces as described in connection with FIG. 1. The brake linings are released by a clockwise rotation of the rotor 10.
FIG. 5 of the drawing demonstrates the invention's fifth embodiment, when electric motor 6 is designed as an externally operating motor. In the next example shown, the electric motor's 6 stator 90 is fused locally to cylindrical part 56 in housing 8. Operating heat is released via part 56 to housing 86. Rotor 100, enclosing stator 90, is linked to threaded nut 11 per bell-shaped flange 57, and thus mounted on the same side. To assure utilization of even small air gaps between rotor 100 and stator 90, the rotor 100 on the drawing's right side is mounted with a radial bearing 58 in housing 8, which by use of a (Belleville) spring washer 59 finds axial support on housing 8.
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An electromechanically actuated disc brake system for motor vehicles comprising a floating caliper and an actuating unit mounted with the caliper. The actuating unit is an electric motor which, by interpolation of a reducing gear, powers an actuating element, which in turn controls one of two sliding friction linings mounted inside the brake caliper, to interact with the disc brake. With the intent to reduce axial dimensions of the actuating unit, the present invention includes an electric motor with a rotor of ring-shaped design to radially surround the reducing gear.
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[0001] This application is a continuation of U.S. patent application Ser. No. 14/623,730, filed Feb. 17, 2015, now U.S. Pat. No. 9,228,327, which is a continuation of U.S. patent application Ser. No. 13/048,445, filed Mar. 15, 2011, now U.S. Pat. No. 8,474,476, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/313,902, filed Mar. 15, 2010, and U.S. Provisional Patent Application Ser. No. 61/313,918, filed Mar. 15, 2010, the entire disclosures of which are incorporated by reference herein.
[0002] This application is also related to U.S. Pat. No. 8,042,565, U.S. Pat. No. 7,472,718, and U.S. Pat. No. 7,730,901, the entire disclosures of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0003] Embodiments of the present invention are generally related to contamination proof hydrants that employ a venturi that facilitates transfer of fluid from a self-contained water storage reservoir.
BACKGROUND OF THE INVENTION
[0004] Hydrants typically comprise a head interconnected to a water source by way of a vertically oriented standpipe that is buried in the ground or interconnected to a fixed structure, such as a roof. To be considered “freeze proof” hydrant water previously flowing through the standpipe must be directed away from the hydrant after shut off. Thus many ground hydrants 2 currently in use allow water to escape from the standpipe 6 from a drain port 10 located below the “frost line” 14 as shown in FIG. 1 .
[0005] Hydrants are commonly used to supply water to livestock that will urinate and defecate in areas adjacent to the hydrant. It follows that the animal waste will leach into the ground. Thus a concern with freeze proof hydrants is that they may allow contaminated ground water to penetrate the hydrant through the drain port when the hydrant is shut off. More specifically, if a vacuum, i.e., negative pressure, is present in the water supply, contaminated ground water could be drawn into the standpipe and the associated water supply line. Contaminants could also enter the system if pressure of the ground water increases. To address the potential contamination issue, “sanitary” yard hydrants have been developed that employ a reservoir that receives water from the standpipe after hydrant shut off.
[0006] There is a balance between providing a freeze proof hydrant and a sanitary hydrant that is often difficult to address. More specifically, the water stored in the reservoir of a sanitary hydrant could freeze which can result in hydrant damage or malfunction. To address this issue, attempts have been made to ensure that the reservoir is positioned below the frost line or located in an area that is not susceptible to freezing. These measures do not address the freezing issue when water is not completely evacuated from the standpipe. That is, if the reservoir is not adequately evacuated when the hydrant is turned on, the water remaining in the reservoir will effectively prevent standpipe water evacuation when the hydrant is shut off, which will leave water above the frost line.
[0007] To help ensure that all water is evacuated from the reservoir, some hydrants employ a venturi system. A venturi comprises a nozzle and a decreased diameter throat. When fluid flows through the venturi a pressure drop occurs at the throat that is used to suction water from the reservoir. That is, the venturi is used to create an area of low pressure in the fluid inlet line of the hydrant that pulls the fluid from the reservoir when fluid flow is initiated. Sanitary hydrants that employ venturis must comply with ASSE-1057, ASSE-0100, and ASSE-0152 that require that a vacuum breaker or a backflow preventer be associated with the hydrant outlet to counteract negative pressure in the hydrant that may occur when the water supply pressure drops from time-to-time which could draw potentially contaminated fluid into the hydrant after shut off. Internal flow obstructions associated with the vacuum breakers and backflow preventers will create a back pressure that will affect fluid flow through the hydrant. More specifically, common vacuum breakers and backflow preventers employ at least one spring-biased check valve. When the hydrant is turned on spring forces are counteracted and the valve is opened by the pressure of the fluid supply, which negatively influences fluid flow through the hydrant. In addition an elongated standpipe will affect fluid flow. These sources of back pressure influence flow through the venturi to such a degree that a pressure drop sufficient to remove the stored water from the reservoir will not be created. Thus to provide fluid flow at a velocity required for proper functioning of the venturi, fluid diverters or selectively detachable backflow preventers, i.e., those having a quick disconnect capability, have been used to avoid the back pressure associated with the vacuum breakers of backflow preventers. In operation, as shown in FIG. 2 , the diverter is used initially for about 45 seconds to ensure reservoir evacuation. Then, the diverter is disengaged so that the water will flow through the backflow preventer or vacuum breaker. The obvious drawback of this solution is that the diverter must be manually actuated and the user must allow water to flow for a given amount of time, which is wasteful.
[0008] Further, as the standpipe gets longer it will create more backpressure, i.e., head pressure, that reduces the flow of water through the venturi, and at some point a venturi of any design will be unable to evacuate the water in the reservoir. That is, the amount of time it takes for a hydrant to evacuate the water into the reservoir depends on the height/length of the standpipe as well as the water pressure. The evacuation time of roof hydrants of embodiments of the present invention, which has a 42″ standpipe, is 5 seconds at 60 psi. The evacuation time will increase with a lower supply pressure or increased standpipe length or diameter. Currently existing hydrants have evacuation times in the 30 second range.
[0009] Another way to address the fluid flow problem caused by vacuum breakers is to provide a reservoir with a “pressure system” that is capable of holding a pressure vacuum that is used to suction water from the standpipe after hydrant shut off. During normal use the venturi will evacuate at least a portion of the fluid from the reservoir. Supply water is also allowed to enter the reservoir which will pressurize any air in the reservoir that entered the reservoir when the reservoir was at least partially evacuated. When flow through the hydrant is stopped, the supply pressure is cut off and the air in the reservoir expands to created a pressure drop that suctions water from the standpipe into the reservoir. If the vacuum produced is insufficient, which would be attributed to incomplete evacuation of the reservoir, water from the standpipe will not drain into the reservoir and water will be left above the frost line.
[0010] Other hydrants employ a series of check valves to prevent water from entering the reservoir during normal operations. Hydrants that employ a “check system” uses a check valve to allow water into or out of the reservoir. When the hydrant is turned on, the check valve opens to allow the water to be suctioned from the reservoir. The check also prevents supply water from flowing into the reservoir during normal operations, which occurs during the operation of the pressure vacuum system. When the hydrant is shut off, the check valve opens to allow the standpipe water to drain into the reservoir. One disadvantage of a check system is that it requires a large diameter reservoir to accommodate the check valve. Thus a roof hydrant would require a larger roof penetration and a larger hydrant mounting system, which may not be desirable.
[0011] Another issue associated with both the pressure vacuum and check systems is that there must be a passageway or vent that allows air into the reservoir so that when a hydrant is turned on, the water stored in the reservoir can be evacuated. If the reservoir was not exposed to atmosphere, the venturi would not create sufficient suction to overcome the vacuum that is created in the reservoir.
SUMMARY OF THE INVENTION
[0012] It is one aspect of embodiments of the present invention to provide a sanitary and freeze proof hydrant that employs a venturi for suctioning fluid from a fluid storage reservoir. As one of skill in the art will appreciate, the amount of suction produced by the venturi is a function of geometry. More specifically, the contemplated venturi is comprised of a nozzle with an associated throat. Water traveling through the nozzle creates an area of low pressure at or near the throat that is in fluid communication with the reservoir. In one embodiment, the configuration of the nozzle and throat differs from existing products. That is, the contemplated nozzle is configured such that the venturi will operate in conjunction with a vacuum breaker, a double check backflow preventer, or a double check backflow prevention device as disclosed in U.S. Patent Application Publication No. 2009/0288722, which is incorporated by reference in its entirety herein, without the need for a diverter. Preferably, embodiments of the present invention are used in conjunction with the double check backflow prevention device of the '722 publication as it is less disruptive to fluid flow than the backflow preventers and vacuum breakers of the prior art.
[0013] While the use of a venturi is not new to the sanitary yard hydrant industry, the design features of the venturi employed by embodiments of the present invention are unique in the way freeze protection is provided. More specifically, current hydrants employ a system that allows water to bypass a required vacuum breaker. For example, the Hoeptner Freeze Flow Hydrant employs a detachable vacuum breaker and the Woodford Model S3 employs a diverter. Again, fluid diversion is needed so that sufficient fluid flow is achieved for proper venturi functions. The venturi design of sanitary hydrants of the present invention is unique in that the venturi will function properly when water flows through the vacuum breaker or double check backflow preventer—no fluid diversion at the hydrant head is required. This allows the hydrant to work in a way that is far more user friendly, because the hydrant is able to maintain its freeze resistant functionality without requiring the user to open a diverter, for example. Embodiments of the present invention are also environmentally friendly as resources are conserved by avoiding flowing water out of a diverter.
[0014] It is another aspect of the embodiments of the invention is to provide a hydrant that operates at pressures from about 20 psi to 125 psi and achieves a mass flow rate above 3 gallons per minute (GPM) at 25 psi, which is required by code. One difficult part of optimizing the flow characteristics to achieve these results is determining the nozzle diameter. It was found that a throat diameter change of about 0.040 inches would increase the mass flow rate by 2 GPM. That same change, however, affects the operation of the venturi. For example, hydrants with a nozzle diameter of 0.125 inches will provide acceptable reservoir evacuation but would not have the desired mass flow rate. A 0.147 inch diameter nozzle will provide an acceptable mass flow rate, but reservoir evacuation time was sacrificed. In one embodiment of the present invention a venturi having a nozzle diameter of about 0.160 inches is employed.
[0015] It is another aspect of the present invention to provide a nozzle having an exit angle that facilitates fluid flow through the venturi. More specifically, the nozzle exit of one embodiment possesses a gradual angle so that fluid flowing through the venturi maintains fluid contact with the surface of the nozzle and laminar flow is generally achieved. In one embodiment the exit angle is between about 4 to about 5.6 degrees. For example, nozzle exit having very gradual surface angle, e.g. 1-2 degrees, will evacuate the reservoir more quickly, but would require an elongated venturi. Thus, an elongated venturi may be used to reduce back pressure associated with the venturi, but doing so will add cost. The nozzle inlet may have an angle that is distinct from that of the exit to facilitate construction of the venturi by improving the machining process.
[0016] It is thus one aspect of the present invention to provide a sanitary hydrant, comprising: a standpipe having a first end and a second end; a head for delivering fluid interconnected to said first end of said standpipe; a fluid reservoir associated with said second end of said standpipe; a venturi positioned within said reservoir and interconnected to said second end of said standpipe, said venturi comprised of a first end, which is interconnected to said standpipe, and a second end associated with a fluid inlet valve with a throat between said first end and said second end of said venturi; a bypass tube having a first end interconnected to a location adjacent to said first end of said venturi and a second end interconnected to a bypass valve, said bypass valve also associated with said second end of said venturi, wherein when said bypass valve is opened, fluid flows from said inlet valve, through said bypass tube, through said standpipe, and out said hydrant head; and wherein when said bypass valve is closed, fluid flows through said venturi, thereby creating a pressure drop adjacent to said throat that communicates with said reservoir to draw fluid therefrom.
[0017] It is another aspect to provide a method of evacuating a sanitary hydrant, comprising: providing a standpipe having a first end and a second end; providing a head for delivering fluid interconnected to said first end of said standpipe; providing a fluid reservoir associated with said second end of said standpipe; providing a venturi positioned within said reservoir and interconnected to said second end of said standpipe, said venturi comprised of a first end, which is interconnected to said standpipe, and a second end associated with a fluid inlet valve with a throat between said first end and said second end of said venturi; providing a bypass tube having a first end interconnected to a location adjacent to said first end of said venturi and a second end interconnected to a bypass valve, said bypass valve also associated with said second end of said venturi, wherein when said bypass valve is opened, fluid flows from said inlet valve, through said bypass tube, through said standpipe, and out said hydrant head; and wherein when said bypass valve is closed, fluid flows through said venturi, thereby creating a pressure drop adjacent to said throat that communicates with said reservoir to draw fluid therefrom initiating fluid flow through said head by actuating a handle associated therewith; actuating a bypass button that opens the bypass valve such that fluid is precluded from entering said venturi; actuating said bypass button to close said bypass valve; flowing fluid through said venturi; evacuating said reservoir; ceasing fluid flow through said hydrant; and draining fluid into said reservoir.
[0018] The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention. Moreover, references made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the Invention. Additional aspects of the present invention will become more readily apparent from the Detail Description, particularly when taken together with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, serve to explain the principles of these inventions.
[0020] FIGS. 1A-1C are a depiction of the operation of a hydrant of the prior art;
[0021] FIGS. 2A-2C are a series of figures depicting the use of a flow diverter of the prior art;
[0022] FIG. 3 is a cross section of a venturi of the prior art;
[0023] FIG. 4 is a perspective view of a venturi system employed by the prior art;
[0024] FIG. 5 is a perspective view of one embodiment of the present invention;
[0025] FIG. 6 is a detailed view of the venturi system of the embodiment of FIG. 5 ;
[0026] FIG. 7 is a perspective view similar to that of FIG. 6 wherein the reservoir has been omitted for clarity;
[0027] FIG. 8 is a cross sectional view of a venturi system that employs a bypass tube of one embodiment of the present invention;
[0028] FIG. 9 is a cross sectional view of a bypass valve used in conjunction with the embodiment of FIG. 5 shown in an open position;
[0029] FIG. 10 shows the bypass valve of FIG. 9 in a closed position;
[0030] FIG. 11 is a top perspective view of one embodiment of the present invention showing a bypass button and an electronic reservoir evacuation button;
[0031] FIG. 12 is a graph showing sanitary hydrant comparisons;
[0032] FIG. 13 is a perspective view of a venturi system of another embodiment of the present invention;
[0033] FIG. 14 is a detailed cross sectional view of FIG. 13 showing the check valve in a closed position when the hydrant is on;
[0034] FIG. 15 is a detailed cross sectional view of FIG. 13 showing the check valve in an open position when the hydrant is off;
[0035] FIG. 16 is a cross sectional view showing a hydrant of another embodiment of the present invention;
[0036] FIG. 17 is a detail view of FIG. 16 ;
[0037] FIG. 18 is a detail view of FIG. 17
[0038] FIG. 19 is a cross section of another embodiment of the present invention; and
[0039] FIG. 20 is a table showing a comparison of various hydrant assemblies and the operation cycle of each.
[0040] It should be understood that the drawings are not necessarily to scale, but that relative dimensions nevertheless can be determined thereby. In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.
[0041] To assist in the understanding of one embodiment of the present invention the following list of components and associated numbering found in the drawings is provided herein:
[0000]
#
Component
2
Hydrant
4
Head
5
Handle
6
Standpipe
10
Drain port
14
Frost line
18
Venturi
22
Diverter
26
Vacuum breaker
30
Siphon tube
34
Check valve
36
Outlet
37
Venturi vacuum inlet and drain port
38
Hydrant inlet valve
42
Bypass
46
Bypass button
50
Casing cover
54
Piston
56
Bypass valve
57
Control rod
58
Secondary spring operated piston
59
Bottom surface
60
EFR button
64
LED
68
Screen piston
72
Reservoir
76
Check valve piston
80
Vent
DETAILED DESCRIPTION
[0042] The venturi 18 and related components used in the hydrants of the prior art is shown in FIGS. 3 and 4 and functions when the hydrant issued in conjunction with a vacuum breaker and a diverter. The diverter is needed to allow the venturi to work properly in light of the flow obstructions associated with the vacuum breaker. A typical on/off cycle for this hydrant (see also FIG. 2 ) requires that the user open the hydrant to cause water to exit the diverter 22 and not the vacuum breaker 26 . As the water flows out of the diverter 22 , a vacuum is created that draws water through a siphon tube 30 and check valve 34 , which evacuates the reservoir (not shown). Flowing water through the diverter 22 for about 30 to 45 seconds will generally evacuate the reservoir. Next, as shown in FIG. 2 , the diverter 22 is pulled down to redirect the water out of the vacuum breaker 26 . The vacuum breaker 26 allows the hydrant 2 to be used with an attached hose and/or a spray nozzle as the vacuum breaker 26 will evacuate the head when the hydrant 2 is shut off, thereby making it frost proof. When the water is flowing out of the vacuum breaker 26 the venturi 18 will stop working and the one-way check valve 34 will prevent water from entering the reservoir. Once the hydrant is shut off, the water in the standpipe 6 will drain through a venturi vacuum inlet and drain port 37 that is in fluid communication with the reservoir similar to that disclosed in U.S. Pat. No. 5,246,028 to Vandepas, which is incorporated by reference herein. The check valve 34 is also pressurized when the hydrant is turned off because the shut off valve 38 is located above the check valve 34 .
[0043] A venturi assembly used in other hydrants that employ a pressurized reservoir also provides a vacuum only when water flows through a diverter. A typical on/off cycle for a hydrant that uses this venturi configuration is similar to that described above, the exception being that a check valve that prevents water from entering the reservoir is not used. When the diverter is transitioned so water flows through the vacuum breaker, the backpressure created thereby will cause water to fill and pressurize the reservoir, which prevents water ingress after hydrant shut off. As the reservoir is at least partially filled with water during normal use, the user needs to evacuate the hydrant after shut off by removing any interconnected hose and diverting fluid for about 30 seconds, which will allow the venturi to evacuate the water from the reservoir.
[0044] A hydrant of embodiments of the present invention shown in FIGS. 5-11 which may employ a venturi with an about ⅛″ diameter nozzle. To account for the decrease in mass flow and associated back pressure that affects the functionality of the venturi described above, a bypass 42 is employed. More specifically, the bypass 42 maintains the flow rate out of the hydrant head 4 and allows for water to be expelled from the head 4 at the expected velocity. Fluid bypass is triggered by actuating a button 46 located on the casing cover 50 as shown in FIG. 11 . When the hydrant is turned on the user pushes the bypass button 46 that will in turn move a bypass piston 54 of a bypass valve 56 into the open position as shown in FIG. 9 . This will allow water to bypass the venturi 2 and re-enter the standpipe above the restriction caused by the venturi. The increased flow rate is greater than could be achieved with a venturi alone, even if the diameter of the venturi nozzle was increased.
[0045] While the bypass allows the mass flow rate to increase greatly, it also causes the venturi to stop creating a vacuum that is needed to evacuate the reservoir. Before normal use, the bypass piston 54 is closed as shown in FIG. 10 . Similar to the system described in FIG. 16 below, the venturi 18 and associated bypass 42 are associated with a control rod 57 that is associated with the hydrant handle 5 . Opening of the hydrant transitions the control rod 57 upwardly, which pulls the venturi 18 and associated bypass 42 upwardly and opens the hydrant inlet valve 38 to initiate fluid flow. Conversely, transitioning the hydrant handle 5 to a closed position will move the venturi 18 and associated bypass 42 downwardly such that a secondary spring operated piston 58 of the bypass valve 56 well contact a bottom surface 59 of the reservoir. As the secondary spring piston 58 contacts the bottom surface 59 , the bypass valve 54 moves to a closed position as shown in FIG. 10 . Moving the handle 5 to an open position to initiate fluid flow through the hydrant head will separate the secondary spring operated piston 58 from the bottom surface 59 of the reservoir which allows the bypass piston 54 to move to an open position as shown in FIG. 9 when the bypass button 46 is actuated. When the bypass 42 is in the closed position, water is forced to flow through the venturi causing a vacuum to occur, thereby causing the reservoir to be evacuated each time the hydrant is used. After water flows from the vacuum breaker for a predetermined time, the user will actuate the bypass button 46 which opens the bypass valve 56 to divert fluid around the venturi 2 . The secondary spring operated piston 58 , which is designed to account for tolerances making assembly of the hydrant easier. The secondary spring operated piston 58 also makes sure the hydrant will operate properly if there are any rocks or debris present in the hydrant reservoir.
[0046] The venturi 18 of this embodiment can be operated in a 7′ bury hydrant with a minimum operating pressure of 25 psi. The other major exception is the addition of the aforementioned bypass valve 56 that allows the hydrant to achieve higher flow rates.
[0047] In operation with a hose, initially the hose is attached to the backflow preventer 26 or the bypass button is pushed to that the venturi will not operate correctly and the one way check valve 34 will be pressurized in such a way to prevent flow of fluid from the reservoir. After the hydrant is shut off, the hose is removed from vacuum breaker 26 . Next the hydrant 2 is turned on and water flows through the vacuum breaker 26 for about 30 seconds. When there is no hose attached, and the bypass has not been activated, the venturi 18 will create a vacuum that suctions water from the reservoir 72 and making the hydrant frost proof. Thus when the hydrant is later shut off, the check valve piston will move up and force open the one way check valve 37 to allow water in the hydrant to drain into the reservoir. This operation will also reset the bypass valve 56 into the closed position.
[0048] Some embodiments of the present invention will also be equipped with an Electronic Freeze Recognition (EFR) device as shown in FIG. 11 . The EFR includes a button 60 that allows the user to ascertain if the water has been evacuated from the standpipe 6 properly and if the hydrant is ready for freezing weather. The device uses a circuit board in concert with a dual color LED 64 as shown in FIG. 11 to warn the operator of a potential freezing problem. When the EFR button 60 is pushed and the LED 64 glows red it indicates that the hydrant has not been evacuated properly. This informs the operator that the water in the reservoir is above the frost line, and the hydrant needs to be evacuated by the method described above. A green LED 64 indicates the hydrant has been operated properly and the hydrant is ready for freezing weather.
[0049] Flow rates for hydrants of embodiments of the present invention compare favorably with existing sanitary hydrants on the market, see FIG. 12 . The prior art models are compared with hydrants that use a vacuum breaker and hydrants that use a double check backflow preventer. The venturi and related bypass system will meet ASSE 1057 specifications.
[0050] Another embodiment of the present invention is shown in FIGS. 13-15 that does not employ a bypass. Variations of this embodiment employ an about 0.147 to an about 0.160 diameter nozzle, which allows for a flow rate of 3 gallons per minute at 25 psi and evacuation of the reservoir at 20 psi. As this configuration meets the desired mass flow characteristics, a bypass is not required to obtain the mass flow rate, and therefore this hydrant can be produced at a lower cost. This embodiment also employs a dual-use check valve. The check valve is closed by a spring when the hydrant is turned on as shown in FIG. 14 to prevent water from filling the reservoir. Again, when water is flowing through the double check backflow preventer a suction can still be produced to pull water from the reservoir through this check valve. When the hydrant is turned off, a screen piston 68 moves up when it contacts the bottom surface 59 of the reservoir which forces the check valve 34 into the open position as shown in FIG. 15 . This allows the water in the hydrant to drain into the reservoir, thereby making the hydrant freeze resistant. Other embodiments of the present invention employ a venturi to evacuate a reservoir, but do not need a diverter to operate correctly. More specifically, a venturi is provided that will evacuate a reservoir through a double check backflow preventer.
[0051] FIGS. 16-18 show a hydrant of another embodiment of the present invention that is simpler and more user friendly than sanitary hydrants currently in use. This hydrant is limited to a 5′ bury depth and a minimum working pressure of about 40 psi, which maximizes the venturi flow rate potential, while still being able to evacuate the reservoir as water flows through a double check. A one-way check valve 34 is provided that is forced open when the hydrant is shut off as shown in FIG. 17 .
[0052] In operation, this venturi system operates similar to those described above with respect to FIGS. 5-11 . More specifically, the venturi is interconnected to a movable control rod 57 that is located within the standpipe 6 . The handle 5 of the hydrant is thus ultimately interconnected to the venturi 18 and by way of the control rod 57 . To turn on the hydrant, the user moves the handle 5 to an open position, which pulls the control rod 57 upwardly and opens the inlet valve 38 such that water can enter the venturi 18 . Pulling the venturi upward also removes the check valve 34 upwardly such that the screen piston 68 moves away from the bottom surface 59 of the hydrant 2 . To turn the hydrant off, the handle 5 is moved to a closed position which moves the control rod 57 downwardly to move the venturi 18 downwardly to close the inlet valve 38 . Moving the venturi downwardly also transitions the screen piston 68 which opens the check valve 34 . To allow for evacuation reservoir a vent 80 may be provided on an upper surface of the hydrant.
[0053] Generally, this hydrant functions when a hose is attached to the backflow preventer. When the hose is attached, the venturi will not operate correctly and the pressure acting on the one way check valve 34 will prevent water ingress into the reservoir 72 . After the hydrant is shut off, the hose is removed from vacuum breaker, the hydrant must be turned on so that the water can flow through the double check vacuum preventer for about 15 seconds. That is, when there is no hose attached, the venturi will create a vacuum sufficient enough to suction water from the reservoir 72 , and making the hydrant frost proof. When the hydrant is later shut off, the check valve piston 26 will move up and force the one way check valve to an open position which allows the water in the hydrant to drain into the reservoir 72 .
[0054] FIG. 19 shows yet another hydrant of embodiments of the present invention that is designed specifically for mild climate use (under 2′ bury) and roof hydrants. The outer pipe of the roof hydrant is a smaller 1½ diameter PVC, instead of the 3″ used in some of the embodiments described above. This hydrant uses a venturi without a check valve in concert with a pressurized reservoir, a diverter is not used. The operation is the same as described above with respect to hydrant with a pressurized reservoir, with the evacuation of the reservoir being completed after the user detaches the hose.
[0055] FIG. 20 is a table comparing the embodiments of the present invention, which employ an improved venturi of that employ a bypass system, with hydrants of the prior art manufactured by the Assignee of the instant application. The embodiment shown in FIG. 7 , for example, provides an increased flow rate, has an increased bury depth, and can operate at lower fluid inlet pressures. The evacuation time is discussed over the prior art.
[0056] While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims. Further, the invention(s) described herein is capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. For example, aspects of inventions disclosed in U.S. Pat. Nos. 5,632,303, 5,590,679, 7,100,637, 5,813,428, and 20060196561, all of which are incorporated herein by this reference, which generally concern backflow prevention, may be incorporated into embodiments of the present invention. Aspects of inventions disclosed in U.S. Pat. Nos. 5,701,925 and 5,246,028, all of which are incorporated herein by this reference, which generally concern sanitary hydrants, may be incorporated into embodiments of the present invention. Aspects of inventions disclosed in U.S. Pat. Nos. 6,532,986, 6,805,154, 6,135,359, 6,769,446, 6,830,063, RE39235, 6,206,039, 6,883,534, 6,857,442 and 6,142,172, all of which are incorporated herein by this reference, which generally concern freeze-proof hydrants, may be incorporated into embodiments of the present invention. Aspects of inventions disclosed in U.S. Patent and Published Patent Application Nos. D521113, D470915, 7,234,732, 7,059,937, 6,679,473, 6,431,204, 7,111,875, D482431, 6,631,623, 6,948,518, 6,948,509, 20070044840, 20070044838, 20070039649, 20060254647 and 20060108804, all of which are incorporated herein by this reference, which generally concern general hydrant technology, may be incorporated into embodiments of the present invention.
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A freeze resistant sanitary hydrant is provided that employs a reservoir for storage of fluid under the frost line or in an area not prone to freezing. To evacuate this reservoir, a means for altering pressure is provided that is able to function in hydrant systems that employ a vacuum breaker.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus for processing solid frozen comestibles into a smooth, soft and creamy texture, and relates more specifically to such apparatus that is adapted for continuous operation without causing overheating or undue wear thereto.
2. Description of the Prior Art
Apparatus of the type as generally described herein have been known in the prior art for several decades as shown and disclosed in prior U.S. Pat. No. 2,626,133, "Apparatus for Processing Frozen Comestibles" issued Jan. 20, 1953; U.S. Pat. No. 2,626,132, "Mixing Device for Frozen Comestibles" issued Jan. 20, 1953; and U.S. Pat. No. 3,061,279, "Apparatus for Processing Frozen Comestibles" issued Oct. 30, 1962.
In the above patents, the desirability of and equipment for transforming a hard frozen ice cream product to a product for consumption more closely resembling the soft, smooth, creamy and palatable condition of fresh frozen product was disclosed. Subsequent to such disclosure, apparatus made in accordance with the above patents have been employed in the United States and throughout Canada. However, because of certain deficiencies in the apparatus and process for transforming the frozen comestible, the prior art devices never became successful in the United States.
Recently, improvements have been made in the prior art devices to adapt them to a more marketable form in which the processing of frozen comestible may be accomplished in an economically feasible fashion. As a result, such machines have become highly popular and are used in a wide variety of fast food restaurants and ice cream shops. However, it has been found that during particularly busy periods of use that even the improved machines suffer from the deficiency of overheating and undue wear on their electrical motors. The present invention is designed to overcome this problem and provide a machine that can be used continuously without adverse affect.
SUMMARY OF THE INVENTION
The present invention provides an improved apparatus for converting a solid pre-frozen comestible to a semi-solid form having a soft, smooth and creamy texture, but yet is only slightly less cold than the starting material. To permit such apparatus to operate in a substantially continuous mode, the invention includes a fluid drive means that regulates the operation of the apparatus to prevent overheating or excessive wear of the drive motor.
Preferrably, the apparatus is installed in a decorative, eye appealing cabinet that conceals a vertical structural frame. Upper and lower support members are affixed to the frame in a vertically spaced apart relation with a track means connected there between and a vertically aligned tapered auger rotatably mounted from the upper support member.
A vertically movable saddle means normally rests upon the lower support means and is associated with and guided by the track means upon actuation of a linkage means connected between the structural frame and the saddle means. A frusto-conically shaped hopper for receiving frozen comestible is seated upon the saddle means. The hopper includes a large upper opening and a lower narrow discharge opening and is in axial alignment with said auger so that as the saddle means is elevated through actuation of the linkage means, the hopper is raised to receive the auger in an operative relationship. The outer periphery of the auger is adjacent the interior of the hopper so that as the auger is driven, it advances the comestible in the hopper downwardly toward the lower opening thereof from which it exits in its smooth, soft and creamy texture.
The apparatus includes an electrically driven motor, the drive power of which is transferred to the auger by means of a fluid drive unit and associated drive train to protect the motor from excessive operating conditions when the auger is under a large load. Accordingly, an operator of such apparatus need not be skilled or highly trained to use it properly without causing overheating or excessive wear on the motor.
The invention will appear more clearly from the following detailed description when taking in conjunction with the accompanying drawings, showing by way of example, a preferred embodiment of the inventive idea wherein like numerals refer to like parts throughout.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective front view of a preferred embodiment of the apparatus of the present invention for processing frozen comestibles;
FIG. 2 is a front view of the apparatus of FIG. 1 with the housing of the apparatus removed to expose the internal operating members thereof, and particularly showing an auger below which is located a hopper supported by a vertically movable saddle member;
FIG. 3 is a side view of the apparatus of FIG. 2 particularly showing both a linkage assembly for moving the saddle member and a drive assembly including an electric motor and a fluid driven unit for rotatably driving the auger;
FIG. 4 is a rear view of the apparatus of FIG. 2;
FIG. 5 is an exploded perspective view of certain interior components of the apparatus of FIG. 2 and particularly showing the movable saddle member, the hopper supported thereon, and a filler guide for the hopper; and
FIG. 6 is a perspective partial view of the drive assembly shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and with reference first to FIG. 1, a preferred embodiment of an improved frozen comestible conditioning apparatus 10 of the present invention is shown. As described in prior patents referred to in the Background of the Invention herein, which patents are incorporated herein by reference, the present invention provides a device for preferrably processing solid frozen ice cream or ice milk by subjecting it to mechanical action which plasticized, needed and vigorously remixed the hard frozen product, thus reducing the crystal and cell structure of the material to thereby produce a soft, smooth and creamy texture, but with a temperature only slightly less cold than the starting temperature. Although the invention is described herein with respect to ice cream, it should be understood that the present invention is equally adaptable for use with ice milk, frozen yogurt and other comestibles.
The apparatus 10 preferrably includes an attractive styled housing 11 that serves to enclose all of the working components thereof and yet still provide for ready access to permit supply of frozen ice cream to the interior and receipt of the processed product after conditioning. The specific construction of the housing 11 is not crucial to the present invention. However, it is important that the sidewalls of the housing 11 are free of cracks or crevices in which waste material may lodge. Thus, preferrably, the housing 11 includes an integral three-sided cover member 12 that serves as the sidewalls 13 and rear wall 14 of the housing and is formed of stainless steel.
The front face of the housing 11 is provided by a one piece plate 15 that includes an upper planar section 18 and lower leg member 19, and is connectible to the cover member 12. A plastic panel member 20 fits within the space provided between the legs of the plate 15 and has a hinged door for access to the housing interior. A cap member 25 covers the upper portion of the housing 11, and the bottom of the housing is substantially open. However, the apparatus 10 is designed to sit atop a freezer containing frozen comestible product.
Referring now to FIGS. 2 and 3, the apparatus 10 is shown with the housing 11 and cap member 25 removed to reveal an interior structural frame 29 that serves to support in position the other internal components of the apparatus 10. As disclosed in the prior "279" patent described in the Background of the Invention, the apparatus 10 includes an auger 30 suspended from an upper support arm 31 (FIG. 3) of the frame 29. The auger is powered by a drive assembly 32 mounted on the rear of the structural frame 29. The height of the auger 30 is fixed so it will have no substantial vertical movement as it is rotatably driven by the assembly 32. Thus, it is necessary for the device 10 to include an ice cream hopper that is lifted into position adjacent the auger 30 for processing of the ice cream, as will now be described.
The device 10 includes a pair of vertically aligned, spaced apart rods 35 fixed in place between a upper support member 36 and lower support member 37 respectfully of the frame 29 (See FIG. 3). Referring now to FIG. 5, a saddle member 38 is provided in a guided relation to the rods 35 by means of ears 39 through which the rods 35 loosely extend. The saddle member 38 has a large central opening 42 for receiving a conically shaped hopper 43.
The hopper 43 is adapted for reception into the central opening 42 of the saddle 38 with flanges 44 on the upper periphery of the hopper serving as abutment members for seating on the upper periphery of the saddle member central opening 42. The hopper 43 has a central passageway 43(a) with a large upper opening 43(b) and a small lower opening 43(c) that must be small enough to hold the unprocessed ice cream in the hopper until it is conditioned. A loading funnel 45 has a neck portion 46 adapted to fit in the upper portion of the hopper 43 so that the funnel 45 can serve as a guide member for directing frozen comestibles into the hopper 43.
To elevate the saddle member 38 and its associated hopper components, the device 10 includes a linkage assembly 50 (best shown in FIGS. 3 and 4). The assembly 50 includes an axle member 51 (FIG. 4) that is journaled through the frame 29 and has one end attached to a lever 52 for providing selective actuation of the linkage assembly 50. Fixed to the axle 51 are a pair of link members 53 which move in a clockwise fashion upon forward movement of the lever 52. The opposite ends of the links 53 are pivotally connected to links 54 that interconnect the links 53 with yet another pair of links 55. Upper ends 56 of the links 55 are pivotally connected to two pairs of support struts 58 and 59 whereas lower ends 60 are each connected by a turn buckle 61 into a tapped hole 62 (FIGS. 3 and 5) on each ear 39 of the saddle member 38.
As the link members 53 move in a clockwise fashion about the axle 51 upon forward movement of the lever 52, the link members 54 will move essentially in a vertical fashion to elevate the lower ends 60 of the links 55 and thereby raise the saddle member 38 and its associated hopper member 43 in a vertical direction toward the auger 30. As this upward movement occurs, the drive assembly 32 powering the auger 30 is electrically activated to begin rotation of the auger. As the hopper 43 is moved into a position whereby the flights of the auger 30 are adjacent the conical interior of the sidewall of the passageway 43(a), a processing action of any frozen comestible in the hopper 43 is provided to direct the comestible downward through bottom discharge opening 43(c) of the hopper in a soft, smooth texture into a dish, cone or cup held beneath the lower hopper opening 43(c).
Preferably, the drive assembly 32 includes a prime mover in the form of an electrically driven motor 65 (FIG. 3) mounted in a vertical orientation by a C-shaped bracket 66 bolted to the structural frame 29. The motor 65 has an upwardly directed drive shaft 66a extending into a fluid drive unit 67 of the type that is well known in the art and is preferably a Model FV supplied by Fluid Drive Engineering Co., of Wilmette, Ill. The drive unit 67 has a housing 68 and a hollow shaft 69 that receives and is affixed to the motor drive shaft 66a by a key 70 or the like. The shaft 69 extends into the interior of the housing 68 and is connected to a drive vane (not shown). A complimentary drive vane (not shown) is attached to the interior of the housing 68 and the housing is filled with oil that transmits drive force from the shaft 69 to the housing 68 which is rotatable with respect to the shaft 69. A pulley 71 is formed in the bottom of the housing 68 and is connected to a shank 75 (FIG. 3) of the auger 30 by means of a belt and pulley drive train shown generally at 76. Thus, the fluid drive unit 67 provides an indirect drive linkage between electric motor 65 and the auger 30.
Prior art devices to the present invention did not include an indirect connection between the motor 65 and auger 30, but instead, the motor was directly connected to the auger by means of a belt and pulley drive train. Such prior art devices have proved unsatisfactory during busy periods of operation because excessive stress is placed upon the motor 65 resulting in overloading of the electrical circuit driving the apparatus 10 or premature failure of the motor 65. The reason for this problem with prior art devices is the nature of the frozen comestible that is processed by the apparatus 10.
To provide proper processing, the comestible must be hard frozen and preferably in a disc shaped portion which is dropped into the hopper 43. As the hopper 43 is moved upward to initiate processing, the auger 30 engages the frozen product which resists and actually slows down the rotational motion of the auger 30 until the product is softened and spread out due to the pressure of the auger. This resistive stress on the auger 30 places an excessive load on the motor 65 as it attempts to continue driving the auger 30 and often results in interruptions in operation and premature equipment failure.
By addition of the fluid drive unit 67, the auger 30 is no longer directly connected to the motor 65 so that when the retarding force is exerted on the auger 30, the drive unit 67 isolates such force from the motor 65, which is therefore unaffected thereby. In this way, the rotational speed of the auger 30 is permitted to decrease at the beginning of the processing of the comestible product in the hopper 43. As the retarding force of the product decreases, the auger 30 is automatically increased in speed until it again reaches its normal rotational speed. As can be seen, this action is performed regardless of how the machine is operated so that the apparatus 10 requires little operator experience. Thus, the present invention provides an improved comestible converting apparatus than can be used in substantially continuous operation without fear of overloading the circuit powering the apparatus or burn-out of the motor 65.
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An improved apparatus for pressuring a hard frozen comestible, similar to hardened ice cream, while simultaneously subjecting it to mechanical action to reduce the crystal and cell structure of the material to transform it into a soft, smooth and creamy texture only slightly less cold than its starting temperature. The apparatus includes a hopper for receiving the hard frozen comestible to be treated, an auger positioned above the hopper and automatically actuated by movement of the hopper toward the auger to produce conditioning of the comestible by the auger as the hopper and auger move toward one another into an adjacent relationship. The auger is powered by a drive assembly that includes an electrically driven motor and a fluid drive unit to provide a constant drive force on the auger without undue stress on the drive motor.
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This application is a continuation-in-part of copending Bronstein U.S. patent application Ser. No. 265,406, filed Oct. 26, 1988, which is a continuation-in-part of copending Bronstein U.S. patent application Ser. No. 889,823 filed July 24, 1986 .Iadd.both now abandoned.Iaddend..
FIELD OF THE INVENTION
The invention relates to the use of dioxetanes to detect a substance in a sample.
BACKGROUND OF THE INVENTION
Dioxetanes are compounds having a 4-membered ring in which 2 of the members are adjacent oxygen atoms. Dioxetanes can be thermally or photochemically decomposed to form carbonyl products, e.g., esters, ketones or aldehydes. Release of energy in the form of light (i.e., luminescence) accompanies the decompositions.
SUMMARY OF THE INVENTION
In general, the invention features in a first aspect an improvement in an assay method in which a member of a specific binding pair (i.e., two substances which bind specifically to each other) is detected by means of an optically detectable reaction. The improvement includes the reaction, with an enzyme, a dioxetane having the formula ##STR2## where T is a substituted (i.e., containing one or more C 1 -C 7 alkyl groups or heteroatom groups, e.g., carbonyl groups) or unsubstituted cycloalkyl ring (having between 6 and 12 carbon atoms, inclusive, in the ring) or polycycloalkyl group (having 2 or more fused rings, each ring independently having between 5 and 12 carbon atoms, inclusive), bonded to the 4-membered dioxetane ring by a spiro linkage; Y is a fluorescent chromophore, (i.e., Y is group capable of absorbing energy to form an excited, i.e., higher energy, state, from which it emits light to return to its original energy state); X is hydrogen, a straight or branched chain alkyl group (having between 1 and 7 carbon atoms, inclusive, e.g., methyl), a straight chain or branched heteroalkyl group (having between 1 and 7 carbon atoms, inclusive, e.g., methoxy, hydroxyethyl, or hydroxypropyl), an aryl group (having at least 1 ring, e.g., phenyl), a heteroaryl group (having at least 1 ring, e.g., pyrrolyl or pyrazolyl), a heteroalkyl group (having between 2 and 7 carbon atoms, inclusive, in the ring, e.g., dioxane), an aralkyl group (having at least 1 ring, e.g., benzyl), an alkaryl group (having at least 1 ring, e.g., tolyl), or an enzyme-cleavable group, i.e., a group having a bond which can be cleaved by an enzyme to yield an electron-rich moiety bonded to the dioxetane, e.g., phosphate, where a phosphorus-oxygen bond can be cleaved by an enzyme, e.g., acid phosphatase or alkaline phosphatase, to yield a negatively charged oxygen bonded to the dioxetane; and Z is hydrogen, hydroxyl, or an enzyme-cleavable group (as defined above), 10 provided that at least one of X or Z must be an enzyme-cleavable group, so that the enzyme cleaves the enzyme-cleavable group to form a negatively charged substituent (e.g., an oxygen anion) bonded to the dioxetane, the negatively charged substituent causing the dioxetane to decompose to form a luminescent substance (i.e., a substance that emits energy in the form of light) that includes group Y. The luminescent substance is detected as an indication of the presence of the first substance. By measuring the intensity of luminescence, the concentration of the first substance can be determined.
In preferred embodiments, one or more of groups T, X, or Y further include a solubilizing substituent, e.g., carboxylic acid, sulfonic acid, or quaternary amino salt; group T of the dioxetane is a polycycloalkyl group, preferably adamantyl; the enzyme-cleavable group includes phosphate; and the enzyme includes phosphatase.
The invention also features a kit for detecting a first substance in a sample.
In a second aspect, the invention features a method of detecting an enzyme in a sample. The method involves contacting the sample with the above-described dioxetane in which group Z is capable of being cleaved by the enzyme being detected. The enzyme cleaves group Z to form a negatively charged substituent (e.g., an oxygen anion) bonded to the dioxetane. This substituent destabilizes the dioxetane, thereby causing the dioxetane to decompose to form a luminescent substance that includes group Y of the dioxetane. The luminescent substance is detected as an indication of the presence of the enzyme. By measuring the intensity of luminescence, the concentration of the enzyme can also be determined.
The invention provides a simple, very sensitive method for detecting substances in samples, e.g., biological samples, and is particularly useful for substances present in low concentrations. Because dioxetane decomposition serves as the excitation energy source for chromophore Y, an external excitation energy source, e.g., light, is not necessary. In addition, because the dioxetane molecules are already in the proper oxidation state for decomposition, it is not necessary to add external oxidants, e.g., H 2 O 2 or O 2 . Enzyme-activated decomposition allows for high sensitivity because one enzyme molecule can cause many dioxetane molecules to luminesce, thus creating an amplification effect. Moreover, the wavelength (or energy) of emission and the quantum yields of luminescence can be varied according to the choice of the Y substituent of the dioxetane (as used herein, "quantum yield" refers to the number of photons emitted from the luminescent product per number of moles of dioxetane decomposed). In addition, through appropriate modifications of the T, X, and Y groups of the dioxetane, the solubility of the dioxetane and the kinetics of dioxetane decomposition can be varied. The dioxetanes can also be attached to a variety of molecules, e.g., proteins or haptens, or immobilization substrates, e.g., polymer membranes, or included as a side group in a homopolymer or copolymer.
Other features and advantages of the invention will be apparent from the following description of the preferred embodiments thereof, and from the claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 compares a solid state quantitative colorimetric assay for human chorionic gonadotropin (hCG) using p-nitrophenyl phosphate (PNPP) as chromogen with the quantitative chemiluminescence assay of the invention using 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl-1,2-dioxetane, disodium salt (AMPPD) as the lumogen.
FIG. 2 shows the results of the solid state immunoassay for hCG of the invention using AMPPD as the lumogen and using film exposure for detection of the hCG.
FIG. 3 is a standard curve for the quantitative estimation of the concentration of the enzyme alkaline phosphatase by the AMPPD chemiluminescence assay of the invention.
FIG. 4 compares the quantitative estimation of the concentration of the enzyme alkaline phosphatase by the AMPPD chemiluminescence assay of the invention in the presence and absence of bovine serum albumin (BSA), fluorescein (BSA-Fluor.) poly[vinylbenzyl(benzyldimethyl ammonium chloride)] (BDMQ), and BDMQ-Fluor.
FIG. 5 shows the results of a Herpes Simplex Virus I (HSVI) DNA probe assay using a specific alkaline phosphatase-labeled ADNA probe in conjunction with the AMPPD chemiluminescence assay of the invention.
FIG. 6 shows the time course of the AMPPD chemiluminescence method of the invention applied to the hybridization-based detection of hepatitis B core antigen plasmid DNA (HBV c ) with an alkaline phosphatase-DNA probe conjugate, using a film detection technique.
FIG. 7 shows the time course of the colorimetric detection of Hepatitis B core antigen plasmid DNA with an alkaline phosphatase-DNA probe conjugate using nitroblue tetrazolium (NBT)/5-bromo-4-chloro-3-indolyl phosphate (BCIP) as substrates.
FIG. 8 shows the quantitative application of the assay of FIG. 6, wherein the film images were quantified by measuring reflection densities.
FIG. 9 compares a solid state ELISA method for alpha feto protein (AFP) using PNPP as a colorimetric substrate and the AMPPD chemiluminescence method of the invention for the quantitative estimation of AFP, wherein alkaline phosphatase is covalently linked to anti-AFP antibody.
FIG. 10 shows a solid state monoclonal antibody ELISA for thyroid stimulating hormone (TSH) using the AMPPD chemiluminescence method of the invention wherein monoclonal anti-β-TSH antibody conjugated to alkaline phosphatase was used as the detection antibody.
FIG. 11 represents the assay of FIG. 10 carried out both in the absence and presence of BSA.
FIG. 12 shows the application of a solid state ELISA to the estimation of carcinoembryonic antigen (CEA), wherein α-CEA antibody-alkaline phosphatase was the detection antibody and the AMPPD chemiluminescence method of the invention was used to quantify the CEA.
FIG. 13 is a diagram of the device used for the solid state immunoassay for human luteinizing hormone (hLH).
FIG. 14 shows the assay images on film for a solid state immunoassay for hLH wherein monoclonal anti-hLH antibody-alkaline phosphatase is the detection antibody and the AMPPD chemiluminescence assay of the invention was used to detect the hLH antigen.
FIG. 15 shows a standard curve obtained for hLH wherein the film images obtained by the method of FIG. 14 were quantified by reflection density determinations at each concentration of hLH.
FIG. 16 shows a plot of chemiluminescence as a function of α-galactosidase concentration in the chemiluminescence assay of the invention wherein the substrate for the enzyme is 3-(2'-spiroadamantane)-4-methoxy-4-(3"-β-D-galactopyranosyl)phenyl-1,2-dioxetane (AMPGD).
FIG. 17 shows the pH dependence of β-galactosidase-activated chemiluminescence from AMPGD.
FIG. 18 shows the production of light by β-galactosidase decomposition of AMPGD wherein the light intensity was measured after enzyme incubation at a pH of 7.3 and adjusting the pH to 12 with alkali.
FIG. 19 shows a two-hour lumiautogram on X-ray film (A) and Polaroid instant black and white film (B) of DNA fragments visualized by AMPPD chemiluminescence following electrophoretic separation of DNA fragments produced by the Sanger sequencing protocol.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The structure, synthesis, and use of preferred embodiments of the invention will now be described.
Structure
The invention employs dioxetanes having the structure recited in the Summary of the Invention above. The purpose of group T is to stabilize the dioxetane, i.e., to prevent the dioxetane from decomposing before the enzyme-cleavable group Z is cleaved. Large, bulky, sterically hindered molecules, e.g., fused polycyclic molecules, are the most effective stabilizers. In addition, T preferably contains only C--C and C--H single bonds. The most preferred molecule is an adamantyl group consisting of 3 fused cyclohexyl rings. The adamantyl group is bonded to the 4-membered ring portion of the dioxetane through a spiro linkage.
Group Y is a fluorescent chromophore bonded to enzyme-cleavable group Z. Y becomes luminescent when an enzyme cleaves group Z, thereby creating an electron-rich moiety which destabilizes the dioxetane, causing the dioxetane to decompose. Decomposition produces two individual carbonyl compounds, one of which contains group T, and the other of which contains groups X, Y, and Z; the energy released from dioxetane decomposition causes the Y groups of the latter carbonyl compound to luminesce (if group X is hydrogen, an aldehyde is produced).
The excited state energy of chromophore Y (i.e., the energy chromophore Y must possess in order to emit light) is preferably less than the excited state energy of the ketone containing group T in order to confine luminescence to group Y. For example, when Y is adamantyl, the excited state energy of chromophore Y is preferably less than the excited state energy of spiroadamantane.
Any chromophore Y can be used according to the invention. In general, it is desirable to use a chromophore which maximizes the quantum yield in order to increase sensitivity.
Examples of suitable chromophores include the following:
(1) anthracene and anthracene derivatives, e.g., 9,10-diphenylanthracene, 9-methylanthracene, 9-anthracene carboxaldehyde, anthryl alcohols and 9-phenylanthracene;
(2) rhodamine and rhodamine derivatives, e.g., rhodols, tetramethyl rhodamine, tetraethyl rhodamine, diphenyldimethyl rhodamine, diphenyldiethyl rhodamine, and dinaphthyl rhodamine;
(3) fluorescein and fluorescein derivatives, e.g., 5-iodoacetamido fluorescein. 6-iodoacetamido fluorescein, and fluorescein-5-maleimide;
(4) eosin and eosin derivatives, e.g., hydroxy eosins, eosin-5-iodoacetamide, and eosin-5-maleimide;
(5) coumarin and coumarin derivatives, e.g., 7-dialkylamino-4-methylcoumarin, 4-bromomethyl-7-methoxycoumarin, and 4-bromomethyl-7-hydroxycoumarin;
(6) erythrosin and erythrosin derivatives, e.g., hydroxy erythrosins, erythrosin-5-iodoacetamide and erythrosin-5-maleimide;
(7) aciridine and aciridine derivatives, e.g., hydroxy aciridines and 9-methyl aciridine;
(8) pyrene and pyrene derivatives, e.g., N-(1-pyrene) iodoacetamide, hydroxy pyrenes, and 1-pyrenemethyl iodoacetate;
(9) stilbene and stilbene derivatives, e.g., 6,6'-dibromostilbene and hydroxy stilbenes;
(10) naphthalene and naphthalene derivatives, e.g., 5-dimethylaminonaphthalene-1-sulfonic acid and hydroxy naphthalene;
(11) nitrobenzoxadiazoles and nitrobenzoxadiazole derivatives, e.g., hydroxy nitrobenzoxadiazoles, 4-chloro-7-nitrobenz-2-oxa-1,3-diazole, 2-(7-nitrobenz-2-oxa-1,3-diazol-4-yl-amino)hexanoic acid;
(12) quinoline and quinoline derivatives, e.g., 6-hydroxyquinoline and 6.aminoquinoline;
(13) acridine and acridine derivatives, e.g., N-methylacridine and N-phenylacridine;
(14) acidoacridine and acidoacridine derivatives, e.g., 9-methylacidoacridine and hydroxy-9-methylacidoacridine;
(15) carbazole and carbazole derivatives, e.g., N-methylcarbazole and hydroxy-N-methylcarbazole;
(16) fluorescent cyanines, e.g., DCM (a laser dye), hydroxy cyanines, 1,6-diphenyl-1,3,5-hexatriene, 1-(4-dimethyl aminophenyl)-6-phenylhexatriene, and the corresponding 1,3-butadienes.
(17) carbocyanine and carbocyanine derivatives, e.g., phenylcarbocyanine and hydroxy carbocyanines;
(18) pyridinium salts, e.g., 4(4-dialkyldiaminostyryl) N-methyl pyridinium iodate and hydroxy-substituted pyridinium salts;
(19) oxonols; and
(20) resorofins and hydroxy resorofins.
The most preferred chromophores are hydroxy derivatives of anthracene or naphthalene; the hydroxy group facilitates bonding to group Z.
Group Z is bonded to chromophore Y through an enzyme-cleavable bond. Contact with the appropriate enzyme cleaves the enzyme-cleavable bond, yielding an electron-rich moiety bonded to a chromophore Y; this moiety initiates the decomposition of the dioxetane into two individual carbonyl compounds e.g., into a ketone or an ester and an aldehyde if group X is hyrdogen. Examples of electron-rich moieties include oxygen, sulfur, and amine or amino anions. The most preferred moiety is an oxygen anion. Examples of suitable Z groups, and the enzymes specific to these groups are given below in Table 1; an arrow denotes the enzyme-cleavable bond. The most preferred group is a phosphate ester, which is cleaved by alkaline or acid phosphatase enzymes.
TABLE 1__________________________________________________________________________Group Z Enzyme__________________________________________________________________________(1) ##STR3## alkaline and acid phosphatases phosphate ester(2) ##STR4## esterases acetate ester(3) ##STR5## decarboxylases carboxyl(4) ##STR6## phospholipase D 3-phospho-1,2-diacyl glycerides(5) ##STR7## β-xylosidase β-D-xyloside(6) ##STR8## β-D-fucosidase β-D-fucoside(7) ##STR9## thioglucosidase 1-thio-D-glucoside(8) ##STR10## β-D-galactosidase β-D-galactoside(9) ##STR11## α-D-galactosidase α-D-galactoside(10) ##STR12## α-D-glucosidase α-D-glucoside(11) ##STR13## β-D-glucosidase β-D-glucoside(12) ##STR14## α-D-mannosidase α-D-mannoside(13) ##STR15## β-D-mannosidase β-D-mannoside(14) ##STR16## β-D-fructofuranosidase β-D-fructofuranoside(15) ##STR17## β-D-glucosiduronase β-D-glucosiduronate(16) ##STR18## trypsin p-toluenesulfonyl-L-arginine ester(17) ##STR19## trypsin p-toluenesulfonyl-L-arginine amide__________________________________________________________________________
Suitable X groups are described in the Summary of the Invention, above. Preferably, X contains one or more solubilizing substituents, i.e., substituents which enhance the solubility of the dioxetane in aqueous solution Examples of solubilizing substituents include carboxylic acids, e.g., acetic acid; sulfonic acids, e.g., methanesulfonic acid; and quaternary amino salts, e.g., ammonium bromide; the most preferred solubilizing substituent is methane-or ethanesulfonic acid.
Preferably, the enzyme which cleaves group Z is covalently bonded to a substance having a specific affinity for the substance being detected. Examples of specific affinity substances include antibodies, e.g., anti-hCG; antigens, e.g., hCG, where the substance being detected is an antibody, e.g., anti-hCG; a probe capable of binding to all or a portion of a nucleic acid, e.g., DNA or RNA, being detected; or an enzyme capable of cleaving the Y--Z bond. Bonding is preferably through an amide bond.
Synthesis
In general, the dioxetanes of the invention are synthesized in two steps. The first step involves synthesizing an appropriately substituted olefin having the formula ##STR20## wherein T, X, Y, and Z are as described above. These olefins are preferably synthesized using the Wittig reaction, in which a ketone containing the T group is reacted with a phosphorus ylide (preferably based on triphenylphosphine) containing the X, Y, and Z groups, as follows: ##STR21## The reaction is preferably carried out below about -70° C. in an ethereal solvent, e.g., tetrahydrofuran (THF).
The phosphorus ylide is prepared by reacting triphenyl phosphine with a halogenated compound containing the X, Y, and Z groups in the presence of base; examples of preferred bases include n-butyllithium, sodium amide, sodium hydride, and sodium alkoxide; the most preferred base is n-butyllithium. The reaction sequence is as follows: ##STR22## where Q is a halogen, e.g., Cl, Br, or I. The preferred halogen is Br. The reaction is preferably carried out below about -70° C. in THF.
The olefin where T is adamantyl (Ad), X is methoxy (OCH 1 ), Y is anthracene (An), and Z is phosphate (PO 4 ) can be synthesized as follows. ##STR23## is phosphorylated by treating it with the product of phosphorus acid reacted in the presence of HgCl 2 with N-methylimidazole; the net result is to replace the hydroxyl group of An with a phosphate group. The phosphorylated product is then reacted with triphenylphospine below about -70° C. in THF to form the phosphorus ylide having the formula ##STR24## The reaction is conducted in a dry argon atmosphere, Spiroadamantanone (Ad=O) is then added to the solution containing the ylide, while maintaining the temperature below about -70° C., to form the olefin having the formula ##STR25## The olefin is then purified using conventional chromatography methods.
The second step in the synthesis of the dioxetanes involves converting the olefin described above to the dioxetane. Preferably, the conversion is effected photochemically by treating by olefin with singlet oxygen ( 1 O 2 ) in the presence of light. 1 O 2 adds across the double bond to form the dioxetane as follows: ##STR26## The reaction is preferably carried out below about -70° C. in a halogenated solvent, e.g., methylene chloride. 1 O 2 is generated 10 using a photosensitizer. Examples of photosensitizers include polymer-bound Rose Bengal (commercially known as Sensitox I and available from Hydron Laboratories, New Brunswick, N.J.), which is preferred, and methylene blue (a well-known dye and pH indicator).
The synthesis of the dioxetane having the formula ##STR27## follows.
The olefin having the formula ##STR28## is dissolved in methylene chloride, and the solution is placed in a 2-cm 2 pyrex tube equipped with a glass paddle; the paddle is driven from above by an attached, glass enclosed, bar magnet. The solution is cooled to below about -70° C. and 1 g of polymer-bound Rose Bengal is added with stirring. Oxygen is then passed over the surface of the agitated solution while the reaction tube is exposed to light from a 500 W tungsten-halogen lamp (GE Q500 Cl) equipped with a UV-cut off filter (Corning 3060: transmission at 365 nm=0.5%). Thin layer chromatography (tlc) is used to monitor the disappearance of the olefin and the concurrent appearance of the dioxetane. After the reaction is complete (as indicated by tlc), the solvent is removed and the dioxetane is isolated.
Use
A wide variety of assays exist which use visually detectable means to determine the presence or concentration of a particular substance in a sample. The above-described dioxetanes can be used in any of these assays. Examples of such assays include immunoassays to detect antibodies or antigens, e.g., α or β-hCG; enzyme assays; chemical assays to detect, e.g., potassium or sodium ions; and nucleic acid assays to detect, e.g., viruses (e.g., HTLV III or cytomegalovirus, or bacteria (e.g., E. coli)).
When the detectable substance is an antibody, antigen, or nucleic acid, the enzyme capable of cleaving group Z of the dioxetane is preferably bonded to a substance having a specific affinity for the detectable substance (i.e., a substance that binds specifically to the detectable substance), e.g, an antigen, antibody, or nucleic acid probe, respectively. Conventional methods, e.g., carbodiimide coupling, are used to bond the enzyme to the specific affinity substance; bonding is preferably through an amide linkage.
In general, assays are performed as follows. A sample suspected of containing a detectable substance is contacted with a buffered solution containing an enzyme bonded to a substance having a specific affinity for the detectable substance. The resulting solution is incubated to allow the detectable substance to bind to the specific affinity portion of the specific affinity-enzyme compound. Excess specific affinity-enzyme compound is then washed away, and a dioxetane having a group Z that is cleavable by the enzyme portion of the specific affinity-enzyme compound is added. The enzyme cleaves group Z, causing the dioxetane to decompose into two carbonyl compounds (e.g., an ester or ketone when group X is other than hydrogen and an aldehyde when group X is hydrogen); chromophore Y bonded to one of the ketones is thus excited and luminesces. Luminescence is detected using e.g., a cuvette or camera luminometer, as an indication of the presence of the detectable substance in the sample. Luminescence intensity is measured to determine the concentration of the substance.
When the detectable substance is an enzyme, a specific affinity substance is not necessary. Instead, a dioxetane having a Z group that is cleavable by the enzyme being detected is used. Therefore, an assay for the enzyme involves adding the dioxetane to the enzyme-containing sample, and detecting the resulting luminescence as an indication of the presence and the concentration of the enzyme.
Examples of specific assays follow.
A. Assay for Human IgG
A 96-well microtiter plate is coated with sheep anti-human IgG (F(ab) 2 fragment specific). A serum sample containing human IgG is then added to the wells, and the wells are incubated for 1 hour at room temperature.
Following the incubation period, the serum sample is removed from the wells, and the wells are washed four times with an aqueous buffer solution containing 0.15 M NaCl, 0.01 M phosphate, and 0.1% bovine serum albumin (pH 7.4).
Alkaline phosphatase bonded to anti-human IgG is added to each well, and the wells are incubated for 1 hr. The wells are then washed four times with the above buffer solution, and a buffer solution of a phosphate-containing dioxetane is added. The resulting luminescence caused by enzymatic degradation of the dioxetane is detected in a luminometer, or with photographic film in a camera luminometer.
B. Assay for hCG
Rabbit anti-α-hCG is adsorbed onto a nylon-mesh membrane. A sample solution containing hCG, e.g., urine from a pregnant woman, is blotted through the membrane, after which the membrane is washed with 1 ml of a buffer solution containing 0.15 M NaCl, 0.01 M phosphate, and 0.1% bovine serum albumin (pH 7.4).
Alkaline phosphatase-labelled anti-β-hCG is added to the membrane, and the membrane is washed again with 2 ml of the above buffer solution. The membrane is then placed in the cuvette of a luminometer or into a camera luminometer, and contacted with a phosphate-containing dioxetane. The luminescence resulting from enzymatic degradation of the dioxetane is then detected.
C. Assay for Serum Alkaline Phosphatase
2.7 ml of an aqueous buffer solution containing 0.8 M 2-methyl-2-aminopropanol is placed in a 12×75 mm pyrex test tube, and 0.1 ml of a serum sample containing alkaline phosphatase added. The solution is then equilibrated to 30° C. 0.2 ml of a phosphate-containing dioxetane is added, and the test tube immediately placed in a luminometer to record the resulting luminescence. The level of light emission will be proportional to the rate of alkaline phosphatase activity.
D. Nucleic Acid Hybridization Assay
A sample of cerebrospinal fluid (CSF) suspected of containing cytomegalovirus is collected and placed on a nitrocellulose membrane. The sample is then chemically treated with urea or guanidinium isothiocyanate to break the cell walls and to degrade all cellular components except the viral DNA. The strands of the viral DNA thus produced are separated and attached to the nitrocellulose filter. A DNA probe specific to the viral DNA and labelled with alkaline phosphatase is then applied to the filter; the probe hybridizes with the complementary viral DNA strands. After hybridization, the filter is washed with an aqueous buffer solution containing 0.2 M NaCl and 0.1 mM Tris-HCl (pH=8.10) to remove excess probe molecules. A phosphate-containing dioxetane is added and the resulting luminescence from the enzymatic degradation of the dioxetane is measured in a luminometer or detected with photographic film.
E. Assay for Galactosidase
In the assays described above and in the Examples to follow dioxetanes containing α- or β- galactosidase-cleavable α-D- or β-D-galactopyranoside groups, respectively, can be added, and the luminescence resulting from the enzymatic cleavage of the sugar moiety from the chromophore measured in a luminometer or detected with photographic film.
F. Electrophoresis
Electrophoresis allows one to separate complex mixtures of proteins and nucleic acids according to their molecular size and structure on gel supports in an electrical field. This technique is also applicable to separate fragments of protein after proteolysis, or fragments of nucleic acids after scission by restriction endonucleases (as in DNA sequencing). After electrophoretic resolution of species in the gel, or after transfer of the separated species from a gel to a membrane, the bonds are probed with an enzyme bound to a ligand. For example, peptide fragments are probed with an antibody covalently linked to alkaline phosphatase. For another example, in DNA sequencing alkaline phosphatase--avidin binds to a biotinylated nucleotide base. Thereafter, AMPPD is added to the gel or membrane filter. After short incubation, light is emitted as the result of enzymatic activation of the dioxetane to form the emitting species. The luminescence is detected by either X-ray or instant photographic film, or scanned by a luminometer. Multichannel analysis further improves the process by allowing one to probe for more than one fragment simultaneously. G. In solid state assays, it is desireable to block nonspecific binding to the matrix by pretreatment of nonspecific binding sites with nonspecific proteins such as bovine serum albumin (BSA) or gelatin. Applicant has determined that some commercial preparations of BSA contain small amounts of phosphatase activity that will produce undesirable background chemiluminescence from AMPPD. Applicant has discovered that certain water-soluble synthetic macromolecular substances are efficient blockers of nonspecific binding in solid state assays using dioxetanes. Preferred among such substances are water-soluble polymeric quaternary ammonium salts such as poly(vinylbenzyltrimethyl-ammonium chloride) (TMQ) or poly[vinylbenzyl(benzyldimethyl-ammonium chloride)] (BDMQ).
H. Assay for Nucleotidase
An assay for the enzyme ATPase is performed in two steps. In the first step, the enzyme is reacted at its optimal pH (typically pH 7.4) with a substrate comprising ATP covalently linked via a terminal phosphoester bond to a chromophore-substituted 1,2-dioxetane to produce a phosphoryl-chromophore-substituted 1,2-dioxetane. In the second step, the product of the first step is decomposed by the addition of acid to bring the pH to below 6, preferably to pH 2-4, and the resulting light measured in a luminometer or detected with chromatographic film. In a similar two-step procedure, ADPase is assayed using as the substrate an ADP derivative of a chromophore-substituted 1,2-dioxetane, and 5'-nucleotidase assayed using as the substrate an adenylic acid derivative of a chromophore-substituted 1,2-dioxetane. The second step can also be carried out by adding the enzyme alkaline phosphatase to decompose the phosphoryl-chromophore-substituted 1,2-dioxetane.
I. Nucleic Acid Sequencing
DNA or RNA fragments, produced in sequencing protocols, can be detected after electrophoretic separation using the chemiluminescent 1,2-dioxetanes of this invention.
DNA sequencing can be performed by a dideoxy chain termination method [Sanger, F., et al., Proc. Nat. Acad. Sci. (USA). 74:5463 (1977)]. Briefly, for each of the four sequencing reactions, single-stranded template DNA is mixed with dideoxynucleotides and biotinylated primer strand DNA. After annealing, Klenow enzyme ant deoxyadenosine triphosphate are incubated with each of the four sequencing reaction mixtures, then chase deoxynucleotide triphosphate is added and the incubation continued.
Subsequently, DNA fragments in reaction mixtures are separated by polyacrylamide gel electrophoresis (PAGE). The fragments are transferred to a membrane, preferably a nylon membrane, and the fragments cross-linked to the membrane by exposure to UV light, preferably of short wave length.
After blocking non-specific binding sites with a polymer, e.g., heparin, casein or serum albumin, the DNA fragments on the membrane are contacted with avidin or streptavidin covalently linked to an enzyme specific for the enzyme-cleavable group of the 1,2-dioxetane substrates of this invention. As avidin or streptavidin bind avidly to biotin, biotinylated DNA fragments will now be tagged with an enzyme. For example when the chemiluminescent substrate is 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl-1,2-dioxetane salt (AMPPD), avidin or streptavidin will be conjugated to a phosphatase. Similarly, when the chemiluminescent substrate is 3-(2'-spiroadamantane)-4-methoxy-4-(3"-β-D-galactopyranosyl)phenyl-1,2-dioxetane (AMPGD), avidin or streptavidin are conjugated with β-galactosidase.
Following generation of luminescence by contacting the complex of DNA fragment-biotin-avidin (or streptavidin)-enzyme with the appropriate 1,2-dioxetane at alkaline pH values, e.g., above about pH 8.5, DNA fragments are visualized on lightsensitive film, e.g, X-ray or instant film, or in a photoelectric luminometer instrument.
The detection method outlined above can also be applied to the genomic DNA sequencing protocol of Church et al. [Church, G.M., et al., Proc. Nat. Acad. Sci. (USA), 81:1991 (1984)]. After transferring chemically cleaved and electrophoretically separated DNA [Maxam, A.M. et al., Proc. Nat. Acad. Sci. (USA), 74:560 (1977)] to a membrane, preferably a nylon membrane, and cross-linking the ladders to the membrane by UV light, specific DNA sequences may be detected by sequential addition of: biotinylated oligonucleotides as hybridization probes; avidin or streptavidin covalently linked to an enzyme specific for an enzyme-cleavable chemiluminescent 1,2-dioxetane of this invention; and, the appropriate 1,2-dioxetane. Images of sequence ladders (produced by PAGE) may be obtained as described above.
Serial reprobing of sequence ladders can be accomplished by first stripping the hybridized probe and chemiluminescent material from a membrane by contacting the membrane with a heated solution of a detergent, e.g., from about 0.5 to about 5% sodium dodecylsulfate (SDS) in water at from about 80° C. to about 90° C., cooling to from about 50° C. to about 70° C., hybridizing the now-naked DNA fragments with another biotinylated oligonucleotide probe to generate a different sequence, then generating an imaging chemiluminescence as described above.
Similar visualization methods can be applied to RNA fragments generated by RNA sequencing methods.
Other embodiments are within the following claims.
For example, the enzyme-cleavable group Z can be bonded to group X of the dioxetane, instead of group Y. The specific affinity substance can be bonded to the dioxetane through groups X, Y, or T (preferably group X), instead of the enzyme. In this case, the group to which the specific affinity substance is bonded is provided with, e.g., a carboxylic acid, amino, or maleimide substituent to facilitate bonding.
Groups X, Y, or T of the dioxetane can be bonded to a polymerizable group, e.g., a vinyl group, which can be polymerized to form a homopolymer or copolymer.
Groups X, Y, or T of the dioxetane can be bonded to, e.g., membranes, films, beads, or polymers for use in immuno- or nucleic acid assays. The groups are provided with, e.g., carboxylic acid, amino, or maleimide substituents to facilitate bonding.
Groups X, Y, or T of the dioxetane can contain substituents which enhance the kinetics of the dioxetane enzymatic degradation, e.g., electron-rich moieties (e.g., methoxy).
Groups Y and T of the dioxetane, as well as group X, can contain solubilizing substituents.
Appropriately substituted dioxetanes can be synthesized chemically, as well as photochemically. For example, the olefin prepared from the Wittig reaction can be epoxidized using a peracid, e.g., p-nitroperbenzoic acid. The epoxidized olefin can then be converted to the dioxetane by treatment with an ammonium salt, e.g., tetramethylammonium hydroxide.
Another example of a chemical synthesis involves converting the olefin prepared from the Wittig reaction to a 1,2-hydroperoxide by reacting the olefin with H 2 O 2 and dibromantin (1,3-dibromo-5,5-dimethyl hydantoin). Treatment of the 1,2-bromohydroperoxide with base, e.g., an alkali or alkaline earth methalhydroxide such as sodium hydroxide or a silver salt, e.g., silver bromide, forms the dioxetane.
Olefin precursors for the dioxetane can be synthesized by reacting a ketone with a ester in the presence of TiCl and lithium aluminum hydride (LAH). For example, to synthesize an olefin where T is adamantyl (Ad), X is methoxy (OCH 3 ), Y is anthracene (An), and Z is phosphate (PO 4 ), the following reaction sequence is used: ##STR29##
To phosphorylate chromophore Y, e.g., anthracene, a hydroxyl derivative of the chromophore, e.g., hydroxy anthracene, can be reacted with a cyclic acyl phosphate having the following formula: ##STR30## The reaction product is then hydrolyzed with water to yield the phosphorylated chromophore. The cyclic acyl phosphate is prepared by reacting 2,2,2-trimethoxy-4,5-dimethyl-1,3-dioxaphospholene with phosgene at 0° C., following by heating at 120° C. for 2 hr.
The following examples are intended to illustrate the invention in detail, but they are in no way to be taken as limiting, and the present invention is intended to encompass modifications and variations of these examples within the framework of their contents and the claims.
EXAMPLE 1
Bead Format Human Chorionic Gonadotrophin (hCG) Assay, (Serum or Urine)
In the following, an hCG assay method is described in which 3-(2'spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl-1,2 dioxetane, disodium salt (AMPPD, synthesized as described above), was used as a substrate of aIkaline phosphatase. For comparison, a colorimetric assay was conducted using p-nitrophenylphosphoric acid (PNPP) as a substrate.
1. Placed one bead which was previously coated with anti-hCG in each tube (12×75 mm) after blotting excess buffer from bead.
2. Added 100 μl of anti-hCG antibody-alkaline phosphatase conjugate to each tube.
3. To each tube added 100 μof sample. Separate tubes were prepared for each of the following:
(a) Control Zero Sample, (male serum or urine)
(b) 25 mIU/ml hCG standard (serum or urine)
(c) 200 mIU/ml hCG standard (serum or urine)
(d) Patient sample (serum or urine)
4. After mixing, the tubes were covered and incubated for 90 minutes at 37° C.
5. The reaction solution containing the conjugate and sample were aspirated to waste.
6. The beads were washed 3 times with 2.0 ml of phosphate buffered saline, pH 7.4, containing 0.1% Tween 20.
______________________________________For Colorimetric Assay Chemiluminescence______________________________________ 7. N/A 7. Washed once with 0.05 M carbonate, 1 mM MgCl.sub.2 pH 9.5. 8. Added 200 μl 1 mg/ml 8. Added 250 μl of 0.4 mM p-nitrophenyl-phosphate AMPPD in 0.05 M carbonate, (PNPP) in 0.1 M glycine, 1 mM MgCl.sub.2, pH 9.5 1 mM MgCl.sub.2, pH 10.4 9. Incubated for 30 minutes 9. Incubated for 20 minutes at room temperature at 30° C.10. Added 11.5 ml of 0.1 M 10. N/A glycine, 10 mM of EDTA, pH 9.5, to stop color development11. Read absorbance at 405 11. Read 10 sec. integral of nm in spectrophotometer luminescence from each tube in Turner 20E Luminometer______________________________________
12. Plotted both sets of data as the signal at each concentration of hCG divided by the signal at zero hCG vs. concentration of hCG. Typical data are plotted in FIG. 1, wherein PNPP represents the colorimetric assay and AMPPD the chemiluminescence assay. The chemiluminescence assay was over ten times as sensitive as the colorimetric assay.
EXAMPLE 2
Tandem Icon II hCG Assay (By Film Exposure)
Used a commercial Tandem ICON II assay kit (Hybritech, Inc.). Buffers and antibodies used were included in the kit and AMPPD was used as a substrate of alkaline phosphatase. METHOD
1. Prepared hCG standards at 0, 5, 10, 50 mIU/ml diluted in control negative (male) urine for use as test samples.
2. Added 5 drops of the sample to the center of an ICON membrane device.
3. Added 3 drops of enzyme antibody conjugate to the center of each device.
4. Incubated for 1 minute.
5. Added 2 ml of Hybritech ICON wash solution to the device. Allowed to drain.
6. Added 500 μl of 0.1% BSA in 0.1 M Tris buffer, 1 mM MgCl 2 , pH 9.8. Allowed to drain.
7. Added 200 μl of 50 μg/ml AMPPD in 0.1% BSA, 0.1 M Tris buffer, pH 9.8, 1 mM MgCl 2 .
8. Transferred ICON membrane to a piece of Mylar polyester film and inserted into a black box to expose film. (Polaroid Type 612).
9. Exposed film for 30 seconds. The results of a typical assay are shown in FIG. 2. Intense chemiluminescence from positive samples occurred within a 30-second reaction time.
EXAMPLE 3
Alkaline Phosphatase Assay
An assay for alkaline phosphatase was conducted in the following manner.
COMPONENTS
Buffer: 0.05 M carbonate, 1 mM MgCl 2 at pH 9.5.
Substrate: 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy) phenyl-1,2-dioxetane disodium salt (AMPPD) at 0.4 mM concentration.
Alkaline Phosphatase: stock solution at 1.168 μg/ml in the buffer.
Serial dilutions of alkaline phosphatase stock solutions were made in tubes with final enzyme concentrations of: 4.17×10 -11 M, 8.34×10 -12 M, 1.67×10 -12 M, 3.34×10 -13 M, 6.68×10 -14 M; 1.34×10 -14 M, 3.34×10 -15 M, 1.67×10 -15 M, 8.34×10 -16 M, 4.17×10 -16 M, 2.09×10 -16 M,
PROCEDURE
Duplicate tubes at each of the above concentrations of alkaline phosphatase also containing 0.4 mM AMPPD were incubated at 30° C., for 20 minutes.
After incubation, 30-second light integrals were measured in a Turner 20E Luminometer. The limits of detection of alkaline phosphatase is shown in Table II.
Data for the detection of alkaline phosphatase using 0.4 mM AMPPD is shown in FIG. 3. Light production was linear between 10 -14 to 10 -11 M enzyme.
TABLE II______________________________________ Concentration of Alkaline Minimum Detectable Phosphatase for 2× Conc. of AlkalineAddition Background Phosphatase______________________________________None 1.0 × 10.sup.-14 1.67 × 10.sup.-15 M(1.12)______________________________________ 1. Buffer: 0.05 M sodium carbonate, 1 mM MgCl.sup.2, pH 9.5, Temperature 30° C. AMPPD concentration was 0.4 mM. 2. The number in parentheses is the multiple of background at the indicated concentration.
EXAMPLE 4
Alkaline Phosphatase Assay in the Presence of Bovine Serum Albumin, BSA-Fluor, BDMQ and BDMQ-Fluor
An assay for alkaline phosphatase was conducted in the following manner.
COMPONENTS
BUFFER: 0.05 M sodium carbonate, 1 mM MgCl 2 , at pH 9.5.
Substrate 3-(2'-spiroadamantane)-4-methoxy-4-(3"phosphoryloxy)phenyl-1,2-dioxetane disodium salt (AMPPD) at 0.4 mM concentration.
Alkaline Phosphate: stock solution at 1.168 μg/ml in the buffer.
Conditions Tested:
1. Buffer alone, control.
2. Buffer plus 0.1% bovine serum albumin (BSA).
3. Buffer plus 0.1% BSA-fluorescein (BSA to fluorescein ratio 1 to 3).
4. Buffer plus 0.1% poly[vinylbenzyl(benzyldimethyl-ammonium chloride)] (BDMQ).
5. Buffer plus 0.1% BDMQ and fluorescein (0.01 mg of fluorescein disodium salt mixed with 1 ml of BDMQ).
Serial dilutions of alkaline phosphatase stock solutions were made in tubes at the final enzyme concentrations of: 4.17×10 -11 M, 8.34×10 -12 M, 1.67×10 -12 M, 3.34×10 -13 M, 6.68×10 -14 M, 1.34×10 -14 M, 3.34×10 -15 M, 1.67×10 -15 M, 8.34×10 -16 M, 4.17×10 -16 M, 2.09×10 -16 M, 1.0×10 -16 M, 5.0×10 -17 M, 2 5×10 -17 M.
PROCEDURE:
Duplicate tubes with alkaline phosphatase at concentrations described above also containing 0.4 mM AMPPD were incubated at 30° C. under various conditions. Test tubes were incubated for 20 minutes under conditions 1, 4 and 5, while incubated for 90 minutes under conditions 2 and 3.
After incubation, 30 second light integrals were measured in a Turner 20E Luminometer. The effect of BSA, BDMQ and fluorescein on the limits of detection of alkaline phosphatase is shown in FIG. 4 and Table III. In FIG. 4, --□--corresponds to results under condition 1 above: . . . ▪ . . . condition 2: . . . ◯ . . . condition 3; . . . . . . condition 4; and . . . Δ . . . condition 5, respectively.
TABLE III______________________________________ Concentration of Alkaline Minimum Detectable Phosphatase for 2× Conc. of AlkalineAddition Background Phosphatase______________________________________None 1.0 × 10.sup.-14 .sup. .sup. 1.67 × 10.sup.-15 M (1.12).sup.10.1% BSA 9.5 × 10.sup.-15 M 8.34 × 10.sup.-16 M (1.06)0.1% BSA. 1.3 × 10.sup.-15 M 4.17 × 10.sup.-16 M (1.04)Fluorescein0.1% BDMQ 4.0 × 10.sup.-15 M 1.00 × 10.sup.-16 M (1.07)0.1% BDMQ: 3.4 × 10.sup.-15 M 2.09 × 10.sup.-16 M (1.06)Fluorescein______________________________________ .sup.1 The number in parentheses is the multiple of background at the indicated concentration.
EXAMPLE 5
HSVI DNA Probe Assay
Materials and Buffers
Membrane: Gene Screen Plus, Positively charged nylon membrane.
Buffers:
Denaturation Buffer: 0.5 M NaOH
Neutralization Buffer: 0.4 M NaH 2 PO 4 pH 2.0
Loading Buffer, 1 part Denaturation Buffer, 1 part Neutralization Buffer
Membrane Wetting Buffer: 0.4 M Tris buffer pH 7.5
Membrane Prehybridization Buffer:
______________________________________ Final Concentration______________________________________0.5 ml 100 × Denhardt's 5%solution0.5 ml 10% SDS 0.5%2.5 ml 20 × SSPE 5%2.0 mg denatured, 200 μg/mlsonicated salmonsperm DNAddH.sub.2 O10 ml______________________________________ FinalMembrane Hybridization Buffer: Concentration______________________________________0.5 ml 100 × Denhardt's 5%solution0.5 ml 10% SDS 0.5%2.5 ml 20 × SSPE 5%2.0 mg salmon sperm DNA 200 μg/ml2.0 ml 50% Dextran sulfate 10%ddH.sub.2 O10 mlWash Buffer I:1 × SSPE/0.1% SDS20 ml 20 × SSPE4 ml 10% SDS376 ml ddH.sub.2 O400 mlWash Buffer II: 0.1 × SSPE/0.1% SDSpreheated to wash temperature.2 ml 20 × SSPE4 ml 10% SDS394 ml ddH.sub.2 O400 ml (heatedWash Buffer III:0.1 × SSPE/0.1% SDS20 ml 20 × SSPE4 ml 10% SDS394 ml ddH.sub.2 O400 mlWash Buffer IV:3 mM Tris-HCl (pH 9.5)0.6 ml IM Trizma Base199.4 ml ddH.sub.2 O200.0 ml______________________________________
Dissolved 2 g of polyvinylpyrrolidone mol. wt. 40K (PVP-40) and 2 g of Ficoll at temperatures greater than 65° C. but less than boiling. Cooled the solution to approximately 40° C., added 2 g of BSA and brought the final volume of 100 ml with ddH 2 O. Aliquots were stored at -20° C.
______________________________________20× SSC20× SSC (for 100 ml)3.0 M Sodium Chloride 17.4 g0.3 M Sodium Citrate 8.8 gBring volume to 100 ml and filter througha 0.45 μm nitrocellulose filter. Store atroom temperature.20× SSPE20× SSPE pH 7.4 (for l liter)3.6 M NaCl 210.24 g200 mM Sodium phosphate 23 g dibasic 5.92 g monobasic20 mM EDTA 7.44 gDissolve, adjust pH to 7.4 with 5 N NaOHBring volume to 1 liter and filter througha 0.45 μm nitrocellulose filter.1× TE1× TE buffer 10 MM Tris (pH 7.0) 1 mM EDTA Autoclave______________________________________
Method
1. Prewetted membrane with Wetting Buffer for 15 min.
2. Inserted membrane into a vacuum manifold device.
3. Denatured the DNA sample by adding 50 μl of DNA sample (with known number of copies of HSVI DNA) to 200 μl of Denaturation Buffer. Incubated 10 min. at room temperature. Added 250 ml of ice cold Neutralization Buffer and kept denatured DNA on ice.
4. Added 200 μl of Loading Buffer to each well and aspirated through membrane.
5. Loaded denatured DNA samples to each well, and aspirated through membrane.
6. Repeated Step 4.
7. Dissembled manifold and removed membrane.
8. UV-fixed DNA to membrane using a UV Transilluminator for 5 minutes.
9. Incubated the membrane in 0.1% (w/v) BDMQ in phosphate-buffered saline for 15 minutes.
10. Incubated membrane in Prehybridization Buffer at 70° C. for 1 hour.
11. Added alkaline phosphatase-labeled SNAP probe specific for HSVI dissolved in Membrane Hybridization Buffer. Incubated for 3-5 hours at 70° C.
12. Removed membrane from Hybridization Buffer and incubated in 400 ml of Wash Buffer I, while agitating at room temperature for 10 minutes.
13. Washed with 400 ml of Wash Buffer II at 50° C. for 30 minutes.
14. Washed with 400 ml of Wash Buffer III at room temperature for 10 minutes.
15. Washed with 200 ml of Wash Buffer IV at room temperature for 10 minutes.
16. Added 2 ml of 300 μg/ml AMPPD in 0.1 M Tris buffer, 1 mM MgCl 2 , pH 9.8 to the membrane.
17. Transferred the membranes to a piece of Mylar polyester film, and then to a black box containing Type 612 Polaroid film.
18. Exposed film for 30 minutes. Typical results are shown in FIG. 5, wherein FIG. 5A shows the results at 60 μg/ml AMPPD, FIG. 5B at 300 μg/ml AMPPD, and FIG. 5C after the first 30 min. of reaction at 300 μg/ml AMPPD.
EXAMPLE 6
Hepatitis B Virus DNA Hybridization Assay
We compared the sensitivity of a chemiluminescent substrate (AMPPD) and a chromogenic substrate (BCIP/NBT) for detection of an alkaline phosphate label in Hepatitis B Virus Core Antigen DNA HBV c probe hybridization assay (SNAP®, Dupont). Chemiluminescent signals obtained from AMPPD hydrolysis by said phosphatase was detected with Polaroid Instant Black and White Type 612 film.
Methods and Materials
1. Chemiluminescent Substrate: AMPPD
2. Protocol for Determining the Sensitivity of SNAP®/Test for HBV c (Hepatitis B "Core Antigen" DNA)
The levels of detection, or the sensitivity, of the SNAP® DNA probe test for Hepatitis B "Core Antigen" DNA were determined by performing the test using serially diluted HBV c control plasmid DNA.
The assay protocol involved the following steps:
a. Preparation of Positive HBV c DNA Plasmic Controls
A stock solution of HBV c plasmid was prepared by dissolving 100 ng (1.2×10 10 copies) of the plasmid in 25 ul of sterile, deionized H 2 O and serially diluted with 0.3 N NaOH to produce plasmid samples in the concentrations range of 4.88×10 3 -0.96×10 8 a copies/ul. The samples were allowed to denature for 15 minutes at room temperature.
b. Preparation of the Membranes. Immobilization of HBV c Plasmid Control DNA
Gene Screen® Plus membranes were cut into 1×8 cm strips. 1 ul of each dilution of HBV c plasmid sample was spotted on the dry membrane with a pipette tip in contact with the membrane surface to obtain very small, concentrated spots. The membranes were then rinsed with 100 ul of 2 M ammonium acetate per spot to neutralize the target immobilized nucleic acid. They were subsequently rinsed with 0.6 M sodium chloride, 0.08 M sodium citrate, pH 7.0 buffer.
c. Probe Hybridization
(i)-Prehybridization
The membranes containing plasmid samples were placed in a heat-sealable pouch in 3 ml of Hybridization Buffer. Prehybridization was carried out for 15 minutes at 55° C.
(ii)-Hybridization
SNAP® alkaline phosphatase labeled probe was reconstituted with 100 ul of the sterile deionized H20. The hybridization solution was prepared using 2.5 ul alkaline phosphatase labeled probe solution dissolved in 0.5 ml Hybridization Buffer. Hybridization was performed in a new, heat sealed pouch, with 0.5 ml hybridization solution, for 30 minutes at 55° C. After hybridization, the pouch was opened and the membranes carefully removed and washed with the following buffers:
1. twice with 0.1 M sodium chloride, 0.02 M sodium citrate, pH 7.0, plus 10 g SDS buffer, for 5 minutes at room temperature,
2 twice with 0.1 M sodium chloride, 0.02 M sodium citrate, pH 7.0, plus 10 ml Triton X-100 (Sigma Chemical Co., St. Louis, Mo.), for 5 minutes at 55° C.,
3. twice with the above buffer for 5 minutes at room temperature,
4. twice with 0.1 M sodium chloride, 0.02 M sodium citrate, pH 7.0 buffer for 5 minutes at room temperature,
5. once with 0.1% BSA in 0.05 M carbonate buffer at pH 9.5.
Hybridization Buffer was prepared by mixing 250 ml of 3 M sodium chloride, 0.4 M sodium citrate, pH 7.0, diluted to 800 ml with deionized H 2 O, with 5 g Bovine Serum Albumin, 5 g polyvinylpyrrolidone (average MW 40,000) and 10 g SDS, warmed and mixed to dissolve.
d. Chemiluminescent Detection of HBV c Plasmid DNA with AMPPD
The hybridized membrane strips were saturated with 100 ul of 1.6 mM AMPPD in 0.1% BSA in 0.05 M carbonate Buffer, 1.0 mM MgCl 2 at pH 9.5. The membranes were then sealed in a plastic pouch and immediately placed in a camera luminometer where light emission was imaged on Polaroid Instant Black/White 20,000 ASA film.
e. Detection with SNAP® Chromogenic Substrates (Nitro Blue Tetrazolium (NBT) 5-Bromo-4-Chloro-3-Indoly Phospate (BCIP) (Performed According to the Manufacturer's Instructions)
Hybridized membranes which were developed with the chromogenic substrates did not undergo wash step #5. Substrate solution was prepared by mixing 33 ul NBT and 25 ul of BCIP in 7.5 ml of alkaline phosphatase substrate buffer provided by the manufacturer. Washed hybridized membranes were transferred to a heat sealed pouch with the substrates containing buffers. The color was allowed to develop in the dark, as NBT is light sensitive.
f. Photographic Detection of AMPPD Signal
The results of assays performed with AMPPD were imaged on Polaroid Instant Black and White Type 612 photographic film. The images were subsequently digitized using a black and white RBP Densitometer, Tobias Associates, Inc., Ivyland, Pa.
Results
FIG. 6 shows a time course of the chemiluminescent assay for serially diluted Hepatitis B Virus "Core Antigen" plasmid DNA hybridized with alkaline phosphatase labeled probe and imaged onto photographic film. Each photograph corresponds to a 30 minute exposure on Polaroid Instant Black and White Type 612 film. A comparable set of serially diluted Hepatitis B Virus "Core Antigen" plasmid DNA hybridized with alkaline phosphatase labeled probe and detected BCIP/NBT substrate is shown in FIG. 7. The chemiluminescent assay detected 1.18×10 6 copies of HBV c DNA. The colorimetric test showed a detection of 1.07×10 7 copies. After a two hour incubation, the chemiluminescent assay detected 4.39×10 4 copies of HBV c DNA. The colorimetric test showed a detection of 1.07×10 7 copies after the same incubation time. After a 4 incubation, the colorimetric assay detected 1.18×10 6 copies of HBV c DNA.
Table IV summarizes the results of chemiluminescent detection limits of HBV c using AMPPD and the colorimetric detection with BCIP/NBT substrates. Sensitivity of the SNAP® hybridization kit was improved over 100-fold using the chemiluminescent assay based upon AMPPD. The AMPPD-based assay detected as few as about 44,000 copies of HBV c plasmid DNA, compared to the BCIP/NBT colorimetric assay which required 10,700,000 copies for detection. In addition, AMPPD reduced the assay time from 4 hours to 30 minutes.
TABLE IV______________________________________Comparison of Detection Limits for Hepatitis B"Core Antigen" Plasmid DNA Using Chemiluminescentand Chromogenic Substrates in SNAP ® Hybridization Kit Chemiluminescent AMPPD ColorimericCopies of BHS.sub.c Substrate BCIP/NBT SubstratesDNA Per Spot Detection in Minutes Detection in Minutes______________________________________ 9.8 × 10.sup.7 30 30 3.2 × 10.sup.7 30 601.07 × 10.sup.7 30 1203.56 × 10.sup.6 30 1801.18 × 10.sup.6 30 2403.95 × 10.sup.5 60 no color1.31 × 10.sup.5 90 no color4.39 × 10.sup.4 120 no color______________________________________
Quantitative chemiluminescence results could be obtained by measuring reflection densities directly from the imaged Black and White Polaroid Type 612 instant photographic film strips using a Tobias RBP Black and White Reflection Densitometer, as shown in FIG. 8. The results show that a dose response curve can be generated of the reflection densities as a function of HBV c plasmid concentration. This dose response curve can be subsequently used as a calibration for the determination of HBV c DNA levels in clinical specimens.
EXAMPLE 7
Bead Format AFP Elisa Assay for Alpha Feto Protein (AFP).
Anti-AFP antibody coated beads and anti-AFP antibody: alkaline phosphatase conjugates were obtained from a Hybritech Tandem Assay kit.
1. To each tube was added 20 μl of sample. Samples were 0, 25, 50, 100, and 200 mg/ml AFP.
2. Placed one bead in each tube.
3. Added 200 μl of anti-AFP antibody alkaline phosphatase conjugate to each tube.
4. Shook rack to mix contents of tubes.
5. Covered tubes.
6. Incubated for 2 hours at 37° C.
7. Aspirated off antibody and sample to waste.
8. Washed beads 3 times with 2.0 ml of.0.1% Tween 20 in phosphate buffered saline, pH 7.4.
______________________________________For Colorimetric Assay Chemiluminescence______________________________________ 9. N/A 9. Washed 1 time with 0.5 M carbonate, 1 mM MgCl.sub.2 pH 9.5.10. Added 200 μl of 1 mg/ml 10. Added 2.50μ of 0.4 mMp-nitrophenyl-phosphate AMPPD in 0.05 M in 0.1(PNPP) glycine 1 mM carbonate, 1 mM MgCl.sub.2 pHMgCl.sub.2 pH 10.4 9.511. Incubated for 30 minutes 11. Incubated for 20 minutesat room temperature at 30° C.12. Added 1.5 ml of 0.1 M gly- 12. N/Acine, 10 mM EDTA, pH9.5 to stop color devel-opment13. Read in absorbance at 410 13. Read 10 sec. integral ofmm in spectrophotometer each tube in Turner luminometer______________________________________
14. Plotted both sets of data as the signal at each concentration of AFP divided by the signal at zero AFP vs. concentration of AFP. As shown in FIG. 9, the results of the colorimetric assay are shown in the PNPP curve, and that of the chemiluminescence assay in the AMPPD curve. It can be seen that the latter assay is about 10 times as sensitive as the former assay.
EXAMPLE 8
Assay for Thyroid Stimulating Hormone (TSH)
Materials
Mouse monoclonal anti-TSH-β antibody was used to coat 1/8 inch beads for analyte capture. Mouse monoclonal anti-TSH antibody was conjugated with alkaline phosphatase and used as a detection antibody (antibody- enzyme conjugate).
TSH was obtained from Calbiochem, Catalog No. 609396, and BSA (type V--fatty acid free) was obtained from Sigma, Catalog No. A6003.
The buffer solution used for the analyte and antibody enzyme conjugate contained 0.1 M Tris-HCl, 1 mM MgCl 2 , and 2% by weight BSA (pH 7.5). The substrate buffer solution contained 0.1 M Tris, 0.1 mM MgCl 2 , (pH 9.5), and the substrate AMPPD (50 μg/ml)
PROTOCOL
A TSH-containing analyte solution (15 μl) was mixed with 135 μl of antibody enzyme conjugate solution. Two 1/8 inch beads coated as described above were added to the solution and incubated for 2 hours at 23° C. The beads were then washed four times with 0.1 M Tris buffer (pH 7.5) and transferred to a reaction tube. 200 μl of the buffer solution containing the substrate described above was added to the tube. Following an incubation period of 20 minutes, light emission was recorded as ten second counts using a Berthold Clinilumat Luminescence Analyzer.
FIG. 10, which is a plot of the data in Table V below, shows luminescence intensity for a given TSH concentration. Linearity was achieved between 1 and 8 μU/ml of TSH.
TABLE V______________________________________TSH Concentration(μU/ml) (Counts/10 sec × 10.sup.-4)______________________________________1 0.252 0.494 1.1______________________________________
An identical TSH assay was also performed in the absence of BSA for the sake of comparison. As shown in FIG. 11, the BSA-containing sample (Curve A) showed greater luminescence intensity for a given TSH concentration than the sample without BSA (Curve B).
EXAMPLE 9
Assay for Carcinoembryonic Antigen (CEA) in the Bead Format
Anti-CEA coated beads and anti-CEA antibody: alkaline phosphatase conjugates were obtained from a Hybritech Tandem Assay kit.
1. To each tube were added 20 μl of sample. Standards of 0, 2.5, 5, 10, 20, and 50 ng/ml CEA were used.
2. One bead was placed in each tube.
3. Added 200 μl of anti-CEA antibody enzyme conjugate to each tube.
4. Shook rack to mix contents of tubes.
5. Covered tubes.
6. Incubated for 2 hours at 37° C.
7. Aspirated off antibody and sample to waste.
8. Washed beads 3 times with 2.0 ml of 0.1% Tween 20 in phosphate buffered saline, pH 7.4.
9. Washed once with 0.05 M sodium carbonate, 1 mM MgCl 2 , pH 9.5.
10. Added 250 μl of 0.4 mM AMPPD in 0.05 M sodium carbonate, 1 mM MgCl 2 , pH 9.5.
11. Incubated for 20 minutes at 30° C.
12. Read 10 sec. integral of luminescence from each tube in Turner 20E Luminometer.
13. Plotted both sets of data as the signal at each concentration of hCG divided by the signal at zero CEA vs. concentration of CEA. Typical data for a CEA assay using AMPPD are shown in FIG. 12. Linearity was achieved between 0 and 20 ng/ml of CEA.
EXAMPLE 10
Assay for Human Luteinizing Hormone (hLH)
A nylon membrane, (Pall Immunodyne, 0.45 micron pore size), approximately 3 mm in diameter wa sensitized with 5 μl of a solution of 1 μg/ml of capture monoclonal anti-LH antibodies for solid phase in phosphate buffered saline (PBS), purchased from Medix, catalog #L-461-09. The membrane was subsequently blocked with 2% casein in phosphate buffered saline at pH 7.3. The membrane was then enclosed in the device shown in FIG. 13, which included blotting paper layers. In FIG. 13, A shows the prefilter cup; B plexiglass top; C Pall Immunodyne membrane (pore size 0.45 μ); D polypropylene acetate fluffy layer; E blotting paper; and F plexiglass.
The detection antibody used was mouse monoclonal anti-LH, purchased from Medix, catalog #L-461-03. This antibody was derivatized with alkaline phosphatase, (purchased from Biozyme, catalog #ALPI-11G), using the glutaraldehyde coupling procedure [Voller, A. et.al., Bull. World Health Org., 53, 55 (1976)].
Procedure
The detection antibody conjugate (50 μl) was added to tubes containing 200 μl of hLH of the following concentrations:
______________________________________Tube # Conc. hLH in ng/ml of PBS______________________________________1 02 13 104 100______________________________________
The content of each tube was then added to four nylon membranes previously derivatized with capture antibodies (described above). After a five minute incubation period, the prefilter cup was removed and the membranes were washed with 400 μl of 0.05% Tween 20 in PBS. Subsequently, 100 μl of 0.4 mM AMPPD, in 0.05 M carbonate, 1 mM MgCl 2 , 0.1% by weight BSA at pH 9.5 were added. The nylon membranes were placed in a camera luminometer containing type 612 Polaroid Instant Black and White film, and exposed for one minute. The results of the assay imaged on film are shown in FIG. 14.
Subsequently, the reflection densities of the images were measured using the Tobias RBP Portable Black and White Reflection Densitometer (manufactured by Tobias Associates, Inc., 50 Industrial Drive., P.O. Box 2699, Ivyland, Pa. 18974-0347). The reflection densities were plotted versus concentration of LH to yield a standard curve for hLH, as shown in FIG. 15.
EXAMPLE 11
Chemiluminescent Decomposition of 3-(2'spiroadamantane)-4-methoxy-4-(3"β-D-galactopyranosyl-phenyl)-1,2-dioxetane (AMPGD)
Reagents
1. AMPGD synthesis as described above was made up in 1:1 MeOH/H 2 O at a concentration of 10 mg/ml.
2. 0.01 M sodium phosphate buffer, pH 7.3, containing 0.1 M NaCl and 1 mM MgCl 2 .
3. β-Galactosidase (Sigma Chem. Co., catalog G5635, mol. wt. 500,000), 1 mg/ml in phosphate-salt buffer, pH 7.3, diluted 1:100 to yield a 2×10 -8 M solution.
Protocol
AMPGD solution (9.3 μl) was diluted in 490 μl of a buffer solution of variable pH. Subsequent addition of 5 μl of the diluted β-galactosidase solution was followed by 1 hr. incubation at 37° C. The final concentration of reactants was 0.4 mM AMPGD and 1×10 -13 moles β-galactosidase, at various pH values, as required by the experiment.
After incubation, the solutions were activated in a Turner 20E Luminometer by the addition of 100 μl of 1 N NaOH. The instrument temperature was 29° C., that of the NaOH room temperature.
Thus, the assay consisted of a two-step process wherein the substrate-enzyme incubation was performed at various pH values appropriate to efficient catalysis, e.g., at pH 7.3, and subsequently the pH was adjusted to about 12 with NaOH, and luminescence was read again.
Results
In FIG. 16 is shown the chemiluminescence of a fixed concentration of AMPGD as a function of β-galactosidase concentration, wherein the enzyme reaction was run at pH 7.3 and luminescence measured at pH 12. The useable, i.e., linear, portion of the standard curve was at enzyme concentrations between 10 -13 and 10 -8 M.
In FIG. 17 is shown the effect of pH on the decomposition of AMPGD by β-galactosidase. The data show that the optimum pH for the enzyme with this substrate is about pH 6.5.
FIG. 18 shows the production of light from AMPGD as a function of β-galactosidase concentration, using the two-step protocol described above. At all enzyme concentrations, adjustment of the pH to 12 from 7.3 produced over a 100-fold increase in chemiluminescence.
EXAMPLE 12
Detection of DNA Fragments by Chemiluminescence After Electrophoretic Separation of Fragments
DNA sequencing was performed using the dideoxy chain termination method of Sanger et al. (1977) above.
Biotinylated pBR322 primer (40 ng) was annealed to 5 μg of denatured pBR322 plasmid. Klenow Fragment (DNA polymerase I), 2 units, was then added (final volume was 17 μl). Subsequently, 2 μl of this template - primer solution was used for each of four base-specific reactions (G, A, T, C). To each reaction mixture, we added these specific amounts of deoxynucleotides, and dideoxynucleotides.
______________________________________Reaction Mixtures(Nanograms of Nucleotides) G A T C______________________________________DeoxynucleotidesdGTP 1022.9 1077.4 1102.9 1102.9dCTP 1015.9 992.4 1015.9 942.9dTTP 1048.6 1048.6 972.5 1048.6dATP 985.5 985.5 985.5 985.5DideoxynucleotidesdGTP 123.0 -- -- --dCTP -- 29.7 -- --dTTP -- -- 466.0 --dATP -- -- -- 113.0______________________________________
An aliquot of each reaction mixture (1 μl) was loaded on a standard sequencing gel and electrophoresed. The DNA was electrophoretically transferred to a Pall Biodyne A nylon membrane and then UV fixed to the membrane. The membrane was then dried, blocked for 1 hour with 0.2% casein in PBS (casein-PBS), incubated with streptavidin:alkaline phosphatase (1:5000 in casein-PBS) for 30 minutes, washed first with casein-PBS, then with 0.3% Tween 20 in PBS, and finally with 0.05 M bicarbonate/carbonate, pH 9.5, 1 mM MgCl 2 . Substrate, 0.4 mM AMPPD in the final wash buffer, was incubated with the membrane for 5 minutes. After wrapping the membrane in plastic wrap, the membrane was placed in contact with Kodak XAR film and Polaroid Instant Black and White film for 2 hours. The order of sequence lanes is C T A G in FIGS. 19A (X-ray film) and 19B (instant film).
EXAMPLE 13
Effect of Membrane Composition on Detection of DNA Fragments by Chemiluminescence
Various amounts of the SNAP® Hepatitis B core antigen oligonucleotide probe conjugated to alkaline phosphatase (Molecular Biosystems, Inc., San Diego, Calif.), as listed in the left column of Table VI, were spotted on three types of transfer membranes: Gene Screen Plus™ (Nylon), Schleicher and Schuell nitrocellulose, and Millipore PVDF. The spots were incubated with an AMPPD solution, luminescence generated, and light detected on instant film, as in Example 6(C).
The data of Table VI show the earliest detection times at each level of oligonucleotide for each of the three membranes. Luminescence was greatly increased in intensity by the use of nylon-based membranes, as compared to the other two types. For example, with a nylon membrane, the smallest amount of oligonucleotide tested, i.e., 0.01 ng, was detected within 60 seconds of film exposure. In contrast, it required at least 67 ng of oligonucleotide to be detectable in 60 seconds on a nitrocellulose membrane; amounts of 0.82 ng or less were not detectable within 10 minutes. In further contrast, no amount of oligonucleotide was detectable in periods as long as 10 minutes.
TABLE VI______________________________________Oligonucleotide, Earliest Detection Time, Sec.ng Nylon Nitrocellulose FVDF______________________________________200 1 60 *67 1 60 *22 1 300 *7.4 1 300 *2.5 1 300 *0.82 1 * *0.27 1 * *0.091 10 * *0.03 60 * *0.01 60 * *______________________________________ *Not detectable by 10 min. of exposure.
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In an assay method in which a member of a specific binding pair is detected by means of an optically detectable reaction, the improvement wherein the optically detectable reaction includes the reaction, with an enzyme, of a dioxetane having the formula ##STR1## where T is a cycloalkyl or polycycloalkyl group bonded to the 4-membered ring portion of the dioxetane by a spiro linkage; Y is a fluorescent chromophore; X is hydrogen, alkyl, aryl, aralkyl, alkaryl, heteroalkyl, heteroaryl, cycloalkyl, cycloheteroalkyl, or enzyme-cleavable group; and Z is hydrogen or an enzyme-cleavable group, provided that at least one of X or Z must be an enzyme-cleavable group, so that the enzyme cleaves the enzyme-cleavable group from the dioxetane to form a negatively charged substituent bonded to the dioxetane, the negatively charged substituent causing the dioxetane to decompose to form a luminescent substance that includes group Y of said dioxetane.
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BACKGROUND OF THE INVENTION
The present invention relates to sun porches, which are ⃡greenhouse⃡-type units to be added on to an existing building structure.
Sun porches have gained increasing popularity as a means of expanding residential living space without significant structural changes. A sun porch is typically sold in kit form for assembly and installation by a skilled carpenter or other craftsman. However, known sun porches are not without their drawbacks. Most notably, constructions to date have been relatively complicated and required the skills of a carpenter or other skilled worker for installation of the unit. Consequently, assembly of known sun porches is relatively expensive and simply beyond the capabilities of many homeowners and other "do-it-yourselfers⃡.
SUMMARY OF THE INVENTION
The aforementioned problems are overcome in the present invention wherein a sun porch is provided which can be relatively easily and rapidly assembled and installed by homeowners and other "do-it-yourselfers⃡ having limited construction skills.
In a first aspect of the invention, the sun porch includes a wall assembly including a plurality of modular interfitting window panels. Each window panel includes a frame having opposite male and female side members. The side members of adjacent window panels interfit permitting easy assembly while still providing the requisite weather sealing therebetween. Preferably, the sun porch further includes corner posts for interconnecting two of the window panels at a corner. If included, the corner post includes a male portion for receiving the female side member of one window panel and a female portion for receiving the male side member of the other wall panel. Further preferably, the sun porch includes male and female wall rails to be mounted to the existing building structure and which interfit with female and male side members, respectively, on window panels to complete the modular scheme. The described construction greatly facilitates the assembly of the sun porch wall.
In a second aspect of the invention, the sun porch includes a novel base means for easily leveling the window panels. More specifically, the base includes an H-channel adjustably supported on threaded members anchored in the sun porch concrete floor. The downwardly depending legs of the H-channel hide the leveling mechanism; while the upwardly extending legs of the H-channel receive the lower edge of the modular wall panels. The H-channel further includes means for spacing the wall panels above the web portion of the H-channel to provide a clearance for the leveling/tie-down mechanism. Consequently, the base is both functional and aesthetically pleasing. The base can be fully and accurately leveled throughout its length, and yet the leveling mechanism is totally hidden within the assembled unit.
In a third aspect of the invention, a door assembly is provided which can be substituted for one or more of the window panels. In this embodiment, the window panels each have a generally uniform width and the door has a width which is a multiple of the window panel width. Further, the door frame includes male and female side frame members to interfit with the side frame members of the modular window panels. Consequently, the door can be easily substituted for one or more window panels in the sun porch wall to provide a means for ingress to and egress from the sun porch interior. This construction maintains the modularity of the sun porch wall assembly while still providing a means of access to the sun porch.
In a fourth aspect of the invention, a novel roof assembly is provided for easily and effectively sealing the roof panels within the supporting structure. Specifically, the roof assembly includes a plurality of rafters each having sealing means extending longitudinally along the upper surface thereof. A window panel is mounted between each pair of rafters, and the adjacent window panels on each rafter are spaced from one another. A retainer is provided having a length substantially identical to the rafter and including sealing means on its underside for engaging the window glass. Fasteners extend between the retainer and the rafter to secure the retainers in position and enhance the weather seal therebetween. The fastener means are located between the adjacent roof panels. The described construction is relatively simple, is easily assembled, and yet provides the requisite weather seal.
In a fifth aspect of the invention, the roof includes an easily assembled beam-and-rafter roof construction. Specifically, the roof assembly includes a pair of spaced beams each of which includes support members protruding therefrom toward the opposite beam. Each rafter extends between the two beams and includes a connector means which slides into engagement with the support means as the rafter is placed in position. The connector means on the rafter and the support means on the beam are both confined within the cross-sectional configuration of the rafter or its imaginary longitudinal extension. Consequently, the interconnecting structure is hidden from view in the assembled roof. Again, the structure facilitates assembly of the roof by permitting the rafters to be simply slid into position. Further, the construction provides an aesthetically pleasing appearance since the fastening mechanism is hidden from view.
These and other objects, advantages, and features of the invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiment and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present sun porch;
FIG. 2 is a front elevational view of the sun porch;
FIG. 3A is a sectional view of the base showing the tie-down assembly taken along line III--III in FIG. 1;
FIG. 3B is a sectional view similar to FIG. 3A showing the height-adjustment assembly;
FIG. 4 is a fragmentary sectional view of two interfitted window panels taken along line IV--IV in FIG. 1;
FIG. 5 is a fragmentary sectional view of the corner post assembly taken along line V--V in FIG. 1;
FIG. 6 is a fragmentary sectional view of the left wall rail assembly taken along line VI--VI in FIG. 1;
FIG. 7 is a fragmentary sectional view of the right wall rail assembly;
FIG. 8 is a fragmentary horizontal sectional view of the sliding door frame;
FIG. 9 is a right side elevational view of the sun porch showing an optional swing door;
FIG. 10 is a fragmentary horizontal sectional view of the swing door;
FIG. 11 is a fragmentary sectional view of the left triangle assembly taken along line XI--XI in FIG. 1;
FIG. 12 is a fragmentary top plan view of a rafter with the gaskets removed;
FIG. 13 is a sectional view of a rafter taken along line XIII--XIII in FIG. 2;
FIG. 14 is a fragmentary top plan view of a purlin with the gaskets removed; and
FIG. 15 is a fragmentary sectional view of the roof assembly taken along line XV--XV in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A sun porch constructed in accordance with a preferred embodiment of the invention is illustrated in FIGS. 1 and 2 and generally designated 10. The sun porch is shown mounted on a concrete pad or slab 11 and is attached to an existing building 12. The construction of the sun porch is generally modular including a base 14, a plurality of modular window panels 16, a pair of corner posts 18, a pair of triangles 20, and a roof assembly 22. The wall panels 16 are supported by the base 14 which is in turn anchored to the concrete pad 12. The triangles 20 and the roof assembly 22 provide a roof for the unit so that it is fully enclosed from the weather.
The term sun porch as used herein refers to a primarily glass enclosure adapted to be attached or connected to a building. Other names for these units are sun sheds and greenhouses.
I. Base
The base construction 14 (FIGS. 3A and 3B) supports the wall panels 16 above the concrete pad 11. The base includes a tie-down assembly 110, a C-channel 112, a height-adjustment assembly 110', and an H-channel 114. A plurality of the tie-down height-adjustment assemblies 110 and 110' are provided along the length of the base assembly 14, preferably on 301/2-inch centers and alternating with each other so that one of the assemblies 110 or 110' are provided on 151/4-inch centers.
All extrusions illustrated and/or described in the present application are preferably fabricated of aluminum with urethane thermal breaks. The fabrication of such extrusions is generally well-known to those skilled in the extrusion art. Of course, suitable substitute materials could also be used.
The C-channel (FIG. 3B) is thermally broken extrusion including an exterior portion 129, an interior portion 131, and a thermal break 133. The exterior portion includes a web portion 130 which defines a channel 135 in its underside. One aperture 136 is formed in the floor of the groove 135 on each 151/4-inch center to receive either a tie-down assembly 110 or a height-adjustment assembly 110'. A pair of side flanges 132 and 134 extend upwardly from the opposite edges of the web portion 130; and the flange 134 defines a thermal-break channel 137. The exterior portion 131 defines a thermal-break channel 139 and a bulb-seal channel 141 on opposite sides thereof. The thermal break 133 fills both channels 137 and 139 to interconnect the two portions 129 and 131. A bulb seal 143 is supported within the channel 141 to provide a seal between the C-channel 112 and the H-channel 114. Preferably, butyl caulk or other appropriate glazing compound is placed between the pad 11 and the C-channel 112 prior to installation of the C-channel.
Each tie-down assembly 110 (FIG. 3A) includes an anchor bolt 116, a flat washer 120, and a hex nut 122. The anchor bolt 116 is embedded within the concrete pad 11 on 301/2-inch centers preferably prior to setting of the concrete. Alternatively, the anchor bolt 116 can be installed subsequent to setting of the pad 11. The holes 136 in the C-channel 112 are aligned with the bolts 116 when the C-channel is placed thereover. The flat washer 120 and hex nut 122 are positioned on the bolt 116 and tightened against the channel 135 to secure the C-channel 112 against the pad.
Each height-adjustment assembly 110' (FIG. 3B) includes a hex bolt 116', flat washers 120', 122', and 124', and hex nuts 126', 128', and 130'. The bolt 116' extends upwardly through the aperture 136 in the C-channel 112 so that the head is received and locked within the channel 135. The flat washer 122' and the hex nut 126' are positioned on the bolt 116' and tightened against the C-channel 112 to secure the bolt in position. The height-adjustment hex nut 128' and the washer 122' are positioned on the bolt 116' so that all hex nuts 128' are horizontally level with one another. The H-channel is supported on the hex nuts 128' by fitting the holes 167 over the bolts 116'. Finally, the flat washer 124' and the tie-down hex nut 130' are tightened against the H-channel to secure the H-channel in its height-adjusted and horizontally level position.
The H-channel 114 (FIG. 3B) is supported by the height-adjustment assemblies 110. The H-channel is a thermally broken extrusion including an exterior portion 140, an interior portion 142, and a thermal break 144. The exterior portion 140 includes a generally planar outer wall 145 including, along its inner surface, an integral bulb-seal channel 146, a panel support flange 148, and a thermal-break channel 150 supported on a flange 152. The bulb-seal channel 146 is at the top or upper edge of the outer wall 145, while the panel support 148 is located therebelow.
The interior portion 142 (FIG. 3) includes an interior wall 154 and web flange 156, a support flange 158, and a pair of support flanges 160 and 162. The inner wall 154 defines an integral bulb-seal channel 164 and an integral panel support 166. The bulb-seal channel is located along the top or upper edge of the interior wall 142, while the panel support flange 166 is located therebelow. The web flange 156 is generally perpendicular to the inner wall 154 and generally coplanar with the support flange 152 of the exterior extrusion 140. One aperture 167 is formed in the web flange and aligned with each height-adjustment assembly 110. The first panel-support flange 160 extends upwardly from the junction of the web flange 156 and the support flange 158. The second panel support flange 162 extends upwardly from the terminal edge of the support flange 158. An integral thermal break channel 168 is located at the junction of the support flange 158 and the panel support flange 162. Both of the panel-support flanges 160 and 162 terminate in a broadened foot portion 170 and 172, respectively, to provide improved support for the panel 16. The panel supports 148, 166, 170, and 172 lie within a common horizontal plane to support the planar lower surface of the panel 16.
A thermal break 144 is interposed between the outer and inner portions 140 and 142 to provide thermal insulation therebetween. Specifically, the thermal break 144 fills both thermal-break channels 150 and 168 and spaces the two portions one from the other.
The wall panels 16 are supported within the base assembly 14 by sliding the wall panel between the outer and inner walls 144 and 154 and resting the wall panel on the supports 148, 166, 170, and 172. The lower portions of the outer wall 144 and the inner wall 154 extend downwardly over the walls 132 and 134, respectively, of the C-channel 112 to hide the C-channel in the completed assembly.
II. Wall Panels
The wall panels 16 (FIGS. 1, 2, and 4) are each generally identical to one another, having a uniform width, and therefore are modular or interchangeable in the sun porch construction. As seen more specifically in FIG. 4, each panel 16 includes a glass 30 which, as illustrated, is double insulated glass. Alternatively, the glass 30 could be virtually any transparent or translucent material. Options currently available include tempered safety glass and other clear or bronze-tinted glasses. Each glass 30 is surrounded by, or enclosed within, a thermally broken frame 32 which includes a female side frame member 34 and a male side frame member 36.
The female side frame member 34 (FIG. 4) is a thermally broken extrusion including an outer portion 40, an inner portion 42, a thermal break 44, and a glass retainer 46. The outer portion 40 is generally planar and terminates at its glass end in a spacer leg or flange 48 which engages the glass 30. The outer portion 40 defines an integral thermal-break channel 50 and an integral glazing support 52. A glazing material (not shown), such as butyl caulk, is positioned on the glazing support 52 to engage the glass 30. The slight separation of the glazing support 52 and the flange 48 insures that glazing will not squeeze out into the viewing area of the glass 30 beyond the spacer flange.
The inner portion 42 (FIG. 4) is generally rectangular in cross section and includes an inner leg 60 extending from one corner of the rectangular shape. The inner portion 42 includes an integral thermal-break channel 62, integral screw channels 64 and 66, an integral screw channel 68, and a retainer channel 70. The screw channels 64 and 66 receive screws (not shown) at the corners of the frame 32 to interconnect the various frame members. The screw channel 68 opens through a visible portion of the inner extrusion 42 to provide an attachment means for accessories such as blinds and/or quilts. The retainer channel 70 receives the generally L-shaped retainer 46 to secure the glass 30 in position against the flange 48 and the glazing support 52. A panel-receiving channel 72 is defined between the inner leg 60 and the outer extrusion 40. The width of the female channel 72 is dimensioned to closely receive the male frame member 36 as will be described.
A thermal break 44 (FIG. 4) interconnects the outer and inner portions 40 and 42 in conventional fashion. The thermal break 44 completely fills the channels 50 and 62 to intersecure these pieces. Thus, the inner extrusion 42 is thermally insulated from the outer extrusion 40 by the thermal break 44.
The male side frame member 36 (FIG. 4) is dimensioned to fit within the female member 34. The male member 36 is a thermally broken extrusion including an outer portion 80, an inner portion 82, a thermal break 84, and a retainer 86. The outer portion 80 includes a glazing supporting portion 88, a thermal-break channel 90, and a bulb-seal channel 92. The portion 88 is serrated or grooved in the area facing the glass 30 to receive glazing compound to provide a weather seal against the glass. The bulb seal channel 92 faces the frame exterior and receives a conventional bulb seal to seal the male frame side member against the female side frame member in the assembled sun porch.
The inner portion 82 (FIG. 4) is generally rectangular in cross section and integrally defines a thermal-break channel 94, a bulb-seal channel 95, a pair of interior screw channels 96 and 98, an exterior screw channel 100, and a retainer channel 102. A bulb-seal is mounted in the channel 9 to seal the male side member 36 against the female side member 34. The screw channels 96 and 98 receive screws (not shown) to interconnect the various frame members to form the frame 32. The screw channel 100 opens through a visible interior portion of the frame to provide an attaching means for accessory hardware such as blinds and/or quilts. The retainer channel 102 receives a generally L-shaped retainer 86 to secure the glass 30 against the glazing portion 88.
A thermal break 84 (FIG. 4) interconnects the outer and inner portions 80 and 82. Specifically, the thermal break 84 fills both thermal-break channels 90 and 94 to interconnect and space the extrusions one from the other. Consequently, the inner extrusion 82 is thermally insulated from the outer extrusion 80 via the thermal break 84.
As illustrated in FIG. 4, adjacent window panels 16 interfit in male/female relationship throughout the height of all engaging edges. Specifically, the male side frame member 36 is closely received within the female side member 34 of an adjacent window panel. The bulb seals carried within the bulb-seal channels 92 and 95 are compressed as the two panels are interfitted to provide a tight weather seal therebetween.
III. Corner Posts
The corner post 18 (FIG. 5) interconnects two nonlinearly aligned wall panels 16. In the preferred embodiment, the corner post 18 joins the two panels at a 90° angle. The corner post is a thermally broken extrusion including a body portion 180, an inner portion 182, a first connector portion 184, and a second connector portion 186.
The body portion 180 (FIG. 5) includes an L-shaped exterior wall 188 from which extend connector flanges 190 and 192 and a stop flange 193. The connector- rod socket 194 is supported by perpendicular support flanges 196 and 198 which are integrally connected to connector flanges 190 and 192, respectively. The connector flange 190 terminates in a thermal-break channel 200. The support flange 198 terminates in a perpendicular mounting flange 202. The exterior wall 188 includes a reduced portion 204 which terminates in an integral bulb-seal channel 206.
A connector rod 207 extends the full height of the corner post 18 and is anchored at its lower end in the base 14 and at its upper end to the front cap assembly 480 to be described.
The interior portion 182 (FIG. 5) is generally L-shaped including a first wall 208 and a second wall 210. An L-shaped flange 212 extends inwardly from the first wall 208; while the second wall 210 includes an inwardly facing bulb-seal channel 214 and an outwardly facing thermal-break channel 216.
The connector portion 186 (FIG. 5) at a first end is secured to the mounting flange 202 and at its opposite end defines an integral thermal-break channel 218. A thermal break 220 interconnects the inner portion 210 from the mounting portion 186. Specifically, the thermal break fills both channels 216 and 218 and spaces the two portions one from the other.
The connector portion 184 (FIG. 5) defines an integral thermal-break channel 222 and a flange 224 which interfits within the L-flange 212. A thermal break 226 interconnects the body portion 188 and the connector portion 184 to intersecure the pieces and provide thermal insulation therebetween. Specifically, the thermal break fills both channels 200 and 222 and spaces the portions one from the other.
The L-flange 212 and the stop flange 193 lie within a common plane perpendicular to the outer wall 188 (FIG. 5). The outer wall 188, the inner wall 208, and the stops 212 and 193 thereby define a channel for receiving a male side member 36 as illustrated in FIG. 5. Similarly, the reduced portion 204 and the inner wall 210 define a male portion dimensioned to receive a female side member 34 thereover. Consequently, the corner post 18 receives the male side frame member of one panel and the female side frame member of a second panel to interconnect the two panels at an angle and to continue the male/female scheme through the corner of the sun porch 10.
IV. Wall Rails
FIGS. 6 and 7 illustrate the attachment of the window panels to the existing building wall 12 (see FIG. 1 also). FIG. 6 illustrates the attachment of the left wall panel (when the sun porch 10 is viewed from the front), while FIG. 7 illustrates the attachment of the right wall panel.
The left wall rail 230 (FIG. 6) is a thermally broken extrusion including an interior portion 232, an exterior portion 234, and a thermal break 236 interposed therebetween. The interior portion 232 includes a generally rectangularly shaped body 238 and an elongated planar inner wall 240. The rectangular body 238 includes an integral screw channel 241, an integral thermal-break channel 242, and an integral bolt-head channel 244. Apertures 246 are provided within the floor of the bolt channel at spaced locations and apertures 248 are aligned therewith. The interior wall 240 extends beyond the width of the rectangular body 238 in both directions.
The exterior portion 234 (FIG. 6) is a generally planar member including an integral thermal-break channel 250. The inner wall 240 and the outer wall 249 are spaced one from the other to closely receive the male side frame member 36 of the panel assembly 16. The thermal break 236 intersecures the interior and exterior portions 232 and 234. Specifically, the thermal break fills both thermal- break channels 242 and 250 to space the two portions one from the other.
The left wall rail 230 (FIG. 6) is secured to the existing building structure 12 using a plurality, and preferably three, of lag bolts 252. The bolt heads 254 are recessed within the bolt-head channel 244 so that the male side frame member 36 of the window panel 16 ca abut the rectangular body 238 of the left wall rail.
Similarly, the right wall rail 260 (FIG. 7) provides a means for mounting a female side frame member 34 to the existing building structure. The right wall rail 260 is a thermally broken extrusion including an interior portion 262, an exterior portion 264, and a thermal break 266. The interior portion 262 is generally rectangular in cross section defining an integral screw channel 267, an integral bulb-seal channel 268, and an integral bolt-head channel 270. Apertures 272 are provided in the floor of the bolt-head channel 272 at spaced locations, and apertures 274 are aligned therewith permitting a plurality of, and preferably three, bolts to extend through the rectangular body. The interior portion 262 also defines an integral thermal-break channel 275 for receiving the thermal break material. A C-shaped flange 278 extends from one corner of the rectangular body 267 to provide a reference surface with the female side frame member 34.
The exterior portion 26 (FIG. 7) is generally planar and includes an outwardly opening integral bulb-seal channel 276 and an inwardly facing integral thermal-break channel 278. A thermal break 266 intersecures the interior and exterior portions 262 and 264. Specifically, the thermal break 266 fills both thermal break channels 27 and 278 to space the two portions one from the other. The outside distance between bulb seal channels 268 and 276 is dimensioned so that the female side frame member 34 can fit closely thereover. Conventional bulb seals are mounted within the channels 268 and 276 to be compressed by the female side frame member 34 to provide a weather-tight seal therebetween. Consequently, the female edge portion of one window assembly 16 can be connected to the existing building 12 without the necessity of a special panel. Such construction permits all modular panels to remain identical to one another.
V. Slidinq Door
The sliding door assembly 279 (FIGS. 1, 2, and 8) is a conventional 583/8"×791/2" sliding door unit with a modified frame to interfit with the modular window panels 16. The slider 279 has a width twice that of one of the window panels 16; and the slider can therefore be substituted for any two window panels. FIG. 8 is a horizontal cross-sectional view through the sliding door frame, which includes a conventional left side member 290 and a conventional right side member 292 which are mirror images of each other. Such slider doors and frames are well known to those having ordinary skill in the art.
The female door post or adapter 294 (FIG. 8) is attached to the right frame member 292 to interfit with the male edge member 34 of a window panel assembly 16. The female frame adapter 292 is a thermally broken extrusion including an interior portion 232, an exterior portion 296, and a thermal break 298. The interior portion 232 is generally identical to the interior portion 232 illustrated in FIG. 6; and consequently a detailed description will not be again provided. Suffice it to say that the interior portion 232 includes an integral screw channel 241 and an integral thermal-break channel 242.
The exterior portion 296 includes a generally planar body 300 including an integral thermal-break channel 302 facing the channel 242. The thermal break 298 intersecures the inner and outer portions 232 and 296. Specifically, the thermal break 298 fills both channels 242 and 302 to space the portions one from the other. A plurality of, and preferably six, apertures 304 aligned with the screw channel 241 are drilled into the interior extrusion 232 to receive flat-head Phillips screws 306 to secure the left slider frame member 292 to the adaptor 294. The adaptor 294 defines a female channel 308 dimensioned to closely receive a male side frame member 36 of a window panel assembly 16. Alternately, the channel 308 could directly interconnect with a corner post 18 (FIG. 5) or the left wall rail 230 (FIG. 6).
Similarly, the male door post or frame adapter 310 (FIG. 8) permits the left slider frame member 290 to interfit with a female side frame member 32 of a window panel assembly 16. The adapter 310 is also a thermally broken extrusion including an interior portion 262 and an exterior portion 264 interconnected by a thermal break material 312. The interior and exterior portions 262 and 264 are generally identical to those illustrated in FIG. 7 and will therefore not be described in detail. Suffice it to say that the interior portion 262 includes an integral screw channel 267 and an integral thermal-break channel 276; and the exterior portion 264 includes an integral thermal-break channel 278. The thermal break material 312 interconnects the interior and exterior portions 262 and 264. Specifically, the thermal break material 312 fills both channels 276 and 278 to space the two portions one from the other. A plurality of, and preferably six, apertures 314 are formed in the interior portion 262 to be aligned with the screw channel 267. Flat-head Phillips screws 316 are secured within the screw channel to secure the right slider frame member 290 to the frame adapter 310. The male adapter 310 permits the left side of the slider to interfit with the female side frame member 32 of the adjacent window assembly 16. Alternately, the adapter 310 could interfit directly with a corner post 18 (FIG. 5) or the right wall rail 260 (FIG. 7).
VI. Swinq Door
FIG. 9 illustrates an alternate embodiment of the sun porch wherein a swing door unit 320 is substituted for one of the window panels 16. A horizontal cross section through the swing door unit 320 is illustrated in FIG. 10. The door unit includes a right frame assembly 322, a left frame assembly 324, and a swing door 326. The right frame assembly 322 includes a female door post or right frame adapter 294 and a right door jamb 328. The female frame adapter 294 is generally identical to that illustrated in FIG. 8; and consequently the detailed construction thereof will not be set forth again in detail. The right door jamb 328 is a thermally broken extrusion including an inner portion 330, an outer portion 332, and a thermal break 334, which interconnects the two portions and spaces them one from the other to provide thermal insulation therebetween. The right door jamb 328 integrally defines a bulb-seal channel 338 to support the bulb seal 340.
The left frame assembly 324 (FIG. 10) includes a male door post or left frame adapter 310 and a left door jamb 356. The left frame adapter 310 is generally identical to that illustrated in FIG. 8 and will not be redescribed in detail. The left door jamb 356 is also a thermally broken extrusion including an inner portion 358, an exterior portion 360, and an interconnecting thermal break 362. The inner portion 358 includes an integral left jamb 364 which in turn defines an integral bulb-seal channel 366. A bulb seal 368 is mounted within the channel 366 to provide a weather seal against the door 350. A strike plate 370 is mounted in conventional fashion on the left frame half 356 to receive the latch from the lock set (not shown) on the door 326.
The door 326 is of conventional construction including a door blank 350 and a door light 352 mounted therein. The door is swingably mounted to the right frame assembly 322 via hinges 354.
The width of the door unit 230 is generally identical to the width of one window panel 16. Consequently, the door unit 320 can be substituted for any panel 16 about the perimeter of the sun porch 10. Although the door is illustrated in FIG. 9 as being immediately adjacent the existing building 12, the location of the door 320 can be altered as desired. The left and right frame adapters 310 and 294 permit the door to interfit with the adjacent sun porch components to continue the modular construction about the perimeter of the sun porch. For example, the male adapter 310 can interfit with a female side frame member 34 (FIG. 4), the left wall rail 230 (FIG. 6), or the corner post 18 (FIG. 5). Similarly, the female adapter 294 can interfit with a male side frame member 36 (FIG. 4), the right wall rail 260 (FIG. 7), or the corner post 18 (FIG. 5).
VII. Triangles
The left triangle 20 (FIGS. 1 and 11) and the right triangle 20(FIG. 9) are mirror images of one another; and consequently only the left triangle will be described in detail. The left triangle 20 (FIG. 11) includes an upper rail assembly 380 and a lower rail assembly 382. The two rail assemblies are spaced from one another adjacent the existing building structure 12 and meet one another at the front face of the sun porch 10.
The upper rail assembly 380 (FIG. 11) is a thermally broken extrusion including a body portion 384, a top portion 386, an exterior portion 388, and a bottom portion 390. The body portion 384 is generally rectangular in cross section and defines an integral thermal-break channel 392 at its upper outer corner and an integral gasket channel 394 at its upper inner corner. The lower outer corner 396 is recessed and includes a snap flange 398.
The top portion 386 (FIG. 11) is generally C-shaped in cross section and defines an integral thermal-break channel 400 therein. The body portion 384 and the top portion 386 are interconnected by the thermal break 382. Specifically, the thermal break fills both channels 392 and 400 to space the two portions one from the other.
The exterior portion 388 (FIG. 11) is generally L-shaped in cross section including an exterior wall 404 and an upper exterior wall 406. A spacing flange 410 extends along the interior surface of the top wall 406 to engage the top portion 386. The top wall 406 terminates in a top flange 412 having a downwardly extending finger flange 414. The flanges 412 and 414 extend about the top portion 386 to secure the exterior portion 388 in position at its upper end. A spacer flange 420 extends inwardly along the lower edge of the exterior wall 404. Just above the spacing flange 420 is a glazing support 422; and just above the glazing support is a thermal-break support 424 including a thermal-break channel 426.
The bottom portion 390 (FIG. 11) includes an integral thermal-break channel 428, a flange channel 430, and a snap channel 432. A ramped surface 434 leads to the snap channel 432 to facilitate the insertion of the snap flange 398 therein. A thermal break 434 interconnects the exterior portion 388 and the bottom portion 390. Specifically, the thermal break 434 fills both channels 426 and 428 to space the two portions one from the other. A generally L-shaped retainer 436 is fitted within the channel 430 and bears against the window glass 438 to secure the glass in position. Preferably, a glazing compound (not shown) is mounted on the glazing support 422 to provide a weather seal against the glass 438. The spacing flange 420 prevents the glass 438 from engaging the glazing support 422 and also prevents squeeze-out into the viewing area.
The glass 438 is typically generally identical to the glass 30; however, any suitable panel can be used. The glass 430 is generally triangular in shape having the upper rail assembly 380 extending along its upper edge and the lower rail assembly 382 extending along its lower edge.
The bottom rail assembly 382 of the triangle 20 (FIG. 11) is adapted to support the triangle on the wall panels 16 and/or the doors possibly substituted therefor. The bottom rail assembly is a thermally broken extrusion including an interior portion 450, an exterior portion 452, and a thermal break 454 extending therebetween. The interior portion 450 is generally rectangular in cross section and includes an integral retainer channel 456 and an integral thermal-break channel 458. A bulb-seal support 460 extends downwardly and includes an integral bulb-seal channel 462.
The exterior portion 452 (FIG. 11) includes a spacing flange 464 along its upper edge and a glazing support 466 just therebelow. The exterior bulb-seal support 468 extends downwardly and includes an integral bulb-seal channel 470. The thermal-break channel 471 faces the channel 458. The thermal break 454 interconnects the interior and exterior portions 450 and 452. Specifically, the thermal break fills both channels 458 and 471 to space the portions one from the other. An L-shaped retainer 472 fits within the retainer channel 456 and bears against the glass 438. A glazing compound (not shown) is carried by the glazing support 466 to provide a weather seal against the window glass 438. The bulb channels 462 and 470 closely receive therebetween the window panels 16 in male/female fashion.
VIII. Roof Assemblv
FIGS. 12-15 illustrate the construction of the roof assembly 22 (see also FIG. 1). The roof assembly includes a top cap assembly 480, a building beam assembly 482, a plurality of rafters 484 (FIGS. 12 and 13) a plurality of purlins 486 (FIGS. 14 and 15), a plurality of roof panels 488, and a plurality of retainers 490 (FIGS. 11 and 13).
The front cap assembly 480 (FIG. 15) is a thermally broken extrusion including a plurality of extruded portions. The top cap assembly 480 defines a bottom channel 492 including a pair of inwardly facing bulb-seal channels 494 and 496. The channel 492 fits over the top portion of the wall channels 16 in male/female fashion. Additionally, the top cap assembly 480 includes an exterior portion 498 and an interior portion 500. A plurality of shoulder screws 502 are secured within the interior portion 500 to support the rafters as will be described. A resiliently compressible gasket 504 is mounted on the upper portion of the interior portion 500 within the channel 505 to support a roof panel 488 also as will be described Thermal breaks 506 and 508 are provided within the top cap assembly to thermally insulate the interior portion of the top cap from the exterior portion.
The wall plate or building beam 482 (FIG. 15 supports the roof assembly 22 on the existing building structure. The building beam 482 includes a body extrusion 510 which is generally quadrilateral in cross section and defines an opening 512 along its length. Lag bolts 514 or other suitable fasteners are utilized to secure the building beam assembly 482 to the existing building structure. The access opening 512 provides access to the lag bolts 514. An elongated cap 516 is snap-fitted within the opening 512 to cover the access opening subsequent to securement of all lag bolts 514. The body portion 510 includes an interior wall 517 which includes an integral screw channel 518 on the underside thereof. A plurality of shoulder screws 520 are secured at spaced locations within the screw channel 518 along the length of the building rail 510 to support the rafters 484 as will be described. The body portion 510 also includes a top wall 530 which defines an upwardly opening gasket channel 532, a screw channel 534, and a thermal-break channel 536. A resiliently compressible gasket 538 is mounted within the gasket channel 532 to directly engage and support the roof panel 488. The screw channel 534 receives bolts to secure the retainer 650' in position as will be described. Flashing portion 540 is secured to the body extrusion 510 via the thermal break 542.
The rafter 484 (FIGS. 12 and 13) includes an extrusion generally rectangular in cross section. The extrusion includes a top wall 550, a pair of opposite side walls 552 and 554, and a bottom wall 556. The top wall 550 defines a pair of upwardly opening gasket channels 558 and 560 along the outboard edges adjacent the side walls 552 and 554, respectively. A screw channel 562 extends upwardly from the center of the top wall 550 to receive bolts anchoring the retainers 650 in position as will be described. Resiliently compressible gaskets 564 are fitted within the channels 558 and 560 to directly engage and support the roof panels 488 and provide a weather seal thereagainst. Screw channels 566 and 568 open outwardly through the side walls 552 and 554, respectively, adjacent the bottom wall 556 to provide a means of securing accessories such as blinds or quilts to the rafters. A plurality of shoulder screws 600 are secured within the side walls 552 and 554 of the rafter 484 to support the purlins as will be described.
The rafters 484 each have a length sufficient to extend the full distance between the top cap assembly 480 and the building beam 482 (see also FIG. 15). The rafters 484 are supported on the shoulder screws 502 and 520; and to this end rafter brackets 580 (FIGS. 12 and 13) are mounted in either end of each rafter. Specifically, the rafter bracket includes a face 582, a top flange 584, and a bottom flange 586. The face 582 is oriented in a plane generally perpendicular to the axial direction of the rafter 484. The face is generally rectangular including a lower edge 588 and a tab 590 extending downwardly from the central portion of the face 582. A pair of slots 592 and 594 extend upwardly into the face 582 from the lower edge 588 and terminate in semi-spherical ends 592a and 594a, respectively. The top flange 584 is integral with and generally perpendicular to the face 582. The top flange is secured to the underside of the top wall 550 of the rafter 484 using pan-head Philip screws 596 preferably at four locations. The lower flange 586 is integral with and generally perpendicular to the tab 590 and is secured to the bottom wall 566 of the rafter 484 using rivets 598 preferably at two locations. As best seen in FIG. 13, the rafter bracket 580 is confined within the cross-sectional shape of the rafter 484.
The rafter 484 is mounted between the top cap assembly 480 and the building beam 482 by interfitting the rafter brackets 580 on the shoulder screws 502. Preferably, the slots 592 in the rafter bracket 580 are aligned with the shoulder screws 502 on the top cap assembly 480 and the bracket is slid downwardly into position. The slots 592 in the opposite end of the beam are then aligned with the shoulder screws 520 in the building beam assembly 482 and that end of the beam is also then lowered into position. The shoulder screws 502 and 520 are also within the lateral confines of the cross-sectional shape of the rafters 484, or the imaginary extension of that cross-sectional shape. Further, each rafter end abuts or is closely adjacent the top cap assembly 480 or the building beam assembly 482 to completely hide the attachment assembly. Consequently, the resultant attachment assembly is completely hidden from view.
The roof purlins 486 (FIGS. 14 and 15) extend between adjacent rafters 484 to support two adjacent roof panels 488. Each purlin includes a body extrusion 610 which is generally rectangular in cross section including a top wall 612 which defines upwardly opening gasket channels 614 and 616. A resiliently compressible gasket 632 is mounted within each of the gasket channels 614 and 616 to directly engage and support the roof panels 488 and provide a weather seal thereagainst. An integral screw channel 618 extends upwardly from the center of the top wall 612 to prevent the upper roof panel assembly 488a from sliding downwardly and perhaps over the lower roof panel assembly 488b during installation.
One purlin bracket 620 (FIGS. 14 and 15) is secured within each end of the purlin and includes a face 622 and a top flange 624. The face 622 is generally perpendicular to the longitudinal direction of the purlin body 610 and includes a lower edge 626. A pair of slots 628 extend upwardly into the face 622 from the lower edge 626 to receive the shoulder screws 600 (see also FIGS. 12 and 13). The top flange 624 is secured to the underside of the top wall 612 of the rafter extrusion 610 using pan-head Phillip screws 630.
The purlins 486 are readily and easily installed between adjacent rafters 484. Specifically, the slots 628 within the purlin brackets 620 are aligned with the shoulder screws 600 in adjacent rafters, and the purlin is lowered into position so that the bracket 620 travels downwardly about the shoulder screws to retain the purlin in position. As perhaps best illustrated in FIG. 15, the attaching structure including the bracket 620 and the shoulder screws 600 lie entirely within the lateral confines of the cross-sectional shape of the purlin 486 or its imaginary extension thereof. Further, the purlin extrusion 610 is closely adjacent the opposite rafters between which it is mounted to hide the connection assembly from view after the purlin is slid into position.
The roof panels 488 (FIGS. 11 and 15) are all preferably identical to the window glass 30 in the window panel 16 and the window glass 438 in the triangles 20. Of course, alternate transparent or translucent panels can also be used. The roof panels 488 rest directly on one gasket on each of two adjacent rafters 484 or on a triangle and the adjacent rafter. Each panel 488 also rests on one gasket of a purlin 486 and the gasket of either top cap assembly 480 or building beam 482. Because each of the resiliently compressible gaskets is continuous throughout the full length of the member on which it is mounted, an effective weather seal is provided around the entire periphery of each roof panel 488.
The lower edge 640 (FIG. 15) of the roof panels 488 is fitted within a spacer 642. The spacer includes a C-shaped portion 644 fitted about the lower edge 640 and a flange portion 646 extending therefrom and over the upper edge 648 of the lower panel 488b. The spacer 642 prevents the glass roof panel 488 from directly engaging the top cap assembly 480 or the screw boss 618 and also provides integral flashing.
One retainer assembly 650 is mounted on each rafter after the adjacent window panels supported thereon are in position. The retainer assembly 650 includes a retainer extrusion 652 defining a bolt-head channel 654 extending downwardly from the inner surface and also a pair of downwardly opening gasket channels 656 and 658. Resiliently compressible gaskets 660 are fitted within the gasket channel 656 and 658 to engage the roof panels 488 and provide a weather seal thereagainst. The bolt-head channel 654 includes a floor 662 having apertures 664 at spaced locations therealong. Hex head bolts 666 extend through the channel floor 662 and into the screw boss 562 to secure the retainers in position. A retainer cap 668 is snap-fitted within the bolt-head channel 654 after all bolts 66 have been installed to cover the bolt heads and provide an aesthetically pleasing appearance. A retainer assembly 650' (FIG. 15) of identical construction is used to secure the upper roof panels 488a against the building beam assembly 482.
IX. Installation Summarv
The sun porch 10 is easily and readily assembled onto an existing building 12. Preparation begins by pouring a concrete pad 11 of suitable depth, preferably four inches, and having a suitable footing thereabout. Preferably, prior to the setting of the concrete, the anchor bolts 116 (FIG. 3) are set within the concrete.
After the concrete has set, the base assembly 14 is secured to and leveled on the pad 11 as described in conjunction with the description of FIGS. 3A and 3B. The wall rails 230 and 260 and the top beam 482 are then secured to the existing building 12; and the first window panel 16 is interfitted therewith. Specifically, the female side frame member 34 of the window assembly 16 is interfitted over the male portion of the right wall rail. The second window panel assembly is then interconnected with the first window assembly in similar male/female relationship. Installation of the window panels continues until the corner is reached. At that point, a corner post 18 (FIG. 5) is placed into position and interfitted in male/female relationship with the adjacent wall panel 16.
Assembly of the remainder of the wall continues in sequential fashion until all of the modular components are in position. Finally the left building rail (FIG. 6) is secured to the existing building 12 so that the last wall panel 16 can be placed into position.
After all walls have been erected, the triangles 20 and the top cap assembly 480 (FIG. 15) are mounted over the wall panels 16 and any slider or door mounted therein. The tie rods 207 are anchored within the base assembly 14, extend through the corner post 18, and are secured against the top cap assembly 480. The undersides of the triangles and top cap fit in male/female relationship with the upper edge of the wall panels.
The rafters 484 (FIGS. 12 and 13) are then mounted between the top cap assembly 480 and the building beam 482 by sliding the rafters downwardly into position over the shoulder screws 502 and 520. The purlins 486 (FIGS. 14 and 15) are then installed between the rafters by sliding their brackets over the shoulder screws 600 secured in the rafters.
The roof panels 488 are then placed in position. Preferably, each lower panel is placed in position prior to the associated upper panel. Finally, the retainer assemblies 650 and 650' (FIGS. 13 and 15) are installed to secure the roof panels against the rafters 484 and the building beam assembly 482.
The modular door assemblies 279 and 320 can be substituted for one or more of the window panel assemblies at any position about the perimeter of the sun porch. Specifically, the slider unit 279 can be substituted for any two adjacent window panel assemblies 16; and the swinging door unit 320 can be substituted for any single window panel assembly 16. Because of the unique male/female configuration of the slider and swinging door frames, these units can easily interfit with the existing male/female scheme.
Thus, it is seen that the sun porch can be readily and easily assembled by home owners or other "do-it-yourselfers⃡ having relatively limited carpentry or construction skills. Further, the sun porch can be assembled extremely easily by one having the described skills to reduce assembly time and thus the ultimate cost of the assembled sun porch 10.
The above description is that of a preferred aspect of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention which are defined in the appended claims, which are to be interpreted in accordance with the principles of patent law, including the doctrine of equivalents.
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The specification discloses a modular sun porch which can be easily and quickly assembled. The wall assembly includes a plurality of identical modular window panels whose lateral edges interfit in male/female relationship to provide weather seals therebetween. Modular door units, which have a width equal to one or more window panels, can be substituted for the window panels in the wall assembly and include frames which interfit with the male/female scheme. The base for the wall assembly is levelable and hides both the base tie-downs and the leveling mechanism. The roof includes rafters and purlins which slide-lock into position between beams and rafters, respectively. Roof panels rest on gaskets carried by the rafters and purlins, and retainers are secured to the rafters to retain the panels in position and to improve the weather seal.
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] This invention relates to the field of soil erosion control. More specifically, the invention comprises a new method of manufacturing and packing sections of silt fence.
[0006] 2. Description of the Related Art
[0007] Soil erosion is a constant problem in construction work, where the bare soil must often be left exposed to rain for considerable periods. Traditionally, hay bails were staked to the ground in order to slow water run-off down bare slopes. While effective, this technique was labor intensive and had inherent shipping and storage problems—owing to the weight of the bales. The more modem approach is to use silt fencing.
[0008] A silt fence is a porous barrier fabric which is attached to and stretched between a number of stakes. The stakes are driven into the ground in positions needed to stretch the fabric across the anticipated direction of water flow. The fabric is designed to allow the passage of water, but to encourage the deposition of any sediment being carried in the water. The result is that sediment builds up on the upstream side of the fabric, with the silt fence ultimately tending to bury itself.
[0009] Numerous prior art patents pertain to silt fences and methods of producing and installing them. These prior art patent include U.S. Pat. Nos. 6,158,923, 6,053,665, 5,944,114, 5,921,709, 5,915,878, 5,622,448, 5,345,741, and 4,756,511.
[0010] [0010]FIG. 1 illustrates a typical prior art silt fence. A plurality of evenly spaced stakes 12 are provided. Silt fabric 10 is placed over stakes 12 , then affixed to stakes 12 by staples or other fastening means. The user places the fence in position by driving points 16 of stakes 12 into the ground, with the lower portion of silt fabric 10 being buried in a shallow trench.
[0011] While FIG. 1 illustrates the components of a silt fence, it does not accurately reflect how such fences are typically manufactured. FIG. 2 shows roll 28 , which is formed by a plurality of stakes 12 attached to silt fabric 10 . A silt fence is typically made by chucking center stake 36 in a rotating carriage, then attaching the starting end of silt fabric 10 to it. Center stake 36 is then rotated to wind silt fabric 10 around itself. At fixed intervals, another stake 12 is brought in and stapled to silt fabric 10 . The winding continues until a complete roll 28 is formed. It is then taped, tied, or banded to lock it in position for transportation and storage.
[0012] [0012]FIG. 2 illustrates roll 28 having eight stakes 12 . Roll 28 can be made larger or smaller. Those skilled in the art will realize that the prior art manufacturing process described is an intermittent one; i.e., once a roll is formed, the process is stopped to remove that roll and start forming a new one. This represents a disadvantage, in that it limits the speed of production. It also causes problems with any printing performed on silt fabric 10 . Many purchasers want to have their names and logos printed on the silt fabric itself The best printing methods for this purpose are those using a wet printing plate. The printing dyes employed are dissolved in a liquid carrier, which must be quite volatile (in order for the printing to dry rapidly). Thus, the wet printing process is very sensitive to any pauses in the production. If the feed of silt fabric 10 is halted for significant periods, the dye solutions will dry on the printing plate and the print quality will deteriorate. The prior art intermittent production process therefore compromises printing quality on silt fabric 10 .
[0013] The roll method has two additional drawbacks. First, rolls 28 do not stack efficiently, since their circular cross section inherently produces wasted space. Second, roll 28 is cumbersome to install. Those skilled in the art will realize that roll 28 —as illustrated in FIG. 2—is modestly sized. Often these rolls will be 100 feet long. A typical installation would be in the range of 100 feet to 10,000 feet long. It is very cumbersome to unroll many hundreds of feet of silt fencing packaged in the roll form.
[0014] It is also fairly common to need a length which is less than the entire roll. In such a case, the user must lift roll 28 by its ends and unroll the needed amount. The user then cuts the needed amount free from the rest of the roll. As roll 28 can be heavy, this approach often means that two people are needed.
[0015] Alternatively, the user can unroll roll 28 by rolling it along the ground until the needed amount is laid flat. The user then removes the needed amount and re-rolls roll 28 . This approach requires the user to lift a heavy object (roll 28 ) off the back of a truck, perform the operation, and then lift it back on to the truck.
[0016] Accordingly, the prior art methods of packing silt fencing are limited in that they:
[0017] 1. Typically require an intermittent manufacturing process, thereby limiting production speed and compromising print quality;
[0018] 2. Do not lend themselves to efficient packing; and
[0019] 3. Render the silt fence cumbersome to deploy.
BRIEF SUMMARY OF THE INVENTION
[0020] The present invention eliminates the disadvantages inherent in the prior art by placing the silt fence in a flat-pack configuration. With reference to FIG. 4, stakes 12 are evenly spaced and silt fabric 10 is evenly draped over them by any suitable means to form a series of loops 14 . Silt fabric 10 is then attached to each stake 12 at the point where it drapes over each stake 12 .
[0021] Stakes 12 are then moved closer to each other as shown in FIG. 6, with the result that loops 14 grow longer and more narrow. FIG. 7 shows stakes 12 bunched tightly together, with the result that loops 14 are now very long and very narrow. As stakes 12 are held in position, loops 14 are then wrapped around stakes 12 as indicated by the arrow.
[0022] [0022]FIG. 8 shows stakes 12 —still being held in position—with loops 14 wrapped around them. In FIG. 9, securing straps 24 have been placed around the assembly to create flat pack 26 . This entire process can be carried out on a linear assembly line without intermittently stopping the motion.
[0023] The objects and advantages of the present invention are:
[0024] 1. To provide an improved method of packing and storing silt fence which can be carried out on a linear assembly line without intermittently stopping the linear motion;
[0025] 2. To provide an improved method of packing and storing silt fence which does not waste storage space; and
[0026] 3. To provide an improved method of packing and storing silt fence which enables the user to easily pull off a short section of silt fence without having to lift the entire pack.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0027] [0027]FIG. 1 is an isometric view, showing a completed silt fence.
[0028] [0028]FIG. 2 is an isometric view, showing the prior art method.
[0029] [0029]FIG. 3 is an isometric view, showing the manufacture of the present invention.
[0030] [0030]FIG. 4 is an isometric view, showing the manufacture of the present invention.
[0031] [0031]FIG. 5 is an isometric view, showing the addition of staples.
[0032] [0032]FIG. 6 is an isometric view, showing the bunching of the loops.
[0033] [0033]FIG. 7 is an isometric view, showing the completion of the bunching of the loops.
[0034] [0034]FIG. 8 is an isometric view, showing the wrapping of the loops around the stakes.
[0035] [0035]FIG. 9 is an isometric view, showing the strapping of the flat pack.
REFERENCE NUMERALS IN THE DRAWINGS
[0036] [0036] 10 silt fabric
[0037] [0037] 12 stake
[0038] [0038] 14 loop
[0039] [0039] 16 staple
[0040] [0040] 18 stake top
[0041] [0041] 20 starting color patch
[0042] [0042] 22 ending color patch
[0043] [0043] 24 securing strap
[0044] [0044] 26 flat pack
[0045] [0045] 28 roll
[0046] [0046] 30 point
[0047] [0047] 32 first stake
[0048] [0048] 34 last stake
[0049] [0049] 36 center stake
DETAILED DESCRIPTION OF THE INVENTION
[0050] [0050]FIG. 3 illustrates the major components involved in the process. A plurality of stakes 12 are evenly spaced along a production line by any conventional means. A strip of silt fabric 10 is then fed to the top of the plurality of stakes 12 . The illustration simply shows a long ribbon of silt fabric 10 being draped over stakes 12 . This can also be accomplished by a linear feed of silt fabric 10 (such as off a large master roll) descending down over a line of moving stakes 12 . In the example shown in FIG. 3, an assembly line could move stakes 12 from right to left in the view, as the ribbon of silt fabric 10 is deposited over their tops.
[0051] [0051]FIG. 4 shows silt fabric 10 laid evenly over stakes 12 . However this operation is carried out, significant result is that silt fabric 10 must be placed so as to create a plurality of even loops 14 between stakes 12 . The loops need not be exactly alike, but it is important to have them approximately equal in length.
[0052] While stakes 12 and silt fabric 10 are in the relationship shown in FIG. 4, silt fabric 10 must be attached to stakes 12 . FIG. 5—a detail view—shows the addition of stapes 16 . Two or more staples 16 are driven through each portion of silt fabric 10 that lies on top of a stake 12 . Once staples 16 are in place, the length of each loop 14 is fixed.
[0053] The reader should appreciate that while staples are particularly effective from a strength and cost standpoint, many other types of fasteners could be used. These would include nails, screws, adhesives, stitching, slats, tie cords, and the like.
[0054] The next step in the manufacturing process is shown in FIG. 6. After staples 16 are in place, stakes 12 are pushed closer together—as shown by the arrow. The result is that loops 14 begin to lengthen and become more narrow. This process continues until stakes 12 are bunched closely together in a single plane, as shown in FIG. 7. The reader will note that loops 14 are by this point long and narrow. It is advantageous to use gravity to orient loops 14 by allowing them to descend below the production line during this process. However, the use of gravity is not the only way to accomplish this. A set of guiding rods placed through each loop 14 could be used to pull them in any direction desired. Many other conventional mechanisms could be employed.
[0055] Once the bunching of stakes 12 is complete, the plurality of loops 14 is wrapped around stakes 12 in the direction indicated by the arrow. Stakes 12 are held in position as loops 14 are wrapped snugly around them. This wrapping process serves to pull stakes 12 even closer together.
[0056] [0056]FIG. 8 shows stakes 12 with the plurality of loops 14 wrapped tightly around them. The reader will observe that each loop 14 has been pressed flat. As silt fabric 10 is thin and highly flexible, this operation does not place undue stress on the fabric.
[0057] The assembly shown in FIG. 8 will not remain in its compact state without an additional step. FIG. 9 shows the addition of two securing straps 24 . These can be metal bands, plastic bands, tape, or the like. Their function is to tightly bind the components together. Once bound, the result is a unitary structure referred to as flat pack 26 . Flat pack 26 can be handled as a unit. Many flat packs 26 can be vertically stacked with very little waste of space. Flat packs 26 can also be placed on their narrow edges and stored in that fashion with very little waste of space.
[0058] The reader should appreciate that although stakes 12 have been illustrated as square, the method can be employed for stakes having many different cross-sections and characteristics.
[0059] When a user wants to pull the silt fence out of flat pack 26 , it is important to know which end to start from. The user first removes securing straps 24 . The user then pulls the portions of loops 14 resting over the top of flat pack 26 off to the left in FIG. 9. The user then pulls first stake 32 off to the left. The user then continues moving first stake 32 to the left. This action results in each successive loop 14 being unfurled out into a tight sheet and pulling the next stake 12 out of flatpack 26 .
[0060] Those skilled in the art will realize that flat pack 26 can be made with many more stakes 12 than are shown in FIG. 9. In such a case, the user may not wish to use all of the flat pack. If so, the user simply stops pulling at the desired point and makes a transverse cut across silt fabric 10 . He or she is able to pull off any desired amount without having to lift or move flat pack 26 .
[0061] So long as the user starts with first stake 32 , the unpacking operation will be smooth. Those skilled in the art will realize, however, that if the user starts pulling with last stake 34 (pulling it to the right as shown in FIG. 9), the operation will not be smooth. If the user begins pulling with last stake 34 , he will have to pull the loops under flat pack 26 in order to start pulling last stake 34 free. This is difficult without moving the whole flat pack 26 . The goal is to have flat pack 26 remain stationary while the user pulls off the desired length of silt fencing. Thus, it is important to be sure the user starts pulling on the correct end.
[0062] It is also important to ensure that flat pack is oriented as shown in FIG. 9; i.e., with the ends of loops 14 on its upper surface. If it is inverted, then the user will have difficulty pulling loops 14 out from beneath flat pack 26 .
[0063] To ensure these goals, a color designation system is employed. First stake 32 has starting color patch 20 on its upper surface at its upper end (nearest the viewer in FIG. 9). Likewise, last stake 34 has ending color patch on its upper surface at its upper end. The colors employed should be easily distinguished—such as blue and yellow. These color cues will assist persons stacking flat packs 26 . As an example, when placed on a truck, flat packs 26 should be placed with the color patches facing upward, and with first stake 32 toward the rear of the truck (or toward whichever side the silt fencing will be unloaded from).
[0064] The manufacturing operations described in FIGS. 3 through 9 could be carried out using a variety of mechanisms. The actual mechanisms employed are not significant to the present invention. However, it is important for the reader to understand that all of these operations can be carried out while stakes 12 are moving down a linear assembly line. In FIGS. 3 and 4, silt fabric 10 can be properly fed onto the plurality of stakes 12 as stakes 12 move transversely down an assembly line (with the stakes moving from right to left as shown in FIG. 4). Staples 16 can also be added while the line continues to move.
[0065] The bunching operations described in FIGS. 6 and 7 can be accomplished by transferring stakes 12 onto a decelerating conveyor. A desired length of silt fencing is then cut free and the wrapping of loops 14 (FIGS. 7 and 8) can be performed. There is no need to stop and start the moving assembly line, as in the prior art rolling approach.
[0066] Accordingly, the reader will appreciate that the proposed invention can readily create a silt fence stored in a convenient flat pack. The invention has further advantages in that it:
[0067] 1. Can be carried out on a linear assembly line without intermittently stopping the linear motion;
[0068] 2. Provides an improved method of packing and storing silt fence which does not waste storage space;
[0069] 3. Enables the user to easily pull off a short section of silt fence without having to lift the entire pack; and
[0070] 4. Enables the user to easily inventory a stack of silt fencing since the flat pack has little wasted space.
[0071] Although the preceding description contains significant detail, it should not be construed as limiting the scope of the invention but rather as providing illustrations of the preferred embodiment of the invention. As an example, many different methods could be employed to attach silt fabric 10 to stakes 12 . As another example, mechanisms could be employed to align loops 14 in a single orientation, rather than using gravity to align them by suspending them below stakes 12 . Thus, the scope of the invention should be fixed by the following claims, rather than by the examples given.
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A method for packaging conventional silt fencing and a product produced by the method Silt fabric is attached to a number of evenly spaced stakes. The stakes are then bunched together so that the silt fabric hangs between the stakes in descending loops. The bunching is continued until all the stakes lie close together in one plane. The loops of silt fabric are then wrapped tightly around the stakes. Securing bands are then placed around the assembly to create a flat pack.
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BACKGROUND OF THE INVENTION
This invention relates to high frequency antenna systems and more specifically to wideband feeds for use in such antenna systems.
U.S. Pat. No. 4,042,935, entitled "Wideband Multiplexing Antenna Feed Employing Cavity Backed Wing Dipoles," by J. S. Ajioka and G. I. Tsuda, and assigned to a common assignee with this application, describes a nested cup dipole feed for a circularly polarized antenna. The feed covers multiple octave bands. Between each octave, or at the crossover points in frequency, the gain or sensitivity drops by about 7 dB. As represented in FIG. 2 of this patent, the outer four printed circuit elements cover an octave band. A diagonal pair is fed by a balun to provide linear polarization. The orthogonal pair is also fed by a balun to provide orthogonal linear polarization. For the circular polarized application, the two orthogonal linearly polarized dipoles are fed by a 90 degree hybrid. Another set of four elements placed 45 degrees with respect to the first set covers the second octave band. The third set of four is again placed 45 degrees with respect to the second set but is colinear with the first set. The elements for each band are positioned 45 degrees from their respective adjacent bands. When the feed is used with a parabolodial reflector with a focal distance to diameter ratio of between 0.3 to 0.45, the average efficiency ranges from 40% to 50%. At the band or frequency crossover, the efficiency drops to about 10%.
The applicability of nested cup dipole feed of U.S. Pat. No. 4,042,935 could be increased if the polarization can be made collinear. For instance, the feed of U.S. Pat. No. 4,042,935 cannot be used for an offset reflector because the dipoles for all bands cannot be aligned radially or circumferentially for all bands. If the dipoles (polarization) are not aligned properly, the asymmetry created by the offset reflector causes depolarization which results in coupling between both dipoles. This causes the efficiency to degrade and the beam to squint as a function of frequency and polarization. Another advantage of collinear arrangement is that there are many cases where vertical and horizontal polarization (in space) are required rather than slant 45 degrees. Other applications may require collinear dipoles with staggered crossover tuning. By tuning one dipole differently with respect to the orthogonal ones, a large efficiency decrease can be avoided for at least one linear polarization at the crossover frequencies. In other words, frequency staggering can be accomplished.
There are many applications requiring that the polarization from one band to another be aligned; that is, all vertical and all horizontal.
It is therefore an object of the present invention to provide a nested cup dipole feed which provides collinear polarization for all bands.
A further object is to provide a nested cup dipole feed which enables frequency staggering of one linear polarization with respect to the orthogonal linear polarization if required, thus permitting at least high gain for one polarization.
SUMMARY OF THE INVENTION
These and other objects and advantages are achieved by a nested cup dipole antenna feed system in accordance with the invention, which comprises a plurality of coaxially disposed conductive cylinders of progressively larger diameters disposed about a common axis. The conductive members are closed at one end thereof to define a plurality of nested annular cavities with common walls therebetween. The open ends of the cavities are in substantial transverse alignment. At least one pair of dipole elements is disposed adjacent the open ends of each of the cavities and electromagnetically coupled thereto. Means are provided for coupling electromagnetic energy between the dipole of elements of each pair. This provides an antenna feed system operating at multiple frequency bands, i.e., one band per cavity.
In accordance with the invention, the respective dipole elements are disposed in a collinear arrangement in relation to corresponding dipole elements for adjacent cavities. To provide a dual polarization feed system, two pairs of dipole elements are disposed adjacent the open ends of each of the cavities, wherein each of the pairs is orthogonal to the other. The collinear placement of the dipole elements for all bands makes one linearly polarized set to be orthogonal to the other collinear set. This arrangement permits consistent polarization throughout the bands. By making one collinear set of dipole elements for a given cavity larger in size than the other set of dipole elements, frequency staggering at the crossover frequencies can be provided.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the present invention will become more apparent from the following detailed description of an exemplary embodiment thereof, as illustrated in the accompanying drawings, in which:
FIG. 1 is a partially exploded perspective view of a preferred embodiment of the present invention.
FIG. 2 is a plan view of the embodiment of FIG. 1.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2.
FIGS. 5 and 6 illustrate the crossed dipole pair exciting the innermost cavity of the feed system of claim 1.
FIG. 7 is a plot of amplitude versus frequency for an antenna feed system employing the invention and providing the capability of frequency staggering.
FIG. 8 is a plot of efficiency versus frequency for an antenna feed system in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A nested cup dipole feed 50 in accordance with the invention is illustrated in FIG. 1. This exemplary embodiment comprises five nested cavities 52-56 capable of covering five octave frequency bands. The cavities are defined by nested cylinders 81-84 and groundplane elements 85-89 (FIG. 3), all fabricated of an electrically conductive material.
Coaxial cables soldered in-line provide the means of exciting four dipole elements per cavity which are collinear between each of the five cavities shown. Thus, cables 61-64 provide a means of exciting the dipole elements for cavity 52, cables 65-68 provide a means for exciting the dipole elements for cavity 53, cables 70-73 provide a means for exciting the dipole elements for cavity 54, cables 75-78 provide a means for exciting the dipole elements for cavity 55, and cables 79A-79D (FIG. 5) provide a means for exciting the dipole elements 131-134 for cavity 56. The dipole elements for cavity 56 comprise a crossed dipole pair. For each polarization sense the two opposite cables are joined with a 180 degree hybrid. A larger or smaller number of octave bands are attainable with the nested cup dipole feed, depending on the application.
As shown in FIG. 1 and in greater detail in FIG. 2, an etched dipole board 60 is mounted on the front face of the nested cup dipole feed 50. The board 60 comprises a substrate of low loss dielectric material with a pattern of conductive dipole elements defined thereon, e.g., by etching a conductive layer to selectively remove the conductive material and define the dipole elements. Each of the octave bands has four dipole elements which are all collinear with each other. Thus, dipole elements 91-94 are for exciting cavity 52, elements 101-104 are for exciting cavity 53, dipole elements 111-114 are for exciting cavity 54, dipole elements 121-124 are for exciting cavity 55. Crossed dipole elements 131-134 are for exciting the cavity 56.
Compared to the feed of U.S. Pat. No. 4,042,935, intermediate dipole elements are not at a 45 degree angle, but rather are collinear, i.e., aligned along a common axis. Thus, for example, dipole elements 91 and 92 are aligned with the dipole elements 101 and 102 for the adjacent frequency band, instead of at a 45° angle as in the feed of U.S. Pat. No. 4,042,935.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2, and illustrates the nested cup structure of the feed system in further detail.
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 2, and illustrates the connection of the coaxial cables to the dipole elements.
The dipole configuration has a staggered crossover capability because one collinear set of dipole elements is physically larger in dimension than the others. For example, elements 93 and 94 are larger than elements 91 and 92 for cavity 52. The larger elements resonate at lower frequency than the smaller elements, thus providing frequency staggering.
FIG. 5 illustrates the crossed dipole pair which excites the innermost cavity 56. The dipole pair comprises dipole elements 131-134 fed respectively by coaxial cables 79A, 79B, 79C and 79D. To illustrate the manner in which the respective dipole pairs comprising the feed system of FIG. 1 are fed, FIG. 6 shows the dipole elements 131 and 133 comprising one of the dipole element pairs exciting cavity 56. A coaxial cable 136 is connected to the input port of a balun circuit 135; the two outputs of the balun circuit 135 are connected to the cables 79A and 79C. The balun circuit 135 provides the function of dividing the power of the signal provided by cable 136 between the two output ports of the balun, and providing a 180 degree difference in phase between the divided signals at the output ports. Thus, the balun circuit 135 can comprise, for example, a 180 degree hybrid network, or simply a power divider network with one of cables 79A and 79C being longer than the other by an electrical length sufficient to provide a 180 degree phase delay.
FIG. 7 illustrates the staggered crossover capability of the antenna feed system of FIG. 1. FIG. 7 includes a plot of antenna feed amplitude versus frequency for three adjacent bands. In this example, band 1 is between frequency F and 2F, band 2 is between 2F and 4F, and band 3 is between 4F and 8F. FIG. 7 also includes a simple depiction of a collinear nested cup dipole feed system 200 in accordance with the invention. Dipole elements 206 and 208 are excited to provide the amplitude pattern 205 in band 1. Dipole elements 202 and 204, disposed adjacent the same cavity as elements 206 and 208 but in the orthogonal sense, are somewhat smaller in size than elements 206 and 208, and their resulting amplitude pattern 209 is staggered or offset from pattern 205. Similarly, for the next adjacent cavity, dipole elements 216 and 218 provide the pattern 215, and orthogonal, smaller sized elements 212 and 214 provide the staggered, offset pattern 219. For the inner cavity of the feed system, elements 224 and 226 provide pattern 223, and orthogonal, smaller sized elements 220 and 222 provide the staggered, offset pattern 227.
A feed system embodying the invention was mounted at the focal point of a 10-foot diameter parabolic reflector, and swept gain measurements were taken. A plot of antenna gain, expressed in terms of efficiency versus frequency, is shown in FIG. 8 for the second lowest octave band feed cavity plus portions of the bands of the two adjacent octave cavities. Curves A, C, and E in the figure represent the efficiency performance for collinearly polarized dipole elements of the three lowest octave cavities, while curves B, D, and F are for the orthogonally polarized dipole elements. The lower crossover frequencies are seen to be staggered about 7.0 percent, while the upper crossover frequencies are staggered about 8.5 percent. The ability of such a feed to capture energy for at least one linear polarization has increased, as seen by the crossover points of curves B and C and curves D and E. The crossover levels are about 11 percent for a nested cup dipole feed as described in U.S. Pat. No. 4,042,935. The data of FIG. 8 is for a feed having staggered crossover frequencies; however, if crossover staggering is not desired for an application, both the collinear gain responses would be similar to curves A, C, and E. The average in-band efficiency for this embodiment is 47 percent.
It will be understood that, while the operation of the feed system has been described in some respects in terms of transmit operation, the feed system is capable of reciprocal transmit and receive operations.
It is understood that the above-described embodiments are merely illustrative of the possible specific embodiments which may represent principles of the present invention. Other arrangements may readily be devised in accordance with these principles by those skilled in the art without departing from the scope and spirit of the invention.
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A nested cup dipole feed capable of collinear polarization for all bands, and frequency staggering of one linear polarization with respect to the orthogonal linear polarization. The dipole elements for all bands are collinearly placed, making one linearly polarized set to be orthogonal to the other collinear sets. One collinearly placed dipole can be tuned differently from the orthogonal ones to permit frequency staggering at the crossover frequencies, thus permitting at least high gain for one polarization.
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REFERENCE TO RELATED APPLICATIONS
Reference is made to U.S. Provisional Patent Application Ser. No. 61/252,265, filed Oct. 16, 2009 and entitled “DYNAMIC ANAEROBIC AEROBIC (DANA) REACTOR” and U.S. Provisional Patent Application Ser. No. 61/366,576, filed Jul. 22, 2010 and entitled “UTILIZATION OF BIOMASS CARRIERS IN ANAEROBIC REACTORS”, the disclosures of which are hereby incorporated by reference and priority of which are hereby claimed pursuant to 37 CFR 1.78(a) (4) and (5) (i).
Reference is also made to the following patents and patent applications, owned by assignee, the disclosures of which are hereby incorporated by reference:
U.S. Published Patent Application No. 2009/0211972;
European Published Patent Application Nos. 1401775 and 2049443; and
PCT Published Patent Application No. WO 2009/10718.
FIELD OF THE INVENTION
The present invention relates to water treatment generally and more particularly to waste water treatment.
BACKGROUND OF THE INVENTION
The following publications are believed to represent the current state of the art:
U.S. Pat. Nos.: 3,168,465; 4,632,758; 4,780,198; 4,919,815; 5,196,111; 5,578,214; 5,788,838; 5,855,785; 6,063,273; 6,623,640; 6,758,886 and 7,022,226;
European Patent No.: 0 382 340;
http://www.paques.nl/?pid=245&parentid=41, which describes the Paques BIOPAQ® UASB+ system; and
http://www.paques.nl/?pid=44&parentid=41, which describes the Paques BIOPAQ® UBOX system.
SUMMARY OF THE INVENTION
The present invention seeks to provide improved systems and methodologies for water treatment.
There is thus provided in accordance with a preferred embodiment of the present invention an anaerobic water purification system including an anaerobic water purification unit receiving water to be treated and providing an anaerobic-treated water output and biomass carriers for supporting anaerobic microorganisms in the anaerobic water purification unit. Preferably, the system also includes a gas collection volume located above the anaerobic water purification unit for collecting gas produced by the anaerobic water purification unit.
In accordance with a preferred embodiment of the present invention, the gas collection volume is located in a headspace above the anaerobic water purification unit. Additionally, the system also includes gas supply functionality for supplying gas to the anaerobic water purification unit for causing relative movement of the biomass carriers. Preferably, the gas supply functionality supplies gas received from the gas collection volume.
Preferably, the anaerobic water purification unit receives water to be treated at a location near the bottom thereof. Alternatively, the anaerobic water purification unit receives water to be treated at a location near the top thereof
There is also provided in accordance with another preferred embodiment of the present invention an anaerobic/aerobic water purification system including an anaerobic water purification subsystem receiving water to be treated and providing an anaerobic-treated water output, and an aerobic water purification subsystem, integrated with the anaerobic water purification subsystem, receiving the anaerobic-treated water output and providing an anaerobic- and aerobic-treated water output.
Preferably, the aerobic water purification subsystem is located physically above the anaerobic water purification subsystem. Additionally, the anaerobic water purification subsystem includes biomass carriers for supporting anaerobic microorganisms.
In accordance with a preferred embodiment of the present invention, the system also includes a gas collection volume located above the anaerobic water purification subsystem and below the aerobic water purification subsystem for collecting gas produced by the anaerobic water purification subsystem. Preferably, the gas collection volume is located in a headspace above the anaerobic water purification subsystem.
Preferably, pressure created by the accumulation of the gas produced by the anaerobic water purification subsystem is operative to pump the anaerobic-treated water output from the anaerobic water purification subsystem to the aerobic water purification subsystem. Additionally, the system also includes gas supply functionality for supplying gas to the anaerobic water purification subsystem for causing relative movement of the biomass carriers. Preferably, the gas supply functionality supplies gas received from the gas collection volume.
In accordance with a preferred embodiment of the present invention, the aerobic water purification subsystem includes moving bed biofilm reactor functionality. Preferably, the anaerobic water purification subsystem receives water to be treated at a location near the bottom thereof.
There is further provided in accordance with yet another preferred embodiment of the present invention an anaerobic/aerobic water purification system including an anaerobic water purification subsystem receiving water to be treated, including biomass carriers for supporting anaerobic microorganisms, and providing an anaerobic-treated water output, and an aerobic water purification subsystem, receiving the anaerobic-treated water output and providing an anaerobic- and aerobic-treated water output. Preferably, the aerobic water purification subsystem is located physically above the anaerobic water purification subsystem.
In accordance with a preferred embodiment of the present invention, the system also includes a gas collection volume located above the anaerobic water purification subsystem and below the aerobic water purification subsystem for collecting gas produced by the anaerobic water purification subsystem. Preferably, the gas collection volume is located in a headspace above the anaerobic water purification subsystem.
Preferably, pressure created by the accumulation of the gas produced by the anaerobic water purification subsystem is operative to pump the anaerobic-treated water output from the anaerobic water purification subsystem to the aerobic water purification subsystem. Additionally, the system also includes gas supply functionality for supplying gas to the anaerobic water purification subsystem for causing relative movement of the biomass carriers. Preferably, the gas supply functionality supplies gas received from the gas collection volume.
In accordance with a preferred embodiment of the present invention, the aerobic water purification subsystem includes moving bed biofilm reactor functionality. Additionally or alternatively, the aerobic water purification subsystem includes moving bed clarifying reactor functionality.
Preferably, the anaerobic water purification subsystem receives water to be treated at a location near the bottom thereof. Alternatively, the anaerobic water purification subsystem receives water to be treated at a location near the top thereof
There is yet further provided in accordance with still another preferred embodiment of the present invention an anaerobic/aerobic water purification system including an anaerobic water purification subsystem receiving water to be treated and providing an anaerobic-treated water output, an aerobic water purification subsystem, located physically above the anaerobic water purification subsystem, receiving the anaerobic-treated water output and providing an anaerobic- and aerobic-treated water output, and a gas collection volume located above the anaerobic water purification subsystem and below the aerobic water purification subsystem for collecting gas produced by the anaerobic water purification subsystem.
Preferably, the gas collection volume is located in a headspace above the anaerobic water purification subsystem. Additionally, pressure created by the accumulation of the gas produced by the anaerobic water purification subsystem is operative to pump the anaerobic-treated water output from the anaerobic water purification subsystem to the aerobic water purification subsystem.
In accordance with a preferred embodiment of the present invention, the system also includes gas supply functionality for supplying gas to the anaerobic water purification subsystem for causing relative movement of the biomass carriers. Preferably, the gas supply functionality supplies gas received from the gas collection volume.
Preferably, the aerobic water purification subsystem includes moving bed biofilm reactor functionality. Additionally, the aerobic water purification subsystem includes moving bed clarifying reactor functionality. Preferably, the anaerobic water purification subsystem receives water to be treated at a location near the bottom thereof
There is also provided in accordance with another preferred embodiment of the present invention an anaerobic/aerobic water purification method including anaerobic water purification providing an anaerobic-treated water output, and aerobic water purification, integrated with the anaerobic water purification, receiving the anaerobic-treated water output and providing an anaerobic- and aerobic-treated water output. Preferably, the anaerobic water purification utilizes biomass carriers for supporting anaerobic microorganisms.
Preferably, the method also includes collecting gas produced by the anaerobic water purification in a headspace. Additionally, the aerobic water purification includes moving bed biofilm reactor functionality. Additionally or alternatively, the aerobic water purification includes moving bed clarifying reactor functionality.
There is further provided in accordance with yet another preferred embodiment of the present invention an anaerobic/aerobic water purification method including anaerobic water purification utilizing biomass carriers for supporting anaerobic microorganisms and providing an anaerobic-treated water output, and aerobic water purification receiving the anaerobic-treated water output and providing an anaerobic- and aerobic-treated water output.
In accordance with a preferred embodiment of the present invention, pressure created by the accumulation of the gas produced by the anaerobic water purification is operative to pump the anaerobic-treated water output from the anaerobic water purification to the aerobic water purification. Preferably, the method also includes collecting gas produced by the anaerobic water purification in a headspace.
Preferably, the method also includes supplying gas to the anaerobic water purification subsystem for causing relative movement of the biomass carriers. Preferably, the supplying gas utilizes gas received from the headspace.
In accordance with a preferred embodiment of the present invention, the aerobic water purification includes moving bed biofilm reactor functionality. Additionally or alternatively, the aerobic water purification includes moving bed clarifying reactor functionality.
There is also provided in accordance with another preferred embodiment of the present invention an anaerobic/aerobic liquid purification system including an anaerobic liquid purification subsystem including an inlet for receiving liquid to be treated and an outlet providing an anaerobic-treated liquid output, and an aerobic liquid purification subsystem including an inlet for receiving the anaerobic-treated liquid output and an outlet for providing an anaerobic- and aerobic-treated liquid output, and wherein the inlet of the aerobic liquid purification subsystem is connected to the outlet of the anaerobic liquid purification subsystem.
In accordance with a preferred embodiment of the present invention, pressure in the anaerobic liquid purification subsystem is operative to pump the anaerobic-treated liquid output from the anaerobic liquid purification subsystem to the aerobic liquid purification subsystem. Preferably, the system also includes a gas collection volume located in a headspace above the anaerobic liquid purification subsystem for collecting gas produced by the anaerobic liquid purification system.
Preferably, the aerobic liquid purification subsystem is located above the anaerobic liquid purification subsystem. Additionally, the anaerobic liquid purification subsystem includes biomass carriers for supporting anaerobic microorganisms.
Preferably, the system also includes a gas supply mechanism for supplying gas to the anaerobic liquid purification subsystem. Preferably, the gas supply mechanism is connected to the gas collection volume.
In accordance with a preferred embodiment of the present invention, the aerobic liquid purification subsystem further includes moving bed biofilm reactor functionality. Additionally, the system also includes liquid recirculation functionality.
There is further provided in accordance with yet another preferred embodiment of the present invention an anaerobic/aerobic liquid purification method including anaerobic purifying of liquid in an anaerobic liquid purification subsystem provided with an anaerobic-treated liquid outlet, aerobic purifying of liquid in an aerobic liquid purification subsystem provided with an inlet for receiving the anaerobic-treated liquid, and integrating the subsystems by connecting the outlet of the anaerobic subsystem to the inlet of the aerobic subsystem.
In accordance with a preferred embodiment of the present invention, pressure in the anaerobic liquid purification subsystem is operative to pump anaerobic-treated liquid output from the anaerobic liquid purification subsystem to the aerobic liquid purification subsystem. Preferably, at least one of the anaerobic purifying and the aerobic purifying utilizes biomass carriers for supporting microorganisms.
Preferably, at least one of the aerobic liquid purification subsystem and the anaerobic liquid purification subsystem includes moving bed biofilm reactor functionality. Additionally, the method also includes supplying gas to the anaerobic liquid purification subsystem for causing relative movement of the biomass carriers. Preferably, the supplying gas utilizes gas produced in the anaerobic liquid purification subsystem.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood and appreciated from the following detailed description, taken in conjunction with the drawings in which:
FIG. 1 is a simplified, partially pictorial, partially schematic, illustration of a synergetic anaerobic/aerobic water purification system constructed and operative in accordance with a preferred embodiment of the present invention;
FIG. 2 is a simplified illustration of one embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 ;
FIG. 3 is a simplified illustration of another embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 ;
FIG. 4 is a simplified illustration of yet another embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 ;
FIG. 5 is a simplified illustration of still another embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 ; and
FIGS. 6 & 7 show experimental results of use of the system in accordance with the embodiment of FIG. 1 of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is now made to FIG. 1 , which is a simplified, partially pictorial, partially schematic, illustration of a synergetic anaerobic/aerobic water purification system constructed and operative in accordance with a preferred embodiment of the present invention. As seen in FIG. 1 , there is provided an integrated reactor, designated generally by reference numeral 10 , which includes an anaerobic water purification subsystem 12 and an aerobic water purification subsystem 14 .
Anaerobic water purification subsystem 12 comprises an upper zone 16 which includes a plurality of biomass carriers 18 , and a lower zone 20 located below upper zone 16 .
In the embodiment of FIG. 1 , anaerobic water purification subsystem 12 may be configured to operate as a Moving Bed Biofilm Reactor (MBBR) wherein biomass carriers 18 are continuously circulated. Alternatively, biomass carriers 18 are periodically circulated or vibrated. Preferably, biomass carriers 18 have a density which is lower than the density of water. Alternatively, biomass carriers have a density which is equal to or greater than the density of water.
Reactor 10 also includes a pre-acidification tank 30 wherein untreated wastewater is initially pre-acidified. This enables diluting concentrated untreated wastewater while producing influent to be introduced into reactor 10 with a constant feed load. Additionally, nitrogen, phosphorus, pH, temperature and anti-foam can be regulated in pre-acidification tank 30 if necessary.
After being pre-acidified in pre-acidification tank 30 , wastewater is pumped out of tank 30 by pump 32 , and is introduced into anaerobic water purification subsystem 12 from above by means of a plurality of nozzles 34 , positioned at the top of a gas head space 36 of anaerobic water purification subsystem 12 . Alternatively, wastewater is introduced into anaerobic water purification subsystem 12 from below, through wastewater inlet conduit 38 .
Influent is sprayed onto upper zone 16 which consists of anaerobic biomass attached to floating biomass carriers 18 . The influent flows from the top of upper zone 16 to the bottom of upper zone 16 through biomass carriers 18 . The organic matter of the influent is converted by the anaerobic biomass into biogas which remains entrapped in between biomass carriers 18 and in cavities of biomass carriers 18 .
Preferably, the release of the biogas is achieved by Mixing Gas (MG) injection. Gas is injected into lower zone 20 of anaerobic water purification subsystem 12 through gas injectors 40 . Gas bubbles then rise towards gas head space 36 above upper zone 16 . The rising bubbles disturb the consistency of biomass carriers 18 , thereby releasing biogas entrapped therein. Additionally, channeling is prevented. The released biogas rises towards gas head space 36 above upper zone 16 .
Alternatively, jets 50 can be placed in the wall of upper zone 16 , which are operative to circulate the anaerobic effluent in upper zone 16 . The circulation of the anaerobic effluent causes movement of biomass carriers 18 thereby releasing biogas entrapped therein. Additionally, channeling is prevented.
To ensure a constant level of gas in gas head space 36 , the pressure of gas collected in head space 20 is controlled by a reducing valve 52 or by a water column (not shown) at a height equal to or greater than the level of anaerobic wastewater in upper zone 16 .
The biogas produced in anaerobic water purification subsystem 12 consists primarily of methane (CH 4 ) and carbon-dioxide (CO 2 ). Due to recirculation, part of the produced CO 2 is removed, which causes an increase of the pH level of the anaerobic effluent. This reduces the reagents consumption dramatically.
Biological conversion of up to 90% of mostly organic matter is performed by the anaerobic biomass attached to floating biomass carriers 18 . To ensure efficient conversion of up to 90% of the organic matter in anaerobic water purification subsystem 12 and to facilitate attachment of anaerobic biomass to biomass carriers 18 , the flow-through rate and the hydraulic retention time (refresh rate) of the wastewater must be sufficiently high.
The immobilization of anaerobic biomass on biomass carriers 18 prevents anaerobic biomass from leaving anaerobic water purification subsystem 12 and reaching aerobic water purification subsystem 14 .
It is a particular feature of the present invention that the use of biomass carriers in anaerobic water purification subsystem 12 allows obviating the conventional three-phase separation, before biogas collection.
Preferably, circulation of wastewater within anaerobic water purification subsystem 12 is achieved by pumping wastewater from the bottom of anaerobic water purification subsystem 12 to the top of anaerobic water purification subsystem using a pump 54 , and then dispersing the circulated wastewater by diffusers or jets 50 . Alternatively, circulation of wastewater is achieved by a mechanical mixer (not shown).
Preferably, anaerobic sludge 56 (S) which accumulates at the bottom of anaerobic water purification subsystem 12 is circulated by a mechanical mixer, a circulation pump or any other circulation device. Additionally or alternatively, the anaerobic sludge 56 is drained from anaerobic water purification subsystem 12 by means of a drain valve 60 .
Anaerobic effluent produced by anaerobic water purification subsystem 12 flows to aerobic water purification subsystem 14 via an internal conduit 62 for further treatment of organic matter. Alternatively, the transition of wastewater from the anaerobic water purification subsystem 12 to aerobic water purification subsystem 14 is achieved by an external conduit 64 . Additionally or alternatively, anaerobic and/or aerobic effluent is returned to pre-acidification tank 30 from anaerobic water purification subsystem 12 through recirculation pipe 66 , and/or from aerobic water purification subsystem 14 through recirculation pipe 68 .
Aerobic water purification subsystem 14 comprises gas diffusers 70 that can be installed on the bottom of aerobic water purification subsystem 14 or above the bottom of aerobic water purification subsystem 14 , consistent with the Moving Bed Biofilm reactor (MBBR) configuration or with the Moving Bed Clarifying Reactor (MBCR) configuration as shown in PCT/IL 2009/000825, respectively.
When the MBCR configuration is applied, gas diffuser outlets 70 are arranged generally between an upper biological treatment turbulence region 72 and a lower solids settling region 74 , and provide gas bubbles which move upwardly through wastewater in aerobic water purification subsystem 14 and through a plurality of biomass carriers 18 disposed within upper biological treatment turbulence region 72 , and create turbulent motion of wastewater in upper biological treatment turbulence region 72 . The gas bubbles, typically of pressurized air, are supplied to outlets 70 via a gas inlet 76 . The outlets 70 may include one or more coarse or fine bubble diffusers and jets.
Sludge 77 (S) produced in aerobic water purification subsystem 14 is drained by valve 78 . Treated effluent 80 (E) leaves aerobic water purification subsystem 14 and reactor 10 via a wedge wire screen 82 coupled to a wastewater outlet in order to prevent carriers 18 from leaving aerobic water purification subsystem 14 .
It is a particular feature of the present invention that most of the organic matter conversion is performed in the anaerobic water purification subsystem 12 of reactor 10 . It is another particular feature of the present invention that the aerobic water purification subsystem 14 is filled with biomass carriers 18 which increase the effective surface area of subsystem 14 and immobilize bacteria, thereby preventing wash out and conversion. These two features significantly reduce the amount of energy required for aeration in aerobic water purification subsystem 14 compared to conventional systems.
Reference is now made to FIG. 2 , which is a simplified illustration of one embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 . As seen in FIG. 2 , there is provided an integrated reactor, designated generally by reference numeral 100 , which includes an anaerobic water purification subsystem 102 , receiving water to be treated, such as waste water, at an inlet 104 . Preferably the waste water is supplied from above by means of a plurality of nozzles 106 , which are coupled to inlet 104 . The water level in anaerobic water purification subsystem 102 is typically as designated by reference numeral 107 .
The anaerobic water purification subsystem 102 provides an anaerobic-treated water output via an outlet 108 to an aerobic water purification subsystem 110 , integrated with the anaerobic water purification subsystem 102 and preferably physically located thereabove, which receives the anaerobic-treated water output at an inlet 112 and provides an anaerobic- and aerobic-treated water output as an effluent at an outlet 114 . If appropriate, the effluent from outlet 114 may be further treated by any suitable technique.
In accordance with a preferred embodiment of the present invention, the anaerobic water purification subsystem 102 includes a multiplicity of biomass carriers 120 which are disposed in water to be treated. Biomass carriers 120 are operative to support anaerobic microorganisms. The structure and operation of a preferred embodiment of biomass carriers is described in applicant/assignee's European Published Patent Application No. 1401775 and PCT Published Patent Application No. WO 2009/10718, the disclosures of which are hereby incorporated by reference. Any other suitable biomass carriers may be employed.
Optionally, an inert gas, such as nitrogen may be periodically introduced into the water to be treated via a gas supply inlet 122 in order to produce limited relative movement of the biomass carriers 120 in order to prevent clogging. Alternatively, this can be accomplished by a circulation pump disposed within the subsystem 102 and/or by a biogas compressor injecting biogas into subsystem 102 .
Biogas, principally methane and carbon dioxide, generated by the anaerobic water purification in subsystem 102 rises to a gas collection volume 124 in a headspace above the water being treated in anaerobic water purification subsystem 102 and is preferably released for use via a generated gas outlet 126 . Optionally, some of the generated gas may be supplied via gas supply inlet 122 in addition to or in place of the inert gas.
Biogas pressure in gas collection volume 124 causes the anaerobically treated water to rise from anaerobic subsystem 102 through outlet 108 to inlet 112 in aerobic water treatment subsystem 110 . Inlet 112 is preferably located in a lower portion of the aerobic subsystem 110 . Disposed above inlet 112 there are preferably provided a plurality of air diffusers 130 which are coupled to a source of pressurized air 132 , such as a compressor, via a pressurized air conduit 134 .
The water level in aerobic water purification subsystem 110 is typically as designated by reference numeral 137 . A multiplicity of biomass carriers 140 are disposed in water to be treated in aerobic water purification subsystem 100 and are operative to support anaerobic microorganisms. Any other suitable biomass carriers may be employed. Biomass carriers 140 are generally confined to the volume above diffusers 130 , by the movement of air bubbles of the diffusers.
At the bottom of the aerobic water purification subsystem 110 , below diffusers 130 there is preferably provided a sludge settlement volume 142 , which is equipped with a sludge outlet 144 .
Preferably, the structure and operation of the aerobic water purification subsystem 110 is in accordance with the teachings of applicant/assignee's European Published Patent Application Nos. 1401775 and 2049443, and U.S. Published Patent Application No. 2009/0211972, the disclosure of which is hereby incorporated by reference.
Reference is now made to FIG. 3 , which is a simplified illustration of another embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 . As seen in FIG. 3 , there is provided an integrated reactor, designated generally by reference numeral 200 , which includes an anaerobic water purification subsystem 202 , receiving water to be treated, such as waste water, at an inlet 204 . Preferably the waste water is supplied from above by means of a plurality of nozzles 206 , which are coupled to inlet 204 . The water level in anaerobic water purification subsystem 202 is typically as designated by reference numeral 207 .
The anaerobic water purification subsystem 202 provides an anaerobic-treated water output via an outlet 208 to an aerobic water purification subsystem 210 , integrated with the anaerobic water purification subsystem 202 and preferably physically located thereabove, which receives the anaerobic-treated water output at an inlet 212 and provides an anaerobic- and aerobic-treated water output as an effluent at an outlet 214 . If appropriate, the effluent from outlet 214 may be further treated by any suitable technique.
In accordance with a preferred embodiment of the present invention, the anaerobic water purification subsystem 202 includes a multiplicity of biomass carriers 220 which are disposed in water to be treated. Biomass carriers 220 are operative to support anaerobic microorganisms. The structure and operation of a preferred embodiment of biomass carriers is described in applicant/assignee's European Published Patent Application No. 1401775 and PCT Published Patent Application No. WO 2009/10718, the disclosures of which are hereby incorporated by reference. Any other suitable biomass carriers may be employed.
Optionally, an inert gas, such as nitrogen may be periodically introduced into the water to be treated via a gas supply inlet 222 in order to produce limited relative movement of the biomass carriers 220 in order to prevent clogging. Alternatively, this can be accomplished by a circulation pump disposed within the subsystem 202 .
Biogas, principally methane and carbon dioxide, generated by the anaerobic water purification in subsystem 202 rises to a gas collection volume 224 in a headspace above the water being treated in anaerobic water purification subsystem 202 and is preferably released for use via a generated gas outlet 226 . Optionally, some of the generated gas may be supplied via gas supply inlet 222 in addition to or in place of the inert gas.
Biogas pressure in gas collection volume 224 causes the anaerobically treated water to rise from anaerobic subsystem 202 through outlet 208 to inlet 212 in aerobic water treatment subsystem 210 . Inlet 212 is preferably located in a lower portion of the aerobic subsystem 210 . Disposed above inlet 212 there are preferably provided a plurality of air diffusers 230 which are coupled to a source of pressurized air 232 , such as a compressor, via a pressurized air conduit 234 .
The water level in aerobic water purification subsystem 210 is typically as designated by reference numeral 237 . A multiplicity of biomass carriers 240 are disposed in water to be treated in aerobic water purification subsystem 200 and are operative to support anaerobic microorganisms. Any other suitable biomass carriers may be employed. Biomass carriers 240 are generally confined to the volume above diffusers 230 , by the movement of air bubbles of the diffusers.
Preferably the structure and operation of the aerobic water purification subsystem 210 is in accordance with the teachings of applicant/assignee's European Published Patent Application Nos. 1401775 and 2049443, and U.S. Published Patent Application No. 2009/0211972, the disclosure of which is hereby incorporated by reference.
Reference is now made to FIG. 4 , which is a simplified illustration of yet another embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 . As seen in FIG. 4 , there is provided an integrated reactor, designated generally by reference numeral 300 , which includes an anaerobic water purification subsystem 302 , receiving water to be treated, such as waste water, at an inlet 304 . Preferably the waste water is supplied from below by means of a plurality of nozzles 306 , which are coupled to inlet 304 . The water level in anaerobic water purification subsystem 302 is typically as designated by reference numeral 307 .
The anaerobic water purification subsystem 302 provides an anaerobic-treated water output via an outlet 308 to an aerobic water purification subsystem 310 , integrated with the anaerobic water purification subsystem 302 and preferably physically located thereabove, which receives the anaerobic-treated water output at an inlet 312 and provides an anaerobic- and aerobic-treated water output as an effluent at an outlet 314 . If appropriate, the effluent from outlet 314 may be further treated by any suitable technique.
In accordance with a preferred embodiment of the present invention, the anaerobic water purification subsystem 302 includes a multiplicity of biomass carriers 320 which are disposed in water to be treated. Biomass carriers 320 are operative to support anaerobic microorganisms. The structure and operation of a preferred embodiment of biomass carriers is described in applicant/assignee's European Published Patent Application No. 1401775 and PCT Published Patent Application No. WO 2009/10718, the disclosures of which are hereby incorporated by reference. Any other suitable biomass carriers may be employed.
Optionally, an inert gas, such as nitrogen may be periodically introduced into the water to be treated via a gas supply inlet 322 in order to produce limited relative movement of the biomass carriers 320 in order to prevent clogging. Alternatively, this can be accomplished by a circulation pump disposed within the subsystem 302 .
Biogas, principally methane and carbon dioxide, generated by the anaerobic water purification in subsystem 302 rises to a gas collection volume 324 in a headspace above the water being treated in anaerobic water purification subsystem 302 and is preferably released for use via a generated gas outlet 326 . Optionally, some of the generated gas may be supplied via gas supply inlet 322 in addition to or in place of the inert gas.
Biogas pressure in gas collection volume 324 causes the anaerobically treated water to rise from anaerobic subsystem 302 through outlet 308 to inlet 312 in aerobic water treatment subsystem 310 . Inlet 312 is preferably located in a lower portion of the aerobic subsystem 310 . Disposed above inlet 312 there are preferably provided a plurality of air diffusers 330 which are coupled to a source of pressurized air 332 , such as a compressor, via a pressurized air conduit 334 .
The water level in aerobic water purification subsystem 310 is typically as designated by reference numeral 337 . A multiplicity of biomass carriers 340 are disposed in water to be treated in aerobic water purification subsystem 300 and are operative to support anaerobic microorganisms. Any other suitable biomass carriers may be employed. Biomass carriers 340 are generally confined to the volume above diffusers 330 , by the movement of air bubbles of the diffusers.
At the bottom of the aerobic water purification subsystem 310 , below diffusers 330 there is preferably provided a sludge settlement volume 342 , which is equipped with a sludge outlet 344 .
Preferably the structure and operation of the aerobic water purification subsystem 310 is in accordance with the teachings of applicant/assignee's European Published Patent Application Nos. 1401775 and 2049443, and U.S. Published Patent Application No. 2009/0211972, the disclosure of which is hereby incorporated by reference.
Reference is now made to FIG. 5 , which is a simplified illustration of still another embodiment of the synergetic anaerobic/aerobic water purification system of FIG. 1 . As seen in FIG. 5 , there is provided an integrated reactor, designated generally by reference numeral 400 , which includes an anaerobic water purification subsystem 402 , receiving water to be treated, such as waste water, at an inlet 404 . Preferably the waste water is supplied from below by means of a plurality of nozzles 406 , which are coupled to inlet 404 . The water level in anaerobic water purification subsystem 402 is typically as designated by reference numeral 407 .
The anaerobic water purification subsystem 402 provides an anaerobic-treated water output via an outlet 408 to an aerobic water purification subsystem 410 , integrated with the anaerobic water purification subsystem 402 and preferably physically located thereabove, which receives the anaerobic-treated water output at an inlet 412 and provides an anaerobic- and aerobic-treated water output as an effluent at an outlet 414 . If appropriate, the effluent from outlet 414 may be further treated by any suitable technique.
In accordance with a preferred embodiment of the present invention, the anaerobic water purification subsystem 402 includes a multiplicity of biomass carriers 420 which are disposed in water to be treated. Biomass carriers 420 are operative to support anaerobic microorganisms. Any other suitable biomass carriers may be employed.
Optionally, an inert gas, such as nitrogen may be periodically introduced into the water to be treated via a gas supply inlet 422 in order to produce limited relative movement of the biomass carriers 420 in order to prevent clogging. Alternatively, this can be accomplished by a circulation pump disposed within the subsystem 402 .
Biogas, principally methane and carbon dioxide, generated by the anaerobic water purification in subsystem 402 rises to a gas collection volume 424 in a headspace above the water being treated in anaerobic water purification subsystem 402 and is preferably released for use via a generated gas outlet 426 . Optionally, some of the generated gas may be supplied via gas supply inlet 422 in addition to or in place of the inert gas.
Biogas pressure in gas collection volume 424 causes the anaerobically treated water to rise from anaerobic subsystem 402 through outlet 408 to inlet 412 in aerobic water treatment subsystem 410 . Inlet 412 is preferably located in a lower portion of the aerobic subsystem 410 . Disposed above inlet 412 there are preferably provided a plurality of air diffusers 430 which are coupled to a source of pressurized air 432 , such as a compressor, via a pressurized air conduit 434 .
The water level in aerobic water purification subsystem 410 is typically as designated by reference numeral 437 . A multiplicity of biomass carriers 440 are disposed in water to be treated in aerobic water purification subsystem 400 and are operative to support anaerobic microorganisms. Any other suitable biomass carriers may be employed. Biomass carriers 440 are generally confined to the volume above diffusers 430 , by the movement of air bubbles of the diffusers.
Preferably the structure and operation of the aerobic water purification subsystem 410 is in accordance with the teachings of applicant/assignee's European Published Patent Application Nos. 1401775 and 2049443, and U.S. Published Patent Application No. 2009/0211972, the disclosure of which is hereby incorporated by reference.
Reference is now made to FIGS. 6 & 7 , which show experimental results of use of the system in accordance with the embodiment of FIG. 1 of the present invention.
In an experiment shown in FIG. 6 , a lab scale anaerobic reactor having a volume of 19 liters, a height of 2 meters and a diameter of 11 cm, was used for a first experiment illustrating the principle of immobilizing anaerobic biomass onto biomass carrier material. A fermented molasses product was fed to the reactor. The volumetric loading rate (VLR) was controlled by adjustments of the COD concentration and feed flow. The reactor was operated in a downflow configuration. The fluid velocity ranged from 0.25 m/h to 0.67 m/h. The pH level was adjusted to pH 7 with NaOH, and the temperature was a constant 35° C.
FIG. 6 shows the relation between the applied VLR (in kg/m 3 /d) and the conversion (in %) of COD and VFA (with COD conversion shown as a solid line, VFA conversion shown as a dashed line and VLR shown as a dashed-dotted line). During the experiment, an increase in biomass development upon the carrier material was observed, which allowed for a higher VLR. The system showed a stable conversion of VFA and COD up to a VLR of 22 kg/m 3 /d.
In an experiment shown in FIG. 7 , a dynamic anaerobic aerobic (DANA) reactor with an anaerobic part having a volume of 2.35 cubic meters, a height of 3 meters, a diameter of 1 meter, a carrier bed height of 1.3 meter, a surface area of 0.78 square meters, and an aerobic part having a height of 3.5 meters, a carrier bed having a height of 1.3 meters, and a diameter of 1 meter, was used to treat waste water from a starch factory. Waste water with an average COD concentration of 5 g/l was treated. The anaerobic reactor was operated in a downflow mode. At a maximum of 200 l/h of waste water fed, combined with a recirculation flow of 400 l/h, the downflow velocity reached was 0.76 m/h. The dissolved oxygen level in the aerobic tank was maintained at 2 mg/l. Temperature of the influent was 35° C.-37° C., and the pH was maintained at 6.8 with NaOH.
Inoculation of the anaerobic tank was achieved using 10% inoculated carrier material at the top part of the carrier bed. Within one month a volumetric loading rate (VLR) of 10 kg/m 3 /d was reached. FIG. 7 shows COD and VFA conversion (in %) of the total DANA reactor plotted against the VLR (in kg/m 3 /d). The average conversion of the anaerobic part was 80% and the remaining COD/VFA was 90% converted by the aerobic reactor. The total average conversion for the DANA reactor was 95%.
It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather, the scope of the invention includes both combinations and subcombinations of various features described hereinabove as well as modifications and variations thereof which would occur to persons skilled in the art upon reading the foregoing and which are not in the prior art.
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An anaerobic water purification system including an anaerobic water purification unit receiving water to be treated and providing an anaerobic-treated water output and biomass carriers for supporting anaerobic microorganisms in the anaerobic water purification unit.
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FIELD OF THE INVENTION
[0001] The present invention relates to reclosable plastic bags of the type in which perishable food products and other goods are packaged for sale to consumers in retail outlets. More specifically, the present invention relates to a method of producing plastic bags which are concurrently manufactured to include a fin seal, and the manner of producing such bags so that they may more readily be tom open through the fin seal.
DESCRIPTION OF THE PRIOR ART
[0002] The present invention relates to improvements in the package-making art and may be practiced in the manufacture of reclosable thermoplastic bags and packages of the type that may be used for various consumer products. Such packages often include a form of peel-seal to render the package moisture-tight and/or airtight prior to the initial opening, and/or a tamper-evident seal. A zipper means protects any remainder of the product therein after the initial opening.
[0003] The indicated art is fairly well developed but nevertheless remains open to improvements contributing to increased efficiency and cost-effectiveness. In the prior art, McMahon et al. (U.S. Pat. No. 4,909,017) discloses a method of making a form-fill and seal bag having a reclosable fastener. Prior to entering the form-fill and seal machine, fastener strips are attached to the surface of the film transverse to the running direction at bag length intervals. The fastener strips contain pre-joined interlocked rib and groove strips. Only one of the strips is attached to a top surface of the film with the other strip facing upwardly or, in other words, inwardly toward the interior of the bag to be formed. The attached strips are secured in one form at the center of the film and each strip is less than half of the film width. The film is then advanced to the form-fill and seal machine and is drawn down over a forming collar and about the filling tube, with the longitudinal side edge margins of the film brought together and seamed with a fin seal to form a tube. Cross-seals are made across the tube to join the unattached fastener strip to the film to form the closure and to form the bottom of the following bags. A further seal may be provided above the fastener to provide tamper-evident sealing. In such case, an easy-open feature such as a line of weakness in the form of a line of perforations or a score line would be provided for the bag between the top seal and the fastener strip.
[0004] A potential problem with the above method is that the bag walls contain layers which will be doubled or tripled in the area of the fin seal which must be tom through to open the bag. While the line of weakness aids in starting the tear through the bag walls, tearing through multiple layers of the fin seal and the underlying bag may be difficult for the consumer to achieve. A significant step would involve reducing the amount of layers of bag film in the fin seal or weakening the layers of bag film in the fin seal area. When opening the bag by tearing along provided perforations or a score line in the bag, the fin area would be a reduced impediment, thus providing the bag with an easy-open feature.
SUMMARY OF THE INVENTION
[0005] Accordingly, the present invention relates to a method for producing a reclosable plastic bag with an easy-open feature in which a length of bag making film is advanced in a bag forming direction. A length of fastener having first and second mateable profile strips is attached to a mid-portion of the bag making film transverse to the bag forming direction, while leaving sides of film on opposite ends of the length of fastener. A weakness area is created in at least one of the sides with the weakness area comprising either an aperture, multi-line perforations of the bag film, scoring of the bag film, or any other weakening method known to those skilled in the art. The weakness area aligns with a flange portion of one of the profile strips or with an area of film adjacent the flange portion.
[0006] In a later stage of manufacture, the weakness area extends into a side margin that runs to an edge of one of the sides. The side margin of one side, together with a side margin of an opposite side, is sealed in a fin seal to form a tube. The unattached length of fastener is sealed to the inner surface of the tube that includes the fin seal. When the fin seal is formed, and if the weakness area comprises an aperture aligning with the flange portion, a portion of the opposite side margin of the fin seal is sealed to the flange portion of the fastener through the aperture. If the weakness area comprises an aperture aligning with an area of film adjacent the flange portion, a portion of the opposite side margin of the fin seal is sealed to the bag making film of the front bag wall through the aperture. Alternatively, a weakness area other than an aperture can be created when the fin seal is formed, instead of at the stage of manufacturing described earlier. In the last stage of manufacturing, the tube is cross-sealed at spaced intervals to form a bag. An opening notch is provided to create a tear line that will run through the weakness area.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Further objects and advantages of the invention will become apparent from the following description and claims taken in conjunction with the accompanying drawings, in which:
[0008] FIG. 1 is a plan view depicting a first embodiment of the present invention wherein a perforated fastener with an adjacent elliptical aperture is formed on a section of thermoplastic film;
[0009] FIG. 2A is a side view depicting the first embodiment of the present invention wherein the thermoplastic film is folded to provide a fin seal area;
[0010] FIG. 2B is a sectional view depicting the first embodiment of the present invention taken from reference line 2 B- 2 B of FIG. 2A ;
[0011] FIG. 3A is a side view depicting the first embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
[0012] FIG. 3B is a sectional view depicting the first embodiment of the present invention taken from reference line 3 B- 3 B of FIG. 3A ;
[0013] FIG. 4 is a side view depicting the first embodiment of the present invention wherein the fin seal has been sealed to a wall of the reclosable bag;
[0014] FIG. 5 is a side view depicting the first embodiment of the present invention with a reclosable bag shown in an opening condition;
[0015] FIG. 6 is a plan view depicting a second embodiment of the present invention wherein a perforated fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
[0016] FIG. 7A is a side view depicting the second embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
[0017] FIG. 7B is a sectional view depicting the second embodiment of the present invention taken from reference line 7 B- 7 B of FIG. 7A ;
[0018] FIG. 8 is a side view depicting the second embodiment of the present invention wherein a reclosable bag has been formed;
[0019] FIG. 9 is a side view depicting the second embodiment of the present invention with the reclosable bag shown in an opening condition;
[0020] FIG. 10 is a plan view depicting a third embodiment of the present invention wherein a perforated fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
[0021] FIG. 11 is a side view depicting the third embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
[0022] FIG. 12 is a side view depicting the third embodiment of the present invention wherein a reclosable bag has been formed;
[0023] FIG. 13 is a side view depicting the third embodiment of the present invention with the reclosable bag shown in an opening condition;
[0024] FIG. 14 is a plan view depicting a fourth embodiment of the present invention wherein a fastener with an adjacent elliptical aperture is formed on a section of thermoplastic film;
[0025] FIG. 15 is a side view depicting the fourth embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
[0026] FIG. 16 is a side view depicting the fourth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch on the edge of the reclosable bag;
[0027] FIG. 17 is a side view depicting the fourth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in the cross-seal of the reclosable bag;
[0028] FIG. 18 is a side view depicting the fourth embodiment of the present invention with the reclosable bag shown in an opening condition;
[0029] FIG. 19 is a side view depicting the fourth embodiment of the present invention with the reclosable bag shown in an alternative opening condition;
[0030] FIG. 20 is a plan view depicting a fifth embodiment of the present invention wherein a fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
[0031] FIG. 21 is a side view depicting the fifth embodiment of the present invention wherein a fin seal has been formed at a cross jaw section of a form-fill and seal machine;
[0032] FIG. 22 is a side view depicting the fifth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch on the edge of the reclosable bag;
[0033] FIG. 23 is a side view depicting the fifth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in the cross-seal of the reclosable bag;
[0034] FIG. 24 is a side view depicting the fifth embodiment of the present invention with the reclosable bag shown in an opening condition;
[0035] FIG. 25 is a side view depicting the fifth embodiment of the present invention with the reclosable bag shown in an alternative opening condition;
[0036] FIG. 26 is a plan view depicting a sixth embodiment of the present invention wherein a fastener with adjacent multi-line perforated areas of weakness is formed on a section of thermoplastic film;
[0037] FIG. 27 is a side view depicting the sixth embodiment of the present invention wherein a fin seal has been formed at a cross-jaw section of a form-fill and seal machine;
[0038] FIG. 28 is a side view depicting the sixth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch on the edge of the reclosable bag;
[0039] FIG. 29 is a side view depicting the sixth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in the cross-seal of the reclosable bag;
[0040] FIG. 30 is a side view depicting the sixth embodiment of the present invention with the reclosable bag shown in an opening condition;
[0041] FIG. 31 is a side view depicting the sixth embodiment of the present invention with the reclosable bag shown in an alternative opening condition;
[0042] FIG. 32 is a side view depicting the sixth embodiment of the present invention wherein a reclosable bag has been formed with a tear notch formed in an alternative position in the cross-seal of the reclosable bag; and
[0043] FIG. 33 is a side view of the sixth embodiment of the present invention with the reclosable bag shown in an alternative opening condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Referring now to the drawings in detail wherein like numerals indicate like elements throughout the several views, a continuous length of thermoplastic packaging film 10 is shown in FIG. 1 prior to sealing, where the film would be fed to a form-fill and seal machine in movement direction 12 .
[0045] In accordance with the present method, a fastener strip 14 with male and female profiles joined by their interlocking elements is attached to the midsection of the film 10 extending in a direction transverse to movement direction 12 . Only profile 16 that sits on the thermoplastic film 10 is attached to the film. The other profile 18 , as depicted in FIG. 2B , is secured only by the engagement of the interlocking elements.
[0046] In FIG. 1 , a line of weakness is set along perforation axis 19 on a flange of the profile 16 prior to its attachment to the film. Alternatively, a line of weakness may also be set along perforation axis 20 prior to its attachment to the film, with the positioning of the perforation axis 20 illustrated in FIG. 2A . The lines of weakness may be perforations, dimples, scoring of the film, or any other tearing axes known to those skilled in the art. The positioning of the lines of weakness will hereinafter be referred to as on perforation axis 19 , since perforation axis 20 is preferably collinear with perforation axis 19 . Also, any tearing action or dimensioning regarding the present invention similarly affects perforation axis 20 as well as perforation axis 19 . As such, perforation axes 19 and 20 are parallel to the interlocking profiles and end short of the longitudinal ends of the fastener strip, thereby protecting the lines of weakness from prematurely tearing open during the manufacturing process.
[0047] Sides 21 and 22 of thermoplastic film extending to the longitudinal film edges are provided on opposite sides of the fastener strip 14 . In this regard the combined length of sides 21 and 22 is greater than that of the fastener strip to allow proper sealing, as will be discussed later. An area of weakness is created on the side 21 to align with the perforation axis 19 or to be to the right of and parallel with the fastener strip 14 . The area of weakness may comprise an aperture 23 , as shown in FIGS. 1-5 , 14 - 18 , or lines of weakness 80 , 81 , 84 , 86 , as shown in FIGS. 6-13 , 20 - 33 .
[0048] As shown in FIG. 1 the aperture 23 , preferably elliptical, is cut or punched through the thermoplastic film 10 such that the longitudinal axis of the aperture 23 aligns with the perforation axis 19 . The outer edge of aperture 23 should be in proximity to a longitudinal edge 24 of the thermoplastic film, but should also allow a sufficient buffer between the longitudinal edge to prevent the film from tearing to the aperture 23 from the longitudinal edge during the manufacturing process.
[0049] As shown in FIGS. 2A and 2B , during the bag forming process the thermoplastic film 10 is folded on the form-fill and seal machine to bring side margins 25 and 26 , respectively adjacent the longitudinal edges of the film, together in a fin to thereby form the thermoplastic film into a tube. The wall sections 28 and 30 , corresponding to sides 21 and 22 that extend from the opposite ends 32 and 34 of the zipper strip, are joined by the fin to define a rear surface of the tube that faces the fastener strip 14 . In FIG. 3A the side margins 25 and 26 are seamed together to form a fin seal 35 , and a cross-jaw sealing section is used to seal wall sections 28 and 30 to the profile 18 . When folding the film to form the fin seal 35 , more than half of the aperture 23 should be on the side margin 25 with the remainder of the aperture on the adjacent wall section 28 .
[0050] As shown in FIG. 3B , the use of the cross-jaw sealing section of a form-fill and seal machine (not shown) seals wall sections 28 , 30 to an upper flange 36 of profile strip 18 of the fastener strip 14 while preferably avoiding pressure on the perforation axes 19 and 20 . In FIG. 4 , the thermoplastic film is folded into a tube with the fin seal 35 sealed to wall section 28 . Because of the removed layers of the wall section 28 created by the aperture 23 , the fin seal side margin 26 now seals directly to the upper flange 36 of the profile strip 18 . The thermoplastic film is now formed as a reclosable bag 38 by forming a bottom cross-seal and a top cross-seal 39 above the profiles.
[0051] To assist in reaching the perforation axes 19 , 20 of the reclosable bag 38 during an opening operation, a tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . For the tear notch 50 , the edge selected should be closer to the fold line 52 in the aperture than to the folded-over ends 54 and 55 of the aperture.
[0052] If a hermetic seal is necessary for the notch 50 , a melting operation is used to form the notch. A peripheral melt zone 56 would join the front and rear walls of the package around the notch and hence would seal the contents of the interior of the reclosable bag from exposure via the notch.
[0053] FIG. 5 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, thereby allowing the tearing force to continue to a resultant perforation 57 of the bag. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by exposed sealing areas 59 since the tearing force is exposed to only the side margin 26 of the fin seal.
[0054] A second embodiment of the present invention is shown in FIG. 6 . In the figure, the weakness area comprises a line of weakness 80 instead of the aperture 23 . An opposing line of weakness 81 is positioned on the opposite side of the fastener 14 . The lines of weakness 80 , 81 may be a plurality of perforated lines on the film used to form the reclosable bag, a dimpling of the film, a scoring of the film, or any other tearing axis known to those skilled in the art. Shown as a plurality of perforated lines, the lines of weakness 80 , 81 align with the perforation axis 19 . The outer edge of the lines of weakness 80 , 81 should be in proximity to the longitudinal edges 24 , 82 of the film, but should also allow a sufficient buffer between the longitudinal edges to prevent the film from tearing to the lines of weakness from the longitudinal edges during the manufacturing process.
[0055] Using the bag forming process described in FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIGS. 7A and 7B . When the wall sections 28 and 30 are folded to form the fin seal 35 , more than half of the lines of weakness 80 should be on the side margin 25 with any remainder on the adjacent wall section 28 . Similarly, more than half of the line of weakness 81 should be on the side margin 26 preferably in alignment with the line of weakness 80 .
[0056] In FIG. 8 , the thermoplastic film is formed into a reclosable bag by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 while preferably avoiding pressure on the perforation axes 19 and 20 . Alternatively, the line of weakness 81 can be applied on the wall section 30 and the side margin 26 after the fin seal is formed, instead of at the stage of manufacturing described earlier. The bottom cross-seal and the top cross-seal 39 are then formed, thereby creating the reclosable bag 38 .
[0057] To assist in reaching the perforations of the reclosable bag 38 during an opening operation, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a seal is necessary for the notch 50 , a melting operation is used to form the notch. The peripheral melt zone 56 would join the front and rear walls of the package around the notch.
[0058] FIG. 9 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, allowing the tearing force to continue to a resultant perforation 57 of the bag. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by the lines of weakness 80 , 81 , since the lines of weakness produce a weakened layer of the fin seal 35 .
[0059] A third embodiment of the present invention is shown in FIG. 10 . In the figure, a line of weakness 84 is created on side 21 of the film 10 with the line of weakness 84 less than half the length of the line of weakness 80 . Additionally, a line of weakness 86 with a length less than half the length of the line of weakness 81 is created on side 22 of the film 10 . Similar to the placements of lines of weakness 80 , 81 , the lines of weakness 84 , 86 align with the perforation axes 19 and 20 .
[0060] Using the bag forming process described for FIGS. 2A and 3A , a bag with the fin seal is shown in FIG. 11 . When the wall sections are folded to form the fin seal 35 , lines of weakness 84 , 86 should be fully on the fin seal with the lines of weakness ending short of the fold line 52 and with the lines of weakness preferably in alignment with each other. This positioning of the lines of weakness 84 , 86 allows the resultant reclosable bag to be hermetically sealed since the lines of weakness are not on any bag wall.
[0061] In FIG. 12 , the thermoplastic film for forming the bag is folded into a tube by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 while preferably avoiding pressure on the perforation axes 19 , 20 . Alternatively, the line of weakness 86 can be applied in the side margin 26 after the fin seal is formed, instead of at the stage of manufacturing described earlier. The bottom cross-seal and the top cross-seal 39 are then formed, thereby creating the reclosable bag 38 . To assist in reaching the perforations, the tear notch 50 is formed by cutting or by melting away material from an edge of the reclosable bag 38 . A melting operation is used to form a hermetic seal for the notch. The peripheral melt zone 56 joins the front and rear walls of the package around the notch and hence seals the contents of the interior of the reclosable bag 38 from exposure via the notch.
[0062] FIG. 13 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, allowing the tearing force to continue to the resultant perforation 57 of the bag. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by the lines of weakness 84 , 86 as the tearing force encounters the weakened layers of the fin seal 35 .
[0063] A fourth embodiment of the present invention is shown in FIG. 14 . In the figure, the aperture 23 is cut or punched through the thermoplastic film 10 on the side 21 such that the longitudinal axis of the aperture aligns to an area to the right of and parallel with the fastener strip 14 . The outer edge of the aperture 23 should be in proximity to the longitudinal edge 24 of the film, but should allow a sufficient buffer between the longitudinal edge to prevent the film from tearing to the aperture 23 from the longitudinal edge during the manufacturing process.
[0064] Using the bag forming process described in FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIG. 15 . When the wall sections 28 , 30 are folded to form the fin seal 35 , more than half of the aperture 23 should be on the side margin 25 with the remainder on the adjacent wall section 28 . A cross-jaw sealing section of a form-fill and seal machine (not shown) seals the wall sections 28 , 30 to an upper flange 36 of profile strip 18 of the fastener strip 14 .
[0065] In FIG. 16 , the thermoplastic film for forming the bag is folded into a tube with the fin seal 35 sealed to wall section 28 . Because of the removed layers of the wall section 28 created by the aperture 23 , the fin seal margin 26 now seals directly to the thermoplastic film 10 of the interior bag wall 87 above the fastener strip 14 . The thermoplastic film is now formed as a reclosable bag 38 by forming the bottom seal and the top cross-seal 39 .
[0066] To assist in reaching the perforations of the reclosable bag 38 during an opening operation, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a seal is necessary for the notch 50 , a melting operation is used to form the notch. A peripheral melt zone 56 would join the front and rear walls of the package around the notch and hence would seal the contents of the interior of the reclosable bag from exposure via the notch. As shown in FIG. 17 , the alternative tear notch 51 may be formed by cutting or melting away material from the top cross-seal 39 . For the tear notches 50 and 51 , the edge selected should be closest to the fold line 52 .
[0067] FIG. 18 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, thereby allowing the tearing force along the top of the fastener 14 to the aperture 23 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and thereby prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to only the side margin 26 of the fin seal. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0068] FIG. 19 depicts the reclosable bag 38 in an alternative opening condition using the tear notch 51 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force to proceed along the top of the fastener 14 to the aperture 23 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to only the side margin 26 of the fin seal. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0069] A fifth embodiment of the present invention is shown in FIG. 20 . In the figure, the lines of weakness 80 , 81 align to an area to the right of and parallel with the fastener strip 14 . The lines of weakness 80 , 81 should be in proximity to the longitudinal edges 24 , 82 of the film, but should also allow a sufficient buffer between the longitudinal edges to prevent the film from tearing to the lines of weakness from the longitudinal edges during manufacture.
[0070] Using the bag forming process described in FIGS. 2A and 3A , a-bag with the fin seal 35 is shown in FIG. 21 . When the wall sections 28 and 30 are folded to form the fin seal 35 , more than half of the line of weakness 80 should be on the side margin 25 with the remainder on the adjacent wall section 28 . Similarly, more than half of the line of weakness 81 should be on the side margin 26 preferably in alignment with the line of weakness 80 .
[0071] In FIG. 22 , the thermoplastic film for forming the bag is folded into a tube with a fin seal 35 by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 . Alternatively the line of weakness 81 can be applied in the side margin 26 after the fin seal 35 is formed, instead of at the stage of manufacturing described earlier. The bottom cross-seal and the top cross-seal 39 are formed, thereby creating the reclosable bag 38 .
[0072] To assist in reaching the perforations of the reclosable bag 38 during an opening operation, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a seal is necessary for the notch 50 , a melting operation is used to form the notch. A peripheral melt zone 56 would join the front and rear walls of the package around the notch 50 and hence would seal the contents of the interior of the reclosable bag from exposure via the notch. As shown in FIG. 23 , the alternative tear notch 51 may be formed by cutting or melting away material from the top cross-seal 39 .
[0073] FIG. 24 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, thereby allowing the tearing force along the top of the fastener 14 to the lines of weakness 80 , 81 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and thereby prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to the lines of weakness. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0074] FIG. 25 depicts the reclosable bag 38 in an alternative opening condition using the tear notch 51 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force along the top of the fastener 14 to the lines of weakness 80 , 81 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and thereby prevents the package from being destroyed. As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force is exposed to the lines of weakness 80 , 81 on the fin seal. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0075] A sixth embodiment of the present invention is shown in FIG. 26 . In the figure, a line of weakness 84 is created on side 21 of the film 10 with the line of weakness less than half the length of the line of weakness 80 . Additionally, a line of weakness 86 with a length less than half the length of the line of weakness 81 is created on side 22 of the film 10 . Similar to the lines of weakness 80 , 81 in FIG. 20 , the lines of weakness 84 , 86 in FIG. 26 align to an area to the right of and parallel with the fastener strip 14 .
[0076] Using the bag forming process described for FIGS. 2A and 3A , a bag with the fin seal 35 is shown in FIG. 27 . When the wall sections are folded to form the fin seal 35 , lines of weakness 84 , 86 should be fully on the fin seal with the lines of weakness ending short of the fold line 52 and preferably in alignment with each other. This allows the resultant reclosable bag to be hermetically sealed since the lines of weakness 84 , 86 are not on any bag wall.
[0077] In FIG. 28 , the thermoplastic film for forming the bag is folded into a tube by the form-fill and seal machine. The wall sections 28 and 30 are sealed to the upper flange 36 . The bottom cross-seal and the top cross-seal 39 are formed, thereby creating the reclosable bag 38 . Alternatively, the line of weakness 86 can be applied on the side margin 26 after the fin seal is formed instead of at the stage of manufacturing described earlier.
[0078] To assist in reaching the perforations, the tear notch 50 is formed by cutting or melting away material from an edge of the reclosable bag 38 . If a hermetic seal is necessary for the notch 50 , a melting operation is used to form the notch. The peripheral melt zone 56 would join the front and rear walls of the package around the notch and hence would seal the contents of the interior of the reclosable bag from exposure via the notch. As shown in FIG. 29 , the alternative tear notch 51 may be formed by cutting or melting away material from the top cross-seal 39 .
[0079] FIG. 30 depicts the reclosable bag 38 in an opening condition. The notch 50 is separated by a tearing force produced by the user, allowing the tearing force to continue to the fin seal 35 of the bag along the top of fastener strip 14 . As the tearing force proceeds, the hindrance of the fin seal 35 is reduced by the lines of weakness 84 , 86 since the tearing force encounters a weakened layer of the fin seal 35 . The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0080] FIG. 31 depicts the reclosable bag 38 in an alternative opening condition using the tear notch 51 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force to continue along the top of the fastener 14 to the lines of weakness 84 , 86 . As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force encounters a weakened layer of the fin seal. The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0081] FIG. 32 depicts another alternative tear notch 100 formed in the top cross-seal 39 by cutting or melting away material in the cross-seal. FIG. 33 depicts the reclosable bag 38 in another alternative opening condition using the tear notch 100 . The notch 51 is separated by a tearing force produced by the user, thereby allowing the tearing force to continue along the top of the fastener 14 to the lines of weakness 84 , 86 . As the tearing force proceeds, the hindrance of the fin seal 35 is reduced since the tearing force encounters a weakened layer of the fin seal. The fastener 14 prevents the tear pattern from continuing down the length of the reclosable bag 38 and prevents the package from being destroyed. Once the tearing is complete, the flanges of the fastener strip 14 can be gripped by the user to open to the interior of the reclosable bag 38 .
[0082] Although the tear notch 100 is shown for the sixth embodiment of the present invention, the tear notch may be formed in the cross-seal 39 for the fourth and fifth embodiments of the present invention. The separation of the notch 100 , as described for FIG. 33 , would be similar for the areas of weakness described for the fourth and fifth embodiments.
[0083] Thus, the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.
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A method of making a reclosable plastic bag ( 38 ) having a fin seal ( 35 ) which provides a weakness area ( 23, 80, 81, 84, 86 ) that extends into at least one side of the fin seal ( 35 ). Perforation axes ( 19, 20 ) for opening the reclosable plastic bag ( 38 ) may be aligned with the weakness area ( 23, 80, 81, 84, 86 ). A reclosable bag ( 38 ) made in accordance with the method is also disclosed.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a shoe-wiping mat with color pattern for rent, having a novel taffeted texture. More specifically, the invention relates to a shoe-wiping mat with color pattern for rent, having vivid color pattern, excellent softness, dust-adsorbing property and dust-holding property, preventing undulation phenomenon on the mat surface even after used repetitively, and having excellent fitness to the floor surfaces.
2. Description of the Prior Art
Dust-control (shoe-wiping) mats have heretofore been widely used for preventing outdoor dust and dirt from entering into indoors adhering to the bottoms of the shoes. The dust-control mats are used on a rental basis; i.e., the mats are rented to a customer for a predetermined period of time, laid on a place such as porch through where people go in and out, recovered, washed, regenerated by the treatment with an oil or the like, and are rented again to the customers.
The rental mats include those of the separate type in which a mat with piles is detachably attached to a rubber frame-like base as disclosed in Japanese Patent Publication No. 7450/1984 and those of the unitary type in which a rubber sheet is fastened to the back side of the piled mat as disclosed in Japanese Patent Publication No. 7 213/1992. The latter mats, however, are now preferred owing to their stability when they are laid and appearance.
The shoe-wiping mats are used being laid on entrances of shops, hotels and offices. It has therefore been desired to provide shoe-wiping mats that draw attention and are fashionable, and there have been used shoe-wiping mats having color patterns using taffeta piles of a plurality of hues as taffeta.
The shoe-wiping mats with color pattern for rent have heretofore been produced by using taffeta piles of a plurality of hues and taffeting the base fabric by using such a device as MOQUETTE or WILTON. Of the plurality of colored pile yarns, those pile yarns that do not appear as piles on the surface necessarily exist as dead yarns. Therefore, the pile yarns are used wastefully, resulting in an increase in the cost of the mat and in the weight of the mat.
What is more important is that in the mats of this type in which dead yarns exist on the back surface (stitch surface) of the base fabric, the back surface becomes rugged to a conspicuous degree impairing smoothness. Besides, if it is attempted to improve fitness to the floor surface, the thickness of the backing of the elastomer must be increased.
Moreover, since the back surface of the base fabric has a nonhomogeneous texture and structure, the shoe-wiping mat with color pattern for rent is distorted and is undulated after it is used, washed and is regenerated repetitively. That is, the rental mat loses its commercial value, comfort for walking on it and dust-removing property.
That is, it would appear that the undulation disappears when the adhesion between the base fabric and the rubber is reinforced. In fact, however, the taffeted base fabric and the rubber sheet have radically different chemical compositions and physical properties. Therefore, dimensional difference easily occurs during the production, use or regeneration, and any inhomogeneity in the taffeted base fabric becomes a cause of undulation.
For instance, when the rubber sheet is heat melt-adhered to the base fabric of mat, the rubber sheet is elongated by the heat and then undergoes the contraction by the amount by which it is elongated after the production. Accordingly, a dimensional difference occurs between the two and turns out to be undulation. When washed, furthermore, the rubber does not contract but the base fabric contracts to develop a dimensional difference which is a cause of undulation. The dimensional difference similarly occurs even under the conditions in which it is used where the heat, light, vapor and water are acting thereto.
SUMMARY OF THE INVENTION
The object of the present invention therefore is to provide a shoe-wiping mat with color pattern for rent, having a novel taffeted texture and, particularly, to provide a shoe-wiping mat with color pattern for rent, having vivid color pattern, excellent softness, dust-adsorbing property and dust-holding property, preventing undulation phenomenon on the mat surface even after it is used repetitively, and having excellent fitness to the floor surfaces. According to the present invention, there is provided a shoe-wiping mat for rent comprising a base fabric, mat piles taffeted to the base fabric, and an elastomer backing applied to the non-pile surface of the base fabric, wherein a row of taffeta stitches in the direction of width of the base fabric is slightly tilted relative to the direction of width of the base fabric and is formed in a zig-zag shape from a folding point on one side to a folding point on the other side maintaining a predetermined distance in the direction of width and a small distance in the lengthwise direction, thereby to form a belt-like row of taffeta stitches which as a whole extends in the lengthwise direction of the base fabric, boundary lines connecting the folding points which are neighboring in the lengthwise direction of taffeta stitches are formed in a zig-zag shape having a pitch greater than the pitch between said folding points, the folding points of the belt-like row of taffeta stitches neighboring in the direction of width of the base fabric are positioned on common zig-zag boundary lines, the folding points of the belt-like row of one side are positioned at the centers of the folding points which are neighboring in the lengthwise direction of the belt-like row of the other side, mat piles have a plurality of mat pile surfaces of different hues the mat piles do not at all have dead yarns, and at least one unstitched portion exists between the neighboring mat pile surfaces of different hues.
In the shoe-wiping mat of the present invention, it is desired that the rows of taffeta stitches that are neighboring in the lengthwise direction are so formed as to have different sizes in order to form zig-zag boundary lines, and that an average width (W) between the folding points of taffeta stitches in the direction of width of the base fabric is from 10 to 200 mm and, particularly, from 20 to 80 mm, that the pitch (Ps) between the folding points in the lengthwise direction is from 1 to 30 mm and, particularly, from 3 to 20 mm, and that the size of deviation (Ws) in the direction of width is from 1 to 40 mm and, particularly, from 2 to 16 mm. It is further desired that the size of protrusion (Z) of the zig-zag boundary lines in the direction of width of the base fabric is from 1 to 40 mm and, particularly, from 5 to 25 mm, and the pitch in the lengthwise direction (Pz) is from 10 to 100 mm and, particularly, from 20 to 80 mm.
The shoe-wiping mat with color pattern for rent of the present invention comprises the base fabric, mat piles taffeted to the base fabric, and the elastomer backing applied to the non-pile surface of the base fabric, and a first feature resides in the double rows of taffeta stitches of the base fabric, that are forming a particular zig-zag structure.
That is, in the mat of the present invention, a row of taffeta stitches is slightly tilted relative to the direction of width of the base fabric and is formed in a relatively small zig-zag shape from a folding point on one side to a folding point on the other side maintaining a predetermined distance in the direction of width and a small distance in the lengthwise direction, thereby to form a belt-like row of taffeta stitches which as a whole extends in the lengthwise direction of the base fabric, and boundary lines connecting the folding points which are neighboring in the lengthwise direction of taffeta stitches are formed in a zig-zag shape having a pitch greater than the pitch between said folding points creating the double zig-zag structure.
To explain the arrangement and size of the double zig-zag structure of taffeta stitches of the present invention, FIG. 3 illustrates a basic recurring unit of the rows of taffeta stitches, and wherein X represents the direction of width and Y represents the lengthwise direction.
First, the stitches consist of unit rows 10a and 10b which are continuous in series maintaining a small distance. The unit row 10a(10b) is slightly tilted in the direction X of width of the base fabric, and is formed in a zig-zag shape from a folding point 11a(12a) on one side to a folding point 12a(12b) on the other side maintaining a predetermined distance (W+Ws/2; W is an average size in the direction of width and Ws is a size of deviation of small zig-zag shape in the direction of width) in the direction X of width and maintaining a small distance (Ps/2; Ps is a pitch of small zig-zag shape in the lengthwise direction) in the lengthwise direction, forming a belt-like row 13A of taffeta stitches which, as a whole, extends in the lengthwise direction of the base fabric.
Boundary lines 14(15) connecting the neighboring folding points 11a, 11b, 11c, . . . (12a, 12b, 12c, . . . ) of taffeta stitches in the lengthwise direction are forming zig-zag boundary lines having a pitch Pz in the lengthwise direction which is greater than the pitch Ps between the folding points in the lengthwise direction and having a size of protrusion Z in the direction of width. That is, the unit row 10a of taffeta stitches is longer than the unit row 10b, which gives a size of deviation Ws of a small zig-zag shape and, consequently, gives the pitch Pz of a large zig-zag shape in the lengthwise direction and the size of protrusion Z in the direction of width.
A dimensional relationship of unit rows 10a and 10b of taffeta stitches is inverted at given folding points. The inverting positions, i.e., the folding positions of the large zig-zag shape 14 are n-th positions as counted from the start point, where n is a number satisfying the following formulas (1) and (2),
n=Z/Ws (1)
n=Pz/2Ps (2)
In the embodiment shown in FIG. 3, the folding point 11d corresponds thereto.
The belt-like row 13A of taffeta stitches is formed in a side-by-side relationship in the direction X of base fabric relative to the right and left neighboring belt-like rows 13B and 13C, the folding points of the belt-like rows 13B, 13C of taffeta stitches which are neighboring in the direction X of width of the base fabric are positioned on the common zig-zag boundary lines 14, 15, and the folding points 16a, 16b, . . . (17a, 17b, . . . ) of the belt-like rows 13B(13C) of the neighboring sides are positioned at the centers of the neighboring folding points 11a, 11b, . . . (12a, 12b, . . . ) in the lengthwise direction of the belt-like row 13A of the side that serves as a reference. That is, the belt-like rows 13A, 13B, 13C of taffeta stitches which are neighboring in the direction X of width of the base fabric are in phase in regard to the pitch Pz of the large zig-zag shape but are out of phase by 1/2 in regard to the pitch Ps of the small zig-zag shape.
According to the present invention which employs the above-mentioned taffeta stitch texture, the mat is prevented from being deviated when it is laid on the floor and is, further, effectively prevented from developing undulation when it is used, washed and is regenerated repetitively.
The deviation in position of the mat which is a problem in the present invention is a phenomenon in which when people walk treading on the mat laid on the inlet, the mat is slightly deviated in position from where it is laid on the floor surface due to the pressure of when it is trod and the release of pressure. This stems from the fact that the mat piles that are implanted have a directivity. To eliminate such a positional deviation, therefore, it is important to eliminate the directivity of implantation.
The mat of the present invention has taffeta stitches that constitute two large and small zig-zag structures in the lengthwise direction of the base fabric of the mat and, further, constitute wedge-like structure in both directions in the direction of width of the base fabric of the mat. Due to the zig-zag structures and wedge-like structure of the taffeta stitches, therefore, there is obtained a restoring force which prevents the mat from moving in any direction, and the mat is prevented from being deviated in position.
In addition to the combination of the zig-zag structures and wedge-like structure of the taffeta stitches, furthermore, the folding points of the belt-like rows of taffeta stitches that are neighboring in the direction of width of the base fabric are positioned on the common zig-zag boundary lines, and the folding points of the belt-like row on one side are located at the centers of the folding points that are neighboring in the lengthwise direction of the belt-like row of the other side, whereby the taffeta stitches exist in a random fashion and uniformly as a whole, the residual stress is dispersed when the mat is used, washed and regenerated repetitively, and occurrence of undulation is effectively prevented.
In the shoe-wiping mat of the present invention, the mat piles have a plurality of mat pile surfaces of different hues to impart its own ornamental effect and fashionableness. Here, a distinguished feature resides in that the mat piles do not at all have dead yarns, and at least one unstitched portion exists between the neighboring mat pile surfaces of different hues.
That is, at least one unstitched portion is present between the neighboring mat pile surfaces of different hues, making it possible to effectively prevent the mat piles of different hues from mixing in the boundary portion of the mat pile surfaces and, hence, to form a vivid and clear pattern on the surface of the mat.
In the shoe-wiping mat of the present invention having a multi-color pattern, furthermore, the mat piles do not include any dead yarn; i.e., the yarns are all used for forming the mat piles. It is therefore made possible to save the amount of the yarns and to uniformalize the texture of mat piles on the upper surface of the base fabric, presenting distinguished effects from the standpoint of softness and the feel of the piles, dust-adsorbing property and dust-holding property, and preventing undulation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view which schematically illustrates a shoe-wiping mat with color pattern for rent according to the present invention;
FIG. 2 is a plan view illustrating, on an enlarged scale, the stitched surface of the base fabric of the shoe-wiping mat of the present invention;
FIG. 3 is a diagram explaining the arrangement and size of a double zig-zag structure of taffeta stitches according to the present invention; and
FIG. 4 is a diagram illustrating the structure of taffeta stitches of a sample B used in the example.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a sectional view which schematically illustrates the shoe-wiping mat with color pattern for rent according to the present invention, and FIG. 2 is a plan view illustrating, on an enlarged scale, the stitched surface of a base fabric of the mat.
The shoe-wiping mat with color pattern for rent of the present invention comprises a base fabric 1, mat piles 2 taffeted on the base fabric, and an elastomer backing 3 applied to the non-pile surface of the base fabric. Taffeta stitches 4 exist on the back surface of the base fabric 1.
Pile patterns 5a, 5b, 5c, . . . having different hues exist on the mat pile surface of the shoe-wiping mat. At least one unstitched portion 6 exists in the boundary of the pile patterns. According to the present invention, the mat piles 2 are all taffeted to the base fabric 1 at a predetermined driving density, and there exist no dead yarn or yarn that extends in parallel with the base fabric in excess of a predetermined stitch length.
The basic pattern (taffeta stitch texture) of the row of taffeta stitches 4 of FIG. 2 was described in detail with reference to FIG. 3, and it should be noted that the unstitched portion 6 exists between the pile patterns of different hues not only in the direction of width of the base fabric but also in the lengthwise direction of the base fabric.
In the shoe-wiping mat of the present invention, it is desired that the average width (W) between the folding points of the rows 10a and 10b of taffeta stitches 4 in the direction of width of the base fabric is from 10 to 200 mm and, particularly, from 20 to 80 mm from the standpoint of taffeting the mat piles and of preventing the position deviation and undulation of the mat. From the same point of view and of selecting a proper taffeting density, furthermore, it is desired that the pitch (Ps) between the folding points in the lengthwise direction is from 1 to 30 mm and, particularly, from 3 to 20 mm, and the size of deviation (Ws) in the direction of width is from 1 to 40 mm and, particularly, from 2 to 16 mm.
It is further desired that the size of protrusion (Z) of the zig-zag boundary line in the direction of width of the base fabric is from 1 to 40 mm and, particularly, from 5 to 25 mm and that the pitch (Pz) in the lengthwise direction is from 10 to 100 mm and, particularly, from 20 to 80 mm from the object of the present invention. When Z is smaller than the above-mentioned range or when Pz is larger than the above-mentioned range, only small effect is obtained for preventing the position deviation of the mat and for preventing undulation. In the opposite case, taffeting efficiency decreases.
The shoe-wiping mat of the present invention is taffeted by using an apparatus for producing patterned and taffeted products disclosed in Japanese Laid-Open Patent Publication No. 5014 62/1986 and by controlling the taffeted pattern as described above. In this production apparatus, yarns having different colors are arbitrarily and selectively fed to the opener (taffeting needle) for the base fabric, a taffeting needle is corresponded to each belt-like row, and the taffeting needle is scanned and the yarns are fed in a controlled manner as described above. This control is easily performed by setting a pattern to a control computer in advance.
As the base fabric, there can be used woven fabrics and nonwoven fabrics of a variety of fibers. As the woven fabric, there can be used a plain woven fabric or a modified woven fabric obtained by weaving spun yarns or multi-filament yarns. As the nonwoven fabric, on the other hand, there can be used those of the spun-bonded type, melt-blown type or heat melt-adhered type. The base fabric may be comprised of any synthetic fibers such as polyester fibers, polyamide fibers, acryl fibers or ultra-high molecular polyolefin fibers. Most desirably, however, the base fabric should be comprised of a high molecular thermoplastic polyester and, particularly, a thermoplastic copolyester composed chiefly of polyethylene terephthalate or ethylene terephthalate.
It is desired that the weight of the base fabric is, generally, from 50 to 500 g/m 2 and, particularly, from 100 to 400 g/m 2 though it may vary depending upon the weight of the mat.
As the base fabric having particularly excellent property for preventing undulation, there can be used a plain woven fabric of flat slit yarns (film yarns) of a drawn polyester film. As the mat piles having excellent erecting property, furthermore, there can be used a base fabric obtained by needle-punching a floss-like synthetic fiber to the plain woven fabric of flat slit yarns of the drawn polyester film. The flat slit yarns are obtained by slitting a forcibly drawn polyester film having a thickness of from 10 to 5000 μm to have a width of from about 2 to about 25 mm. Though the above-mentioned synthetic fibers can be all used as the floss-like synthetic fibers, it is desired to use the polyester fibers. The floss-like fibers are obtained by superposing a fiber web formed by carding or the like on both sides of the woven fabric, and causing the fibers to be entangled by one another. The single fiber may have a thickness of from about 1 to about 20 deniers.
As the pile yarns to be driven into the base fabric, there can be used spun yarns or multi-filament yarns consisting of one or two or more kinds of cotton fibers, rayon fibers, polyvinyl alcohol fibers, acryl fibers, nylon fibers and any other synthetic fibers. It is desired that the mat piles are multi-filament yarns or spun yarns of nylon fibers or acryl fibers. The pile yarns can be implanted, i.e., taffeted by the above-mentioned means. Moreover, the mat pile yarns may be curled or uncurled, and the pile length may be the same or different.
Generally, it is desired that the mat pile yarns have a thickness of from 300 to 10000 deniers/yarn and, particularly, from 1000 to 10000 deniers/yarn, has a number of twists of from 50 to 500 turns/m and, particularly, from 100 to 300 turns/m, and have a pile length of from 3 to 20 mm and, particularly, from 5 to 15 mm. It is further desired that the mat piles are driven into the base fabric in a number of from 3 to 20 piles/inch and, particularly, from 5 to 14 piles/inch (from 1.97 to 5.5 piles/cm).
The shoe-wiping mat of the present invention can be adapted to either a unitary mat that does not require any particular underlay (base) or to a separate mat that requires the underlay. In the former case, the rubber sheet is formed together with the base fabric to for a backing and in the latter case, a rubber latex is applied to form a thin rubber backing layer.
As the rubber that serves as the backing, there can be used a variety of elastomer polymers such as nitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), polybutadiene (BR), polyisoprene (IIB), butyl rubber, natural rubber, ethylene-propylene rubber (EPR), ethylene-propylene-diene rubber (EPDM), polyurethane, chlorinated polyethylene, chlorinated polypropylene, soft vinyl chloride resin and the like. From the standpoint of resistance against oils and weatherability, it is desired to use the nitrile-butadiene rubber (NBR). In forming the rubber backing, it is allowed to blend widely known blending agents such as sulfur or organic curing agent, cure promoting agent, softening agent, anti-aging agent, filler, dispersant, plasticizer, coloring agent and the like agents in known amounts.
In forming a mat as a unitary structure, the above-mentioned rubber composition is kneaded using a roll, Bumbury's mixer or the like. The composition is then molded into a sheet and on which is then placed a taffeted mat. The laminate is then heated and pressurized in a pressurizing mold to effect the adhesion and curing simultaneously. To increase the adhesion between the rubber sheet and the base fabric, the non-pile surface of the base fabric may be coated with a rubber latex of the same kind as the rubber sheet. Or, an adhesive agent such as an ethylene acet ate/vinyl copolymer or an adhesion promoting agent may be applied thereto in advance. It is desired that the weight of the rubber sheet lies within a range of from 100 to 3200 g/m 2 , and the rubber sheet and the base fabric are adhered together as a unitary structure in such a manner that the edges of the rubber sheet slightly protrude outwardly beyond the edges of the base fabric. The adhesion by curing is better carried out at a temperature of from 90° to 200° C. under a pressure of from 0.5 to 10 kg/cm 2 .
When a soft vinyl chloride resin is used as the rubber sheet, a plastic sol of the vinyl chloride resin is applied to the non-pile surface of the pile-implanted base fabric and, then, the plastic sol layer of the vinyl chloride resin is gelled upon heating. When a polyurethane is used as the rubber sheet, a two-can type polyurethane resin composition is applied to the non-pile surface of the pile-implanted base fabric and is then cured upon heating or the like.
The backing of the separate mat is formed by applying a latex of the above-mentioned elastomer followed by drying or curing. The curing can be effected under normal pressure at the above-mention ed temperature.
It is desired that the elastomer backing has a thickness of, generally, from 0.01 mm to 3 mm and, particularly, from 0.1 to 2.5 mm. When the thickness is relatively as small as 0.5 mm or less, the elastomer backing can be used in combination with the mat base. When the thickness is not smaller than 0.5 mm, the elastomer backing can be used by itself as a unitary mat.
The pile yarns of the mat of the present invention adsorb and hold dust adhered to the bottoms of the shoes. To further enhance this action, the pile yarns may be coated or impregnated with a dust-adsorbing oil. As the dust-adsorbing liquid, there can be used mineral oils such as fluidized paraffin, spindle oil, alkylbenzene oil, diester oil and castor oil, or such oils as synthetic oils or plant oils, or aqueous dust-adsorbing agent as disclosed in Japanese Patent Publications Nos. 1019/1978 and 37471/1978. Usually, the adsorbing agent may be applied in an amount of from 0.1 to 200 g/m 2 .
EXAMPLES
The invention will now be described in further detail by way of the following Examples.
Example 1
______________________________________BCF nylon: 9 stitches/inch gauge 1/10 pile length 9 mm weight 1700 g/m.sup.2 cut pileBase fabric: polyester plain woven fabric 150 g/m.sup.2 *polyester cotton 100 g/m.sup.2 Total 250 g/m.sup.2______________________________________
The polyester cotton was punch-worked using a needle.
The samples A and B were prepared by the following driving design.
The samples A and B were so set as to have the same number of taffetas/inch.
Sample A: linear taffetas
Sample B: shown in FIG. 4
The above-mentioned starting fabric was coated with the latex followed by drying at 175° C. for 15 minutes, and was cured together with an uncured rubber sheet that was cut into a size of 70×85 cm having a thickness of 1.8 mm under the conditions of a temperature of 170° C. for 15 minutes under a pressure of 5 kg/cm 2 .
The mat was laid for three days on a place where 3000 people walk through a day and was then washed. This was repeated 40 times to measure the degree of contraction of the mat and the occurrence of undulation.
TABLE 1______________________________________ Item A B______________________________________Lengthwise Coefficient contracted 1.3%direction of contraction by 2.8% Undulation 10 mm × 5 0 .sup.Direction Coefficient contracted 1.4%of width of contraction by 1.4% Undulation 10 mm × 4 0 .sup.______________________________________
As is obvious from Table 1, the sample A having a linear weaving direction is greatly contracted in the lengthwise direction and the mat as a whole undulated. On the other hand, the sample B uniformly contracted in both the direction of width and lengthwise direction, and was neither locally contracted nor undulated, and could be favorably used.
According to the present invention which employs a particular taffeta stitch texture of a double zig-zag structure, it is allowed to prevent the positional deviation of the mat that is used being laid on the floor, and occurrence of undulation is effectively prevented even when the mat is used, washed and regenerated repetitively.
That is, in the taffeta-stitched mat of the present invention, there exist two large and small zig-zag structures in the lengthwise direction of the base fabric of the mat, and the wedge-like structure exists in both directions in the direction of width of the base fabric of the mat. Due to the zig-zag structure and wedge-like structure of taffeta stitches, therefore, there is obtained a restoring force that prevents the mat from moving in any direction, and the mat is prevented from being deviated in position.
In addition to the combination of the zig-zag structure and the wedge-like structure of taffeta stitches, furthermore, the folding points of the belt-like row of taffeta stitches neighboring in the direction of width of the base fabric are positioned on common zig-zag boundary lines, and the folding points of the belt-like row of one side are positioned at the centers of the folding points which are neighboring in the lengthwise direction of the belt-like row of the other side. Therefore, the taffeta stitches as a whole exist in a random fashion and uniformly, and the residual stress is dispersed when the mat is used, washed and regenerated repetitively, and occurrence of undulation is effectively prevented.
In the shoe-wiping mat of the present invention, furthermore, the mat piles have a plurality of mat pile surfaces of different hues to impart its own ornamental effect and fashionableness. Here, however, the mat piles do not at all include dead yarn, and at least one unstitched portion exists between the neighboring mat pile surfaces having different dues, offering the following distinguished advantages.
That is, with at least one unstitched portion being interposed between the neighboring mat pile surfaces of different hues, the mat piles having different hues are effectively prevented from being mixed in the boundary portion of the mat pile surfaces, and it is allowed to form a vivid and clear pattern on the surface of the mat.
In the shoe-wiping mat having multi-color pattern of the present invention, furthermore, the mat piles do not at all contain dead yarn and the yarns are all used for forming the mat piles, making it possible to save the amount of the yarns, to uniformalize the mat pile texture on the base fabric, and offering distinguished effects in regard to softness and the feel of the piles, dust-adsorbing property, dust-holding property, and preventing undulation.
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A shoe wiping mat with color pattern for rent, having a novel taffeted texture and vivid color pattern, excellent softness, dust-adsorbing property and dust-holding property, preventing undulation phenomenon on the mat surface even after repetitive use, and having excellent fitness to floor surfaces, resulting from the tilt of the stitches, zig-zag shape stitches and boundary lines, pitch of the stitches and position thereof.
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Patent (unknown) which issued (unknown) which corresponds to U.S. application Ser. No. 09/616,486 filed Jul. 14, 2000 and claims the benefit of U.S. Provisional Application No. 60/215,515 entitled Modular School filed Jun. 30, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of building construction and, in particular, to a modular system for assembling school buildings.
[0004] 2. Description of the Related Art
[0005] School construction has typically proceeded in a manner very similar to that of traditional residential home construction. An architect first drafts a set of plans for the building. The plans are then checked and approved by the client and the responsible regulatory agency. The design, drafting, and approval process typically takes a year or so, particularly as changes are often required by the client or the approval entity. Once the plans are approved, the actual construction of the building takes place, commencing typically with preparing the building site by clearing and leveling the land. The foundation is then prepared, the frame of the building is erected, covering material is applied to the interior and exterior of the building, and the interior flooring and windows and door are installed. Plumbing and electrical wiring are also installed along with increasingly common telephone and high-speed communication lines.
[0006] While ground up construction offers the advantage that a school can be thereby designed and built specifically for the requirements of a particular building location and client, this specificity incurs significant costs in architect's and approval fees and time. The typical duration for building a traditional permanent school is four years from inception to completion. With the rapidly changing populations, particularly of school age children, that many portions of the country are experiencing, a four year lag time from request to build a new school building until it is ready for use imposes a significant burden to the schools and the children using them.
[0007] As an alternative to site assembled permanent structures, partially premanufactured school buildings are sometimes used. The portable buildings may be single structures, similar to mobile homes, or more typically, consist of two structures, each enclosed on three sides with one open wall that are joined together at the open walls to form single structures. The partially preassembled buildings, typically referred to as “portables”, are placed on a foundation pad. Plumbing, electrical wiring, telephone lines, and heating, ventilation and air conditioning (HVAC) systems are installed. Portables are available in standard sizes and typically come with insulation, exterior wall finishing, and roofs already included.
[0008] In order to be portable, the structure and materials of the portable buildings are typically lightweight and the size of the structure is such as to fit under overpasses and bridges over roads. While convenient, the lightweight construction and size of portables presents several drawbacks to their use as school buildings. They generally employ a limited amount of insulation in the walls and roof and are often placed directly on a wood foundation. Thus, the insulative capabilities of a portable are generally lower and the associated heating and cooling costs are generally higher than for a better-insulated permanent building of comparable size. In addition, the light structure and the typical manner of joining the two separate sections of typical portables makes the portable buildings not as structurally durable over time. They tend to develop creaky floors and windows and doorframes that distort and make the opening and closing of the windows and doors problematic. The joint between the two sections of the portable is a potential source of drafts, dirt, and pests and also structural flexing.
[0009] The requirement for a portable to fit under overpasses and bridges means that, in practice, the overall height of a typical portable is limited to approximately 12 feet. The ceilings and corresponding roofs are also typically flat in order to simplify construction. The footprint of a portable building is typically constrained by the standard sizes of portables available. With a limited footprint and a ceiling that is typically no more than 9 feet high, the interior volume of a portable building is limited. This can become a concern, because a school classroom building often contains 30 or more children and adults all of who require clean air to breathe and who generate carbon dioxide as they exhale. Excessive concentration or accumulation of carbon dioxide, dust, pollen, particulates, or noxious vapors are a known health hazard, particularly around children. The limited volume of air per person of a portable building places significant demands on the building's HVAC system to provide fresh air to the inhabitants.
[0010] Another disadvantage of typical portables is the flat roof profile itself. The lack of a pitch to the roof profile allows a significant amount of snow, rainwater, dirt, and debris to accumulate on the rooftop. This imposes a significant weight load on the roof. In areas with significant snowfall, the use of buildings with flat roofs is often precluded. In addition, accumulated water and debris can attack the roofing materials leading to leaks in the roof appearing prematurely.
[0011] Also, since the roof is generally multi-layered, a leak in the outer layer will allow water to ingress, however the water may migrate laterally within the layers of a flat roof so that a water leak into the interior of the building is not necessarily immediately below the external break in the roofing material. This makes locating a leak source and repairing it more difficult.
[0012] The flat roof of a typical portable is typically separated from the interior ceiling by rafter structures and insulation material with a thickness on the order of 1 foot. The outer roof of the portable is exposed to thermal heating from the sun and cooling from exposure to the ambient air. It can be appreciated that the thermal insulation factor of a portable with a flat roof surface in relative proximity to the interior ceiling is inferior in comparison to that of a permanent structure with a pitched roof profile and an enclosed dead air space between the roof surface and the interior ceiling surface, assuming comparable insulation materials in the two structures. In practice, a permanent structure with an upper roof displaced from the ceiling provides additional space for dedicated insulation material in comparison to a portable with the upper roof and the ceiling positioned adjacent each other.
[0013] Many portable building designs lack provision for securely fastening the building to the foundation. A secure attachment is required to inhibit uplift of the building from the foundation in case of a seismic event or high wind conditions. The anchoring methods utilized by many portable designs incorporates metal strapping or anchors shot into the foundation that are typically not strong enough to inhibit building uplift in an extreme stress event.
[0014] It can be appreciated that there is an ongoing need for a system to provide permanent, structurally sound school buildings in a reduced time frame. The system should provide a pitched roofline to facilitate shedding rain, snow, and debris and increased interior volume for a given floor area. However, the system should also be configured to be able to be transported over the road from the manufacturing facility to the building site in a substantially preassembled condition to reduce the time of construction. The system should provide a manner of securely fastening the structure to the foundation to provide increased strength in earthquake and extreme weather.
SUMMARY OF THE INVENTION
[0015] The aforementioned needs are satisfied by the modular school building system of the present invention. In one aspect, the modular school building system is a preassembled steel rigid building frame comprising a roof portion extensible between a first, flat configuration and a second, pitched configuration. The roof portion comprises a pivotable roof section and a slidable roof section wherein the pivotable roof portion and the slidable roof portion are pivotably attached. In one embodiment, pivotably attached comprises joining the pivotable roof section and the slidable roof section with a plurality of hinges. The modular school building system also comprises a lift adapted to move the frame from the flat configuration to the pitched configuration. The frame in the flat configuration is sized so as to fit under standard highway overpasses and bridges when the frame is loaded onto a standard low flatbed trailer. The modular school building system further includes anchor assemblies adapted to secure the frame to a building foundation.
[0016] In another aspect, the invention is a system for constructing buildings with a modular preassembled frame with a roof portion movable between a flat and a pitched position. The system includes a lift assembly that moves the roof portion between the flat position and the pitched position and anchor assemblies that secure the frame to a building foundation. The system also includes a plurality of fastening devices that secure the modular frame in the flat and in the pitched positions. The system in the flat position is sized so as to fit under standard highway overpasses and bridges and is thereby transportable over the road.
[0017] The system is used to construct a permanent structure by: transporting a plurality of modular frames to a building site; placing the plurality of modular frames on a prepared foundation with anchor assemblies installed therein; interconnecting the plurality of modular frames; interconnecting the modular frames to the prepared foundation with the anchor assemblies; moving the modular frames to the pitched position with the lift assembly; and installing preassembled interior wall assemblies. Known finishings materials such as exterior wall covering, roofing, plumbing, electrical and telephone wiring, HVAC system, and floor coverings are then installed to complete a permanent structure.
[0018] The region defined between the upper roof in the pitched configuration and the collar creates a dead air space that both increases the insulative properties of the completed building and provides a reservoir of air to reduce the demands on the HVAC system.
[0019] These and other objects and advantages of the present invention will become more fully apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] [0020]FIG. 1 is an isometric view of a frame module of the modular school building system in the pitched configuration;
[0021] [0021]FIG. 1A is a close-up view of the slotted portion of the slidable roof section;
[0022] [0022]FIG. 1B is a close-up isometric view of a pivot assembly of the pivotable roof section;
[0023] [0023]FIG. 1C is a close-up isometric view of the pivoting connection of the pivotable and slidable roof sections;
[0024] [0024]FIG. 2 is a detail side view of the slidable roof section and slot in the flat configuration;
[0025] [0025]FIG. 3 is a detail side view of the slidable roof section and slot in the pitched configuration;
[0026] [0026]FIG. 4 is a section view of the upper roof secured in the pitched position;
[0027] [0027]FIG. 5 is an end, section view of the pivot assembly or guide pin assembly portion of the upper roof;
[0028] [0028]FIG. 6 is a section view of a typical anchor assembly set in a foundation footing and connected to the frame module;
[0029] [0029]FIG. 7 is a section view of the modular school building system with a typical anchor assembly set in a foundation footing, connected to a frame module, and with the foundation floor slab in place;
[0030] [0030]FIG. 8 is a section view of a typical interior wall assembly;
[0031] [0031]FIG. 9 is an isometric view of three frame modules interconnected together and also anchored to the foundation;
[0032] [0032]FIG. 9A is a detail of a lower outside corner of a frame module; and
[0033] [0033]FIG. 10 is an isometric view of a frame module in the flat configuration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Reference will now be made to the drawings wherein like numerals refer to like parts throughout. FIG. 1, along with details A, B, and C are isometric views of a modular school building system 100 comprising a frame module 102 . The modular school building system 100 provides a substantially preassembled and preapproved design for constructing a permanent school building with a pitched roof. The modular school building system 100 is transportable over the road on standard trucks.
[0035] The frame module 102 of this embodiment is generally rectangular and constructed of steel c-channels and comprises a collar 112 and an upper roof 104 . The upper roof 104 is movable between a pitched configuration 114 illustrated in FIG. 1 and a flat configuration 116 illustrated in FIG. 10. The pitched configuration 114 provides a sloping roof profile to the frame module 102 so that, when the frame module 102 is connected with other frame modules 102 and provided with other materials to comprise a completed building in a manner that will be described in greater detail below, the roof of the completed building has a pitch.
[0036] The pitched roof provided by the modular school building system 100 better sheds rain, snow, and dirt thereby making the modular school building system 100 suitable for regions of the country that are not suitable for standard portables. The pitched roof also provides longer mean life for the roofing materials because dirt, water, and snow will not as readily accumulate on the roof surface. The pitched roof profile further provides a dead air space within the cavity defined under the pitched roof to thereby improve the insulation factor of a building employing the modular school building system 100 particularly with respect to the thermal heating from incident sunlight.
[0037] The flat configuration 116 reduces the overall height of the frame module 102 compared to the pitched configuration 114 to thereby facilitate transportation of the frame module 102 in a manner that will be described in greater detail below. By enabling the modular school building system 100 to be readily transported over the road, the modular school building system 100 can be substantially preassembled at a remote manufacturing facility and transported to the building site. By facilitating manufacturing the modular school building system 100 at a dedicated remote site, the modular school building system 100 obtains the advantages of better dimensional uniformity of the frame modules 102 , more reliable interconnection and alignment of the component pieces, and greater economy of scale as will be appreciated by one skilled in the art. By providing preapproved and preassembled frame modules 102 , the modular school building system 100 reduces the time and expense necessary to construct school buildings as compared to ground up, custom construction because much of the construction is already done before the customer receives the modular school building system 100 and the lengthy plan approval process has already been performed.
[0038] The frame module 102 defines an x axis 120 , a y axis 122 orthogonal to the x axis 120 , and a z axis 124 orthogonal to both the x 120 and the y 122 axes as shown in FIG. 1. It should be understood that references to the x 120 , y 122 , and z 124 axes hereinafter maintain the same orientation illustrated in FIG. 1.
[0039] The upper roof 104 comprises a pivotable roof section 106 and a slidable roof section 110 . The pivotable roof section 106 and slidable roof section 110 are generally rectangular and made of steel c-channel elongate members. The pivotable roof section 106 and slidable roof section 110 permit the frame module 102 to assume the pitched configuration 114 and the flat configuration 116 in a manner that will be described in greater detail below.
[0040] The pivotable roof section 106 and slidable roof section 110 are each comprised of two rafters 126 , a plurality of cross-ties 130 , and two end pieces 132 . The rafters 126 , cross-ties 130 , and end pieces 132 are elongate members made of steel c-channel. The rafters 126 , cross-ties 130 , and end pieces 132 , when interconnected, provide the structure and physical strength of the pivotable roof section 106 and the slidable roof section 110 . A first end 134 and a second end 136 of each rafter 126 is attached to an end of an end piece 132 so as to form a generally rectangular, planar assembly. The plurality of cross-ties 130 are attached to the rafters 126 so as to extend from one rafter 126 to the other rafter 126 in a generally perpendicular manner along the y axis 122 . The cross-ties 130 are disposed between the rafters 126 and the end pieces 132 so as to accommodate the installation of standard size roof substrate materials. By facilitating the use of standard size roof substrate materials, the modular school building system 100 further reduces the time and cost of constructing school buildings employing the modular school building system 100 .
[0041] In this embodiment, attaching the rafters 126 , end pieces 132 , and cross-ties 130 together comprises welding. It should be appreciated that the attachment can also comprise connecting fasteners, adhesives, clinching, press fits, or other methods or materials for joining materials well known in the art.
[0042] The first ends 134 of the rafters 126 are cut on a bias, which in this embodiment is approximately 19° from square as shown in FIG. 1, Detail 1 C, and FIG. 4. The first ends 134 of the rafters 126 of the pivotable roof section 106 and slidable roof section 110 are positioned adjacent each other and substantially coplanar and pivotably connected so as to form the upper roof 104 . In this embodiment, pivotably connecting the pivotable roof section 106 and slidable roof section 110 comprises joining the pivotable roof section 106 and slidable roof section 110 with a plurality of hinges 140 of a known type. In this embodiment, the hinges 140 are attached to the pivotable roof section 106 and slidable roof section 110 via welding.
[0043] The plurality of hinges 140 joining the adjacent pivotable roof section 106 and slidable roof section 110 allow the pivotable roof section 106 to pivot about the y axis 122 with the slidable roof section 110 . The approximately 19° bias cut of the first ends 134 of the rafters 126 provide clearance to thereby allow the pivotable roof section 106 and slidable roof section 110 to move so as to form an approximately 142° included angle, thereby forming the pitched configuration 114 of the upper roof 104 . The pitched configuration 114 of this embodiment is approximately a 4 in 12 pitch. The 4 in 12 pitch of the modular school building system 100 is known by those skilled in the art to provide an advantageous roof profile for shedding rain, snow, dirt and creating a dead air space under the roof profile.
[0044] The collar 112 is generally rectangular and approximately 12′ by 40′. The collar 112 is made from steel c-channel elongate members. The collar 112 provides a horizontal, planar load bearing structure for the frame module 102 extending along the x 120 and y 122 axes and provides an attachment surface for finishing materials such as ceiling panels and insulation. The collar 112 comprises two ridge beams 142 , a plurality of cross-ties 130 , and two end pieces 132 . An end of each perimeter beam 142 is attached to an end of an end piece 132 so as to form a generally rectangular, planar assembly. The plurality of cross-ties 130 are attached to the ridge beams 142 so as to extend from one perimeter beam 142 to the other perimeter beam 142 in a generally perpendicular manner along the y axis 122 . The cross-ties 130 are disposed between the ridge beams 142 and the end pieces 132 so as to be approximately equidistantly spaced between the end pieces 132 .
[0045] The frame module 102 also comprises vertical supports 144 a - d , an outer wall sill 146 , end sills 150 , and anchor stubs 152 . The vertical supports 144 , outer wall sill 146 , end sills 150 , and anchor stubs 152 are made from {fraction (3/16)}″ steel square tube, 4″ by 4″ in this embodiment. The vertical supports 144 are elongate members that are approximately 10′ long and support and elevate the collar 112 and the upper roof 104 . The outer wall sill 146 is an elongate member approximately 40′ long and the end sills are elongate members approximately 12′ long. An upper end 154 of each vertical support 144 a - d is attached to a corner 158 of the collar 112 so as to extend along the z axis 124 . A lower end 156 of the vertical supports 144 c and 144 d is attached to an end of the outer wall sill 146 . The lower end 156 of each vertical support 144 a - d is connected to an end of an end sill 150 . The vertical supports 144 a - d , the outer wall sill 146 , and the end sills 150 are interconnected so that the vertical supports 144 a - d extend along the z axis 124 , the outer wall sill 146 extends along the x axis 120 , and the end sills 150 extend along the y axis 122 , thereby defining the rectangular frame module 102 with the collar 112 and the upper roof 104 . In this embodiment, the attachment comprises welding.
[0046] The anchor stubs 152 are approximately 3′ long in this embodiment and provide attachment points for securing the anchor stubs 152 and thereby the frame module 102 to anchor structures set in a building's foundation to thereby anchor the frame module 102 against uplift and horizontal movement with respect to the foundation. A first end 160 of each anchor stub 152 is attached to the lower end 156 of the vertical supports 144 a and 144 b so that the anchor stubs 152 extend along the x axis 120 and further so that second ends 162 of the anchor stubs 152 are proximal.
[0047] The interconnection of the collar 112 , the vertical supports 144 , the outer wall sill 146 , the end sills 150 , and the anchor stubs 152 provides a rigid structure that can be readily moved about from the place of manufacture to the work site and at the work site. Thus, the modular school building system 100 can employ the advantages of preassembled structures previously described.
[0048] The frame module 102 also comprises pivot assemblies 160 and guide pin assemblies 162 as shown in FIGS. 1, 2, 3 , and 5 . The pivot assemblies 160 and guide pin assemblies 162 locate and secure the pivotable roof section 106 and the slidable roof section 110 to the collar 112 . The pivot assemblies 160 and guide pin assemblies 162 comprise a bracket 164 and a pin 166 . In this embodiment, the bracket 164 is an “L” shaped piece formed from ½″ steel plate and is approximately 7″×6″×3″. The pin 166 of this embodiment is a ⅝″ high strength bolt and corresponding nut of a known type extending along the y axis 122 . A bracket 164 is attached to each corner 158 of the collar 112 extending upwards.
[0049] Each bracket 164 and the second ends 136 of the rafters 126 of the pivotable roof section 106 are provided with a hole 170 . The hole 170 provides clearance for the pin 166 to pass through, which in this embodiment, is approximately ⅝″ in diameter. The pin 166 passes through the holes 170 and thus through the rafters 126 and the bracket 164 along the y axis 122 . Thus the pins 166 secure the rafters 126 and thus the pivotable roof section 106 during erection of the upper roof 104 to the brackets 164 and thus the collar 112 so as to restrict lateral translation of the pivotable roof section 106 along the x 120 , y 122 , and z 124 axes and also so as to restrict rotation about the x 120 and z 124 axes, but so as to permit rotation about the y axis 122 .
[0050] The second end 136 of the rafters 126 of the slidable roof section 110 are provided with reinforcement plates 172 and slots 174 as shown in FIGS. 2 and 3. The reinforcement plates 172 of this embodiment are ¼″ steel plate approximately 3″×16″ and are welded to the rafters 126 of the slidable roof section 110 adjacent the second end 136 . The reinforcement plates 172 provide increased structural strength to the rafters 126 to support the upper roof 104 and to secure the upper roof 104 to the collar 112 . The slots 172 are through going openings in the reinforcement plates 172 and the rafters 126 . The slots are generally “L” shaped and in this embodiment are approximately ⅝″ slots 26″ long by 1½″ wide as shown in FIG. 2.
[0051] The pins 166 pass through the slots 174 and the brackets 164 so as to secure the rafters 126 and thus the slidable roof section 110 to the collar 112 during erection of the upper roof 104 so as to restrict translation of the slidable roof section 110 along the y 122 and z 124 axes and allow a limited degree of translation along the x axis 120 and also so as to restrict rotation of the slidable roof section 110 along the x 120 and z 124 axes yet allow rotation about the y axis 122 .
[0052] The upper roof 104 also comprises a lifting attachment 176 as shown in FIGS. 1, 4, 9 , and 10 . The lifting attachment 176 is attached to the underneath of the end piece 132 adjacent the first end 134 of the pivotable roof section 106 . The lifting attachment 176 removable attaches to an end of a lift 180 . In this embodiment, the lifting attachment 176 defines a socket and the end of the lift 180 defines a corresponding ball. The lift 180 is a hydraulically extensible jack of a type well known in the art. The lift 180 is positioned underneath the lifting attachment 176 extending vertically along the z axis 124 and further positioned such that the end of the lift 180 mates with the lifting attachment 176 . The lift 180 is then manipulated such that the lift 180 extends. Extension of the lift 180 urges the lifting attachment 176 and thus the first end 134 of the pivotable roof section 106 upwards. As the second end 136 of the pivotable roof section 106 is restrained as previously described, the pivotable roof section 106 pivots upwards such that the first end 134 is elevated relative to the second end 136 and the collar 112 .
[0053] The first ends 134 of the pivotable roof section 106 and the slidable roof section 110 are pivotably connected as previously described. Thus, as the first end 134 of the pivotable roof section 106 is elevated by the lift 180 , the first end 134 of the slidable roof section 110 is correspondingly elevated. As the pivotable roof section 106 and the slidable roof section 110 are two rigid bodies pivotably connected, as the line of connection is elevated relative to the ends, the upper roof 104 triangulates as the lift 180 elevates the lifting attachment 176 . Since the second end 136 of the pivotable roof section 106 is restricted from translation along the x axis 120 , as the first ends 134 of the pivotable roof section 106 and slidable roof section 110 are elevated by the lift 180 , the second end 136 of the slidable roof section 110 moves inwards along the x axis 120 as the pins 166 move within the slots 174 .
[0054] As the first ends 134 of the pivotable 106 and slidable 110 roof sections move upwards, the pins 166 move within the slots 174 of the slidable roof section 110 until the slidable roof section 110 drops into the end of the slots 174 as shown in FIG. 3. The pins 166 are then fastened so as to secure the pivotable 106 and slidable 110 roof sections from further movement in a known manner. Securing fasteners 182 are placed through the first ends 134 of the pivotable 106 and the slidable 110 roof sections to further interconnect the pivotable 106 and the slidable 110 roof sections as shown in FIG. 4. The fasteners 182 of this embodiment are ⅝″ hex bolts and corresponding nuts of known types. The fasteners 182 are secured to the pivotable 106 and the slidable 110 roof sections in a well known manner. The lift 180 is then retracted and removed and the upper roof 104 is thus placed and secured in the pitched configuration 114 .
[0055] The modular school building system 100 also comprises a plurality of anchor assemblies 184 as shown in FIG. 6. The anchor assemblies 184 interconnect the frame modules 102 to the building's foundation footings 192 to restrict uplift and horizontal displacement forces acting on the building due to seismic events or high wind conditions. The anchor assemblies 184 of this embodiment comprise an angle 186 and two anchor bolts 190 . The angle 186 is an “L” shaped piece of ½″ steel plate approximately 5″×3½2″×8″. The anchor bolts 190 are ½″ “L” shaped threaded rods approximately 8″ long. The foundation footing 192 in this embodiment is a concrete slab of a type well known in the art.
[0056] In this embodiment, the anchor bolts 190 are connected to the angle 186 by welding in a known manner so as to form the anchor assemblies 184 . The anchor assemblies 184 are set in the foundation footing 192 so as to rest flush with the surface of the foundation footing 192 prior to the formation of the foundation footing 192 in the manner illustrated in FIG. 6. The rigid and massive structure of the foundation footing 192 enclosing the anchor assemblies 184 provides high resistance of the anchor assemblies 184 to tensile and compression forces acting on the anchor assemblies 184 along the x 120 , y 122 , and z 124 axes.
[0057] The anchor assemblies 184 are then rigidly connected to the vertical supports 144 , the outer wall sills 146 , end sills 150 , and the anchor stubs 152 . In this embodiment, the connection comprises welding in a known manner. Thus the vertical supports 144 , the outer wall sills 146 , end sills 150 , and the anchor stubs 152 are rigidly connected to the anchor assemblies 184 and thus to the foundation footing 192 . Thus vertical and horizontal forces acting on the frame module 102 are transferred through the vertical supports 144 , the outer wall sills 146 , end sills 150 , and the anchor stubs 152 to the anchor assemblies 184 and thus to the foundation footing 192 . Thus vertical and horizontal forces acting on the building are resisted by the modular school building system 100 and damage to the building is thereby inhibited. The interconnection of the frame modules 102 to the anchor assemblies 184 provides a steel moment resisting frame along both the x 120 and the y 122 axes.
[0058] After the frame modules 102 are connected to the anchor assemblies 184 in the manner previously described, a floor slab 194 , rigid filler 196 , and resilient filler 200 are emplaced on and around the foundation footings 192 and the frame modules 102 as shown in FIG. 7. In this embodiment, the floor slab 194 is a planar layer of concrete approximately 4″ thick poured to encase the anchor stubs 152 , end sills 150 , and outer wall sills 146 so that the surface of the floor slab 194 is flush with the upper surfaces of the anchor stubs 152 , end sills 150 , and outer wall sills 146 in a well known manner. The rigid filler 196 comprises grout and the resilient filler 200 comprises bituminous expansion material. The rigid filler 196 and resilient filler 200 fill the cavity defined between the edge of the floor slabs 194 and the anchor stubs 152 , end sills 150 , and outer wall sills 146 . The rigid filler 196 and resilient filler 200 provide additional strength to the modular school building system 100 by providing additional physical support between the foundation footing 192 , the floor slab 194 , and the frame module 102 . The resilient filler 200 provides a restricted freedom of movement between the floor slab 194 and the frame module 102 to accommodate differential thermal expansion between the floor slab 194 and the frame module 102 during temperature changes.
[0059] The modular school building system 100 also comprises interior wall assemblies 202 as shown in FIG. 8. The interior wall assemblies 202 are generally rectangular and in this embodiment are approximately 9′×4′×6″. The interior wall assemblies 202 are non-load-bearing structures that extend from the floor slab 194 to the collar 112 and partition the interior of the frame modules 102 . The interior wall assemblies 202 comprise pre-assembled wall panels 204 . The wall panels 204 are generally rectangular and in this embodiment are approximately 9′×4′×6″. The wall panels 204 comprise a steel frame and insulation constructed in a well known manner.
[0060] The interior wall assemblies 202 also comprise interior finishings 212 . The interior finishings 212 are generally rectangular and, in this embodiment, are approximately 9′×4′×½″. The interior finishings 212 of this embodiment comprise sheet rock panels of a type well known in the art. The interior finishings 212 are placed adjacent to the wall panels 204 and aligned with the wall panels 204 so as to be parallel. The interior finishings 212 are attached to both sides of each wall panel 204 with fasteners 220 so as to be adjacent and aligned with the major plane of the wall panels 204 in a well known manner. In this embodiment, the fasteners 220 comprise Number 10 sheet metal screws. The interior finishings 212 provide additional structural strength and insulation to the interior wall assemblies 202 and further provide an advantageous surface for the application of known coverings such as paint, wood paneling, and wall paper.
[0061] The interior wall assemblies 202 also comprise a header channel 206 and footer channel 210 . The header 206 and footer 210 channels of this embodiment are made of c-channel 20 gauge steel and are approximately 4′×4″×1½″. The header 206 and footer 210 channels define interior cavities 224 as shown in FIG. 8. The header 206 and footer 210 channels are positioned such that a top edge 226 of the wall panel 204 occupies the interior cavity 224 of the header channel 206 and the bottom edge 230 of the wall panel 204 occupies the interior cavity 224 of the footer channel 210 . Thus the header 206 and footer 210 channels are adjacent the top 226 and bottom 230 edges respectively of the wall panel 204 . The header 206 and footer 210 channels are attached to the wall panel 204 in a well known manner with fasteners 220 , which in this embodiment, comprise Number 10 sheet metal screws placed approximately 16″ on center.
[0062] The interior wall assemblies 202 also comprise a ceiling track 214 . The ceiling track 214 is an elongate member made of 16 gauge steel c-channel approximately 4″×2½″ in cross section. The length of the ceiling track 214 is dependent on the placement of the corresponding interior wall assembly 202 and the overall dimensions of the building employing the modular school building system 100 , however would be obvious to one skilled in the art. The ceiling track 214 also defines an interior cavity 224 . The interior cavity 224 and thus the ceiling track 214 is sized such that the top edge 226 of the wall panel 204 with the header channel 206 connected in the manner previously described, fits snuggly within the interior cavity 224 of the ceiling rack 214 . The ceiling track 214 is positioned adjacent the collar 112 preferably extending along the x 120 or the y 122 axes such that the interior cavity 224 faces downwards along the z axis 124 . The ceiling track 214 is attached to the collar 112 with a plurality of fasteners 220 in a well known manner. In this embodiment, the fasteners 220 are Number 10 sheet metal screws placed no more than 24″ on center.
[0063] The interior wall assemblies also 202 comprise footing braces 216 . The footing braces 216 are elongate members made of 16 gauge 90° steel angle approximately 1½″×1½″. The length of the footing braces 216 is preferably substantially equal to the length of a corresponding ceiling track 214 selected in the manner indicated above. A first footing brace 216 is placed adjacent the floor slab 194 so as to be parallel with and aligned to the corresponding ceiling track 214. The first footing brace 216 is attached to the floor slab 194 with fasteners 222 in a well known manner. In this embodiment, the fasteners 222 are 0.145″ diameter concrete nail placed no more than 24″ on center.
[0064] The top edge 226 of the wall panel 204 with the attached header channel 206 is placed into the interior cavity 224 of the ceiling track 214 such that the top edge 226 of the wall panel 204 is approximately ½″ away from the collar 112 as measured along the z axis 124 . The wall panel 204 is then positioned so as to be vertically aligned along the z axis 124 such that the bottom edge 230 of the wall panel 204 with the attached footer channel 210 is adjacent the first footing brace 216 . The second footing brace 216 is then positioned adjacent to and aligned with the bottom edge 230 of the wall panel 204 so as to be parallel with the first footing brace 216 and so as to fit tightly against the floor slab 194 to thereby stabilize the wall panel 204 . The bottom edge 230 of the wall panel 204 is then attached to the first and second footing braces 216 with a plurality of fasteners 220 in a known manner. In this embodiment, the fasteners 220 are Number 10 sheet metal screws placed no more than 16″ on center.
[0065] Thus the interior wall assembly 202 is secured at the top edge 226 to the ceiling track 214 and thus the collar 112 and the bottom edge 230 is secured to the footing braces 216 and thus the floor slab 194 . The approximately ½″ spacing between the wall panel 204 and the collar 112 provides clearance for a limited deflection of the collar 112 without loading the interior wall assembly 202 .
[0066] [0066]FIG. 9 illustrates three frame modules 102 interconnected together and anchored to the floor slab 194 . In this embodiment, the anchor assemblies 184 are placed within the foundation footings 192 in the manner previously described. Then the frame modules 102 are placed on the foundation footings 192 such that the anchor stubs 152 are all aligned with a corresponding anchor assembly 184 . The anchor stubs 152 , end sills 150 , and outer wall sill 146 are then connected to the anchor assemblies 184 in the manner previously described. The three frame modules 102 are then interconnected to each other along the vertical supports 144 and adjacent ends of the end sills 150 and the anchor stubs 152 . In this embodiment, interconnecting the vertical supports 144 and adjacent ends of the end sills 150 and the anchor stubs 152 comprises welding, however, it should be appreciated that interconnecting can also be adapted by one skilled in the art to include fasteners, adhesives, clinches, or other methods of joining materials. The frame modules 102 are further connected along adjacent perimeter beams 142 with a plurality of fasteners 143 . The fasteners 143 of this embodiment are ⅝″ bolts and corresponding nuts placed and secured to the perimeter beams 142 approximately 8″ on center in a known manner.
[0067] The lift 180 is then positioned to mate with the lifting attachments 176 of the frame modules 102 and manipulated so as to raise the frame modules 102 to the pitched configuration 114 in the manner previously described. Adjacent rafters 126 of the frame modules 102 are interconnected, in this embodiment, with a plurality of fasteners 220 placed approximately 8″ on center along the major axis of the rafters 126 so as to form a contiguous upper roof 104 in the pitched configuration 114 . The lift 180 is then distanced from the frame modules 0.102 and the interior wall assemblies 202 are then installed in the manner previously described. Then appropriate building materials such as plumbing, electrical and telephone wiring, ceiling panels, carpeting, and roofing is applied to the modular school building system 100 to complete a school building in a known manner. It should be appreciated that the exact order of assembly of the modular school building system 100 and manner of finishing materials employed can be readily modified by one skilled in the art to meet the needs of particular applications without detracting from the spirit of this invention.
[0068] [0068]FIG. 10 illustrates a frame module 102 of the modular school building system 100 in the flat configuration 116 . As can be appreciated from comparing the illustrations of FIG. 10 and FIG. 1, the overall height of the frame module 102 in the flat configuration 116 is substantially less than its height in the pitched configuration 114 . In this embodiment, the height of the frame module 102 in the flat configuration 116 is approximately 11½′. The frame module 102 is also approximately 12′ wide by 40′ long. As will be appreciated by one skilled in the art, the frame module 102 of approximately 1½′×12′×40′ in the flat configuration 116 can be readily loaded onto a standard low flat-bed trailer and transported over the road without interference with standard highway overpasses and bridges. Thus, the modular school building system 100 can be readily transported in a substantially preassembled state from the point of manufacture to the intended building site. Thus, the modular school building system 100 provides increased economy and speed of construction to the building trades.
[0069] Although the preferred embodiments of the present invention have shown, described and pointed out the fundamental novel features of the invention as applied to those embodiments, it will be understood that various omissions, substitutions and changes in the form of the detail of the device illustrated may be made by those skilled in the art without departing from the spirit of the present invention. Consequently, the scope of the invention should not be limited to the foregoing description but is to be defined by the appended claims.
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A substantially preassembled modular frame system for erecting permanent school buildings. The system design, materials, and construction have been pre-approved by state inspectors. The system provides a roof that is extensible from a low position that is configured to permit the system to be transported on highways and fit under common overpasses and bridges to a pitched position that provides a sloped roof profile to improve insulation factors of completed buildings and better shed rain, snow, and debris. The system includes anchor assemblies that are rigidly connected to the frame to inhibit uplift forces acting on the building from distorting or dislodging the building from the foundation. The system also includes preassembled wall panels and a convenient mechanism for emplacing and securing the wall panels within the modular frames.
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BACKGROUND OF THE INVENTION
The present invention relates to a device and a method for the separation into its individual components of a sample which is injected into a stream of carrier gas in the capillary conduit of a gas chromatography analysis apparatus. "Sample" here means a certain quantity of a solution of one or more components dissolved in a solvent.
FIELD OF THE INVENTION
The invention has applications in gas chromatography analysis in general and in the gas chromatography analysis of high volume samples in particular.
It is known that, gas chromatography analysis involves a complex preparation method for the sample which includes such steps as extraction, concentration and purification. These operations are not only time consuming but also introduce a series of errors into the result of the analysis itself.
Gas chromatographic analysis is usually carried out on an apparatus fitted with a capillary conduit consisting generally of a pre-column "retention gap", a capillary analytical column lodged in an oven, and an injector upstream of the pre-column. There is a supply line connected to the injector for a carrier gas which carries the sample through the capillary conduit. Generally, a means of regulating the oven temperature and a means of regulating the pressure of the carrier gas fed into the injector are provided.
In particular, e.g. for an apparatus fitted with "on-column" type injectors, there is a "T" link between the pre-column and the capillary analytical column that connects the capillary conduits to a valve, known as "Solvent Vapour Exit" (SVE), by a length of capillary tubing. The SVE permits the vapour phase of the solvent to exhaust from the pre-column of the apparatus.
The injection of high volume samples simplifies the preparation method of the sample by reducing or even eliminating the sample-concentration step but causes more complications in the step of separating the solvent from the sample.
In fact is well known, the step that immediately precedes the gas chromatographic analysis with the type of apparatus described above involves the evaporation of a certain quantity of solvent from the solution that constitutes the initially injected sample. Most of the solvent (which is always the most volatile component of the sample) is removed in the vapour phase through the SVE valve. The latter is closed at a certain point in such a way as to transfer the sample compounds and the solvent residue from the pre-column to the capillary analytical column. In other words, what arrives on the capillary analytical column is the remnants of the "desolvation" i.e. what remains after removal of the excess solvent.
The main problem in the known art, especially where the sample volume is high, is to determine the exact moment to close the valve in such a way to give reliable, repeatable analyses and to transfer a quantity of sample to the analytical column compatible with the column itself.
In practice, if the valve is closed too soon, the residual volume arriving on the capillary analytical column will still contain a high percentage of solvent and will overload the analytical column. This results in what is known as the "flooding effect" where the output signal is not sufficiently defined and the efficiency of separation process is prejudiced. By "signal" here is meant the plot generated by detectors of known type downstream of the gas chromatography apparatus. The plot generally consists of a series of peaks, each representing the identification of particular compound contained in the sample.
On the other hand, if the valve is closed too late, some of the components of the sample are eliminated, thus prejudicing the reliability of output signal.
According to the currently known methods, the instant of closing of the valve is determined empirically. In practice, the method for determining the optimal method defined by a series of parameters which correspond to the analysis conditions (i.e. oven temperature, carrier gas pressure, etc.), involves the repetition of single analysis where the solvent evaporation valve opening time is varied in relation to some of the aforementioned parameters. The repetition continues until an output signal is obtained that identifies all the compounds of interest in the sample with the required accuracy.
It is obvious how labourious and expensive such a method of determining optimum analysis conditions is in terms of both resources and time.
The use of gas chromatography analysis apparatus with the method as known at present does not lend itself readily to repeated analysis involving variation of even one of the experimental conditions e.g. the oven temperature in which the analytical capillary column is housed, the initial volume of the sample, the carrier gas pressure or any of the other conditions that influence the previously established opening time of the valve.
OBJECTS OF THE INVENTION
The aim of the present invention is to overcome the drawbacks of the present art.
An object within the scope of this aim is the provision of a device and a method which will produce correct gas chromatographic analyses in a short time and will give well defined signal at the output of the detector.
A further object of the present invention is the provision of a device and a method which will easily reproduce the same experimental conditions for the analysis of different samples, or to repeat the analysis on the same sample while varying one or more of the experimental conditions of a previously determined optimum analytical method.
Another object of the present invention is the provision of a device and a method which will facilitate the analysis of samples having particularly large volumes.
SUMMARY OF THE INVENTION
These objects are achieved by the present invention which relates to a device for the separation into its individual components of a sample which is injected into a stream of carrier gas in the capillary conduit of a gas chromatography analysis apparatus, where the sample consists of a solution of one or more components dissolved in a solvent. The device is characterized by comprising:
means for memorizing a plurality of reference values R evap corresponding to the evaporation rates of solvents, combined with the carrier gases used, corresponding to a plurality of discrete values between respective pre-set intervals, the said discrete values being representative of specific pressure conditions of the carrier gas in the capillary conduit, of specific temperatures to which said capillary column is subjected to, of pre-set initial volumes of the sample injected in said capillary column and of pre-set injection rates of the sample;
means for calculating and memorizing the effective R evap value for evaporation rate of solvent corresponding to actual carrier gas pressures in the capillary conduit, actual temperatures to which the capillary conduits is subjected, actual sample initial volumes and actual injection rate; and
means for generating one or more control signals for the gas chromatography analysis apparatus to determine the volumetric fraction of the sample transferred through the capillary conduit in relation to its characteristics and its geometrical dimensions.
The means of calculating and memorizing the r evap and R evap values for the evaporation rates of solvents preferably comprise a processor with a means of function selection and/or data input as well as a means of displaying information related to the said processor.
In fact, the device thus conceived allows the parameters of each phase of solvent separation of the separation to be input and calculated. The processor follows a program which guides the operator through a series of steps to select for example, the carrier gas and/or solvent used, the geometric parameters of the capillary column together with other functions and operations which will be described below.
The invention provides a simple and effective way of controlling the injection of high-volume samples, thus limiting the time spent on preparing the sample for analysis.
It is further possible to memorize the information related to the particular set of conditions for an individual analysis, thus enabling the repetition of the analysis in the same conditions.
The means for generating the control signals for the gas chromatographic analysis apparatus preferably comprise a control unit connected to the processor and the gas chromatographic analysis apparatus.
In this way an "open circuit" control system is set up which has the advantage of allowing the analysis to be done under conditions either controlled automatically by the processor and/or set up manually by the operator. In other words, the operator may select to set up the analysis conditions automatically on the basis of the specific parameters already known (e.g. corresponding to a process of analysis that has already given satisfactory results), but may also choose to change one or more parameters, within determined limits, according to the requirements of the analysis.
The invention also relates to a method for the separation into its individual components of a sample which is injected into a stream of carrier gas in the capillary conduit of a gas chromatography analysis apparatus, in which the sample consists of a solution of one or more components to be analized dissolved in a solvent. The method is characterized by comprising:
the preliminary calculation of a plurality of reference values R evap corresponding to the evaporation rates of solvents, combined with the carrier gas used, corresponding to a plurality of discrete values at respective pre-set intervals, the said discrete values being representative of specific pressure conditions of the carrier gas in the capillary conduit of specific temperatures to which said capillary conduit is subjected to, of pre-set initial volumes of the sample injected in said capillary conduit and pre-set injection rates of the sample;
the calculation of the effective R evap value for evaporation rate of solvent corresponding to actual carrier gas pressures in the capillary column, actual temperatures to which the capillary column is subjected to, actual sample initial volumes and actual injection rates;
the generation of one or more control signals for the gas chromatography analysis apparatus to determine the volumetric fraction of the sample transferred through the capillary conduit in relation to its characteristics and its geometrical dimensions.
In practice, it is particularly advantageous to establish beforehand the volumetric fraction of the sample that is to go onto the analytical capillary column. The relation which expresses the volumetric equilibrium for a sample injected onto a gas chromatography analysis apparatus is the following:
V.sub.inj =V.sub.evap +V.sub.ret (I)
where:
V inj is the total volume of the sample injected, i.e. the sum of the volume of the solvent and the volume of the compounds to be analyzed;
V evap is the fraction of the volume which is removed through the SVE valve, the said volume fraction being comprised of solvent alone, and
V ret is the fraction of the volume that is retained on the pre-column, the said volume fraction being comprised of compounds to be analyzed and the residual percentage of solvent. This is in practice the quantity of sample which will reach the analytical capillary column when the SVE valve is closed.
Since the volume injected V inj and the volume which goes onto the capillary column V ret are known, then the volume of solvent vented through the SVE valve V evap can be calculated from equation (I).
When V evap is known, the valve open time t is given by the relation
t=V.sub.evap /r.sub.evap (II)
in which r evap is the evaporation rate of the solvent under operating conditions.
However, calculating the evaporation rate r evap of the solvent is not simple, since the value is influenced by many factors which depend on, for example, the physical characteristics of the liquid and vapour phases of the solvent, the physical characteristics of the carrier gas, the conditions in which the solvent is separated i.e. the initial temperature of the injected sample, the volume initially injected, the injection rate, the carrier gas pressure and the oven temperature. Further factors influencing the evaporation rate is the nature of the inner surface of the pre-column and its physical parameters i.e. length and internal diameter.
In practice, by using a pre-column with fixed physical parameters, the following relationship can be established for the r evap :
r.sub.evap =f(P,T,V.sub.inj,U.sub.inj,Solv) (III)
where the variables P, T, V inj , are respectively the carrier gas pressure in the column, the oven temperature, and the volume injected, i.e. the analysis initial conditions which are maintained constant during injection and removal of the solvent. The variable U inj is the sample injection rate, while Solv represents the set of those variables related to the physical characteristics of the solvent e.g. density, viscosity, entropy of the liquid and vapour states, the specific heat in the liquid state etc.
To avoid having to calculate an extremely complex equation, which would take a lot of time even on powerful computers, it is preferred to determine a series of only evaporation rate reference values R evap empirically for pre-set values of the variables P, T, V inj , U inj .
The experimental determination of a series of evaporation rate reference values R evap for pre-set values of the four variables P, T, V inj , U inj also avoids the difficulty of defining the numerous Solv variables that define the solvent, together with those which characterize the gaseous mixture composed of solvent in the vapour phase and the carrier gas.
In practice, for each combination of one of a number of solvents with one of a number of carrier gases, a reference value R evap (i,j,k,s) is determined experimentally for the evaporation rate of the solvent for a plurality of values of only the variables P i ,T j ,V k and U s within pre-set limits. The values R evap (i,j,k,s) for a determined combination of solvent/carrier gas can be collected into a single matrix and easily memorized in a computer.
According to a preferred aspect of the method proposed by the present invention, the effective evaporation rate r evap is calculated by interpolation of the geometrically nearest R evap reference values in the environment determined by the actual conditions of carrier gas pressure in the capillary conduit, actual temperature, to which is subject the capillary conduit, the actual initial sample injected volume and the actual sample injection rate.
This allows considerable simplification of the calculation of the effective evaporation rate of the solvent for any set of values of the variables P, T, V inj and U inj imposed in the respective ranges of variability.
The method also allows conditions for the carrying out of the analysis to be optimized for all its phases.
For example, the method provides for the calculation of the temperature and pressure conditions which must be maintained during sample injection and solvent removal to ensure the maximum volume of injected sample in the pre-column, and the distinct temperature and pressure conditions which must be maintained after the SVE valve is closed to ensure optimum flow in the analytical capillary column.
As a further optimization possibility, the method provides for the calculation of the carrier pressure and temperature that must be maintained during the sample injection and solvent removal phase in order to ensure a pre-set flow rate of solvent vapour through the SVE valve, and the distinct temperature and pressure conditions which must be maintained after the SVE valve is closed to ensure optimum flow in the analytical capillary column.
Provision is also made for the calculation and/or manual setting of carrier gas pressure and temperature that must be maintained constant during the entire analysis i.e. not only for the sample injection and solvent removal phase but also for the transfer of the compounds of the sample residue from the pre-column to the capillary column after the SVE valve is closed.
These and other advantages will be more evident from the description which follows, which is illustrative and not limiting, where reference is made to the attached sketches in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a scheme of the device according to the invention;
FIG. 2 shows the operations carried out or made available by the computer according to an embodiment of the method of the present invention;
FIG. 3 is a diagram of the domain of selectable gas pressures and oven temperatures on the Cartesian plane (T;P).
FIG. 4 is a diagram of the reference values R evap on the domain shown in FIG. 3 of the Cartesian plane (T;P).
FIGS. 5 to 8 show diagrams of some examples of Cartesian planes (T;P) similar to those displayed on the computer monitor during the inserting of gas pressures and oven temperatures values according to the method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The apparatus 1 comprises substantially an oven 2, an injector 3 (preferably of the "on-column" type) to inject the sample to be analyzed, a valve 4 to allow the evacuation of the solvent in the vapour phase (SVE valve), a detector 5 connected to the outlet of the capillary analytical column 6, lodged in the oven 2. To the injector 3 is connected a supply line 7 for the carrier gas; on the said supply line a valve 8 is arranged, said valve being operated electronically to regulate the flow rate and the pressure of the carrier gas to the apparatus 1.
Inside the oven 2, as well as the capillary column 6, there is a pre-column 9 connected downstream of the injector 3 and upstream of the capillary analytical column 6. Between the pre-column tube 9 and the analytical capillary column 6 there is a "T" junction 10 from which a tube 11 departs that connects the capillary ducts 6 and 9 to the valve 4. Inside the oven 2 there are means 12 of regulation of the temperature in the same oven.
The device according to the invention provides for a control unit 13 to generate the necessary control signals for the valve 8 on the carrier gas supply line, the means 12 of regulating the temperature, the injector 3 and the evacuation valve 4 of the solvent.
The control unit 13 is in turn connected to a computer 14 from which it receives the inserted and/or calculated data for each phase of analysis. The computer 14 may be of any commonly known type, comprising at least a monitor 15, a hard-disk memory unit, a RAM memory, a keyboard 16 and a mouse 17 to select functions and/or insert data.
The hard-disk of the computer 14 stores a plurality of reference values R evap corresponding to the evaporation rates of the solvent in relation to a corresponding plurality of discrete values of the variables P i , T j , V k and U s within respective pre-set intervals. The values of R evap (i,j,k,s) for a particular combination of carrier gas and solvent can be collected into a single matrix and memorized on the computer 14 as such.
In other words, the reference values of the evaporation rates of the solvent are calculated only in terms of pre-set conditions i.e. for discrete representative values of the carrier gas pressure in the supply line 7, of the temperature inside the oven 2, of the initial volume of injected sample, and of the injection rate.
The keyboard 16 and the mouse 17 allow the insertion or the selection of the data which characterize the actual analysis in all its phases.
Also memorized in the computer are the data relating to the geometrical parameters of the capillary columns 6 and 9, e.g. length and internal diameter of the capillary column 6, data related to the volume of the injected sample, and data relating to the temperature inside the oven 2 and the pressure conditions of the carrier gas. All data are arranged in configurations which allows it to be moved easily between the hard-disk and the RAM.
The computer 14 allows the effective value of the evaporation rate r evap of the solvent in use to be calculated in relation to data stored in the memory and/or inserted by the operator, and thus to calculate the parameters which characterize each phase of the gas chromatography analysis.
FIG. 2 shows a sequence comprising some of the steps the operator must go through on the computer 14 to set up an analysis correctly. In the case shown, it is presumed that some parameters are pre-inserted e.g. those related to the kind of carrier gas to be used and the type of retention gap 9 used in the gas chromatography apparatus. Furthermore, the reference values R evap are presumed to have been already calculated and memorized on the computer 14.
According to a preferential embodiement of the invention, a program is used which allows interaction between the operator and the computer 14 by means of a graphic interface. The selection of the data to be input in the steps of FIG. 2 referred to above can be done either by the keyboard 16 or the mouse 17. It is important to state that the program run by the computer 14 has other functions which are not shown in FIG. 2; e.g. the memorization of a particular configuration on the hard disk; the retrieval of a particular configuration from the hard disk and recally it to the RAM; the sending of information related to a particular configuration to the control unit 13.
The information contained in blocks 201 and 202 is requested at step 20 of FIG. 2.
Block 201 indicates the selection of the solvent used in the preparation of the sample to be analyzed. The selection of the solvent gives the computer 14 the information it needs to identify the matrix of reference values R evap to be used to calculate the actual values r evap related to the evaporation rate of the solvent.
Block 202 indicates the inputting of the geometrical characteristics of the analytical capillary column, in particular the length and internal diameter, i.e. the data which influence the flow in the analytical column 6 after the solvent elimination phase.
The order in which operations 201 and 202 are carried out at stage 20 is unimportant.
The information contained in blocks 211 and 212 is requested at step 21 of FIG. 2. Blocks 211 and 212 indicate respectively the carrier gas pressure and the oven temperature at which the capillary conduit sections 6 and 9 in the oven 2 are maintained during the desolvation. Once it has received the values of pressure and temperature, the computer 14 proceeds to calculate the series of parameters particularly important indicated by the block 213. In particularly, it is made the calculation of the actual evaporation rate r evap of the solvent. Once r evap is known, the maximum injection volume V max , the volume of pre-column 9 with the valve 4 open and the volume of the conduit comprising the analytical column 6 and the pre-column 9 with the valve 4 closed, can all be determined.
At stage 22 information (block 221) relating to injected sample volume is requested, while at stage 23 information (block 231) relating to residual volume which remains in the pre-column 9 after the valve 4 has been closed and which will transfer to the analytical column 6 after the valve 4 has been closed, is requested.
At this point, the computer 14 can complete the calculation of the other remaining parameters needed to complete the information necessary to the carrying out of the analysis. Block 232 contains the information relating to the sample injection rate and the time the valve 4 remains open after the end of the sample injection phase.
FIG. 3 shows a Cartesian plane (T,P) containing the domain 215 from which the values of P and T can be selected at stage 21 of FIG. 2. FIG. 4 shows the same domain 215 of FIG. 3 in which the reference values R evap calculated corresponding to the discrete value pairs (P i ,T j ) are indicated by (x).
The point A(T A ,P A ) is any point within the domain 215 for which there is no a priori reference value R evap ; i.e. a pair of values T A and P A which represent the conditions of temperature and pressure imposed by the operator in stage 21 of FIG. 2.
According to the method of the present invention, the calculation of the actual value of the evaporation rate of the solvent r evap is by interpolation to the geometrically nearest reference value R evap to the point A i.e. the R evap for which the expression
(P.sub.A -P.sub.i).sup.2 +(T.sub.A -T.sub.j).sup.2
is minimum.
For example, the geometrically nearest reference value R evap to point A in FIG. 4 is that corresponding to T=50° C. and P=125 kPa.
FIG. 5 shows an example of a Cartesian plane (T,P) which is displayed on the monitor 15 of the computer 14 during selection of the temperature and pressure by the operator, during the initial selection of such values. The hatched area 215 in FIG. 5 shows the domain 215 already indicated in FIGS. 3 and 4, while the shaded area 216 shows the domain of the values of temperature and pressure which would give optimum flow conditions in the capillary column 6 after the valve 4 is closed.
In practice, the point D (T D , P D ) could be in any position inside the area 215 but is not limited in any way to any position in area 216. So, if point D is inside the intersection of the areas 215 and 216 (as is shown in FIG. 5), then conditions can be chosen which are valid both for the sample injection and solvent removal phase, and for the transfer of the residual sample fraction from the pre-column 9 to the analytical capillary column 6. If point D is inside the area 215 but not inside area 216, then the flow rate through the column 6 will not be optimum for the analytical capillary column size after the valve 4 is closed.
According to an advantageous aspect of the present invention, once a desired temperature has been selected, it is possible to select an initial pressure suitable to the sample injection and solvent removal phase, and a second pressure suitable for the sample transfer to the analytical column phase.
As is shown in FIG. 6, an initial point B (T B ,P B ) can be selected which defines the temperature and pressure conditions during injection of the sample and removal of the solvent, and a second point C (T C , P C ) which defines the temperature and pressure conditions after the valve 4 is closed. Point B may be anywhere within the area 215 and point C may be anywhere within the area 216.
Both points B and C define preferably identical temperatures of the oven 2 that is (T B =T C ) while the carrier gas pressures may be different in successive phases. In this way it is possible to optimize each phase of the analysis according to different criteria.
For example, an initial criterium for optimization might be maximum volume injectable in the pre-column 9. It is known that--all other things (e.g. temperature and pre-column type) being equal--the volume of sample which can be injected on the pre-column increases with increasing carrier gas pressure. However, a high carrier gas pressure may not be ideal in the capillary analytical column after the SVE is closed. So, it is particularly advantageous to be able to set one pressure P B to give large volume sample injection and then a second pressure P C which gives optimum analytical column flow performance. The program run by the computer 14 facilitates the selection of such optimization which may be selected at stage 21 of FIG. 2. In particular, a diagram similar to that of FIG. 5 is shown on the monitor 15 when the operator must select temperature and pressure, on which the point D represents the predefined values of temperature T D and pressure P D , e.g. the default values calculated by the program and/or memorized by the computer 14. The operator may keep those values or adjust the temperature and/or pressure while keeping the point D within the area 215.
By selecting the optimization option (e.g. based on the maximum volume of sample that could be injected), the monitor displays the diagram according to FIG. 6 where for the predefined temperature T D (with T D =T B =T C ) a pressure value B is chosen, calculated automatically by the program, which gives the maximum volume of sample that may be injected, while the pressure value C is chosen, again calculated automatically by the program, which gives the optimum flow conditions in the analytical capillary column. In this case the pressure PB is always greater than the pressure PC while the temperature TB and TC are kept constant at the same value TD which was calculated or set before the optimization.
Even in the case shown in FIG. 6, the operator can adjust the position of point B inside the area 215 and the position of point C within the area 216. It must be remembered that any adjustment of point B and/or point C will alter the optimum conditions that were previously calculated by the program for the temperature TD previously calculated or set.
A further criterion of optimization of the method according to the present invention is the imposition of a pre-set solvent flow-rate through the valve 4. This option (which is particularly practical for operators in the field) allows the automatic calculation of conditions which give optimum flow rate in the analytical capillary column after the valve 4 is closed, while the solvent flow-rate through the said valve 4 in the prior phase is set by the operator. The practice is widespread of estimating approximately both the length of time the valve SVE is open and the quantity of solvent removed through it on the basis of the flow-rate through the same valve. In practice, starting from the temperature T D previously calculated or set (FIG. 5) and selecting this optimization option, it is requested the imputting of the corresponding value to the desired flow-rate through the SVE valve. After this setting has taken place, a diagram is shown on the monitor as in FIG. 6 with two points B and C. In this case, however, the point B corresponds to the temperature T B and pressure P B which give the required SVE valve flow-rate, while the point C corresponds to the temperature T C and pressure P C which give the optimum flow-rate conditions in the analytical capillary column. In this case, unlike that of the optimization for the maximum injectable sample volume, the point B may be below point C. The possibility of establishing different conditions of pressure P B and P C during the analysis method, together with the optimization of such conditions according to any required criterion, may prove useful, if not indispensable, for working in particular circumstances. An example of such conditions is shown in FIGS. 7 and 8, in which the areas 215 and 216 have very limited overlapping portions.
The case in FIG. 7 is a real situation in which the solvent is n-hexane, the analytical capillary column is 13 meters long with an internal diameter of 0.1 mm. In the case in FIG. 8 the solvent is n-hexane, but the analytical capillary column is 5 meters long with an internal diameter of 0.32 mm.
The ability to select different conditions of temperature and/or pressure before and after the closing of the SVE valve allow the operator to select the most favourable conditions in which to carry out the analysis.
In any case, provision has been made to adjust other variables in order to correct the values that have been calculated automatically by the program. In particular, the program provides for the manual adjustment of certain parameters, among which are the sample injection flow-rate, the opening time of the valve 4, at least the carrier gas pressure during the sample injection and solvent removal phases, together with a temperature value different to that previously set or calculated by the program.
Any optimization previously carried out automatically by the program cannot be guaranteed after the variation of the aforementioned parameters by the operator. However, the ability to vary such values may be useful in the case of variation in some of the characteristics of solvents and/or carrier gases (e.g. purity) which are nominally similar but originate from different suppliers.
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A device and method are described for the gas chromatographic separation of a sample, aimed in particular at the analysis of large volume samples. Provision is made for the use of calculating and memorizing a plurality of reference values corresponding to the evaporation rates of solvents combined with a carrier gas for a corresponding plurality of discrete values representing the conditions of pressure, temperature, injected sample volume and sample injection rate. The effective solvent evaporation rate is then calculated in correspondence to the effective conditions in which the process is carried out to determine the volumetric fraction of the sample which is transferred through the capillary column in relation to its characteristics and geometrical dimensions.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of increasing efficiency of heating ventilation, air conditioning and refrigeration (HVAC&R) systems, wherein the compressor operates in a rapidly cycled unloaded mode when reduced system capacity is required. The present invention is directed to noticeably reducing the amount of compression work that is performed at these unloaded conditions when no or little amount of refrigerant is pumped through the compressor.
[0002] Refrigerant systems are utilized in many applications, such as air conditioners, heat pumps, refrigeration units, etc. As is known, a refrigerant is compressed in a compressor and then is circulated throughout the refrigerant system to condition a secondary fluid such as air supplied to a climate controlled indoor environment. Most of the time, the refrigerant systems operate unloaded, since full-load capacity is not demanded to compensate for various components of thermal load in the conditioned environment. Therefore, it is desirable to operate the refrigerant system as efficiently as is possible, and especially at part-load conditions.
[0003] Improving compressor efficiency is a goal of a design engineer as a compressor typically represents the highest source of power consumption in the refrigerant system. The compressors consume power by compressing the refrigerant from a suction pressure to a discharge pressure. The refrigerant system controls known in the art monitor and maintain temperature and humidity in the conditioned environment within specified tolerance bands, and adjust the capacity provided by the refrigerant system via compressor unloading when the thermal load in the conditioned space and demand for the refrigerant system capacity are reduced.
[0004] Various ways of reducing refrigerant system capacity by compressor unloading are known. In one known method, compression elements of a so-called scroll compressor are allowed to move in and out of engagement with each other at a fast periodic rate, typically being in the range of 5 to 30 seconds. When the two compression elements are engaged, the compressor provides a full-load capacity. When the two compression elements are out of engagement, they will no longer compress and circulate the refrigerant throughout the system.
[0005] Another way of unloading the compressor is to allow at least a portion of compressed refrigerant return to a suction line.
[0006] In either case, a noticeable amount of power is consumed to compress the residual refrigerant inside the compressor. As an example, in the system mentioned above, wherein the scroll compression elements are allowed to move away from each other, there is still some compression taking place on residual refrigerant, resulting into lost compression work and reduced refrigerant system efficiency.
[0007] The present invention is directed to reducing the amount of such wasted compression work and improving refrigerant system efficiency at part-load operation.
SUMMARY OF THE INVENTION
[0008] In the disclosed embodiment of this invention, a suction valve controlling the flow of suction refrigerant into the compressor is closed when the compressor is being operated in an unloaded mode. The valve is then opened (partially or fully) when the compressor is returned to the normal loaded mode. The valve moves from an open position to a closed position in a rapid fashion. The valve cycling rate is normally in the range of 5 to 30 seconds. The cycling rate is selected to optimize the valve reliability and allow the conditioned environment to maintain the desirable temperature level. If the valve is cycled to a often, the reliability of the valve can be compromised and if the valve is cycled infrequently the temperature within the conditioned environment may not be precisely controlled. Motor overheating can also occur, if the valve stays in the closed position for a substantial period of time, as the amount of refrigerant available to cool the motor is reduced. In this manner, the suction pressure reaching the compressor pump elements, when the compressor is in the unloaded mode, is reduced. Therefore, the amount of work required to operate the compressor in this unloaded condition is dramatically reduced. Thus, the present invention improves compressor and overall refrigerant system efficiency at part-load conditions, in comparison to the prior art.
[0009] In one embodiment, the compressor is a scroll compressor having two scroll compression elements. As is known, a refrigerant system may utilize a pulse width modulation control to periodically open and close a flow of a pressurized refrigerant to a chamber utilized to hold the two scroll compression members in contact with each other. When the two compression members are held in contact with each other, they can compress a refrigerant and deliver it downstream to other components within the refrigerant system. However, the pulse width modulation control periodically blocks flow of the pressurized refrigerant to this chamber. At that time, the scroll members can move out of contact with each other. When the scroll members are out of contact with each other, refrigerant is still compressed within the compression chambers, due to a finite gap between the unloaded scroll elements; however, the refrigerant will not be fully compressed. Further, in such a system, a flow control device positioned on the discharge line typically blocks flow of the refrigerant to a downstream condenser. Instead, a bleed line is opened to allow this partially compressed refrigerant to return to the suction line. By blocking off the suction flow to the compressor under these conditions, the present invention reduces the amount of work performed by the compressor, and thus increases the efficiency of the refrigerant system.
[0010] In another embodiment, the unloaded condition is simply allowing the discharge line to communicate back to the suction line. Again, by utilizing a control of a suction valve to block suction flow, the present invention reduces the power consumption required to partially compress the refrigerant.
[0011] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a schematic of a first embodiment of this invention.
[0013] FIG. 1B graphically shows the reduced power consumption of the present invention.
[0014] FIG. 2 shows another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] A refrigerant system 20 is illustrated in FIG. 1A having a compressor 24 . The compressor 24 is a scroll compressor having a non-orbiting scroll 26 inter-fitting with an orbiting scroll 24 . As known, the non-orbiting scroll 26 can move axially relative to the orbiting scroll 24 . A chamber 28 receives a flow of pressurized refrigerant from a source 30 . As known in the art, the pressurized source is normally at a higher pressure when the scrolls need to be engaged and at a lower pressure when the scroll elements need to be disengaged from each other. Often, the source of a higher pressure would be a discharge pressure and the source of a lower pressure would be a suction pressure. Also, as known in the art, the switch between a higher and lower pressure is accomplished by some type of a valving mechanism. The control 32 controls the flow of the pressurized refrigerant from the source 30 to a valve 36 . By controlling the flow of the pressurized refrigerant to the chamber 28 , the non-orbiting scroll 26 can come in contact with the orbiting scroll 24 , or allow it to move away from the orbiting scroll 24 . In one known embodiment, the control 32 communicates with an electronic control 38 , which causes the valve 36 to be repeatedly opened and closed utilizing pulse width modulation technique. When the valve 36 is closed, refrigerant flow to the chamber 28 is blocked. Under these conditions, the compressor 22 is effectively unloaded as the non-orbiting scroll 26 is allowed to move away from the orbiting scroll 24 .
[0016] Under normal operating conditions, refrigerant is compressed in the compressor 22 , passes through a condenser 40 , and an expansion device 42 , and is delivered to an evaporator 44 . Refrigerant passes back into the compressor 22 through a suction line 51 . However, when a reduction in capacity is desired, the control 38 operates the valve 36 along with the pulse width modulation control 32 to repeatedly and rapidly open and close the valve 36 utilizing a pulse width modulation technique. As this occurs, the non-orbiting scroll member 26 is allowed to repeatedly move away from and toward the orbiting scroll member 24 . The operation and control of this system is as known in the art. It is the control of the suction valve 46 that is inventive here.
[0017] In the present invention, operation under normal conditions is shown in FIG. 1B , where the compressor compresses the refrigerant between suction pressure P 1 and discharge pressure P 2 . Also, the operation under the prior art unloaded condition is between a suction pressure P 1 and a discharge P 3 .
[0018] The work shown in the area A is all lost work with this prior art system. All this work is lost as essentially no refrigerant is pumped through the compressor. The refrigerant is compressed from a relatively high suction pressure P 1 to a relatively high discharge pressure P 3 . This is all work lost.
[0019] With the present invention, by blocking the flow of suction refrigerant to the compressor through the line 51 by the valve 46 , the suction pressure P 1 ′ and discharge pressure P 3 ′ are both reduced. Blocking of the refrigerant flow in the line 51 by the valve 46 preferably occurs shortly before the scroll compressor elements are disengaged. In this case, the suction pressure downstream of the valve 46 is reduced, as the refrigerant will be pumped out from the compressor lower shell, dropping to a low pressure value P 1 ′. When the suction pressure P 1 ′ downstream of the valve 46 is reduced to the acceptable level, the scroll elements are disengaged. Under such circumstances, the lost compression work is equivalent to a much smaller area shown at B in FIG. 1B . Thus, by selectively blocking the flow of refrigerant through the suction valve 46 to the suction line 51 , when the compressor is operated in an unloaded condition, the amount of work required to be performed by the compressor 22 in the unloaded mode is dramatically reduced. When the compressor returns into the normal compression mode, the valve 46 is opened to permit the normal flow of refrigerant into the compressor 22 . Notably, the areas shown in FIG. 1B are an illustration and indicative of the compressor power consumption reduction, and not an exact empirical laboratory result. Even so, substantial energy savings are expected with the present invention.
[0020] FIG. 2 shows a refrigerant system 80 incorporating a compressor 82 , downstream shutoff valve 84 , an unloader line 86 and a shutoff valve 88 on the unloader line 86 . While the unloader line 86 may be a standard discharge line delivering compressed refrigerant downstream to a condenser as shown in FIG. 2 , the unloader line may also be connected to an intermediate compression point in the compression process. For purposes of the claims in this application, either location will be termed a “discharge line.” A condenser 90 , an expansion valve 92 and an evaporator 94 are positioned downstream of the compressor 80 . A suction shutoff valve 96 and an unloader shutoff valve 88 are both controlled by a control 98 . When reduced capacity is desired, the valve 84 is closed, the unloader valve 88 is opened, and the suction valve 96 is closed. Benefits, such as mentioned above with regard to the first embodiment, will then be achieved compared to normal unloaded operation. To prevent the refrigerant overpressurization in the discharge line, due to the closing of the valve 84 , the valve 88 is open at roughly the same time as the valve 84 is closed. The valve 84 allows the refrigerant to be by-passed upstream of valve 96 into the suction line. Again, the valve 96 is closed shortly before the valve 84 is closed and shortly before valve 88 is opened. As explained above, this is done to reduce the suction pressure downstream of the valve 96 prior to initiation of the unloaded operation. The compression work diagram for the unloaded operation would be similar to the one represented by the cross-hatched area “B” in FIG. 1B .
[0021] While two distinct ways of unloading a compressor are shown, it should be understood that any manner of unloading a compressor will benefit from the teachings of this invention. By closing off the inlet flow, the suction pressure experienced by the compressor will be reduced. In this manner, the amount of wasted compression work will be reduced as well.
[0022] It should be pointed out that many different compressor types could be used in this invention. For example, scroll, screw, rotary, or reciprocating compressors can be employed.
[0023] The refrigerant systems that utilize this invention can be used in many different applications, including, but not limited to, air conditioning systems, heat pump systems, marine container units, refrigeration truck-trailer units, and supermarket refrigeration systems.
[0024] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
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The present invention relates to a way of reducing the amount of energy required to partially compress a refrigerant in a compressor operating in a rapidly cycled unloaded mode. A valve on a suction line is closed when the compressor moves to the unloaded condition. In this manner, the amount of energy required to partially compress the refrigerant in the compressor, at the unloaded condition, is dramatically reduced.
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BACKGROUND OF THE INVENTION
Billions of articles of clothing and linen are folded each day, by hand. There have been numerous, previous attempts to create a practical machine to fold clothes. None of these attempts have resulted in widespread adoption.
SUMMARY OF THE INVENTION
This invention folds fabric articles automatically. Example articles include shirts, sweaters, pants, and towels, in a wide range of fabric types and sizes.
Prior art has attempted to reproduce the motions a human uses to fold clothing. These include grasping a portion of the article and using the flat of the hand to guide that portion to a desired position, creating a fold as an artifact, as it were, of guiding a movable portion compared to a fixed portion of the article to a new position. Such machines were typically considerable larger than the article to be folded. Compared to prior art, this invention requires less space and also reduces wrinkling.
In the scenario below, one embodiment of the invention creates folds by a different method. A rotating rod glides smoothly between layers of the article, with portions of the article both above and below the rod. A retractable tape is used to hold a portion of the article firm while the rod moves. A first fold is created at the edge of the tape. A second fold is created at the farthest motion line of the rotating rod. This process is typically performed on the left side of a shirt, for example, then the right side, then perpendicular on the body.
The article to be folded is generally placed on a horizontal support surface, also called a platform. The rotatable rods are above the platform and below the article. The tapes extend out over the article, then down on the article to hold a portion. The platform defines an X-Y plane, with a normal Z-axis from the platform upward through the article.
The rotating rod moves in either the X- or Y-axis orthogonal to the elongate rod axis. Vertical motion permits the rod to “pick up” a portion of the article, pass over the still tape, and thus create two folds. Note that either the platform may move up and down, or the rods, or the tapes, depending on embodiment. All motions described herein are relative, and thus are equivalently accomplished by moving the other elements of the invention and the fabric article.
The rod is conveniently associated with a tape, allowing us to refer to a rod-tape pair, even though the rod and tape may be moved independently. In a most general sense, the tape “holds” the article while the rod “folds” the article. Note that these components provide other functions in the invention, as well.
In one embodiment two rod-tape pairs are used, with their elongate axes parallel, in order to both speed the folding process and simply the mechanisms.
In another embodiment two rod-tape pairs are used at right angles, in order to create folds at right angles.
In another embodiment, a total for four rod-tape pairs are used, with two parallel sets, each of the two sets at right angles.
In other embodiments, either the platform of the invention rotates, thus rotating the article, or the rod-tape pairs rotate around the article. In either embodiment, folds at various angle, including 45°, right angles, and other angles are available.
Below is an exemplary scenario for an exemplary implementation. Broader capabilities and embodiments are explained later.
An operator places a long sleeved sweater, the fabric article, face up, roughly flat, upon a horizontal platform. The operator roughly aligns the sweater with a visible outline on the platform.
The embodiment has two horizontal, rotatable rods located above the platform, the elongate axes aligned with the sweater axis through the neck of the sweater. Each rod has a free end. We refer to these rods as the first and second rods. The embodiment also has a third and fourth, similar, horizontal, rotatable rods at right angles to the first and second rods. The sweater is placed over the rods.
Associated with each rod is a retractable, bi-stable, concave-convex tape. The tape retracts, winding into a tape container, or extends outward, horizontally, over the sweater, with the same axis as its associated rod. When extended, the tape is rigid. The tape is bi-stable in that its shape changes between the extended position and the retracted, rolled position. The concave surface facing the fabric article, such that the two edges of the concave surface first contact the article. We often refer to the rods and tapes as “rod-tape pairs” for convenience, but all motions of all rods and all tapes are independent of each other. Each rod and tape has an elongate axis.
Each rod and tape has a supported end and a free end. The mounts for a rod and tape in a rod-tape pair may be on the same side of the platform, or on opposite sides. Rods move horizontally in the X-Y plane, either along the X- or along the Y-axis. Tapes move up and down in the Z-axis.
We discuss key steps, in one embodiment, to perform one pair of folds, below. It is important to note that motions are relative. For example, the sweater moving up, or the tape moving down, are equivalent motions. We choose to describe motion to aid in readability without limiting implementations. The use of a “sweater” as a fabric article being folded is purely exemplary. The key components, for this description below, are as follows: (i) a sweater, which is on a (ii) platform; (iii) a tape; and (iv) a rod. For the key steps below, the sweater is resting on the platform; it does not move independently of the platform except for the portion of the sweater being manipulated. The steps of placing the sweater (manual or automated) on the platform and removing the sweater from the platform (manual or automated) are not included in these key folding steps. The motions described below are generally relative to the other four key components, as listed above. For example, “lowering the platform,” means that the sweater and the platform move downward relative to both the tape and rod, or relative to just the rod. The steps of initializing and self-testing of the invention are not included in these key folding steps.
For convenience, we organize the steps into four phases. The phases of steps are:
(I) grabbing the sweater;
(II) positioning the rod under the sweater;
(III) making the fold;
(IV) moving the rod back to first position;
(V) continuing with the next fold.
Some of the above phases are optional, depending on the article and the specific fold. For example, phase II may not be needed when the rod is already properly positioned. Phase V may not be needed if the fold just made is the final fold.
Key steps for one pair of folds are:
(I-A) the tape moves up over the sweater;
(I-B) the tape extends outward over the sweater;
(I-C) the tape lowers onto the sweater, so as to hold the sweater and define on the distal edge of the tape the fold line;
(II-A) the rod rotates in a first direction, this direction such that the upper surface of the rod rotates in the opposite direction as the next motion (IIC) of the rod while underneath a portion of the sweater;
(II-B) the rod is underneath the sweater distal to the tape; if it is not underneath the sweater, it is placed underneath the sweater;
(II-C) close to the platform, the rod moves under the sweater, while rotating, to a position as close to the distal edge of the tape as possible; this is the “pre-fold” position;
(III-A) the rotation of the rod reverses, such that the upper surface of the rod moves in the same direction as the next motion (III-C) of the rod;
(III-B) the rod is raised slightly (relative to the platform, sweater and tape), such that it will just clear the tape, without damaging the sweater, in the next motion (III-C);
(III-C) the rod moves parallel to the platform over the top of the tape; drawing a portion of the sweater with it both above and below the rod, while the portion of the sweater under the tape does not move, thus creating a first fold at the distal edge of the tape;
(III-D) the rod continues moving until it reaches the second fold position (although in some embodiments and some folds it continues past this position);
(IV-A) the rod moves parallel to the platform in the opposite direction, returning to the pre-fold position; it continues to rotate in the same direction as in (II) above, unless a snag is detected, in which case rotation is reversed; at this point the sweater has two folds: one at the first fold position as defined by the tape and a second fold position defined by the maximum movement of the rod in step (III-D);
(V-A) the tape retracts;
(V-B) additional folds may be created to repeating steps starting at (I-A).
The phrase, “the rod is close to the tape” means that the rod is as close to the tape as possible such that the fabric between the rod and tape is free to slide freely over the rod as the rod moves without damage to the fabric.
Some embodiments have a single rod and tape.
A preferred embodiment has a second rod and tape, where these are parallel to the first rod and tape. This second rod-tape pair may be used to create folds on the opposite of the garment from the first side.
A preferred embodiment has a third rod-tape pair, positioned orthogonal to the first one or two rod-tape pairs, used to create folds orthogonal to those created by the first one or two rod-tape pairs.
Typically, after the first side of the sweater is folded, then the second side is folded. The sweater now has a number of folds, all parallel to the sweater's primary axis, which we refer to as “side folds.”
Optional third and fourth rod-tape pairs are used to create folds at a right angle to the side folds. We refer to these as “body folds.”
Some of the above steps may be combined. For some folds, some steps may be omitted.
In some embodiments, folds are created at a suitable angle, such as 45°, from the side folds. For example, a sleeve may be folded near the shoulder at approximately 45° to place the length of the sleeve parallel to the primary axis of the article.
In one embodiment, the operator may now remove the folded sweater from the platform. In another embodiment, the invention removes the sweater from the platform automatically. The platform may tilt; or the rods may be used to lift and move the sweater; or another mechanism may move the sweater towards an output area, which may be to hold the sweater while the next article of folded, or may be a moving belt, or may be held on the platform so as to make it easy to pass a bag over the folded article and remove the bag and folded article together, for example.
In some embodiments, the operator first places the article on a “shroud” separate from the platform. The invention then moves the article of the platform so that the article is then resting on the platform.
It is a valuable feature of this invention that the rotating, moving rods also serve to remove wrinkles from the fabric of the article, and to generally straighten the article as it is folded (or, in some embodiments, prior to folding). It is a unique feature of this invention that folding and de-wrinkling occurs with the same mechanism. In some embodiments, a fluid is passed through the rod onto, into, or through the article, which may assist in dewrinkling. For example, steam may be used, exiting the rod through a series of holes. Air may be passed through the rod to aid in keeping the fabric flowing smoothly over the rod while being folded. Hot air may be used to dry an article, while it is being folded. Chemicals may be passed through the rod to aid in sanitizing or odorizing the article. Chemicals or compounds may be passed through the rod where the chemicals or compounds are used to treat the article, such as to set dye, or to treat the fabric to control bacteria and odors, such as nanoparticles of silver.
In some embodiments the direction of rotation of the rod reverses. It is advantageous in some instances to have the rod spinning opposite the direction of horizontal motion (at the point of fabric contact above the rod) when the rod is below the fabric, as this tends to smooth and de-wrinkle the fabric. It is advantageous to have the rod spinning with the direction of horizontal motion (at the point of fabric contact above the rod) when the rod is between two layers of fabric, as this tends to drag the upper material with the rod evenly. In some embodiments, rotation of the rod at the upper contact with the fabric is slightly faster than the horizontal motion of the rod. Note that spinning the rod, may, in some embodiments, assist in keeping the rod straight, permitting the use of a more flexible rod that would be ideal if the rod were not spinning. However, multiple rod spin directions are not always required. In some embodiments, the rod vibrates, instead of spins. Reversing spin direction is desirable if a snag or foreign object or contamination is detected. A very smooth rod may not require spinning. Static charge may be used, in some embodiments, to assist in keeping fabric and fabric threads away from the rod, avoiding friction, drag, wear, and possible snags.
A unique feature of this invention is that in some embodiments it is smaller, at least in one dimension that the fully extended article to be folded. For example, the sweater arms may initially hang off the side of the platform.
Multiple rod-tape pairs permit faster folding operation as more than one fold may be in process at once. Also, a subsequent fold may initiate immediately after an earlier fold because the rod-tape pair has been pre-positioned for that subsequent fold.
Speed of operation is commercially critical, as a single operator should be able to precisely fold more clothes per minute using the invention than the operator would be able to fold by hand.
In another embodiment, the rod retracts after step (III-D) above, in a third direction of motion (not counting rotating), so as to leave both the tape fold and the rod fold intact.
In some embodiments, air, steam, water, chemicals, fragrance, or nanoparticles (referred to as “rod fluids”) are dispensed into or through the article as it is folded, via a the rods, the rods being hollow with openings in the rod for the rod fluid to exit the rod one or more surface locations on the article. These fluids may clean, sterilize, de-scent, de-wrinkle, press, or chemically treat the article while it is being folded. Such actions reduce or eliminate steps.
Various embodiments of this invention are most applicable for article manufacturing, retail stores, hospitality facilities, laundromats and dry cleaners, and home use, depending on embodiments, features, size, flexibility, speed, ruggedness, and cost.
Additional extensions and features of this invention include automatic identification, inspection, scanning, tagging, and packing articles. Machine learning may be incorporated to improve performance and article recognition. RF-ID transponders in article tags are one method of automatically identifying articles.
Worn, contaminated, or damaged articles may be detected either by sensors on the invention of by detecting that the necessary force or torque on a tape or rod is excessive (for any motion of the tape or rod where it might be in contact with the article). Such article may then undergo a difference series of actions than a non-worn, non-contaminated, undamaged article. Examples of such problems include hair, gum, sticky spots, tangled fabric, tears, pins, loose buttons, loose threads, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A , 1 B, 1 C, and 1 D show the sequence of steps in one embodiment of a shirt being folded.
FIG. 2A shows one rod and a motor for spinning the rod.
FIG. 2B shows a tape partially retracted.
FIG. 2C shows one embodiment of a tape end.
FIG. 3 shows a rod and a tape, along with their respective directions of motion relative to a fabric article to be folded.
FIG. 4 shows an embodiment with two rod-tape pairs in one axis and a third rod-tape pair in another axis.
FIG. 5A shows a fabric article placed on a curved support platform.
FIGS. 5B and 5C show outlines used to assist operators in placing articles on a support platform.
FIG. 6 shows an overhead view of one embodiment.
FIG. 7 shows a side view of one embodiment.
FIG. 8 shows an enclosure for one embodiment and a shroud.
FIGS. 9A and 9B show two snapshots in an exemplary folding sequence.
DETAILED DESCRIPTION
FIG. 1A shows a fabric article, here a long-sleeve shirt, in a position to be folded. 1 is the shirt prior the start of folding. It is helpful to consider the shirt sitting roughly horizontally on a platform or table, with a Y-axis through the collar along the primary axis of the shirt; an orthogonal horizontal X-Axis, and vertical Z-axis normal to the X-Y plane on which the shirt lies. The views in FIGS. 1A through 1D are overhead views, looking down. 2 is the first fold line, which is parallel to the Y-axis. A tape (not shown in this Figure) moves over the shirt and then contacts from the shirt the shirt from above so that it's distal edge is aligned with the shown fold line 2 . Contact with the shirt may be achieved in three ways. First, the tape may lower to touch the shirt. Second, the platform supporting the shirt may rise to meet the tape. Third, the tape may already be at the correct height (above or on the fabric); as the tape is extended it glides over the surface.
Refer now to FIG. 1B . Described elsewhere is the precise sequence of steps to accomplish one fold or a pair of folds. Here a rod (not shown in this Figure) is under the left side of the shirt (where “left” is as the viewer looks at this Figure), under the fabric, lifting up the fabric distal to the fold line 2 , then moving to the right over the top of the tape, to the second fold line 6 . This operation creates two folds: a first fold at 4 , comprising the body of the shirt, and a second fold at 5 , in the left sleeve. The partially folded shirt is 3 . The tape, which defined the first fold at 4 , now retracts.
FIG. 1C shows the shirt, 7 , after the second set of two folds. These are accomplished similar to and symmetrically to the first two folds on the left side of the shirt, as shown in FIG. 1B , but are now on the right side of the shirt. In one embodiment, a second rod-tape pair is used to accomplish these two folds. 8 , a fold in the body of the shirt is the third fold position. 9 , in the right sleeve, is the fourth fold. Dotted line 10 , parallel to the X-axis, shows the position of the fifth fold. In one embodiment the fifth and six folds are accomplished by a third rod-tape pair.
FIG. 1D shows the shirt 11 fully folded, after the fifth and sixth folds. 12 shows the fifth fold position while 13 shows the sixth fold position. The fifth and sixth folds are orthogonal to the first through the fourth folds, in this example.
The final shirt, 11 , is in the form of a rectangle. The locations of the first and second fold positions ( 4 and 5 , respectively), and the fifth and sixth ( 12 and 13 , respectively) fold positions are generally selectable to create a desirable final size and shape of the folded article. Generally, the first and forth fold positions are similar, as viewed against the X-Y plane, as are the second and third fold positions. However, this is not necessary.
FIG. 2A shows an exemplary rod with an exemplary motor to spin the rod. The rod is 21 . Rods may be solid or hollow. The rod should be reasonably rigid so that it need be supported at only one end. It should be a low-cost, non-corrosive material that will not damage the fabric articles. A suitable rod material is ¼″ diameter solid aluminum. Smooth polypropylene is another suitable material. The length of the rod should be long enough, in most embodiments, to reach across the article to be folded. The end of the rod should be blunt, 22 , so as to not damage the article. Here, three holes, 23 , are shown in a hollow rod. A rod fluid, such as air, steam, fragrance, or many other fluids, may be moved through the rod and then onto or through the fabric. A motor, 24 , may be an electric motor, here shown with electric leads, 25 . It is advantageous to be able to reverse the motor direction. Here, the motor shown is a DC motor; direction may be reversed by changing the direction of current through the leads 25 . Alternatively, motors may be hydraulic, wind up, or remotely connected to the rod through a mechanical or magnetic coupling.
FIG. 2B shows a partially retracted tape, 28 . The concave-convex tape is bi-stable in that it has one cross-sectional shape when extended and a different cross-sectional shape when coiled in the receptacle 26 . The tape may be efficiently coiled inside the receptacle, 26 . The basic mechanical design of the tape and receptacle is similar to a common tape measure. Note, however, that no measurement markings are required on the tape, and that the end of the tape must be smooth so as to not catch or damage the fabric during either extension or retraction. Note also that the extension and retraction of the tape are powered, as the extension and retraction are key steps in the automatic operation of this invention. Extension and retraction may be achieved by rotating the spool around which the tape is wound, 27 . Alternatively, the tape may be extended and retracted by the use of one or rollers or capstans (not shown), such as a rubber pinch roller. A device, such as a motor, for these purposes, is not shown. The end of the tape is shown, 29 . However, the end of the tape 29 should not be square or sharp, but should be rounded, as will be discussed below, so as to glide smoothly over the fabric during both extension and retraction. 30 shows the point at which the tape 28 enters the receptacle 26 .
A key feature of one embodiment is that the concave-convex tape is concave downward, when extended. This is “upside down” compared to the general use of most tape measures. For a tape measure, the tape is concave upward when extended to provide strength against gravity collapsing the extended tape. For this embodiment, the tape is concave downward to permit pressure to be applied between the article to be folded and the tape. From the view of the tape, this pressure is upwards. Note that the tape must be rigid enough to be self-supporting against gravity when extended, even though it is “upside down.” In some embodiments the tape receptacle may be placed conveniently out of the way, such as below the support platform. One or more rollers may then be used to direct the tape between its receptacle and its extended position above or on the fabric article. A suitable tape material and dimensions are similar to, although in some embodiments stronger, than a common, heavy-duty, measuring tape. For example, coated or painted spring steel, ¾ inch wide, 20 thousands of an inch thick, about the same length as the rod in the rod-tape pair.
FIG. 2C shows an exemplary rounded tape end, 31 . This tape end may be smooth, molded plastic such as a polyamide. The rounded tape end may be secured to the tape with a press fit or an adhesive. Here is shown the blunt, final end, 33 , and an opening, 32 into which the end of the metal tape (shown as 29 in FIG. 2B ) is inserted.
FIG. 3 shows an exemplary arrangement of a rod-tape pair positioned over an exemplary article to be folded, here a shirt, 43 . In this embodiment, there are two rails, a right rail 41 and a lower rail 42 . These rails support the rods and tapes, and provide the mechanical mechanisms to provide the motions of the rods and tapes. Not shown in this Figure is a platform to support the fabric article. Not shown in this Figure is a mechanism to raise and lower the platform. One rod is shown, 44 , and one tape, 45 . The tape, 45 , is its extended position. Note, again, that we often refer to rod-tape pairs for convenience, however, the rods and tapes may be operated completely independently, and an embodiment does not need an equal number of rods and tapes. For the embodiment shown in this Figure, consider that the shirt shown, 43 , is flat and horizontal. The primary axis of the shirt will be known as the Y-axis. Orthogonal to the Y-axis, but still horizontal is the X-axis. The Z-axis is vertical in this embodiment. The rod 44 is parallel to the X-axis. It has three motions: First, horizontal motion along the Y-axis, 46 . Second, rotation, 47 , including the ability to reverse rotation. Third, vertical motion along the Z-axis, 48 . This vertical motion 48 may be implemented by raising or lowering the platform (not shown) on which the article is sitting. The tape 45 is generally parallel to the rod, 44 . However, in some embodiments the tape and rod are not parallel. The tape 45 has three motions. First, horizontal motion along the Y-axis, 49 . Second, extension and retraction, 50 . When retracted, the end of the tape is clear of the article, 43 . Third, vertical motion along the Z-axis, 48 . This vertical motion 48 may be implemented by raising or lowering the platform (not shown) on which the article is sitting. Tapes may be mounted on the platform.
FIG. 4 shows an embodiment with three rod-tape pairs. The right frame 41 supports and provide motions for two rod-tape pairs, while the lower frame supports and provides motions for the third rod-tape pair. The first rod tape pair is 61 and 62 , respectively. The second rod tape pair is 63 and 64 , respectively. The third rod tape pair is 65 and 66 , respectively. All three tapes, 62 , 64 and 66 , are shown in their extended position. Motions of the various rods and tapes must be coordinated to avoid interference. In this embodiment, there are two rails, a right rail 41 and a lower rail 42 .
FIG. 5A shows an article support platform 71 with an article placed on it 72 . In this embodiment, the article support platform is circular and curved, with the center higher in a smooth, convex shape. This shape helps assists the user in centering and aligning an article 73 for folding. The concave surface allows the outer portions of the garment or article to drape slightly, due to gravity, spreading the article. Many other platform shapes are possible, including rectangular and flat. Here, a circle at the center of the platform, 72 , assists a user in centering the article.
In one embodiment, a portion of the platform may lower between the time that a user places an article and the time the folding operation begins. This allows a user to place an article on a smooth, easily accessible platform, possibly raised for convenience. Then, the article is lowered into the invention in an area where the folding steps occur. In FIG. 5A , the center portion 72 may move separately from the outer portion 71 . Note that the shown dimensions are not to scale. In one embodiment the article to be folded is “sucked into” the folding portion of the machine. A vacuum table or portion of a vacuum table may be used. In other embodiments the platform changes shape, elevation or form in order to provide both a convenient table on which a user may place an article and also provide a suitable work surface for the folding steps.
In some embodiments the article to be folded in placed directly on the platform or table used for the folding steps. In other embodiments, the article is first placed on a “shroud,” or other surface, and then transferred to the folding platform. The surface in FIG. 5A may be either a shroud or the folding support platform.
FIGS. 5B and 5C show exemplary outlines of articles to be folded. In one embodiment, one or more of these outlines are visible to users. Such outlines assist the user in proper or optimum placement of articles to be folded. Of particular importance is that the article is centered left-to-right so that the folding is symmetric, and that the article's axis is aligned with the primary folding axis, so that the fold lines are parallel to the articles primary axis. These outlines may be painted on the platform or shroud, or molded, or otherwise visible. In some embodiments, the outline is dynamically alterable. For example, the user may select a long-sleeve shirt to folded, rather than trousers. The invention then provides the outline 74 shown in FIG. 5B rather than the outline 75 shown in FIG. 5C . Such an outline may be projected from above, projected from below, or lit internally. For example, the outline may be translucent plastic embedded in an opaque platform. More than one such outline is embedded, however only one such outline is illuminated at a time. Note that the rear tag and the front fly is visible on outline 75 in FIG. 5C . These indicate an orientation that is “face-up.” Visible buttons or a zipper are examples of such “face up v. face-down” orientation on an article outline. Alternatively, and image of a tors, mannequin or face may be included to provide such face-up v. face-down orientation. Such orientation symbols are helpful in some embodiments to produce a set of desirable final folds.
A variation of FIGS. 5B and 5C is the use of a torso or partial torso outline, symbol or representation. An outline or partial outline of a mannequin may be used. For example, a user may then place the article to be folded on this outline as if “dressing” the torso, partial torso, or outline.
FIG. 6 shows an overhead view of one embodiment. The platform or table is 101 . As shown, the table is generally horizontal (although it may be tilted) and defines and X-Y plane. Normal to the table is the Z-axis, where up is towards the viewer in this Figure. Two orthogonal rails, long side 102 , and short side 103 , are shown. These rails typically support and provide motion for the rods. This embodiment uses four rod-tape pairs. The four rod motors are 104 , 105 , 106 , and 107 . The rod motors spin four rods, 113 , 114 , 115 , and 116 , respectively. Ideally, these motors are reversible. Ideally, these motors have a mechanical, electric, electronic, or hydraulic clutch that provides a maximum rotational torque to avoid damaging the article in the event of a snag or contamination. The form of this clutch may be electronic or partially implemented in software using either the measurement of the motor current or measurement or the rotational speed, or both, to determine the effective resistance against the rotating rod. Four tapes are shown, 108 , 109 , 110 and 111 , which may be considered part of four rod-tape pairs: 104 - 108 , 105 - 109 , 106 - 110 , and 107 - 111 . However, rods and tapes may be fully independent. In this exemplary embodiment, the four tapes are mounted on the table, 101 . The four rod motors spin in either direction. The two rod motors 104 and 105 move along rail 102 in the X-axis. The two rod motors 106 and 107 move along rail 103 in the Y-axis. The rods and the rod motors may not move together. For example, a rod motor might spin a pulley, which then indirectly spins its rod. The tapes extend and retract. The tapes move in the Z-axis up and down. In some embodiments, the tapes also move in the X-Y plane. The table moves up and down. In practice, consideration must be given to mechanical interference of all components.
FIG. 7 shows a side view of one embodiment. The enclosure and most supporting frame elements are not shown. The long side rail 102 is shown, along with an end view of short side rail 103 . Here the table 101 in a high position. The table may be raised and lowered by a variety of mechanisms, here a driven screw, 122 . Mounted on the table, 101 , are four tapes. Three of these tapes are visible, 108 , 109 and 111 . Tapes 108 and 109 are shown in end-view. Tape 111 is shown in side view, with its tape, 121 , extended over the table, 101 . After an article to be folded is placed on the table, 101 , the table moves to a first elevation position. Generally, the first folds are long folds, folding the sides of the garment inward. Rod 116 driven by motor 107 would be used, along with tape 111 , for this purpose. The first elevation position for the table is just below rod 116 . When the folds at the first elevation are completed, the table 101 lowers to a second elevation. At this second elevation the top and bottom of the garment are folded. This second elevation is just below rods 104 and 105 , shown in the Figure in end view. Folds at this second elevation typically use rods 104 and 105 , and tapes 108 and 109 . Typically, the table, 101 , then moves to an appropriate elevation to discharge the completely folded article, or have it manually removed.
FIG. 8 shows an enclosure for the mechanical elements of the invention, in one embodiment. The enclosure is 91 . Either the table rises to the top of the enclosure 91 to accept an article to be folded, or a shroud is used, 92 , to accept the article, which is then transferred to the folding table. An outline of the article may be visible, 93 , to assist the user in placing the article. This outline may be painted, projected, or backlit, as examples. More than one outline may be available, dynamically selected, based on the type of article to be folded. After the article is placed, the user indicates that folding should start, for example, by pressing a “FOLD” button, 94 . For safety reasons, the machine should stop if a hand or other foreign object is placed within the enclosure, 91 . For this reason a protection zone, 95 , is provided. This zone may also comprise mechanical clearance between the table or shroud, 92 , and the sides of the enclosure, 91 .
FIGS. 9A and 9B show two snapshots of an exemplary folding sequence. Prior to the snapshot of FIG. 9A , the sweater 131 is placed; the tape 132 extends over the sweater 131 and lowers onto the sweater to hold it. As described elsewhere, note that the edges of tape 132 face the sweater 131 . The sweater 131 is over the rod 134 , rotated by the rod motor 135 . 133 shows the tape spool and spool enclosure, as described elsewhere. Thus, we see in FIG. 9A the point at which folding is about to begin. The rod 134 will move close to the tape 132 ; then slightly upward such that the sweater material is between the tape 132 and the rod 134 , then the rod 134 will move horizontally in the direction of the arrow 139 over the top of the tape 132 , pulling some of the sweater 131 , including the left (as facing the sweater in this Figure) sleeve to the right, as shown by the arrow 139 . The pressure of the tape 132 against the sweater 131 holds the fabric between the tape 132 and the platform (not shown) securely such that it is not pulled laterally by the rod 134 .
In FIG. 9B we see the result of the motion described above. The tape 132 is in the same location as in FIG. 9A . The rod 134 has moved to the right, creating two folds: a first fold 136 defined by the distal edge of the tape 132 ; and a second fold 137 defined by the distal edge of the rod 134 . Again we note the rod rotation motor 135 and the tape spool and enclosure 133 . A this point in the folding sequence, the rod's 134 direction of rotation may reverse, as driven by the rod motor 135 , then the rod may move out from under a portion of the sweater by moving in the opposite horizontal direction; that is, opposite to arrow 139 . Also the tape 132 retracts into the spool 133 . This latter rod motion and tape retraction steps may occur in either order, or at the same time. As a result of these folding steps, the sweater's left sleeve 138 , has been neatly folded on top of the body of the sweater, 131 .
Note that the sweater 131 , the tape 132 , and the rod 134 are not to scale in FIGS. 9A and 9B . Neither are these two Figures perspective-accurate.
In one embodiment a second rod-tape pair, with the rod starting under the sweater, then makes a second pair of folds, parallel to the two folds described above.
In one embodiment, a third, and possibly a fourth rod-tape pair, orthogonal in orientation to the first two rod-tape pairs, create one, two or more folds orthogonal to the folds 136 and 137 shown in FIG. 9B .
Sensors are an integral part of practical machine operations. Table I below lists an exemplary set of sensors.
TABLE I
Sensors
No of
No of Sensors
Sensor Purpose
Devices
of this type
Rod First limit
4 Rods
4
Rod Second Limit
4 Rods
4
Rod Position
4 Rods
4
Tape First Limit
4 Tapes
4
Tape Second Limit
4 Tapes
4
Tape Extension
4 Tapes
4
Tape Retraction
4 Tapes
4
Tape Position
4 Tapes
4
Tape-on-Article Contact
4 Tapes
4
Table First Limit
1 Table
1
Table Second Limit
1 Table
1
Table Position
1 Table
1
Fabric Placed Yes/No
1 Table
1
Fabric Thickness
Variable
1 or more
Safety (Hand in machine)
Variable
1 or more
TOTAL
42 or more
In some embodiments, a single sensor may provide more than one function as listed in Table I. In some embodiments, a physical stop may be used in place of a limit sensor. In general, limit sensors and safety sensors provide a binary output. In general position sensors provide a numerical output, which may be either analog or quantized (i.e. digital). In some embodiments, it is advantageous to know the thickness of the article, both prior to folding and during folding. Similarly, it is often advantageous to know when a tape has come in contact with the article. As those trained in the art appreciate, sensors may be mechanical, optical, use reflected IR, machine vision, electrical conductivity, encoder disks, tilt switches, and numerous other sensor technologies. As one example, a single machine vision sensor could provide the necessary information to implement a many of the sensors listed in table I, above. Additional sensors are used in some embodiments.
Operation of the machine may be guided by machine vision. A camera and machine vision software may be used to determine the centerline of an article, its outline, the type of article, rotation of the article, and foreign objects. The machine may be directed based on this information, or a warning to the user may be provided. A weight scale may be used to determine if the article is reasonably centered by the user prior to the start of folding.
Mechanisms to move the rods, tape and fabric support platform include but are not limited to: a motor, including electric, wind-up, or pneumatic; a motor attached to a screw drive or wheel; a cable on a driven wheel; with the cable attached to the moving element; air or pneumatic powered, such as by means of a piston. Return motions may be similarly powered, or may be via a spring, pneumatic pressure, or gravity. Such mechanisms may involve use of tracks, gears, levers or belts. It is not necessary that the tape coil in its retracted position.
DEFINITIONS
Article—A foldable article of fabric, such as foldable clothing, napkins, towels, pillow cases, sheets, blankets, tarps, flags, table cloths, and the like.
Concave-convex tape—A tape that when viewed from the end is curved. When the tape is extended in a straight line its preferred bend is concave. When the tape is rolled the curve flattens or reverses. Such bi-stable tapes are commonly used in tape measures. Note that the use of the tape in this invention is “upside down” from the most common orientation of such measuring tapes.
Distal—More distant from the center of the article.
Fabric—Includes woven material, cloth, and non-woven material.
Foldable clothing—Foldable clothing comprises a large number of name articles, without limitation, including shirts, blouses, pants, trousers, leggings, sweaters, jackets, dresses, skirts, gowns, ties, scarfs, tights, nylons, socks, under garments, and many more.
Primary axis of wearable clothing—For clothing for the torso, through the center of the neck. For pants, through the center of the waist.
Ideal, Ideally, Optimum and Preferred—Use of the words, “ideal,” “ideally,” “optimum,” “optimum,” “should” and “preferred,” when used in the context of describing this invention, refer specifically a best mode for one or more embodiments for one or more applications of this invention. Such best modes are non-limiting, and may not be the best mode for all embodiments, applications, or implementation technologies, as one trained in the art will appreciate.
May, Could, Option, Mode, Alternative and Feature—Use of the words, “may,” “could,” “option,” “optional,” “mode,” “alternative,” “typical,” “ideal,” and “feature,” when used in the context of describing this invention, refer specifically to various embodiments of this invention. Described benefits refer only to those embodiments that provide that benefit. All descriptions herein are non-limiting, as one trained in the art will appreciate.
All examples are sample embodiments. In particular, the phrase “invention” should be interpreted under all conditions to mean, “an embodiment of this invention.” Examples, scenarios, and drawings are non-limiting. The only limitations of this invention are in the claims.
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A rotating rod in combination with a retractable concave/convex tape creates pairs of folds on a fabric article on a horizontal platform. A machine and method are described. The tape extends outward and downward to hold the article at a first fold location, while the rotating rod moves from below, then over and across the tape, pulling the fabric with it to create a second fold at the farthest motion of the rod. These motions are typically repeated on the other side of the article, then at right angles, created a finished, folded article of a generally rectangular shape.
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to a highly compressible soft asbestos free gasket material and a method of manufacture thereof. Specifically, this invention is directed to a gasket material which is comprised of fibrillated aramid fibers, diatomaceous earth, a phenolic resin and either a polyethylacrylic or polybutylacrylic latex alone or in combination with various processing agents, the gasket material being free of asbestos fibers.
(2) Description of the Prior Art
For many years, gasket materials for many important uses have contained asbestos fibers. Asbestos fibers have been uniquely suited for gasket materials because of their ability to impart to the gasket material critically important performance and structural features such as heat resistance, good sealability and desirable mechanical properties such as compressibility, creep resistance and tensile strength. When it has been necessary that a gasket material have a high degree of resistance to acids and alkalis and have a high degree of compressibility, African blue (crocidolite) asbestos was used in place of the white (chrysotile) asbestos. The use of asbestos fibers has always been desirable because of their ready availability and low cost.
Recent concerns about the health hazards associated with exposure to asbestos fibers have resulted in concerted efforts to produce asbestos-free gasket materials. However, this highly desirable objective has not been achieved merely by substituting other fibers for asbestos fibers.
Asbestos-free gasket materials are disclosed in U.S. patent applications Ser. Nos. 953,445; 170,743; and 259,984, which are assigned to the assignee of the present application. The gasket materials of the above-identified co-pending applications are suitable for replacing the prior gasket materials which contain the white (chrysotile) asbestos. While the gasket materials disclosed in the above-identified co-pending applications exhibit substantially similar characteristics and properties to those prior gasket materials which contain white asbestos, they do not possess the greater resistance to acids and alkalis which are characteristic of gasket materials containing African blue (crocidolite) asbestos, nor do they possess an equivalent degree of compressibility.
Furthermore, it has not been proven possible to merely substitute other fibers for the African blue asbestos fibers and still achieve a gasket material of comparable characteristics. By way of example, the substitution of cellulose fibers for crocidolite asbestos will produce a gasket material which will not function effectively at temperatures up to 500° F. and will not possess an acceptable resistance to alkalis.
SUMMARY OF THE PRESENT INVENTION
The present invention overcomes the above-discussed disadvantages and other deficicencies of the prior art by providing an asbestos free gasket material which has the desired acid and alkali resistance and high compressibility of prior art African blue (crocidolite) asbestos containing gasket materials and which functions effectively at temperatures up to 500° F.
In accordance with the present invention a gasket material is formed from a material comprised of a fibrillated aramid fiber, diatomaceous earth, a phenolic resin, and either a polyethylacrylic or polybutylacrylic latex alone or in combination with conventional curatives, antioxidants and pigments. The resulting gasket material has substantially the same acid and alkali resistance and degree of compressibility which characterize prior art gasket materials containing African blue (crocidolite) asbestos and the gasket material of the present invention functions at temperatures up to 500° F.
The term fibrillated as utilized herein shall mean the partial cleavage or separation of an aramid filiment into fibrillar fragments which remain mechanically attached to the main fibril.
Compressibility, as used with respect to gasket materials, refers to the percentage of thickness deformation from the free state thickness to the resulting thickness when subjected to a standard compressive load of 5000 p.s.i. The standard definition of varying degrees of compressibility are as follows:
______________________________________COMPRESSIBILITY THICKNESS DEFORMATION______________________________________Low 10%Medium 20%-30%High 40% and above______________________________________
The aramid fibers which are useful in the practice of the present invention are chemically composed of a poly p-phenylene terephthalamide with the chain configurations extended.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is an improvement over the asbestos-free gasket materials disclosed in U.S. applications Ser. Nos. 953,445; 170,743; and 259,984, which are assigned to the assignee of the present application and are incorporated herein by reference. The gasket materials disclosed in the referenced applications may be utilized as a substitute for prior art gasket materials containing white (chrysotile) asbestos, with the resulting asbestos free gasket material having substantially similar characteristics to the prior art materials. However, the gasket materials of the referenced applications, like gasket materials containing white asbestos, have relatively poor resistance to acids and alkalis. For some uses, particularly in the chemical processing industry, gaskets must be able to withstand exposure to various acids and alkalis and be highly compressible. Up to this time only gasket materials containing African blue (crocidolite) asbestos could be used for gaskets which were to be exposed to either acids or alkalis.
The present invention provides a highly compressible gasket material which has high resistance to acids and alkalis and also functions effectively as a gasket material at temperatures up to 500° F.
The present invention provides a gasket material which is comprised of fibrillated aramid fibers, diatomaceous earth, a phenolic resin and either a polyethylacrylic or polybutylacrylic latex alone or in combination, with conventional curatives, antioxidants, and pigments. The chart below discloses the permissible and preferred variations in proportions of the above-identified constituents.
______________________________________ PERCENTAGE OF TOTAL SOLIDSCONSTITUENTS Permissible Preferred______________________________________Fibrillated Aramid Fibers 5-40 10-15Diatomaceous Earth 25-85 60-75Phenolic Resin 0.5-10 2-5Polyacrylic Latex ofeither ethyl or butylacrylates alone orboth in combination 5-25 7-22Curatives, Antioxidents,Pigments 1-10 2-5______________________________________
As stated above, the aramid fibers useful for the practice of the present invention are chemically composed of poly p-phenylene terephthalamide with the chain configurations extended. The resulting fibers have a high modulus and tensile strength. The essential characteristics of these aramid fibers is their capability of being fibrillated and their inherent high thermal stability. The preferred method of fibrillation of these aramid fibers is the mechanical shearing of the fibers in a water slurry which is commonly referred to as beating or refining. This fibrillation of the aramid fibers increases their surface area 40 to 50 times which enables the use of less fibers by weight. Furthermore, fibrillated aramid fibers act as a filter medium during the processing on paper making equipment and also increase the strength of the finished product by forming an entangled fiber structure which increases the retention of the diatomaceous earth in the finished product.
Diatomaceous earth suitable for use in the practice of the present invention should be of a particle size ranging between 1-100 microns and have less than 5% organic content. A phenolic resin suitable for use in the practice of the present invention may be synthesized by reacting 9.45 moles of phenol with 19.4 moles of an aqueous formaldehyde solution. The use of a phenolic resin in conjunction with a polyacrylic latex provides a gasket material in accordance with the present invention with improved torque (creep relaxation) retention at elevated temperatures, compressive strength and resistance to acids, alkalis, solvents and alcohols.
The polyacrylic latex is comprised of either ethyl or butyl acrylates, alone or in combination, and a small amount of acrylonitrile to cross link the acylates. The amount of the acrylates and acrylonitrile composition should be such to achieve the desired characteristics of the final product. Too much of the acrylates will result in a product that is elastic (thermoplastic) and not possessing the desired compressibility. Too much of the acrylonitrile will result in a hard product due to excessive cross-linking of the acrylates. The preferred percentage by weight of solids of the polyacrylic is 90% of either the ethyl or butyl acrylates alone or in combination and 10% of the acrylonitrile, which has approximately 3% cross-linking monomers. The latex composition itself should preferrably be a 50% emulsion of the polyacrylic solid in water. However, the percentage by weight of the polyacrylic solid may vary between 1% to 70%. Alcohol/water systems may also be used as the emulsion medium in the practice of the present invention.
In order to obtain the desired physical properties in the final product and to allow processing on paper making equipment, the fibrillated fibers should have a length ranging between one half to four millimeters, preferably approximately two millimeters, and a diameter ranging between 0.001 to 0.0035 millimeters. It is also important to have the fibers available in a "wet lap" form for processing on paper making equipment. A wet lap form refers to an incomplete drying of the aramid fibers after being fibrillated. This "wet lap" form allows the fibers to be redispersed in water at concentrations of one half to four percent. An aramid fiber well suited for the use in the practice of the present invention is sold by E. I. duPont de Nemours & Co. under the trademark KEVLAR 979 pulp.
The following are examples of various percentages of the constituents, by weight, in a material prepared in accordance with the present invention:
EXAMPLE 1______________________________________ PERCENTCONSTITUENT OF TOTAL SOLIDS______________________________________Aramid Fibers (KEVLAR 979) 11.95Diatomaceous Earth(CELITE 321, availablefrom Johns ManvilleCompany) 71.74Pigments, Curatives andother conventional processingaids 2.44Phenolic Resin (SL 3224,available from Bordons) 3.11Polyacrylic Latex (Vultex491-5D, availablefrom GeneralLatex Corp.) 10.76______________________________________
EXAMPLE 2______________________________________ PERCENTCONSTITUENTS OF TOTAL SOLIDS______________________________________Aramid Fiber (KEVLAR 979) 10.7Diatomaceous Earth(CELITE 292) 73.5Zinc Oxide 0.5Phenolic Resin (MR 1100,a water dispersable phenolicresin available from RogersCorporation, Rogers, CT.) 3.2Polyacrylic Latex(Vutex 491-5D) 11Blue BH (blue dye soldby Internation Dye StuffCorporation) 1.1______________________________________
EXAMPLE 3______________________________________ PERCENTCONSTITUENT OF TOTAL SOLIDS______________________________________Aramid Fiber (KEVLAR 979) 12Diotomaceous Earth(CELITE 321) 71.7Curatives, AntioxidentsProcessing Aids, Blue Dye 2.4Phenolic Resin 3.1Polyacrylic Latex 10.8______________________________________
The blue dye of Examples 2 and 3 gave the final composition a blue color to more closely resemble the coloration of a gasket material containing the African blue asbestos and was also employed in Example 1. A gasket material was formed from the composition of Example 2 and subjected to various tests. Compressibility was tested by the ASTM F36 testing method for type 1 materials. Recovery of the resulting gasket material was determined by the same testing method. The material was further tested for creep relaxation by the ASTM F38 testing method at 2500 p.s.i. and 350° F. Furthermore, tensile strength of the resulting gasket material was tested by the ASTM F152 testing method.
Table 1 lists the results of these various tests performed upon a gasket comprised of the material composition of Example 2.
TABLE 1______________________________________PROPERTIES______________________________________Thickness (inches) 0.080Density (grams per centimeter) 0.63Compressibility at 5000 psi (%) 34.6Recovery (%) 23.8CD Tensile Strength (psi) 899Creep relaxation at 350° F.,2500 psi, over 20 hours (%) 60.8______________________________________
Table 2 compares a gasket material formed from the composition of Example 3 with a typical prior art asbestos containing gasket material comprised of 78% African blue asbestos, 17% butyl latex and 5% of conventional curatives, antioxidents and processing aids. The tests were the same as described above.
TABLE 2______________________________________ ASBESTOS GASKET CONTAINING MATERIAL OF GASKET THE PRESENTPROPERTIES MATERIALS INVENTION______________________________________Thickness in inches 0.132 0.124Density in gramsper centimeter 0.98 0.57Tensile Strength in psi 508 586Compressibility by per-cent at 5000 psi 42.8 45.8Recovery in percent 27.4 21.8Creep relaxation inpercent at 350° F.,2500 psi for 20 hours 68.1 72.9______________________________________
From Table 2 it is seen that a gasket material prepared in accordance with the present invention has similar properties to a gasket material containing African blue asbestos. Further tests were performed with the gasket material of Example 3 and the above described asbestos containing gasket material to determine certain properties after immersion in a concentrated hydrochloric acid solution (12 N). Tests for compressibility, recovery and tensile strength were conducted as described above. A test to determine the percent of thickness change was performed by the ASTM F146 testing method. Also, the percent of weight change was measured by the same testing method. Table 3 shows the results of these further tests upon the asbestos containing gasket material and the gasket material of Example 3.
TABLE 3______________________________________ ASBESTOS GASKET CONTAINING MATERIAL OF GASKET THE PRESENTPROPERTIES MATERIALS INVENTION______________________________________Percent of compress-ibility at 5000 psi 50.8 50.6Percent of recovery 20.7 17.8Tensile Strength, psi 151 263Percent of thicknesschange 40.4 0Percent of weight change 123 92.8______________________________________
From Table 3 it is seen that the gasket material of the present invention performs similarly or better than the gasket material containing African blue asbestos.
The following Tables 4 and 5 compare an asbestos containing gasket material, as described above, with a gasket material comprised of 12% Aramid fiber, 72% diatomaceous earth, 2.5% curatives, antioxidants, processing aids and blue dye, 3% phenolic resin and 10.5% of a polyacrylic Latex. The properties were determined according to the above mentioned tests. In Table 4 the gasket materials were immersed in the various chemical solutions for 24 hours at room temperature before testing. Table 5 provides a comparison between asbestos containing materials and gasket materials of the present invention when subjected to a temperature of 500° F.
TABLE 4______________________________________ Present Invention Asbestos______________________________________30% HCL SolutionThickness change % 0 41.0Weight change % 94.5 137.6Compressibility @5000 psi % 48.0 52.2Tensile strength psi 300 13530% H2SO4 SolutionThickness change % 0 39.0Weight change % 58.1 175.2Compressibility @5000 psi % 47.5 51.8Tensile strength psi 300 9830% HNO3 SolutionThickness change % 0 38Weight change % 100.5 261.3Compressibility @5000 psi % 49.7 51.8Tensile strength psi 219 795% NaOH SolutionThickness change % 0 40Weight change % 109.8 197.7Compressibility @5000 psi % 52.3 49.4Tensile strength psi 131 70______________________________________
TABLE 5______________________________________ Present Asbestos Invention Containing______________________________________Compressibility Change at1,000 psi, %Material Starting Thickness.062" +5.3 -3.4.125" +1.3 +1.6Compressibility Change at5,000 psi, %Material Starting Thickness.062" +3.6 -4.3.125" +1.3 +1.6Weight Loss, %Material Starting Thickness.062" 13.1 18.2.125" 12.8 17.0Tensile Loss, %Material Starting Thickness.062" 25.7 79______________________________________
Table 6 below compares three different thicknesses of a gasket material of the present invention comprising 12% Aramid fiber, 72% Diatomaceous earth, 2.5% Curatives, Antioxidants, processing aids and blue dye, 3% phenolic resin and 10.5% of a poly acrylic latex before and after exposure to an acid and alkali.
TABLE 6______________________________________Property______________________________________Thickness in. .031 .062 .125Density g/cc .52 .56 .63Tensile strength psi 597.7 608.9 721.2Compressibility @5000 psi % 49.6 46.6 39.0Recovery 15.8 17.3 26.2Compressibility @1000 psi % 30.8 27.4 15.7Recovery 30.7 30.6 48.9H.sub.2 SO.sub.4 (10%) 22 hour immersion at room temperatureTensile strength psi 324.3 337.6 509.1% Loss in tensile strength -45.7 -44.6 -29.4Compressibility @5000 psi % 50.9 50.2 42.7% change in compressibility +2.6 +7.7 +9.5Recovery % 15.8 16.4 23.2% change in recovery 0 -5.2 -11.4NaOH (5%) 22 hour immersion at room temperatureTensile strength psi *88.7 *95.6 157.3% Loss in tensile strength *-85.2 *84.3 -78.2Compressibility @5000 psi % 53.7 53.0 50.7% change in compressibility +8.3 +13.7 +30.0Recovery % 20.4 18.6 24.4% change in recovery +29.1 +7.5 -6.9______________________________________ *Estimated to closest values obtained
While the preferred embodiments have been disclosed and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
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A gasket material comprised of fibrillated aramid fibers, diatomaceous earth and either a polyethylacrylic or polybutylacrylic latex alone or in combination with conventional curatives, antioxidants and pigments. The constituent materials are combined in a beater-addition process, and the pliable gasket material is then formed on conventional paper making equipment.
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This Application is a Divisional of U.S. patent application Ser. No. 10/727,553, filed Dec. 5, 2003, now U.S. Pat. No. 7,139,640, which is hereby incorporated by reference.
The present invention claims the benefit of Korean Patent Application No. 2002-88464 filed in Korea on Dec. 31, 2002, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a substrate transfer system for a liquid crystal display (LCD) device, and more particularly, to a system having an auto guided vehicle provided with a bar code reader and for transferring a cassette in which a substrate is loaded.
2. Description of the Related Art
Generally, an LCD device comprises a TFT array substrate and a color filter substrate bonded together by a sealant with liquid crystal filled therebetween. A liquid crystal display panel is usually formed of a glass substrate. Nowadays, a liquid crystal display panel of large size can be produced. However, it is difficult to transfer the liquid crystal display panel of large size, and therefore, there has arisen a need for a substrate transfer system to transfer a large sized substrate.
In the related art, a substrate is transferred by a cassette in which one or more substrates are loaded. The cassette is transferred to a stage of a corresponding step by an auto guided vehicle. The transfer system comprises a cassette stocker where a substrate cassette is stored; a robot arm for taking out the substrate cassette from the cassette stocker; an auto guided vehicle for transferring the substrate cassette; a rail on which the auto guided vehicle moves; a plurality of stages; and a main computer such as a host for controlling the auto guided system.
The substrate cassette transfer system in accordance with the related art will be explained with reference to FIG. 1 .
First of all, substrates go through various processes, and substrates that have undergone the same processes are loaded in the same cassette and stored in the cassette stocker. That is, for example, substrates which have undergone a process for forming a gate line among processes for fabricating a thin film transistor as a switching device are loaded in the same cassette to be held or stored until next processes.
To perform predetermined processes using the substrates loaded in the cassette stoker, the substrate cassette is loaded on the auto guided vehicle from the cassette stoker. The process is performed by giving an order to the cassette stocker by the host. Therefore, the cassette stocker is provided with a receiver for receiving data from the host. The substrate cassette loaded on the auto guided vehicle is transferred to a process stage where a corresponding process will be performed. The auto guided vehicle moves along a predetermined path and, thus, arrives at a corresponding stage. The corresponding stage may be a fabricating apparatus for an LCD device including a chamber where various processes, for example, the cassette cleaning, sputtering, photo resist formation, etc. are performed.
Each stage includes a shelf for holding the transferred substrate cassette until use. The auto guided vehicle arrives at the corresponding stage and unloads the cassette where the substrate is loaded on the shelf of the corresponding stage using the robot arm of the auto guided vehicle. Also, a bar code reader formed at an arbitrary point of the shelf which is at one side of the stage reads a bar code attached to one side of the cassette to recognize the cassette, and then transmits data to the host. Accordingly, the host determines processes of a corresponding cassette.
If the bar code reader transmits the read information to the host, the host determines which process will be performed for the corresponding cassette and orders the process to progress or stop at the corresponding stage. The substrate which has undergone a specific process on the corresponding stage is reloaded into the substrate cassette. Then, the host calls an empty auto guided vehicle to load the cassette where the processed substrate is loaded and to transfer to the cassette stocker for storage.
However, in the substrate transfer system, the bar code reader has to be respectively provided on each stage, thereby increasing cost. That is, the bar code reader is an expensive device causing increased cost.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a substrate transfer system that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a substrate transfer system having a bar code reader that reads a bar code of a substrate cassette at an auto guided vehicle or a cassette stocker with reduced cost and stable operation.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a substrate transfer system for use in fabricating a liquid crystal display (LCD) device comprises a cassette having a bar code; a cassette stocker to store the cassette; an auto guided vehicle having a bar code reader, the auto guided vehicle being able to transfer the cassette; a moving path unit to determine a moving path of the auto guided vehicle; a plurality of process stages at which processes are conducted on a substrate during fabrication of the LCD device; and a host to control the cassette stocker, the auto guided vehicle, and the process stages.
In another aspect, a substrate transfer system for use in fabricating a liquid crystal display (LCD) device comprises a cassette having a bar code; a cassette stocker to store the cassette, the cassette stocker having a bar code reader; an auto guided vehicle being able to transfer the cassette; a rail disposed along a moving path of the auto guided vehicle; a plurality of process stages at which processes are conducted on a substrate during fabrication of the LCD device; and a host to control the cassette stocker, the auto guided vehicle, and the process stages.
In another aspect, a method for transferring a substrate during fabrication of a liquid crystal display (LCD) device comprises the steps of unloading a cassette having a bar code from a cassette stocker to an auto guided vehicle having a bar code reader; reading the bar code attached to the cassette using the bar code reader; analyzing information from the bar code reader; directing the auto guided vehicle to a stage where a process is to be performed; loading the cassette on the stage; detecting a cassette on which the process has been completed and transmitting the information to a host; directing the auto guided vehicle to the stage where the processed cassette is disposed and loading the processed cassette into the auto guided vehicle; and transferring the cassette to the cassette stocker.
In another aspect, a substrate transfer system of a liquid crystal display (LCD) device comprises the steps of reading a bar code attached to a cassette using a bar code reader disposed in a cassette stocker; loading a cassette from the cassette stocker having the bar code reader to an auto guided vehicle; directing the auto guided vehicle to a stage where a process is to be performed; unloading the cassette on the stage; detecting a cassette on which the process has been completed and transmitting the information to a host; directing the auto guided vehicle to the stage where the processed cassette is disposed and loading the cassette into the auto guided vehicle; and transferring the cassette to the cassette stocker.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
FIG. 1 is a conceptual view showing a substrate transfer system in accordance with the related art;
FIG. 2 is a block diagram showing operation of a substrate transfer system according to the present invention;
FIG. 3 is a block diagram showing operation of a substrate transfer system according to another embodiment of the present invention; and
FIG. 4 is a conceptual view showing a substrate transfer system in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
With reference to FIG. 4 , the present invention contemplates a plurality of cassettes 401 where a plurality of substrates classified according to each process are loaded and stored in a cassette stocker 410 . Also, a robot arm 402 for loading/unloading the substrate cassette 401 into/from the cassette stocker 410 , and a receiver for receiving data from a host 420 may be provided in the cassette stocker 410 .
The auto guided vehicle 403 comprises a cassette loading unit formed at an upper portion of the auto guided vehicle 403 and on which a cassette 401 is placed, a caster arranged at a lower portion of the auto guided vehicle 403 for moving the auto guided vehicle, a caster driving unit for driving the caster, data transmitting/receiving unit for transmitting/receiving data to/from a host 420 by wire/wireless communication, a bar code reader 405 for reading a bar code 404 attached to a cassette 401 , and a robot arm 402 for loading/unloading a cassette 401 on/from a shelf of a corresponding stage 430 . A position detecting sensor 450 for detecting a position of the auto guided vehicle 403 and transmitting the information to the host 420 is mounted, for example, at a predetermined location of a rail which determines a moving path 406 of the auto guided vehicle 403 . The position detecting sensor 450 is generally installed in front of respective stages to stop the auto guided vehicle 403 in front of them. A shelf for loading/unloading the substrate cassette 401 from the auto guided vehicle 403 , and a substrate cassette detecting sensor for detecting the processed substrate cassette 401 are installed on the stage 430 .
The bar code reader 405 for reading a bar code 404 attached to a predetermined position of the cassette 401 is installed in the auto guided vehicle 403 which transfer the cassette 401 . The bar code reader 405 can be installed at the robot arm 402 arranged at one side of the auto guided vehicle 403 . Here, the bar code reader 405 need not be installed on the shelf of each stage 430 .
Operation of the system according to the present invention will be explained with reference to FIG. 2 .
First, the cassette containing substrates that have undergone the same processes is loaded into the auto guided vehicle from the cassette stocker. Of course, it should be recognized that in some circumstances that it may be desired that the substrates have not undergone the same processes. The cassette stocker loads the cassette where substrates having processes to be performed are loaded into the auto guided vehicle by receiving an order from the host. The loading of the substrate cassette is performed by the robot arm installed at one side of the cassette stocker. The auto guided vehicle arrives at a corresponding stage through a moving path, such as a rail that guides the auto guided vehicle.
The position detecting sensor for detecting a position of the auto guided vehicle is mounted at a predetermined location of the rail which corresponds to a corresponding stage, thereby stopping the auto guided vehicle at a precise position and transmitting the position information of the auto guided vehicle to the host. The auto guided vehicle having arrived at the corresponding stage reads the bar code of the loaded substrate cassette by the bar code reader installed at the robot arm located at one side thereof and transmits the information to the host. The host analyzes the information, determines whether the substrates loaded into the auto guided vehicle should have predetermined processes performed or not, and transmits an order to the auto guided vehicle.
If it is determined that the substrate should have the predetermined processes performed on the corresponding stage, the robot arm provided at one side of the auto guided vehicle loads the cassette on the shelf of the corresponding stage. The host analyzes the information received from the bar code, a unique identification mark of the substrate, thereby determining a current process progression state and processes to be performed on the substrate. The auto guided vehicle may wait in front of the corresponding stage while processes are performed on the corresponding stage, or may move to another stage to enhance efficiency of the processes.
The processed substrate on the corresponding stage is reloaded into a waiting cassette, and the cassette detecting sensor of the corresponding stage transmits information to the host that processes of the substrate in the cassette are completed. The host analyzes the transmitted data and calls an empty auto guided vehicle to the corresponding stage. The robot arm installed at the auto guided vehicle loads the processed cassette into the called auto guided vehicle. When the cassette is loaded into the auto guided vehicle, the bar code reader simultaneously reads the bar code attached to the cassette and transmits the information to the host. The host analyzes the information received from the bar code reader and stores process information of the cassette.
Then, auto guided vehicle where the processed transfers the loaded cassette to the cassette stocker thus to store. Herein, communication among the host, the cassette stocker, the auto guided vehicle, and the respective stages is performed by wireless or by wire such as LAN.
As aforementioned, since the bar code reader is installed on the robot arm of the auto guided vehicle to detect the cassette, the number of the bar code reader needed can be greatly reduced as compared to the related art having a bar code reader respectively provided on each shelf of each corresponding stage.
In another embodiment of the present invention, the bar code reader is installed on the cassette stocker. Specifically, the bar code reader is formed at one side of the cassette stocker and installed at the robot arm which loads the cassette into the substrate auto guided vehicle. FIG. 3 explains an exemplary operation of this embodiment of the present invention.
The cassette having the substrate therein is loaded into the auto guided vehicle by the robot arm formed at a side of the cassette stocker. A loading order is given to the cassette stocker from the host via a receiver for receiving the order from the host installed on the cassette stocker. The transmission of the order can be performed by wire or by wireless communication.
The bar code, an identification mark for identifying the cassette, is attached to a predetermined position on the loaded substrate cassette. A bar code reader, installed at a predetermined position of the cassette stocker, reads the bar code and transmits the information to the host. The bar code reader can be installed on the robot arm which loads the cassette into the auto guided vehicle.
The host analyzes the transmitted information received from the bar code reader installed at the cassette stocker and orders the auto guided vehicle to transfer the cassette onto a stage where the substrate is to progress. The substrate stage is loaded into the auto guided vehicle by the robot arm of the cassette stocker, and the auto guided vehicle moves to a corresponding stage.
A position detecting sensor for detecting a position of the auto guided vehicle is attached to one side of the rail at a corresponding stage. Using the position detecting sensor, the auto guided vehicle is precisely positioned in front of the corresponding stage. The auto guided vehicle then unloads the loaded cassette on the shelf of the corresponding stage. The cassette is unloaded by the robot arm installed at the auto guided vehicle.
While the substrate cassette is transferred to the corresponding stage, the auto guided vehicle just transfers the substrate cassette. Whether the substrate loaded in the cassette is to be delivered to next processes or not is determined by the host on the basis of the information read by the bar code reader attached to the cassette stocker.
The substrate cassette unloaded on the shelf of the corresponding stage is processed at the corresponding stage. The auto guided vehicle can wait at a designated position while processes are performed on the corresponding stage, or can move to another stage to enhance efficiency of the processes.
The processed substrates on the corresponding stages are reloaded in the cassette, and wait for the auto guided vehicle on the shelf. A sensor for detecting the processed cassette is attached on the shelf where the cassette in which the processed substrate is loaded is located, thereby detecting the processed cassette and transmitting the information to the host. The host analyzes the information, sends an empty auto guided vehicle to the stage where the processed cassette is located, and loads the cassette into the auto guided vehicle. The auto guided vehicle moves and stores the substrate cassette to the cassette stocker.
As aforementioned, in the present invention, the bar code reader attached to the substrate cassette is installed on the auto guided vehicle or the cassette stocker instead of installing on each shelf of each corresponding stage of the related art. According to this, the number of the bar code readers can be greatly reduced, thereby reducing cost while efficiently achieving, thereby the cassette transfer. Also, the bar code reader is not needed on the stage enhancing an area efficiency.
It will be apparent to those skilled in the art that various modifications and variations can be made in the substrate transfer system of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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A substrate transfer system is used in fabricating a liquid crystal display (LCD) device. The system includes a cassette having a bar code, a cassette stocker to store the cassette; an auto guided vehicle that is able to transfer the cassette; a moving path unit to determine a moving path of the auto guided vehicle, a plurality of process stages at which processes are conducted on a substrate during fabrication of the LCD device, and a host to control the cassette stocker, the auto guided vehicle and the process stages. At least one of the auto guided vehicle and the cassette stocker having a bar code reader.
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BACKGROUND OF THE INVENTION
The present invention relates to a velocity interferometer with continuously variable sensitivity. It is applicable to the study, without mechanical contact, of the movement of an optically reflecting surface or a rough surface able to back scatter an incident light beam. It makes it possible to carry out measurements, even when the state of the investigated surface evolves under a mechanical action (stress, shock) or chemical action (phase change, oxidation).
Velocity interferometers are known called "wide angle MICHELSON interferometers" or "widened field interferometers", which make it possible to perform such measurements. One exemplified construction of such interferometers is diagrammatically shown in FIG. 1. It essentially comprises a laser 2 transmitting, via an e.g. semi-transparent mirror 3, a light beam onto a diffusing surface 4 to be investigated, which can e.g. be moved with the aid of a projectile 5. A beam splitting means 6, which traps the light reflected by the surface illuminated by the light beam, reflects one part thereof and transmits the other part. A first mirror 7 reflects in the direction of the splitting means 6 the light reflected by the same and then transmits the other part. A second mirror 8 reflects in the direction of the splitting means 6, the light transmitted by the same and reflects the other part. There are means 9 for the detection of the interferences resulting from the superimposing of the light from the splitting means 6 after reflection on the first mirror 7 and the light from the splitting means 6 after reflection on the second mirror 8. There is a glass block 10 with parallel faces of length or more accurately thickness L (distance between two parallel faces) and optical index n, interposed between the splitting means 6 and the second mirror 8, the distance from the first mirror 7 to the splitting means 6 being equal to the distance between the latter and the apparent position 11, viewed from detection means 9, of the second mirror 8.
Such an interferometer suffers from the following disadvantages. In order to have a high sensitivity, it is necessary to have a glass block 10 of considerable length (e.g. approximately 1.50 m for detecting velocity variations ΔV less than 30 m/s), which is difficult and costly. In addition, the sensitivity of the interferometer is fixed once and for all by the choice of a glass block, bearing in mind the following relation:
ΔV=1/4λ.sub.0 c L.sup.-1 (n-1/n).sup.-1 ( 1)
in which λ 0 and c respectively designate the emission wavelength of laser 2 and the velocity of light in vacuo.
SUMMARY OF THE INVENTION
The object of the present invention is to obviate these disadvantages.
The invention specifically relates to a velocity interferometer for determining the time evolution of the velocity of an optically reflecting or back scattering surface and which comprises:
a monochromatic, time-coherent light source, arranged so as to transmit a light beam onto the surface to be studied,
a light beam splitting means arranged so as to receive the light thrown back by the surface, while transmitting one part thereof and reflecting the other part,
a first light reflection means for receiving the part reflected by the splitting means and for reflecting it in the direction of the latter, so that it transmits part thereof,
a second light reflection means for receiving the part transmitted by the splitting means and for reflecting it in the direction of the latter, in order that it reflects part thereof, so as to bring about interference between the transmitted part of the light reflected by the first reflection means and the reflected part of the light reflected by the second reflection means,
means for detecting the interferences resulting therefrom and,
a medium with parallel faces located on the path of the light propagated between the splitting means and one of the reflection means and which serves to delay said light with respect to the light propagating between the splitting means and the other reflection means, the latter being made to coincide with the image of the reflection means associated with said medium, given by the latter and the splitting means, wherein the medium with parallel faces is realized with the aid of a fluid in which said reflection means associated with the medium is immersed and displaceable in translation parallel to the path of the light falling thereon and coming from the splitting means and wherein said other reflection means is displaceable in translation parallel to the path of the light falling thereon and coming from the splitting means.
The term fluid is understood to mean a liquid or a gas, other than air and preferably under pressure.
In view of the nature of the medium with parallel faces used by it, the interferometer according to the invention is much simpler and less costly to produce than the aforementioned known interferometer. In addition, the interferometer according to the invention has a continuously variable sensitivity because, according to relation (1), said sensitivity is a function of the thickness of the fluid interposed between the reflection means associated therewith and the splitting means. This thickness is regulatable, because the reflection means immersed in the fluid is displaceable. The mobility of the other reflection means makes it possible to make the latter coincide with the image of the reflection means associated with the fluid given by the latter and the splitting means.
The interferometer according to the invention makes it possible to record velocity variations between a few meters per second and the speed of light, but the measurement dynamics remains linked with the detection means and the geometry of the interferometer chosen by the experimenter. This interferometer can be used in the following fields:
study of fast transient or oscillatory movements (e.g. pistons, valves),
study of the deformation of structural components under dynamic loading,
ballistic study (movement of a projectile, its launcher or the associated target),
study of mechanical or thermal stress waves under elastic or plastic operating conditions with or without fracture under the effect of compression, expansion or tension,
study of the separation of thick or thin layers in composite materials as well as in electronic components and circuits,
study of the shock waves produced by explosives or plate projections,
study of thermal shocks (interaction of photons or particles with the matter) and optionally in astrophysics.
According to a preferred embodiment of the interferometer according to the invention, each of said first and second reflection means comprises a catadioptric system, i.e. a device able to reflect a light beam in the incidence direction thereof, no matter what the said direction. The interferometer according to the invention can then also comprise a first light reflector and a second light reflector, each of them being positioned, with respect to the splitting means and the corresponding catadioptric system, in such a way that the light from the splitting means and which falls on the corresponding catadioptric system is reflected by the latter in the direction of the corresponding reflector and is then reflected by the latter in such a way that it returns towards the splitting means following the path taken by it when it passed from the splitting means to the corresponding reflector.
Preferably, the interferometer according to the invention is produced in such a way that the fluid medium with parallel faces is traversed by vertical light rays.
Preferably, the light source comprises a laser, whose lighting power is such that the flux of light traversing through the fluid medium with parallel faces is at the most equal to 50 mW/cm 2 .
Finally, according to an advantageous embodiment, the detection means comprise a cinematographic recorder or three photodetectors, one controlling the light intensity thrown back by the investigated surface and the other two respectively recording the light intensity at two points, in phase quadrature, of the interference field.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter relative to non-limitative embodiments and the attached drawings, wherein show:
FIG. 1 a diagrammatic view of a known and already described velocity interferometer.
FIG. 2 a diagrammatic view of a special embodiment of the velocity interferometer according to the invention, incorporating a medium with parallel faces produced with the aid of a liquid column, as well as a reflection means displaceable in said liquid.
FIGS. 3 and 4 diagrammatic views of displacement means for said reflection means.
FIG. 5 a diagrammatic view of another special embodiment of the interferometer according to the invention.
FIG. 6 an enlargement of the field of interference fringes which can be observed as a result of the interferometer according to FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 diagrammatically shows a special embodiment of the interferometer according to the invention comprising:
a monochromatic, time-coherent light source formed by means of a laser 12 which, via an e.g. semi-transparent plate 13, transmits a light beam onto a rough surface 14, which is able to back scatter the same and which can be moved or deformed with the aid of e.g. projectile 15;
means 16 for splitting the light beam for receiving the light back scattered by the surface and for transmitting one part thereof and reflecting another part thereof;
a first means 17 for reflecting the light, which serves to receive the part reflected by the splitting means 16 and for reflecting it in the direction of the latter, which then transmits part thereof;
a second means 18 for the reflection of light for receiving the part transmitted by the splitting means 16 and for reflecting it in the direction of the latter, which then reflects part thereof, so as to bring about interference between the transmitted part of the light reflected by the first reflection means 17 and the reflected part of the light reflected by the second reflection means 18;
means 19 for detecting the resulting interferences; and
a medium with parallel faces 20 located on the path of the light propagating between the splitting means 16 and the first reflection means 17 and which serves to delay said light, with respect to the light propagating between the splitting means 16 and the second reflection means 18.
Each of the said first and second reflection means 17, 18 e.g. comprises a plane mirror oriented so as to receive, under normal incidence, the light reaching it from the splitting means 16, but is preferably realised with the aid of a catadioptric system, such as a transparent cube wedge. (The term cube wedge is understood to mean a tetrahedron, whose three faces are isosceles rectangular triangles, said wedge being oriented in such a way that the light reaching it from the splitting means 6 falls on its fourth face).
The first reflection means 17 is placed in a tank 21 filled with a liquid 22 and displaceable in translation parallel to the path of the light falling on it from the splitting means 16. The medium with parallel faces 20 is thus formed by the thickness of liquid 22 between the first reflection means 17 and the surface of the liquid facing the splitting means 16. This liquid surface is made flat by sealing tank 21 with the aid of a transparent plate 23 in contact with the liquid, which has the same optical index as the latter and which is perpendicular to the path of the light falling on the first reflection means 17. The mobility of the first reflection means within the liquid is ensured by displacement means 24, e.g. of the magnetic type and which will be described with reference to FIGS. 3 and 4.
The second reflection means 18 is also displaceable in translation parallel to the path of the light falling on it and coming from the splitting means 16. The translation of the second reflection means 18 is brought about with the aid of other displacement means 25 incorporating a support 26 to which the second reflection means 18 is fixed and which is displaceable in an e.g. dovetail slide 27.
The first reflection means 17 is regulated in such a way as to obtain the desired sensitivity for the interferometer according to the invention, bearing in mind relation (1) in which the variable L in this case assumes the value L 1 (thickness of the liquid between the first reflection means 17 and the liquid surface facing the splitting means 16, plus the thickness of plate 23) and the second reflection means 18 is then displaced in such a way that the distance thereof from the splitting means 16 is equal to the distance of the latter at the apparent position 28, viewed from the detection means 19, from the first reflection means 17.
A change in the sensitivity leads to a resetting of the position of reflection means 17 and 18 and also the orientation thereof when they are mirrors. The interest of using a catadioptric system in place of mirrors is that they are not sensitive to rotations (obviously of sufficiently small amplitudes), which obviates the need for said orientation resetting.
For example, the liquid used is xylene, whose optical index is equal to 1.48 and the laser is e.g. an ionized argon laser, whose emitted light is filtered to obtain a monofrequency radiation of wavelength 0.488 μm. Preferably, the power of the laser is chosen in such a way that the light flux traversing the liquid is at the most equal to 50 mW/cm 2 in order to obtain a stable transverse configuration of the field of interference fringes. Moreover, in order to further reduce the transverse temperature gradients in the liquid, i.e. perpendicular to the light propagation therein, the tank 21 is positioned vertically and the various components of the interferometer according to the invention are appropriately arranged in such a way that the first reflection means 17 receives, under a vertical incidence, the light from the splitting means 16.
FIGS. 3 and 4 diagrammatically show respectively in transverse and longitudinal sections, the means 24 for displacing the first reflection means 17. Tank 21 is in the form of a tube made from a non-magnetic material such as aluminium and which is closed in its lower part, which is mounted on a base 29. The said displacement means 24 are of the magnetic type and essentially comprise a support 30 mobile in tube 21 and provided with permanent magnets 31 and to which is fixed the first reflection means 17, together with a carriage 32 movable outside tube 21, positioned facing support 30 and also provided with permanent magnets 33 facing magnets 31, in such a way that the displacement of carriage 32 brings about the displacement of support 30.
According to a preferred embodiment, tube 21 is provided with external longitudinal blades 34. The carriage 32 is provided with slots 35 enabling it to slide on the blades 34, a locking screw 36 for immobilizing it at a given level of tube 21 and a pointer 37 for indicating said level, whereby a graduated scale member 38 can then be longitudinally fixed to tube 21, in such a way that the pointer moves along said scale. The carriage has ends which are diametrically opposed with respect to tube 21. The magnets 33 are U-shaped magnets of the same length and are distributed into two groups, each group comprising two elongated U-shaped magnets, which are juxtaposed and parallel to the tube axis Z on a magnet holder 39, which is itself fixed to one of the ends of carriage 32 with the aid of a screw 40. The ends of the U-shaped magnets are bent and turned towards tube 21. Support 30 slides in tube 21 and has external flats 41 permitting the passage of liquid 22 between support 30 and tube 21. Support 30 is made from a non-magnetic material and is able to reduce friction against the tube, polytetrafluoroethylene being an example of such a material. The magnets 31 of support 30 are rod magnets of the same length and parallel to the axis Z of the tube, each of them being held in said support and are magnetically coupled to one of the U-shaped magnets (the north and south poles of one respectively facing the south and north poles of the other).
For example, the magnets 31 are arranged in recesses 42 made in support 30. It is possible to provide recesses 42 parallel to axis Z issuing at the bottom of support 30 and to close them at the bottom with the aid of plugs 43 made from the same material as support 30 and enabling the magnets 31 to be held in these recesses 42.
When tank 21 is vertical, the support 30 can have a cavity 44 issuing into the bottom of support 30 and which is closed at the bottom by a sealing plug 45, permitting a possible introduction of liquid into cavity 44, so as to give support 30 a zero buoyancy.
FIG. 5 diagrammatically shows another embodiment of the interferometer according to the invention. The only difference between this embodiment and that described with reference to FIG. 2 is that it also comprises a first light reflector 46 and a second light reflector 47 consisting e.g. of plane mirrors. The first mirror 46 is located at the top of tank 21 parallel to the first catadioptric system 17 and in such a way that the light from the splitting means 16 and which reflects on the first catadioptric system 17 reaches the first mirror 46, is reflected on the latter and returns to the splitting means 16 following the same path in the opposite direction.
The second mirror 47 is arranged parallel to the second catadioptric system 18 and in such a way that the light from the splitting means 16 and reflecting on the second catadioptric system 18 reaches the second mirror 47, is reflected on the latter and returns to the splitting means 16 following the same path in the opposite direction.
The splitting means 16 is, for example, a splitter cube 16a. The interferometer according to the invention can then be constructed in such a way that its arms 16, 17 and 16, 18 are perpendicular, the cube 16a being in contact by an appropriate face with half of plate 23, the first mirror 46 being in contact with the other half of plate 23 and the first catadioptric system having an adequate size to face both the cube 16a and the first mirror 46. The second mirror 47 is then contiguous and parallel with another face of cube 16a, which corresponds to the second catadioptric system 18, which has an adequate size to face both cube 16a and the second mirror 47.
For example, the first mirror 46 can be obtained by depositing a reflecting coating on the other half of plate 23.
The interferometer of FIG. 5 makes it possible to cover a wide sensitivity range by displacing catadioptric system 17, 18 without touching mirrors 46, 47, the path of the light in the liquid being equal to 2L 2 , in which L 2 represents the thickness 20 of the liquid. With a liquid such as xylene of optical index 1.48, a useful length L 2 of 76 cm and the 0.488 μm line of an ionized argon laser, it is possible to measure velocity variations exceeding 30 m/s.
Obviously, as in the case of the interferometer described with reference to FIG. 2, the second catadioptric system 18 is still regulated in such a way that the distance between it and the splitting means 16 is equal to the distance between the latter and the apparent position, viewed from detection means 19 of the first catadioptric system 17.
The detection means 19 (FIGS. 2 and 5) can comprise a cinematographic recorder 48 for filming the time evolution of the field of interference fringes formed in the interferometer, which makes it possible to determine, as a function of time t, the velocity V(t) of the surface 14 with its sign changes, without introducing any error due to variations of the light intensity back scattered by surface 14.
This result can also be obtained with the aid of two photoelectric detectors, by recording therewith two phase-displaced signals, e.g. in phase quadrature, and by optionally measuring the light intensity back scattered by surface 14. For this purpose, the detection means 19 comprise two optical fibres 49, 50 (e.g. of silica and of diameter 1 mm), which are arranged in such a way that two respective ends of these fibres observe the light interferences formed in the interferometer at two points in phase quadrature. This is shown in FIG. 6, where it is possible to see an enlargement of the field of interference fringes. The end of fibre 49 is centered on a bright fringe, whilst the end of fibre 50 is at the limit of a bright fringe and a dark fringe. These fibres are also respectively connected by their other ends to two photodiodes 51, 52, which are themselves respectively connected to the inputs X and Y of an oscilloscope 53 working in the scanning mode XY. It is possible to see on the oscilloscope screen, signals I X and I Y corresponding to the light trapped by the fibres and the angle between the mirrors 46, 47 is regulated until these signals are in phase quadrature (an ellipse appearing in this case on the oscilloscope screen). This is followed by passing from scanning mode XY to mode X(t) and Y(t).
There is also a check of the light intensity I 0 back scattered by surface 14 when said intensity fluctuates (which is generally the case), with the aid of semi-transparent mirrors 54 which sample part thereof and a photodetector 55 which traps said part.
Obviously, instead of placing the liquid medium with parallel faces between the first reflection means and the splitting means, as is the case in FIGS. 2 and 5, it can be placed between the second reflection means and the splitting means, the second reflection means then being placed in the tank and the displacement means 24 and 25 are then switched over (and by regulating the first reflection means in such a way that its distance from the splitting means is equal to the distance between the latter and the apparent position, viewed from the detection means from the second reflection means).
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A velocity interferometer has a continuously variable sensitivity and is particularly applicable to the study of the movement of reflecting polished surfaces or back-scattered rough surfaces. The interferometer is a Michelson interferometer with a widened field comprising in a per se known manner a light splitter and two light reflectors, one of which is associated with a medium having parallel faces. The medium is constituted by a fluid in which the associated reflector is immersed and displaceable in translation parallel to the path of the light falling on it, the other reflector also being displaceable in translation parallel to the path of the light falling thereon.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 09/348,555, filed Jul. 7, 1999, now U.S. Pat. No. 6,169,695, which is a divisional of U.S. patent application Ser. No. 08/808,392, filed Feb. 28, 1997, issued on Nov. 23, 1999 as U.S. Pat. No. 5,991,904.
TECHNICAL FIELD
The present invention relates generally to the testing of memory integrated circuits (IC), and, more specifically, to a method and apparatus for reducing the test time of memory cells in a dynamic random access memory (DRAM).
BACKGROUND OF THE INVENTION
During the manufacture of dynamic random access memories (“DRAMs”), it is necessary to test the DRAM to assure that it is operating properly. Electronic systems containing DRAMs, such as computers, normally test the DRAMs when power is initially applied to the system. A DRAM is typically arranged as an array of individual memory cells. In order to assure that each memory cell is operating properly, prior art test methods write data having a first binary value (e.g., a 1) to all memory cells in the memory array. For a memory array having n rows and m columns of memory cells, it requires n×m bus cycles to write the first binary data values to all the memory cells in the memory array. A bus cycle is the period of time it takes to write or read data to or from an individual memory cell in the DRAM. After having written the first binary data values to the memory cells, this data must be read from the memory cells to assure that each memory cell is operating properly. Once again, this requires n×m bus cycles to read the data having a first binary value. Data having a second binary value (e.g., a 0) is next written to each memory cell in the memory array and is then read from each memory cell to assure each memory cell is operating properly. Each of these read and write operations also requires n×m bus cycles to complete. Therefore, to test each memory cell in the memory array, a total of four times n×m bus cycles is required. In the case of a 16 megabit×4 DRAM, 67,108,864 bus cycles are required to perform a complete test of every memory cell.
To reduce the number of cycles required to test a memory array, various prior art row copy circuits have been developed which simultaneously write data to multiple memory cells. A typical prior art row copy circuit includes a memory array with multiple row access lines, multiple paired digit lines which intersect the row access lines, and a plurality of memory cells coupled at the intersections to form rows of memory cells. The row access lines provide access to associated rows of memory cells and the paired digit lines carry data to and from the accessed memory cells. A sense amplifier is coupled to each pair of digit lines for sensing the data stored by an accessed memory cell and providing that data on the digit lines. The sense amplifier provides the data on the digit lines until an equilibrate control erases the data on the multiple paired digit lines.
The row copy circuit further includes an on-chip circuit that copies data carried by the paired digit lines and stored in a first row of memory cells to at least one other row of memory cells by suspending operation of the equilibrate control to prevent erasure of the data on the paired digit lines. The row copy circuit accesses a first row of memory cells so that the sense amplifiers store the data placed on the digit lines by the accessed first row of memory cells. The row copy circuit then accesses subsequent rows of memory cells to copy the data provided by the sense amplifiers on the digit lines into the other rows of memory cells in the memory array. This circuit thus allows a test pattern of data to be more quickly written to the memory cells of the memory array via the row copy operation. The data written to the memory cells through the row copy operation must be read from the memory cells through a standard read cycle to verify that each memory cell is operating properly.
As will be appreciated by one skilled in the art, the greater the number of bus cycles required to test the memory cells in a DRAM the greater the time and the cost of testing the DRAM. Thus, it is desirable to develop a test system which reduces the number of bus cycles required to test the memory cells of a DRAM.
SUMMARY OF THE INVENTION
A circuit transfers data in an array of memory cells arranged in rows and columns. In one embodiment, the circuit comprises a plurality of row lines, a plurality of pairs of complementary digit lines, and an array of memory cells, each memory cell having a control terminal coupled to one of the row lines and a data terminal coupled to one of the complementary digit lines of one of the pairs of complementary digit lines responsive to a row enable signal on the row line of the row corresponding to the memory cell. A plurality of sense amplifiers are included in the circuit, each sense amplifier coupled to an associated pair of first and second complementary digit lines which senses a voltage differential between the first and second complementary digit lines and, in response to the sensed voltage differential, drives the first and second complementary digit lines to voltage levels corresponding to complementary logic states. A plurality of equilibration circuits are also included in the circuit, each equilibration circuit coupled between one of the pairs of complementary digit lines and operable to equalize the voltage level on each pair of complementary digit lines to a predetermined level responsive to an equilibration signal. A control circuit is coupled to the plurality of row lines and the equilibration circuits. The control circuit is operable to: write a pattern of data to an initial row of the memory array; generate the equilibrate signal; apply a row enable signal to the row line of the memory cells in the initial row; terminate the row enable signal for the initial row; apply a row enable signal to the row line to which the memory cells in another row are connected; terminate the row enable signal for the another row; and generate the equilibrate signal.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a memory-cell array of a DRAM including a test control circuit in accordance with one embodiment of the present invention.
FIG. 2 is a flowchart of the process executed by the test control circuit of FIG. 1 .
FIG. 3 is a block diagram of a DRAM that includes the memory-cell array and test control circuit of FIG. 1 .
FIG. 4 is a block diagram of a computer system that includes the DRAM of FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic block diagram of a DRAM 10 having a memory-cell array 12 which includes a test control circuit 11 in accordance with one embodiment of the present invention. The memory-cell array 12 includes a number of memory cells 14 arranged in rows and columns. Each memory cell 14 includes an access switch in the form of a transistor 16 and a storage element in the form of a capacitor 18 . The capacitor 18 includes a first plate 20 coupled to a reference potential, which is typically equal to approximately Vcc/2. A second plate 22 of the capacitor 18 is coupled to the drain of the transistor 16 . Each of the memory cells 14 stores a single bit of binary data. The binary data is stored in the memory cells 14 as a voltage across the capacitor 18 . A voltage of approximately Vcc at the plate 22 of the capacitor 18 corresponds to a first binary data value, which is typically a 1. Conversely, a voltage of approximately 0 at the plate 22 corresponds to a second binary data value, typically a 0.
The memory cells 14 are arranged in n rows and m columns. One memory cell 14 is positioned at the intersection of each row and column. Every row of memory cells 14 has an associated row line ROW and every column of memory cells has an associated pair of complementary digit lines DIGIT and {overscore (DIGIT)}. Each memory cell 14 in a given row of memory cells has a control terminal in the form of the gate of the transistor 16 coupled to the associated row line ROW. Each memory cell 14 in a given column of memory cells has a data terminal in the form of the source terminal of the transistor 16 coupled to one of the associated complementary digit lines DIGIT and {overscore (DIGIT)}. Although the memory-cell array 12 is described as including complementary digit lines DIGIT and {overscore (DIGIT)}, one skilled in the art will appreciate that the present invention is applicable to other memory structures and not limited to this specific memory structure.
The memory-cell array 12 includes an equilibration circuit 46 coupled between each pair of complementary digit lines DIGIT and {overscore (DIGIT)} which operates to equalize the voltage on the associated pair of complementary digit lines. Each equilibration circuit 46 comprises an equilibration transistor 48 and a precharge circuit 50 . The equilibration transistor 48 has its drain and source terminals coupled between the complementary digit lines DIGIT and {overscore (DIGIT)} and its gate terminal coupled to an equilibration line EQ. The precharge circuit 50 includes a pair of transistors 52 and 54 with the drain terminals of these transistors connected to the complementary digit lines DIGIT and {overscore (DIGIT)}, respectively. The source terminals of the transistors 52 and 54 are connected to a reference voltage approximately equal to Vcc/2, and the gates of the transistors are coupled to the equilibration line EQ.
In operation, the equilibration circuit 46 equalizes the voltage on the complementary digit lines DIGIT and {overscore (DIGIT)} to the same voltage of approximately Vcc/2. To activate the equilibration circuit 46 , the equilibration line EQ is driven with a voltage approximately equal to Vcc. In response to this voltage on the equilibration line EQ, the transistors 48 , 52 and 54 all are turned ON. The transistors 52 and 54 of the precharge circuit 50 drive the complementary digit lines DIGIT and {overscore (DIGIT)} to voltage levels approximately equal to Vcc/2, and the equilibration transistor 48 assures that both the complementary digit lines are at the same voltage level. After the complementary digit lines DIGIT and {overscore (DIGIT)} are equilibrated to approximately Vcc/2, the equilibration line EQ is driven to approximately 0 volts to turn OFF the transistors 48 , 52 and 54 .
The memory-cell array 12 further includes an isolation circuit 56 coupled to each pair of complementary digit lines DIGIT and {overscore (DIGIT)}. In the embodiment of FIG. 1, each isolation circuit 56 comprises a pair of isolation transistors 58 and 60 . The gate terminals of the isolation transistors 58 and 60 are coupled to an isolation line ISO. In operation, the isolation circuits 56 couple a pair of complementary digit lines DIGIT and {overscore (DIGIT)} of the memory array to pairs of complementary digit lines 62 and 64 , respectively, of associated sense amplifiers 66 when the isolation line ISO is driven with a voltage approximately equal to Vcc to turn ON the isolation transistors 58 and 60 .
In the embodiment of FIG. 1, each sense amplifier 66 includes four transistors 68 , 70 , 72 and 74 connected as shown. The transistors 68 and 70 operate to couple a voltage of approximately zero volts to the digit lines 62 and 64 , respectively. Operation of the transistors 68 and 70 is complementary such that when transistor 68 is ON, transistor 70 is OFF, and vice versa. The transistors 72 and 74 operate in the same complementary way to couple a voltage of Vcc to the digit lines 62 and 64 , respectively. It should be noted that while the transistors 68 and 70 are shown as been connected directly to ground and transistors 72 and 74 as being connected directly to Vcc, such direct connections are merely for ease of explanation. Typically, a control circuit (not shown) couples the transistors to their respective voltage only when the sense amplifier 66 is to store data from an accessed memory cell 14 and otherwise decouples the transistors from their respective voltages.
Each sense amplifier 66 operates to sense a voltage differential between the complementary digit lines 62 and 64 and, in response to this sensed voltage differential, to drive the complementary digit lines 62 and 64 to voltage levels which correspond to complementary logic states. In other words, the sense amplifiers 66 sense a voltage differential between the complementary digit lines 62 and 64 and drive the complementary digit line having the higher voltage to Vcc and the other complementary digit line to approximately zero volts.
Operation of the sense amplifiers 66 is best understood by way of example. Assume that an equilibration interval has just occurred so that the voltage level on the complementary digit lines is equal to approximately Vcc/2. Further assume that the memory cells 14 coupled to the row line ROW 0 contain data corresponding to a binary 1, which typically means that the voltage at plates 22 of the capacitors 18 is approximately equal to zero volts, i.e., the complement of Vcc representing a logic 1. When the row line ROW 0 is activated (driven to approximately Vcc), the voltage level at the plates 22 of the capacitors 18 is transferred to the complementary digit lines {overscore (DIGIT)} which results in the complementary digit lines {overscore (DIGIT)} being lowered to a voltage level which is now less than Vcc/2. When the isolation line ISO is activated, the complementary digit lines DIGIT and {overscore (DIGIT)} of the array are coupled to the complementary digit lines 62 and 64 , respectively, of the sense amplifiers 66 . In this instance, the complementary digit lines 62 are at approximately Vcc/2 while the complementary digit lines 64 are lowered to the voltage level less than Vcc/2.
As a result of the complementary digit lines 64 being at a lower voltage level than the complementary digit lines 62 , the transistors 68 and 74 are driven OFF while the transistors 70 and 72 are driven ON. When the transistors 68 and 74 are driven all the way OFF, the complementary digit lines 62 are at approximately Vcc and the complementary digit lines 64 are at approximately zero volts. Thus, the voltage level of the digit lines DIGIT corresponds to the binary 1 and the voltage level of the complementary digit lines {overscore (DIGIT)} corresponds to the binary 0 voltage stored in the addressed memory cells 14 . The data stored in each sense amplifier 66 is provided on a pair of output terminals 76 to read/write circuitry (not shown in FIG. 1 ).
In normal operation of the DRAM 10 , before data is read from the memory cells 14 , control circuitry (not shown in FIG. 1) executes an equilibration interval. During the equilibration interval, the control circuitry drives each of the row lines ROW with a voltage approximately equal to zero volts, thereby deactivating each of the memory cells 14 . The isolation line ISO is also driven high, thereby turning ON the isolation transistors 58 , 60 to couple the complementary digit lines of sense amplifiers 66 to the associated complementary digit lines DIGIT and {overscore (DIGIT)} of the array. The equilibration line EQ is then driven by the control circuitry to turn ON the equilibration circuits 46 and equalize the voltage on each complementary digit line DIGIT and {overscore (DIGIT)} to approximately Vcc/2. Alternatively, the isolation transistors 26 and 28 can be turned OFF, and the digit lines 62 , 64 can be equilibrated by circuitry in the sense amplifier 66 (not shown). Such equilibration of the sense amplifiers 66 is conventional and therefore not described in more detail.
After the equilibration interval, the control circuitry drives the row line ROW of the addressed memory cell 14 with a voltage approximately equal to Vcc to activate each memory cell coupled to the activated row line. The transistor 16 in each activated memory cell 14 is turned ON by Vcc applied to its gate, thereby transferring the voltage at the plate 22 of the capacitor 18 to the complementary digit line DIGIT or {overscore (DIGIT)} coupled to the activated memory cell. For example, if the row line ROW 0 is activated, the voltage on the plate 22 of the capacitor 18 in each memory cell 14 in the row is transferred to the complementary digit line {overscore (DIGIT)} associated with that cell. The sense amplifiers 66 then compare the voltage on the complementary digit line {overscore (DIGIT)} coupled to the activated memory cell 14 to the voltage of Vcc/2 on the other complementary digit line. In response to the sensed voltage differential between the complementary digit lines DIGIT and {overscore (DIGIT)}, each sense amplifier 66 drives the higher complementary digit line to Vcc and drives the lower complementary digit line to approximately zero volts. The voltage level on the complementary digit lines coupled to the activated memory cells 14 now represents the binary value of the data stored in the activated memory cells. The data contents of the addressed memory cell 14 is then read from the sense amplifier 66 coupled to the column of the addressed memory cell by read/write circuitry (not shown in FIG. 1 ).
A write operation is substantially different from a read operation because equilibration is not required in a write operation. Instead, complementary data is coupled through read/write data path circuitry (not shown) to respective write driver transistors (not shown) which apply the complementary data to the respective complementary digit lines DIGIT and {overscore (DIGIT)}. During this time, one of the row lines ROW is driven high, thereby coupling the voltage on one of the complementary digit lines DIGIT or {overscore (DIGIT)} to the capacitor 22 in the memory cell 14 located at the intersection of the addressed row and column.
As seen from the description of a conventional read cycle, data from all memory cells 14 in a row which is activated is transferred into the sense amplifiers 66 . If the transferred data in all the sense amplifiers 66 could be utilized, one skilled in the art will appreciate that the amount of time required to test each memory cell 14 in the memory-cell array 12 could be reduced. The present invention reduces the test time of a DRAM by utilizing the transferred data stored in all the sense amplifiers 66 to perform transfers of binary data to the memory cells 14 in the array 12 .
The memory-cell array 12 is tested under control of the test control circuit 11 . The test control circuit 11 operates to provide signals on the isolation line ISO, the equilibration line EQ, and controls the activation of all the row lines ROW during testing of the memory-cell array 12 . To test the memory-cell array 12 , the test control circuit 11 first writes a predetermined test pattern of data to the memory cells 14 coupled to the row line ROW 0 . This test pattern of data is written to the memory cells 14 coupled to the row line ROW 0 during standard write cycles as previously described. The test pattern of data written to the memory cells 14 may be varied. For example, either a binary 1 or a binary 0 could be written to and stored in each memory cell 14 . Alternatively, an alternating bit pattern could be written to the memory cells 14 so that the cells alternately store binary 1s and 0s (e.g., 1010. . . ).
After the test control circuit 11 has written and stored the predetermined test pattern of data in the memory cells 14 coupled to the row line ROW 0 , the test control circuit performs an equilibrate cycle to equilibrate the complementary digits lines DIGIT and {overscore (DIGIT)} in the memory-cell array 12 and the complementary digit lines 62 and 64 in the sense amplifiers 66 . Once the equilibration cycle has been completed, the test control circuit 11 activates the row line ROW 0 to provide the data stored in each of the memory cells 14 on the associated pair of complementary digit lines DIGIT and {overscore (DIGIT)}. The sense amplifiers 66 store the data provided by the accessed memory cells 14 coupled to the row line ROW 0 . After the sense amplifiers 66 have stored the data, the test control circuit 11 deactivates the row line ROW 0 . At this point, the sense amplifiers 66 retain the stored data and continue to provide this data on the complementary digit lines DIGIT and {overscore (DIGIT)}. The test control circuit 11 next activates the row line ROW 1 to transfer the data provided by each sense amplifier 66 into the associated memory cells 14 coupled to the row line ROW 1 . The test control circuit 11 thereafter deactivates the row line ROW 1 to isolate the memory cells 14 coupled to the row line ROW 1 with each memory cell having stored the associated bit of data.
At this point, the test control circuit 11 has controlled the memory-cell array 12 so that the test pattern data stored in the first row has been copied to the second row. The test control circuit 11 next performs an equilibrate cycle by activating the equilibrate line EQ to equilibrate the complementary digit lines DIGIT and {overscore (DIGIT)} in the array 12 and the complementary digit lines 62 and 64 of the sense amplifiers 66 . Once the memory-cell array 12 has been equilibrated, the test control circuit 11 activates the row line ROW 1 to store the data stored in the memory cells 14 coupled to the row line ROW 1 in the sense amplifiers 66 . The test control circuit 11 repeatedly performs these steps until the test pattern data initially written into the first row of the memory-cell array 12 has been copied into row n-1 of the memory-cell array. Once the test pattern data has been copied to row n-1, the test control circuit 11 performs a standard read operation on each memory cell 14 coupled to the row line ROW n-1 and compares the data read from this row with the data initially written to the first row of the memory-cell array 12 .
If each memory cell 14 in the memory-cell array 12 is operating properly, the data read by the test control circuit 11 from row n-1 will be the same as that initially written to the first row. A defective memory cell 14 , however, will result in the data read from row n-1 of the memory-cell array 12 being different from that initially written to the first row of the memory-cell array. At this point, the test control circuit 11 may execute a search routine in order to isolate the specific memory cell 14 which is defective. Such a search routine may be, for example, a binary search as known in the art or any other search methodology which may be used to isolate a defective memory cell.
In a typical binary search, the test control circuit 11 would first read data from a row midway through the memory-cell array 12 . For example, if there were a thousand row lines in the memory-cell array 12 , the test control circuit 11 would perform a standard read of each of the memory cells in row 500 and compare the data read from row 500 to the data initially written to row 0 . If the data read from row 500 does not equal that written to row 0 , the faulty memory cell 14 lies somewhere between row 0 and row 500 . If the data read from row 500 is equal to the data initially written to row 0 , the test control circuit 11 knows the defective memory cell 14 is located somewhere between row 501 and row 1000 . The test control circuit 11 then selects the group containing the defective memory cell 14 and reads data from a row midway between the two rows defining the group containing the defective memory cell. Depending on whether the data read from this midway row is the same as or different from the data initially written, the control circuit 11 once again selects the group of rows containing the defective memory cell 14 . The test control circuit 11 continues this process until it ultimately identifies the row containing the defective memory cell 14 . Once the row containing the defective memory cell 14 has been identified, the test control circuit 11 determines the column containing the defective memory cell by simply identifying the cell which contains different binary data than was originally written to that cell.
By identifying defective memory cells 14 in this manner, the test control circuit 11 is able to test the entire memory-cell array 12 faster than prior art systems. The test pattern data need only be written to the first row in the memory-cell array 12 and read from the last row. In contrast, with prior art row copy systems, after the test data pattern is stored all in the memory cells 14 through the row copy operations, this data still has to be read from each memory cell to assure proper operation of the cells. There is no need to do this with the present system because the test pattern of data is propagated through each row of memory cells 14 and not merely written from the sense amplifiers into each row of cells as with a standard row copy system. Thus, each row of memory cells 14 has the test pattern of data both written to it and read from it to comprehensively test the operation of each memory cell.
FIG. 2 is a flowchart showing one embodiment of a test process executed by the test control circuit 11 for testing each memory cell 14 in the memory-cell array 12 . The process starts in step 100 and proceeds immediately to step 102 . In step 102 , the test control circuit 11 sets an index N equal to 0. The index N corresponds to the row of memory cells 14 in the memory-cell array 12 that is currently being accessed under control of the test control circuit 11 . From step 102 the process proceeds to step 104 .
The first cycle through the process executed by the test control circuit 11 , the index N equals 0 in step 104 . In this case, the test control circuit 11 writes the test pattern data to the memory cells 14 coupled to the row line ROW 0 . From step 104 , the process proceeds to step 106 and the test control circuit 11 performs an equilibrate cycle on the memory-cell array 12 . After the memory-cell array 12 has been equilibrated, the process proceeds to step 108 . In step 108 , the test control circuit 11 activates the row line ROW 0 thereby causing the sense amplifiers 66 for the respective columns to store the data in ROW 0 of the array. From step 108 , the process proceeds to step 114 where the test control circuit 11 deactivates the row line ROW 0 . From step 114 , the process goes to step 116 .
In step 116 , the test control circuit 11 activates the row line ROW 1 thereby transferring into ROW 1 the data previously transferred from ROW 0 . The process then goes to step 120 where the test control circuit 11 deactivates the row line ROW 1 to store the test pattern data in the memory cells 14 coupled to the row line ROW 1 . The process proceeds from step 120 to step 124 . In step 124 , the test control circuit 11 determines whether the index N equals n-1, where n is equal to the number of rows in the memory-cell array 12 . If the determination in step 124 is negative, the process proceeds to step 126 and the test control circuit 11 sets the index N equal to N+1. From step 126 , the process then proceeds back to step 106 and the test control circuit 11 once again executes steps 106 through step 124 .
Until the determination in step 124 is positive, the test control circuit 11 continues to execute steps 106 through step 124 . As a result, the test pattern data initially written to the memory cells 14 coupled to the row line ROW 0 is propagated through the other rows of the memory-cell array 12 . When the determination in step 124 is positive, this means that the test control circuit 11 has copied the test pattern data into the memory cells 14 coupled to the last row line ROW n-1 . Once the determination in step 124 is positive, the process proceeds to step 128 .
In step 128 , the test control circuit 11 performs an equilibrate cycle on the memory-cell array 12 . After this equilibration cycle, the process proceeds to step 130 and the test control circuit 11 performs standard read cycles to read the test pattern data from the memory cells 14 coupled to the last row line ROW n-1 of the memory-cell array 12 . After step 130 , the process goes to step 132 . In step 132 , the test control circuit 11 compares the test pattern data initially written to the memory cells 14 coupled to the row line ROW 0 to the test pattern data read from the memory cells coupled to the last row line ROW n-1 and determines if the data in the two rows is equal. If the determination in step 132 is positive, the process proceeds immediately to step 134 and the test mode executed by the test control circuit 11 is complete, meaning that every memory cell 14 in the memory-cell array 12 is operating properly.
When the determination in step 132 is negative, however, the process proceeds to step 136 . In step 136 , the test control circuit 11 executes a search subroutine to precisely identify the defective memory cell 14 . As previously described, such a search subroutine may be, for example, a binary search as known in the art.
In an alternative embodiment of the process executed by the test control circuit 11 , the test control circuit writes a first test pattern of data to the memory cells 14 coupled to the row line ROW 0 and a second test pattern of data to the memory cells coupled to the row line ROW 1 . For example, the first test pattern of data may be an alternating bit pattern 101010 . . . with the initial binary 1 being written to the memory cell 14 associated with the complementary digit lines DIGIT 0 and {overscore (DIGIT)} 0 . The second test pattern of data would then typically be the alternating bit pattern 010101 . . . with the initial binary 0 being written to the memory cell 14 associated with the complementary digit lines DIGIT 0 and {overscore (DIGIT)} 0 . In this way, a checkerboard pattern is formed and adjacent memory cells 14 store complementary binary data. Other test bit patterns may, of course, be used in this embodiment.
With this alternative embodiment, the test control circuit 11 executes a process similar to that shown in FIG. 4 to alternately copy the first test pattern data to the next adjacent even row in the memory-cell array 12 and then copy the second test pattern data to the next adjacent odd row in the memory-cell array. As before, the test control circuit 11 propagates the first and second test patterns of data through the memory-cell array 12 until the first test pattern of data is stored in the last even row of the memory-cell array and the second test pattern of data is stored in the last odd row of the memory-cell array. At this point, the test control circuit 11 reads the first test pattern data from the last even row of the memory-cell array 12 and reads the second test pattern data from the last odd row of the memory-cell array. The test control circuit 11 compares the first test pattern data stored in the last even row with the first test pattern data written to the first row of memory cells 14 coupled to the row line ROW 0 . If the two test patterns of data are not equal, the test control circuit 11 performs a binary search on the even rows of the memory-cell array 12 to isolate the defective memory cell 14 . In the same way, the test control circuit 11 compares the second test pattern data stored in the last odd row with the second test pattern data written to the second row of memory cells 14 coupled to the row line ROW 1 . If these two test patterns of data are not equal, the test control circuit 11 performs a binary search on the odd rows of the memory-cell array to isolate the defective memory cell 14 .
FIG. 3 is a block diagram of a DRAM 10 including the memory-cell array 12 and test control circuit 11 of FIG. 1 . The test control circuit 11 is shown as coupled to the memory-cell array 12 for controlling the test mode of the memory-cell array as previously described. The memory device 10 further includes an address decoder 86 , control circuit 88 , and read/write circuitry 90 , all of which are conventional and known in the art. The address decorder 86 , control circuit 88 , and read/write circuitry 90 are all coupled to the memory-cell array 12 . In addition, the address decoder 86 is coupled to an address bus, the control circuit 88 is coupled to a control bus, and the read/write circuitry 90 is coupled to a data bus.
In operation, external circuitry provides address, control, and data signals on the respective busses to the memory device 10 . During a read cycle, the external circuitry provides a memory address on the address bus and control signals on the control bus to the memory device 10 . In response to the memory address on the address bus, the address decoder 86 provides a decoded memory address to the memory-cell array 12 while the control circuit 88 provides control signals to the memory-cell array 12 in response to the control signals on the control bus. The control signals from the control circuit 88 control the memory-cell array 12 so that the memory-cell array provides data to the read/write circuitry 90 . The read/write circuitry 90 then provides this data on the data bus for use by the external circuitry. During a write cycle, the external circuitry provides a memory address on the address bus, control signals on the control bus, and data on the data bus. Once again, the address decoder 86 decodes the memory address on the address bus and provides a decoded address to the memory-cell array 12 . The read/write circuitry 90 provides the data on the data bus to the memory-cell array 12 and this data is stored in the addressed memory cells in the memory-cell array under control of the control signals from the control circuit 88 .
FIG. 4 is a block diagram of a computer system 92 which uses the memory device 10 of FIG. 3 . The computer system 92 includes computer circuitry 94 for performing various computing functions, such as executing specific software to perform specific calculations or tasks. In addition, the computer system 92 includes one or more input devices 96 , such as a keyboard or a mouse, coupled to the computer circuitry 94 to allow an operator to interface with the computer system. Typically, the computer system 92 also includes one or more output devices 98 coupled to the computer circuitry 94 , such output devices typically being a printer or a video terminal. One or more data storage devices 99 are also typically coupled to the computer circuitry 94 to store data or retrieve data from external storage media (not shown). Examples of typical storage devices 99 include hard and floppy disks, tape cassettes, and compact disk read only memories (CD-ROMs). The computer circuitry 94 is typically coupled to the memory device 10 through a control bus, a data bus, and an address bus to provide for writing data to and reading data from the memory device.
It is to be understood that even though various embodiments and advantages of the present invention have been set forth in the foregoing description, the above disclosure is illustrative only, and changes may be made in detail, and yet remain within the broad principles of the invention. Therefore, the present invention is to be limited only by the appended claims.
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A circuit transfers data in an array of memory cells arranged in rows and columns. The circuit includes a plurality of row lines, a plurality of pairs of complementary digit lines, and an array of memory cells, each memory cell having a control terminal coupled to one of the row lines and a data terminal coupled to one of the complementary digit lines of one of the pairs of complementary digit lines responsive to a row enable signal on the row line of the row corresponding to the memory cell. A plurality of sense amplifiers are included in the circuit, each sense amplifier coupled to an associated pair of first and second complementary digit lines which senses a voltage differential between the first and second complementary digit lines and, in response to the sensed voltage differential, drives the first and second complementary digit lines to voltage levels corresponding to complementary logic states. A plurality of equilibration circuits are also included in the circuit, each equilibration circuit coupled between one of the pairs of complementary digit lines and operable to equalize the voltage level on each pair of complementary digit lines to a predetermined level responsive to an equilibration signal. A control circuit is coupled to the plurality of row lines and the equilibration circuits. The control circuit is operable to: write a pattern of data to an initial row of the memory array; generate the equilibrate signal; apply a row enable signal to the row line of the memory cells in the initial row; terminate the row enable signal for the initial row; apply a row enable signal to the row line to which the memory cells in another row are connected; terminate the row enable signal for the another row; and generate the equilibrate signal.
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BACKGROUND OF THE INVENTION
The present invention relates to data processing apparatus including a cordless keyboard used for office computers, personal computers and terminal equipment in banks.
In the office computers, personal computers and terminal equipment in banks, the devices are grouped depending upon their functions into keyboards for operation, CRT displays for monitoring, and control units for effecting electronic processing from the standpoint of improving operability and effectively utilizing the desk. On the desk are arranged the keyboard with which the operation can be carried out at all times and the CRT display, and the control unit that requires no operation is installed under or by the desk. Cables run among them hindering the operation, occupying space and impairing the appearance. Therefore, attempts have been made to eliminate the wires by using optical signals instead of using cables as disclosed in, for example, U.S. Pat. No. 4,313,227.
According to the conventional apparatus, however, reliability is not necessarily maintained sufficiently in transmitting the signals between the keyboard and the control unit without using cord. Furthermore, under the environment in which the office computers or terminal equipment in a bank are operated simultaneously such as in an office or at the windows of the bank, light affects one another among the apparatuses from which erroneous operation may result.
With the keyboard having no wire, furthermore, the circuitry in the keyboard must be operated by a power source such as cells. When used for business in offices and in banks, the keyboard must be operated for about eight hours a day, and the cells must be renewed or must be recharged almost everyday.
SUMMARY OF THE INVENTION
The object of the present invention is to solve such assignments inherent in the prior art and to provide a cordless keyboard which does not erroneously operate and which maintains high reliability in transmitting signals even when a plurality of apparatuses are simultaneously operated.
Another object of the present invention is to provide a cordless keyboard which does not require the cells to be renewed or electrically recharged, and which features improved operability.
The present invention is concerned with a cordless keyboard comprising means through which a keyboard transmits keycodes to a corresponding controller, means which receives keycodes that are sent back from the controller, and means which compares the transmitted keycodes with the received keycodes.
The present invention is further concerned with a cordless keyboard which is served with electric power via a high-frequency coil embedded in a desk on which the keyboard is placed and via a receiving coil in the keyboard.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating the constitution of a terminal controller in a bank using a cordless keyboard of the present invention;
FIG. 2 is a diagram which concretely illustrates the constitution of an encoder of FIG. 1;
FIG. 3, is a diagram showing signal blocks for the keycodes;
FIG. 4 is a time chart of signal waveforms of the encoder of FIG. 1;
FIG. 5 is a time chart for determining whether the data is correct or incorrect;
FIG. 6 is a diagram which concretely illustrates the constitution of a decoder of FIG. 1;
FIG. 7 is a diagram which illustrates in detail the constitution of a comparator and a data comparator of FIG. 6; and
FIG. 8 is a diagram illustrating voltages input to the comparator of FIG. 7.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the invention will now be described in detail in conjunction with the drawings.
FIG. 1 is a diagram illustrating the constitution of a terminal controller in a bank using a wireless keyboard according to an embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a display, 2 denotes a controller, 3 denotes a keyboard module, and 4 denotes a desk on which the keyboard 3 is placed. The display 1 and the controller 2 are connected together as one module through an interface cable. Data are exchanged between the keyboard 3 and the display 1 in the form of light signals using light-emitting elements 14, 31 and light-receiving elements 13, 32. When a given key is depressed in a key switch 37, a keycode corresponding to the key is formed by a keycode generator 38. The keycode is stored in a keycode buffer 35 and to which is attached a uniquely specific device code of the keyboard by an encoder 33. After being modulated with a frequency specific to the keyboard, the encoded keycode is converted into radiation, such as a light signal through an electro-photo converter 31. The light signal is converted from received radiation into an electric signal through a photo-electric converter 13. The device code of the keyboard 3 is picked up by the decoder 11 and is sent to the controller 2 via a cable. The controller 2 determines whether a parent-child relationship is established or not relative to the controller 2. The device code that has the parent-child relationship is the one by which the device that has received the signal can be recognized.
When the keyboard has the parent-child relationship as determined by the controller, the keycode is received by the controller 2, a uniquely specific device code is attached thereto by an encoder 12 that is similar to the encoder 33, and the keycode is modulated with a frequency specific to the controller 2 and is returned as an encoded keycode back to the keyboard 3 via an electro-photo converter 14 and a photo-electric converter 32. As for the encoded keycode that is returned back, the controller device code sent from the controller 2 is picked up by the decoder 34 that is similar to the decoder 11 for the keyboard to determine whether they establish a parent-child relationship or not. When the parent-child relationship is established by the keyboard, a comparator 36 compares the keycode that is returned back with the keycode stored in the keycode buffer 35. When the output of the comparator 36 indicates the coincidence, the input of the key depressed in the next time is processed. The key input of the next time is transmitted after a predetermined period of time T 1 has passed. When the output of the comparator 36 indicates the noncoincidence, the keycode stored in the key buffer 35 is transmitted to the controller 2 according to the algorithm that is the same as the one mentioned above within the predetermined period of time T 1 The controller 2 sends back again the keycode that is returned back, and monitors the signal from the keyboard 3 for the predetermined period of time T 1 When there is no signal from the keyboard for the period of time T 1 after the returned keycode had been sent, the keycode received at first is treated as true data. Further, when the controller 2 has received the keycode from the keyboard 3 that has the parent-child relationship within the period of time T 1 , the keycode that was received previously is determined to be an incorrect keycode. The keycode received within the time T 1 is regarded to be the one that is received first, and the above-mentioned keycode is returned back to the keyboard 3. The above-mentioned operation is carried out repetitively.
The controller 2 may return back its specific device code received from the keyboard 3. Alternatively a different specific device code may be returned back. In the latter case, erroneous operation is prevented from taking place that may be caused upon receipt of a reflected wave signal of the signal sent from the keyboard 3.
Within the time T 1 , the controller 2 recognizes only those series of signals having the same device code as the device code attached to the keycode received previously, as the keyboard 3 having a parent-child relationship.
FIG. 5 is a time chart illustrating the operation for comparing the keyboard data.
FIG. 5(a) shows a signal with which the controller 2 sends the keycode for confirmation back to the keyboard 3, and FIG.5(b) shows a signal sent again by the keyboard 3 or noise. In the foregoing description, when the device codes picked up from the data received by the controller 2 or the keyboard 3 are determined to establish no parent-child relationship, the signals that are received are all invalidated.
FIG. 3 is a diagram showing a signal formed by the encoder. Namely, FIG. 3 shows a signal block for sending a keycode, wherein a portion A denotes a start bit, a portion B denotes a device code, a portion C denotes a keycode, and a portion D denotes a stop bit. The portions A and D maintain a start-stop synchronism of serial transfer. A parity bit may be provided between the portions C and D. Each block has a period Tc.
FIG. 2 is a block diagram illustrating a concrete example of encoder of FIG. 1.
In FIG. 2, reference numeral 331 denotes a device code generator, 332 denotes a device code attacher, and 333 denotes a frequency modulator. Concretely speaking, the device code generator 331 consists of a dip switch or a ROM (read-only memory) which generates a code specific to the device. The device code attacher 332 attaches the device code, start bit and stop bit to the signal from the keycode buffer 35 to form a serial signal that is shown in FIG. 3. The serial signal is input to the frequency modulator 333 which produces frequencies f H and f L to "1" (logic 1) and "0" (logic 0) of the input signals. Here, any frequencies are assigned to f H and f L . For example, when three kinds of frequencies are assigned to f H and f L , respectively, the higher frequencies for "1" are f H1 , f H2 and f H3 , and the lower frequencies for "0" are f H1 , f H2 and f L3 . The frequencies f H , f.sub. L are selected depending upon the output of the device code generator 331.
FIG. 4 denotes a frequency modulator of the case when f H corresponding to "1" is f H1 and f L corresponding to "0" is f L3 . FIG. 4(a) shows signals "1" and "0" , and FIG. 4(b) shows modulated signals of the corresponding frequencies f H1 and f L3 .
In the foregoing description, though three frequencies were assigned to f H and f L , any number of frequencies may be set arbitrarily depending upon the required number of device codes.
FIG. 6 is a diagram which concretely illustrates the constitution of the decoder of FIG. 1.
In FIG. 6, reference numeral 341 denotes a PLL (phase locked loop), 342 denotes a comparator, 343 denotes a data comparator, and 344 denotes a device code generator. Described below is the demodulation operation of the decoder in the cases of the modulation frequencies f H1 and f L3 .
The frequency-dividing ratio of the PLL 341 is set by the output of the device code generator 344. The PLL 341 produces an output E H when the frequency is f H1 for the input waveform of FIG.4(b) and produces an output EL when the frequency is f L3 . Here, the frequency-dividing ratio of the PLL 341 and the threshold values f H , f L of the comparator 342 are so determined that the outputs E H , E L of the PLL 341 will lie within voltage-comparing ranges (V HL to V HH and V LL to V LH ) of the comparator 342. Thus, the PLL 341 produces the voltage E H for f H1 to meet the range V HL to V HH and produces the voltage E L for f L3 to meet the range V LL to V LH . For other frequencies, either one of E H or E L or both of them fall outside the ranges V HL to V HH and V LL to V LH . The comparator 342 compares voltages of outputs of PLL 341 to obtain a waveform FIG. 4(a) from the waveform of FIG. 4(b). The data comparator 343 picks up the device code B (refer to B of FIG. 3) from the above decoded signal block and compares it with the output of the device code generator 344. When they are in agreement, the data comparator 343 produces a coincidence signal.
FIG. 7 is a diagram which concretely illustrates the constitution of the comparator and the data comparator of FIG. 6, and FIG. 8 is a diagram illustrating the operation of FIG. 7.
In FIG. 7, reference numeral 3421 denotes an amplifier which shifts the voltages V H , V L and amplifies the voltages V H , V L , reference numerals 3422 and 3423 denote comparators, 3431 and 3432 denote diodes for preventing the counterflow, and 3433 denotes a resistor.
As an example, voltages V H and V L are divided into three, respectively, to have voltages as indicated in parentheses in FIG. 8. First, considered below is the case of a combination C 1 of V H and V L . When the amplifier 3421 has a zero shift quantity and an amplification factor of 1, the input V H (4.0 V) causes the comparator 3422 to produce an output a which is -Vcc. That is, since the comparator has the input 1 which is 4V and has the input 2 which is 4.2V, the output becomes of a negative sign. When the (+) input is greater than the (-) input, the comparators 3422 and 3423 produce outputs Vcc. Conversely, when the (+) input is smaller than the (-) input, the comparators 3422 and 3423 produce outputs -Vcc. The output b of the comparator 3423 becomes +Vcc. Since the output a is -Vcc and the output b is +Vcc, no current flows through the resistor 3433, and the output c becomes equal to ground potential (GND).
Next, when the input is V Ll (2.0V), the comparator 3422 produces the output a which is -Vcc and the comparator 3423 produces the output b which is -Vcc. Therefore, the output c becomes -Vcc since a current flows through the diode 3432 and the resistor 3433. Here, the output c represents logic "1" when it is +Vcc, represents logic "C" when it is -Vcc, and represents indeterminate when it is GND. In the above-mentioned case C 1 , therefore, the output becomes indeterminate when the input is V H .
Considered below is the case where the amplifier 3421 has an amplification factor n of 1.2 times (n≧2.4/(V H -V L ) and has a shift value Vs of -0.4 (Vs=2.0 -nV L ). When V H1 is input, the comparator 3422 has the input 1 of 4.4V and the output a of +Vcc. Likewise, the comparator 3423 has the input 4 of 4.4V and the output b of Vcc. Therefore, the output c becomes +Vcc (logic "1") Further, when V L is input, the comparator 3422 has the input 1 and the comparator 3423 has the input 4 which are both 2.0V. Through the same processing as above, therefore, the comparators produce outputs a and b which are both -Vcc, and the output c becomes -Vcc (logic "0"). Even in the cases of other combinations (C 2 to C 9 ), the amplification factor and the shift value of the amplifier 3421 should be set in the same manner so that the output c represents logics "1" and "0" for V H and V L , respectively.
As described above, the parent-child relationship can be specified if the amplification factor and the shift quantity are set to the amplifier 3421 of the decoder on the side of the controller, the amplification factor and the shift quantity being adapted to a combination of f H and f L of the frequency modulator of the encoder that converts keycode from the keyboard into serial data.
In this case, the data code needs not be attached to the serial data. In the foregoing description, when both V H and V L have satisfied given values (e.g., V H is greater than 4.2V and V L is smaller than 2.2V), the logic "1" or the logic "0" is determined. When given ranges are satisfied (V LL to V LH for V L e.g , V LL= 2.0V, V LH= 2.4V, and V HL to V HH for V H e.g., V HL= 4.0 V, V HH= 4.4V), furthermore, the logic "1" or the logic "0" may be determined.
Described below is the case when the power source is supplied to the keyboard 3.
In the power supply sending side, a high-frequency coil 41 embedded in a desk 4 of FIG. 1 is driven by a high-frequency power supply 42. On the side of the keyboard 3, the electric power is received by a receiving coil 30 wound on the ferrite, and the voltage required by the circuit is generated by a power supply circuit 39.
In the foregoing description, the signals are transmitted between the controller 2 and the keyboard 3 in the form of light. Not being limited to light, however, the signals may be transmitted in the form of ultrasonic waves or electromagnetic waves.
In the description of the power supply, furthermore, the electric power is supplied to the keyboard 3 based on the combination of the high-frequency coil 41 and the receiving coil 30 in the keyboard 3. It is of course allowable to use generally known solar cells.
According to the present invention as described in the foregoing, the signals can be reliably transmitted using a cordless keyboard without any interface cable even in an environment where a plurality of OA equipment and terminal equipment are operated. Therefore, reliability is maintained just like when the signals are transmitted over the cables, eliminating the need for renewing the cells or recharging the cells.
While a preferred embodiment has been set foth along with modifications and variations to show specific advantageous details of the present invention, further embodiments, modifications and variations are contemplated within the broader aspects o the present inventions, all as set forth by the spirit and scope of the following claims.
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Signals are transmitted using light or the like in a cordless manner between a keyboard and a controller related thereto. The keyboard transmits a signal that indicates a keycode corresponding to a key to the controller in a cordless manner, and the controller sends the keycode signal back to the keyboard. The keyboard compares the transmitted keycode with the received keycode to check whether the keycode signal is correctly transmitted to the controller. When the communication is to be carried out between a plurality of keyboards and the related controllers, a device code specific to the keyboard is attached to the keycode such that the individual keyboards can be identified.
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BACKGROUND OF THE INVENTION
This invention is directed to a receptacle for the disposal of animal waste, and more particularly to a sanitary collapsible receptacle for disposing of animal wastes which includes an integrated scoop stick for directing excrement into the receptacle and an integrated carrying handle having an interlocking closure panel for ensuring the sanitary disposal of the excrement.
The removal and disposal of animal wastes on streets and sidewalks has been a public and environmental problem for many years. Although this problem mainly exists in cities or other crowded areas, it is becoming an increasing concern in suburban and even rural areas.
Many cities and towns now require pet owners to remove any waste produced by their pets or face the risk of receiving a fine or ticket. As a result, various devices have been designed for the pet owner for cleaning up the waste.
One of the recurring problems with various devices for disposing of animal wastes is that these devices, if frequently used, become soiled and present a sanitary problem wherever they are stored. Therefore, it would be desirable to provide a device or product which is inexpensive to purchase, and which may be disposed of after use.
SUMMARY OF THE INVENTION
Generally speaking, in accordance with the invention, a receptacle for the disposal of animal wastes is provided. The receptacle includes a collapsible container having a selectively sealable opening for enabling access to the interior of the container and an integrated handle for carrying the container. The handle has a detachable scoop stick for gathering up animal waste and placing the waste in the container through the opening. Once the waste is in the container, a closure panel is positioned over the container's opening so that the animal waste is maintained in the receptacle.
The animal waste disposal receptacle of the invention is made from a cardboard blank which is appropriately folded and manipulated in order to construct the receptacle. The blank includes a series of panels foldably connected to each other along common fold lines. The panels define the walls of the receptacle container When the blank is assembled. One end panel is connected to a handle panel which is formed with a detachable portion suitable for use as a scoop stick. The remaining portion of the handle panel may be used as a handle for carrying the receptacle during use.
The other end panel of the receptacle includes a partially detachable door or closure element which enables selective access to the inside of the receptacle container. In use, the container closure element is opened so that waste or excrement may be placed inside the container. The container is then sealed by closing the closure element in order to maintain sanitary conditions. Since the receptacle of the invention is made of cardboard, the receptacle is simply disposed of after use.
The receptacle of the invention is normally sold in a collapsed folded condition. The user first applies hand pressure on opposing ends of the collapsed receptacle in order to open the receptacle to its operating condition. In this configuration, the end panels thereof lock into place, forming a box shaped configuration. Then, the scoop stick is punched out from the handle panel. Thereafter, the closure element formed in one of the end panels is pulled out and folded down under the container so that it does not interfere with the operation thereof. Using the scoop stick, the user places the animal waste or excrement into the container. After finishing with the scoop stick, the scoop stick is then inserted into the container. Then, the closure element is placed over the opening into the container and locked into place. The receptacle is then carried to the nearest receptacle for disposal.
Accordingly, it is an object of the invention to provide a receptacle for the disposal of animal wastes.
It is another object of the invention to provide an animal waste receptacle having an integrated carrying handle, scoop stick and closure element.
Yet a further object of the invention is to provide an animal waste receptacle which may be sold in a collapsed condition, but which is operable in an expanded condition.
Still another object of the invention is to provide an animal waste receptacle which ensures the sanitary disposal of animal excrement.
A further object of the invention is to provide a cardboard blank for constructing an animal waste receptacle.
Yet another object of the invention is to provide an animal waste disposal receptacle which is both easy to use and disposable.
Still other objects and advantages of the invention will in part be obvious and Will in part be apparent from the following description.
The invention accordingly comprises the several steps and the relation of one or more such steps with respect to each of the others, and the article of manufacture possessing the features, properties and relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
For a fuller understanding of the invention, reference is made to the following description taken in connection with the accompanying drawings, in which:
FIG. 1 is a top plan view of a blank from which an animal waste disposal receptacle in accordance with the invention may be constructed;
FIG. 2 is a side elevational view of the animal waste disposal receptacle of the invention in a collapsed or packaged condition;
FIG. 3 is a perspective view of the animal waste disposal receptacle of the invention shown in an open or expanded condition and illustrating the removal of the scoop stick from the handle panel;
FIG. 4 is a partial perspective view of the end of the animal waste disposal receptacle shown in FIG. 3;
FIG. 5 is a partial perspective view of the animal waste disposal receptacle of the invention showing the closure element in a closed condition; and
FIG. 6 is a partial perspective view similar to that in FIG. 5, but showing the closure element in a closed condition, with the locking tab thereof in a locked position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, a cardboard unit blank 10 from which the animal waste disposal receptacle of the invention is constructed is shown. Cardboard blank 10 is made from a foldable flexible paper board material preferably having a high acid content for rapid biodegradability. Blank 10 includes a series of panels 12, 14, 16 and 18 foldably connected to each other along fold lines 22.
Panel 12 has a flap attached thereto along fold line 23. In addition, panels 12, 14, 16 and 18 each include a first side flap 24a, 26a, 28a and 30a, respectively, and a second side flap 24b, 26b, 28b and 30b, respectively. Flaps 24a and 24b include sections 34a and 34b, while flaps 28a and 28b also include sections 35a and 35b. All of these flaps and sections are used for constructing the waste disposal receptacle of the invention from cardboard blank 10, as described below.
Panel 18 is foldably connected or attached to a handle panel 42, as shown in FIG. 1. Handle panel 42 includes a scoop stick cut-out 44 defined by perforated line 45.
Panel 12 also includes an end flap 20 and both are formed with a closure element cut-out 46, as best shown in FIGS. 1 and 2. Cut-out 46 is defined by perforated lines or edges 49a, 49b and 51, and is formed with a locking tab 48. Closure element cut-out 46 is pivotally swingable along fold line 22 for selectively opening and closing the opening formed by cut-out 46.
In order to construct the waste disposal receptacle of the invention from blank 10, sections 34a and 34b of closure flap 24a and 24b are placed below and attached to the undersides of closure flaps 26a and 26b. Similarly, sections 35a and 35b of closure flaps 28a and 28b are disposed below and attached to the undersides of closure flaps 30a and 30b. Attachment may be by gluing, stapling or another conventional mechanism. As a result, panels 12 and 18 are now folded inwardly and upwardly. Then, the underside of end flap 20 is attached to the top side of flap 18 adjacent to fold line 22 between panel 18 and panel 42 in order to form a collapsed folded receptacle 11, as best shown in FIG. 2.
Receptacle 11 in FIG. 2 is in a collapsed condition, as previously described, and is suitable for packaging, display and sale purposes. Receptacle 11 may be folded in half along fold line 22 for carrying in a shirt or pants pocket prior to use. Receptacle 11 may include printed matter thereon, including applicable trademarks and directions for use. Preferably, the printed matter is created by soybean based inks, which have a minimal effect on the ecosystem.
In order to erect receptacle 11 so that it is operable for the user, pressure is exerted by the user against the diagonally opposite corners thereof so that closure flaps 24a, 26a, 28a and 30a, and closure flaps 24b, 26b, 28b and 30b lock into position (see FIG. 3). As a result, receptacle 11 now has a generally rectangular box configuration, with handle panel 4 extending upwardly therefrom.
In operation of receptacle 11, the user must remove scoop stick cut-out 44 from handle panel 42. This is achieved by applying pressure on the scoop stick cut-out 44 to release cut-out 44 from panel 42, as shown in FIG. 3. Scoop stick 44 is now ready for pushing and/or scooping animal feces and excrement. Handle panel 42 now includes a handle opening and may be grabbed by the user for carrying receptacle 11.
To operate animal waste disposal receptacle 11, it is also necessary to form an opening therein. This is achieved by first pushing in, and then pulling out closure element 46 so that a window is formed in receptacle 11 (see FIG. 3). Closure element 46 is fully extended below receptacle 11, yet is maintained attached thereto along fold line 22. After closure element 46 has been fully extended, receptacle 11 is now ready for use. Using scoop stick 44, the user may pick up the animal excrement and place it into receptacle 11 through the Window formed therein. Alternatively, receptacle 11 is placed on the ground and scoop stick 44 is used to push the animal excrement into receptacle 11.
Once the inside of receptacle 11 has been filled with the animal excrement, scoop stick 44 is inserted therein. Then closure element 46 is pivoted back over the window of receptacle 11 and locking tab 48 is pulled through slot 52 (see FIGS. 5 and 6) in order to securely lock receptacle 11 for subsequent disposal. As a result, the sanitary disposal of animal feces and excrement is maintained.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in carrying out the above method and in the articles set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in this description is shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
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A receptacle for the disposal of animal wastes is provided. The receptacle includes a collapsible container having a selectively sealable opening for enabling access to the interior of the container and an integrated handle for carrying the container. The handle has a detachable scoop stick for gathering up animal waste and placing the wastes in the container through the opening. Once wastes are in the container, a closure panel is positioned over the opening so that the animal waste is maintained in the receptacle.
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BACKGROUND OF THE INVENTION
This invention relates generally to apparatus for effecting the removal of fibrous material from pallets. More specifically, this invention concerns apparatus for removing a thin layer of fibers from a pallet surface which is not otherwise removed by primary fiber removal apparatus.
When handling large volumes of fiber material during harvesting and initial processing, it is highly advantageous to modularize the fiber material to facilitate storage and transportation thereof. The assignee of the present invention has developed such a system for modularizing fiber material such as seed cotton to expedite handling and processing thereof. One portion of the system is a mechanized seed cotton handling apparatus disclosed in U.S. Pat. No. 3,749,003 issued to Lambert H. Wilkes et al. on Jan. 31, 1973. The seed cotton handling apparatus receives fiber material from mechanical harvesters and compacts the fiber material onto a suitable pallet. The pallet along with the compacted seed cotton may then be transported by conventional trucks to a geographically distant processing plant such as a cotton gin, for example.
Another portion of the system developed by the assignee hereof concerns the continuous feeding of the modularized fiber material to the processing plant. For the above purpose, an apparatus has been developed which receives and unloads modules comprising a pallet with compacted fiber material. A pending commonly assigned U.S. Pat. application Ser. No. 439,846 filed Feb. 6, 1974, now U.S. Pat. No. 3,897,018, of Lambert H. Wilkes et al. discloses, in detail, an embodiment of such a mechanized continuous feeding apparatus.
While the preferred embodiment of the mechanized unloading apparatus disclosed in the pending patent application is efficient and constitutes a substantial advance over the then existing state of the art, greater flexibility is desirable in the construction of the unloading apparatus to increase the variety of pallets which may be handled and to efficiently remove all the fiber material carried by the pallet.
In this connection, it would be desireable to have vertical spacing between the pallet unlloading apparatus and the pallet supporting apparatus to accommodate a wide variety of pallet cross-sectional configurations without requiring frequent adjustments of the spacing. More specifically, it is desireable to space the unloading apparatus such that pallets with or without pull bars can be handled without mechanical interference.
It would, moreover, be advantageous to provide means for efficient removal of fibrous material from the pallet notwithstanding the vertical spacing between pallet supporting apparatus and pallet unloading apparatus. Another highly desireable feature for augmenting flexibility of the mechanized unloading apparatus resides being able to efficiently clean pallets having flat, rough or corrugated surfaces that may be interchangeably used in conjunction with the unloading apparatus.
Recognizing the above features, a need exists for a mechanized pallet unloading apparatus which provides the desireable flexibility.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore a general object of the present invention to provide a novel and continuous feeding apparatus for modularized fiber material.
A more specific object of the present invention is to provide such a novel pallet cleaning apparatus in which a sweeper and a gaseous current cooperate to effect a thorough removal of fibrous material from a pallet surface.
Another object of the present invention is to provide a novel pallet cleaning apparatus in which a sweeper reel is provided to mechanically remove an upper portion of a thin layer of fiber material remaining adjacent to a pallet surface while a gaseous current is provided to effect the aero-dynamic removal of the remaining lower portion of the thin layer of fiber material.
A further object of the present invention is to provide a novel pallet cleaning apparatus in which a sweeper reel removes an upper portion of a thin layer of cotton while simultaneously fluffing a remaining lower portion of the thin layer of cotton to facilitate its subsequent removal by aero-dynamic engagement by an air current which impinges upon the surface of the pallet substantially below the sweeper reel.
Yet another object of the present invention of a pallet provide a novel method of cleaning the surface of a pallet by mechanically engaging the uppermost portion of a thin layer of fibrous material and by aero-dynamically engaging a lower portion of the thin layer to effect a complete cleaning of the surface of the pallet.
A still further object of the present invention is to provide a novel apparatus for cleaning a pallet surface which includes a sweeper reel and an air manifold both of which are positioned to accommodate a relatively wide range of typical pallet depths without requiring frequent adjustment of the space between the sweeper reel and a pallet supporting surface.
The above and many other objects of the present invention are substantially accomplished by a continuous feeding apparatus for modularized fiber material in which a rotatable sweeper device spaced above a generally horizontal pallet surface is adapted to mechanically engage and physically strike fibrous material from an upper portion of a thin layer toward a discharge apparatus. The thin layer typically remains on the pallet after passing below apparatus for removing the bulk of fibers from the pallet. Accordingly, by spacing the sweeper device there is no mechanical interference with and hence no damage to the pallets passing therebelow. Moreover, by providing a plurality of radial blades on the sweeper, the uppermost portion of the thin layer of fibrous material is mechanically engaged by the radially outermost tips of the blades thereby dislodging, decompressing and fluffing the remaining fibrous material on the pallet to facilitate subsequent removal.
To effect the removal of the fluffed fibrous material remaining after the action of the sweeper device, a suitable gas blast apparatus may be provided. The gas blast apparatus is preferably circumferentially disposed with respect to the sweeper device and oriented to direct a gaseous current for impingement on a pallet surface at a position substantially below the sweeper device. In this manner, the gaseous curtain lifts the fluffed fibrous material upwardly and into mechanical engagement with the rotating sweeper device. The cooperating sweeper device thereupon physically throws the fibrous material toward discharge apparatus provided therefor.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and many other objects of the present invention will be apparent to those skilled in the art when this specification is read in conjunction with the appended drawings wherein like reference numerals have been applied to like elements and wherein:
FIG. 1 is a side elevation in partial section illustrating a pallet unloader according to the present invention;
FIG. 2 is a plan view in partial section taken along the line 2--2 of FIG. 1;
FIG. 3 is an elevation in partial cross-section taken along the line 3--3 of FIG. 1 to illustrate the vertical positioning of a rotary sweeper, a transverse conveyor and rotating augers;
FIG. 4 is a partial side elevation illustrating a fiber egress opening;
FIG. 5 is a detail illustration of apparatus for initially engaging and moving pallets;
FIG. 6 is a detail view in partial cross section that illustrates apparatus for cleaning the surface of pallets after the bulk of fibers has been removed therefrom;
FIG. 7 is a detail view taken along line 7--7 of FIG. 6 and illustrates a manifold with orifices to obtain a gaseous curtain;
FIG. 8 is a detail view similar to FIG. 7 which depicts a manifold with elongate slots to effect the generation of a gaseous curtain; and
FIG. 9 is a partial view, similar to FIG. 6, of an alternate embodiment of the sweeper reel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to FIG. 1 an unloading apparatus suitable for removing compressed fibrous material from a pallet for subsequent movement to fiber processing apparatus is depicted. The feeding apparatus includes a generally horizontal bed 20 for supporting and translating pallets longitudinally therealong. The bed 20 includes a loading portion 22 for receiving loaded pallets directly from a flatbed truck or other similar transportation apparatus. The pallets move at a first predetermined speed from the feeding portion 22 to a transition portion 24 which is adapted to translate pallets at both the first predetermined speed and a second predetermined speed. From the transition portion 24, the pallet moves into an unloading portion 26 where the fibrous material is physically removed from the surface of the pallet. Empty pallets progress forwardly along the horizontal bed 20 and enter a suitable conventional pallet stacker 28 where the individual pallets are stacked for subsequent reuse.
Details of the above structure are disclosed and illustrated in pending, commonly assigned, U.S. Pat. Application, Ser. No. 439,846 filed Feb. 6, 1975 by Lambert H. Wilkes et al. for "Method and Apparatus for the Continuous Feeding of Palletized Fiber Materials." The entire disclosure of that application is hereby incorporated by this reference thereto.
The horizontal bed 20 provides a supporting surface for modules consisting of a pallet 30 and compressed fibrous material 32 supported by a generally horizontal surface of the pallet 30. The fibrous material may be seed cotton or any other material that is advantageously handled in modular form.
As the pallet 30 along with its fibrous material 32 advances from the loading portion 22 to the transition portion 24, the pallet advances in the direction illustrated by arrow 34. In the transition portion 24 the pallet advancement speed may be switched from the first predetermined speed at which it leaves the loading portion 22 to the second lower predetermined speed may, for example, be on the order of 15 feet per minute. The second predetermined speed may be selected in the range of 1 to 4 feet per minute.
To switch from the first predetermined speed to the second predetermined speed and vice versa, a suitable clutching mechanism 36 (see FIG. 2) may be provided at one side of the transition portion 24. A suitable manually operated handle 38 may be provided to switch from one predetermined speed to the other. If desired, automatic remote control of the clutching mechanism may also be used.
The cotton module advances from the transition portion 24 (see FIG. 1) to the unloading portion 26 at the second predetermined speed. As the pallet 30 passes through the unloading portion 26, the leading edge 40 of the fibrous material stacked thereon is engaged by suitable apparatus which first removes the bulk of fibrous material and then cleans the pallet surface. Subsequently, the pallet 30 emerges from a fiber egress opening 42 defined in a vertical wall 44 of the unloading portion 26.
It will be appreciated by those skilled in the art that the loading portion 22, the transition portion 24, the unloading portion 26 and the pallet stacker 28 may be used independently of one another depending upon the requirements of a given fiber processing facility.
The loading section 22 may be provided with a plurality of legs 46 having ground engaging rollers 48 mounted at the lower end thereof. The rollers 48 permit the loading section 22 to be moved laterally with respect to the direction 34 of fiber moldule movement therealong (see phantom lines 50, 52 of FIG. 2). The loading portion 22 is adapted for movement to either side of the position in which it is aligned with the transition section 24 to facilitate the loading of cotton modules onto the loading portion 22 from transporting devices such as tractor trailers and the like.
More specifically, a tractor trailer may be driven along side and beyond the loading section 22 so that the back end of the tractor trailer is in general lateral alignment with the forward end of the loading section 22. Alternately, the tractor trailer may be backed into approximate alignment with the loading portion 22. The loading portion 22 may be moved laterally to either side towards a position in alignment with the tractor trailer. The ability to move the loading portion 22 laterally has been found to eliminate unnecessary time consumed by repeatedly backing a tractor trailer into a properly aligned position with respect to the loading portion 22. Accordingly, by moving the loading section 22 laterally as depicted in FIG. 2, the tractor trailer need only be backed into position once thereby reducing waiting time for drivers and improving the speed with which modules can be unloaded.
To off-load a module from a tractor trailer onto the loading portion 22, a chain drive conveyor may be provided. The chain drive conveyor may include a driving sprocket 54, an idle sprocket 58 and a chain 56 supported therebetween. Preferably the chain drive conveyor is positioned generally centrally with respect to the loading portion 22 to uniformly distribute forces on the modules during loading thereof. The upper run of the chain 56 may be supported on a surface 60 that eliminiates catenary droop otherwise naturally occurring when a generally horizontal chain is suspended between two spaced apart points.
A suitable hook device 55 is attached to the forward edge of the pallet for engagement with the chain 56 (see FIG. 5). As the chain 56 (see FIG. 2) is advanced by the driving sprocket 54, the pallet 30 is pulled onto the loading portion 22 from a position on a tractor trailer. While the chain conveyor apparatus is illustrated as centrally disposed with respect to the loading portion 22, the chain conveyor may also be positioned at one side or at any convenient intermediate position of the feeding table 22. As noted, the central position is advantageous in that forces exerted on the module are generally evenly distributed.
The loading portion 22 may include a plurality of short idling rollers 62 adjacent the end thereof which facilitate the support and accommodate movement of a pallet 30 onto the loading portion 22. A plurality of short powered rollers 64 are also provided and comprise a loading conveyor for the advancement of pallets along the loading portion 22 and onto the subsequent transition portion 24. The short powered rollers may be provided with suitably roughened surfaces 66 to facilitate engagement with the bottom of a pallet.
Each short powered roller 64 may be provided with a suitable gear 68 at the outermost end thereof to supply torque necessary to rotate the roller 64 and thereby advance a pallet. To ensure that all the short powered rollers 64 rotate at a uniform angular speed, the gears 68 may be interconnected by suitable chain 70. A suitable source of power 72 may be provided to drive the short powered rollers 64 disposed on each side of the chain conveyor. Moreover, a suitable power source 74 may be provided to drive the sprocket 54 for the chain 56.
The power sources 72, 74 may be hydraulic motors, for example. However, it is also possible to use electric motors or other suitable conventional devices.
Alternatively, the loading portion 22 may be provided with a winch for off-loading modules from a tractor trailer. Such a winch may be provided with a nylon cable for attachment to a pallet 30. Nylon would be a preferred cable material due to its light weight and the absence of coiling tendency normally associated with wire cables. When using a winch, supports for the sprockets 54, 58 are not necessary. Accordingly, the idling rollers 62 and the power rollers 64 may extend continuously between the supporting side rails without interruption to provide an operating area for a chain 56.
A catwalk 76 may be provided to assist the movement of workmen on the loading portion 22 while a pallet is being positioned thereon. The catwalk 76 may extend substantially along the length of the loading portion 22 at a position adjacent to the chain conveyor. Preferably, the catwalk 76 is positioned such that it underlies the idling rollers 62 and the short powered rollers 64. In this manner, the catwalk 76 does not interfere with the movement of the pallet along the feeding table 22.
With continued reference to FIG. 2, a pallet advances from the loading portion 22 onto the transition portion 24 which is provided with a plurality of long powered rollers 78. The service table 24 may also include idling rollers 80, as desired. The long powered rollers 78 may be provided with roughened surface, as in the case of the short powered rollers 64, to facilitate driving engagement with the bottom of a pallet. In addition, each long powered roller 78 may have a suitable gear 82 positioned at the outermost end thereof. A suitable chain 84 may interconnect the clutching mechanism 36 and the gears 84. In this manner, the long powered rollers 78 are constrained to move at a uniform angular velocity and comprise a transition conveyor which may be clutched between the first and second predetermined speeds.
As the pallets move from the transition portion 24 at the second predetermined speed, they enter the unloading portion 26. The unloading portion 26 may include one or more long idling rollers 86 and a plurality of long powered rollers 88. Each long powered roller 88 may be provided with a suitably roughened surface to facilitate engagement with the pallet surface, as was the case with the short powered rollers 64. The long powered rollers 88 constitute a feeding conveyor. Each roller 88 may be provided with a suitable gear 90 at the outermost end thereof and be interconnected by a suitable chain 92 with the gears 90 of the other long powered rollers 88 thereby constraining them to move at a uniform angular speed.
Returning to FIG. 1 it will be noted that the long powered rollers of the transition portion 24 may be driven by a suitable power means 94. Similarly, the long powered rollers 88 of the unloading portion 26 may be driven by a suitable power means 96. As in the case of the power devices in the loading portion 22, the power devices 94, 96 may comprise conventional hydraulic motors, electrical motors or the like.
The leading portion 40 of fibrous material 32 carried by a translating pallet 30 is engaged by a plurality of vertically spaced-apart rotating augers 98 which break loose the fibrous material from the pallet 30 and allow the loosened fibers 100 to drop and coalesce into a pile 102 on a discharge device. Alternately, a plurality of spaced-apart rotating spiked cylinders may be substituted for the rotating augers 98.
Turning now to FIG. 3 it will be seen that the rotating augers 98 are generally horizontally disposed between side walls 104, 106 of a chamber 110. The chamber 110 is defined in part by the side walls 104, 106 and in part by the vertical wall 44 (see FIG. 1) and the generally inclined vertical wall 108 attached to the upper edge of the short vertical wall 44. As a pallet 30 advances past the breaking apparatus, a suitable sweeping apparatus 112 is provided to remove a thin layer of fibrous material adjacent the pallet surface which is not removed by the rotating augers 98. The loosened fibers 100 collect in a pile 102 on a generally transverse conveyor 114.
To aid coalescence of the fibers on the upper moving surface 116 of the transverse conveyor and to inhibit spillage from the surface 116, a suitable deflecting device may be provided in the chamber 110. The deflecting device includes a pivotally mounted movable wall member 120 (see FIG. 1) which is adapted for rotatable movement about its upper edge by connection to a rod 121 pivotally connected to the upstanding side walls 104, 106. To impede loosened fibers 100 from passing between the deflecting wall 120 and the inclined stationary wall 108 a suitable deflecting plate 122 may be provided adjacent the pivotal mounting of the movable wall 120. It will be appreciated by those skilled in the art that the module unloading apparatus may be operated without a deflecting wall 120.
The lower edge of the movable wall is provided with a suitable resilient flashing member 124 which effectively seals the movable wall 120 against the upper moving surface 116. A suitable adjustment mechanism comprising a notched handle 126 that engages a suitable recess of the generally vertical wall 44 may be provided to laterally position the lower edge of the movable wall 120 with respect to the upper moving surface 116 of the transverse conveyor 114.
It will be apparent form FIG. 3 that as the pallet 30 advances beyond the transverse conveyor 114 the pallet passes below the upper moving surface 116 and above the lower moving surface 126 thereof. In this manner the fibrous material piled on the upper moving surface 116 is prevented from falling onto the upper surface of the pallet 30 as it moves toward the pallet stacker 28.
Turning now to FIG. 4 the side wall 106 includes a fiber egress opening 128 through which fibrous material piled on the upper moving surface 116 is removed from the chamber 110. The fibrous material may be deposited in a suction tube 130 (see FIG. 3) for entrainment in an air current conveyor. Such a suction tube 130 may be connected directly to subsequent fiber handling apparatus such as a cotton gin. Alternatively, the transverse conveyor 114 may dump the loosened fibers directly onto other conveying apparatus for movement into fiber processing apparatus.
Turning now to FIG. 6, the leading edge portion of a corrugated metal pallet 30', which may be used with the module feeding apparatus of the present invention is disclosed in more detail. The pallet 30', which may be of the corrugated metal type, is provided with a pull bar 130 at the leading edge portion thereof to which a suitable hook means may be attached in order to move the pallet 30' onto the loading portion 22 of FIG. 1.
The pallet 30' (see FIG. 6) may be provided with a generally horizontal surface having transversely oriented corrugations 132 that enhance stiffness against transverse bending. As the pallet 30' moves in the direction of the arrow 68 along the powered roller 88 and the support roller 86 of the unloading portion 26, a thin layer 134 of fibrous material remains on the pallet surface 132 and in the corrugations. This layer 134 remains since the lowermost disperser reel or horizontal auger 98 must be spaced above the pallet to prevent interference with and possible damage to the pallet 30'. At the advancing end of the pallet 30', the pull bar 130 is positioned slightly below the vertically uppermost portion 136 of the pallet 30'.
The rotary sweeper 112 is positioned between the breaker device including the rotating augers and the discharge device including the transverse conveyor to mechanically engage a portion of the remaining fibrous material of the layer 134 on the pallet surface.
To avoid interference with and damage to a pallet 30', the sweeper reel 112 is spaced above the pallet supporting and translating apparatus such that its lowermost portion does not engage the uppermost portion 136 of the pallet 30'. In this manner the pallet 30' advances longitudinally below the sweeper 112 with no possibility of damage thereto.
Since the pallets 30, 30' used with the present invention may vary in type being used and in thickness, the sweeper 112 may be provided with conventional adjusting screws 113 at each end to permit vertical adjustment thereof. Typically, the sweeper 112 can be adjusted from 2 to 6 inches above the support roller 86 disposed therebelow. Preferably, the sweeper reel 112 is spaced vertically above the uppermost portion 136 of the pallet 30' by a distance of one half to one inch such that a clearance 138 is obtained therebetween even when other types of pallets are used. With the sweeper 112 thus spaced and rotating in a direction such that the lowermost portion thereof moves opposite the direction 68 of pallet advancement, the sweeper 112 mechanically engages an upper portion 140 of the thin layer 134 of fibrous material remaining on the pallet 30'.
The sweeper 112 itself may comprise, for example, a hub member 142 having a rotationally symmetric cross section to which a plurality of generally radially extending vanes 144 are connected. The radially extending vanes 144 are preferably equiangularly spaced about the periphery of the hub member 142 to improve dynamic balancing of the sweeper 112. In addition, the vanes may be fabricated from a suitable flexible material. Both rubber and nylon bristle brush material 144' (see FIG. 9) have been found satisfactory for the blade material. While a larger or smaller number of vanes 144 (FIG. 6) may be used, the present invention uses a six bladed sweeper 112. The use of six blades permits the sweeper 112 to rotate at a lower angular speed than a fewer number of blades while maintaining the same frequency of mechanical contact with the fibrous material. In addition, the angle between adjacent blades of a six bladed sweeper 112 is smaller than a sweeper having fewer blades augmentating a gas blast apparatus to be described.
With rotary sweeper 112 rotating at 650 rpm, for example, the radially extending vanes 144 mechanically engage the upper portion 140 of the thin layer 134 of fibrous material adjacent the surface. As the vanes 144 engage the fibrous material, it is batted back toward the rotating augers 98 or up toward the chamber 110 such that the material may be deposited on the upper moving surface 116 of the generally transverse conveyor. Simultaneously, the actions of the sweeper 112 effectively decompresse and result in fluffing of the fibrous material remaining adjacent the pallet surface in the lower portion 146 of the thin layer 134 by virtue of the fibrous nature of the material and the mechanical engagement of the upper portion 140.
The pallet 30' may be efficiently cleaned by providing a suitable gas blast device which may include a gas manifold 150 to direct a gaseous current in the direction opposed to pallet advancement and in the same direction as the rotary movement of the sweeper 112. The gaseous current is preferably directed toward the clearance 138 substantially below the sweeper 112. More precisely, the gaseous current is preferably directed toward a zone 139 on the surface of the pallet 30. The zone 139 extends between a first point A (see FIG. 6) directly below the lowermost position swept by a vane 144 and second point B approximately two inches from the first point A in the direction of pallet advancement. This positioning of the gaseous current insures that the impinging current will aerodynamically engage and lift the lower portion 146 of the thin layer 134 upwardly into mechanical engagement with the rotary sweeper 112.
The gas blast device distributes the gaseous current longitudinally along the sweeper so that all fibrous material remaining on the pallet will be removed. To eliminate potential mechanical interference with an advancing pallet 30', the gas device must be spaced above the pallet supporting apparatus at least as high as the lowermost portion of the sweeper 112. A position between 3 and 4 inches vertically above the lowermost portion of the sweeper has been found to be satisfactory.
By positioning the gas blast device on the periphery of the sweeper and orienting the device such that the gaseous current flows in a direction generally tangential to the direction of the sweeper rotation, effective cooperation between the sweeper and the gaseous current is facilitated.
The pallet cleaning effects of the gaseous current produced by the gas manifold 150 may be augmented by providing a cowling 154 between the sweeper 112 and the gas manifold 150. The rotating vanes 144 cooperate with the cowling 154 to blow some additional air in the direction of the gaseous current. Preferably the cowling 154 is arcuately configured in a peripheral disposition about the sweeper 112 and subtends a central angle at least as great as that central angle subtended between three serially adjacent vanes 144 of the sweeper 112. The cowling 154 also inhibits fibrous material in the discharge area 155 from returning to the pallet area 157 below the sweeper 112 by providing a physical barrier therebetween. In addition, the cowling increased the efficacy of the sweeper 112 by limiting accessability of fibrous material in the discharge area to the rotating vanes 144 of the sweeper 112.
Turning now to FIG. 7, the gas manifold 150 may comprise, for example, an elongated conduit 156 attached to the cowling 154 and having a plurality of orifices uniformly spaced apart longitudinally therealong. It has been found that 1/16 inch diameter orifices spaced at two inch intervals along the conduit 156 are adequate to provide a plurality of gas jets that define a gaseous current to effect removal of the lower portion 146 of thin layer 134.
An alternate configuration of the gas manifold is depicted in FIG. 8. The conduit 158 is provided with one or more longitudinally aligned elongated slots 160 having a transverse opening of about 1/16 of an inch. While several elongated slots 160 are illustrated, two slots, each extending along the conduit 158, may be used.
Suitable sources of gas may be connected to the manifold 158 to provide a gaseous current. A suitable source of air capable of supplying 30 to 40 cfm at 20 psig has been found sufficient to provide an effective air current when connected to the manifold of FIG. 7. A suitable air source producing 300 to 800 cfm of air at 5 psig would be adequate to produce an air current when connected to the manifold of FIG. 8.
Returning to FIG. 6 the upper moving surface 116 of the transverse conveyor is slidably supported on a table 162. As noted earlier, a movable wall 120 is provided with a rubber flashing 124 to prevent fibers from slipping off the lateral edge of the upper moving surface 116. Analogously, a second rubber flashing 164 may be provided at the opposite edge of the upper moving surface to prevent cotton from inadvertently being displaced from the upper moving belt on that side. The second rubber flashing 164 may be suitably connected by member 166 to the cowling 154.
Since it is possible for some fibrous material to escape from the interaction of the sweeper 112 and the gas blast device, a belt shield 168 may be provided to prevent the fibrous material from being deposited on the upper horizontal surface of the lower extend of the moving belt 126. Such a deposit of fibrous material might eventually accumulate and adversely interfere with the movement of the transverse conveyor around its supporting rollers. The belt shield 168 may comprise sheet metal members 170 suitably connected to a tube 172 so that a clearance of 1/2 inch remains between the uppermost portion of the belt shield 168 and the normal path of movement of the bottom of a pallet.
It should now be apparent that there has been provided in accordance with the present invention an efficient device for removing the fibrous material from the surface of a pallet. It will, moreover, be apparent to those skilled in the art that numerous modifications, variations, substitutions and equivalents may be provided for various features of the invention as disclosed herein. Accordingly, it is expressly intended that all such modifications, variations, substitutions and equivalents that fall within the spirit and scope of the invention as defined in the appended claims be embraced thereby.
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Apparatus and method for removing fibers from fiber-laden pallets is disclosed in which the bulk of fibers is removed in a primary unloading area thus leaving a thin layer of fibers that are removed by a surface cleaning device. The surface cleaning device included a multiple-blade rotary sweeper which is spaced vertically above the uppermost portion of a pallet to enable the pallet to move therebelow without mechanical interference with the rotary sweeper. A cowling encloses a portion of the periphery of the rotary sweeper to increase the efficacy of fiber removal by the rotary sweeper. The rotary sweeper mechanically engages an upper portion of the thin layer and removes it from the pallet. A suitable gas blast device impinges upon the pallet surface at a location substantially below the rotary sweeper to engage a lower portion of the thin layers of fibers. The gas blast device causes fibers to be lifted upward and into mechanical engagement by the blades of the rotating sweeper. The gas blast device may include an elongated conduit having a plurality of uniformly spaced apart orifice openings or having one or more elongated slots through which pressurized air is exhausted.
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BACKGROUND OF THE INVENTION
This application is the U.S. National Phase of PCT Application Number PCT/GB03/00373, filed on 29 Jan. 2003, which claims priority to Great Britain Application Number 0202142.6, filed 30 Jan. 2002.
This invention relates to a watercraft which may be used for sailing using wind power, but which can maintain a level trim when mechanically propelled at high speeds.
1. Field of Invention
Sailing craft can be provided with a displacement mono-hull with a transverse cross-section which tapers downwardly on each side to its keel line, and which increases in cross-section from the bow to a fullest transverse section, and decreases in cross section from the fullest transverse section to the after end. Such a mono-hull shape is suitable for sailing because of its streamlined longitudinal shape when upright and when heeled over.
However, displacement mono-hulled sailing craft as described above are not suitable to be mechanically propelled at high speeds. When mechanical propulsion means, for example an outboard motor or a screw, provide high levels of forward thrust to the after end of the hull, the bow is forced out of the water and the aft sinks lower into the water. This slows the craft because its forward facing profile is increased, which results in a greater resistance against the water. The more power which is provided to the after end of the hull, the greater the bow lift and the water resistance. As a result the maximum speed which can be reached is fixed, regardless of the size of the engine. The object of the present invention is to overcome some of these problems and provide a watercraft with a displacement hull which may be used for sailing and be mechanically propelled at high speeds.
2. Description of the Related Art
A previous attempt to provide a watercraft which may be used for sailing and be mechanically propelled at high speeds is shown in shown in GB2150890 in the name of LANCER YACHT CORPORATION.
GB2150890 discloses a combination sailboat-powerboat hull in the form of a round-bottom, ballasted displacement hull, which is provided with generally horizontal foils which extend along the static water line on both sides of the hull, the forward ends of the foils being faired into the hillsides approximately amidships from where the foils extend rearwardly towards the quarters, and the foils extending out from the hullsides a distance less than the thickness of the boundary layer at sailing hull speed, the undersurface area of the foils being such as to enable the hull to plane when driven under auxiliary power.
It has been found that the watercraft disclosed in GB2150890 does not work as claimed. The “foils” described therein are planing surfaces which project from the hull and disrupt its streamlined shape. As a result the “foils” create drag which is detrimental to the performance of the craft when sailed and in particular when heeled over.
In order to minimise this drag, the “foils” are narrow in shape and do not extend through the boundary layer into the laminar zone. As a result the lifting force provided by the “foils” as they plane over the water when the craft is powered by a motor is very small and does not prevent the aft of the craft from sinking lower into the water.
Therefore, in an attempt to minimise the disruptive effect of the “foils” when sailing, they are made so small as to render the invention redundant.
The present invention is intended to provide a novel approach.
BRIEF SUMMARY OF THE INVENTION
Therefore, according to the present invention a wind driven sailing craft with a hull of the displacement type with a keel or keels, is provided with hydrofoil means adapted to lift the stern of the craft when the craft is propelled forwards in use by power propulsion means acting at the stern of the hull.
The hydrofoil means can comprise a flat hydrofoil element, which is attached in a transverse arrangement by struts to the bottom of the after end of the hull of the sailing craft. When the sailing craft is propelled forwards in use by power propulsion means acting at the stern of the hull, the angle of the hydrofoil is set to provide the optimum level of lift to the aft to maintain the optimum trim level for the particular speed of the craft.
As the speed of the craft changes the angle of the hydrofoil element can be adjusted, either manually or automatically, to provide the optimum level of lift to the aft to maintain an optimum trim level at any speed.
Preferably the sailing craft is mono-hulled with a transverse cross-section which tapers downwardly to its keel line, and which increases in cross-section from the bow to a fullest transverse section, and decreases in cross section from the fullest transverse section to the after end. The keel line of the hull tapers downwardly from the bow and the stern to a base line at the fullest transverse section.
The sailing craft can be provided with a drop, or a swing, keel, which is lowered into position to provide ballast when the craft is sailing, and is raised to reduce drag when the craft is propelled forwards by power propulsion means. Further, the craft can also be provided with internal water ballast tanks which can be filled with water to provide ballast when sailing, and emptied to reduce the displacement when the craft is propelled forwards by power propulsion means.
When the craft is being powered by its sails the hydrofoil is set level to the water flow under the after end of the hull so zero lift and minimum drag are provided and the hull operates as a normal sailing hull. It has been found that the hydrofoil provides stability to the hull when the craft is being sailed and acts as a damper in rough conditions, which are additional benefits.
In one construction the hydrofoil is disposed approximately level with the base line of the hull. However, in another construction the hydrofoil is disposed approximately level with the base line of the drop keel. It has been found that with either of these arrangements when the craft is grounded or removed from the water it can be supported in an upright position by the lowest point of the hull or the keel and the hydrofoil, like a tripod, which is an additional benefit.
Preferably, the hydrofoil element is attached to the bottom of the hull by two struts. The hydrofoil element can be substantially rectangular in shape, with the shorter sides thereof disposed substantially parallel to the direction of the hull. Further, the hydrofoil element can have a streamlined cross-section with an elongated tear-drop shape, which passes through the water with the least drag. The hydrofoil element can be adapted to rotate on a transverse axis to provide variable lift to the stern of the sailing craft.
In one construction the struts are provided with rudder elements adapted to steer the craft. The rudder elements can be fixed aft of the struts, can be provided as part of the struts, or the struts can be the rudder elements. With this arrangement a traditional rudder is not required for the craft, which further reduces drag.
The power propulsion means can be an inboard engine, preferably provided with a screw acting at the stern of the hull. The screw can have a known type of blades which can be rotated to be parallel with the direction of the hull to reduce drag when sailing.
In a preferred construction the hydrofoil element can be rotated from a zero lift angle level with the water flow under the aft end of the hull, to a lift angle of approximately −5 to −8 degrees.
The upper hull of the sailing craft can be shaped with a spray rail feature to shield the operators from wash produced at high speeds.
The system can be used on any sailing craft, but in a preferred construction the invention is applied to a 13 meter ocean-going yacht, with about 6 berths.
The invention also includes a hydrofoil element for use with a wind driven sailing craft with a hull of the displacement type with a keel or keels, which is provided with hydrofoil means adapted to lift the stern of the craft when the craft is propelled forwards in use by power propulsion means acting at the stern of the hull.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be performed in various ways but one embodiment will now be described by way of example and with reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a boat hull according to the present invention;
FIG. 2 is a perspective view of another boat hull according to the present invention;
FIG. 3 a is a diagrammatic front view of the cross sectional contours of the hull shown in both FIGS. 1 and 2 ;
FIG. 3 b is a diagrammatic side view of the hull shown in FIG. 3 a with the cross-sectional lines;
FIG. 4 is a side view of a yacht according to the present invention, arranged for sail operation;
FIG. 5 is a side view of the yacht shown in FIG. 4 arranged for motorised operation;
FIG. 6 a is a diagrammatic front view of the cross sectional contours of the hull shown in both FIGS. 4 and 5 ; and,
FIG. 6 b is a diagrammatic side view of the hull shown in FIG. 6 a with the cross sectional lines.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 shows a displacement boat hull 1 which is shaped for sailing and is approximately 13 meters in length. FIGS. 3 a and 3 b show the cross-sectional contours of the hull 1 . The hull 1 has a broad beam to provide sufficient righting moment to support the sails and provide an adequate lever arm for internal water ballast. In other respects the hull 1 is a shaped for high-speed sailing (approximately 10 knots). As shown in FIG. 1 the hull 1 is provided with a drop keel 2 with a ballast bulb 3 , and a hydrofoil element 4 . The hydrofoil element 4 comprises two struts 5 and an interconnecting horizontal wing 6 . The wing 6 is substantially rectangular in shape with the shorter sides thereof disposed substantially parallel to the direction of the hull 1 . The hydrofoil element is mounted adjacent to the aft 7 of the hull 1 .
In FIG. 2 displacement boat hull 8 is identical to the hull 1 shown in FIG. 1 , except for recess 9 provided on the lower surface. Recess 9 is dimensioned to receive the upper section of the ballast bulb 11 when the keel 10 is raised. Further, struts 12 have been provided with rudder elements 13 to steer the craft.
FIGS. 4 and 5 show a displacement mono-hulled 13 meter sailing yacht 14 . FIGS. 6 a and 6 b show the cross-sectional contours of the hull 15 . This type of yacht is known so further details will not be described here. The yacht 14 has a hull 15 shaped for sailing, a sailing rig 16 and a motorised screw 17 . The hull 15 is also provided with a spray rail ledge 18 to protect the operators of the craft from wash at high speeds. (The shape of the spray rail 18 can be better seen in FIGS. 6 a and 6 b ). The yacht 14 is provided with a hydrofoil element 19 comprising two struts 20 (only one shown) and an interconnecting horizontal wing (not shown). The hydrofoil element is identical to that shown in FIG. 2 with rudder elements 21 provided on the struts 20 , and it is attached to the bottom of the hull 15 , adjacent to the aft 22 of the yacht 14 . The yacht 14 is also provided with a drop keel 23 with a ballast bulb 24 . The hull 15 also features a recess (not shown) into which the upper section of the ballast bulb 24 can fit when the drop keel 23 is raised.
As shown in FIG. 4 the yacht 14 is set for sail operation with the sailing rig 16 arranged to provide propulsion. The wing (not shown) of the hydrofoil element 19 is set level to the water flow under the after end 22 of the hull so zero lift and minimum drag are provided and the hull 15 can operate as normal.
As shown in FIG. 5 the yacht is set for powered operation with the sailing rig 16 lowered. The drop keel 23 has been raised and the upper section of the ballast bulb 24 has been received by the recess (not shown) in the bottom of the hull 15 . When the screw 17 pushes the yacht through the water at high speeds the wing (not shown) of the hydrofoil element 19 is set at a negative angle and the higher water pressure on the underside of the wing creates lift and holds the yacht 14 at a level trim.
As the speed of the yacht changes the wing is adjusted automatically to provide the optimum level of lift to the aft to maintain an optimum trim level. It will be appreciated that the speed of the yacht can be changed by engine speed as well as sea and weather conditions and any angle of turn, so the wing can be set to respond to these changes to maintain a level trim. It will also be appreciated that the correct wing angles required at high speeds will depend on the size, displacement and engine capacity of the craft with which is it used.
The yacht 14 can be provided with internal water ballast tanks on each side of the hull 15 approximately amidships, in order to provided extra righting moment during sailing. The tanks can be filled automatically when the yacht 14 is in sailing mode, as shown in FIG. 4 , and then emptied to reduce weight and displacement when the yacht 14 is in motor mode, as shown in FIG. 5 .
The spray rail 18 protects the occupants of the yacht 14 from water spray created by the high speed of the yacht 14 .
Although the above describes the invention as applied to a displacement mono-hulled sailing craft, it will be appreciated that the invention can also be applied to a multi-hulled sailing craft. Further, a hydrofoil wing can be attached to the underside of the aft of a sailing craft in any appropriate manner, for example by one or three struts. In addition, if desired the hydrofoiling effect can be achieved by a number of hydrofoil wings attached to the underside of the hull in any appropriate manner.
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A wind driven sailing craft is disclosed with a hydrofoil element which provides variable lift to the stern of the craft to maintain a level trim when the craft is operated under power propulsion. The hydrofoil element includes a hydrofoil wing which rotates on a transverse axis to provide the desired lift.
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FIELD OF THE INVENTION
The invention relates to compositions and methods for minimizing breakthrough bleeding in users of progestin-only pharmaceutic preparations, such as contraceptives.
BACKGROUND OF THE INVENTION
The primate menstrual cycle is characterized by a proliferation and regression of the uterine lining under the control of steroid hormones, primarily estrogen and progesterone. It is believed that the staggered cyclic levels of hormones contribute to the growth and shedding of the upper tissue compartment of the uterus.
The endometrium on the uterus is characterized by distinct layers, such as the stratum functionalis and stratum basalis. It is the functionalis which represents the transient upper tissue compartment that is shed during menstruation.
It is believed that the basalis serves as a source of new cells for the regeneration of the functionalis in succeeding cycles. Wilborn & Flowers, Seminars in Reproductive Endocrinology 2:4, 307, 1984; Padykula et al., Biology of Reproduction 40, 681, 1989. If the basalis does serve as a germinal layer, then the effects of damage to the basalis during a given cycle could be manifest in succeeding cycles.
Because endometrial proliferation serves to prepare the uterus for an impending pregnancy, manipulation of hormones and of the uterine environment can serve as suitable targets for contraception. For example, estrogens are known to decrease follicle stimulating hormone secretion by feedback inhibition.
Under certain circumstances, estrogens can also inhibit luteinizing hormone secretion, once again by negative feedback, although under normal circumstances it is believed that the spike of circulating estrogen found just prior to ovulation induces the surge of gonadotrophin hormones that occurs just prior to and resulting in ovulation. High doses of estrogen also can prevent conception probably due to interference with implantation.
Progesterone is responsible for the progestational changes of the endometrium and the cyclic changes of cells and tissues in the cervix and the vagina. For example, progesterone makes the cervical mucus thick, tenacious and cellular. It is believed that thickened mucus impedes spermatozoal transport.
Progesterone has somewhat of an anti-estrogenic effect on the myometrial cells, for example, decreasing the excitability of the smooth muscle cells, and the like. It is known that large doses of progesterone inhibit luteinizing hormone secretion and progesterone injections can prevent ovulation in humans.
The most prevalent form of oral contraception is a pill that combines both an estrogen and a progestagen, the so-called combined oral contraceptive preparations. Apparently, the estrogen and progestagen act in concert to block gonadotrophin release.
Alternatively, there are oral contraceptive preparations that comprise a progestagen only. Such preparations are indicated particularly for individuals who have experienced side effects or an intolerance to the combined preparations or in lactating women because of the lack of an estrogenic effect on lactation.
However, the progestagen-only preparations have a more varied spectrum of side effects than do the combined preparations. A disadvantage of the progestagen-only preparations is the relatively high incidence of bleeding problems, such as, prevalent or heavier menstrual spotting, amenorrhea and more breakthrough bleeding. Thus, the combined preparations are the preferred oral contraceptives in use today. Sheth et al., Contraception 25,243, 1982.
Some of the very common side effects of the progestagen-only oral contraceptives is the increased incidence of menstrual spotting, break. through bleeding, variations in menstrual cycle length and occasionally amenorrhea.
Nevertheless, it would be preferable to have an contraceptive preparation that minimizes the amounts of estrogens and progestagens used. For example, estrogens are known to cause dizziness, nausea, headache and breast tenderness. Thus, a progestagen-only contraceptive would forego such possible problems and be an improvement over the combined preparations if the above-referred to problems of progestagen-only contraceptives also can be remedied. George Washington University Medical Center, Population Reports, Series A, No. 3, September 1975.
Anti-progestins include inhibitors of progesterone synthesis, ligands, such as antibodies, to progesterone and progesterone receptor antagonists. For example, mifepristone (RU486) is a progesterone receptor antagonist. RU486 binds to the progesterone receptor and produces antagonistic effects. Following oral administration, RU486 in the human has a half life of about 20-24 hours. When administered in the luteal phase of the menstrual cycle, RU486 induces luteolysis and vaginal bleeding.
RU486 may act directly on the endometrium to induce vaginal bleeding. RU486-mediated luteolysis appears to be secondary to changes in gonadotrophin secretion and thus the effects are similar to those following exogenous progesterone administration. Baulieu, Science 245, 1351, 1989.
Swahn et al. (Human Reproduction 5(4), 402, 1990) relates to administering RU486 early during the luteal phase prior to implantation. Those authors found that a single dose of RU486 administered on the second day after the LH peak causes a retardation of endometrial development, without upsetting the menstrual cycle. Those authors speculated that it may be possible that the effect on the endometrium may be sufficient to prevent implantation.
SUMMARY OF THE INVENTION
It is an object of the instant invention to provide a method and means of enhancing the value progestin-only pharmaceutical preparations, such as contraceptives.
It is another object of the instant invention to provide a kit and/or program to enhance the every day use of progestin-only pharmaceutical preparations, such as contraceptives.
Those and other objects have been achieved in the development of a method for minimizing uterine bleeding in a female using a progestin-only pharmaceutical preparation comprising administering to said female a biologically effective amount of an anti-progestin.
The invention also relates to a method of birth control comprising administering to a female a composition comprising biologically effective amounts of a progestin and an anti-progestin.
Further, the invention relates to a contraceptive composition comprising a progestin and an anti-progestin.
The invention also relates to an implant intended for subcutaneous or local administration comprising a pharmaceutically acceptable inert core material which would function as a matrix, a progestin and an anti-progestin.
The invention further relates to a kit. comprising a plurality of pills or tablets to be administered sequentially at one per day, wherein said pills or tablets are placebos except for an active agent-containing pill or tablet comprising an anti-progestin.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts the breakthrough bleeding rate per monkey over the course of treatment. Individual monkeys were given a progestin-only contraceptive and intermittent dosing of anti-progestin. Breakthrough bleeding was scored on all days except for the seven days following an RU486 dose. The average duration of bleeding following an RU486.dose was 3.2±1.1 days. The incidence of RU486-induced menses was 100% within 72 hours. Open bars indicate monkeys receiving oral contraceptive, levonorgestrel, only. Stippled bars represent monkeys receiving levonorgestrel and RU486 at days 30, 60, 90, 120, 150 and 180. Cross-hatched bars indicate monkeys receiving levonorgestrel and RU486 at days 90 and 180. The daily dose of levonorgestrel was 10 μg per day orally except on the day when RU486 was given when no progestin was administered. RU486 was administered orally and intermittently at 50 mg per dose.
FIG. 2 depicts serum estradiol and progesterone levels in monkeys of the various treatment groups. The lower limit of detection of estradiol was 12 pg/ml. The lower limit of detection of progesterone was 0.2 ng/ml. The top panel depicts animals receiving progestin only on a daily basis. The middle panel depicts animals receiving progestin daily and RU486 on days 30, 60, 90 and 120. The bottom panel depicts animals receiving progestin daily and RU486 on day 90 only. The progestin was levonorgestrel.
DETAILED DESCRIPTION OF THE INVENTION
The instant invention relates to a method and means for reducing irregular bleeding in those users of progestagen-only pharmaceutical preparations, such as contraceptives. The invention relates to the use of an anti-progestin in combination with the progestagen-only pharmaceutical preparations, such as a contraceptive. For the purposes of the instant invention, progestin and progestagen are considered synonyms.
Progestagen-only pharmaceutical preparations, such as tablets which can be administered orally, vaginal rings, implant systems (biodegradable or not), injectables and transdermal systems, which can be used as contraceptives are known in the art.
For example, commonly used oral contraceptives contain the synthetic progestins, cingestol, ethynodiol diacetate, lynestrenol, norethindrone, norgestrel, quingestanol acetate, levonorgestrel (active ingredient of NORPLANT), norethisterone, chlormadinone, megestrol, desogestrel, gestodene, norgestimate and the like. Fotherby, Journal of Drug Development 4 (2), 101, 1991. Essentially any progestin suitable for use in a progestagen-only pharmaceutical can be used in the practice of the instant invention.
The anti-progestin can be an inhibitor of progesterone synthesis, such as epostane, azastene or trilostane (Creange, Contraception 24, 289, 1981; Drugs of the Future 7, 661, 1982; van der Spuy et al., Clin. Endo. 19, 521, 1983; Birgerson et al., Contraception 35, 111, 1987; U.S. Pat. No. 3,296,255) or a progesterone receptor antagonist, or any such pharmaceutically suitable agent that counteracts the normal biological activity of progesterone, such as antibodies or ligands bindable to progestins or to the progesterone receptor.
A suitable anti-progestin is a progesterone receptor antagonist. For example, RU486, Onapristone, Org 31710 ((6α,11β,17β)-11-(4-dimethylaminophenyl)-6-methyl-4', 5,'-dihyrospiro[estra-4,9-diene-17,2'(3'H)-furan]-3-one), Org 33628 ((11β,17α)-11-(4-acetylphenyl)-17,23-epoxy-19,24-dinorchola-4,9,20-trien-3-one) and Org 31806 ( (7β,11β,17β)-11-(4-dimethylaminophenyl-7-methyl-4', 5'-dihydrospiro[estra-4,9-diene-17,2'(3'H)-furan]-3one) are particularly suitable in the practice of the instant invention. U.S. Pat. No. 4386085.
The anti-progestin can be administered by way of any art-recognized means practiced in the pharmaceutic arts. For example, a suitable anti-progestin may be so formulated so that it can be administered orally, via a skin patch for transdermal absorption, contained within an inert matrix which is implanted within the body and in the implanted state is released slowly, such an implant is taught in U.S. Pat. Nos. 4,957,119 and 5,088,505 and the like.
Thus, pharmaceutic formulations of solid dosage forms include tablets, capsules, cachets, pellets, pills, powders or granules; topical dosage forms include solutions, powders, fluid emulsions, fluid suspensions, semi-solids, ointments, pastes, creams, gels or jellies and foams; and parenteral dosage forms includes solutions, suspensions, emulsions or a dry powder comprising an effective amount of anti-progestin as taught in the instant invention.
It is known in the art that the active ingredient, the anti-progestin, can be contained in such formulations in addition to pharmaceutically acceptable diluents, fillers, disintegrates, binders, lubricants, surfactants, hydrophobic vehicles, water soluble vehicles, emulsifiers, buffers, humectants, moisturizers, solubilizers, preservatives and the like. The means and methods for administration are known in the art and an artisan can refer to various pharmacologic references for guidance, see, for example, "Modern Pharmaceutics" Banker & Rhodes, Marcel Dekker, Inc. 1979; "Goodman & Gilman's The Pharmaceutical Basis of Therapeutics", 6th Edition, MacMillan Publishing Co., New York 1980.
In the case of oral contraceptives, it is known that the kits thereof contain a pill for each day of the month (either 28 days, the lunar month, or 30 days) wherein any one pill may be a placebo or may contain one or more of the active ingredients.
The effective amount of an anti-progestin in the practice of the instant invention can be determined using art-recognized methods, for example, by establishing dose-response curves in suitable animal models and extrapolating therefrom to humans, extrapolating from suitable in vitro systems or by determining effectiveness in clinical trials. The determination of an effective dose is a routine exercise in the pharmaceutic arts. The artisan will take into account various physical parameters of the prospective host such as weight, age and the like.
In like vein, the dosage regimen of the preparation is determinable using art-recognized methods such as establishing a dose response curve in similar primate models or in a suitable in vitro experimental system or by an empirical determination in clinical trials.
It is contemplated, in view of the dynamic state of the endocrine system in primates, that administration of the anti-progestin can be either on a tonic or continuous basis, such as in parallel with administration of a progestin-only oral contraceptive, or on an episodic basis because of the dynamic relationship of the endometrial cells and the long term effects of anti-progestins. Thus, the anti-progestin can be administered in combination with the progestin in the form of a pill or as a co-component in an implant or the progestin can be given in one form and the anti-progestin can be given in another form, for example, the progestin may be given in the form of a pill and the anti-progestin can be delivered as a component of an implant. Alternatively, the progestin can be administered daily whereas the anti-progestin is administered monthly, or at other intermittent intervals.
In the case of the progesterone receptor antagonists RU486, Org 33628, Org 31806 and Org 31710, it is anticipated that a suitable human oral dose will be on the order of 10-250 mg per dose. The amount per dose can be lowered or raised based on the number of doses actually given, that is the interval at which the doses of anti-progestin are administered and characteristics of the individual receiving the treatment and the potency of a particular anti-progestin.
The number of doses can vary from monthly to longer intervals taking into consideration cost, safety and the like. Thus, a suitable regimen is having the anti-progestin administered every thirty days, every sixty days or every ninety days. Alternatively, in the case of contraceptives where many of the pill kits are configured based on the lunar month, the anti-progestin can be administered on the twenty-eighth day of each cycle. Variations of dosage based on route of administration may vary and such changes can be determined practicing known techniques as described above.
All references cited herein are herein incorporated by reference.
The present invention is described further below with respect to specific examples which are tended to illustrate the instant invention without limiting the scope thereof.
EXAMPLE
In the present study, laboratory primates (Macaca fasicularis, n=18), having normal ovulatory menstrual cycles, were assigned at random to one of three groups: Group I (n=6) received 10 μg of levonorgestrel daily by oral ingestion for 180 days. Group II (n=6) was given the same dose regimen of levonorgestrel as in Group I, except that 50 mg of RU486 was administered orally and intermittently on treatment days 30, 60, 90, 120, 150 and 180. Similarly, Group III primates (n=6) received levonorgestrel daily, but RU486 on treatment days 90 and 180. For Groups II and III, levonorgestrel was withheld only on the days that the anti-progestin was given.
Breakthrough bleeding was recorded daily based on presence or absence of blood in the vagina upon insertion of a saline-moistened cotton-tipped applicator. Menstrual bleeding that occurred within 7 days after each RU486 treatment was not counted as breakthrough bleeding.
To determine whether the dose of levonorgestrel reliably blocked ovulation, all primates were bled daily from the femoral vein (3.0 ml) from treatment day 91 to 120, so that serum estradiol and progesterone levels could be determined by radioimmunoassay using known materials and techniques.
Intermittent RU486 treatment in animals receiving a progestin daily markedly reduced irregular menstrual bleeding by 69% on average, whether the interval between treatments of the anti-progestin was 30 or 90 days (p<0.05). However, there was a trend (p>0.05) toward rising breakthrough bleeding in the 2nd and especially 3rd month after RU486 treatment (Group III).
That the daily dose regimen of levonorgestrel effectively blocked ovulation was evident from the absence of overt serum progesterone elevations. The intermittent doses of anti-progestin did suppress transiently mean tonic serum estradiol to below 30 pg/ml for four or five days; otherwise ovarian estrogen secretion was non-episodic (48±11 pg/ml, Group I; 41±6 pg/ml, Group II; and 42±9 pg/ml; Group III).
More importantly, intermittent administration of RU486 significantly reduced irregular menstrual bleeding whether the every 30 day or every 90 day anti-progestin regimen was employed, albeit the anti-progestin impact appeared to fade with less frequent dosing.
The bleeding control effect of RU486 was manifest for two to three months. The anti-progestin may have imparted certain long-lasting functional characteristics in basal endometrial cells. The primate data show the effectiveness of combining progestin with an anti-progestin, without the need for exogenous estrogen, to control endometrial bleeding.
It should be noted that the efficacy of the progestin to block ovulation is not compromised by the intermittent administration of an anti-progestin. See FIG. 2.
While the invention has been described in detail and with reference to certain embodiments thereof, it would be apparent to one skilled in the art that various changes and modifications can be made without departing from the spirit and scope thereof.
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A method for minimizing menstrual bleeding irregularities in individuals using progestin-only pharmaceutical preparations, such as contraceptives, is disclosed.
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This is a continuation of application Ser. No. 415,396, filed Sept. 7, 1982 now abandoned.
BACKGROUND OF THE INVENTION
The cup of this invention is particularly adapted to use with the heating units of the types shown and described in U.S. Pat. Nos. 3,876,861 and 4,160,152, but its utility is not confined to that use. It is desirable for both economic and esthetic reasons to be able to use a moderate temperature, inexpensive plastic such as polypropylene to make cups. However, when a heat conductive stainless steel closure is to be used to cover and seal an opening in the bottom of the cup, so as to provide better heat transfer through the bottom, the use of plastic such as polypropylene poses a problem. The plastic has a high coefficient of expansion as compared with the metal. Furthermore, it tends to take a permanent set, particularly when it is confined near the outer limit of its expansion, and then to contract upon cooling so that a tight circumferential fit between the plastic and the metal becomes progressively looser as the plastic first sets at its outer limit and then contracts inwardly. With the construction of this invention, a moderate temperature, relatively inexpensive plastic can be used to produce a cup with a stainless steel bottom closure sealed and accomodated for differences in expansion and contraction by a thin, e.g. 20 mil, silicone gasket.
One of the objects of this invention is to provide a cup with a plastic body and a metal base closure which will remain liquid-tight after repeated heating and cooling.
Another object is to provide method and apparatus for producing such a cup simply, economically and effectively.
Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawing.
SUMMARY OF THE INVENTION
In accordance with this invention generally stated a cup adapted to use with a warming unit is provided having a plastic body with an open mouth and a base part defining a central opening. The base part has a radially outwardly extending flange around it with axially spaced radially extending generally planar upper and lower surfaces and a continuous rib projecting in a generally axial direction from the lower surface. A metal base closure, of a metal having a lower coefficient of expansion than the plastic, extends continuously over the opening and beyond the radially outer edge of the flange. An annular gasket is mounted between the closure and lower surface of the flange and in continuous engagement with the rib. The closure has a rim staked at spaced areas around its perimeter over the upper radially extending flange surface a distance greater than any anticipated distance of contraction or expansion of the flange relative to the closure upon repeated cycling of heating and cooling.
In making the cup, the gasket is mounted in the bottom closure, the cup is mounted on top of the gasket within the rim of the closure and the rim of the closure is staked simultaneously over the flange at a multiplicity of generally equispaced locations.
The apparatus for forming the cup includes a cup-supporting platform, staking arms pivotally mounted at stations around the platform, a cam mounted for movement toward and away from the platform, means for moving the cam, preferably in the form of a pneumatic cylinder, and a seperate central support for the cup during assembly. The staking arms have at one end a staking finger projecting toward the cup platform, and at another end a cam follower that is engaged by the cam as it travels.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing, FIG. 1 is a view in perspective of a cup of this invention;
FIG. 2 is a view in side elevation of the cup of FIG. 1;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 2;
FIG. 4 is a fragmentary sectional view of a portion of the bottom of the cup without the bottom closure;
FIG. 5 is a top plan view, partly broken away, of the upper portion of one embodiment of apparatus of this invention;
FIG. 6 is a view in side elevation, also partly broken away, and with a cup shown in phantom lines, of the apparatus of FIG. 5, with staking arms omitted for clarity;
FIG. 7 is a fragmentary view in front elevation in the direction indicated by line 7--7 of FIG. 6;
FIG. 8 is a top plan view of a staker arm fixture plate, with knuckles of another staker arm fixture plate, making up the complete staker arm fixture, shown in phantom lines;
FIG. 9 is a view in side elevation of the staker arm fixture plate of FIG. 8;
FIG. 10 is a top plan view of the cup stand and staker arm fixture assembly, with a helical spring shown fragmentarily;
FIG. 11 is a fragmentary view in side elevation of the cup stand, staker arm fixture, support bar and column, and cam of the previous figures;
FIG. 12 is a view in edge elevation of a staker arm; and
FIG. 13 is a view in side elevation of the staker arm shown in FIG. 12.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing for one illustrative embodiment of this invention, and particularly to FIGS. 1 through 4, refefence numeral 1 indicates a cup body made, in this embodiment, of polypropylene. The temperature drop between the cup bottom closure, when exposed to a heating element, and the cup body, with the construction of this invention permits the use of such a medium temperature plastic. The cup body 1 has a side wall 2 with which a handle 3 is integral, and a base part 4. The base part 4 defines an opening 5, which is surrounded by an interior ledge 6 that has a corresponding external generally radially extending surface 7. The base part includes a neck 8 at the lower end of which is a radially outwardly extending annular foot or flange 9. The flange 9 has a radially extending substantially planar upper surface 10, which, with the section 7 and neck 8, defines a channel 13, and a radially extending substantially planar lower surface 11. A continuous, annular rib 12, triangular in transverse cross section, as shown in FIG. 4, projects with its apex downward from the lower surface 11, spaced inboardly from the outer edge of the surface 11.
A bottom closure 15 has a continuous bottom wall 16 and a rim 17. The rim 17 is staked at its upper edge over the upper surface 10 of the flange 9 at substantially equispaced areas around its perimeter, giving a somewhat crenelated appearance, with crenels 18 and merlons 19.
An annular gasket 20, with a flat top surface 21 and a flat bottom surface 22 is mounted closely within the compass of the rim 17, between the upper surface of the bottom wall of the bottom closure and the lower surface of the flange 9. The gasket is preferably made of FDA approved silicone rubber. The apex of the triangular rib 12 is pressed into the top surface 21 of the gasket, and the lower surface of the flange 9 and the upper surface of the gasket are in tight engagement.
The provision of the radially extending substantially planar upper surface 10 is a matter of importance. If, for example, the periphery of the flange is beveled convergently upwardly, and the rim staked over the beveled surface, when the plastic contracts radially with respect to the rim, the rim becomes loose.
Referring now to FIGS. 5 through 13, reference numeral 30 indicates one embodiment of staking machine of this invention. The machine 30 has a base 31 and an upright stanchion 32 fastened to and supported by the base. At the upper end of the stanchion 32, a yoke 33 is secured to the stanchion at one end. The yoke in this embodiment consists of a pair of leaves 34 bridged by a stop 35 that serves as a reinforcing bar as well. A lever 36 is hinged on a pintle 38 carried by and between the leaves 34. A sufficient length of the lever 36 extends beyond the pintle 38 in the direction of the stanchion to extend beneath the stop 35, upon which that end of the lever bears to keep the lever from swinging down into the way. The lever 36 has on its undersurface a locating socket 37.
Intermediate the height of the stanchion 32, and extending in the same direction as the yoke 33, is a support bar 39 with a vertical bore 40 near its outer end, in which a bearing and stand support column 41 is fixedly mounted. The column 41 has a reduced top section 42 and an internally threaded central blind hole 43 extending vertically downwardly from its upper end, through which it opens. A base clevis 45 is mounted on the base, with a horizontal clevis pin 46 a perpendicular to the axis of which is aligned with the axis of the bore 40 and the center of the socket 37.
A pneumatic cylinder 50 has a tailpiece 51 pivotally mounted on the clevis pin 46. The cylinder 50 has the standard pressure and exhaust fittings 53, and a piston rod 54 projecting from the cylinder vertically upwardly. The piston rod 54 carries a head plate 55 on which two drive rods 56 are mounted on diametrically opposite sides. The drive rods 56 are spaced from and straddle the support bar 39, and are mounted at their upper ends in and carry a cam block 57. The cam block 57 is circular in top plan and has a flat bottom surface 58 and a flat top surface 59. Between the top and bottom surfaces, the cam block has side cam surfaces formed at three different angles from the vertical. An upper cam surface 60 in this embodiment has a 30° angle from the vertical; an intermediate cam surface 61, 15°, and a lower cam surface 62, 10°. The cam block has a central bearing channel 63 closely but slidably embracing the column 41 above the support bar 39.
A cup stand or platform 64 and staker arm fixture 65 are mounted on the upper end of the column 41, as shown particularly in FIG. 11. The cup stand has a top surface 70, an interrupted rim 71, a bottom surface 72 and a collar or boss 73 projecting downwardly from the bottom surface 72 at the center of the stand, through which a countersunk hole 74 extends to receive the head of a machine screw 75 threaded into the hole 43 in the column 41.
The staker arm fixture 65 in this embodiment is made up of a top stake arm fixture plate 79, octagonal in plan, and a bottom staker arm fixture plate 80, identical with the top plate 79 except that the top plate 79 is provided with a counterbore 82 to receive the collar 73 of the cup stand. Both the bottom and top plates have four pairs of flat sided knuckles 84 projecting at quadrants, flush with a contiguous surface of the plate on one side and projecting from the plane of the plate on the other. All of the knuckles have pintle holes 85 with their axes in the plane of the side of the plate from which the knuckles project. The bottom plate 80 is inverted with respect to the top plate 79 and rotated 45°, so that knuckles 84 of the bottom plate are intermediate the knuckles 84 of the top plate, as indicated in FIG. 8 and shown in FIG. 10, and the center lines of the knuckle holes of both plates are in the same plane.
Each of staker arms 90 has a staking finger 91 at its upper end, a hinge section 93 intermediate its ends through which a hinge pin hole 94 extends, a spring seating channel 96 and, at its lower end, a cam follower 97. The arms 90 are mounted on the knuckles 84 by pins 95, and are biased to move the cam followers 97 inboardly by a coil spring 100 seated in the channels 96.
A cup clamp or central support 105 in this embodiment is made up of a post 106 with a rounded head end 107 dimensioned to seat in the socket 37, a locating disc 108 mounted intermediate the height of the post and dimensioned to fit closely within the open upper mouth of the cup, a reduced, externally threaded section 109 and a clamp body 111 into which the threaded section 109 is threadedly mounted. A nut 110 on the threaded section 109 above the clamp body 111, serves to hold the clamp body in its desired adjusted position. The clamp body has a cup ledge-engaging flange 112 and a pilot boss 113 sized to provide a slip fit in the opening 5 in the cup, and to stop short of the plane of the lower surface 11 of the flange 9, when the flange 112 of the clamp body engages the surface of the ledge 6 of the cup. The cup clamp is essential to the forming of the cup, serving to locate and support the cup body and to press the rib 12 into indenting engagement with the gasket.
In assembling the cup, a bottom closure 15 is placed on the cup stand, within the ambit of the locating rim 71, with the rim 17 of the closure facing upwardly. The gasket 20 is mounted in the closure, a cup body is placed with its flange within the ambit of the rim, the cup clamp is inserted as shown, in FIG. 6, and the lever 36, which has been raised to permit the insertion of the cup clamp, is lowered to locate the top of the cup clamp and to exert a desired amount of downward pressure of the cup body flange surface on the gasket. The rim of the closure projects above the upper surface of the flange. Compressed air, in this embodiment, is admitted to the lower end of the cylinder 50, causing the piston 54, hence the cam block 57, to move toward the cup stand. The cam surfaces 60, 61 and 62 progressively and simultaneously engage the cam followers 97 of the staking arms 90. The engagement of the cam followers 97 and the continued movement of the cam block forces the arms 90, against the bias of the spring 100, to rock the arms about the pins 95, causing the staking fingers 91 to move radially inwardly against the upper part of the rim 17, staking the rim at eight places simultaneously over the upper surface 10 of the flange 9. The dimensions of the rim and the staking fingers 91 are such that the distance that the resulting crenels overlap the upper surface 10 is greater than any anticipated contraction of the flange. The pressure applied to the cup by the lever 36 acting through the clamp 105 is sufficient to embed the rib 12 in the upper surface of the gasket 20 so that the rest of the surface of the gasket is tight against the lower surface 11 of the flange 9. The amount of contraction of the plastic in the axial direction is slight compared with the contraction in the radial direction, so that the rib 12 can be made short.
Merely by way of illustration, in a cup in which the inside diameter of the open mouth is approximately 3" and the cup body wall is approximately 0.125" thick, the outside diameter of the neck 8 can be 1.75" and its inside diameter (the diameter of the opening 5) 1.50", and the diameter of the flange at the upper surface 10, 1.95". The height of the flange is the thickness of the body wall, in this instance, 0.125". The rib 12 can project 0.010" from the lower surface 11, and be located about 0.12" from the outer edge of the lower surface 11. In the preferred embodiment, the side surface of the flange 9 slopes slightly outwardly upwardly between the lower surface 11 and upper surface 10, for example at 5°, and the gasket, fitting easily but closely within the ambit of the rim of the closure, extends a short distance beyond the perimeter of the lower surface 11. The gasket 20 can be 0.02" thick and 0.45" wide, and the rim of the bottom closure, 1.96" in inside diameter, and 0.27" high above the upper surface of the bottom closure. Under these circumstances, the engagement of the upper surface of the flange by the under surface of the crenels extends inboardly about 0.06" from the outer edge of the upper surface of the flange.
Again, merely by way of illustration, the staking machine base can be about 9" long, the stanchion 32 being mounted about 21/2" from the remote end of the base and extending about 21.30" above the upper surface of the base. The lower surface of the support bar 39 is 9.30" above the top of the base and the bar is 1.50" high. The shoulder of the support column 41 on which the bottom staker arm fixture plate 80 rests is 2.75" above the top surface of the bar 39. The cylinder provides a 1" stroke for the piston rod 54. The height of the rim 71 is 0.15", and the rim is interrupted to provide gaps sufficiently wide to permit the upper ends of the arms 90 to move in. The cam block 57 can be 1.25" high between the bottom surface 58 and top surface 59 and 3" in diameter at the bottom surface. The support bar 39 can be 1" in diameter and the bearing channel 63 only slightly larger. The diameter of the cam block at the top surface can be 2.10". The axial height of the cam surface 60 can be 0.50", of the intermediate side surface 61, 0.30", and of the lower cam surface 62, 0.45". As has been described above, the cam side surface 60 slopes at 30° from the vertical, the intermediate surface 61 at 15°, and the lower surface 62, at 10°, causing the fingers 91 to move in rapidly and thereafter in two additional stages, more slowly but with greater force through the 1" stroke. As can be seen in FIG. 11, where the cam is shown in both its lowermost and uppermost positions, the cam followers are biased to rest on the surface 60, with the line of contact about 0.125" below the top surface 59.
Numerous variations in the construction of the cup and apparatus and the performance of the method, within the scope of the appended claims will occur to those skilled in the art in the light of the foregoing disclosure. Merely by way of example, the dimensions of the cup can be varied. The cup can be made of various other plastic materials such as polyethylene. The gasket can be made of other materials, as long as they have FDA approval and contribute no taste or odor to the contents of the cup. The top surface 21 of the gasket can be provided with a molded annular rib and the lower surface 11 of the flange 9 be made planar, although the provision of the rib 12 on the bottom has advantages. The metal of which the bottom closure is made can be different from stainless steel, although stainless steel is preferred for a number of reasons. The number of staking arms can be increased or decreased. The rim of the bottom closure can be interrupted by slots to facilitate its being staked, but such an arrangement not only requires another operation in the forming of the closure, but its being oriented in a particular way when it is to be staked. The upper surface of the flange of the cup body can be sloped slightly downwardly radially inwardly, but that poses problems in the molding and makes the provision of constant contact between the staked over rim and the uppper surface of the flange more difficult than the use of a planar radial surface. The pneumatic cylinder 50 can be replaced with a hydraulic cylinder or an electrical solenoid, or even a mechanical mechanism. The cup clamp 105 can be operated by a pneumatic, hydraulic or mechanical actuator rather than being put into place manually. Similarly, the loading of the cup components and the operation of the staking device can be automated, if the volume of production warrants it. These are merely illustrative.
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A cup with a plastic body has a base part defining a central opening and a radially outwardly extending flange around the base part and a continuous rib projecting in a generally axially direction from the lower surface of the flange, and a metal base closure of a metal having a different coefficient of expansion from the plastic body. An annular gasket between the closure and the lower surface of the flange is in continuous engagement with the flange rib. The closure has a rim that is staked over the flange a distance greater than any anticipated distance of contraction or expansion of the flange upon repeated cycling of heating and cooling. An apparatus for making the cup includes a cup-supporting platform, staking arms pivotally mounted at generally equispaced stations around the platform and a cam mounted to actuate the arm substantially simultaneously.
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This application is a division of application Ser. No. 08/933,208 filed Sep. 16, 1997 now U.S. Pat. No. 5,821,247.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a novel hydroquinone derivative useful for treating various allergic diseases and a pharmaceutical use thereof. More particularly, the present invention relates to a therapeutic agent for allergic diseases which contains the hydroquinone derivative as an active ingredient.
2. Description of the Prior Art
Allergic reactions which cause allergic diseases are generally classified into types I to IV. Particularly, the type IV reaction has been known to be dominant in atopic dermatitis, contact dermatitis, chronic bronchial asthma, psoriasis, graft-versus-host diseases, and so on. Effectiveness of antihistaminics and chemical mediator release inhibitors against these diseases is limited, and therefore steroids have been used for their therapy. In addition, cyclosporin and taclorims have also been known to be effective for suppression of graft rejection and therapy for graft-versus-host diseases developed after transplantation, and their application has been expanded into therapy for dermatitis Lancet, 339, 1120 (1992); J. Invest. Dermatol, 98, 851 (1992), etc.!. However, such drugs are sometimes disadvantageous. Steroids cause undesirable side effects such as infectious diseases, atrophy of adrenal glands, osteoporosis, diabetes mellitus, and growth inhibition in children. For cyclosporin or taclorims, side effects caused by their immunosuppression effect, such as infectious diseases and diabetes mellitus, would be feared.
The applicant have proposed uracil derivatives which can inhibit type IV allergic reactions (see Japanese Patent Application Laid-open No. 8-109171 which corresponds to EP700908A1). However, development of more potent and safe drugs for treating allergic diseases, especially those responsible for type IV allergic reactions, is still required.
OBJECTS AND SUMMARY OF THE INVENTION
In these situations, the present invention is intended to solve the above mentioned problems. Therefore, the object of the present invention is to provide a novel compound and a therapeutic agent comprising the compound as an active ingredient which are useful for treating various allergic diseases, especially those responsible for type IV allergic reactions.
The inventors have made intensive and extensive studies with a view toward developing a therapeutic agent which is effective for treating various allergic diseases, especially those responsible for type IV allergic reactions. As a result, it has been found that a hydroquinone derivative having a 2,4 (1H, 3H)-pyrimidinedione ring therein markedly inhibits type IV allergic reactions. The present invention is completed.
Accordingly, the object of the present invention is to provide a hydroquinone derivative of formula (I) below or a pharmaceutically acceptable salt thereof and a pharmaceutical composition containing the hydroquinone derivative or pharmaceutically acceptable salt thereof as an active ingredient, especially for treatment of allergic diseases: ##STR2## wherein: R 1 is a phenyl group which is unsubstituted or substituted with a substituent or substituents each independently selected from the group consisting of a halogen atom, a C1-4 alkyl group and a C1-4 alkoxy group;
R 2 is a hydrogen atom or a C1-4 alkyl group;
each of R 3 and R 4 is independently a hydrogen atom or a C1-4 alkyl group;
R 5 is a hydrogen atom or a C1-4 alkyl group;
each of R 6 , R 7 and R 8 is independently a hydrogen atom or a C1-4 alkyl group;
P is a hydroxyl group;
Q is a hydroxyl group, a C1-4 alkoxy group, a C1-18 acyloxy group or an oxo group;
P may form together with Q an ether bond;
R is a hydroxyl group, a C1-4 alkoxy group, a C1-18 acyloxy group or an oxo group, provided that when either of the Q and the R is an oxo group, the other is also an oxo group;
X is a single bond, an --NR 10 -- group or a --CH 2 --NR 10 -- group in which R 10 is a hydrogen atom or a C1-4 alkyl group;
Y is a methylene group or a carbonyl group; and
dotted bonds in a six membered ring represent that the six membered ring has the maximum number of double bonds.
The hydroquinone derivative and pharmaceutically acceptable salt thereof of the present invention are concretely explained as follows.
The hydroquinone derivative of the present invention has an asymmetric carbon atom attached by R 5 and P as shown in formula (I), which leads two types of enantiomers depending on the steric configuration of R 5 and P on the asymmetric carbon atom. In the present invention, both of the enantiomers are included.
The hydroquinone derivative of the present invention contains a hydroquinone-related moiety represented by formula (II): ##STR3## wherein P, Q, R, R 5 , R 6 , R 7 and R 8 are the same as defined for formula (I) above, and dotted bonds in a six membered ring represent that the six membered ring has the maximum number of double bonds.
The moiety of formula (II) has the following three types of variations depending on the P, Q, and R selected therein.
At first, when P forms together with Q an ether bond, the moiety of formula (II) has a chroman-type structure of formula (III): ##STR4## wherein R 5 , R 6 , R 7 and R 8 are the same as defined for formula (I) above; and R 12 is a hydrogen atom, a C1-4 alkyl group or a C1-18 acyl group.
At second, when P is a hydroxyl group and each of Q and R is independently a hydroxyl group, a C1-4 alkoxy group or a C1-18 acyloxy group, the moiety of formula (II) has a hydroquinone-type structure of formula (IV), which is a hydrated form of the above mentioned chroman-type structure (III): ##STR5## wherein R 5 , R 6 , R 7 and R 8 are the same as defined for formula (I); and each of R 11 and R 12 is independently a hydrogen atom, a C1-4 alkyl group or a C1-18 acyl group.
At last, when P is a hydroxyl group and both of Q and R are oxo groups, the moiety of formula (II) has a quinone-type structure of formula (V), which is an oxidized form of the above mentioned hydroquinone-type structure (IV): ##STR6## wherein R 5 , R 6 , R 7 and R 8 are the same as defined for formula (I) above.
In general, these three types of structures of the hydroquinone-related moiety closely relate to one another, and the interconversion between them is reversible see, e.g., J. Org. Chem., 46, 2445 (1981)!. For example, with respect to the interconversion between the chroman-type structure (III) and the quinone-type structure (V), it has been known that α-tocopherol containing the structure of formula (III) (wherein R 5 ═R 6 ═R 7 ═R 8 ═CH 3 , and R 12 ═H) as a partial moiety produces in vivo α-tocopherol quinone which has the structure of formula (V) therein as a partial moiety see, e.g., J. Biol. Chem., 238, 2912 (1963)!.
In formula (I), each of R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 10 is a hydrogen atom or a C1-4 alkyl group such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group and isobutyl group. Particularly preferred is a hydrogen atom or methyl group.
As the hydroquinone-related moiety of formula (II), which is a partial structure of the compound of formula (I) of the present invention, preferred are those in which each of R 5 , R 6 , R 7 and R 8 is a hydrogen atom or a methyl group. Specific examples of such moiety of formula (II) include: for the chroman-type structure of formula (III), 2-methyl-6-hydroxy-2-chromanyl group, 2,8-dimethyl-6-hydroxy-2-chromanyl group, 2,5,8-trimethyl6-hydroxy-2-chromanyl group, 2,7,8-trimethyl-6-hydroxy-2-chromanyl group and 2,5,7,8-tetramethyl-6-hydroxy-2-chromanyl group; for the hydroquinone-type structure of formula (IV),3-(2,5-dihydroxyphenyl)-1-hydroxy-1-metylpropyl group, 3-(2,5-dihydroxy-3-methylphenyl)-1-hydroxy-1-metylpropyl group, 3-(2,5-dihydroxy-3,6-dimethylphenyl)-1-hydroxy-1-metylpropyl group, 3-(2,5-dihydroxy-3,4-dimethylphenyl)-1-hydroxy-1-metylpropyl and 3-(2,5-dihydroxy-3,4,6-trimethylphenyl)-1-hydroxy-1-metylpropyl group; and for the quinone-type structure of formula (V), 3-(1,4-benzoquinon-2-yl)-1-hydroxy-1-metylpropyl group, 1-hydroxy-1-methyl-3-(6-methyl-1,4-benzoquinon-2-yl)propyl group, 3-(3,6-dimethyl-1,4-benzoquinon-2-yl)-1-hydroxy-1-metylpropyl group, 3-(5,6-dimethyl-1,4-benzoquinon-2-yl)-1-hydroxy-1-metylpropyl group and 1-hydroxy-1-methyl-3-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)propyl group. Among them, especially preferred are 2,5,7,8-tetramethyl-6-hydroxy-2-chromanyl group, 3-(2,5-dihydroxy-3,4,6-trimethylphenyl)-1-hydroxy-1-metylpropyl group and 1-hydroxy-1-methyl-3-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)propyl group.
A hydrogen atom of a phenolic hydroxyl group in a benzene ring of the chroman-type structure of formula (III) or the hydroquinone-type structure of formula (IV) may be replaced by a C1-4 alkyl group or a C1-18 acyl group. That is, in formula (III), R 12 is a hydrogen atom, a C1-4 alkyl group or a C1-18 acyl group, and more preferably a hydrogen atom or a C1-18 acyl group. In formula (IV), each of R 11 and R 12 is independently a hydrogen atom, a C1-4 alkyl group or a C1-18 acyl group, and more preferably a hydrogen atom or a C1-18 acyl group. When each of R 11 and R 12 is a hydrogen atom or an acyl groups, corresponding each of OR 11 and OR 12 becomes a hydroxyl group or a hydroxyl group protected with an acyl group. Specific examples of such acyl group include an alkanoyl group such as a formyl group, an acetyl group, a propionyl group, a butyryl group, a pentanoyl group, a hexanoyl group, an octanoyl group, a decanoyl group, a dodecanoyl group, a tetradecanoyl group, a hexadecanoyl group and an octadecanoyl group; and an acyl group containing an aromatic ring such as a benzoyl group, an anisoyl group (methoxybenzoyl group), a phenylacetyl group and a phenylpropionyl group.
In formula (I), R 1 at the 1-position of 2,4 (1H, 3H)-pyrimidinedione ring is a phenyl group unsubstituted or substituted with a substituent or substituents each independently selected from the group consisting of a halogen atom, a C1-4 alkyl group and a C1-4 alkoxy group. The halogen atom used herein is fluorine, chlorine, bromine or iodine, and preferably fluorine, chlorine or bromine. The C1-4 alkyl group is a linear or branched alkyl group, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group or an isobutyl group. The C1-4 alkoxy group is an alkyl-oxy group comprising the alkyl group. The substituted phenyl group of R 1 is exemplified as follows.
Specific examples of the phenyl group substituted with a halogen atom or halogen atoms (e.g., fluorine, chlorine and bromine) include 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2,3-difluorophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 2,6-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl, 2,3-dichlorophenyl, 2,4-dichlorophenyl, 2,5-dichlorophenyl, 2,6-dichlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 2,4-dibromophenyl, 2,5-dibromophenyl, 2,6-dibromophenyl, 2-chloro-4-fluorophenyl, 3-chloro-4-fluorophenyl, 4-chloro-2-fluorophenyl, 4-bromo-2-chlorophenyl, 2,3,4-trifluorophenyl, 2,3,6-trifluorophenyl, 2,4,5-trifluorophenyl, 2,4,6-trifluorophenyl, 2,3,4-trichlorophenyl, 2,4,5-trichlorophenyl, 2,4,6-trichlorophenyl, and 3,4,5-trichlorophenyl groups.
Specific examples of the phenyl group substituted with a C1-4 alkyl group or C1-4 alkyl groups include 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2-ethylphenyl, 3-ethylphenyl, 4-ethylphenyl, 2-propylphenyl, 4-propylphenyl, 2-tert-butylphenyl, 4-butylphenyl, 4-tert-butylphenyl, 4-sec-butylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,6-diethylphenyl, 2,5-di-tert-butylphenyl, 3,5-di-tert-butylphenyl and 2,4,6-trimethylphenyl groups.
Specific examples of the phenyl group substituted with a C1-4 alkoxy group or C1-4 alkoxy groups include 2-methoxyphenyl, 3-methoxyphenyl, 4-methoxyphenyl, 2-ethoxyphenyl, 3-ethoxyphenyl, or 4-ethoxyphenyl group.
The phenyl group of R 1 in formula (I) may be substituted with a plurality of deferent types of substituents. Specific examples of such substituted phenyl group include 2-fluoro-4-methylphenyl, 2-fluoro-5-methylphenyl, 3-fluoro-2-methylphenyl, 3-fluoro-4-methylphenyl, 4-fluoro-2-methylphenyl, 5-fluoro-2-methylphenyl, 2-chloro-4-methylphenyl, 2-chloro-5-methylphenyl, 2-chloro-6-methylphenyl, 3-chloro-2-methylphenyl, 3-chloro-4-methylphenyl, 2-bromo-4-methylphenyl, 3-bromo-4-methylphenyl, 4-bromo-2-methylphenyl, 4-bromo-3-methylphenyl, 3-fluoro-2-methoxyphenyl, 3-fluoro-4-methoxyphenyl, 3-chloro-4-methoxyphenyl, 5-chloro-2-methoxyphenyl, 2-chloro-5-methoxyphenyl, 2-methoxy-5-methylphenyl, 2-methoxy-6-methylphenyl, 4-methoxy-2-methylphenyl and 5-methoxy-2-methylphenyl groups.
In formula (I), R 2 at the 3-position of 2,4 (1H, 3H)-pyrimidinedione ring is a hydrogen atom or a C1-4 alkyl group, and preferably a hydrogen atom or a methyl group. Each of R 3 and R 4 in NR 3 R 4 at the 6-position of 2,4 (1H, 3H)-pyrimidinedione ring in formula (I) is also a hydrogen atom or a C1-4 alkyl group, and preferably a hydrogen atom or a methyl group.
In the compound of formula (I), one containing the chroman moiety of formula (III) has a basic structure in which a 2,4 (1H, 3H)-pyrimidinedione ring is connected to the chroman ring through a --X--Y-- group. Examples of such basic structure include those in which X is an --NR 10 -- group and Y is a carbonyl group, such as 5-(chroman-2-carboxamido)-2,4 (1H, 3H)-pyrimidinedione, 5-(N-methylchroman-2-carboxamido)-2,4 (1H, 3H)-pyrimidinedione, 5-(N-ethylchroman-2-carboxamido)-2,4 (1H, 3H)-pyrimidinedione, 5-(N-propylchroman-2-carboxamido)-2,4 (1H, 3H)-pyrimidinedione and 5-(N-butylchroman-2-carboxamido)-2,4 (1H, 3H)-pyrimidinedione; those in which X is an --NR 10 -- group and Y is a methylene group, such as 5- N-(2-chromanylmethyl)amino!-2,4 (1H, 3H)-pyrimidinedione, 5- N-(2-chromanylmethyl)-N-methylamino!-2,4 (1H, 3H)-pyrimidinedione, 5- N-(2-chromanylmethyl)-N-ethylamino!-2,4 (1H, 3H)-pyrimidinedione, 5- N-(2-chromanylmethyl)-N-propylamino!-2,4 (1H, 3H)-pyrimidinedione and 5- N-butyl-N-(2-chromanylmethyl)amino!-2,4 (1H, 3H)-pyrimidinedione; those in which X is a single bond and Y is a methylene group or a carbonyl group, such as 5-(2-chromanylmethyl)-2,4 (1H, 3H)-pyrimidinedione and 5-(2-chromancarbonyl)-2,4 (1H, 3H)-pyrimidinedione; those in which X is --CH 2 --NR 10 -- group and Y is a methylene group, such as 5- N-(2-chromanylmethyl)aminomethyl!-2,4 (1H, 3H)-pyrimidinedione, 5- N-(2-chromanylmethyl)-N-methylaminomethyl!-2,4 (1H, 3H)-pyrimidinedione,5- N-(2-chromanylmethyl)-N-ethylaminomethyl!-2,4 (1H, 3H)-pyrimidinedione, 5- N-(2-chromanylmethyl)-N-propylaminomethyl!-2,4 (1H, 3H)-pyrimidinedione and 5- N-butyl-N-(2-chromanylmethyl)aminomethyl!-2,4 (1H, 3H)-pyrimidinedione; and those in which X is a --CH 2 --NR 10 -- group and Y is a carbonyl group, such as 5-(chroman-2-carboxamidomethyl)-2,4 (1H, 3H)-pyrimidinedione, 5-(N-methylchroman-2-carboxamidomethyl)-2,4 (1H, 3H)-pyrimidinedione, 5-(N-ethylchroman-2-carboxamidomethyl)-2,4 (1H, 3H)-pyrimidinedione, 5-(N-propylchroman-2-carboxamidomethyl)-2,4 (1H, 3H)-pyrimidinedione and 5-(N-butylchroman-2-carboxamidomethyl)-2,4 (1H, 3H)-pyrimidinedione. These basic structures have the above mentioned R 1 , R 2 , and NR 3 R 4 at the 1-, 3- and 6-positions of the 2,4 (1H, 3H)-pyrimidinedione ring, respectively; and also have R 5 , R 6 , OR 12 , R 7 and R 8 at the 2-, 5-, 6-, 7- and 8-positions of the chroman ring, respectively.
In the compound of formula (I), one containing the hydroquinone moiety of formula (IV) has a basic structure having a 3-phenylpropyl group instead of the 2-chromanyl group in the above mentioned chroman ring-containing basic structure. The 3-phenylpropyl group has a hydroxyl group and R 5 at the 1-position of the propyl moiety thereof, and also has OR 11 , R 8 , R 7 , OR 12 and R 6 at the 2-, 3-, 4-, 5- and 6-positions of the phenyl moiety thereof, respectively.
In the compound of formula (I), one containing the quinone moiety of formula (V) has a basic structure having a 3-(1,4-benzoquinon-2-yl)propyl group instead of the 2-chromanyl group in the above mentioned chroman ring-containing basic structure. The 3-(1,4-benzoquinon-2-yl)propyl group has a hydroxyl group and R 5 at the 1-position of the propyl moiety thereof, and also has R 6 , R 7 , and R 8 at the 3-, 5- and 6-positions of the benzoquinone moiety thereof, respectively.
Proper selection of the substituents of the 2,4 (1H, 3H)-pyrimidinedione ring and the hydroquinone-related moiety of formula (II) can afford preferable hydroquinone derivative of the present invention. That is, selection of a hydrogen atom or a methyl group for R 2 , R 3 , and R 4 on the 2,4 (1H, 3H)-pyrimidinedione ring; R 5 , R 6 , R 7 , and R 8 on the moiety of formula (II); and R 10 in --X--Y--affords the more preferable compound of formula (I). Selection of a methyl for all of R 5 , R 6 , R 7 , and R 8 affords the particularly more preferable compound of formula (I).
Specific examples of such particularly preferable hydroquinone derivative of formula (I) of the present invention include:
for those which have the chroman moiety of formula (III) therein,
6-amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(4-fluorophenyl)-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(4-chlorophenyl)-5- 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(2-chlorophenyl)-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(3-chlorophenyl)-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-1-(4-methylphenyl)-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-1-(4-methoxyphenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-6-methylamino-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-dimethylamino-1-(4-fluorophenyl)-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
5-(6-acetoxy-2,5,7,8-tetramethylchroman-2-carboxamido)-6-amino-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- (6-hydroxy-2,5,7,8-tetramethyl-2-chromanylmethyl)amino!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5-(6-hydroxy-2,5,7,8-tetramethyl-2-chromanylmethyl)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5-(6-hydroxy-2,5,7,8-tetramethyl-2-chromancarbonyl)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- N-(6-hydroxy-2,5,7,8-tetramethyl-2-chromanylmethyl)aminomethyl!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamidomethyl)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione, and
6-amino-3-methyl-5-(N-methyl-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamidomethyl)-1-phenyl-2,4 (1H, 3H)-pyrimidinedione;
for those which have the hydroquinone moiety of formula (IV) therein,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-1-(4-fluorophenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(4-chlorophenyl)-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(2-chlorophenyl)-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(3-chlorophenyl)-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-1-(4-methylphenyl)-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-1-(4-methoxyphenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-6-methylamino-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-6-dimethylamino-1-(4-fluorophenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-dihydroxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyl!amino!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyl!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione,
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyryl!-3-methyl-1-phenyl-2,4 (1H,3H)-pyrimidinedione,
6-amino-5- N- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyl!aminomethyl!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione, and
6-amino-5- 4-(2,5-diacetoxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramidomethyl!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione;
for those which have the quinone moiety of formula (V) therein,
6-amino-3-methyl-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H) -pyrimidinedione,
6-amino-1-(4-fluorophenyl)-3-methyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(4-chlorophenyl)-3-methyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(2-chlorophenyl)-3-methyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(3-chlorophenyl)-3-methyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-3-methyl-1-(4-methylphenyl)-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-1-(4-methoxyphenyl)-3-methyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
3-methyl-6-methylamino-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-dimethylamino-1-(4-fluorophenyl)-3-methyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-3-methyl-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyl!amino!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-3-methyl-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyl!-2,4 (1H, 3H) -pyrimidinedione,
6-amino-3-methyl-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyryl!-2,4 (1H, 3H) -pyrimidinedione,
6-amino-3-methyl-1-phenyl-5- N- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyl!aminomethyl!-2,4 (1H, 3H)-pyrimidinedione,
6-amino-3-methyl-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramidomethyl!-2,4 (1H, 3H) -pyrimidinedione;
and pharmaceutically acceptable salts thereof. Here, the term "a pharmaceutically acceptable salt" means a sodium, potassium, calcium, ammonium, hydrochloride, sulfate, acetate or succinate salt of any of the hydroquinone derivatives which have a dissociating (i.e., salt-forming) functional group.
The hydroquinone derivative of formula (I) of the present invention can generally be prepared by synthesizing an intermediate corresponding to the 2,4 (1H, 3H)-pyrimidinedione moiety and an intermediate corresponding to the moiety of formula (II) separately and then coupling both of the intermediates to each other under an appropriate reaction condition. The intermediate corresponding to the 2,4 (1H, 3H)-pyrimidinedione moiety, 6-amino-2,4 (1H, 3H)-pyrimidinedione, can be prepared, for example, by the method disclosed in Japanese Patent Application Laid-open No. 8-109171 (corresponding to EP 700908A1). With respect to the intermediate corresponding to the moiety of formula (II), an intermediate corresponding to the chroman-type structure of formula (III) can be synthesized, for example, by the method disclosed in U.S. Pat. No. 4,026,907; and an intermediate corresponding to the hydroquinone-type structure of formula (IV) or the quinone-type structure of formula (V) can be synthesized, for example, by the method described in J. Org. Chem., 46, 2445 (1981).
The hydroquinone derivative of formula (I) of the present invention may also be prepared in the following various ways depending on the types of the --X--Y-- groups therein.
For example, a hydroquinone derivative of formula (I) in which --X--Y-- is --NH--CO-- may be prepared by introducing a nitroso or nitro group into a 6-amino-2,4 (1H, 3H)-pyrimidinedione derivative, reducing the resultant to obtain a 5,6-diamino-2,4 (1H, 3H)-pyrimidinedione derivative, and then condensing it with a carboxylic acid corresponding to any of formulae (III), (IV) and (V). The condensation process can be performed, for example, by a conventional method used for peptide synthesis such as a mixed anhydride method, an acid halide method, an activated ester method and a carbodiimide method.
A hydroquinone derivative of formula (I) in which --X--Y-- is --NR 10 --CH 2 -- may be prepared from a 5,6-diamino-2,4 (1H, 3H)-pyrimidinedione derivative and an aldehyde corresponding to formula (III), (IV) or (V) through reductive amination. It may also be prepared by reducing the above mentioned hydroquinone derivative of formula (I) in which --X--Y-- is --NR 10 --CO--.
A hydroquinone derivative of formula (I) in which --X--Y-- is --CH 2 --NR 10 --CO-- may be prepared, for example, through Mannich aminomethylation of the 6-amino-2,4 (1H, 3H)-pyrimidinedione derivative into a 6-amino-5-(aminomethyl)-2,4 (1H, 3H)-pyrimidinedione derivative, followed by condensation with a carboxylic acid corresponding to formula (III), (IV) or (V). The 6-amino-5-(aminomethyl)-2,4 (1H, 3H)-pyrimidinedione derivative may also be prepared from the 6-amino-2,4 (1H, 3H) -pyrimidinedione derivative through Sandmeyer formylation followed by reductive amination.
A hydroquinone derivative of formula (I) in which --X--Y-- is --CH 2 --NR 10 --CH 2 -- may be prepared, for example, from the 6-amino-5-aminomethyl-2,4 (1H, 3H) -pyrimidinedione derivative and an aldehyde corresponding to formula (III), (IV) or (V) through reductive amination thereof. It may also be prepared by reducing the above mentioned hydroquinone derivative of formula (I) in which --X--Y-- is --CH 2 --NR 10 --CO--.
A hydroquinone derivative of formula (I) in which --X--Y-- is --CH 2 -- may be prepared from the 6-amino-2,4 (1H, 3H)-pyrimidinedione derivative and a chloromethyl derivative corresponding to formula (III), (IV) or (V).
A hydroquinone derivative of formula (I) in which --X--Y-- is --CO-- may be prepared from the 6-amino-2,4 (1H, 3H)-pyrimidinedione derivative and a carboxylic acid corresponding to formula (III), (IV) or (V) through Friedel-Crafts acylation.
In the preparation of the hydroquinone derivative of formula (I) of the present invention, after the coupling of a 2,4(1H, 3H)-pyrimidinedione moiety with a hydroquinone-related moiety of any of formulae (III), (IV) and (V), interconversion between the chroman-, hydroquinone- and quinone-type moieties in the resultant coupled compound may be performed.
Reaction conditions for the above mentioned process may be suitably selected depending on the types of the reaction or the reagents employed. In general, conditions commonly employed for those reactions can be used. If necessarly, a process for introduction or elimination of protecting groups may additionally be employed.
The pharmaceutical composition of the present invention, which is concretely a therapeutic agent for allergic diseases, contains the above mentioned hydroquinone derivative of formula (I) or pharmaceutically acceptable salt thereof as an active ingredient. The pharmaceutical composition can be used in various forms, such as an external preparation (ointment, cream, etc.), an oral preparation (tablets, capsules, powder, etc.), inhalant, injection, and so on. For example, for the preparation of an ointment, the hydroquinone derivative or pharmaceutically acceptable salts thereof of the present invention may be mixed into an ointment base such as vaseline, and optionally additives such as an absorption accelerator may be added thereto. For the preparation of tablets, the hydroquinone derivative or pharmaceutically acceptable salt thereof of the present invention may be mixed with excipients (lactose and starch, etc.), lubricants (talk, magnesium stearate, etc.), and other additives.
Dose of the therapeutic agent for allergic diseases of the present invention should be suitably selected depending on sex, age, body weight, disease type and condition of the patient to be treated. For example, for a patient suffered from atopic dermatitis, contact dermatitis, psoriasis, or the like, an ointment containing 0.01 to 10% of the active ingredient may be applied once or several times a day on the diseased portion of the patient. For a patient suffered from any of the above mentioned dermatitises, bronchial asthma, irritable pneumonia, graft rejection caused after transplantation, graft-versus-host diseases, or autoimmune diseases, for example, 0.01 to 100 mg/kg/day of dose in a male adult may be orally administered once a day or divided into several times a day as tablets, capsules or powder.
The hydroquinone derivative or a pharmaceutically acceptable salt thereof according to the present invention exhibits a markedly effective inhibitory action against allergic inflammations, especially those caused by type IV allergic reactions. Accordingly, the hydroquinone derivative or pharmaceutically acceptable salt thereof of the present invention is useful as a therapeutic agent for allergic diseases, especially those caused by type IV allergic reaction. In addition, it can be effectively absorbed through skin by percutaneous administration, and therefore is useful for treatment of various skin diseases such as atopic dermatitis, contact dermatitis and psoriasis. It can also be effectively absorbed through the digestive tract by oral administration, and therefore is useful for treatment of dermatitis covering a wide area, bronchial asthma, irritable pneumonia, graft rejection developed after transplantation, graft-versus-host diseases, autoimmune diseases, and so on. The hydroquinone derivative or pharmaceutically acceptable salt thereof is a non-steroidal material, and therefore advantageously exhibits no steroid-like side effect.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in more detail with reference to the following examples.
EXAMPLE 1
6-Amino-5-(6-hydroxy-2 5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
A mixture of 5,6-diamino-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione (3.02 g, 13 mmol), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (3.58 g, 14.3 mmol) and 4-(dimethylamino)pyridine (0.32 g, 2.6 mmol) was suspended in dichloromethane (60 mL). To the resultant suspension was added dropwise a solution of N,N'-dicyclohexylcarbodiimide (2.82 g, 13.7 mmol) in dichloromethane (60 mL) at room temperature. The reaction mixture was stirred overnight and then filtered. The filtrate was concentrated and then subjected to silica-gel column chromatography, thereby giving the title compound (yield 57%).
TOF-MS (Time-of-flight type mass spectrum): m/z 465 M+H! +
1 H-NMR (CDCl 3 ): δ1.60 (3H, s), 1.90-2.04 (1H, m), 2.08 (3H, s), 2.18 (3H, s), 2.29 (3H, s), 2.30-2.38 (1H, m), 2.54-2.64 (2H, m), 3.34 (3H, s), 4.32 (1H, s), 5.17 (2H, bs), 7.27-7.36 (2H, m), 7.53-7.60 (3H, m), 8.41 (1H, bs)
EXAMPLE 2
6-Amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2(R)-carboxamido)-3-methyl-1-phenyl-2,4 (1H, 3H)-Pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using (R)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid as the intermediate having a chroman-type structure. The data of 1 H-NMR of the compound was compatible with those of the corresponding racemate obtained in Example 1.
α! D +59° (c=2, CHCl 3 )
EXAMPLE 3
6-Amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2(S)-carboxamido)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using (S)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid as the intermediate having chroman-type structure. The data of 1 H-NMR of the compound was compatible with those of the corresponding racemate obtained in Example 1.
α! D -59° (c=2, CHCl 3 )
EXAMPLE 4
6-Amino-1-(4-fluorophenyl)-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-1-(4-fluorophenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 483 M+H! +
1 H-NMR (CDCl 3 ): δ1.60 (3H, s), 1.90-2.05 (1H, m), 2.08 (3H, s), 2.17 (3H, s), 2.28 (3H, s), 2.30-2.40 (1H, m), 2.54-2.64 (2H, m), 3.35 (3H, s), 4.33 (1H, s), 5.15 (2H, bs), 7.30-7.43 (4H, m), 8.43 (1H, bs)
EXAMPLE 5
6-Amino-1-(4-chlorophenyl)-5-(6-hydroxy-2 5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-1-(4-chlorophenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 499 M+H! +
1 H-NMR (CDCl 3 ): δ1.60 (3H, s), 1.90-2.05 (1H, m), 2.07 (3H, s), 2.18 (3H, s), 2.29 (3H, s), 2.30-2.40 (1H, m), 2.55-2.65 (2H, m), 3.34 (3H, s), 4.31 (1H, s), 5.16 (2H, bs), 7.31 (2H, d, 8.4 Hz), 7.53 (2H, d, 8.4 Hz), 8.40 (1H, bs)
EXAMPLE 6
6-Amino-1-(2-chlorophenyl) -5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-1-(2-chlorophenyl) -3-methyl-2,4 (1H, 3H) -pyrimidinedione.
TOF-MS: m/z 499 M+H! +
1 H-NMR (CDCl 3 ): δ1.61 (3H, s), 1.90-2.05 (1H, m), 2.09 (3H, s), 2.19 (3H, s), 2.29 (3H, s), 2.30-2.40 (1H, m), 2.54-2.64 (2H, m), 3.35 (3H, s), 4.30 (1H, s), 5.19 (2H, bs), 7.40-7.55 (3H, m), 7.55-7.65 (1H, m), 8.40 (1H, bs)
EXAMPLE 7
6-Amino-1-(3-chlorophenyl)-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-2,4 (1H, 3H -pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-1-(3-chlorophenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 499 M+H! +
1 H-NMR (CDCl 3 ): δ1.60 (3H, s), 1.90-2.04 (1H, m), 2.08 (3H, s), 2.18 (3H, s), 2.29 (3H, s), 2.30-2.38 (1H, m), 2.54-2.64 (2H, m), 3.34 (3H, s), 4.32 (1H, s), 5.17 (2H, bs), 7.38-7.65 (4H, m), 8.43 (1H, bs)
EXAMPLE 8
6-Amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-1-(4-methylphenyl)-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-3-methyl-1-(4-methylphenyl)-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 479 M+H! +
1 H-NMR (CDCl 3 ): δ1.60 (3H, s), 1.90-2.04 (1H, m), 2.08 (3H, s), 2.18 (3H, s), 2.29 (3H, s), 2.30-2.38 (1H, m), 2.39 (3H, s), 2.54-2.64 (2H, m), 3.34 (3H, s), 4.33 (1H, s), 5.18 (2H, bs), 7.20 (2H, d, 8.5 Hz), 7.34 (2H, d, 8.5 Hz), 8.40 (1H, bs)
EXAMPLE 9
6-Amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-1-(4-methoxyphenyl) -3-methyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-1-(4-methoxyphenyl)-3-methyl-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 495 M+H! +
1 H-NMR (CDCl 3 ): δ1.60 (3H, s), 1.90-2.05 (1H, m), 2.10 (3H, s), 2.19 (3H, s), 2.29 (3H, s), 2.30-2.40 (1H, m), 2.55-2.65 (2H, m), 3.35 (3H, s), 3.87 (3H, s), 4.34 (1H, s), 5.16 (2H, bs), 7.06 (2H, d, 9.0 Hz), 7.25 (2H, d, 9.0 Hz), 8.40 (1H, bs)
EXAMPLE 10
6-Amino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido1)-phenyl-3-propyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5,6-diamino-1-phenyl-3-propyl-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 493 M+H! +
1 H-NMR (CDCl 3 ): δ0.85 (3H, t, 7.2 Hz), 1.48-1.58 (m, 2H), 1.60 (3H, s), 1.90-2.04 (1H, m), 2.08 (3H, s), 2.18 (3H, s), 2.29 (3H, s), 2.30-2.38 (1H, m), 2.54-2.64 (2H, m), 3.69-3.75 (2H , m), 4.32 (1H, s), 5.17 (2H, bs), 7.27-7.36 (2H, m), 7.53-7.60 (3H, m), 8.4 (1H, b)
EXAMPLE 11
5-(6-Hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-6-methylamino-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5-amino-3-methyl-6-methylamino-1-phenyl-2,4 (1H, 3H)-pyrimidinedione.
TOF-MS: m/z 479 M+H! +
1 H-NMR (DMSO-d 6 ): δ1.46 (3H, s), 1.74-1.88 (1H, m), 2.00 (3H, s), 2.07 (3H, s), 2.12 (3H, s), 2.20-2.30 (1H, m), 2.55-2.65 (5H, m), 3.15 (3H, s), 7.25-7.35 (2H, m), 7.48-7.56 (3H, m), 8.5 (1H, b)
EXAMPLE 12
1-(4-Fluorophenyl)-6-dimethylamino-5-(6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamido) -3-methyl-2,4 (1H, 3H)-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 5-amino-6-dimethylamino-1-(4-fluorophenyl)-3-methyl-2,4 (1H, 3H) -pyrimidinedione.
TOF-MS: m/z 511 M+H! +
1 H-NMR (DMSO-d 6 ): δ1.47 (3H, s), 1.75-1.90 (1H, m), 2.01 (3H, s), 2.08 (3H, s), 2.12 (3H, s), 2.20-2.30 (1H, m), 2.37 (6H, s), 2.54-2.64 (2H, m), 3.19 (3H, s), 7.30-7.43 (4H, m), 8.5 (1H, b)
EXAMPLE 13
6-Amino-5-(6-methoxy-2,5,7,8-tetramethylchroman-2-carboxamido)-3-methyl-1-phenyl-2,4 (1H, 3H-pyrimidinedione
The title compound was prepared by repeating substantially the same procedure as Example 1, except using 6-methoxy-2,5,7,8-tetramethylchroman-2-carboxylic acid.
TOF-MS: m/z 479 M+H! +
1 H-NMR (CDCl 3 ): δ1.61 (3H, s), 1.90-2.04 (1H, m), 2.12 (3H, s), 2.21 (3H, s), 2.28 (3H, s), 2.30-2.38 (1H, m), 2.50-2.70 (2H, m), 3.35 (3H, s), 3.62 (3H, s), 5.18 (2H, bs), 7.27-7.36 (2H, m), 7.52-7.60 (3H, m), 8.42 (1H, bs)
EXAMPLE 14
5-(6-Acetoxy-2,5,7,8-tetramethylchroman-2-carboxamido)-6-amino-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
The compound of Example 1 (1.77 g, 3.80 mmol) and pyridine (0.154 mL, 1.90 mmol) were dissolved in dichloromethane (30 mL). To the resultant solution was added dropwise acetic anhydride (0.714 mL, 7.60 mmol) under ice cooling. The resultant reaction mixture was stirred overnight at room temperature, washed with 1N hydrochloric acid and 10% aqueous solution of sodium chloride successively, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was suspended in ethyl acetate and filtered to give the title compound (yield 87%).
TOF-MS: m/z 507 M+H! +
1 H-NMR (CDCl 3 ): δ1.65 (3H, s), 1.90-2.04 (1H, m), 1.93 (3H, s), 2.04 (3H, s), 2.28 (6H, s), 2.30-2.45 (1H, m), 2.50-2.70 (2H, m), 3.35 (3H, s), 4.69 (1H, b), 5.30 (1H, b), 7.26-7.35 (2H, m), 7.52-7.60 (3H, m), 7.89 (0.5H, b), 8.40 (0.5H, b)
EXAMPLE 15
6-Amino-3-methyl-1-phenyl-5- 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyramido!-2,4 (1H, 3H)-pyrimidinedione
The title compound was obtained by repeating substantially the same procedure as Example 1, except using 4-(3,5,6-trimethyl-1,4-benzoquinon-2-yl)-2-hydroxy-2-methylbutyric acid which had been prepared by oxidation of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid with ammonium cerium (IV) nitrate (yield 62%). The title compound was found in plasma a guinea pig as one of metabolites when the compound of Example 1 was orally administered to the guinea pig.
TOF-MS: m/z 481 M+H! +
1 H-NMR (CDCl 3 ): δ1.54 (3H, s), 1.63-1.75 (1H, m), 1.95-2.05 (1H, m), 1.97 (3H, s), 1.99 (3H, s), 2.01 (3H, s), 2.41-2.52 (1H, m), 2.63-2.73 (1H, m), 3.36 (3H, s), 4.11 (1H, s), 5.33 (2H, bs), 7.37-7.40 (2H, m), 7.52-7.63 (3H, m), 8.54 (1H, bs)
EXAMPLE 16
6-Amino-5- 4-(2,5-dihydroxy-3,4,6-trimethylphenyl)-2-hydroxy-2-methylbutyramido!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
The compound of Example 15 (0.48 g, 1.0 mmol) was dissolved in ethanol (3 mL). The resultant solution was stirred at room temperature overnight under hydrogen atmosphere in the presence of 10% Pd/C. The catalyst in the solution was filtered off, and the filtrate was concentrated under reduced pressure to give the title compound.
ESI-MS (Electro-spray-ionization mass stectrum):
m/z 483.21 M+H! +
EXAMPLE 17
6-Amino-5- (6-hydroxy-2,5,7,8-tetramethyl-2-chromanylmethyl amino!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
The compound of Example 14 (64 mg, 1.0 mmol) was dissolved in THF (10 mL). To the resultant solution was added borane-methyl sulfide complex (10M, 0.24 mL, 2.4 mmol). The resultant reaction mixture was refluxed for 5 h. To the resultant was added 1N hydrochloric acid (2.4 mL) under ice-cooling. The resultant mixture was refluxed for 2 h, followed by concentration under reduced pressure. The residue was extracted with dichloromethane after addition of 1N aqueous solution of sodium hydroxide. The organic layer was washed with 10% aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was crystallized by addition of ethyl acetate and ether to give the title compound (yield 35%).
TOF-MS: m/z 451 M+H! +
1 H-NMR (CDCl 3 ): δ1.24 (3H, s), 1.65-1.80 (1H, m), 2.05 (3H, s), 2.10 (3H, s), 2.12 (3H, s), 1.95-2.20 (1H, m), 2.60-2.70 (2H, m), 3.02 (2H, bs), 3.36 (3H, s), 4.24 (1H, s), 4.78 (2H, bs), 7.25-7.35 (2H, m), 7.50-7.60 (3H, m)
EXAMPLE 18
6-Amino-5- N-(6-hydroxy-2,5,7,8-tetramethyl-2-chromanylmethyl)aminomethyl!-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
6-Amino-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione (5.00 g, 23 mmol) was suspended in dimethylformamide (77 mL). To the resultant suspension was added phosphorus oxychloride (2.57 mL, 27.6 mmol), and the resultant mixture was reacted at 60° C. for 3 h. The reaction mixture was diluted with water, and adjusted to ca. pH 12 with sodium hydroxide. The precipitates formed in the reaction mixture was filtered to give a crude product. The crude product was recrystallized from a mixture of ethanol, ethyl acetate and water to give an aldehyde, 6-amino-5-formyl-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione (yield 75%).
To a solution of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamide (1.0 g, 4.0 mmol) in THF (30 mL) was added borane-methyl sulfide complex (10M, 1.9 mL, 19 mmol). The resultant mixture was refluxed for 7 h. To the resultant reaction mixture was added 1N hydrochloric acid (9.6 mL) under ice-cooling, and the resultant mixture was further refluxed for 2 h followed by concentration under reduced pressure. The residue was extracted with ethyl acetate after addition of 1N aqueous solution of sodium hydroxide. The organic layer was washed with 10% aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica-gel column chromatography to give an amine, 2-aminomethyl-6-hydroxy-2,5,7,8-tetramethylchroman (yield 55%).
The aldehyde (204 mg, 0.83 mol) and the amine (353 mg, 1.25 mol) thus prepared were dissolved in dichloroethane (4 mL), and the solution was heated at 70° C. for 7 h to react with one another. The resultant reaction mixture was cooled to room temperature and then sodium triacetoxyborohydride (352 mg, 1.66 mmol) was added thereto. The mixture was allowed to react at room temperature overnight. The reaction mixture was acidified with diluted hydrochloric acid, adjusted to pH 8-9 with sodium hydroxide, and then extracted with dichloromethane. The organic layer was washed with 10% aqueous solution of sodium chloride, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and then crystallized from ethyl acetate/ethanol to give the title compound (yield 26%).
TOF-MS: m/z 466 M+E! +
1 H-NMR (DMSO-d 6 ): δ1.09 (3H, s), 1.40-1.60 (1H, m), 1.99 (3H, s), 2.03 (3H, s), 2.07 (3H, s), 1.85-2.15 (1H, m), 2.50-2.80 (4H, m), 3.12 (3H, s), 3.56 (1H, d, 12 Hz), 3.75 (1H, d, 12 Hz), 5.40 (2H, bs), 7.10-7.26 (2H, m), 7.40-7.55 (3H, m)
EXAMPLE 19
6-Amino-5-(N-butyl-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxamidomethyl)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione
Reductive amination of 6-amino-5-formyl-3-methyl-1-phenyl-2,4 (1H, 3H) -pyrimidinedione with N-butylamine was performed in substantially the same manner as Example 18 to thereby give an intermediate, 6-amino-5-(N-butylaminomethyl)-3-methyl-1-phenyl-2,4 (1H, 3H)-pyrimidinedione. The intermediate was reacted with 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid by a conventional condensation method to give the title compound (yield 36%).
1 H-NMR (CDCl 3 ): δ0.95 (3H, t, 7.2 Hz), 1.33 (2H, t of q, 7.2 Hz, 7.2 Hz), 1.57 (3H, s), 1.60-1.75 (3H, m), 2.03 (3H, s), 2.15 (3H, s), 2.17 (3H, s), 2.45-2.68 (3H, m), 2.45-2.65 (2H, m), 3.32 (3H, s), 3.52-3.67 (1H, m), 3.80-3.95 (1H, m), 4.28 (1H, bs), 4.41 (1H, d, 16 Hz), 4.52 (1H, d, 16 Hz), 5.85 (b), 7.13-7.32 (2H, m), 7.48-7.60 (3H, m)
Evaluation 1
Inhibition of picryl chloride-induced dermatitis
Effect of the compounds of the present invention on picryl chloride-induced dermatitis, which is a typical model of type IV allergic inflammation, was estimated by the Asherson's method Immunology, 15, 405 (1968)! in the following manner.
A 7% (w/v) solution of picryl chloride in acetone (0.1 mL) was applied on a portion of the abdominal skin of each of ICR male mice to sensitize the mice. After 7 days, a 1% (w/v) solution of pioryl chloride in acetone (0.02 mL) was applied on the ears of the individual mice to induce allergic reaction. Just after the challenge, 0.04 mL of acetone (control) or a 0.25-2.5% (w/v) solution of the test compound in acetone was applied on the ear. Increase of the ear thickness of the individual mice was measured at 24 h after the challenge, and inhibitory effect of the test compound on the dermatitis was estimated based on the difference in ear thickness between before and after the induction of the allergic reaction.
The hydroquinone derivative of the present invention had inhibitory effect on swelling as exemplified below. The results show that the hydroquinone derivative of the present invention is effectively absorbed through skin and inhibits dermatitis at the diseased portion by percutaneous administration.
______________________________________ Concentration InhibitionCompound (%) (%)______________________________________Example 1 0.25 69Example 2 0.75 65Example 3 0.75 69Example 11 0.75 44Example 13 2.50 33Example 14 0.75 53Example 15 0.75 70Example 17 0.75 80Example 19 0.25 49______________________________________
Evaluation 2
Inhibition of albumin-induced asthma
Effect of the compounds of the present invention on albumin-induced asthma was estimated in the following manner.
Inhalation of 1% ovalbumin using ultrasonic nebulizer into Hartley male guinea pigs was performed 10 min/day over 8 days to sensitize the guinea pigs. One week after the last sensitization, inhalation of 2% ovalbumin was performed for 5 min. to induce allergic reaction. Metyrapone (10 mg/kg, i.v.) was adminisered at 24 h and 1 h before the challenge, propylene glycol (control) or a solution of the test compound in propylene glycol was orally administered at 1 h before and 3 h after the challenge, and pyrilamine (10 mg/kg, i.p.) was intraperitoneally administered at 30 min before the challenge. Air way resistance was measured by double flow plethysmography at 1 min, 4 h, 5 h, 6 h, 7 h, and 8 h after the challenge, and inhibitory effect of the test compound on the asthma was estimated based on the measurements obtained.
As a result, the compound of Example 1 (100 mg/kg) showed 62% inhibition on the air way reaction at 1 min after the challenge, and 50% inhibition on the air way reaction (AUC) during 4-8 h after the challenge. The results show that the hydroquinone derivative of the present invention is effectively absorbed through the digestive tract and inhibits asthma by oral administration.
Formulation 1
Water soluble ointment
Water soluble ointment of the following formulation was prepared by a conventional manner.
Contents in 2 g of the ointment
The compound of Example 1 40 mg
Poly(ethylene glycol) 400 1372 mg
Poly(ethylene glycol) 4000 588 mg
Formulation 2
Tablets for oral administration
Tablets of the following formulation were prepared by a conventional manner.
Contents in a tablet
the compound of example 1 100 mg
Lactose 353 mg
calboxymethylcellulose calcium 30 mg
hydroxymethylcellulose 7 mg
magnesium stearate 5 mg
crystalline cellulose 5 mg
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Disclosed is a hydroquinone derivative or a pharmaceutically acceptable salt thereof, the hydroquinone derivative being represented by formula (I): ##STR1## wherein R 1 is a phenyl group which is unsubstituted or substituted with a substituent or substituents each independently selected from the group consisting of a halogen atom, a C1-4 alkyl group and a C1-4 alkoxy group;
R 2 is a hydrogen atom or a C1-4 alkyl group;
each of R 3 and R 4 is independently a hydrogen atom or a C1-4 alkyl group;
R 5 is a hydrogen atom or a C1-4 alkyl group;
each of R 6 , R 7 and R 8 is independently a hydrogen atom or a C1-4 alkyl group;
P is a hydroxyl group;
Q is a hydroxyl group, a C1-4 alkoxy group, a C1-18 acyloxy group or an oxo group;
P may form together with Q an ether bond;
R is a hydroxyl group, a C1-4 alkoxy group, a C1-18 acyloxy group or an oxo group, provided that when one of said Q and said R is an oxo group, the other is also an oxo group;
X is a single bond, an --NR 10 -- group or a --CH 2 --NR 10 -- group in which R 10 is a hydrogen atom or a C1-4 alkyl group;
Y is a methylene group or a carbonyl group; and
dotted bonds in a six membered ring represent that said six membered ring has the maximum number of double bonds.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a surge protection device for protecting an on-board power supply system of an electric vehicle against an electric voltage surge and to a corresponding method and to an electric vehicle having the surge protection device.
[0002] A socket with a module for additional functions is already known from EP 0 786 833 B1. The additional functions are primarily related to achieving surge protection of consumers which are connected to the socket.
[0003] EP 0 786 833 B1 describes a module in the case of which the height of the insulation base must not be changed. The design of a present socket cavity and the design of the components of the module which are to be inserted in said socket cavity are matched to one another in terms of their shape. In the case of the module described in that document, a printed circuit board is provided which runs parallel to the bottom of the present insulation base and which has at least two corners which accommodate surge protection components.
[0004] The printed circuit board, in turn, is equipped for electrical connection with resilient contacts, wherein the sockets have blade contacts which produce the necessary electrical connection when the parts are inserted and joined to one another.
[0005] A socket, in particular a safety socket with a retrofittable surge protector is already known from German Utility Model DE 295 07 448 U1. The surge protector in that document is designed as a support part with shaped portions for a circuit board, wherein the circuit board bears necessary electrical components. In the case of the safety socket described in that document, the support part has apertures in a bottom section, through which apertures electrical connection lines for the surge protection device run.
[0006] DE 20 2008 008 905 U1 describes a surge protection device for insertion, including retrospective insertion, in connection sockets, distribution sockets and/or sockets for flush-mounted fitting or surface installation, wherein the sockets have a fastening plate, also referred to as support ring.
[0007] The surge protection device described in that document has a circuit board which accommodates the surge protection elements and a support part with shaped portions for the circuit board and electrical connection means, wherein the support part has an annular-strip-shaped integral extension which surrounds the socket insert in the assembled state.
SUMMARY OF THE INVENTION
[0008] The present invention provides a surge protection device for protecting an on-board power supply system of an electric vehicle against an electric voltage surge.
[0009] Accordingly, what is provided is a surge protection device having:
an input device, which is designed as a current connection of the electric vehicle; a protective device, which is coupled to the input device at an input and has at least one surge arrester for diverting a voltage surge; and an interface device, which, owing to a coupling to an output of the protective device and to the on-board power supply system, is configured to protect the on-board power supply system of the electric vehicle against electric voltage surges.
[0011] The invention also provides a method for protecting an on-board power supply system of an electric vehicle against an electric voltage surge, according to.
[0012] Accordingly, what is provided is a method having the following method steps: coupling an input device of a surge protection device of the electric vehicle to a charging device and coupling a protective device of the surge protection device to the input device via an input of the protective device; providing a surge arrester in the protective device for diverting a voltage surge; and coupling the output of the protective device to the on-board power supply system via an interface device in order to protect the on-board power supply system of the electric vehicle against electric voltage surges.
[0013] The present invention also provides an electric vehicle having a surge protection device.
[0014] The concept of the invention is that of designing a means for lightning protection and surge protection in an electric vehicle at a point which is downstream of a female charging connector of the electric vehicle.
[0015] This advantageously permits destruction of electric components in the on-board power supply system of the electric vehicle by surge-voltage pulses during charging of the vehicle battery to be avoided. The surge protection device can be provided at a central point downstream of the female charging connector in the electric vehicle.
[0016] By means of a central surge protector which is connected downstream of the female charging connector in the electric vehicle, the high-voltage electrical components of the on-board power supply system of the electric vehicle can be configured for air gaps and creepage paths according to in each case the optimum surge class.
[0017] As a result, installation space and costs can be saved in the case of the on-board electrical power supply system of the electric vehicle since the high-voltage electrical components of the electric vehicle and/or the on-board electrical power supply system itself do not require respectively separate surge protection systems.
[0018] According to one embodiment of the invention, provision is made for the input device to be configured to be coupled to a charging device. This enables, in a simple and reliable manner, the electric vehicle to be charged with electrical energy provided by the charging device.
[0019] According to an embodiment of the invention, provision is made for the at least one surge arrester to be designed to divert a voltage surge of up to 1.5 kV or of up to 3 kV or of up to 6 kV or of up to 10 kV. As a result, surge protection can advantageously be provided for the on-board power supply system of the electric vehicle.
[0020] According to an embodiment of the invention, provision is made for the at least one surge arrester to be designed such that a voltage of less than 1.5 kV is present owing to the diversion of the electric voltage surge when the electric voltage surge appears at the output of the protective device.
[0021] According to an embodiment of the invention, provision is made for the surge arrester to be designed as a gas-filled surge arrester or as a gas discharge tube. As a result, if a component-specific ignition voltage is exceeded in the gas discharge tube, it is advantageously possible to ignite a gas discharge and the terminal voltage across the surge arrester is reduced by an arc discharge.
[0022] According to an embodiment of the invention, provision is made for the surge arrester to be designed as a varistor. This advantageously allows the surge arrester to absorb large powers within a short response time of under one nanosecond or of under one microsecond without being destroyed.
[0023] According to an embodiment of the invention, provision is made for the surge arrester to be designed as a suppressor diode. As a result, a surge arrester which does not cause a voltage breakdown of the voltage to be protected and which therefore is ready to be used again after response even without current interruption can advantageously be provided.
[0024] According to an embodiment of the invention, provision is made for the interface device to be designed to be coupled to at least one electrical consumer or to a plurality of electrical consumers of the electric vehicle and to protect the at least one coupled electrical consumer or the coupled electrical consumers against the electric voltage surge. By means of a central surge protection unit downstream of the female charging connector, all of the electrical components which are connected downstream of the central surge protection unit can be dimensioned with the simplest protection requirements.
[0025] The described configurations and developments may be combined with one another in any way.
[0026] Further possible configurations, developments and implementations of the invention also comprise combinations that are not explicitly cited of features of the present invention described above or below with reference to the exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The appended drawings are intended to impart further understanding of the embodiments of the invention. They illustrate embodiments and are used to clarify principles and ideas of the invention in conjunction with the description.
[0028] Other embodiments and many of the stated advantages emerge with regard to the figures. The illustrated elements of the drawings are not necessarily shown to scale with respect to one another.
[0029] In the drawings:
[0030] FIG. 1 shows a schematic illustration of a surge protection device for protecting an on-board power supply system of an electric vehicle against an electric voltage surge according to one embodiment of the invention;
[0031] FIG. 2 shows a schematic illustration of an electric vehicle having a surge protection device for protecting an on-board power supply system of an electric vehicle against an electric voltage surge according to another embodiment of the invention; and
[0032] FIG. 3 shows a schematic illustration of a flow chart of a method for protecting an on-board power supply system of an electric vehicle against an electric voltage surge according to yet another embodiment of the invention.
DETAILED DESCRIPTION
[0033] In the figures of the drawing, identical reference signs denote identical or functionally identical elements, components or method steps unless stated otherwise.
[0034] FIG. 1 shows a schematic illustration of a surge protection device for protecting an on-board power supply system of an electric vehicle against an electric voltage surge according to one embodiment of the invention.
[0035] A surge protection device 100 for protecting an on-board power supply system 24 of an electric vehicle 20 against an electric voltage surge comprises an input device 105 , a protective device 110 and an interface device 115 .
[0036] Electric voltage surges may be disturbance signals which occur in a power network or in an electrical power grid of a charging device 30 , such as lightning strikes, surge pulses or other disturbances that occur when electrical connection couplings fail.
[0037] The input device 105 of the surge protection device 100 can be designed as a current connection of the electric vehicle 20 . The input device 105 can be designed as a female charging connector or a charging socket for receiving a plug-in connector for charging the electric vehicle 20 .
[0038] The protective device 110 of the surge protection device 100 can be coupled to the input device 105 at an input 110 a of the protective device 110 and have at least one surge arrester 111 for diverting the electric voltage surge.
[0039] The interface device 115 of the surge protection device 100 , owing to the coupling of an input 110 b of the protective device 110 to the on-board power supply system 24 , for example, is configured to protect the on-board power supply system 24 of the electric vehicle 20 against the electric voltage surge.
[0040] The interface device 115 of the surge protection device 100 can be designed, for example, as a distributor unit, which has a plurality of electrical components, such as warning lights, programmable logic controllers and other automation components and supply sockets, for example.
[0041] Furthermore, the input device 105 of the surge protection device 100 can be configured to be coupled to a charging device 30 .
[0042] In this case, the surge protection device 100 provides a central protective function for all of the electrical components which are coupled to the on-board electrical power supply system 24 of the electric vehicle 20 , by the common protection of all of the electrical components using the upstream protective device 110 of the surge protection device 100 .
[0043] Owing to a central protection unit downstream of the input device 105 , all of the electrical components of the on-board power supply system 24 of the electric vehicle 20 downstream of that can be dimensioned with the simplest protection requirements.
[0044] Furthermore, the at least one surge arrester 111 of the protective device 110 can be designed to divert a voltage surge of up to 1.5 kV or of up to 3 kV or of up to 6 kV. The diversion can take place via a ground connection of the electric vehicle 20 or via a ground connection of the charging device 30 .
[0045] By way of example, a voltage of less than 1.5 kV is present owing to the diversion of the electric voltage surge when the electric voltage surge appears at the output 110 b of the protective device 110 . As a result, simple safety means for surge protection of the individual electrical components can advantageously be used in the on-board electrical power supply system.
[0046] By way of example, the surge arrester 111 of the protective device 110 is designed as a gas-filled surge arrester 111 or as a gas discharge tube or as a varistor or as a suppressor diode.
[0047] By way of example, components for protecting the inputs and outputs of electronic circuits against temporary voltage surge pulses or voltage transients, as occur as a result of switching processes in the grid or close lightning strikes, are used as suppressor diode, also referred to as transient absorption Zener diode (TAZ diode for short) or transient voltage suppressor diode (TVS diode for short).
[0048] By way of example, a gas-filled tube can be used as gas discharge tube, which gas-filled tube is used as surge arrester for protecting against voltage surge pulses; the voltage surge is reduced in the gas discharge tube by the automatic ignition of a gas discharge.
[0049] The interface device 115 of the surge protection device 100 can be configured to be coupled to at least one electrical consumer or to a plurality of electrical consumers of the on-board electrical power supply system 24 of the electric vehicle 20 and to protect the at least one coupled electrical consumer or the coupled electrical consumers of the on-board electrical power supply system 24 of the electric vehicle 20 against the electric voltage surge.
[0050] The electric vehicle 20 to be protected can be an electric vehicle or a hybrid motor vehicle or another motor vehicle which has an electrical energy store which can be charged during charging of the motor vehicle 20 from a charging device 30 designed as a stationary charging station as charging column.
[0051] By way of example, the charging device 30 is a device or an electrical installation which is used to recharge electric vehicles 20 driven by rechargeable batteries by simple insertion or plugging-in of a standard plug into a corresponding socket. The stationary charging device 30 may be configured as part of a charging station.
[0052] The stationary charging device 30 comprises, for example, a plug-in connector or a plug which is adapted to a socket or a female connector of the electric vehicle 20 .
[0053] FIG. 2 shows a schematic illustration of an electric vehicle having a surge protection device for protecting an on-board power supply system of an electric vehicle against an electric voltage surge according to another embodiment of the invention.
[0054] By way of example, an electric vehicle 20 comprises a surge protection device 100 for protecting an on-board power supply system 24 of an electric vehicle 20 . The electric vehicle 20 can be charged by means of a stationary charging device 30 in the form of a charging column.
[0055] The charging column can have a socket which is part of a domestic power supply 32 . The domestic power supply 32 can have lightning-protection means which allow electrical voltage surges of up to 6 kV. By way of example, an external lightning protector can be connected to the equipotential bonding of the building.
[0056] The surge protection device 100 connected upstream can be configured such that the at least one surge arrester 111 of the surge protection device 100 is designed such that a voltage of less than 1.5 kV is present owing to the diversion of the electric voltage surge when the electric voltage surge appears at the output 110 b of the protective device 110 .
[0057] As a result, the electrical components of the electric vehicle 20 are all protected together to a maximum occurring voltage surge of at most 1.5 kV.
[0058] The on-board electrical power supply system 24 of the electric vehicle 20 may have, for example, a DC transformer 25 , an intermediate circuit 26 , electric drive systems 27 , a 14-volt on-board power supply system 28 with an integrated DC transformer and an electrical air-conditioning processor circuit 29 as electrical components.
[0059] The other reference signs illustrated in FIG. 2 have already been explained in the description of the FIG. 1 and are therefore not described further.
[0060] FIG. 3 shows a schematic illustration of a flow chart of a method for protecting an on-board power supply system of an electric vehicle against an electric voltage surge according to another embodiment of the invention.
[0061] As a first method step of the method for protecting an on-board power supply system of an electric vehicle, an input device 105 of a surge protection device 100 of the electric vehicle 20 is coupled S 1 to a charging device 30 and a protective device 110 of the surge protection device 100 is coupled via an input 110 a of the protective device 110 to the input device 105 .
[0062] As a second method step of the method for protecting an on-board power supply system of an electric vehicle, a surge arrester 111 is provided S 2 in the protective device 110 for diverting a voltage surge.
[0063] As a third method step of the method for protecting an on-board power supply system of an electric vehicle, the output 110 b of the protective device 110 is coupled S 3 to the on-board power supply system 24 via an interface device 115 in order to protect the on-board power supply system 24 of the electric vehicle 20 against the electric voltage surge.
[0064] In this case, the method steps can be repeated in any sequence, iteratively or recursively.
[0065] Although the present invention was described above on the basis of preferred exemplary embodiments, it is not restricted thereto but can be modified in various ways. In particular, the invention can be changed or modified in multifarious ways without deviating from the core of the invention.
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The present invention relates to an overvoltage protection device ( 100 ) for protecting an onboard power system ( 24 ) of an electric vehicle ( 20 ) from electrical overvoltage, having: an input device ( 105 ) which is embodied as a power connection of the electric vehicle ( 20 ); a protection device ( 110 ) which is coupled at an input ( 110 a ) to the input device ( 105 ) and has at least one overvoltage diverter ( 111 ) for diverting an overvoltage; and an interface device ( 115 ) which is configured, through coupling of an output ( 110 b ) of the protection device ( 110 ) to the onboard power system ( 24 ), to protect the onboard power system ( 24 ) of the electric vehicle ( 20 ) from the electrical overvoltage.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present invention is related to commonly-assigned U.S. patent application Ser. No. 08/648,772 filed May 16, 1996 and entitled "Method of Forming an Organic Electroluminescent Display Panel" by Littman et al; commonly-assigned U.S. patent application Ser. No. 08/788,537, filed concurrently herewith, and entitled "Method of Depositing Organic Layers in Organic Light Emitting Devices" by Tang et al; commonly assigned U.S. patent application Ser. No. 08/788,532 filed concurrently herewith, and entitled "Method of Making Color Filter Arrays by Colorant Transfer and Etch" by L. C. Roberts; commonly-assigned U.S. patent application Ser. No. 08/788,108 filed concurrently herewith, and entitled "Method of Making Color Filter Arrays by Transferring Two or More Colorants Simultaneously" by Roberts et al; and commonly-assigned U.S. patent application Ser. No. 08/787,732, filed concurrently herewith, and entitled "Method of Making Color Filter Arrays by Colorant Transfer Using Chemical Mechanical Polishing" by Roberts et al, the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to methods of making color filter arrays which are particularly suitable for use on image sensors.
BACKGROUND OF THE INVENTION
In making color filter arrays, separate layers of different colors must be formed. Frequently these layers are formed using dye as the colorant material which is imbibed into dye receiving layers which must be of a controlled thickness, and a precise amount of dye must be used to achieve the appropriate color. See, for example, commonly assigned U.S. Pat. No. 4,764,670 to Pace et al and U.S. Pat. No. 4,876,167 to Snow et al which describe such a process. An additional problem associated with this process is that the dye receiving layers swell upon the introduction of dyes, limiting the smallest dimension which can be attainable for use over very small pixels. Another problem with this process is that dyes are susceptible to fading on exposure to light.
Color filter arrays may also be fabricated using evaporated colorants which do not involve any receiving polymer. In order to fabricate such color filter arrays over image sensors, a typical process is as follows: A photoresist layer is coated on a semiconductor substrate such as silicon which already has an array of light receiving sites referred to in the art as pixels or photo-sites formed in the substrate. Thereafter, the photoresist is patterned to form openings over the pixels or photo-sites. A colorant, generally an organic dye or pigment, is then deposited over the patterned photoresist layer and, of course, forms a layer of colorant in the openings over the adhesion promoting layer. A lift-off process is now performed and the patterned photoresist layer and the overlying colorant on the photoresist layer are removed from the image sensor. The lift-off solvent is selected so that it will dissolve or soften the photoresist layer without having any effect on the pigment. Alternatively, an ultrasonic bath technique is used. In this technique, the image sensor is immersed into a bath of a solvent and ultrasonic energy is applied to the bath to effectively remove the photoresist layer and the overlying colorant, leaving colorant over the selected pixels.
Turning to FIG. 1, which shows a method for making coatings from evaporated organic colorants. A substrate 102 is positioned adjacent to an aperture mask 104. The aperture mask provides an aperture over a portion of the substrate. An organic colorant which is to provide the coating is placed into a source boat 100, which is heated by passing an electric current through it. Alternatively, the boat may be heated by the application of radiant heating from a suitably placed heat source. Upon being heated under reduced pressure, the colorant vaporizes and travels from the source, impinging on mask 105. The portion of colorant vapor which passes through the opening in mask 105 travels along the lines 103, and between those lines, depositing on the substrate 102 and mask 104.
There are a number of problems associated with this technique which involves depositing layers in a partial vacuum and is frequently referred to in the art as physical vapor deposition (PVD). In certain cases, it is difficult to control the thickness and uniformity of the colorant disposed over the pixels. The process of vacuum deposition of the colorant typically requires the use of an appropriate placement of sources or masks or moving substrate fixtures to produce a coating which is uniform. However, the colorant material may deposit on the mask and vacuum fixtures to such a degree that it flakes off, creating undesirable contamination and waste of the colorant, and requiring frequent clean-up. In addition, the moving fixtures may generate undesirable particulate materials which may cause contamination of the substrate.
Some other problems in making color filter arrays by the PVD process are the need to use a large source-to-substrate spacing which requires large chambers and large pumps to reach a sufficient vacuum, and the need for masks which cause low-material utilization and build-up on the mask with the concomitant contamination problems. Very specific off-axis source location relative to the substrate, which is sometimes needed for uniform coating, causes very poor material utilization. Still further, source replenishment problems exist for coating multiple substrates in one pump-down. In addition, when multiple layers are deposited, the process needs to be carefully monitored for the thickness of layers in the multiple colorant coatings in multiple cycles.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved method for making color filter arrays which obviates the above difficulties, provides uniform colorant over the pixels, and provides low cost and high quality image sensors.
This object is achieved by a method of making a color filter array on a first substrate having an array of pixels, comprising the steps of:
a) depositing and patterning a photoresist layer on the substrate layer to form selected openings over pixels in the array;
b) providing a transferable colorant layer on a second substrate and positioning such transferable layer in transferable relationship with the first substrate;
c) transferring the colorant material to the photoresist layer on first substrate, and
d) removing the patterned photoresist layer leaving behind the colorant material in the position of the openings over the selected pixels.
ADVANTAGES
Advantages of this technique include the effective utilization of evaporant materials with high quality uniformity over large areas. Other advantages include precise control of layer thickness and lower maintenance of deposition vacuum chambers. In addition, the present invention provides an evaporative purification of the colorant during the preparation of the transferable colorant coating, and it requires minimal monitoring for the subsequent deposition process. Still further, it offers the ability to coat at higher pressures and in smaller vacuum chambers which permit faster cycle time and the use of lower-cost vacuum equipment than for standard PVD techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a typical configuration for conventional physical vapor deposition (PVD);
FIG. 2 shows a typical configuration for the thermal transfer of a material from an intermediate substrate to the final substrate, according to the present invention; and
FIGS. 3a-g show various steps in a method according to the present invention for making color filter arrays.
FIGS. 4a-4f show various steps in a method similar to that shown in FIGS. 3a-3g for making color filter arrays in accordance with the present invention.
It will be understood that the drawings are not to scale and have been shown for clarity of illustration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning first to FIG. 1, an arrangement for conventional PVD is shown, including a heated source 100, containing the material to be deposited, the substrate 102, and masks 104 and 105 which restrict the material vapor to paths 103 and the region in between.
In FIG. 2 is shown a configuration for the transfer of a material which has been deposited as a coating on the first substrate 200, onto the second substrate 201 as indicated by the arrows 205 and which is promoted by heating with heat sources 202 as indicated by radiant heat 203 acting through an aperture 204.
Turning next to FIG. 3a where a silicon substrate 300 is shown, the substrate has already been processed to provide wells for different dopant materials to form pixels 301. As is well understood to those skilled in the art, the substrate may be a composite of different layers. For a more complete description of the construction of image sensors, see commonly assigned U.S. Pat. No. 5,235,198.
As shown in FIG. 3b, an adhesion-promoting layer 302 is formed over the surface of the substrate 300 and the pixels 301. The adhesion-promoting layer can be formed by a number of techniques including spin-coating of an organic polymer or of a spin-on glass, or by chemical vapor deposition. The adhesion promoting layer may be patterned to form recesses in the adhesion promoting layer above the pixels. Alternatively, the adhesion-promoting layer may be applied after formation of the patterned photoresist layer 303.
As shown in FIG. 3c, a spin-coated photoresist layer is patterned to provide openings over the pixels 301. Such patterning techniques are well known to those skilled in the art. Typically, the photoresist layer can be imagewise exposed to light, illuminating particular areas of the layer. A development step is then used to form openings over the pixels 301 providing the desired pattern.
As shown in FIG. 3d, where a second substrate 304 is provided. (This substrate typically is stainless steel, but other substrate materials can be used which are heat resistant and flexible.) A layer 305 having a colorant is formed on the substrate 304. Typically, the colorant layer is formed by physical vapor deposition, which provides uniform layers of controlled thickness, containing no materials with higher volatility than the colorant. The layer 305 can be an organic colorant which is transferable upon the application of energy such as heat. In a preferred embodiment of the present invention, the colorant is vaporized by heating under reduced pressure, and condensed on a moving strip of stainless steel foil which is passed over the heated source at a constant rate.
In FIG. 3e, the substrate 304 and colorant layer is shown positioned relative to the substrate 300 and the pixels 301 in the substrate. In the process it is desired to transfer the colorant layer 305 onto the substrate and the pixels. As shown in FIG. 3f, the transferred colorant layer is now labeled number 306. In order to provide this transfer, heat is applied to the substrate 304. Typically, the substrate is composed of metals, such as steel or aluminum or of a temperature-resistant plastic such as a polyimide film. Heating is often done by exposing the non-coated side of the substrate 304 to electromagnetic radiation of wavelengths which are absorbed by the substrate or by the colorant coating and are converted into heat by radiationless decay processes. The electromagnetic radiation may be applied over a large area simultaneously as from an extended lamp source, or it may be applied as a scanned beam as with a laser. It is appreciated that imagewise light exposure may be used to heat and transfer only a portion of the colorant coating. Another method used to heat substrate 304 in order to transfer the colorant 305 is to pass an electric current through the substrate, particularly when the substrate used is composed entirely or partially of metal. In still another method, the substrate may be heated by direct contact with an object such as a metal block, a high temperature roller, or other such devices which can be heated or pre-heated to the required temperature and which can transfer heat to the substrate by direct thermal contact. Typical distances and pressures for the transfer of colorant are from about 0.1 mm to about 3 mm at pressures of less than or equal to about 0.1 Torr, up to a distance of about 50 mm at pressures of less than 0.001 Torr.
FIG. 3g shows the color filter array after a lift-off process. The lift-off process is needed to remove unwanted portions of the photoresist layer 303 and the portions of the layer 306 on the unwanted portions of the photoresist layer 303, leaving behind colorant layers 307 over the selected pixels.
More particularly, the lift-off process is as follows:
A photoresist layer is patterned by imagewise exposure to electromagnetic radiation of the appropriate wavelength followed by development to open up areas where a subsequently deposited layer is desired. The subsequent layer is deposited on both the opened areas and the remaining photoresist, followed by the lift-off, in which the photoresist is dissolved or swollen in a solvent, causing it to become detached from the underlying substrate, lifting-off to leave the desired deposit in place. A description of the lift-off process and typical materials used is given in chapter 12 of Semiconductor Lithography, by W. M. Moreau, Plenum Press, N.Y., 1989.
In order to make a color filter array with a plurality of colors, the above steps need to be repeated for each new colorant layer that is deposited over pixels.
Turning to FIG. 4a where a silicon substrate 400 is shown, the substrate has already been processed to provide wells for different dopant materials to form pixels 401. As is well understood to those skilled in the art, the term substrate includes a composite of different layers.
As shown in FIG. 4b, an adhesion promoting layer 402 which can be subsequently etched is formed on the substrate 400 and the pixels 401, and a layer of photoresist 403 is formed above it.
As shown in FIG. 4c, the photoresist is exposed and developed to form openings over selected pixels, leaving photoresist 404 over the rest of the layer 402.
As shown in FIG. 4d, the openings in the patterned resist layer 404 are used as a mask for an etch of the underlying layer, to produce a pattern of recesses in the underlying layer, now numbered 405.
As shown in FIG. 4e, a colorant layer is deposited on the patterned resist layer 404 and the recesses in underlying layer 405 to give layer 406/407.
As shown in FIG. 4f, the colorant which is not above the selected pixels 406 and the patterned photoresist layer 404 is removed by a lift off process, to leave the patterned layer 405 and the colorant above the selected pixels, 407.
In order to make a three-color color filter array, the above steps need to be repeated for each new colorant layer that is deposited over subsequently selected pixels. In an alternate embodiment of the present invention a second photoresist layer can be deposited and patterned on the adhesion promoting layer.
Colorants which are useful in the processes shown in FIGS. 3a-g, 4a-4f include the following: phthalocyanines, such as Pigment Blue 15, nickel phthalocyanine, chloroaluminum phthalocyanine, hydroxy aluminum phthalocyanine, vanadyl phthalocyanine, titanyl phthalocyanine, and titanyl tetrafluorophthalocyanine; isoindolinones, such as Pigment Yellow 110 and Pigment Yellow 173; isoindolines, such as Pigment Yellow 139 and Pigment Yellow 185; benzimidazolones, such as Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 175, Pigment Yellow 194, Pigment Orange 36, Pigment Orange 62, Pigment Red 175, and Pigment Red 208; quinophthalones, such as Pigment Yellow 138; quinacridones, such as Pigment Red 122, Pigment Red 202, and Pigment Violet 19; perylenes, such as Pigment Red 123, Pigment Red 149, Pigment 179, Pigment Red 224, and Pigment Violet 29; dioxazines, such as Pigment Violet 23; thioindigos, such as Pigment Red 88, and Pigment Violet 38; epindolidiones, such as 2,8-difluoroepindolidione; anthanthrones, such as Pigment Red 168; isoviolanthrones, such as isoviolanthrone; indanthrones, such as Pigment Blue 60; imidazobenzimidazolones, such as Pigment Yellow 192; pyrazoloquinazolones, such as Pigment Orange 67; diketopyrrolopyrroles, such as Pigment Red 254, Irgazin DPP RubinTR, Cromophtal DPP OrangeTR; Chromophtal DPP Flame Red FP (all of Ciba-Geigy); and bisaminoanthrones, such as Pigment Red 177.
EXAMPLES
In accordance with the above-stated invention, the following has been performed.
Example 1
Commercially obtained copper phthalocyanine was heated by passing electrical current through the tantalum boat which contained it, while maintaining a reduced pressure of approximately 6×10-5 Torr in a vacuum bell jar. About 0.2 microns of phthalocyanine were deposited onto a section of stainless steel foil, having a thickness of about 25 microns. The coated foil was then mounted about 3 mm distant from a silicon wafer which had been spin-coated with about 1 micron of poly(methyl glutarimide), "PMGI" from Microelectronics Chemical Corp., and then coated with about 1.3 microns of photoresist AZ5214IR (Hoechst Celanese Corp.) which was subsequently patterned and developed, and the non-coated side of the foil was positioned about 25 mm from an array of heat lamps (General Electric, Part no. QH500T3/CL) spaced about 30 mm apart. The assembly was subjected to a vacuum of about 6×10E-5 Torr and the heat lamps were powered for 60 seconds to transfer the phthalocyanine to the silicon wafer. The water was removed from the vacuum chamber and subjected to ultrasound in a tray of acetone for 90 seconds, using a Branson Model 3200 ultrasonic bath. The photoresist was completely removed by this treatment, leaving intact the copper phthalocyanine features in the desired pattern.
Example 2
Commercially obtained copper phthalocyanine was heated by passing electrical current through the tantalum boat which contained it, while maintaining a reduced pressure of about 6×10E-5 Torr in a vacuum bell jar. About 0.2 microns of phthalocyanine were deposited onto a section of stainless steel foil, having a thickness of about 25 microns. The coated foil was then mounted about 3 mm distant from a glass substrate, and the foil was clamped between two electrodes. The assembly was subjected to a vacuum of about 0.1 Torr, and electric current was passed through the foil (at 30 volts) for about 10 sec., causing the ends of the foil to reach a temperature of about 260 degrees C. and the phthalocyanine to transfer to the glass substrate.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
PARTS LIST
1a silicon substrate
1b pixels
3 photoresist
12 chapter
100 source boat
102 substrate
103 lines
104 mask
105 mask
200 substrate
201 substrate
202 sources
203 heat
204 aperture
205 arrows
300 substrate
301 pixels
302 layer
303 photoresist layer
304 substrate
305 layer
306 colorant layer
307 colorant layers
400 substrate
401 pixels
402 layer
404 photoresist
405 layer
406 pixels
407 pixels
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A method of making a color filter array on a first substrate having an array of pixels is disclosed. The method includes depositing and patterning a photoresist layer on the substrate layer to form selected openings over pixels in the array; providing a colorant layer having a transferable colorant material on a second substrate and positioning the second substrate such that the transferable colorant material is in transferable relationship with the first substrate; transferring the colorant material to the photoresist layer on the first substrate; and removing the patterned photoresist layer leaving behind the colorant material in the position of the openings over the selected pixels.
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This application claims the benefit of provisional application No. 60/129,769, filed Apr. 15, 1999.
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a system and method which is particularly adapted for people and families who have elected a home based educational program, and more particularly to such a system and method which provides active connecting links between the established educational institutions (such as school districts) and those who have elected not to have their children attend (or being involved with) the established educational institution, but would rather do “home schooling.”
b) Background Information
The tradition of home education has been with us for millenniums. It began with the family or family units teaching their offspring the basic knowledge and skills for survival and accomplishing their day to day chores. History records that the concept of formal education took root about 3000 BC when the Sumarians (who lived in the Tigris/Euphrates valley) and the Egyptians each invented a writing system. This made possible the beginning of schools as we know them today. The schools which were established in Egypt were for the very few.
Probably the most significant educational advances in early Western History were made in Greece (particularly in Athens) from about 700 BC to about 300 BC. One of the luminaries (Socrates) who taught in Greece and employed an informal method of education which has been come to be known as “Peripatetic Method.” The term “peripatetic” means “walking about place to place; traveling on foot,” and Aristotle conducted his discussions by walking about in the Lyceum of ancient Athens. After being condemned to death in 399 BC for impiety and corrupting the young men of Athens (a little over 70 years of age), his basic teachings were carried on by Plato and then Aristotle.
During that time, Athenian education made substantial advances, but for early education, rather than establish a school, a trusted family slave took the students from teacher to teacher, each who specialized in a certain subject or related subjects. This continued until they were about fifteen years of age, and from ages sixteen to twenty they attended a government sponsored “gymnasium” where they were trained to be citizen/soldiers.
By the year 300 BC Greece became the acknowledged center of culture and education and many of the early Romans would send their children to Greece for education. As Rome became dominant from between 100 BC and 100 AD, Roman education flourished. After the fall of Rome and during the Middle Ages up until about 1500 in Western civilization the education was accomplished primarily by the Christian clergy.
Probably the greatest catalyst for education was Gutenberg's invention of movable type which made the modern printing press possible. This enabled books to be printed in large quantities which made formal education available for a large number of people.
By the late 1700's, in Europe there was a more of a nationalistic trend in education, and much the responsibility for education was transferred from the clergy. A number of European countries (Great Britain being an exception) adopted state controlled educational systems.
In the United States, shortly after the Revolutionary War, there was also a growing concern that public education should be provided. One of the main objectives was to give Americans common goals and a sense of national unity. In the 1800's, there was debate in the U.S. as to whether public funds could be used to support secondary schools. In a landmark decision of 1874, the Michigan Supreme Court settled the issue to legalize the practice that public funds could be used to support secondary education.
As we moved into the twentieth century, the concept of publicly funded schooling had become well entrenched in our education system. In the first half of the twentieth century, public education was almost entirely in the domain of the individual states. Subsequent to World War II, however, the federal government began taking a more active role. One of the major reasons was the funding of the GI bill and also enlarging the educational opportunities of veterans. In 1965 the elementary and secondary education act was passed by the U.S. congress, to furnish school districts with funds to help education children from low income families. In more recent years, the federal government has become more active and adopted certain standards and quite often federal funding for education is contingent on adopting “and adhering to” certain standards.
For some time now, rather than an elementary education up to a certain grade level being considered a “benefit” that should be provided for children, it has now become a requirement. As indicated above, some aspects of state funded education is controlled by the Federal government by setting certain standards, but much of the detailed planning for a basic curricula is done at the state and local level. Thus, while there are many options in the course of obtaining a basic education, there are requirements that certain basics be taught.
In recent years, particularly in the last decade or two, there have developed different views about what children should be taught and how they should be taught, and also who is ultimately responsible for the task. Thus, there has developed a growing number of families nationwide (approaching ten percent of the general population) who choose to educate their children at home (home schoolers). Over the past ten years, there has developed a philosophical and tolerance gap between two groups, namely:
a) those who support the traditional K-12 public school system as we know it, varying little from state to state throughout the nation;
b) the growing number of people who chose to educate their children at home.
Each group can point to myriad of successes and failures, claim to offer a far better prospective success than the other. The home schoolers can point to such things that the public schools face more and more incidents of violence, poor performance of students and nationwide teacher shortages. On the other hand, the teaching profession can take justifiable pride in its skill and accomplishments.
Accordingly, it is a major object of the present invention to provide a cooperative system and methods by which the established educational institutions can work cooperatively with the “home schoolers” to enhance the educational opportunities of the children who are in home schooling situations and to accomplish this in such a way as to meet the needs of all those involved. To state this another way, this system of the present invention is to “blend” or “connect” these two now separate systems and to accomplish the goals of each in a way that preserves the educational benefits provided by each system separately.
SUMMARY OF THE INVENTION
The system of the present of the present invention provides education needs for home schooling, where there exists:
a) a School District which operates at least one school, with students enrolled in, and attending class in, the school;
b) a plurality of Home School Units, each Home School Unit comprising at least one parent and one student who is being home schooled by the parent.
The system incorporates with the School District and with the Home School Units, a Home School Program Center to accomplish various functions. Basic functions relating to the Home School Program Center and the Home School Units include the following:
i. accomplishing enrollment of students of the Home School Units in the School District;
ii. the Home School Program Center maintaining school records of classes completed and credits earned to qualify the students of the home school units with full accreditation and credit for the classes completed and also as having graduated from the school district if such students have met the requirements of the School District for graduation;
iii. establishing individual learning programs for students;
iv. the Home School Program Center providing the basic equipment and materials (e.g. text, curricular materials, computers and other communication equipment along with other equipment as needed); and
v. the Home School Program Center and the Home School Units accomplishing the proper testing at the benchmark points so that the courses taken by the student are properly certified by the School District.
Further, the Home School Program Center accomplishes certain functions with the School District, namely:
i. coordination in initially enrolling the students and following tasks in maintaining the enrollment;
ii. coordination and maintaining all the necessary records for that student and taking care of all other procedural matters and giving proper accreditation for all classes completed and graduating the students with the proper credits and credentials;
iii. coordination in providing educational services, equipment and materials as requested from the Home School Program Center for the Home School Units.
In addition to the functions relating to the Home School Program Center and the Home School Units, as indicated above, in a preferred form the system comprises one or more functions selected from the following group, namely:
i. initial contact between the home school units and the home school program center;
ii. continuing periodic communications between an assigned certified teacher and the home school units, as reasonably required by the ILP of each unit;
iii. counseling services by the way of problem solving, trouble shooting, and meeting special needs, provided for the home school units;
iv. providing additional educational help, programs and material as needed to accomplish the ILP of each home schooling unit (either from the school district or other private resources);
v. monitoring progress of various individual learning programs of the various students.
The system further comprises one or more Field Representatives for the Home School Units. This Field Representative would desirably be a person (or persons if more than one representative) having a reasonable balance of skill and/or experience in home schooling to coordinate with the Home School Units and the Home School Program to facilitate home schooling.
Also, in the preferred embodiment of the system, there are one or more parent advisory groups, made up from the Home School Units which meet to discuss goals, problems, possible improvements, and/or other matters relevant to activities of the Home School Units and the Home School Program Center.
In the Method of the present invention, there is established a cooperative program to enhance home schooling where there is an existing School District, and also a plurality of Home School Units, as described above. This program is accomplished by following the steps which are recited above as functions of the system. These and other features of the present invention will be described more fully in the following text.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view illustrating the existing system by which home schooling is accomplished; and
FIG. 2 is a schematic view illustrating the system and method of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A. Introduction
It is believed that a clearer understanding of the system and methods of the present invention, as well as the novel features thereof, will be obtained by first describing the present system that in large part exists throughout the United States (and possibly also in other parts of the world).
B. The Present System in the U.S. Relative to Home Schoolers
To describe the present situation in the United States, reference is first made to FIG. 1 . The responsibility for publicly funded education falls primarily upon each state government. However, as indicated earlier in this text, in the last half century there has been increased government funding from the federal government for public education, and also the increased influence of the federal government. For example, a significant part of the funding of the federal government is contingent upon the various state governments adopting minimum requirements or standards for secondary education and also requirements that these be met.
Then the state government in turn sets more specific standards, establishes certain minimum curricula requirements, etc. Generally, responsibilities of secondary education in the various states is placed up into school districts, which operate essentially independently from one another, except for the control that is imposed by the state government. Most school districts are funded by some form of student “count” or attendance.
A school district in some respects operates as a business, in that it faces the usual business burdens of paying for the fixed overhead, as well as the variable expenses. Since each school district is obligated to provide basic education for the students that are in the district, the school must project population increases (or decreases) and plan accordingly, (e.g. school buildings, bus transportation, etc.). Thus, school planning is something of a balancing act. If it underestimates the student population growth that is expected for the next five or ten years, there is overcrowding, and emergency measures need to be taken to accommodate this overflow and meet basic educational needs. On the other hand, growth of student population is overestimated, with fixed overhead diminishing little or not at all, the school has to “tighten it's belt,” possibly cut programs, etc. Accordingly, in terms of economic planning, a significant movement toward home schooling (and thus loss per student of funding in the school district) can create difficulties, and the school district would generally feel (and quite justifiably feel) that this would adversely affect the quality of education provided by the school district.
Another factor is that probably in most instances, when parents withdraw their children from attending the public schools in the district, they do so because they are dissatisfied with the education which is being provided in the school district. Or at least the parents that “home school” their children have very different ideas as to what the children should be taught. This can account to some extent for the “gap” between the home schoolers and the school district.
Another factor is that when parents do home school their children, the state in some instances imposes certain standards. However, generally, the standards of what occurs on a day to day basis, (or even a month to month basis) of home schooling are either non-existent or are not strictly adhered to. However, to maintain the right to home school in some states, the student that is home schooled would be tested periodically to see if the home schooling has been carried out in a manner to meet minimum standards. This situation is indicated by the broken line shown in FIG. 1 connecting the state 10 with the home schooler.
To now look at this situation graphically, reference is again made to FIG. 1 . The state government, which is indicated at 10 , (influenced and to some extent controlled by the federal government which is indicated at 12 ) provides the funding and basic control of the various school districts. In many respects, each school district is autonomous in that it can elect its own school board, select the employees it hires, set curriculum within the guide lines set by the state, and in general make many decisions locally.
In FIG. 1, the school district, indicated at 14 , has been shown being located on one side of the state government, and the home schoolers, indicated at 16 , on the other. In large part, there is substantially little, if any, direct contact between the home schoolers and the school district. Also, as shown in FIG. 1 is a broad category of other educational resources, indicated generally at 18 , in which are three groups of business entities and people in the private sector. Namely (a) educational texts and curriculum materials 20 and educational equipment and supplies 22 , and (b) educational programs and services 24 .
In theory, since the providers of these various products and services are in the private sector and would be pleased to sell to most all types of purchasers, including home schoolers, as a practical matter there is a gap in this line of communication. The advertising and other sales efforts of these various private companies (and individuals) is directed more toward the established school districts, and the home schoolers are less informed of not only the existence of these, but also are not in the position to evaluate the quality in any depth.
Let us summarize our present educational system and how the home schoolers fit in. This can be summarized as follows:
a) The federal government influences the state government relative to education by providing funding and broad guidelines and standards, the implementation of which may or may not be connected to some or all of this funding.
b) The state government provides for school districts. Standards which are more specific than those provided by the federal government, provides funding, and sets basic rules by which the school districts must operate.
c) The state government has very little to do with the home schoolers, except to provide a minimum amount of control on an infrequent basis simply by checking whether or not the home school student is obtaining an adequate education.
d) In general, the school district is in large part “disconnected” from those students in the district who are home schooled.
e) The private sector which provides products and services for education would have continuing (those who provide education texts, educational equipment and supplies, and educational programs and services) have contacts with the established school districts, but as a matter of practical business operation, less contact with individual home schoolers.
f) Yet the home schoolers have in large part separated themselves from the “establishment” in their school district and when educational resources are needed, they are left to their own resources and /or others.
C) Overview of the System of the Present Invention.
The spirit of the system and methods of the present invention can probably best be expressed in the words of its originator, Mr. Pocock, who states that this system was initiated to
“. . . provide resources and support to parents who have elected to educate their children in their home. The objective is to build and foster a community of learners who views education as not confined to the traditional four walls of a classroom, but rather a free flowing exchange of knowledge and ideas world wide through technology. This system brings a fresh approach of mutual trust among parents and schools by honoring parental choice in curricula materials and instructional methodology based upon the needs of each and every individual child.”
“Perhaps the most significant component of this mission statement is the reference made to instilling trust between parent and public schools. The evidence of this trust is the fact that parents are allowed to choose both the content of curricula materials and the methodology to be employed in the delivery of that content in the teaching of their children, so long as minimal standards are met at a level equivalent, or above, regular classroom students in a particular district. It is this concept of choice that is the most singularly and most unique concept of this system.”
With the foregoing being given as background information, let us now turn our attention to FIG. 2, which is a schematic representation of the system of the present invention, indicated generally at 30 .
In viewing the main components of the new system, as displayed in FIG. 2, and comparing this with the prior art system in FIG. 1, one item becomes particularly evident. It will be noted that the block in FIG. 1 representing the state government at 10 has, in the new system shown in FIG. 2, been taken out of the central position, and has been moved to another location in FIG. 2 where it still has its direct link to the School District 12 . In the central location in the new system of FIG. 2, there has been positioned a service center for home school units, this being called an “HSP Center” (i.e. a “Home School Program Center”).
The functions of this HSP Center 32 will be discussed in more detail later in this text, but for the present, it can be described as being made up of one or more teachers who work with the home schooling program and an administrative person or staff which handles various clerical matters, providing equipment and services for the home schoolers, and other administrative needs. Further, this HSP Center 32 is a communication center where it gathers the information necessary for the operation of the home schooler program, receives information from the home schoolers and others involved in the program, coordinates this program properly and also takes proper action in accordance with the needs indicated by such communications.
At this point, let us now pause and look at these communication links. First (and very important), this HSP Center 32 has a direct operating link with the School District. Further, the HSP Center 32 has a direct link to the people and entities that provide the educational texts, equipment and supplies, and also to the entities and individuals who provide the educational programs and services.
Then this HSP Center 32 has these very important direct links with the home schoolers individually. Further, there is a direct link to the Field Representatives, indicated at 34 , and a direct link to the Home Schooler advisory Group or groups designated 36 . Now lets look at the effect of these links or connections.
With regard to the status of the home schoolers, the students that are being home schooled are actually enrolled as students in the School District. While the policy in the various state may differ as to financing of a school district relative to students, in the very large number of states where the money given to the school district depends upon the students enrolled. Further, the educational resources of the school district are fully available to these home schoolers who are now students registered as students in the school district.
Also, the Home School Program Center 32 (HPS Center) has links to the other Educational Resources 18 so that these can also be made available in an efficient manner to these home school students. Yet, the objectives of the parents and students in the home school programs still have substantially the same degree of freedom that they had previously in terms of the choice and content of curricula materials, methodologies to employ, etc.
D) The Main Components of the System of the Present Invention
Let us now examine each specific component of this program. With regard to terminology, the term “student,” as it would apply to any one household shall be meant to include not only an individual student but also the two or more students in that household. Also, the term “parents” will be used to denote either two parents (if that is the situation), a single parent, or a guardian or other person who is responsible for that student. The parents and the student of a family or household will be designated by the term “Home School Unit”.
The term “School District” is to be used in a broader sense to designate an educational entity, whether or not designated a “School District” in accordance with practice of any particular state in the United States or elsewhere, where education is provided to the students through one or more schools where education is given in large part in a classroom environment.
Also, for convenience, when any person is referred to by a pronoun (e.g. he, she, his, her, etc.) this will be presented in the masculine gender, with the understanding that this includes both genders.
1. The Initial Contact and the Assessment.
The first step is that the parents and student are contacted by the HSP representatives and the entire program explained to both the parents and the student (i.e. the “Home School Unit”).
At that same time or at a later time, a teacher or other representative of the program would have made an initial assessment of the situation and identified the reasonable needs of the student and the parents.
For example, one of the parents might already have been a teacher and be fully qualified and willing to handle all the teaching requirements herself (or himself). In other instances, the parents may be able to handle certain courses, such as history, but may not feel at all qualified to handle math courses, English grammar, English composition, science courses, etc. Another situation is that while the parent may have capabilities in some or all of the academic areas to be handled, the work schedule of that parent may not fit in with the needs of the student.
Another situation is that the student himself may have individual needs. These needs may be met possibly by specialized equipment or certain additional and/or special programs. For example, in the category of educational programs and resources, indicated by the block at 22 , there in the private sector a wide variety of programs on different academic subjects. For example, the parent may want to teach mathematics, but may feel weak in that area. There are video programs which explain the teaching techniques for mathematics and actually explain this in a teaching environment, such as a teacher writing the problems on a chalkboard and leading the student through these. It is often difficult and time consuming for the home schooling parent to seek out these various programs and teaching aids. However, personnel at the school district (and presumably at the HSP Center) have access to (and likely already acquired familiarity with) these and would also have knowledge of (or at least be able to obtain the information about) which of these programs would be suitable for that situation.
So in the following discussion, it will be assumed that this assessment has been completed and that the parents, the student, and the program representative are fairly well settled on the type of program that would fit this student. Obviously, as time goes on, adjustments to this program may need to be made. The manner in which these adjustments are made will be discussed later in this text.
Let us now consider other components of the program.
2. Instructional Material and Equipment for the Home School Units.
All of the texts and other instructional material and equipment for the student is supplied by the Home School Program Center without any charge.
Each student will be provided with a computer, and e-mail. Also, the student would be provided with a telefax. However, if other communication equipment is available over the Internet or other electronic media that would take the place of the telefax, that could be used instead.
While the computer is an important element, it is believed that its role should not be overemphasized. The computer will not take the place of the parents and their efforts to guide and teach their children. In fact, it is believed that in some instances the importance of the computers is dangerously overestimated in the role that they should play in a child's formative years of education. With that being said, however, no one can question that the computer can greatly facilitate certain aspects of a child's learning, and there is significant research to support the importance of the computer in certain areas of the curricula, such as writing, because of the ease at which the students may edit their work. In addition, as part of the program there could be on-line course to offer to the student if the parents choose that option. For example, many courses are being offered on the Internet, and many educational courses on the Internet are interactive.
Possibly the greatest use of the computer in families enrolled in the program is to link the families together as well as to the HSP Center and Field Offices via e-mail. Parents may compare notes, have questions answered by certified teachers of the HSP Center, order curricular material and keep up with any deadlines, testing and other important items they should know. This is a very efficient, inexpensive way for the school district to keep in touch with enrolled families.
3. The Role of the Certified Teacher.
The term “Certified Teacher” denotes a teacher who is qualified as a teacher in the School District and has the “credentials” to function in the capacity as a “teacher” for this program. In some states, there is a certain ratio of how many courses or students that can be “taught” by that teacher in a correspondence course, independent study or distance delivery program. For those home school situations where the parent is actively going to be tutoring the student on a regular basis, that parent is the “teacher” in terms of performing the necessary tasks to accomplish the students education. In that case, the active role of the certified teacher would be minimal. Yet the certified teacher would be available for “trouble shooting”, problem solving, seeking out additional aides for home schooling parent, etc. In other instances, the teacher may be taking a more active role.
4. The Field Representatives.
A Field Representative is an experienced, successful home schooling parent who is familiar with “what works in home schooling” and who is willing to share their experience with other “less seasoned” parents just trying home schooling for the first time. The Field Representatives could be part time representatives and they could work out of their home. In fact, the Field Representative may be an active home schooling parent who is willing to help others on a part time basis. It is expected that the Field Representative would work in her or his own home, mostly over the telephone or via e-mail, answering hundreds of questions about everything from curricula to policy about the program. They would have the credibility among the home shcoolers that the Certified Teachers may not have because they are “one of them.” These Field Representatives can play an important role in building trust among the home schooling parents.
5. The Individual Learning Plan.
It was indicated earlier herein that at the time of the initial contact and interviews with the home schooling parent and student is conducted, decisions are made regarding the learning plan for that student. The concept of placing each and every child on her or his own learning course is actually an adaptation of a special education concept of the “individual education plan.” For students with special needs, the individual education plan is literally a complete directive to a school regarding what and how each specific child is to be taught.
It is presently connotated that the parents themselves submit the Individual Learning Plan for the student or each of their student children. In it, the parents address learning goals and objectives in each content area for the school year. Experience has taught that parents appreciate being requested to do this, because it adds a new dimension of planning to their instruction, and provides an objective means by which the progress of each child can be monitored.
This is a critical and delicate part of the relationship between the home schooling parent (s) and the certified teacher. It is necessary that the teachers make certain that the Individual Learning Plan contains learning objectives that are age appropriate for the child, yet while doing that not intimidate the parent (s) and removing the all important element of choice by the parents (and the student).
At the end of certain time periods of the year, the certified teachers are required to inquire about the progress each child is making on her or his Individual Learning Plan. At those times if the teacher and parent agree, adjustments may be made as necessary to the ILP.
6. Parent Advisory Committees.
When an adequate number of “first families” are enrolled in the program, each region would have a volunteer committee made up of parents who would make recommendations to the personnel at the program center concerning policies and procedures of the programs and ways in which there could be improvement. The Parent Advisory Committee (s) can make extremely valuable contributions, but is not empowered to perform or conduct any of the tasks which are assigned to the personnel at the HSP Center. Each Parent Advisory Committee would normally attempt to meet once a month during the school year. For example, the membership of each committee member could range between seven and thirteen members. A representative form the HSP Center could possibly present at such committee meetings. The Parent Advisory Committee are advisory and do have discretionary of a school board.
7. Special Education.
This program would be directly connected with the School District itself. Accordingly it does not attempt in any way to “skirt around” special education codes and statutes. Rather, this program puts the individual needs of each and every student first, before anything else, and this certainly includes those students with special needs. Present analysis of the program which has been conducted thus far indicates that many students with special needs may be better served by not participating in this home schooling program and be in a more traditional classroom environment. There can be various reasons for this. One is that children of special needs are often in need of opportunities to socialize with other students, and may not benefit from an educational environment which closes them off to such contacts. Also, even though the student may not have special needs relative to obtaining the educational goals, the personality, character, and general make-up of the student may be such that the home schooling environment facilitated by this program would not meet the needs of the student as well as the traditional classroom environment.
8. Learning Programs for the Home Schooling Parent.
Home schooling parents, just like other teachers, can benefit from frequent quality workshops covering a wide range of subjects. Such works can be of substantial benefit because they have a quite positive effect on home teaching. Such workshops could cover the teaching of reading, mathematics, creative writing, home economics, and science. Present analysis indicates that these are of substantial help, and that these could be offered to the home schooling parents at no charge.
9. Accountability (Standardized Testing).
Virtually every state requires that at certain points, each student enrolled in a public school be tested on her or his extent of mastery of basic academic skills. Typically, such tests are administered at “benchmark points,” such as first, fourth, eighth, and eleventh grades. The program parents would be thoroughly informed at the time of enrollment that the students are required to participate in such testing. It may be that a state does not require such testing for charter schools, correspondence schools, or independent programs. Nevertheless, present analysis indicates that such testing should be required for those who participate in the program.
It should be noted that many educators oppose standardized testing because of increasing pressure to raise scores and a growing tendency to “teach to the test.” Some would view a charter school as an opportunity to break away of such testing, thereby teaching “higher level thinking,” or areas of the curriculum that are more “exciting” or “challenging” to students. However, while there may well be validity to that view, the implementation of the present program is predicated on the thinking that if basic skills, such as reading comprehension and math computation are never tested, there is a good chance they will never be taught.
In the implementation of the present program, it is contemplated that standardized tests in controlled, secured conditions would be conducted each year as a minimum to whatever grades the state involved require such testing. It does so in testing centers (usually to field offices) that requires parents to bring students to the centers at the appropriate times.
In some teaching districts which cover a large geographical area, if there are hardships in the students coming to the program center for testing, accommodations could be made in this regard. The data presently available indicate that on the average, home school children score higher than their classroom counterparts. Thus, it is contemplated that in this program, testing is a very positive factor upon the acceptance of the program by the education community.
10. The Home Schooling Program Center (HSP Center).
The more detailed discussion of the program center has been postponed until the end of this text, mainly because many of the functions which are performed by the program center become evident when the various components of the entire program are described.
Nevertheless, it would be prudent to summarize these various functions. The HSP Center does not necessarily have to be a “center” in a geographical sense, even though it may well have advantages to have the personnel directly involved in the program be at one location. Rather, it is a “center” in terms of its functional characteristics. This HSP Center can be compared to the central processing unit of a computer where it transmits request and data to the various entities to which it is connected, receives inputs and requests from the same entities, and then coordinates these into a properly functioning network.
However, even though the efficient and timely performance of these various functions is extremely important to the program there is another very vital “human” ingredient that must be added.
For this program to succeed, it has to be imbued with an attitude, dedication and optimism to make the program succeed. Further, returning to the earlier quotations from Mr. Pocock, the originator of this system, we have to recognize the importance of the concept which he stated in the following words:
“Perhaps the most significant component of this mission statement is the reference made to instilling trust between the parent and the public schools. The evidence of this trust is the fact that the parents are allowed to choose both the contents of curricula materials and the methodology to be employed in the delivery of that content and the teaching of the children . . .”
It has to be recognized that parents have already made a decision that they are going to take over the primary responsibility for teaching their children. This program is to bring them together with the School District so that the goals of these parents and the students are enhanced further by the cooperation with the School District. Thus, the most critical human relationships in this program are those between the personnel of the HSP Center and the parents and students of the Home School Units, and also with the Field Representatives and also the Parent Advisory Committees.
With the foregoing in mind, now let us summarize the main functions of the HSP Center in cooperation with the Home School Units. These are as follows:
i) The initial contact with the parents and students and explaining the program to them.
ii) Accomplishing enrollment of the students in the program.
iii) Maintaining student records, including cumulative folders for grades K-8 and for grades 9-12 Carnegie credits earned and also including any dual college credits earned, also (when requested to do so) supplying such records to other School Districts, and requesting records from schools previously attended by the students.
iv) Establishing the Individual Learning Programs for the students (ILP's).
v) Providing the basic equipment (computers and other communication equipment along with other equipment as needed).
vi) Continuing the periodic communications between the assigned Certified Teacher and the Home Schooling Units, as reasonably required by the ILP of each unit.
vii) Counseling services in the way of problem solving, trouble shooting, and meeting special needs.
viii) Providing additional educational helps, programs, or material as needed to accomplish the ILP of each Home Schooling Unit (either from the School District, or other private resources, etc.).
ix) Monitoring progress of the various Individual Learning Programs of the various students.
x) Accomplish the proper testing at the benchmark points so that the courses taken by the student were properly certified by the School District.
xi) Throughout the program coordinating with the Field Representatives and the parent advisory groups to attend to various matters (major and minor) that might arise.
To again make the comparison with the HSP Center and a computer network, the whole system is “driven” by assessing the educational needs and related needs of the students, initiating programs to meet these needs (ILP's), and then bringing the educational, material and human resources into play to make the implementation of the ILP for each student successful. This is the starting point, and the main communication link is between the HSP Center and the Home Schooling Units. Then (again to use the analogy of the computer network) the requests and information transmitted and received to the other involved entities are in response to the needs of the HSP Center to in turn meet the needs of the Home School Units.
Thus, in addition to the eleven functions which were listed earlier herein that are accomplished between the HSP Center and the Home School Units, then there follows the functions which the HSP Center performs relative to the other entities of the system illustrated in FIG. 2 . These are as follows:
a) Coordinating with the School District and initially enrolling the students and follow up task and maintaining the enrollment.
b) Coordinating with the School District and maintaining all the necessary records for that student and taking care of all other procedural matters in properly graduating the students with the proper credits and credentials.
c) Providing educational services, equipment and materials, as requested from the HSP Center for the Home School Units.
Coordinating through the School District with the state and federal government authorities to ensure compliance with the rules which would affect the Home School Units.
Further, the HSP Center would coordinate with the other educational resources indicated in the lower part of FIG. 2 . This would entail ascertaining the needs of the various Home School Units, and then obtaining texts, materials, equipment, supplies, programs and other services as needed to meet the needs of the Home School Units.
It is to be understood that various modifications, additions, improvements, etc. could be made to the systems and methods of the present invention without departing from the basic concepts thereof. Also it is to be understood that while preferred embodiment or versions of the components and methods involved in this system are presented, others would be possible. For example, while the HSP Center is described in a preferred form, this “center” could be established in various ways. For example, personnel already employed by the School District (or additional employees hired by the School District) could simply function directly out of the School District facilities. Alternatively, this HSP Center could be established as a separate unit, with the personnel still being employees of the school district. Yet another alternative form would be to establish the HSP Center as a distinct group, and even to the extent that it could be acting as a separate legal entity having a contractual working relationship with the school district. Such things would depend upon the educational system in that state and other factors.
It is to be understood that the various terms used herein and in the appended claims are within the broader scope of the present invention to be given their broadest meaning. For example, as indicated previously, the term “School District” is (as discussed earlier in this text) intended to refer to an educational entity which provides education in large part in a classroom environment, and the term “Parent” is interpreted more broadly to include a guardian or other responsible person or persons for the home school student.
As a final note, it should again be emphasized that one of the primary goals of this system is to develop a system that “bridges the gap” which has developed between established education and home schoolers, find out what they have in common and how they can benefit from cooperating with one another, and then putting the system into practice.
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An educational system to enhance the benefits derived from home schooling. A Home Schooling Program Center is established to coordinate between an existing school district and the home schooling units (i.e. the parent (s) and the student being home schooled). This Center enrolls the home school student as a student in the school district and assists the home school parents in accomplishing the proper education of the student. Various educational equipment, texts and other aids are provided. The home school students are periodically tested and gain full credit as other students enrolled in the school program, so that the student could qualify for further education and be fully certified high school graduates.
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FIELD OF THE INVENTION
The present invention is related to beverage brewing elements and systems, and in particular, to a brewing element provided with a central perforated inlet for use in espresso-type machines and portable beverage brewing systems.
BACKGROUND OF THE INVENTION
A small, cylindrical chamber is used in home and office espresso machines to hold a cylindrical capsule or pod containing a measured amount of dry, ground materials used in brewing, such as coffee. The cylindrical chamber, generally made of aluminum foil or heat-resistant plastic, encloses the capsule, and the top and the base of the cylinder are perforated to allow pressurized, heated water to enter the cylinder from the top, flushing axially through the capsule and exiting through the perforated base as an espresso beverage directed from a spout into a receptacle, such as a coffee cup.
Since the espresso preparation procedure involves the use of high pressure water flushing through the brewing materials, such as ground coffee, and this pressure develops very high radial forces on the face of the cylinder envelope, a very rigid, construction is needed to support the capsule and seal the capsule faces during the preparation process. Such rigid construction increases the cost of producing the brewing machine and the cost to the consumer is like-wise higher.
The problem of rigid construction of a capsule for espresso machines also applies to portable brewing systems since the capsule for the dry comestibles need to be held firmly in place on all sides while being subjected to the pressure of heated water applied axially to the capsule and this action produces very high forces both in axial and radial directions.
In U.S. Pat. No. 4,382,402 to Alvarez, for example, the inventor describes a portable coffee maker having a water-heating chamber and a coffee-brewing chamber. This prior art invention has the disadvantage of requiring a rigid support for the separate chambers which adds to the cost of the system.
In U.S. Pat. No. 6,740,345 to Cai, the inventor describes the use of a rigid wall construction of a cartridge which is bulb-shaped and which, dispenses its ingredients when impacted by heated, pressurized water passed axially from an upper, impermeable chamber to the lower one utilizing a through opening in the cartridge. The rigid wall construction of cartridges is more costly to manufacture, as heretofore mentioned, and therefore may result in a product that is expensive when made for one-time use. It also creates greater waste since the sturdier materials tend to be harder on the environment than might be desirable.
In U.S. Pat. No. 6,658,989 to Sweeney el al, the inventor describes a re-usable beverage filter cartridge in a cup-shaped housing provided with dual chambers, closed at the bottom, and having an outlet port. The cartridge is subjected to a stream of heated, pressurized water to mix with the ingredients in a first chamber, and, after passing through a filtering medium, the resultant brew is directed into a second chamber. The disadvantage noted heretofore applies to this cartridge as well, since it is manufactured with a rigid, structure comprising dual chambers.
SUMMARY OF THE INVENTION
The present invention is an improvement over the prior art by providing a new and improved type of brewing element which eliminates the need for rigid and complicated construction or the provision of a supportive structure, such as a special rigid chamber, which is ordinarily needed to firmly hold the capsule in place in a beverage-brewing device during the preparation process.
Therefore it is an object of the present invention to provide a brewing element comprising: a capsule for storing at least one comestible brewing ingredient therein; and an attachment means for removably attaching the element to a container, the element having formed therein a central inlet for admitting pressurized, heated water and a peripheral outlet for releasing a mixture of the at least one comestible brewing ingredient with the pressurized, heated water, wherein when the brewing element is incorporated into an operating beverage brewing system, the capsule releases the mixture multi-directionally through the peripheral outlet to provide a brewed beverage into the container.
This new type of brewing element will also allow the production of a more flexible, greatly simplified, and less-expensive mechanism for the next generation of espresso machines.
The inventive concept is based on a brewing element formed as a hollow, cylindrical capsule having a toroidal-like shape, like that of a car tire, containing at least one ingredient for making a brewed beverage. The hollow capsule is perforated in its central bore and about its outer surface in such a way as to provide for the passage of high-pressure water into and out of the envelope of the capsule. A novel feature of this capsule is that it provides multi-directional venting of the brew through perforations in the outer wall of the envelope along its periphery.
The pressurized water enters the capsule through a tube inserted axially into the centrally disposed bore of the capsule and flows out by flushing through the brewing material contained in the envelope in multiple directions, both axially and radially. The mixed brew exits the capsule through the outer, perforated envelope. A finger-like tube with a few radial drills tightly engages with the central opening of the capsule and supplies the pressurized water through the central bore which is advantageously provided with a perforated surface so as to allow the pressurized water to flush through the brewing materials, such as ground coffee, or any other comestible suitable for brewing.
Since forces are both axial and radial, there is no further need to axially support the capsule as is commonly done in existing espresso systems. In the case of the present invention, the axial force needed to hold the capsule in place is the water pressure multiplied by the inlet tube section area which is negligible compared to the face of a conventional capsule. The ratio is about 1:20 in the sections and therefore 1:20 in holding forces. For example, for 16 bar machines the holding force ratio will be 2.4 kg. against 48 kg.
The internal radial forces will blow the capsule upon application of pressure from the water rapidly filling the inside of the toroidal-like capsule. The unique properties of the toroidal-like shape will cause it to behave much as a car tire which it resembles, but just as a tire, which is made of pliable rubber, can hold an internal pressure without any external support, so too the capsule will retain sufficient strength to fulfill its function and dispense a hot brewed beverage.
BRIEF DESCRIPTION OF THE DRAWINGS
Attention is now directed to the attached drawings, wherein like reference numerals or characters indicate corresponding or like components. In the drawings:
FIG. 1 is a cross-sectional view of an embodiment of the capsule of the present invention shown connected directly to a high-pressure water pump in a portable beverage brewing system;
FIG. 2 is an isometric drawing of the embodiment of the capsule shown in FIG. 1 indicating the flow of pressurized water into the capsule through a central bore inlet and out of the capsule through perforations in the outer envelope;
FIG. 3 is a cross-sectional view of the embodiment of the invention of FIG. 2 ;
FIG. 4 is a cross-sectional view of an implementation of the capsule of FIG. 3 showing an inlet tube having an open end inserted into the central blind bore;
FIG. 5 is a cross-sectional view of another embodiment of the present invention provided with a through-hole in its central bore;
FIG. 6 is a cross-sectional view of an implementation of the capsule of FIG. 5 shown fitted with a closed-ended inlet tube;
FIG. 7 is an isometric view of another embodiment of the invention provided with a small, perforated media, sealed into and partially blocking the inlet to a central bore;
FIG. 8 is a cross-sectional view of yet another embodiment of the invention shown in FIG. 7 ; and
FIG. 9 is a cross-sectional view of an implementation of the embodiment of FIG. 8 showing an application wherein a pair of inlet tubes are shown removably attached to each end of a central bore.
DETAILED DESCRIPTION OF THE EMBODIMENTS
FIG. 1 is a cross-sectional view of an embodiment of the capsule of the present invention shown connected directly to a high-pressure water pump in a portable beverage brewing system, such as an espresso machine.
The portable beverage brewing system comprises: a power and control unit 44 connected to a power source connector 46 , for example, an auto cigarette lighter plug, and connected to a length of heater element 48 for heating the water for making a brew; a water suction pump 50 and suction tube 52 for drawing water 54 (shown as wavy lines) from a container 56 , such as a cup, into the hot water pumping section 58 ; a high pressure pump 60 to create the necessary pressure to flush the water through the inner and outer envelope 62 of a brewing element 64 , such as the toroidal-like capsule of the present invention; and a housing unit 66 for containing the various power and control components of the system which is shown mounted as a sealed unit to cup 56 where the brew is collected.
Note that the housing unit 66 is removable after the brew has been prepared and may be reused with the same container simply by selecting a new cover with another brewing element. Container 56 is provided with a cover 68 having two inlets 70 a/b to accommodate and attach the housing unit to container 56 . One inlet 70 a introduces suction tube 52 into container 56 (and may also be used as a mouthpiece for drinking the prepared brew) while the other admits nozzle 72 into the central bore of brewing element 64 , thus allowing pressurized water to flow (as shown by down arrow) through inlet 70 b when the espresso machine is turned on and operating.
Cover 68 serves as an attachment means for the brewing element of the invention. The brewing element is attached on the underside of cover 68 . The cover acts as a register to align the capsule so that it fits into cup 56 in the center and the capsule is also spaced apart from the adjacent surfaces of the inside of cup 56 . This is necessary in order for the vented brew to exit the peripheral outlet. This feature allows a user to choose alternate brews for drinking simply by replacing the covers on the container.
Note also that brewing element 64 is provided with a perforated envelope which allows multi-directional venting of the mixed brew. The flushed brew flows not just axially downward as in prior art brewing elements, but also radially outward, as shown by the multiple arrows 74 , and thus fill container 56 with a predetermined volume of a heated brew, such as coffee.
FIG. 2 is an isometric drawing of the embodiment of the capsule shown in FIG. 1 indicating the flow of pressurized water into the capsule through a central bore inlet and out of the capsule through perforations in the outer envelope.
The perforated capsule 64 is shown with inlet 76 that serves to admit pressurized water (indicated by downward arrow) to flush a brew through the perforations 74 in perforated envelope 62 when capsule 64 is inserted into an espresso machine and the machine is operated.
It should be noted that although the perforations shown in FIG. 2 (and also FIG. 7 ) are formed in a uniform manner on the outer periphery of the brewing element, alternate arrangements or even random placement may also be utilized and it is not to be construed as a limitation of the present invention, but this arrangement is only shown by way of example.
A fabric or paper filter (not shown) is used between the ground coffee and the perforated envelope 62 . Note that the novel toroidal-like shape of the capsule 64 provides sufficient structural support to permit use of it without the use of complicated supporting members or ribbing in either an espresso machine or in the retaining cup of a portable brewing system. This feature allows for a simpler and less expensive construction of espresso machines and related systems.
FIG. 3 is a cross-sectional view of the embodiment of the invention of FIG. 2 . The lower end 78 of inlet 76 is closed forming a blind bore. Inlet 76 is also provided with a tight seal 80 around its lip to firmly attach a high pressure water tube (see FIG. 4 ) such as from an espresso machine. The pressurized water is forced through holes 73 in the walls of the inlet 76 and flushes through a brewing preparation 28 , such as coffee. Multiple arrows indicate the direction of pressurized water flow exiting through perforations 74 in the outer wall of the capsule 64 .
FIG. 4 is a cross-sectional view of an implementation of capsule 64 of FIG. 3 showing a pressurized water inlet tube 84 , having an open end 86 inserted into inlet 76 (see FIG. 3 ) to allow pressurized water to be introduced into capsule 64 to flush through and flush out the brewing preparation 28 , such as coffee, contained therein. The inlet tube 84 is held snugly in place by seal 80 . Arrows indicate the radial dispersion and flushing of pressurized water through bore holes 73 and perforations 74 .
FIG. 5 is a cross-sectional view of another embodiment of the present invention provided with a through-hole in its central bore defined by inlet 76 and outlet 77 . A seal 81 is provided around the circumference of the through-hole at both inlet 76 and outlet 77 .
FIG. 6 is a cross-sectional view of an implementation of the invention of FIG. 5 shown fitted with a closed-ended inlet tube.
In this embodiment of the present invention, capsule 88 is fitted with a closed-ended inlet tube 90 provided with a few radial holes 92 to admit pressurized water (shown by downward arrow) into the capsule brewing element 88 and to flush through and flush out the brewing preparation 28 , such as coffee, contained therein through the perforations 74 in the outer envelope 62 of capsule brewing element 88 . Note that inlet tube 90 extends below the through hole 77 and is closed at tube end 94 .
FIG. 7 is an isometric view of another embodiment of the invention provided with a small, perforated media, sealed into and partially blocking the inlet to a central bore, Capsule brewing element 96 is also toroidal-like shape to provide structural strength. It is fitted with perforations 74 on the outside wall of the envelope forming a peripheral outlet for venting a pressurized brew into a cup or other container in an espresso brewing system. In this embodiment of the invention, the inlet (indicated by downward arrow) to the central bore (not visible) is sealed with a perforated media 98 , such as an inlet cap.
FIG. 8 is a cross-sectional view of yet another embodiment of the invention shown in FIG. 7 . Note that both ends of central bore 76 are partially blocked by the perforated media 98 and 97 respectively. Both upper and lower lips of the central bore 76 are provided with seals 80 and 81 , respectively.
FIG. 9 is a cross-sectional view of an implementation of the embodiment of FIG. 8 showing an application wherein a pair of inlet tubes are shown removably-attached to each end of a central bore. An upper tube 100 and a lower tube 99 are removably-attached to the inlet 76 of capsule brewing element 96 . The tubes are constructed so as to fit snugly into the upper and lower inlets 76 in the respective ends of the central bore and held in place by seals 80 and 81 , respectively. The tubes 100 , 99 are immobilized against perforated media 98 , 97 and pressurized water (indicated by broad arrows) are partially blocked from entering the inlets 76 except through the perforations in the perforated media 97 , 98 .
It should be noted that if the capsule brewing element in the implementation described above is fitted with only one open-ended tube, either upper tube 100 or lower tube 99 , it is recommended to insert a blocking cylinder (not shown) on the other end to balance the axial force resulting from water pressure when pressurized water is admitted into the inlet 76 to the central bore.
Having described the present invention with regard to certain specific embodiments thereof, it is to be understood that the description is not meant as a limitation, since further modifications may now suggest themselves to those skilled in the art, and it is intended to cover such modifications as fall within the scope of the appended claims of the present invention.
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A brewing element comprising an envelope for storing at least one comestible brewing ingredient therein; and an attachment means for removably attaching the element to a container, the element having formed therein a central inlet for admitting pressurized, heated water and a peripheral outlet for releasing a mixture of the at least one comestible brewing ingredient with the pressurized, heated water, wherein when the brewing element is incorporated into an operating beverage brewing system, the capsule releases the mixture multi-directionally through the peripheral outlet to provide a brewed beverage into the container.
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